/* ============================================================
   ИИ-пособие по химии · СИБУР × Просвещение
   Дизайн-макет v01 — дизайн-система «Молекулярная лаборатория»
   ============================================================ */

:root {
  /* фон и поверхности */
  --bg: #040b1e;
  --bg-2: #07132e;
  --panel: #0b1d44;
  --panel-2: #0f2657;
  --line: rgba(95, 196, 255, .18);
  --line-strong: rgba(95, 196, 255, .45);

  /* акценты */
  --cyan: #4fd8ff;
  --blue: #2f6bff;
  --blue-deep: #1848c8;
  --teal: #149aa8;       /* СИБУР */
  --mint: #77e2c3;       /* СИБУР */
  --yellow: #ffc83d;     /* валентность / «Ученикам» Просвещения */
  --orange: #eca438;
  --red: #ff4d5e;

  /* текст */
  --text: #eaf2ff;
  --muted: #93a7cc;
  --dim: #5f7299;

  /* светлая «лабораторная» поверхность */
  --ice: #eef5ff;
  --ice-2: #dce9fb;
  --ink: #0b1633;
  --ink-muted: #4a5b80;

  --radius: 20px;
  --radius-sm: 12px;
  --container: 1240px;
  --header-h: 72px;

  --font: "Onest", "TT Interfaces", system-ui, -apple-system, "Segoe UI", Arial, sans-serif;
  --mono: "JetBrains Mono", ui-monospace, "SF Mono", Menlo, monospace;
}

*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  font-family: var(--font);
  font-size: 17px;
  line-height: 1.55;
  color: var(--text);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}
img, video { display: block; max-width: 100%; }
a { color: inherit; text-decoration: none; }
button { font: inherit; color: inherit; cursor: pointer; border: 0; background: none; }
sub { font-size: .62em; line-height: 0; vertical-align: -.25em; }

.container { width: 100%; max-width: var(--container); margin: 0 auto; padding: 0 32px; }
@media (max-width: 767px) { .container { padding: 0 16px; } }

/* ---------- типографика ---------- */
.h1 { font-size: clamp(40px, 6.2vw, 84px); line-height: 1; letter-spacing: -.03em; font-weight: 700; margin: 0; }
.h2 { font-size: clamp(32px, 4.2vw, 56px); line-height: 1.05; letter-spacing: -.025em; font-weight: 700; margin: 0; }
.h3 { font-size: clamp(22px, 2.2vw, 28px); line-height: 1.2; letter-spacing: -.01em; font-weight: 600; margin: 0; }
.lead { font-size: clamp(18px, 1.6vw, 21px); line-height: 1.5; color: var(--muted); margin: 0; }
.label {
  font-family: var(--mono); font-size: 12px; letter-spacing: .12em; text-transform: uppercase;
  color: var(--cyan); display: inline-flex; align-items: center; gap: 10px;
}
.label::before { content: ""; width: 18px; height: 1px; background: currentColor; }
.grad-text { background: linear-gradient(92deg, #fff 0%, var(--cyan) 55%, var(--mint) 100%); -webkit-background-clip: text; background-clip: text; color: transparent; }
.yellow { color: var(--yellow); }

.section { padding: 120px 0; position: relative; }
.section-head { display: flex; justify-content: space-between; align-items: end; gap: 32px; margin-bottom: 48px; flex-wrap: wrap; }
.section-head .lead { max-width: 520px; }
@media (max-width: 767px) { .section { padding: 72px 0; } .section-head { margin-bottom: 32px; } }

/* ---------- кнопки ---------- */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 10px;
  height: 56px; padding: 0 28px; border-radius: 14px;
  font-weight: 600; font-size: 17px; white-space: nowrap;
  transition: transform .2s, box-shadow .2s, background .2s, border-color .2s;
}
.btn:active { transform: translateY(1px); }
.btn-primary { background: var(--yellow); color: #1a1300; box-shadow: 0 8px 30px -8px rgba(255, 200, 61, .6); }
.btn-primary:hover { box-shadow: 0 10px 40px -6px rgba(255, 200, 61, .85); transform: translateY(-2px); }
.btn-ghost { border: 1px solid var(--line-strong); color: var(--text); background: rgba(11, 29, 68, .45); backdrop-filter: blur(8px); }
.btn-ghost:hover { border-color: var(--cyan); background: rgba(79, 216, 255, .08); }
.btn-dark { background: var(--ink); color: #fff; }
.btn-dark:hover { background: var(--blue-deep); }
.btn-sm { height: 44px; padding: 0 18px; font-size: 15px; border-radius: 12px; }
.btn .play-ic { width: 28px; height: 28px; border-radius: 50%; background: var(--cyan); display: grid; place-items: center; color: var(--bg); }
.btn .play-ic svg { width: 12px; height: 12px; margin-left: 2px; }

/* ---------- HUD-рамка (как панели в роликах) ---------- */
.hud { position: relative; border: 1px solid var(--line); border-radius: var(--radius); background: linear-gradient(180deg, rgba(15, 38, 87, .7), rgba(7, 19, 46, .7)); }
.hud::before, .hud::after {
  content: ""; position: absolute; width: 22px; height: 22px; pointer-events: none;
  border: 2px solid var(--cyan); filter: drop-shadow(0 0 6px rgba(79, 216, 255, .7));
}
.hud::before { top: -1px; left: -1px; border-right: 0; border-bottom: 0; border-top-left-radius: var(--radius); }
.hud::after { bottom: -1px; right: -1px; border-left: 0; border-top: 0; border-bottom-right-radius: var(--radius); }

.chip {
  display: inline-flex; align-items: center; gap: 8px; height: 32px; padding: 0 12px;
  border-radius: 999px; font-size: 13px; font-weight: 500; white-space: nowrap;
  border: 1px solid var(--line); color: var(--muted); background: rgba(7, 19, 46, .6);
}
.chip .dot { width: 7px; height: 7px; border-radius: 50%; background: var(--mint); box-shadow: 0 0 10px var(--mint); }
.chip.soon .dot { background: var(--dim); box-shadow: none; }
.chip.new { color: #1a1300; background: var(--yellow); border-color: transparent; font-weight: 600; }

/* ============================================================
   ШАПКА (хром prosv.ru)
   ============================================================ */
.site-header {
  position: fixed; inset: 0 0 auto 0; z-index: 50; height: var(--header-h);
  transition: background .3s, box-shadow .3s, color .3s; color: #fff;
}
.site-header.is-solid { background: #fff; color: var(--ink); box-shadow: 0 1px 0 rgba(11, 22, 51, .08); }
.site-header .container { height: 100%; display: flex; align-items: center; gap: 40px; }
.logo-prosv { display: flex; align-items: center; }
.logo-prosv svg { width: 118px; height: auto; }
.site-header nav { display: flex; gap: 32px; font-size: 15px; font-weight: 500; margin: 0 auto; }
.site-header nav a { opacity: .88; transition: opacity .2s; }
.site-header nav a:hover { opacity: 1; }
.login {
  display: inline-flex; align-items: center; gap: 8px; height: 40px; padding: 0 16px; border-radius: 999px;
  font-size: 14px; font-weight: 500; background: rgba(255, 255, 255, .14); backdrop-filter: blur(8px);
}
.site-header.is-solid .login { background: #eef1f8; color: #2c4fa8; }
.burger { display: none; width: 40px; height: 40px; border-radius: 10px; background: rgba(255,255,255,.14); place-items: center; }
.site-header.is-solid .burger { background: #eef1f8; }
@media (max-width: 1023px) {
  .site-header nav { display: none; }
  .burger { display: grid; }
  .login { margin-left: auto; }
  .login span { display: none; }
  .login { padding: 0 11px; }
}

/* ============================================================
   HERO
   ============================================================ */
.hero { position: relative; min-height: 100vh; min-height: 100svh; display: flex; align-items: flex-end; overflow: hidden; padding: calc(var(--header-h) + 40px) 0 56px; }
.hero-media { position: absolute; inset: 0; }
.hero-media video, .hero-media img { width: 100%; height: 100%; object-fit: cover; object-position: 62% 30%; }
.hero-media::after {
  content: ""; position: absolute; inset: 0;
  background:
    linear-gradient(90deg, rgba(4, 11, 30, .95) 0%, rgba(4, 11, 30, .78) 34%, rgba(4, 11, 30, .15) 64%, rgba(4, 11, 30, .25) 100%),
    linear-gradient(0deg, var(--bg) 0%, rgba(4, 11, 30, 0) 38%),
    linear-gradient(180deg, rgba(4, 11, 30, .55) 0%, rgba(4, 11, 30, 0) 20%);
}
.hero .container { position: relative; z-index: 2; }
.hero-grid { display: grid; grid-template-columns: minmax(0, 1.25fr) minmax(0, 1fr); gap: 48px; align-items: end; }
.cobrand { display: flex; align-items: center; gap: 18px; margin-bottom: 36px; }
.cobrand img { height: 26px; width: auto; }
.cobrand .x { color: var(--muted); font-size: 18px; }
.cobrand svg { width: 104px; color: #fff; }
.hero .badge-row { display: flex; gap: 10px; flex-wrap: wrap; margin-bottom: 24px; }
.hero .h1 { margin-bottom: 24px; }
.hero .lead { max-width: 560px; margin-bottom: 36px; color: #c4d3ef; }
.hero-actions { display: flex; gap: 14px; flex-wrap: wrap; }

.hero-stats { display: grid; grid-template-columns: repeat(4, 1fr); margin-top: 64px; border-top: 1px solid var(--line); }
.hero-stats > div { padding: 22px 24px 0 0; }
.hero-stats b { display: block; font-size: clamp(28px, 3vw, 40px); line-height: 1; letter-spacing: -.02em; font-weight: 700; }
.hero-stats span { font-size: 14px; color: var(--muted); }

/* плавающие метки у ведущего */
.hero-float { position: relative; height: 100%; min-height: 420px; }
.float-tag {
  position: absolute; padding: 10px 14px; border-radius: 14px; font-family: var(--mono); font-size: 13px;
  background: rgba(7, 19, 46, .72); border: 1px solid var(--line-strong); backdrop-filter: blur(10px);
  box-shadow: 0 0 30px -6px rgba(79, 216, 255, .5); animation: floaty 6s ease-in-out infinite;
}
.float-tag b { font-family: var(--font); font-size: 22px; display: block; color: #fff; letter-spacing: -.01em; }
.float-tag i { font-style: normal; color: var(--yellow); }
.float-tag.t1 { top: 6%; right: 6%; }
.float-tag.t2 { top: 44%; right: 58%; animation-delay: -2s; }
.float-tag.t3 { bottom: 4%; right: 12%; animation-delay: -4s; }
@keyframes floaty { 0%, 100% { transform: translateY(0); } 50% { transform: translateY(-10px); } }

.scroll-hint { position: absolute; left: 50%; bottom: 18px; transform: translateX(-50%); z-index: 2; color: var(--dim); font-family: var(--mono); font-size: 11px; letter-spacing: .16em; }

@media (max-width: 1023px) {
  .hero-grid { grid-template-columns: 1fr; }
  .hero-float { display: none; }
  .hero-media video, .hero-media img { object-position: 70% 20%; }
  .hero-media::after { background: linear-gradient(0deg, var(--bg) 8%, rgba(4, 11, 30, .82) 48%, rgba(4, 11, 30, .25) 100%); }
}
@media (max-width: 767px) {
  .hero { padding-bottom: 32px; }
  .hero-stats { grid-template-columns: repeat(2, 1fr); margin-top: 40px; }
  .hero-stats > div { padding-top: 18px; }
  .hero-actions .btn { flex: 1 1 100%; }
  .cobrand { margin-bottom: 24px; }
}

/* ============================================================
   QR → урок → тренажёр
   ============================================================ */
.qr-strip { padding: 40px 0 0; }
.steps { display: grid; grid-template-columns: 1.1fr 1fr 1fr 1fr; gap: 16px; }
.step { padding: 28px; min-height: 220px; display: flex; flex-direction: column; }
.step .num { font-family: var(--mono); font-size: 13px; color: var(--cyan); margin-bottom: auto; }
.step .ic { width: 52px; height: 52px; border-radius: 14px; display: grid; place-items: center; background: rgba(79, 216, 255, .1); color: var(--cyan); margin-bottom: 18px; }
.step .ic svg { width: 26px; height: 26px; }
.step h3 { font-size: 20px; margin: 0 0 6px; font-weight: 600; letter-spacing: -.01em; }
.step p { margin: 0; color: var(--muted); font-size: 15px; }
.step-find { background: linear-gradient(140deg, #123a8f 0%, #0b1d44 70%); }
.step-find h3 { font-size: 24px; }
.para-search { margin-top: 18px; display: flex; gap: 8px; }
.para-search input {
  flex: 1; min-width: 0; height: 48px; border-radius: 12px; border: 1px solid var(--line-strong); background: rgba(4, 11, 30, .5);
  color: #fff; font: inherit; font-size: 15px; padding: 0 14px; outline: none;
}
.para-search input:focus { border-color: var(--cyan); box-shadow: 0 0 0 3px rgba(79, 216, 255, .2); }
.para-search button { width: 48px; height: 48px; border-radius: 12px; background: var(--cyan); color: var(--bg); display: grid; place-items: center; }
@media (max-width: 1023px) { .steps { grid-template-columns: 1fr 1fr; } .step-find { grid-column: 1 / -1; } }
@media (max-width: 599px) { .steps { grid-template-columns: 1fr; } .step { min-height: 0; } .step .num { margin-bottom: 18px; } }

