/* Базовые переменные темы (космос) */
:root {
  --bg: #0b0f1a;
  --bg-alt: #0f1524;
  --text: #e6ecff;
  --muted: #a8b0c9;
  --primary: #7aa2ff;
  --accent: #9bffd6;
  --card: #121a2d;
  --border: #1d2741;

  --radius: 12px;
  --shadow: 0 6px 24px rgba(0,0,0,0.4);
}

* { box-sizing: border-box; }
html, body { height: 100%; }
body {
  margin: 0;
  color: var(--text);
  background: radial-gradient(1200px 800px at 80% -10%, #162041 0%, rgba(11,15,26,0) 60%), var(--bg);
  font-family: system-ui, -apple-system, Segoe UI, Roboto, Ubuntu, "Helvetica Neue", Arial, "Noto Sans", "Apple Color Emoji", "Segoe UI Emoji", "Segoe UI Symbol";
  line-height: 1.6;
}

img { max-width: 100%; display: block; }

/* Контейнеры */
.container { width: min(1120px, 92%); margin-inline: auto; }

/* Хедер и навигация */
.site-header {
  position: sticky; top: 0; z-index: 1000;
  background: rgba(11,15,26,0.75);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border);
}
.header-inner { display: flex; align-items: center; justify-content: space-between; padding: 14px 0; }
.logo { display: inline-flex; align-items: center; gap: 10px; color: var(--text); text-decoration: none; font-weight: 700; letter-spacing: 0.4px; }
.logo-mark { color: var(--accent); font-size: 20px; }
.logo-text { font-size: 18px; }

.nav-toggle { display: none; background: none; border: 0; cursor: pointer; }
.nav-toggle .bar { display: block; width: 22px; height: 2px; background: var(--text); margin: 4px 0; border-radius: 1px; }

.nav-list { display: flex; gap: 14px; list-style: none; margin: 0; padding: 0; }
.nav-link { color: var(--text); text-decoration: none; padding: 8px 12px; border-radius: 8px; }
.nav-link:hover { background: var(--bg-alt); }
.nav-link.active { background: var(--primary); color: #0c1120; }

/* Hero */
.hero { padding: 48px 0 24px; }
.hero-inner { display: grid; gap: 28px; grid-template-columns: 1.1fr 0.9fr; align-items: center; }
.hero-copy h1 { margin: 0 0 8px; font-size: clamp(28px, 4vw, 44px); line-height: 1.15; }
.hero-copy p { margin: 0 0 18px; color: var(--muted); }
.hero-actions { display: flex; gap: 12px; }

.btn { display: inline-block; padding: 10px 16px; border-radius: 10px; text-decoration: none; font-weight: 600; transition: transform .15s ease, background .2s ease; }
.btn:hover { transform: translateY(-1px); }
.btn-primary { background: var(--primary); color: #041126; }
.btn-secondary { background: #1a2748; color: var(--text); border: 1px solid var(--border); }
.btn-accent { background: var(--accent); color: #04201a; }

.hero-media { border-radius: var(--radius); overflow: hidden; box-shadow: var(--shadow); border: 1px solid var(--border); }

/* Features */
.features { padding: 28px 0 12px; }
.section-title { font-size: 22px; margin: 0 0 16px; }
.grid { display: grid; gap: 16px; }
.features-grid { grid-template-columns: repeat(3, 1fr); }
.card {
  background: linear-gradient(180deg, var(--card), #0f172a);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 16px;
  box-shadow: var(--shadow);
}
.card-icon { font-size: 22px; }
.card h3 { margin: 6px 0 8px; font-size: 18px; }
.card p { margin: 0 0 10px; color: var(--muted); }
.link { color: var(--accent); text-decoration: none; }
.link:hover { text-decoration: underline; }

/* Доп. космо-стиль и плашки */
.starfield {
  position: fixed; inset: 0; z-index: -1; pointer-events: none;
  background-image:
    radial-gradient(1px 1px at 10% 20%, rgba(255,255,255,0.35) 1px, transparent 1px),
    radial-gradient(1px 1px at 70% 40%, rgba(255,255,255,0.28) 1px, transparent 1px),
    radial-gradient(1px 1px at 30% 80%, rgba(255,255,255,0.25) 1px, transparent 1px);
  background-size: 120px 120px, 180px 180px, 240px 240px;
  background-repeat: repeat;
  opacity: 0.7;
}

