@import url('https://fonts.googleapis.com/css2?family=IBM+Plex+Sans:wght@300;400;500;600;700&display=swap');

/* ============================================================
   CSS 变量与基础重置
   ============================================================ */
:root {
  --c-primary: #6514ff;
  --c-accent: #bf00ff;
  --c-ground: #1c1726;
  --c-ground2: #251e32;
  --c-ground3: #2f2840;
  --c-text: #f0eaff;
  --c-text-muted: #a999cc;
  --c-border: #6514ff;
  --c-border-accent: #bf00ff;
  --c-card-bg: #1c1726;
  --c-announce: #6514ff;
  --font: 'IBM Plex Sans', 'PingFang SC', 'Microsoft YaHei', system-ui, sans-serif;
  --radius: 0;
  --gap-lg: 48px;
  --gap-md: 32px;
  --gap-sm: 16px;
  --max-w: 1200px;
  --sidebar-w: 260px;
  --transition: 200ms ease;
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html {
  font-size: 17px;
  line-height: 1.6;
  background: var(--c-ground);
  color: var(--c-text);
  font-family: var(--font);
  scroll-behavior: smooth;
}

body { min-height: 100vh; overflow-x: hidden; }

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

a { color: var(--c-accent); text-decoration: none; transition: color var(--transition); }
a:hover { color: #fff; }
a:focus-visible { outline: 2px solid var(--c-accent); outline-offset: 2px; }

ul, ol { list-style: none; }

/* ============================================================
   公告条
   ============================================================ */
.announce-bar {
  background: var(--c-primary);
  color: #fff;
  text-align: center;
  font-size: 0.82rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  padding: 8px var(--gap-sm);
  position: relative;
  z-index: 10;
}

/* ============================================================
   侧边导航 aside > nav > ul > li > a
   ============================================================ */
.site-aside {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--c-ground2);
  border-bottom: 2px solid var(--c-primary);
  width: 100%;
}

.site-aside nav {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 var(--gap-sm);
}

.site-aside nav ul {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  padding: 10px 0;
  align-items: center;
}

.site-aside nav ul li { flex-shrink: 0; }

/* 药丸胶囊按钮 */
.pill-btn {
  display: inline-block;
  padding: 8px 16px;
  border-radius: 999px;
  border: 2px solid var(--c-primary);
  color: var(--c-text-muted);
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.02em;
  transition: background var(--transition), color var(--transition), border-color var(--transition);
  min-height: 40px;
  line-height: 1.2;
  white-space: nowrap;
}
.pill-btn:hover {
  background: var(--c-primary);
  color: #fff;
  border-color: var(--c-primary);
}
.pill-btn.active {
  background: var(--c-accent);
  border-color: var(--c-accent);
  color: #fff;
}

/* ============================================================
   主体布局：main > div > article  +  aside 侧边栏
   ============================================================ */
main {
  display: grid;
  grid-template-columns: 1fr var(--sidebar-w);
  gap: var(--gap-lg);
  max-width: var(--max-w);
  margin: 0 auto;
  padding: var(--gap-lg) var(--gap-sm);
  align-items: start;
}

main div {
  min-width: 0;
}

/* ============================================================
   Hero 区域（首页）
   ============================================================ */
.hero-section {
  position: relative;
  min-height: 45vh;
  display: flex;
  align-items: center;
  padding: var(--gap-lg) 0;
  overflow: hidden;
}

.hero-grid-bg {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(var(--c-primary) 1px, transparent 1px),
    linear-gradient(90deg, var(--c-primary) 1px, transparent 1px);
  background-size: 48px 48px;
  opacity: 0.1;
  animation: grid-drift 20s linear infinite;
  pointer-events: none;
}

@keyframes grid-drift {
  0% { background-position: 0 0; }
  100% { background-position: 48px 48px; }
}

@media (prefers-reduced-motion: reduce) {
  .hero-grid-bg { animation: none; }
  .stagger-item { animation: none !important; opacity: 1 !important; }
}