/* ============================================================
   ТЕМЫ
   ============================================================ */
.filters { display: flex; gap: 8px; flex-wrap: wrap; }
.filter { height: 40px; padding: 0 16px; border-radius: 999px; border: 1px solid var(--line); color: var(--muted); font-size: 14px; font-weight: 500; }
.filter.is-active { background: var(--text); color: var(--bg); border-color: var(--text); }

.topics { display: grid; grid-template-columns: repeat(12, 1fr); gap: 20px; }
.topic { grid-column: span 6; overflow: hidden; display: flex; flex-direction: column; transition: transform .3s, border-color .3s; }
.topic:hover { transform: translateY(-4px); border-color: var(--line-strong); }
.topic-cover { position: relative; aspect-ratio: 16 / 8; overflow: hidden; border-radius: var(--radius) var(--radius) 0 0; }
.topic-cover img { width: 100%; height: 100%; object-fit: cover; transition: transform .6s; }
.topic:hover .topic-cover img { transform: scale(1.04); }
.topic-cover::after { content: ""; position: absolute; inset: 0; background: linear-gradient(0deg, rgba(7, 19, 46, 1) 0%, rgba(7, 19, 46, 0) 55%); }
.topic-cover .chip { position: absolute; top: 16px; left: 16px; z-index: 2; background: rgba(4, 11, 30, .7); backdrop-filter: blur(8px); }
.topic-num { position: absolute; right: 20px; bottom: 6px; z-index: 2; font-size: 96px; font-weight: 800; line-height: 1; letter-spacing: -.05em; color: transparent; -webkit-text-stroke: 1px rgba(79, 216, 255, .55); }
.topic-body { padding: 4px 28px 28px; display: flex; flex-direction: column; gap: 16px; flex: 1; }
.topic-body .label { font-size: 11px; }
.topic-body h3 { font-size: 26px; line-height: 1.15; margin: 0; font-weight: 600; letter-spacing: -.015em; }
.topic-meta { display: flex; gap: 18px; color: var(--muted); font-size: 14px; flex-wrap: wrap; }
.topic-lessons { display: grid; grid-template-columns: repeat(4, 1fr); gap: 8px; margin-top: auto; }
.mini { position: relative; aspect-ratio: 16 / 10; border-radius: 10px; overflow: hidden; background: var(--panel-2); border: 1px solid var(--line); }
.mini img { width: 100%; height: 100%; object-fit: cover; }
.mini span { position: absolute; left: 6px; bottom: 5px; font-family: var(--mono); font-size: 10px; color: #fff; text-shadow: 0 1px 4px #000; }
.mini.locked { display: grid; place-items: center; color: var(--dim); }
.mini.locked svg { width: 16px; height: 16px; }
.progress { height: 4px; border-radius: 4px; background: rgba(147, 167, 204, .18); overflow: hidden; }
.progress i { display: block; height: 100%; background: linear-gradient(90deg, var(--cyan), var(--mint)); border-radius: 4px; }
.topic-foot { display: flex; align-items: center; justify-content: space-between; gap: 12px; font-size: 14px; color: var(--muted); }
.topic-foot .go { display: inline-flex; align-items: center; gap: 8px; color: var(--text); font-weight: 600; }
.topic-foot .go svg { width: 18px; height: 18px; transition: transform .2s; }
.topic:hover .go svg { transform: translateX(4px); }

/* скоро */
.topic.is-soon { grid-column: span 4; }
.topic.is-soon .topic-cover { aspect-ratio: 16 / 9; background: radial-gradient(120% 90% at 70% 20%, #16347a 0%, #07132e 60%); }
.soon-formula { position: absolute; inset: 0; display: grid; place-items: center; font-size: 44px; font-weight: 700; letter-spacing: -.02em; color: rgba(147, 167, 204, .28); z-index: 1; }
.soon-formula::before { content: ""; position: absolute; width: 180px; height: 180px; border-radius: 50%; border: 1px dashed rgba(79, 216, 255, .25); animation: spin 40s linear infinite; }
@keyframes spin { to { transform: rotate(360deg); } }
.topic.is-soon .topic-num { font-size: 64px; -webkit-text-stroke-color: rgba(147, 167, 204, .3); }
.topic.is-soon h3 { font-size: 21px; }
.topic.is-soon .topic-foot { color: var(--dim); }
.notify { display: inline-flex; align-items: center; gap: 6px; color: var(--cyan); font-weight: 500; }

@media (max-width: 1023px) { .topic, .topic.is-soon { grid-column: span 12; } .topic.is-soon { grid-column: span 6; } }
@media (max-width: 767px) { .topic.is-soon { grid-column: span 12; } .topic-body { padding: 4px 18px 20px; } .topic-num { font-size: 72px; } }

/* ============================================================
   НАЧНИ ОТСЮДА (featured)
   ============================================================ */
.featured { display: grid; grid-template-columns: minmax(0, 1.55fr) minmax(0, 1fr); gap: 20px; }
.player-card { position: relative; border-radius: var(--radius); overflow: hidden; aspect-ratio: 16 / 9; background: #000; cursor: pointer; }
.player-card img { width: 100%; height: 100%; object-fit: cover; transition: transform .6s, opacity .3s; }
.player-card:hover img { transform: scale(1.03); }
.player-card::after { content: ""; position: absolute; inset: 0; background: linear-gradient(0deg, rgba(4, 11, 30, .85) 0%, rgba(4, 11, 30, 0) 50%); }
.big-play {
  position: absolute; left: 50%; top: 50%; transform: translate(-50%, -50%); z-index: 2;
  width: 96px; height: 96px; border-radius: 50%; display: grid; place-items: center;
  background: rgba(79, 216, 255, .18); border: 1px solid rgba(79, 216, 255, .7); backdrop-filter: blur(10px);
  box-shadow: 0 0 0 12px rgba(79, 216, 255, .08), 0 0 60px rgba(79, 216, 255, .5); transition: transform .25s;
}
.big-play svg { width: 30px; height: 30px; margin-left: 5px; color: #fff; }
.player-card:hover .big-play { transform: translate(-50%, -50%) scale(1.08); }
.player-cap { position: absolute; left: 28px; right: 28px; bottom: 24px; z-index: 2; display: flex; justify-content: space-between; align-items: end; gap: 16px; }
.player-cap h3 { font-size: clamp(22px, 2.4vw, 32px); margin: 6px 0 0; font-weight: 600; letter-spacing: -.02em; line-height: 1.1; }
.player-cap .time { font-family: var(--mono); font-size: 13px; padding: 6px 10px; border-radius: 8px; background: rgba(4, 11, 30, .7); }

.chapters { padding: 28px; display: flex; flex-direction: column; }
.chapters h3 { font-size: 20px; margin: 10px 0 18px; font-weight: 600; }
.chapter { display: grid; grid-template-columns: 56px 1fr; gap: 12px; padding: 12px 0; border-top: 1px solid var(--line); font-size: 15px; align-items: baseline; }
.chapter:hover .ch-title { color: var(--cyan); }
.chapter .t { font-family: var(--mono); font-size: 13px; color: var(--cyan); }
.ch-title { transition: color .2s; }
.chapters .btn { margin-top: auto; }
@media (max-width: 1023px) { .featured { grid-template-columns: 1fr; } }
@media (max-width: 767px) { .big-play { width: 72px; height: 72px; } .player-cap { left: 16px; right: 16px; bottom: 14px; } .player-cap .time { display: none; } }

/* ============================================================
   ВЕДУЩИЙ
   ============================================================ */
.host { position: relative; overflow: hidden; border-radius: 28px; min-height: 640px; display: grid; grid-template-columns: 1fr 1fr; background: #cfe3fb; }
.host-bg { position: absolute; inset: 0; background: url(../assets/img/lab.jpg) center 30% / cover; filter: blur(3px) saturate(1.1); transform: scale(1.06); }
.host-bg::after { content: ""; position: absolute; inset: 0; background: linear-gradient(90deg, rgba(4, 11, 30, .96) 0%, rgba(4, 11, 30, .82) 42%, rgba(4, 11, 30, .1) 75%); }
.host-copy { position: relative; z-index: 2; padding: 64px; display: flex; flex-direction: column; justify-content: center; gap: 22px; }
.host-copy .lead { color: #c4d3ef; }
.host-img { position: relative; z-index: 1; align-self: end; justify-self: center; height: 100%; display: flex; align-items: flex-end; }
.host-img img { height: 600px; width: auto; object-fit: contain; filter: drop-shadow(0 30px 60px rgba(0, 0, 0, .5)); }
.tag-fashion {
  position: absolute; z-index: 3; right: 8%; top: 18%; transform: rotate(4deg);
  background: var(--teal); color: #fff; font-weight: 700; letter-spacing: .04em; text-transform: uppercase;
  padding: 12px 18px; border-radius: 10px; font-size: 18px; box-shadow: 0 16px 40px -10px rgba(20, 154, 168, .8);
}
.host-facts { display: flex; gap: 10px; flex-wrap: wrap; }
.host-facts .chip { background: rgba(79, 216, 255, .08); color: var(--text); height: 36px; }
@media (max-width: 1023px) {
  .host { grid-template-columns: 1fr; min-height: 0; }
  .host-bg::after { background: linear-gradient(0deg, rgba(4, 11, 30, .96) 45%, rgba(4, 11, 30, .2) 100%); }
  .host-img { order: -1; height: auto; }
  .host-img img { height: 380px; }
  .host-copy { padding: 0 24px 40px; }
  .tag-fashion { top: 40px; right: 16px; font-size: 14px; }
}

/* ============================================================
   ФОРМАТЫ УРОКОВ
   ============================================================ */
.formats { display: grid; grid-template-columns: repeat(4, 1fr); gap: 16px; }
.format { overflow: hidden; display: flex; flex-direction: column; }
.format-img { aspect-ratio: 4 / 3; overflow: hidden; border-radius: var(--radius) var(--radius) 0 0; position: relative; }
.format-img img { width: 100%; height: 100%; object-fit: cover; transition: transform .6s; }
.format:hover .format-img img { transform: scale(1.05); }
.format-body { padding: 22px 22px 26px; }
.format-body .n { font-family: var(--mono); font-size: 12px; color: var(--cyan); }
.format-body h3 { font-size: 22px; margin: 8px 0 8px; font-weight: 600; letter-spacing: -.01em; }
.format-body p { margin: 0; font-size: 15px; color: var(--muted); }
@media (max-width: 1023px) { .formats { grid-template-columns: repeat(2, 1fr); } }
@media (max-width: 599px) {
  .formats { grid-template-columns: none; grid-auto-flow: column; grid-auto-columns: 78%; overflow-x: auto; scroll-snap-type: x mandatory; padding-bottom: 8px; margin: 0 -16px; padding-left: 16px; padding-right: 16px; }
  .format { scroll-snap-align: start; }
}

/* ============================================================
   МИНИ-ТРЕНАЖЁР
   ============================================================ */
.trainer { display: grid; grid-template-columns: minmax(0, .9fr) minmax(0, 1.1fr); gap: 20px; align-items: stretch; }
.trainer-intro { padding: 40px; display: flex; flex-direction: column; gap: 18px; background: radial-gradient(90% 80% at 0% 0%, rgba(47, 107, 255, .35), transparent 60%), linear-gradient(180deg, rgba(15, 38, 87, .7), rgba(7, 19, 46, .7)); }
.levels { display: flex; gap: 8px; align-items: center; margin-top: auto; }
.levels i { width: 40px; height: 6px; border-radius: 6px; background: rgba(147, 167, 204, .2); transition: background .3s, box-shadow .3s; }
.levels i.done { background: var(--mint); box-shadow: 0 0 12px rgba(119, 226, 195, .7); }
.levels i.cur { background: var(--cyan); }
.levels span { font-family: var(--mono); font-size: 12px; color: var(--muted); margin-left: 8px; }

