:root {
  --bg: #070b18;
  --surface: rgba(255, 255, 255, 0.08);
  --surface-strong: rgba(255, 255, 255, 0.14);
  --text: #f5f7fb;
  --muted: #aeb8cc;
  --line: rgba(255, 255, 255, 0.16);
  --brand: #7dd3fc;
  --brand-2: #a78bfa;
  --accent: #34d399;
  --radius: 28px;
  color-scheme: dark;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: Inter, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  background:
    radial-gradient(circle at 18% 8%, rgba(125, 211, 252, 0.22), transparent 28rem),
    radial-gradient(circle at 85% 18%, rgba(167, 139, 250, 0.2), transparent 26rem),
    linear-gradient(135deg, #070b18 0%, #10172a 46%, #07111f 100%);
  color: var(--text);
  line-height: 1.7;
}

a {
  color: inherit;
  text-decoration: none;
}

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

.container {
  width: min(1160px, calc(100% - 40px));
  margin: 0 auto;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  backdrop-filter: blur(18px);
  background: rgba(7, 11, 24, 0.74);
  border-bottom: 1px solid var(--line);
}

.nav-shell,
.footer-grid,
.hero-grid,
.two-column,
.layout-with-aside,
.faq-grid {
  display: grid;
  gap: 28px;
}

.nav-shell {
  grid-template-columns: 1fr auto;
  align-items: center;
  padding: 16px 0;
}

.brand,
.main-nav,
.hero-actions,
.anchor-grid,
.tag-row,
.tag-cloud,
.check-list {
  display: flex;
  align-items: center;
  gap: 12px;
  flex-wrap: wrap;
}

.brand {
  font-weight: 800;
  letter-spacing: -0.03em;
}

.brand img {
  width: 44px;
  height: 44px;
  border-radius: 14px;
}

.main-nav a,
.anchor-grid a,
.tag-cloud a,
.tag-row a,
.side-panel a,
.chapter-list a {
  border: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.06);
  border-radius: 999px;
  color: var(--muted);
  padding: 9px 14px;
  transition: 0.2s ease;
}

.main-nav a:hover,
.anchor-grid a:hover,
.tag-cloud a:hover,
.tag-row a:hover,
.side-panel a:hover,
.chapter-list a:hover {
  border-color: rgba(125, 211, 252, 0.8);
  color: var(--text);
  transform: translateY(-1px);
}

.hero-section,
.page-hero {
  padding: 88px 0 46px;
}

.hero-grid {
  grid-template-columns: minmax(0, 0.95fr) minmax(320px, 1.05fr);
  align-items: center;
}

.hero-copy h1,
.page-hero h1 {
  margin: 0;
  font-size: clamp(2.7rem, 7vw, 5.9rem);
  line-height: 0.96;
  letter-spacing: -0.08em;
}

.hero-copy p,
.page-hero p,
.section-heading p,
.feature-card p,
.article-card p,
.list-card p,
.download-card p {
  color: var(--muted);
}

.eyebrow {
  color: var(--brand);
  font-size: 0.76rem;
  font-weight: 800;
  letter-spacing: 0.18em;
  text-transform: uppercase;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: 999px;
  padding: 13px 20px;
  border: 1px solid var(--line);
  font-weight: 700;
}

.btn.primary,
.btn.small {
  background: linear-gradient(135deg, var(--brand), var(--brand-2));
  color: #06101d;
  border: 0;
}

.btn.ghost {
  background: rgba(255, 255, 255, 0.06);
}

.btn.small {
  padding: 10px 14px;
  font-size: 0.92rem;
}

.hero-panel {
  position: relative;
  padding: 12px;
  border: 1px solid var(--line);
  border-radius: 36px;
  background: linear-gradient(180deg, rgba(255, 255, 255, 0.14), rgba(255, 255, 255, 0.05));
  box-shadow: 0 24px 80px rgba(0, 0, 0, 0.32);
}

.hero-panel img {
  width: 100%;
  aspect-ratio: 1.18;
  border-radius: 28px;
}

.panel-card {
  position: absolute;
  right: 30px;
  bottom: 30px;
  border: 1px solid var(--line);
  background: rgba(7, 11, 24, 0.78);
  backdrop-filter: blur(16px);
  border-radius: 22px;
  padding: 16px 18px;
}

.panel-card span {
  display: block;
  color: var(--accent);
  font-size: 0.82rem;
}

.anchor-section {
  padding: 18px 0;
}

.anchor-grid {
  justify-content: center;
}

.section-block {
  padding: 72px 0;
}

.section-block.muted {
  background: rgba(255, 255, 255, 0.035);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.section-heading {
  display: flex;
  align-items: end;
  justify-content: space-between;
  gap: 18px;
  margin-bottom: 26px;
}

.section-heading h2,
.two-column h2,
.faq-grid h2 {
  margin: 0;
  font-size: clamp(1.8rem, 4vw, 3.1rem);
  letter-spacing: -0.05em;
}