.hero-inner {
  position: relative;
  z-index: 1;
  max-width: 720px;
}

.hero-badge-row {
  display: flex;
  gap: 12px;
  margin-bottom: 20px;
}

.duotone-badge {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  font-size: 1.4rem;
  background: var(--c-primary);
  color: var(--c-accent);
  border: 2px solid var(--c-accent);
  filter: drop-shadow(0 0 8px var(--c-accent));
}
.duotone-badge.alt {
  background: var(--c-accent);
  color: var(--c-primary);
  border-color: var(--c-primary);
  filter: drop-shadow(0 0 8px var(--c-primary));
}

.hero-h1 {
  font-size: clamp(2rem, 5vw, 3.2rem);
  font-weight: 700;
  line-height: 1.15;
  letter-spacing: -0.01em;
  margin-bottom: 16px;
  background: linear-gradient(135deg, #fff 40%, var(--c-accent));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-lead {
  font-size: 1.1rem;
  color: var(--c-text-muted);
  margin-bottom: 28px;
  max-width: 560px;
  line-height: 1.7;
}

.hero-cta-row {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
}

/* CTA 按钮 */
.cta-btn {
  display: inline-block;
  padding: 12px 24px;
  font-size: 0.95rem;
  font-weight: 700;
  letter-spacing: 0.03em;
  border-radius: 0;
  transition: background var(--transition), color var(--transition), transform var(--transition);
  min-height: 44px;
  line-height: 1.2;
}
.cta-btn.primary {
  background: var(--c-primary);
  color: #fff;
  border: 2px solid var(--c-primary);
}
.cta-btn.primary:hover {
  background: var(--c-accent);
  border-color: var(--c-accent);
  color: #fff;
  transform: translateY(-2px);
}
.cta-btn.secondary {
  background: transparent;
  color: var(--c-accent);
  border: 2px solid var(--c-accent);
}
.cta-btn.secondary:hover {
  background: var(--c-accent);
  color: #fff;
  transform: translateY(-2px);
}
.cta-btn.small {
  font-size: 0.82rem;
  padding: 8px 16px;
  min-height: 36px;
}

/* ============================================================
   内页 Hero
   ============================================================ */
.inner-hero {
  position: relative;
  padding: var(--gap-md) 0;
  border-bottom: 3px solid var(--c-primary);
  overflow: hidden;
  margin-bottom: var(--gap-md);
}

.inner-hero-content {
  position: relative;
  z-index: 1;
}

.eyebrow-tag {
  display: inline-block;
  background: var(--c-accent);
  color: #fff;
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  padding: 4px 12px;
  margin-bottom: 12px;
  text-transform: uppercase;
}

.inner-hero h1 {
  font-size: clamp(1.6rem, 4vw, 2.4rem);
  font-weight: 700;
  line-height: 1.2;
  margin-bottom: 12px;
  color: #fff;
}

.meta-row {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
  margin-top: 12px;
}

.meta-date {
  font-size: 0.8rem;
  color: var(--c-text-muted);
  font-weight: 500;
}

/* ============================================================
   h2 + p.subtitle 组合
   ============================================================ */
h2 {
  font-size: clamp(1.3rem, 3vw, 1.8rem);
  font-weight: 700;
  color: #fff;
  line-height: 1.25;
  margin-bottom: 8px;
}

.subtitle {
  color: var(--c-text-muted);
  font-size: 0.95rem;
  margin-bottom: var(--gap-md);
  line-height: 1.6;
}

/* ============================================================
   内容区 article
   ============================================================ */
.content-section {
  margin-bottom: var(--gap-lg);
}

.page-content-wrap {
  border-left: 4px solid var(--c-primary);
  padding-left: var(--gap-md);
}

.section-prose {
  font-size: 1rem;
  line-height: 1.8;
  color: var(--c-text);
  max-width: 720px;
}