.game { padding: 36px; display: flex; flex-direction: column; gap: 24px; }
.game-q { font-size: 15px; color: var(--muted); display: flex; justify-content: space-between; gap: 12px; flex-wrap: wrap; }
.game-q b { color: var(--text); font-weight: 600; }
.elements { display: flex; justify-content: center; align-items: center; gap: clamp(16px, 5vw, 64px); padding: 12px 0; }
.el { display: flex; flex-direction: column; align-items: center; gap: 14px; }
.el-card {
  position: relative; width: 112px; height: 124px; border-radius: 14px; border: 1px solid var(--line-strong); background: rgba(4, 11, 30, .6);
  display: grid; place-items: center; box-shadow: inset 0 0 30px rgba(79, 216, 255, .08);
}
.el-card .sym { font-size: 52px; font-weight: 700; letter-spacing: -.02em; line-height: 1; }
.el-card .val { position: absolute; top: 8px; left: 10px; font-family: "Times New Roman", serif; font-weight: 700; font-size: 22px; color: var(--yellow); text-shadow: 0 0 12px rgba(255, 200, 61, .6); }
.el-card .name { position: absolute; bottom: 8px; font-size: 11px; color: var(--muted); }
.stepper { display: flex; align-items: center; gap: 6px; background: rgba(4, 11, 30, .6); border: 1px solid var(--line); border-radius: 12px; padding: 4px; }
.stepper button { width: 36px; height: 36px; border-radius: 9px; background: rgba(79, 216, 255, .1); color: var(--cyan); font-size: 20px; line-height: 1; }
.stepper button:hover { background: rgba(79, 216, 255, .22); }
.stepper output { min-width: 28px; text-align: center; font-family: var(--mono); font-size: 18px; font-weight: 600; }
.plus-sign { font-size: 28px; color: var(--dim); padding-bottom: 50px; }
.formula-out {
  text-align: center; font-size: clamp(44px, 6vw, 68px); font-weight: 700; letter-spacing: -.02em; line-height: 1;
  padding: 18px; border-radius: 16px; border: 1px dashed var(--line-strong); transition: border-color .3s, box-shadow .3s, color .3s;
}
.formula-out.ok { border: 1px solid var(--mint); color: var(--mint); box-shadow: 0 0 40px -8px rgba(119, 226, 195, .6); }
.formula-out.bad { border-color: var(--red); animation: shake .4s; }
@keyframes shake { 25% { transform: translateX(-6px); } 75% { transform: translateX(6px); } }
.game-foot { display: flex; align-items: center; justify-content: space-between; gap: 16px; flex-wrap: wrap; }
.hint { font-size: 14px; color: var(--muted); min-height: 22px; }
.hint.ok { color: var(--mint); }
.hint.bad { color: #ff9aa4; }
@media (max-width: 1023px) { .trainer { grid-template-columns: 1fr; } }
@media (max-width: 599px) { .game, .trainer-intro { padding: 22px; } .el-card { width: 92px; height: 104px; } .el-card .sym { font-size: 42px; } .game-foot .btn { width: 100%; } }

/* ============================================================
   ХИМИЯ ВОКРУГ (горизонтальная лента)
   ============================================================ */
.rail { display: grid; grid-auto-flow: column; grid-auto-columns: minmax(300px, 1fr); gap: 16px; overflow-x: auto; scroll-snap-type: x mandatory; padding-bottom: 12px; scrollbar-width: thin; scrollbar-color: var(--panel-2) transparent; }
.world { position: relative; border-radius: var(--radius); overflow: hidden; aspect-ratio: 3 / 4; scroll-snap-align: start; border: 1px solid var(--line); }
.world img { position: absolute; inset: 0; width: 100%; height: 100%; object-fit: cover; transition: transform .6s; }
.world:hover img { transform: scale(1.05); }
.world::after { content: ""; position: absolute; inset: 0; background: linear-gradient(0deg, rgba(4, 11, 30, .96) 8%, rgba(4, 11, 30, .15) 60%); }
.world-body { position: absolute; left: 22px; right: 22px; bottom: 22px; z-index: 2; }
.world-body .formula { font-family: var(--mono); font-size: 14px; color: var(--cyan); padding: 6px 10px; border-radius: 8px; background: rgba(4, 11, 30, .7); border: 1px solid var(--line); display: inline-block; margin-bottom: 12px; }
.world-body h3 { margin: 0 0 6px; font-size: 24px; font-weight: 600; letter-spacing: -.01em; }
.world-body p { margin: 0 0 14px; font-size: 15px; color: #b9c8e6; }
.world-body a { font-size: 14px; font-weight: 600; color: var(--yellow); display: inline-flex; gap: 6px; align-items: center; }
@media (max-width: 767px) { .rail { grid-auto-columns: 80%; margin: 0 -16px; padding-left: 16px; padding-right: 16px; } }

/* ============================================================
   УЧИТЕЛЯМ И РОДИТЕЛЯМ (светлая секция)
   ============================================================ */
.light { background: var(--ice); color: var(--ink); border-radius: 36px 36px 0 0; }
.light + .light-end { background: var(--ice); }
.light .label { color: var(--blue-deep); }
.light .lead { color: var(--ink-muted); }
.audience { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; }
.aud { background: #fff; border-radius: 24px; padding: 40px; display: flex; flex-direction: column; gap: 22px; box-shadow: 0 1px 0 rgba(11, 22, 51, .06), 0 20px 50px -30px rgba(11, 22, 51, .25); }
.aud-top { display: flex; align-items: center; gap: 14px; }
.aud-ic { width: 56px; height: 56px; border-radius: 16px; display: grid; place-items: center; background: #e3edff; color: var(--blue-deep); }
.aud-ic svg { width: 28px; height: 28px; }
.aud.parents .aud-ic { background: #fff1d6; color: #b36b00; }
.aud h3 { font-size: 30px; margin: 0; font-weight: 700; letter-spacing: -.02em; }
.checklist { list-style: none; padding: 0; margin: 0; display: grid; gap: 14px; }
.checklist li { display: grid; grid-template-columns: 26px 1fr; gap: 12px; font-size: 16px; color: #25355a; }
.checklist li::before { content: ""; width: 22px; height: 22px; border-radius: 50%; margin-top: 1px; background: #dff7ef url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%23109971' stroke-width='3' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='M5 12.5l4.5 4.5L19 7.5'/%3E%3C/svg%3E") center / 13px no-repeat; }
.aud .actions { display: flex; gap: 10px; flex-wrap: wrap; margin-top: auto; }
.btn-outline-dark { border: 1px solid #c7d3ea; color: var(--ink); background: #fff; }
.btn-outline-dark:hover { border-color: var(--ink); }
.file-note { font-size: 13px; color: var(--ink-muted); }
@media (max-width: 1023px) { .audience { grid-template-columns: 1fr; } }
@media (max-width: 599px) { .aud { padding: 24px; } .aud h3 { font-size: 24px; } .aud .actions .btn { width: 100%; } }

/* О проекте */
.about { margin-top: 20px; border-radius: 28px; overflow: hidden; display: grid; grid-template-columns: 1.1fr 1fr; background: linear-gradient(120deg, #0c3d93 0%, #1848c8 55%, #2f6bff 100%); color: #fff; position: relative; }
.about::before { content: ""; position: absolute; inset: 0; background-image: linear-gradient(rgba(255,255,255,.06) 1px, transparent 1px), linear-gradient(90deg, rgba(255,255,255,.06) 1px, transparent 1px); background-size: 44px 44px; mask-image: linear-gradient(90deg, transparent, #000 60%); }
.about-copy { position: relative; padding: 56px; display: flex; flex-direction: column; gap: 22px; }
.about-copy .label { color: #bfe9ff; }
.about-copy p { margin: 0; color: #d6e4ff; font-size: 17px; max-width: 520px; }
.about-logos { display: flex; align-items: center; gap: 22px; margin-top: 8px; flex-wrap: wrap; }
.about-logos .sibur { background: #fff; border-radius: 12px; padding: 12px 16px; }
.about-logos .sibur img { height: 28px; width: auto; }
.about-logos svg { width: 130px; color: #fff; }
.about-nums { position: relative; display: grid; grid-template-columns: 1fr 1fr; align-content: center; gap: 1px; padding: 56px 56px 56px 0; }
.about-nums div { padding: 26px; background: rgba(4, 11, 30, .22); backdrop-filter: blur(6px); }
.about-nums div:first-child { border-radius: 18px 0 0 0; } .about-nums div:nth-child(2) { border-radius: 0 18px 0 0; }
.about-nums div:nth-child(3) { border-radius: 0 0 0 18px; } .about-nums div:last-child { border-radius: 0 0 18px 0; }
.about-nums b { display: block; font-size: 44px; line-height: 1; font-weight: 700; letter-spacing: -.03em; }
.about-nums span { font-size: 14px; color: #cfe0ff; }
@media (max-width: 1023px) { .about { grid-template-columns: 1fr; } .about-nums { padding: 0 24px 32px; } .about-copy { padding: 36px 24px; } }

/* FAQ */
.faq { display: grid; grid-template-columns: .8fr 1.2fr; gap: 48px; }
.faq-list { display: grid; gap: 10px; }
.faq details { background: #fff; border-radius: 18px; padding: 0 24px; box-shadow: 0 1px 0 rgba(11, 22, 51, .06); }
.faq summary { list-style: none; cursor: pointer; padding: 22px 0; font-weight: 600; font-size: 18px; display: flex; justify-content: space-between; gap: 16px; align-items: center; }
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after { content: "+"; flex: none; width: 32px; height: 32px; border-radius: 50%; background: var(--ice-2); display: grid; place-items: center; font-weight: 400; font-size: 22px; transition: transform .25s; }
.faq details[open] summary::after { transform: rotate(45deg); }
.faq details p { margin: 0 0 22px; color: var(--ink-muted); }
@media (max-width: 1023px) { .faq { grid-template-columns: 1fr; gap: 28px; } }

/* ============================================================
   ПОДВАЛ (хром prosv.ru)
   ============================================================ */
.site-footer { background: var(--ice); color: var(--ink); padding: 40px 0 36px; }
.foot-cards { display: grid; grid-template-columns: 1fr 1fr 1.6fr 1fr; gap: 10px; }
.foot-cards > div { background: #fff; border-radius: 16px; padding: 22px 24px; font-size: 15px; }
.foot-cards small { display: block; font-weight: 600; margin-bottom: 6px; font-size: 14px; }
.foot-cards span { color: var(--ink-muted); }
.socials { display: flex; gap: 8px; }
.socials a { width: 40px; height: 40px; border-radius: 50%; border: 1px solid #d5dcea; display: grid; place-items: center; font-weight: 700; font-size: 13px; }
.foot-bottom { display: flex; align-items: center; gap: 32px; margin-top: 28px; font-size: 13px; color: var(--ink-muted); flex-wrap: wrap; }
.foot-bottom svg { width: 110px; color: #2c3e8f; }
.age { margin-left: auto; width: 40px; height: 40px; border-radius: 50%; border: 2px solid var(--ink-muted); display: grid; place-items: center; font-weight: 700; font-size: 13px; color: var(--ink-muted); }
@media (max-width: 1023px) { .foot-cards { grid-template-columns: 1fr 1fr; } }
@media (max-width: 599px) { .foot-cards { grid-template-columns: 1fr; } }

/* ============================================================
   МОДАЛКА ВИДЕО
   ============================================================ */
.modal { position: fixed; inset: 0; z-index: 100; display: none; place-items: center; padding: 24px; background: rgba(2, 6, 18, .88); backdrop-filter: blur(8px); }
.modal.is-open { display: grid; }
.modal-inner { width: min(1200px, 100%); position: relative; }
.modal video { width: 100%; border-radius: 16px; background: #000; aspect-ratio: 16 / 9; }
.modal-close { position: absolute; top: -52px; right: 0; width: 44px; height: 44px; border-radius: 50%; background: rgba(255, 255, 255, .12); font-size: 26px; line-height: 1; }

/* ============================================================
   ВНУТРЕННИЕ СТРАНИЦЫ
   ============================================================ */
.page-top { padding-top: calc(var(--header-h) + 28px); }
.site-header.static { background: #fff; color: var(--ink); box-shadow: 0 1px 0 rgba(11, 22, 51, .08); }
.site-header.static .login { background: #eef1f8; color: #2c4fa8; }
.site-header.static .burger { background: #eef1f8; }
.crumbs { display: flex; gap: 10px; align-items: center; font-size: 14px; color: var(--muted); flex-wrap: wrap; margin-bottom: 28px; }
.crumbs a:hover { color: var(--text); }
.crumbs i { font-style: normal; color: var(--dim); }
.subnav { position: sticky; top: var(--header-h); z-index: 40; background: rgba(4, 11, 30, .82); backdrop-filter: blur(12px); border-bottom: 1px solid var(--line); }
.subnav .container { display: flex; align-items: center; gap: 28px; height: 56px; overflow-x: auto; white-space: nowrap; scrollbar-width: none; }
.subnav .brand { font-weight: 700; display: flex; align-items: center; gap: 10px; }
.subnav .brand::before { content: ""; width: 10px; height: 10px; border-radius: 50%; background: var(--cyan); box-shadow: 0 0 12px var(--cyan); }
.subnav a { font-size: 14px; color: var(--muted); }
.subnav a.is-active, .subnav a:hover { color: var(--text); }
.subnav .spacer { margin-left: auto; }

