@import url('https://fonts.googleapis.com/css2?family=Plus+Jakarta+Sans:ital,wght@0,400;0,600;0,700;0,800;1,400&display=swap');

/* ===== CSS 变量 ===== */
:root {
  --c-primary: #6366F1;
  --c-accent: #F43F5E;
  --c-dark: #1E1B4B;
  --c-primary-light: #818CF8;
  --c-primary-xlight: #E0E7FF;
  --c-accent-light: #FDA4AF;
  --c-bg: #F8F7FF;
  --c-bg2: #EEEDF8;
  --c-surface: #FFFFFF;
  --c-text: #1E1B4B;
  --c-text-muted: #6B7280;
  --c-border: #D1D5DB;
  --font: 'Plus Jakarta Sans', 'Segoe UI', system-ui, -apple-system, sans-serif;
  --radius: 4px;
  --anchor-h: 48px;
  --header-h: 64px;
  --transition: 160ms ease;
}

/* ===== 重置 ===== */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}
body {
  font-family: var(--font);
  font-size: 1rem;
  line-height: 1.7;
  color: var(--c-text);
  background: var(--c-bg);
  min-width: 320px;
  overflow-x: hidden;
}
img { display: block; max-width: 100%; height: auto; }
a { color: inherit; text-decoration: none; }
ul, ol { list-style: none; }
h1, h2, h3, h4, h5, h6 { line-height: 1.2; font-weight: 800; }

/* ===== 工具 ===== */
.visually-hidden {
  position: absolute; width: 1px; height: 1px;
  overflow: hidden; clip: rect(0,0,0,0); white-space: nowrap;
}

/* ===== scroll-margin-top（锚点区块，留出 header + anchor-bar 高度） ===== */
article[id] {
  scroll-margin-top: calc(var(--header-h) + var(--anchor-h) + 8px);
}

/* ===== 站头 ===== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--c-dark);
  height: var(--header-h);
  border-bottom: 2px solid var(--c-primary);
}
.header-inner {
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 24px;
  height: 100%;
  display: flex;
  align-items: center;
  gap: 24px;
}
.brand-link {
  display: flex;
  align-items: center;
  gap: 8px;
  flex-shrink: 0;
  text-decoration: none;
}
.logo-img { height: 36px; width: auto; }
.logo-text {
  font-size: 1.2rem;
  font-weight: 800;
  color: #fff;
  letter-spacing: -0.02em;
}

/* ===== 主导航（header nav > p > a） ===== */
.main-nav { flex: 1; overflow: hidden; }
.nav-row {
  display: flex;
  flex-wrap: nowrap;
  gap: 4px;
  align-items: center;
  overflow-x: auto;
  scrollbar-width: none;
}
.nav-row::-webkit-scrollbar { display: none; }
.nav-row a {
  color: rgba(255,255,255,0.8);
  font-size: 0.875rem;
  font-weight: 600;
  padding: 8px 12px;
  border-radius: var(--radius);
  white-space: nowrap;
  transition: background var(--transition), color var(--transition);
  min-height: 40px;
  display: inline-flex;
  align-items: center;
}
.nav-row a:hover, .nav-row a:focus-visible {
  background: var(--c-primary);
  color: #fff;
  outline: none;
}

/* ===== 汉堡按钮 ===== */
.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 10px;
  min-width: 40px;
  min-height: 40px;
  margin-left: auto;
}
.bar {
  display: block;
  width: 22px;
  height: 2px;
  background: #fff;
  border-radius: 2px;
  transition: transform var(--transition), opacity var(--transition);
}
.nav-toggle[aria-expanded="true"] .bar:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] .bar:nth-child(2) { opacity: 0; }
.nav-toggle[aria-expanded="true"] .bar:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* ===== 移动端菜单 ===== */
.mobile-menu {
  display: none;
  position: fixed;
  top: var(--header-h);
  left: 0; right: 0;
  background: var(--c-dark);
  z-index: 99;
  border-bottom: 2px solid var(--c-primary);
  padding: 12px 24px 20px;
  transform: translateY(-100%);
  transition: transform 200ms ease;
}
.mobile-menu.open {
  transform: translateY(0);
}
.mobile-nav-row {
  display: flex;
  flex-direction: column;
  gap: 4px;
}
.mobile-nav-row a {
  color: rgba(255,255,255,0.85);
  font-size: 1rem;
  font-weight: 600;
  padding: 12px 16px;
  border-radius: var(--radius);
  min-height: 44px;
  display: flex;
  align-items: center;
  transition: background var(--transition), color var(--transition);
}
.mobile-nav-row a:hover, .mobile-nav-row a:focus-visible {
  background: var(--c-primary);
  color: #fff;
}