.section-prose h2,
.section-prose h3 {
  margin-top: 2em;
  margin-bottom: 0.5em;
}

.section-prose h2 { font-size: 1.4rem; }
.section-prose h3 { font-size: 1.15rem; color: var(--c-accent); }

.section-prose p { margin-bottom: 1em; }

.section-prose ul,
.section-prose ol {
  padding-left: 1.4em;
  margin-bottom: 1em;
  list-style: disc;
}
.section-prose ol { list-style: decimal; }

.section-prose li { margin-bottom: 0.4em; }

.section-prose a {
  color: var(--c-accent);
  text-decoration: underline;
  text-underline-offset: 3px;
}

.section-prose blockquote {
  border-left: 3px solid var(--c-accent);
  padding: 8px 16px;
  margin: 1.2em 0;
  background: var(--c-ground2);
  color: var(--c-text-muted);
  font-style: italic;
}

.section-prose table {
  width: 100%;
  border-collapse: collapse;
  margin-bottom: 1.2em;
  font-size: 0.9rem;
}
.section-prose th,
.section-prose td {
  border: 1px solid var(--c-ground3);
  padding: 8px 12px;
  text-align: left;
}
.section-prose th {
  background: var(--c-ground2);
  color: var(--c-accent);
  font-weight: 600;
}

.legal-prose {
  max-width: 680px;
}

/* ============================================================
   卡片网格
   ============================================================ */
.cards-section {
  margin-bottom: var(--gap-lg);
  padding: var(--gap-md) 0;
}

.cards-section.alt-bg {
  background: var(--c-ground2);
  padding: var(--gap-md);
  border: 2px solid var(--c-ground3);
}

.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
  gap: var(--gap-md);
}

.card {
  background: var(--c-ground2);
  border: 2px solid var(--c-primary);
  padding: var(--gap-md);
  position: relative;
  transition: border-color var(--transition), transform var(--transition);
  opacity: 0;
  animation: fadeSlideUp 400ms ease forwards;
  animation-delay: calc(var(--i, 0) * 80ms);
}

.card:hover {
  border-color: var(--c-accent);
  transform: translateY(-4px);
}

@keyframes fadeSlideUp {
  from { opacity: 0; transform: translateY(20px); }
  to { opacity: 1; transform: translateY(0); }
}

.card-badge {
  display: inline-block;
  font-size: 0.68rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  padding: 3px 10px;
  background: var(--c-primary);
  color: #fff;
  margin-bottom: 10px;
}

.card h3 {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 8px;
  line-height: 1.3;
}

.card h3 a {
  color: #fff;
}
.card h3 a:hover { color: var(--c-accent); }

.card .subtitle {
  font-size: 0.85rem;
  margin-bottom: 8px;
  color: var(--c-text-muted);
}

.card-date {
  font-size: 0.75rem;
  color: var(--c-text-muted);
  display: block;
}

/* ============================================================
   dl 相关列表  dl > dt > a + dd
   ============================================================ */
.related-list {
  display: grid;
  gap: 0;
}

.related-list dt {
  border-top: 1px solid var(--c-ground3);
  padding: 12px 0 4px;
  font-weight: 600;
  font-size: 1rem;
}

.related-list dt:first-child { border-top: none; }

.related-list dt a {
  color: #fff;
  transition: color var(--transition);
}
.related-list dt a:hover { color: var(--c-accent); }

.related-list dd {
  padding: 0 0 12px;
  color: var(--c-text-muted);
  font-size: 0.88rem;
  line-height: 1.5;
}

/* 子页 dl */
.child-dl {
  display: grid;
  gap: 0;
}
.child-dl dt {
  border-left: 3px solid var(--c-primary);
  padding: 10px 0 4px 12px;
  font-weight: 600;
  margin-top: 12px;
}
.child-dl dt a { color: #fff; }
.child-dl dt a:hover { color: var(--c-accent); }
.child-dl dd {
  padding: 0 0 8px 15px;
  color: var(--c-text-muted);
  font-size: 0.88rem;
}