/* Страница темы */
.topic-hero { position: relative; overflow: hidden; border-radius: 28px; min-height: 520px; display: flex; align-items: flex-end; }
.topic-hero > img { position: absolute; inset: 0; width: 100%; height: 100%; object-fit: cover; }
.topic-hero::after { content: ""; position: absolute; inset: 0; background: linear-gradient(90deg, rgba(4, 11, 30, .96) 0%, rgba(4, 11, 30, .7) 45%, rgba(4, 11, 30, .1) 100%), linear-gradient(0deg, rgba(4, 11, 30, .7), transparent 40%); }
.topic-hero-body { position: relative; z-index: 2; padding: 56px; max-width: 760px; display: flex; flex-direction: column; gap: 20px; }
.topic-hero .meta-row { display: flex; gap: 10px; flex-wrap: wrap; }
.topic-hero .progress-wrap { display: grid; gap: 8px; max-width: 360px; font-size: 14px; color: var(--muted); }
@media (max-width: 767px) { .topic-hero { min-height: 560px; border-radius: 20px; } .topic-hero-body { padding: 24px; } .topic-hero::after { background: linear-gradient(0deg, rgba(4, 11, 30, .98) 45%, rgba(4, 11, 30, .2) 100%); } }

.lesson-list { display: grid; gap: 12px; }
.lesson-row { display: grid; grid-template-columns: 64px 280px 1fr auto; gap: 28px; align-items: center; padding: 16px 28px 16px 16px; transition: border-color .25s, background .25s; }
.lesson-row:hover { border-color: var(--line-strong); background: linear-gradient(180deg, rgba(20, 50, 110, .7), rgba(9, 24, 58, .7)); }
.lesson-row .idx { font-size: 44px; font-weight: 800; letter-spacing: -.04em; color: transparent; -webkit-text-stroke: 1px rgba(79, 216, 255, .6); text-align: center; }
.lesson-thumb { position: relative; aspect-ratio: 16 / 9; border-radius: 12px; overflow: hidden; }
.lesson-thumb img { width: 100%; height: 100%; object-fit: cover; }
.lesson-thumb .time { position: absolute; right: 8px; bottom: 8px; font-family: var(--mono); font-size: 12px; background: rgba(4, 11, 30, .8); padding: 3px 7px; border-radius: 6px; }
.lesson-thumb .pl { position: absolute; left: 50%; top: 50%; transform: translate(-50%, -50%); width: 48px; height: 48px; border-radius: 50%; background: rgba(79, 216, 255, .2); border: 1px solid rgba(79, 216, 255, .7); backdrop-filter: blur(6px); display: grid; place-items: center; opacity: 0; transition: opacity .25s; }
.lesson-thumb .pl svg { width: 16px; height: 16px; margin-left: 3px; }
.lesson-row:hover .pl { opacity: 1; }
.lesson-info { display: grid; gap: 8px; }
.lesson-info h3 { margin: 0; font-size: 23px; font-weight: 600; letter-spacing: -.01em; }
.lesson-info p { margin: 0; color: var(--muted); font-size: 15px; }
.lesson-tags { display: flex; gap: 8px; flex-wrap: wrap; }
.tag { font-size: 12px; font-weight: 500; padding: 4px 10px; border-radius: 999px; background: rgba(79, 216, 255, .1); color: var(--cyan); }
.tag.y { background: rgba(255, 200, 61, .12); color: var(--yellow); }
.tag.g { background: rgba(147, 167, 204, .12); color: var(--muted); }
.lesson-status { display: grid; justify-items: end; gap: 10px; }
.status-done { display: inline-flex; gap: 6px; align-items: center; color: var(--mint); font-size: 14px; font-weight: 500; }
.lesson-row.is-soon { opacity: .55; }
.lesson-row.is-soon .lesson-thumb { background: var(--panel-2); display: grid; place-items: center; color: var(--dim); font-family: var(--mono); font-size: 13px; }
@media (max-width: 1023px) {
  .lesson-row { grid-template-columns: 200px 1fr; padding: 14px; gap: 18px; }
  .lesson-row .idx { display: none; }
  .lesson-status { grid-column: 2; justify-items: start; grid-auto-flow: column; }
}
@media (max-width: 599px) { .lesson-row { grid-template-columns: 1fr; } .lesson-status { grid-column: auto; } .lesson-info h3 { font-size: 20px; } }

.glossary { display: grid; grid-template-columns: repeat(4, 1fr); gap: 16px; }
.term { padding: 26px; display: flex; flex-direction: column; gap: 10px; min-height: 220px; }
.term .viz { font-size: 34px; font-weight: 700; letter-spacing: -.02em; margin-bottom: auto; }
.term .viz .yellow { font-family: "Times New Roman", serif; font-size: .7em; vertical-align: super; }
.term h3 { margin: 0; font-size: 19px; font-weight: 600; }
.term p { margin: 0; font-size: 14px; color: var(--muted); }
@media (max-width: 1023px) { .glossary { grid-template-columns: 1fr 1fr; } }
@media (max-width: 599px) { .glossary { grid-template-columns: 1fr; } .term { min-height: 0; } .term .viz { margin-bottom: 12px; } }

.cta-banner { display: grid; grid-template-columns: 1.2fr 1fr; overflow: hidden; border-radius: 28px; background: radial-gradient(80% 120% at 100% 0%, rgba(47, 107, 255, .45), transparent 60%), var(--panel); border: 1px solid var(--line); }
.cta-banner .copy { padding: 48px; display: flex; flex-direction: column; gap: 18px; justify-content: center; align-items: flex-start; }
.cta-banner .pic { position: relative; min-height: 320px; }
.cta-banner .pic img { position: absolute; inset: 0; width: 100%; height: 100%; object-fit: cover; mask-image: linear-gradient(90deg, transparent 0%, #000 35%); -webkit-mask-image: linear-gradient(90deg, transparent 0%, #000 35%); }
@media (max-width: 767px) { .cta-banner { grid-template-columns: 1fr; } .cta-banner .copy { padding: 28px 24px; } .cta-banner .pic { min-height: 200px; order: -1; } .cta-banner .pic img { mask-image: linear-gradient(0deg, transparent 0%, #000 40%); -webkit-mask-image: linear-gradient(0deg, transparent 0%, #000 40%); } }

.pager { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
.pager a { padding: 26px 28px; display: grid; gap: 6px; }
.pager a:last-child { text-align: right; }
.pager small { color: var(--muted); font-size: 13px; font-family: var(--mono); }
.pager b { font-size: 20px; font-weight: 600; }
.pager .is-soon b { color: var(--dim); }
@media (max-width: 599px) { .pager { grid-template-columns: 1fr; } .pager a:last-child { text-align: left; } }

/* Страница урока */
.lesson-layout { display: grid; grid-template-columns: minmax(0, 1fr) 360px; gap: 28px; align-items: start; }
.player { position: relative; border-radius: 20px; overflow: hidden; background: #000; aspect-ratio: 16 / 9; border: 1px solid var(--line); }
.player video { width: 100%; height: 100%; object-fit: cover; }
.player-overlay { position: absolute; inset: 0; display: grid; place-items: center; cursor: pointer; background: linear-gradient(0deg, rgba(4, 11, 30, .55), rgba(4, 11, 30, .1)); transition: opacity .3s; }
.player.is-playing .player-overlay { opacity: 0; pointer-events: none; }
.player-overlay .big-play { position: static; transform: none; }
.qr-note { display: flex; align-items: center; gap: 12px; padding: 12px 16px; border-radius: 14px; background: rgba(255, 200, 61, .1); border: 1px solid rgba(255, 200, 61, .35); color: #ffe3a1; font-size: 14px; margin-bottom: 18px; }
.qr-note svg { width: 22px; height: 22px; flex: none; color: var(--yellow); }
.lesson-head { display: flex; justify-content: space-between; gap: 24px; align-items: start; margin: 28px 0 8px; flex-wrap: wrap; }
.lesson-head h1 { font-size: clamp(30px, 3.6vw, 46px); line-height: 1.05; letter-spacing: -.025em; margin: 10px 0 0; font-weight: 700; }
.lesson-head .actions { display: flex; gap: 8px; }
.icon-btn { width: 48px; height: 48px; border-radius: 12px; border: 1px solid var(--line); display: grid; place-items: center; color: var(--muted); }
.icon-btn:hover { color: var(--text); border-color: var(--line-strong); }
.icon-btn svg { width: 20px; height: 20px; }
.lesson-meta { display: flex; gap: 20px; color: var(--muted); font-size: 15px; flex-wrap: wrap; margin-bottom: 28px; }
.lesson-meta span { display: inline-flex; gap: 8px; align-items: center; }
.lesson-meta svg { width: 18px; height: 18px; color: var(--cyan); }

.tabs { display: flex; gap: 4px; border-bottom: 1px solid var(--line); margin-bottom: 28px; overflow-x: auto; scrollbar-width: none; }
.tab { padding: 14px 18px; font-size: 16px; font-weight: 500; color: var(--muted); border-bottom: 2px solid transparent; margin-bottom: -1px; white-space: nowrap; }
.tab.is-active { color: var(--text); border-color: var(--cyan); }
.tab-panel { display: none; }
.tab-panel.is-active { display: block; }

.takeaways { display: grid; grid-template-columns: repeat(3, 1fr); gap: 14px; }
.take { padding: 22px; display: grid; gap: 10px; align-content: start; }
.take .viz { font-size: 30px; font-weight: 700; letter-spacing: -.01em; }
.take .viz .v { font-family: "Times New Roman", serif; color: var(--yellow); font-size: .62em; vertical-align: super; margin-right: 2px; }
.take p { margin: 0; font-size: 15px; color: #c4d3ef; }
@media (max-width: 767px) { .takeaways { grid-template-columns: 1fr; } }

.timecodes { display: grid; }
.timecodes button { display: grid; grid-template-columns: 64px 1fr auto; gap: 14px; text-align: left; padding: 16px 4px; border-top: 1px solid var(--line); font-size: 16px; align-items: center; }
.timecodes button:hover { color: var(--cyan); }
.timecodes .t { font-family: var(--mono); color: var(--cyan); font-size: 14px; }
.timecodes .arrow { color: var(--dim); }

.teacher-box { padding: 28px; display: grid; gap: 14px; }
.teacher-box ul { margin: 0; padding-left: 20px; color: #c4d3ef; display: grid; gap: 8px; }

.quiz { padding: 32px; margin-top: 36px; }
.quiz-top { display: flex; justify-content: space-between; align-items: center; gap: 16px; margin-bottom: 18px; flex-wrap: wrap; }
.quiz h3 { margin: 6px 0 0; font-size: 24px; font-weight: 600; }
.quiz-q { font-size: 19px; margin: 0 0 16px; }
.answers { display: grid; grid-template-columns: repeat(3, 1fr); gap: 10px; }
.answer { height: 72px; border-radius: 14px; border: 1px solid var(--line-strong); background: rgba(4, 11, 30, .5); font-size: 26px; font-weight: 700; transition: border-color .2s, background .2s; }
.answer:hover { border-color: var(--cyan); }
.answer.ok { border-color: var(--mint); background: rgba(119, 226, 195, .12); color: var(--mint); }
.answer.bad { border-color: var(--red); background: rgba(255, 77, 94, .1); color: #ff9aa4; }
.quiz-foot { display: flex; justify-content: space-between; align-items: center; gap: 12px; margin-top: 18px; flex-wrap: wrap; }
@media (max-width: 599px) { .quiz { padding: 22px; } .answers { grid-template-columns: 1fr; } .answer { height: 56px; } }

.sidebar { position: sticky; top: calc(var(--header-h) + 76px); display: grid; gap: 16px; }
.playlist { padding: 22px; }
.playlist-head { display: flex; justify-content: space-between; align-items: baseline; margin-bottom: 14px; }
.playlist-head b { font-size: 17px; }
.playlist-head span { font-size: 13px; color: var(--muted); }
.pl-item { display: grid; grid-template-columns: 112px 1fr; gap: 12px; padding: 10px; border-radius: 12px; align-items: center; }
.pl-item:hover { background: rgba(79, 216, 255, .06); }
.pl-item.is-current { background: rgba(79, 216, 255, .1); box-shadow: inset 3px 0 0 var(--cyan); }
.pl-item .th { position: relative; aspect-ratio: 16 / 9; border-radius: 8px; overflow: hidden; background: var(--panel-2); display: grid; place-items: center; color: var(--dim); }
.pl-item .th img { width: 100%; height: 100%; object-fit: cover; }
.pl-item .th small { position: absolute; right: 4px; bottom: 4px; font-family: var(--mono); font-size: 10px; background: rgba(4, 11, 30, .85); padding: 1px 5px; border-radius: 4px; color: #fff; }
.pl-item b { display: block; font-size: 14px; font-weight: 600; line-height: 1.3; }
.pl-item span { font-size: 12px; color: var(--muted); }
.pl-item.is-soon { opacity: .5; }
.next-card { overflow: hidden; }
.next-card img { aspect-ratio: 16 / 9; width: 100%; object-fit: cover; border-radius: var(--radius) var(--radius) 0 0; }
.next-card .b { padding: 18px 22px 22px; display: grid; gap: 12px; }
.next-card small { font-family: var(--mono); color: var(--cyan); font-size: 12px; }
.next-card b { font-size: 19px; }
@media (max-width: 1023px) { .lesson-layout { grid-template-columns: minmax(0, 1fr); } .sidebar { position: static; } }