.section-heading a {
  color: var(--brand);
  font-weight: 800;
}

.download-strip,
.article-grid,
.feature-grid,
.download-grid {
  display: grid;
  gap: 18px;
}

.download-strip {
  grid-template-columns: repeat(4, minmax(0, 1fr));
}

.article-grid,
.feature-grid {
  grid-template-columns: repeat(4, minmax(0, 1fr));
}

.download-grid.four {
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.mini-card,
.article-card,
.feature-card,
.list-card,
.download-card,
.side-panel,
.faq-list details {
  border: 1px solid var(--line);
  background: var(--surface);
  border-radius: var(--radius);
  padding: 14px;
  box-shadow: 0 18px 50px rgba(0, 0, 0, 0.18);
}

.mini-card img,
.article-card img,
.feature-card img,
.list-card img,
.download-card img {
  width: 100%;
  border-radius: 20px;
  aspect-ratio: 1.45;
}

.mini-card h3,
.article-card h3,
.feature-card h3,
.download-card h2,
.list-card h2 {
  margin: 14px 0 8px;
  line-height: 1.25;
  letter-spacing: -0.03em;
}

.mini-card a,
.article-card a,
.list-card h2 a {
  color: var(--brand);
  font-weight: 800;
}

.article-card time,
.list-card time {
  display: block;
  margin-top: 14px;
  color: var(--accent);
  font-size: 0.86rem;
}

.two-column {
  grid-template-columns: 0.9fr 1.1fr;
  align-items: center;
}

.chapter-list,
.side-panel,
.faq-list,
.check-list {
  display: grid;
  gap: 12px;
}

.page-hero.compact {
  padding-bottom: 30px;
}

.download-hero {
  background: linear-gradient(135deg, rgba(125, 211, 252, 0.08), rgba(167, 139, 250, 0.08));
}

.layout-with-aside {
  grid-template-columns: minmax(0, 1fr) 320px;
  align-items: start;
}

.article-list {
  display: grid;
  gap: 18px;
}

.list-card {
  display: grid;
  grid-template-columns: 260px 1fr;
  gap: 18px;
}

.side-panel {
  position: sticky;
  top: 92px;
}

.side-panel h2 {
  margin: 8px 0 0;
}

.tag-cloud.large a {
  padding: 14px 18px;
  font-size: 1.05rem;
}

.download-card {
  padding: 18px;
}

.check-list span {
  padding: 14px 16px;
  border-radius: 18px;
  background: var(--surface-strong);
}

.faq-grid {
  grid-template-columns: 0.8fr 1.2fr;
}

.faq-list summary {
  cursor: pointer;
  font-weight: 800;
}

.post-hero {
  padding: 62px 0 34px;
}

.post-header {
  max-width: 860px;
}

.post-header h1 {
  margin: 0;
  font-size: clamp(2.2rem, 6vw, 4.8rem);
  line-height: 1;
  letter-spacing: -0.07em;
}

.post-cover {
  margin-top: 28px;
  border-radius: 32px;
  width: 100%;
  max-height: 520px;
}

.post-layout {
  display: grid;
  grid-template-columns: minmax(0, 820px) 260px;
  gap: 36px;
  align-items: start;
}

.post-content {
  font-size: 1.08rem;
}

.post-content h2 {
  margin-top: 42px;
  font-size: 2rem;
  letter-spacing: -0.04em;
}

.post-content h3 {
  margin-top: 28px;
}

.post-content a {
  color: var(--brand);
  font-weight: 800;
}

.post-content img {
  border-radius: 24px;
  margin: 22px 0;
}

.video-frame {
  aspect-ratio: 16 / 9;
  width: 100%;
  border: 0;
  border-radius: 26px;
  background: #000;
}

.site-footer {
  padding: 42px 0;
  border-top: 1px solid var(--line);
  background: rgba(0, 0, 0, 0.18);
}

.footer-grid {
  grid-template-columns: 1fr auto;
  align-items: center;
}

.footer-grid nav {
  display: grid;
  gap: 8px;
}

@media (max-width: 980px) {
  .hero-grid,
  .two-column,
  .layout-with-aside,
  .faq-grid,
  .footer-grid,
  .post-layout {
    grid-template-columns: 1fr;
  }

  .download-strip,
  .article-grid,
  .feature-grid,
  .download-grid.four {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .side-panel {
    position: static;
  }
}

@media (max-width: 640px) {
  .container {
    width: min(100% - 28px, 1160px);
  }

  .nav-shell,
  .section-heading,
  .list-card {
    grid-template-columns: 1fr;
    display: grid;
  }

  .download-strip,
  .article-grid,
  .feature-grid,
  .download-grid.four {
    grid-template-columns: 1fr;
  }

  .hero-section,
  .page-hero {
    padding-top: 54px;
  }
}