/* ============================================================
   侧边栏 aside（内容右侧）
   ============================================================ */
.sidebar {
  position: sticky;
  top: 60px;
}

.sidebar-block {
  background: var(--c-ground2);
  border: 2px solid var(--c-ground3);
  padding: var(--gap-sm);
  margin-bottom: var(--gap-sm);
}

.sidebar-title {
  font-size: 0.88rem;
  font-weight: 700;
  letter-spacing: 0.05em;
  color: var(--c-accent);
  margin-bottom: 4px;
  text-transform: uppercase;
}

.sidebar-block h3.sidebar-title { font-size: 0.82rem; }

.sidebar-block p {
  font-size: 0.82rem;
  color: var(--c-text-muted);
  margin-bottom: 10px;
  line-height: 1.55;
}

.sidebar-links {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.sidebar-links li a {
  display: block;
  padding: 6px 8px;
  font-size: 0.83rem;
  color: var(--c-text-muted);
  border-left: 2px solid transparent;
  transition: color var(--transition), border-color var(--transition);
  min-height: 32px;
  line-height: 1.4;
}

.sidebar-links li a:hover,
.sidebar-links li a.active {
  color: #fff;
  border-left-color: var(--c-accent);
}

/* ============================================================
   关于页特有
   ============================================================ */
.about-stat-row {
  display: flex;
  gap: var(--gap-md);
  flex-wrap: wrap;
  margin-top: var(--gap-md);
  position: relative;
  z-index: 1;
}

.stat-block {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  padding: 16px 20px;
  border: 2px solid var(--c-primary);
  background: var(--c-ground2);
  min-width: 100px;
}

.stat-num {
  font-size: 2rem;
  font-weight: 700;
  color: var(--c-accent);
  line-height: 1;
}

.stat-label {
  font-size: 0.78rem;
  color: var(--c-text-muted);
  margin-top: 4px;
  font-weight: 500;
}

.about-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
  gap: var(--gap-md);
}

.about-grid-item {
  padding: var(--gap-sm);
  border: 2px solid var(--c-ground3);
  transition: border-color var(--transition);
}

.about-grid-item:hover { border-color: var(--c-primary); }

.about-grid-item h3 {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 6px;
  color: #fff;
}

.about-grid-item p {
  font-size: 0.85rem;
  color: var(--c-text-muted);
  line-height: 1.55;
}

.about-grid-section {
  margin-bottom: var(--gap-lg);
}

/* ============================================================
   Feature 页特有装饰
   ============================================================ */
.feature-hero {
  min-height: auto;
}

.feature-geo-deco {
  position: absolute;
  right: 0;
  top: 0;
  bottom: 0;
  width: 200px;
  pointer-events: none;
  overflow: hidden;
  z-index: 0;
}

.geo-shape {
  position: absolute;
  border: 2px solid;
  animation: geo-spin 12s linear infinite;
}
.geo-shape.s1 {
  width: 80px; height: 80px;
  border-color: var(--c-primary);
  top: 20%; right: 20px;
  animation-duration: 10s;
}
.geo-shape.s2 {
  width: 50px; height: 50px;
  border-color: var(--c-accent);
  top: 50%; right: 80px;
  animation-duration: 7s;
  animation-direction: reverse;
}
.geo-shape.s3 {
  width: 120px; height: 120px;
  border-color: var(--c-ground3);
  bottom: 10%; right: -20px;
  animation-duration: 15s;
}

@keyframes geo-spin {
  from { transform: rotate(0deg); }
  to { transform: rotate(360deg); }
}

@media (prefers-reduced-motion: reduce) {
  .geo-shape { animation: none; }
  .hero-grid-bg { animation: none; }
}