/* ============================================================
   Переключатель страниц макета (удалить при вёрстке)
   ============================================================ */
.mock-nav { position: fixed; left: 16px; bottom: 16px; z-index: 90; display: flex; gap: 4px; padding: 4px; border-radius: 14px; background: rgba(255, 255, 255, .95); box-shadow: 0 10px 30px rgba(0, 0, 0, .35); font-size: 13px; font-weight: 600; color: var(--ink); }
.mock-nav a { padding: 8px 12px; border-radius: 10px; }
.mock-nav a.is-active { background: var(--ink); color: #fff; }
@media (max-width: 599px) { .mock-nav { left: 50%; transform: translateX(-50%); } }

/* появление при скролле */
.reveal { opacity: 0; transform: translateY(24px); transition: opacity .8s ease, transform .8s ease; }
.reveal.is-in { opacity: 1; transform: none; }
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .reveal { opacity: 1; transform: none; transition: none; }
  .float-tag, .soon-formula::before { animation: none; }
}

/* логотип Просвещения через маску — перекрашивается от currentColor */
.prosv-mark { display: block; aspect-ratio: 157 / 61; background: currentColor; -webkit-mask: url(../assets/logo/prosv.svg) center / contain no-repeat; mask: url(../assets/logo/prosv.svg) center / contain no-repeat; }
.logo-prosv .prosv-mark { width: 118px; }
.cobrand .prosv-mark { width: 104px; color: #fff; }
.about-logos .prosv-mark { width: 140px; color: #fff; }
.foot-bottom .prosv-mark { width: 110px; color: #2c3e8f; }

/* ---------- правки v01.1 ---------- */
/* химические символы: шрифт с различимыми l / I */
.chem, .el-card .sym, .formula-out, .term .viz, .take .viz, .soon-formula, .float-tag b, .answer, .world-body .formula {
  font-family: "IBM Plex Sans", var(--font); letter-spacing: -.01em;
}
.soon-formula span { position: relative; }
.topic.is-soon.is-wide { grid-column: span 6; }
.topic.is-soon.is-wide .topic-cover { aspect-ratio: 16 / 6.2; }
@media (max-width: 1023px) { .topic.is-soon.is-wide { grid-column: span 6; } .topic.is-soon.is-wide .topic-cover { aspect-ratio: 16 / 9; } }
@media (max-width: 767px) { .topic.is-soon.is-wide { grid-column: span 12; } }

/* ведущий: чистый фон лаборатории без второго персонажа */
.host { background: radial-gradient(60% 80% at 75% 45%, #2a6fd8 0%, #0f2f78 38%, #06122e 75%); }
.host-bg { filter: none; transform: none; background:
  linear-gradient(rgba(79, 216, 255, .07) 1px, transparent 1px) 0 0 / 48px 48px,
  linear-gradient(90deg, rgba(79, 216, 255, .07) 1px, transparent 1px) 0 0 / 48px 48px;
  mask-image: radial-gradient(70% 90% at 72% 50%, #000 30%, transparent 80%); -webkit-mask-image: radial-gradient(70% 90% at 72% 50%, #000 30%, transparent 80%); }
.host-bg::after { display: none; }
.host::after { content: ""; position: absolute; left: 50%; bottom: -120px; width: 620px; height: 260px; border-radius: 50%; border: 2px solid rgba(79, 216, 255, .45); box-shadow: 0 0 60px rgba(79, 216, 255, .35), inset 0 0 60px rgba(79, 216, 255, .25); pointer-events: none; }
.host-copy .h2 { font-size: clamp(30px, 3.4vw, 48px); }
@media (min-width: 1024px) { .host { grid-template-columns: 1.05fr .95fr; } }
@media (max-width: 1023px) {
  .host { grid-template-columns: 1fr; }
  .host::after { display: none; }
  .host-img { justify-self: center; padding-top: 24px; }
  .host-img img { height: 360px; }
  .host-copy { padding-top: 8px; }
  .tag-fashion { top: 36px; right: 16px; }
}

/* лента «Химия вокруг»: на десктопе 4 карточки влезают целиком */
@media (min-width: 1024px) { .rail { grid-auto-columns: calc((100% - 48px) / 4); overflow: visible; } }
.world::after { background: linear-gradient(0deg, rgba(4, 11, 30, .98) 20%, rgba(4, 11, 30, .55) 55%, rgba(4, 11, 30, .05) 85%); }
.world-body .formula { font-size: 12px; }
.light.section + .light.section { padding-top: 0; }

/* ============================================================
   v02 — «Химия с ИИ» по ТЗ
   ============================================================ */
.hero-tagline { font-size: clamp(22px, 2.4vw, 32px); font-weight: 600; letter-spacing: -.015em; margin: -6px 0 18px; color: #fff; }
.next-chip { color: #ffe3a1; border-color: rgba(255, 200, 61, .4); background: rgba(255, 200, 61, .08); }
.next-chip b { color: var(--yellow); font-weight: 600; margin: 0 3px; }
.steps-3 { grid-template-columns: repeat(3, 1fr); }
@media (max-width: 1023px) { .steps-3 { grid-template-columns: 1fr; } .steps-3 .step { min-height: 0; } .steps-3 .step .num { margin-bottom: 18px; } }
.chip.ghost { background: transparent; border-style: dashed; color: var(--dim); }

/* список тем с видео */
.theme-list { display: grid; gap: 16px; }
.theme-row { display: grid; grid-template-columns: minmax(0, .9fr) minmax(0, 2fr); gap: 32px; padding: 28px; }
.theme-head { display: flex; flex-direction: column; gap: 12px; align-items: flex-start; }
.theme-n { font-size: 64px; font-weight: 800; line-height: .9; letter-spacing: -.05em; color: transparent; -webkit-text-stroke: 1px rgba(79, 216, 255, .6); }
.theme-meta { display: flex; gap: 8px; flex-wrap: wrap; }
.theme-head h3 { margin: 4px 0 0; font-size: 24px; line-height: 1.2; font-weight: 600; letter-spacing: -.015em; }
.theme-school { margin: 0; font-size: 14px; color: var(--muted); }
.theme-head .go { margin-top: auto; display: inline-flex; align-items: center; gap: 8px; font-weight: 600; font-size: 15px; color: var(--yellow); }
.theme-head .go svg { width: 18px; height: 18px; transition: transform .2s; }
.theme-head .go:hover svg { transform: translateX(4px); }
.theme-videos { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 14px; }
.vcard { display: flex; flex-direction: column; gap: 12px; }
.vcard:hover .vthumb:not(.is-black) img { transform: scale(1.05); }
.vcard:hover b { color: var(--cyan); }
.vcap { display: grid; gap: 6px; }
.vcap small { font-family: var(--mono); font-size: 11px; letter-spacing: .04em; color: var(--cyan); text-transform: uppercase; }
.vcap b { font-size: 15px; line-height: 1.35; font-weight: 600; transition: color .2s; }
.is-future .vcap b { color: #c4d3ef; }
.theme-row.is-compact .vcap b { color: var(--muted); font-weight: 500; }

.vthumb { position: relative; aspect-ratio: 16 / 9; border-radius: 12px; overflow: hidden; background: #000; border: 1px solid var(--line); }
.vthumb img { width: 100%; height: 100%; object-fit: cover; transition: transform .5s; }
.vthumb.is-black { background: #000; border-color: rgba(255, 255, 255, .06); display: grid; place-items: center; }
.vplay { position: absolute; left: 10px; bottom: 10px; width: 32px; height: 32px; border-radius: 50%; display: grid; place-items: center; background: rgba(4, 11, 30, .7); border: 1px solid rgba(79, 216, 255, .7); color: #fff; backdrop-filter: blur(6px); }
.vplay svg { width: 11px; height: 11px; margin-left: 2px; }
.vdur { position: absolute; right: 8px; bottom: 8px; font-family: var(--mono); font-size: 11px; background: rgba(4, 11, 30, .8); padding: 2px 6px; border-radius: 6px; }
.vdate { font-family: var(--mono); font-size: 12px; color: rgba(255, 255, 255, .35); letter-spacing: .04em; }

@media (max-width: 1023px) { .theme-row { grid-template-columns: 1fr; gap: 22px; } .theme-videos { grid-template-columns: repeat(2, minmax(0, 1fr)); } }
@media (max-width: 599px) {
  .theme-row { padding: 20px; }
  .theme-videos { grid-template-columns: none; grid-auto-flow: column; grid-auto-columns: 72%; overflow-x: auto; scroll-snap-type: x mandatory; margin: 0 -20px; padding: 0 20px 6px; }
  .vcard { scroll-snap-align: start; }
  .theme-n { font-size: 48px; }
  .theme-head h3 { font-size: 21px; }
}

/* таймлайн графика */
.timeline { display: grid; grid-template-columns: repeat(7, minmax(0, 1fr)); position: relative; padding-top: 12px; }
.timeline::before { content: ""; position: absolute; left: 0; right: 0; top: 19px; height: 2px; background: linear-gradient(90deg, var(--mint) 0%, var(--mint) var(--tl-done, 30%), rgba(147, 167, 204, .2) var(--tl-done, 30%)); }
.tl-item { position: relative; display: flex; flex-direction: column; gap: 6px; padding: 0 12px 0 0; }
.tl-dot { width: 16px; height: 16px; border-radius: 50%; background: var(--bg); border: 2px solid rgba(147, 167, 204, .45); margin-bottom: 14px; position: relative; z-index: 1; }
.tl-item.is-done .tl-dot { background: var(--mint); border-color: var(--mint); box-shadow: 0 0 14px rgba(119, 226, 195, .7); }
.tl-item.is-next .tl-dot { border-color: var(--yellow); background: var(--yellow); box-shadow: 0 0 0 6px rgba(255, 200, 61, .18), 0 0 18px rgba(255, 200, 61, .7); }
.tl-date { font-family: var(--mono); font-size: 13px; color: var(--cyan); }
.tl-item.is-next .tl-date { color: var(--yellow); }
.tl-item b { font-size: 18px; font-weight: 600; }
.tl-title { font-size: 14px; color: var(--muted); line-height: 1.35; }
.tl-state { font-size: 12px; color: var(--dim); margin-top: 4px; }
.tl-item.is-done .tl-state { color: var(--mint); }
.tl-item.is-next .tl-state { color: var(--yellow); }
.tl-item:hover b { color: var(--cyan); }
@media (max-width: 1023px) {
  .timeline { grid-template-columns: none; grid-auto-flow: column; grid-auto-columns: 180px; overflow-x: auto; padding-bottom: 10px; scrollbar-width: thin; }
  .timeline::before { right: auto; width: calc(180px * 7); }
}

/* авторы */
.authors { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; }
.author { display: flex; gap: 18px; align-items: center; padding: 24px; }
.avatar { flex: none; width: 72px; height: 72px; border-radius: 50%; display: grid; place-items: center; font-weight: 700; font-size: 22px; letter-spacing: -.02em; background: linear-gradient(140deg, #1d4fbf, #0b1d44); border: 1px solid var(--line-strong); color: var(--cyan); }
.avatar-logo { background: #fff; }
.avatar-logo img { width: 54px; height: auto; }
.author b { display: block; font-size: 19px; font-weight: 600; margin-bottom: 4px; }
.author span { font-size: 14px; color: var(--muted); line-height: 1.45; }
.ai-note { margin-top: 16px; display: flex; gap: 20px; align-items: center; padding: 22px 26px; }
.ai-badge { flex: none; width: 52px; height: 52px; border-radius: 14px; display: grid; place-items: center; font-weight: 800; color: var(--bg); background: linear-gradient(140deg, var(--cyan), var(--mint)); }
.ai-note p { margin: 0; color: #c4d3ef; font-size: 16px; }
.ai-note b { color: #fff; }
@media (max-width: 1023px) { .authors { grid-template-columns: 1fr; } }
@media (max-width: 599px) { .ai-note { align-items: flex-start; } }