.card:hover { transform: translateY(-2px); box-shadow: 0 10px 28px rgba(0,0,0,0.5); transition: transform .18s ease, box-shadow .2s ease; }
.card.glow { border-color: rgba(122,162,255,0.5); box-shadow: 0 0 0 1px rgba(122,162,255,0.2), 0 12px 36px rgba(38,72,170,0.25); }
.card.accent { border-color: rgba(155,255,214,0.45); background: linear-gradient(180deg, rgba(18,26,45,0.95), rgba(8,18,34,0.95)); box-shadow: 0 0 0 1px rgba(155,255,214,0.18); }
.card.outline { background: transparent; }

.badge { display: inline-block; padding: 2px 8px; border-radius: 999px; font-size: 12px; line-height: 1.6; border: 1px solid var(--border); color: var(--text); background: rgba(18,26,45,0.6); }
.badge.primary { border-color: rgba(122,162,255,0.5); background: rgba(122,162,255,0.12); }
.badge.accent { border-color: rgba(155,255,214,0.5); background: rgba(155,255,214,0.12); }

.topics-grid { grid-template-columns: repeat(3, 1fr); }
.media-card { display: grid; grid-template-columns: 72px 1fr; gap: 12px; align-items: center; }
.media-card .thumb { width: 72px; height: 72px; border-radius: 10px; overflow: hidden; border: 1px solid var(--border); }
.media-card img { width: 100%; height: 100%; object-fit: cover; display: block; }

/* CTA */
.cta { padding: 20px 0 40px; }
.cta-inner {
  background: linear-gradient(135deg, rgba(122,162,255,0.18), rgba(155,255,214,0.12));
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px;
  text-align: center;
}

/* Страницы */
.page { padding: 24px 0 36px; }
.page h1 { margin: 0 0 12px; font-size: clamp(24px, 3.4vw, 34px); }
.page h2 { margin: 18px 0 8px; font-size: 20px; }
.page p, .page li { color: var(--text); }

/* Оглавление подразделов */
.subnav { margin: 12px 0 18px; }
.subnav ul { display: flex; flex-wrap: wrap; gap: 8px; list-style: none; margin: 0; padding: 0; }
.subnav a { display: inline-block; padding: 6px 10px; border: 1px solid var(--border); border-radius: 8px; color: var(--text); text-decoration: none; background: rgba(16,22,39,0.5); }
.subnav a:hover { background: var(--bg-alt); }

/* Списки на страницах */
.page ul, .page ol { padding-left: 20px; margin: 8px 0 12px; }
.page li + li { margin-top: 6px; }

/* Футер */
.site-footer { border-top: 1px solid var(--border); background: rgba(11,15,26,0.7); }
.footer-inner { padding: 18px 0; }
.footer-cols { display: grid; gap: 14px; grid-template-columns: repeat(2, 1fr); margin-top: 10px; }
.footer-col h4 { margin: 0 0 8px; font-size: 14px; color: var(--muted); }
.footer-col ul { margin: 0; padding: 0; list-style: none; }
.footer-col a { color: var(--text); text-decoration: none; }
.footer-col a:hover { text-decoration: underline; }
.footer-copy { margin-top: 10px; color: var(--muted); font-size: 14px; }

/* Адаптив */
@media (max-width: 900px) {
  .hero-inner { grid-template-columns: 1fr; }
  .features-grid { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 640px) {
  .nav-toggle { display: inline-block; }
  .nav-list { position: absolute; right: 4%; top: 58px; background: var(--bg-alt); border: 1px solid var(--border); border-radius: 10px;
              padding: 8px; display: none; flex-direction: column; width: min(220px, 92vw); }
  .nav-list.open { display: flex; }
  .nav-link { padding: 10px 12px; }
  .features-grid { grid-template-columns: 1fr; }
}