.feature-links-section {
  margin-bottom: var(--gap-lg);
}

/* ============================================================
   FAQ 特有
   ============================================================ */
.faq-content .section-prose h2 {
  font-size: 1.2rem;
  color: var(--c-accent);
  border-left: 3px solid var(--c-accent);
  padding-left: 10px;
  margin-top: 1.8em;
}

.faq-guide-section {
  margin-bottom: var(--gap-lg);
}

/* ============================================================
   页脚：footer 三列 dl
   ============================================================ */
footer {
  background: var(--c-ground2);
  border-top: 3px solid var(--c-primary);
  padding: var(--gap-lg) var(--gap-sm) 0;
  margin-top: var(--gap-lg);
}

.footer-inner {
  max-width: var(--max-w);
  margin: 0 auto;
  display: grid;
  grid-template-columns: 1fr 2fr;
  gap: var(--gap-lg);
  padding-bottom: var(--gap-lg);
}

.footer-brand {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.footer-brand strong {
  font-size: 1.1rem;
  font-weight: 700;
  color: #fff;
}

.footer-brand p {
  font-size: 0.83rem;
  color: var(--c-text-muted);
  line-height: 1.55;
}

.footer-cols {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--gap-md);
}

.footer-cols dl dt {
  font-size: 0.8rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  color: var(--c-accent);
  text-transform: uppercase;
  margin-bottom: 10px;
  padding-bottom: 6px;
  border-bottom: 1px solid var(--c-ground3);
}

.footer-cols dl dd {
  margin-bottom: 6px;
}

.footer-cols dl dd a {
  font-size: 0.85rem;
  color: var(--c-text-muted);
  transition: color var(--transition);
  display: block;
  min-height: 28px;
  line-height: 1.6;
}

.footer-cols dl dd a:hover { color: #fff; }

.footer-bottom {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 14px 0;
  border-top: 1px solid var(--c-ground3);
  font-size: 0.78rem;
  color: var(--c-text-muted);
  display: flex;
  align-items: center;
}

/* ============================================================
   导航内链节（privacy/faq 底部）
   ============================================================ */
.privacy-nav-section,
.nav-section {
  margin-bottom: var(--gap-lg);
}

/* ============================================================
   Privacy 特有
   ============================================================ */
.privacy-hero {}
.privacy-content .section-prose h2 {
  font-size: 1.2rem;
  margin-top: 2em;
  color: #fff;
}

/* ============================================================
   响应式断点
   ============================================================ */
@media (max-width: 900px) {
  main {
    grid-template-columns: 1fr;
    gap: var(--gap-md);
    padding: var(--gap-md) var(--gap-sm);
  }

  .sidebar {
    position: static;
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    gap: var(--gap-sm);
  }

  .sidebar-block {
    margin-bottom: 0;
  }

  .footer-inner {
    grid-template-columns: 1fr;
    gap: var(--gap-md);
  }

  .footer-cols {
    grid-template-columns: repeat(3, 1fr);
  }

  .feature-geo-deco { display: none; }
}

@media (max-width: 600px) {
  :root { --gap-lg: 32px; --gap-md: 20px; }

  .site-aside nav ul {
    gap: 6px;
  }

  .pill-btn {
    font-size: 0.72rem;
    padding: 7px 12px;
  }

  .hero-section { min-height: 40vh; }

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

  .footer-cols {
    grid-template-columns: 1fr;
    gap: var(--gap-md);
  }

  .about-stat-row {
    gap: 12px;
  }

  .hero-cta-row {
    flex-direction: column;
  }

  .cta-btn {
    width: 100%;
    text-align: center;
  }

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

  .meta-row {
    flex-direction: column;
    gap: 6px;
  }
}

/* ============================================================
   辅助工具
   ============================================================ */
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0,0,0,0);
  white-space: nowrap;
  border: 0;
}

/* 滚动快照（首页区块） */
@media (min-width: 900px) {
  .hero-section,
  .cards-section {
    scroll-snap-align: start;
  }
}