.world-body .more { font-size: 14px; font-weight: 600; color: var(--yellow); }

/* страница темы */
.topic-hero-void { position: absolute; inset: 0; background: radial-gradient(70% 90% at 80% 30%, #16347a 0%, #07132e 60%, #040b1e 100%); }
.topic-hero-void::after { content: ""; position: absolute; inset: 0; background-image: linear-gradient(rgba(79, 216, 255, .06) 1px, transparent 1px), linear-gradient(90deg, rgba(79, 216, 255, .06) 1px, transparent 1px); background-size: 48px 48px; mask-image: radial-gradient(70% 80% at 80% 40%, #000, transparent); -webkit-mask-image: radial-gradient(70% 80% at 80% 40%, #000, transparent); }
.topic-hero .lead { color: #c4d3ef; }
.topic-title { font-size: clamp(34px, 4.4vw, 60px) !important; }
.btn.is-static { cursor: default; }
.lesson-row .idx { font-size: 34px; }
.lesson-row .vthumb.lesson-thumb { border-radius: 12px; }
.lesson-row .vthumb .vplay { left: 50%; top: 50%; bottom: auto; transform: translate(-50%, -50%); width: 48px; height: 48px; }
.lesson-row.is-pending h3 { color: #c4d3ef; }
.lesson-info p { line-height: 1.5; }

/* страница видео */
.player.is-black { background: #000; border-color: rgba(255, 255, 255, .06); display: grid; place-items: center; }
.black-cap { font-family: var(--mono); font-size: 13px; letter-spacing: .06em; color: rgba(255, 255, 255, .35); }
.lesson-head h1 { font-size: clamp(26px, 3vw, 40px) !important; }
.lesson-theme { margin: 10px 0 0; font-size: 15px; }
.lesson-theme a { color: var(--muted); border-bottom: 1px solid var(--line-strong); }
.lesson-theme a:hover { color: var(--text); }
.lesson-about { padding: 28px; display: grid; gap: 12px; }
.lesson-about p { margin: 0; font-size: 19px; line-height: 1.55; color: #dbe6fb; }
.lesson-chapters { margin-top: 28px; display: grid; gap: 12px; }
.pl-item .th.is-black { background: #000; }
.pl-item.is-pending b { color: #c4d3ef; }
.next-black { aspect-ratio: 16 / 9; background: #000; border-radius: var(--radius) var(--radius) 0 0; }
.theme-soon-note { grid-column: 1 / -1; margin: 0; font-size: 15px; color: var(--muted); }
.theme-row.is-compact { padding-top: 22px; padding-bottom: 22px; }
.theme-row.is-compact .theme-n { font-size: 48px; }
.theme-row.is-compact .vthumb { aspect-ratio: 16 / 7; }
.tag-fashion { top: auto; bottom: 26%; right: 30%; }
@media (max-width: 1023px) { .tag-fashion { bottom: auto; top: 300px; right: 16px; } }
@media (max-width: 599px) { .theme-videos { scrollbar-width: none; } .theme-videos::-webkit-scrollbar { display: none; } .theme-soon-note { display: none; } }

/* ============================================================
   v03 — обозреватель курса на главной (плеер + темы + тайм-коды)
   ============================================================ */
.cx { display: grid; gap: 20px; }
.cx-tabs { display: grid; grid-template-columns: repeat(7, minmax(0, 1fr)); gap: 8px; }
.cx-tab {
  text-align: left; display: grid; gap: 6px; align-content: start; padding: 14px 14px 12px; border-radius: 14px;
  border: 1px solid var(--line); background: rgba(11, 29, 68, .45); transition: border-color .2s, background .2s, transform .2s;
}
.cx-tab:hover { border-color: var(--line-strong); transform: translateY(-2px); }
.cx-tab-n { font-size: 26px; font-weight: 800; line-height: 1; letter-spacing: -.04em; color: transparent; -webkit-text-stroke: 1px rgba(79, 216, 255, .55); }
.cx-tab-t { font-size: 13px; font-weight: 600; line-height: 1.25; color: var(--muted); min-height: 2.5em; }
.cx-tab-d { display: inline-flex; align-items: center; gap: 6px; font-family: var(--mono); font-size: 11px; color: var(--dim); }
.cx-tab-d i { width: 6px; height: 6px; border-radius: 50%; background: var(--dim); }
.cx-tab.is-out .cx-tab-d { color: var(--mint); }
.cx-tab.is-out .cx-tab-d i { background: var(--mint); box-shadow: 0 0 8px var(--mint); }
.cx-tab.is-active { background: linear-gradient(160deg, #1b4bb8 0%, #0e2658 100%); border-color: var(--cyan); box-shadow: 0 0 0 1px rgba(79, 216, 255, .35), 0 12px 40px -18px rgba(79, 216, 255, .8); }
.cx-tab.is-active .cx-tab-n { color: #fff; -webkit-text-stroke: 0; }
.cx-tab.is-active .cx-tab-t { color: #fff; }

.cx-body { display: grid; grid-template-columns: minmax(0, 1.65fr) minmax(0, 1fr); gap: 20px; align-items: start; }
.cx-player { position: relative; aspect-ratio: 16 / 9; border-radius: 20px; overflow: hidden; background: #000; border: 1px solid var(--line); }
.cx-player video { width: 100%; height: 100%; object-fit: cover; }
.cx-player.is-black { display: grid; place-items: center; border-color: rgba(255, 255, 255, .06); }
.cx-play { position: absolute; inset: 0; display: grid; place-items: center; background: linear-gradient(0deg, rgba(4, 11, 30, .45), rgba(4, 11, 30, .05)); transition: opacity .3s; }
.cx-play .big-play { position: static; transform: none; }
.cx-play:hover .big-play { transform: scale(1.08); }
.cx-badge { position: absolute; left: 16px; top: 16px; font-family: var(--mono); font-size: 12px; padding: 6px 10px; border-radius: 8px; background: rgba(4, 11, 30, .7); border: 1px solid var(--line); backdrop-filter: blur(6px); transition: opacity .3s; }
.cx-player.is-playing .cx-play, .cx-player.is-playing .cx-badge { opacity: 0; pointer-events: none; }

.cx-info { padding: 24px 4px 0; display: grid; gap: 10px; }
.cx-info h3 { margin: 4px 0 0; font-size: clamp(24px, 2.4vw, 32px); line-height: 1.15; font-weight: 700; letter-spacing: -.02em; }
.cx-q { margin: 6px 0 0; font-size: 19px; font-weight: 600; color: var(--yellow); line-height: 1.4; }
.cx-a { margin: 0; font-size: 17px; color: #c4d3ef; line-height: 1.55; max-width: 720px; }
.cx-actions { display: flex; align-items: center; gap: 20px; margin-top: 8px; flex-wrap: wrap; }
.cx-more { font-size: 15px; font-weight: 600; color: var(--cyan); }

.cx-list { padding: 18px; display: grid; gap: 6px; }
.cx-list-head { display: grid; gap: 10px; padding: 4px 6px 12px; border-bottom: 1px solid var(--line); margin-bottom: 6px; }
.cx-list-head b { font-size: 17px; line-height: 1.3; }
.cx-list-head .chip { justify-self: start; height: 28px; font-size: 12px; }
.cx-item { border-radius: 14px; transition: background .2s; }
.cx-item.is-current { background: rgba(79, 216, 255, .08); box-shadow: inset 3px 0 0 var(--cyan); }
.cx-row { width: 100%; display: grid; grid-template-columns: 104px 1fr; gap: 12px; align-items: center; padding: 10px; text-align: left; border-radius: 14px; }
.cx-row:hover { background: rgba(79, 216, 255, .05); }
.cx-th { position: relative; aspect-ratio: 16 / 9; border-radius: 8px; overflow: hidden; background: var(--panel-2); }
.cx-th img { width: 100%; height: 100%; object-fit: cover; }
.cx-th.is-black { background: #000; }
.cx-rt { display: grid; gap: 4px; }
.cx-rt small { font-family: var(--mono); font-size: 10.5px; color: var(--cyan); letter-spacing: .02em; }
.cx-rt b { font-size: 14px; line-height: 1.3; font-weight: 600; }
.cx-item.is-pending .cx-rt b { color: var(--muted); font-weight: 500; }
.cx-item.is-pending .cx-rt small { color: var(--dim); }

/* «эквалайзер» на текущем видео */
.eq { position: absolute; inset: 0; display: flex; align-items: flex-end; justify-content: center; gap: 3px; padding-bottom: 8px; background: rgba(4, 11, 30, .45); }
.eq i { width: 3px; height: 10px; border-radius: 2px; background: var(--cyan); animation: eq 1s ease-in-out infinite; }
.eq i:nth-child(2) { animation-delay: -.3s; } .eq i:nth-child(3) { animation-delay: -.6s; }
@keyframes eq { 0%, 100% { height: 5px; } 50% { height: 16px; } }

/* тайм-коды внутри раскрытого видео */
.cx-chapters { display: grid; padding: 0 10px 12px 126px; }
.cx-chapters button { display: grid; grid-template-columns: 44px 1fr; gap: 8px; text-align: left; padding: 7px 8px; border-radius: 8px; font-size: 13px; color: #c4d3ef; line-height: 1.35; }
.cx-chapters button:hover { background: rgba(79, 216, 255, .08); color: #fff; }
.cx-chapters .t { font-family: var(--mono); font-size: 12px; color: var(--cyan); }
.cx-chapters button.is-now { background: rgba(255, 200, 61, .1); color: #fff; }
.cx-chapters button.is-now .t { color: var(--yellow); }

@media (max-width: 1279px) { .cx-tab-t { display: none; } .cx-tab { padding: 12px; } }
@media (max-width: 1023px) {
  .cx-tabs { grid-template-columns: none; grid-auto-flow: column; grid-auto-columns: 170px; overflow-x: auto; scrollbar-width: none; margin: 0 -32px; padding: 2px 32px 6px; }
  .cx-tabs::-webkit-scrollbar { display: none; }
  .cx-tab-t { display: block; }
  .cx-body { grid-template-columns: 1fr; }
  .cx-chapters { padding-left: 10px; }
}
@media (max-width: 767px) { .cx-tabs { margin: 0 -16px; padding: 2px 16px 6px; grid-auto-columns: 150px; } .cx-list { padding: 10px; } .cx-row { grid-template-columns: 88px 1fr; } }

/* v03.1 — тизер-подача внутри обозревателя */
.cx-head { display: grid; gap: 16px; padding-top: 12px; max-width: 980px; }
.cx-title { margin: 0; font-size: clamp(34px, 4.6vw, 64px); line-height: 1.04; letter-spacing: -.03em; font-weight: 700; }
.cx-head .lead { max-width: 640px; }
.cx-head.is-anim > * { animation: cxIn .5s ease both; }
.cx-head.is-anim > *:nth-child(2) { animation-delay: .05s; } .cx-head.is-anim > *:nth-child(3) { animation-delay: .1s; }
@keyframes cxIn { from { opacity: 0; transform: translateY(10px); } to { opacity: 1; transform: none; } }

.cx-body { grid-template-columns: minmax(0, 1.6fr) minmax(0, 1fr); align-items: stretch; margin-top: 8px; }
.cx-player.player-card { border: 1px solid var(--line); }
.cx-player.is-black .player-cap { position: absolute; left: 28px; right: 28px; bottom: 24px; }
.cx-player.is-black .player-cap h3 { color: rgba(255, 255, 255, .55); }
.cx-player.is-black .black-cap { position: absolute; top: 50%; left: 50%; transform: translate(-50%, -50%); }
.cx-player.is-playing video { width: 100%; height: 100%; object-fit: contain; background: #000; }

.cx-list { padding: 28px; display: flex; flex-direction: column; gap: 0; }
.cx-list-title { margin: 10px 0 16px; font-size: 20px; line-height: 1.25; font-weight: 600; }
.cx-chapters { display: grid; padding: 0; margin-bottom: 18px; }
.cx-chapters button { grid-template-columns: 56px 1fr; gap: 12px; padding: 11px 6px; border-radius: 0; border-top: 1px solid var(--line); font-size: 15px; color: var(--text); }
.cx-chapters button:hover { background: rgba(79, 216, 255, .05); color: var(--cyan); }
.cx-chapters .t { font-size: 13px; }
.cx-chapters button.is-now { background: rgba(255, 200, 61, .08); }
.cx-sub { display: grid; gap: 4px; }
.cx-sub-h { font-family: var(--mono); font-size: 11px; letter-spacing: .12em; text-transform: uppercase; color: var(--dim); padding: 6px 0 4px; }
.cx-row { grid-template-columns: 76px 1fr; padding: 8px; gap: 12px; }
.cx-row.is-current { background: rgba(79, 216, 255, .1); box-shadow: inset 3px 0 0 var(--cyan); }
.cx-row .cx-rt b { font-size: 13px; }
.cx-row.is-pending .cx-rt b { color: var(--muted); font-weight: 500; }
.cx-row.is-pending .cx-rt small { color: var(--dim); }
.cx-open { margin-top: auto; }
.cx-list > .cx-open { margin-top: 18px; }
@media (max-width: 1023px) { .cx-body { grid-template-columns: 1fr; } .cx-list { padding: 20px; } }
@media (max-width: 767px) { .cx-player .player-cap h3 { font-size: 18px; } .cx-player.is-black .player-cap { left: 16px; right: 16px; bottom: 14px; } }
.cx-body { align-items: start; }
.cx-player { width: 100%; align-self: start; }
@media (min-width: 1024px) { .cx-player { position: sticky; top: calc(var(--header-h) + 20px); } }
.cx-title { font-size: clamp(30px, 3.6vw, 52px); max-width: 1000px; }

