:root {
  --bg: #0e0e11;
  --bg-surface: #16161b;
  --bg-raised: #1e1e25;
  --bg-hover: #252530;
  --border: #2a2a36;
  --border-light: #35354a;
  --text: #d4d4dc;
  --text-muted: #8888a0;
  --text-heading: #eeeef4;
  --accent: #7b8cff;
  --accent-dim: #5a6ad4;
  --accent-bg: rgba(123, 140, 255, 0.08);
  --accent-border: rgba(123, 140, 255, 0.25);
  --warn: #e8a84c;
  --warn-bg: rgba(232, 168, 76, 0.08);
  --info: #5cb8d6;
  --info-bg: rgba(92, 184, 214, 0.08);
  --code-bg: #12121a;
  --nav-h: 60px;
  --content-w: 980px;
  --font: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: 84px;
}

body {
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  line-height: 1.7;
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
}

a {
  color: var(--accent);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

.site-nav {
  position: sticky;
  top: 0;
  z-index: 100;
  height: var(--nav-h);
  background: rgba(14, 14, 17, 0.92);
  border-bottom: 1px solid var(--border);
  backdrop-filter: blur(10px);
}

.site-nav-inner {
  max-width: var(--content-w);
  margin: 0 auto;
  height: 100%;
  padding: 0 20px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
}

.nav-right {
  display: flex;
  align-items: center;
  gap: 12px;
}

.brand {
  color: var(--text-heading);
  font-weight: 700;
  letter-spacing: -0.02em;
  font-size: 16px;
}

.brand span {
  color: var(--accent);
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 8px;
  flex-wrap: wrap;
}

.nav-links a {
  padding: 6px 10px;
  border-radius: 7px;
  color: var(--text-muted);
  font-size: 14px;
  transition: all 0.15s ease;
}

.nav-links a:hover {
  color: var(--text);
  text-decoration: none;
  background: var(--bg-hover);
}

.nav-links a.active {
  color: var(--accent);
  background: var(--accent-bg);
}

.nav-social {
  display: flex;
  align-items: center;
  gap: 8px;
}

.nav-social a {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 30px;
  height: 30px;
  border-radius: 7px;
  border: 1px solid var(--border);
  background: var(--bg-surface);
}

.nav-social a:hover {
  background: var(--bg-hover);
  text-decoration: none;
}

.container {
  max-width: var(--content-w);
  margin: 0 auto;
  padding: 38px 20px 90px;
}

.container section {
  margin-top: 14px;
}

h1 {
  margin: 0 0 10px;
  color: var(--text-heading);
  letter-spacing: -0.03em;
  font-size: clamp(28px, 5vw, 40px);
  line-height: 1.15;
}

h2 {
  margin: 40px 0 14px;
  color: var(--text-heading);
  font-size: 22px;
  letter-spacing: -0.02em;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--border);
}

p {
  margin: 0 0 14px;
}

.hero-subtitle {
  margin-bottom: 20px;
  color: var(--text-muted);
  font-size: 17px;
  max-width: 800px;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 22px;
}

.social-row {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin: 18px 0 18px;
}

.social-section h2 {
  margin-top: 20px;
}

.social-btn {
  display: inline-flex;
  align-items: center;
  gap: 10px;
}

.social-icon {
  width: 18px;
  height: 18px;
  object-fit: contain;
  display: inline-block;
}

.btn {
  display: inline-block;
  border-radius: 9px;
  border: 1px solid var(--border);
  background: var(--bg-surface);
  color: var(--text-heading);
  padding: 10px 16px;
  font-size: 14px;
  font-weight: 600;
  transition: all 0.15s ease;
}

.btn:hover {
  text-decoration: none;
  transform: translateY(-1px);
}

.btn-primary {
  background: var(--accent);
  border-color: var(--accent);
  color: var(--bg);
}

.btn-primary:hover {
  background: var(--accent-dim);
  border-color: var(--accent-dim);
}

.cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 14px;
  margin-top: 16px;
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
  margin-top: 16px;
}

.feature-list {
  margin: 0;
  padding-left: 18px;
}

.feature-list li {
  margin: 0 0 10px;
  color: var(--text);
}

.feature-list li:last-child {
  margin-bottom: 0;
}

.card {
  background: var(--bg-surface);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 16px;
}

.card h3 {
  margin: 0 0 8px;
  color: var(--text-heading);
  font-size: 17px;
}

.card p {
  margin-bottom: 0;
  color: var(--text-muted);
  font-size: 14px;
}

.note,
.warn {
  border-radius: 8px;
  border-left: 3px solid;
  padding: 13px 16px;
  margin: 14px 0;
  font-size: 14px;
}

.note {
  background: var(--info-bg);
  border-color: var(--info);
}

.warn {
  background: var(--warn-bg);
  border-color: var(--warn);
}

.video-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 16px;
}

.video-card {
  background: var(--bg-surface);
  border: 1px solid var(--border);
  border-radius: 10px;
  overflow: hidden;
}

.video-frame-wrap {
  position: relative;
  width: 100%;
  padding-top: 56.25%;
  background: var(--code-bg);
}

.video-frame-wrap iframe {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  border: 0;
}

.video-meta {
  padding: 14px 16px 16px;
}

.video-meta h3 {
  margin: 0 0 8px;
  color: var(--text-heading);
}

.video-meta p {
  margin: 0;
  color: var(--text-muted);
  font-size: 14px;
}

.footer {
  margin-top: 42px;
  padding-top: 18px;
  border-top: 1px solid var(--border);
  color: var(--text-muted);
  font-size: 13px;
}

@media (max-width: 700px) {
  .site-nav {
    height: auto;
    position: static;
  }

  .site-nav-inner {
    flex-direction: column;
    align-items: flex-start;
    padding-top: 12px;
    padding-bottom: 12px;
  }

  .nav-right {
    width: 100%;
    justify-content: space-between;
    flex-wrap: wrap;
  }

  .container {
    padding-top: 28px;
  }

  .features-grid {
    grid-template-columns: 1fr;
  }
}