/* v03.2 — тайм-коды под видео */
.cx-stage { display: grid; gap: 14px; min-width: 0; }
@media (min-width: 1024px) { .cx-player { position: relative; top: auto; } }
.cx-toc { padding: 18px 20px 14px; border-radius: 18px; border: 1px solid var(--line); background: linear-gradient(180deg, rgba(15, 38, 87, .55), rgba(7, 19, 46, .55)); }
.cx-toc-head { display: flex; justify-content: space-between; align-items: baseline; gap: 12px; margin-bottom: 8px; }
.cx-toc-hint { font-size: 12px; color: var(--dim); }
.cx-toc .cx-chapters { grid-template-columns: 1fr 1fr; column-gap: 28px; margin: 0; }
.cx-toc .cx-chapters button { border-top: 1px solid var(--line); padding: 10px 6px; font-size: 14px; }
.cx-status { justify-self: start; align-self: flex-start; height: 28px; font-size: 12px; margin: -4px 0 14px; }
.cx-list { padding: 24px; }
@media (max-width: 767px) { .cx-toc .cx-chapters { grid-template-columns: 1fr; } .cx-toc-hint { display: none; } }
@media (min-width: 768px) { .cx-toc .cx-chapters { grid-auto-flow: column; grid-template-rows: repeat(var(--rows), auto); } }

/* v03.3 — текст первого экрана выше, по оптическому центру */
.hero { align-items: center; padding: calc(var(--header-h) + 24px) 0 12vh; }
.hero .h1 { margin-bottom: 18px; }
.hero-tagline { line-height: 1.2; margin: 0 0 22px; }
.hero .lead { margin-bottom: 32px; }
@media (max-width: 1023px) { .hero { align-items: flex-end; padding-bottom: 40px; } }
/* v03.4 — первый экран ниже, карточки «Когда пригодится» подтянуты */
.hero { min-height: min(86svh, 900px); padding-bottom: 7vh; }
.qr-strip { padding-top: 0; margin-top: -32px; position: relative; z-index: 3; }
@media (max-width: 1023px) { .hero { min-height: 92svh; } .qr-strip { margin-top: 8px; } }
#courseExplorer, #topics { scroll-margin-top: calc(var(--header-h) + 20px); }

/* v03.5 — тренажёр по открытой теме: вопросы с вариантами и заглушка */
.trainer-intro .h2 { font-size: clamp(30px, 3.4vw, 48px); }
.trainer-intro .levels span:empty { display: none; }
.tq { margin: 4px 0 0; font-size: clamp(20px, 1.9vw, 26px); font-weight: 600; line-height: 1.3; letter-spacing: -.01em; }
.tanswers { display: grid; gap: 10px; }
.tanswer { display: grid; grid-template-columns: 36px 1fr; gap: 14px; align-items: center; text-align: left; padding: 14px 16px; border-radius: 14px; border: 1px solid var(--line-strong); background: rgba(4, 11, 30, .5); font-size: 17px; font-weight: 500; transition: border-color .2s, background .2s; }
.tanswer i { font-style: normal; width: 36px; height: 36px; border-radius: 10px; display: grid; place-items: center; font-family: var(--mono); font-size: 14px; background: rgba(79, 216, 255, .1); color: var(--cyan); }
.tanswer:hover { border-color: var(--cyan); }
.tanswer.ok { border-color: var(--mint); background: rgba(119, 226, 195, .1); }
.tanswer.ok i { background: var(--mint); color: var(--bg); }
.tanswer.bad { border-color: var(--red); background: rgba(255, 77, 94, .08); }
.tanswer.bad i { background: var(--red); color: #fff; }
.quiz-count { font-family: var(--mono); font-size: 13px; color: var(--muted); }
.game.is-empty { display: grid; place-items: center; min-height: 360px; background: #000; border-color: rgba(255, 255, 255, .06); }
.game.is-empty::before, .game.is-empty::after { display: none; }
.empty-in { display: grid; justify-items: center; gap: 14px; text-align: center; padding: 24px; }
.empty-ic { font-size: 72px; font-weight: 800; line-height: 1; letter-spacing: -.05em; color: transparent; -webkit-text-stroke: 1px rgba(79, 216, 255, .45); }
.empty-in p { margin: 0; color: var(--muted); font-size: 15px; }
.empty-actions { display: flex; gap: 8px; flex-wrap: wrap; justify-content: center; }

/* v03.6 — авторы в первом экране (на месте плашки с цифрами) */
.hero-authors { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; margin-top: 56px; padding-top: 22px; border-top: 1px solid var(--line); }
.ha { display: flex; gap: 14px; align-items: center; }
.ha-av { flex: none; width: 48px; height: 48px; border-radius: 50%; display: grid; place-items: center; font-weight: 700; font-size: 15px; color: var(--cyan); background: linear-gradient(140deg, #1d4fbf, #0b1d44); border: 1px solid var(--line-strong); }
.ha-logo { background: #fff; }
.ha-logo img { width: 36px; height: auto; }
.ha b { display: block; font-size: 17px; font-weight: 600; line-height: 1.25; }
.ha span:not(.ha-av) { display: block; font-size: 13px; color: var(--muted); line-height: 1.4; margin-top: 2px; }
.hero { padding-bottom: 5vh; }
@media (max-width: 1023px) { .hero-authors { grid-template-columns: 1fr; gap: 14px; margin-top: 32px; } }

/* ============================================================
   Тёмная тема: блоки, добавленные в v05–v06
   (цвета фирменной гаммы СИБУРа лежат в sibur.css и включаются переключателем)
   ============================================================ */
/* приветствие спикера */
.greet { padding: 44px 0 8px; }
.greet-row { display: grid; grid-template-columns: auto auto; justify-content: center; align-items: center; gap: 32px; }
.greet-circle { position: relative; width: 320px; height: 320px; flex: none; }
.greet-circle video { width: 100%; height: 100%; object-fit: cover; border-radius: 50%; background: #000; }
.greet-ring { position: absolute; inset: -10px; width: calc(100% + 20px); height: calc(100% + 20px); transform: rotate(-90deg); pointer-events: none; }
.greet-ring circle { fill: none; stroke: rgba(79, 216, 255, .18); stroke-width: 2; }
.greet-ring .greet-progress { stroke: var(--cyan); stroke-linecap: round; stroke-dasharray: 301.6; stroke-dashoffset: 301.6; transition: stroke-dashoffset .25s linear; }
.greet-sound { position: absolute; right: 8px; bottom: 8px; width: 46px; height: 46px; border-radius: 50%; display: grid; place-items: center; background: var(--panel-2); color: #fff; box-shadow: 0 8px 20px -8px rgba(0, 0, 0, .8); }
.greet-sound svg { width: 20px; height: 20px; }
.greet-sound .ic-on { display: none; }
.greet-circle.is-loud .greet-sound .ic-on { display: block; }
.greet-circle.is-loud .greet-sound .ic-off { display: none; }

/* чат как в телеграме */
.tg { width: 100%; max-width: 560px; border-radius: 20px; overflow: hidden; background: var(--panel); border: 1px solid var(--line); box-shadow: 0 24px 50px -30px rgba(0, 0, 0, .8); }
.tg-head { display: flex; align-items: center; gap: 12px; padding: 12px 16px; background: var(--panel-2); border-bottom: 1px solid var(--line); }
.tg-ava { width: 42px; height: 42px; border-radius: 50%; overflow: hidden; flex: none; background: var(--panel); }
.tg-ava img { width: 100%; height: 100%; object-fit: cover; object-position: 50% 22%; }
.tg-who { display: grid; gap: 1px; min-width: 0; }
.tg-who b { font-size: 16px; line-height: 1.2; }
.tg-who span { font-size: 13px; color: var(--muted); }
.tg-who span.is-typing { color: var(--cyan); }
.tg-who span i { display: inline-block; width: 3px; height: 3px; border-radius: 50%; background: currentColor; margin-left: 2px; vertical-align: middle; animation: tgdot 1.3s infinite; }
.tg-who span i:nth-child(2) { animation-delay: .18s; } .tg-who span i:nth-child(3) { animation-delay: .36s; }
@keyframes tgdot { 0%, 60%, 100% { opacity: .25; } 30% { opacity: 1; } }
.tg-lock { margin-left: auto; font-family: var(--mono); font-size: 10px; letter-spacing: .14em; color: var(--cyan); border: 1px solid var(--line-strong); border-radius: 6px; padding: 3px 7px; }
.tg-body { padding: 16px 16px 20px; display: grid; gap: 8px; justify-items: start; height: 320px; overflow-y: auto; scroll-behavior: smooth; background: var(--bg-2); scrollbar-width: thin; scrollbar-color: rgba(147, 167, 204, .3) transparent; }
.tg-msg { position: relative; max-width: 86%; background: var(--panel-2); color: var(--text); border-radius: 14px 14px 14px 4px; padding: 8px 60px 8px 13px; font-size: 16px; line-height: 1.4; animation: tgIn .28s ease both; }
.tg-msg p { margin: 0; }
.tg-msg time { position: absolute; right: 12px; bottom: 7px; font-size: 11px; color: var(--dim); }
.tg-msg:last-child { background: rgba(79, 216, 255, .16); }
@keyframes tgIn { from { opacity: 0; transform: translateY(6px) scale(.98); } to { opacity: 1; transform: none; } }
.tg-msg.tg-typing { padding: 12px 16px; display: flex; gap: 5px; background: var(--panel-2); }
.tg-msg.tg-typing i { width: 7px; height: 7px; border-radius: 50%; background: rgba(147, 167, 204, .5); animation: tgdot 1.2s infinite; }
.tg-msg.tg-typing i:nth-child(2) { animation-delay: .18s; } .tg-msg.tg-typing i:nth-child(3) { animation-delay: .36s; }

/* авторы в первом экране */
.hero-authors { display: grid; grid-template-columns: repeat(3, 1fr); gap: 28px; margin-top: 44px; padding-top: 26px; border-top: 1px solid var(--line); }
.ha { display: flex; gap: 16px; align-items: center; }
.ha-av { flex: none; width: 62px; height: 62px; border-radius: 50%; display: grid; place-items: center; font-weight: 700; font-size: 18px; color: var(--cyan); background: linear-gradient(140deg, #1d4fbf, #0b1d44); border: 1px solid var(--line-strong); }
.ha-logo { background: #fff; }
.ha-logo img { width: 46px; height: auto; }
.ha b { display: block; font-size: 20px; font-weight: 600; line-height: 1.2; }
.ha span:not(.ha-av) { display: block; font-size: 15.5px; color: var(--muted); line-height: 1.4; margin-top: 4px; }

/* «Выбирай тему» */
.cx-pick { margin-bottom: 22px; }
.cx-pick-title { font-size: clamp(26px, 3vw, 40px); margin: 0; }

/* заставка невышедшей темы */
.black-cap.big { font-family: var(--font); font-size: clamp(20px, 2.2vw, 30px); font-weight: 600; color: rgba(255, 255, 255, .85); text-align: center; line-height: 1.3; padding: 0 24px; }
.cx.is-soon-theme .cx-body { grid-template-columns: 1fr; }
.cx.is-soon-theme .cx-list, .cx.is-soon-theme .cx-toc { display: none; }

/* карточки «когда пригодится» крупнее */
.steps-3 { grid-template-columns: repeat(3, 1fr); }
.steps-3 .step { padding: 32px; }
.steps-3 .step h3 { font-size: clamp(24px, 2.2vw, 30px); line-height: 1.15; letter-spacing: -.02em; margin-bottom: 10px; color: var(--cyan); }
.steps-3 .step p { font-size: 16px; }
.steps-3 .step .ic { width: 58px; height: 58px; }

/* тренажёры */
.sims { padding-top: 0; }
.sim-cards { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; }
.sim-card { position: relative; border-radius: 24px; overflow: hidden; background: var(--panel); border: 1px solid var(--line); cursor: pointer; display: grid; grid-template-rows: auto 1fr; transition: transform .25s, border-color .25s; }
.sim-card:hover { transform: translateY(-3px); border-color: var(--line-strong); }
.sim-pic { aspect-ratio: 16 / 9; overflow: hidden; }
.sim-pic img { width: 100%; height: 100%; object-fit: cover; transition: transform .5s; }
.sim-card:hover .sim-pic img { transform: scale(1.04); }
.sim-body { padding: 26px 28px 30px; display: flex; flex-direction: column; gap: 10px; }
.sim-body h3 { margin: 0; font-size: clamp(19px, 1.7vw, 23px); line-height: 1.25; font-weight: 600; }
.sim-body p { margin: 0 0 4px; font-size: 15px; color: var(--cyan); }
.sim-body .btn { margin-top: auto; align-self: start; }
.sim-frame { grid-column: 1 / -1; border-radius: 24px; overflow: hidden; border: 1px solid var(--line); background: #0b1620; }
.sim-frame-head { display: flex; align-items: center; justify-content: space-between; gap: 16px; padding: 14px 20px; background: var(--panel-2); }
.sim-frame-head b { font-size: 16px; font-weight: 600; }
.sim-frame-head button { color: var(--cyan); font-size: 14px; }
.sim-frame iframe { width: 100%; height: 720px; border: 0; display: block; background: #fff; }

/* мини-тренажёр: вопросы с вариантами */
.tq { margin: 4px 0 0; font-size: clamp(20px, 1.9vw, 26px); font-weight: 600; line-height: 1.3; }
.tanswers { display: grid; gap: 10px; }
.tanswer { display: grid; grid-template-columns: 36px 1fr; gap: 14px; align-items: center; text-align: left; padding: 14px 16px; border-radius: 14px; border: 1px solid var(--line-strong); background: rgba(4, 11, 30, .5); font-size: 17px; font-weight: 500; transition: border-color .2s, background .2s; }
.tanswer i { font-style: normal; width: 36px; height: 36px; border-radius: 10px; display: grid; place-items: center; font-family: var(--mono); font-size: 14px; background: rgba(79, 216, 255, .1); color: var(--cyan); }
.tanswer:hover { border-color: var(--cyan); }
.tanswer.ok { border-color: var(--mint); background: rgba(119, 226, 195, .12); }
.tanswer.ok i { background: var(--mint); color: var(--bg); }
.tanswer.bad { border-color: var(--red); background: rgba(255, 77, 94, .1); }
.tanswer.bad i { background: var(--red); color: #fff; }
.quiz-count { font-family: var(--mono); font-size: 13px; color: var(--muted); }
.game.is-empty { display: grid; place-items: center; min-height: 360px; }
.empty-in { display: grid; justify-items: center; gap: 14px; text-align: center; padding: 24px; }
.empty-in p { margin: 0; color: var(--muted); font-size: 15px; }
.empty-actions { display: flex; gap: 8px; flex-wrap: wrap; justify-content: center; }

@media (max-width: 1023px) { .sim-cards { grid-template-columns: 1fr; } .sim-frame iframe { height: 560px; } .steps-3 { grid-template-columns: 1fr; } }
@media (max-width: 767px) {
  .greet { padding: 28px 0 4px; }
  .greet-row { grid-template-columns: 1fr; justify-items: center; gap: 20px; }
  .greet-circle { width: 220px; height: 220px; }
  .tg { max-width: 100%; }
  .tg-body { height: 260px; }
  .hero-authors { grid-template-columns: 1fr; gap: 16px; margin-top: 28px; }
}

/* временная кнопка переключения палитры (удалить при вёрстке) */
.theme-switch { position: fixed; right: 20px; bottom: 20px; z-index: 95; display: inline-flex; align-items: center; gap: 10px;
  height: 46px; padding: 0 18px 0 14px; border-radius: 999px; font-size: 14px; font-weight: 600;
  background: #fff; color: #0b1633; box-shadow: 0 10px 30px rgba(0, 0, 0, .35); }
.theme-switch .ts-dot { width: 16px; height: 16px; border-radius: 50%; background: linear-gradient(135deg, #008c95 50%, #77e2c3 50%); }
.theme-switch.is-dark { background: #0b1d44; color: #eaf2ff; box-shadow: 0 10px 30px rgba(0, 0, 0, .6); }
.theme-switch.is-dark .ts-dot { background: linear-gradient(135deg, #2f6bff 50%, #4fd8ff 50%); }
@media (max-width: 599px) { .theme-switch { right: 12px; bottom: 12px; height: 40px; font-size: 13px; } }
/* правки тёмной темы */
.tg-body { align-content: start; }
.qr-strip { margin-top: 24px; padding-top: 0; }
.greet { padding-top: 56px; }
/* авторы: 4 карточки, по две в двух колонках */
.hero-authors { grid-template-columns: 1fr 1fr; gap: 18px 40px; margin-top: 34px; padding-top: 22px; }
.ha { align-items: flex-start; gap: 14px; }
.ha-av { width: 54px; height: 54px; font-size: 16px; }
.ha-logo img { width: 40px; }
.ha b { font-size: 18px; }
.ha span:not(.ha-av) { font-size: 14px; line-height: 1.35; margin-top: 3px; }
@media (max-width: 1023px) { .hero-authors { grid-template-columns: 1fr; gap: 14px; } }
/* авторы: тёмная подложка, чтобы текст читался поверх видео */
.hero-authors { background: rgba(4, 11, 30, .55); backdrop-filter: blur(6px); border: 1px solid rgba(255, 255, 255, .08); border-radius: 22px; padding: 22px 26px; margin-top: 30px; }
.ha span:not(.ha-av) { color: rgba(255, 255, 255, .8); }
/* превью тренажёров: показываем аппарат целиком, без обрезки */
.sim-pic { background: var(--panel-2); display: grid; place-items: center; }
.sim-pic img { object-fit: contain; }

/* ============================================================
   Мобильная версия (до 767px)
   ============================================================ */
@media (max-width: 767px) {
  /* первый экран */
  .hero { min-height: auto; padding-top: calc(var(--header-h) + 36px); padding-bottom: 28px; }
  .hero .h1 { font-size: 44px; margin-bottom: 12px; }
  .hero-tagline { font-size: 22px; margin-bottom: 14px; }
  .hero .lead { font-size: 16px; margin-bottom: 22px; }
  .hero-actions .btn { width: 100%; }
  /* авторы: одна колонка, компактно */
  .hero-authors { grid-template-columns: 1fr !important; gap: 14px; padding: 16px; margin-top: 24px; border-radius: 18px; }
  .ha { gap: 12px; }
  .ha-av { width: 44px; height: 44px; font-size: 14px; }
  .ha-logo img { width: 32px; }
  .ha b { font-size: 16px; }
  .ha span:not(.ha-av) { font-size: 13px; line-height: 1.35; }
  /* приветствие */
  .greet { padding: 32px 0 0; }
  .greet-row { gap: 18px; }
  .greet-circle { width: 200px; height: 200px; }
  .greet-sound { width: 40px; height: 40px; right: 2px; bottom: 2px; }
  .tg-body { height: 210px; padding: 12px; }
  .tg-msg { font-size: 15px; max-width: 92%; }
  .tg-head { padding: 10px 12px; }
  .tg-ava { width: 36px; height: 36px; }
  .tg-who b { font-size: 15px; }
  /* карточки «когда пригодится» */
  .qr-strip { margin-top: 20px !important; }
  .steps-3 { gap: 12px; }
  .steps-3 .step { padding: 20px 20px 22px; min-height: 0; display: grid; grid-template-columns: 44px 1fr; column-gap: 14px; align-items: start; }
  .steps-3 .step .ic { width: 44px; height: 44px; margin: 0; grid-row: span 2; }
  .steps-3 .step .ic svg { width: 22px; height: 22px; }
  .steps-3 .step h3 { font-size: 20px; margin: 0 0 6px; }
  .steps-3 .step p { font-size: 14.5px; }
  /* темы */
  #topics { padding-top: 48px; padding-bottom: 40px; }
  .cx-pick-title { font-size: 26px; }
  .cx-tabs { grid-auto-columns: 132px; gap: 8px; }
  .cx-tab { padding: 12px; }
  .cx-tab-n { font-size: 26px; }
  .cx-tab-t { font-size: 13px; min-height: 0; }
  .cx-title { font-size: 24px !important; }
  .cx-head .lead { font-size: 15px; }
  .cx-player .player-cap h3 { font-size: 17px; }
  .cx-player .player-cap .label { font-size: 10px; }
  .cx-player .time { display: none; }
  .cx-toc { padding: 14px; }
  .cx-toc .cx-chapters button { font-size: 13.5px; padding: 9px 4px; grid-template-columns: 44px 1fr; }
  .cx-list { padding: 16px; }
  .cx-list-title { font-size: 17px; }
  .black-cap.big { font-size: 17px; }
  /* тренажёр */
  #trainer { padding-bottom: 48px; }
  #trainer .section-head { margin-bottom: 18px; }
  .trainer { gap: 12px; }
  .trainer-intro { padding: 22px; gap: 10px; }
  .trainer-intro .h2 { font-size: 28px; }
  .trainer-intro .lead { font-size: 15px; }
  .levels { margin-top: 10px; }
  .game { padding: 20px; gap: 16px; }
  .tq { font-size: 18px; }
  .tanswer { font-size: 15px; padding: 11px 12px; grid-template-columns: 30px 1fr; gap: 10px; }
  .tanswer i { width: 30px; height: 30px; }
  .el-card { width: 84px; height: 96px; }
  .el-card .sym { font-size: 38px; }
  .formula-out { font-size: 40px; padding: 12px; }
  .game.is-empty { min-height: 220px; }
  /* тренажёры-симуляторы */
  .sim-body { padding: 18px 20px 22px; }
  .sim-body h3 { font-size: 18px; }
  .sim-frame iframe { height: 520px; }
  /* заголовки секций */
  .h2 { font-size: 30px; }
  .section { padding: 56px 0; }
  .faq summary { font-size: 16px; padding: 16px 0; }
}
@media (max-width: 767px) { #sims { padding-bottom: 40px; } #faq { padding-top: 40px; } }

/* ============================================================
   Исправления по QA мобильной версии
   ============================================================ */
/* якоря и прокрутка не уходят под шапку */
html { scroll-padding-top: calc(var(--header-h) + 12px); }
#cxPlayer, #cxHead, .sim-frame { scroll-margin-top: calc(var(--header-h) + 12px); }
/* длинные слова в списке видео не распирают блок (320px) */
.cx, .cx-body, .cx-stage { min-width: 0; }
.cx { grid-template-columns: minmax(0, 1fr); }
.cx-rt { min-width: 0; }
.cx-rt b { overflow-wrap: anywhere; hyphens: auto; }
/* заглушка невышедшей темы — во всю ширину плеера */
.cx-player.is-black .black-cap { width: calc(100% - 48px); text-align: center; }
/* заголовки без «висячих» слов */
.h2, .cx-title, .trainer-intro .h2, .sim-body h3, .faq summary, .cx-pick-title { text-wrap: balance; }
/* уровни тренажёра в одну строку */
.levels span { white-space: nowrap; }
.levels i { width: auto; flex: 1 1 24px; max-width: 40px; }
/* бургер без меню не показываем */
.burger { display: none !important; }
/* пока открыт симулятор — переключатель гаммы не мешает */
body.sim-open .theme-switch { display: none; }
.sim-frame-head b { min-width: 0; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }

@media (max-width: 1023px) {
  .section { padding: 64px 0; }
  #sims { padding-bottom: 48px; }
  #faq { padding-top: 48px; }
}
@media (min-width: 768px) and (max-width: 1023px) {
  .steps-3 { grid-template-columns: repeat(3, 1fr); }
  .steps-3 .step { padding: 22px; }
  .steps-3 .step h3 { font-size: 21px; }
}
@media (max-width: 767px) {
  /* кнопка Play не лежит на подписи */
  .cx-player .big-play { top: 38%; width: 56px; height: 56px; }
  .cx-player .big-play svg { width: 20px; height: 20px; }
  .cx-player .player-cap .label { display: none; }
  /* тап-зоны не меньше 44px */
  .cx-toc .cx-chapters button { min-height: 44px; align-items: center; }
  .stepper button { width: 44px; height: 44px; }
  /* шрифты не мельче 12px */
  .cx-rt small, .tg-lock, .cx-tab-d, #game .label { font-size: 12px !important; }
  /* симулятор: по высоте экрана */
  .sim-frame iframe { height: calc(100svh - var(--header-h) - 70px); }
  .sim-frame-head { padding: 12px 14px; }
  .sim-frame-head b { font-size: 14px; }
  /* переключатель гаммы — компактный кружок */
  .theme-switch { width: 44px; height: 44px; padding: 0; justify-content: center; }
  .theme-switch .ts-label { display: none; }
  .section { padding: 48px 0; }
}
/* отступ под шапку задаёт только html scroll-padding — без дубля */
#cxPlayer, #cxHead, .sim-frame, #courseExplorer, #topics { scroll-margin-top: 0; }
/* превью видео без надписей и затемнения снизу */
.cx-player.player-card::after { display: none; }
.cx-player .big-play { top: 50% !important; }
.cx-list-title { margin-bottom: 18px; }