/* ===== 锚点条 ===== */
.anchor-bar {
  position: sticky;
  top: var(--header-h);
  z-index: 90;
  background: var(--c-primary);
  height: var(--anchor-h);
  border-bottom: 2px solid var(--c-primary-light);
}
.anchor-inner {
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 24px;
  height: 100%;
  display: flex;
  align-items: center;
  gap: 4px;
  overflow-x: auto;
  scrollbar-width: none;
}
.anchor-inner::-webkit-scrollbar { display: none; }
.anchor-link {
  color: rgba(255,255,255,0.85);
  font-size: 0.8125rem;
  font-weight: 700;
  padding: 6px 12px;
  border-radius: var(--radius);
  white-space: nowrap;
  min-height: 36px;
  display: inline-flex;
  align-items: center;
  transition: background var(--transition), color var(--transition);
  letter-spacing: 0.01em;
}
.anchor-link:hover, .anchor-link:focus-visible {
  background: rgba(255,255,255,0.2);
  color: #fff;
  outline: none;
}

/* ===== Hero ===== */
.hero-section {
  background: var(--c-dark);
  position: relative;
  overflow: hidden;
}
.hero-article {
  position: relative;
  min-height: 45vh;
  display: flex;
  align-items: center;
  justify-content: center;
}
.hero-bg-grid {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(to right, rgba(99,102,241,0.18) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(99,102,241,0.18) 1px, transparent 1px);
  background-size: 40px 40px;
  pointer-events: none;
}
.hero-content {
  position: relative;
  z-index: 2;
  text-align: center;
  padding: 64px 24px;
  max-width: 900px;
  margin: 0 auto;
}
.hero-h1 {
  font-size: clamp(2rem, 6vw, 4rem);
  font-weight: 800;
  color: #fff;
  letter-spacing: -0.03em;
  margin-bottom: 20px;
}
.hero-sub {
  font-size: clamp(1rem, 2vw, 1.25rem);
  color: rgba(255,255,255,0.7);
  max-width: 600px;
  margin: 0 auto;
  font-weight: 400;
}

/* ===== main > section.wrap > article > div 结构 ===== */
main { display: block; }
.wrap {
  max-width: 1280px;
  margin: 0 auto;
  padding: 0;
}

/* ===== 内容区（含 aside 在左） ===== */
.content-section {
  padding: 48px 24px;
  background: var(--c-bg);
}
.content-article {
  display: flex;
  gap: 32px;
  align-items: flex-start;
}

/* aside 在内容左侧 */
.content-aside {
  width: 220px;
  flex-shrink: 0;
  position: sticky;
  top: calc(var(--header-h) + var(--anchor-h) + 16px);
}
.aside-inner {
  background: var(--c-surface);
  border: 2px solid var(--c-primary);
  border-radius: var(--radius);
  padding: 20px;
}
.aside-title {
  font-size: 0.875rem;
  font-weight: 800;
  color: var(--c-primary);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: 4px;
}
.aside-desc {
  font-size: 0.75rem;
  color: var(--c-text-muted);
  margin-bottom: 16px;
}
.aside-nav {
  display: flex;
  flex-direction: column;
  gap: 4px;
}
.aside-link {
  display: flex;
  align-items: center;
  font-size: 0.8125rem;
  font-weight: 600;
  color: var(--c-dark);
  padding: 8px 10px;
  border-radius: var(--radius);
  border-left: 3px solid transparent;
  transition: border-color var(--transition), background var(--transition), color var(--transition);
  min-height: 36px;
}
.aside-link:hover, .aside-link:focus-visible {
  border-left-color: var(--c-accent);
  background: var(--c-primary-xlight);
  color: var(--c-primary);
  outline: none;
}

/* 正文主体 */
.content-main { flex: 1; min-width: 0; }
.page-content { width: 100%; }

/* ===== page.content 内的元素样式 ===== */
.page-content h2 {
  font-size: clamp(1.3rem, 3vw, 1.75rem);
  font-weight: 800;
  color: var(--c-dark);
  margin-top: 56px;
  margin-bottom: 8px;
  padding-bottom: 8px;
  border-bottom: 3px solid var(--c-primary);
  letter-spacing: -0.02em;
}
.page-content h2:first-child { margin-top: 0; }
.page-content h3 {
  font-size: 1.125rem;
  font-weight: 700;
  color: var(--c-primary);
  margin-top: 28px;
  margin-bottom: 6px;
}
.page-content p {
  font-size: 1rem;
  line-height: 1.8;
  color: var(--c-text);
  margin-bottom: 16px;
}
.page-content ul, .page-content ol {
  margin-bottom: 16px;
  padding-left: 20px;
}
.page-content ul { list-style: disc; }
.page-content ol { list-style: decimal; }
.page-content li {
  font-size: 1rem;
  line-height: 1.75;
  color: var(--c-text);
  margin-bottom: 6px;
}
.page-content a {
  color: var(--c-primary);
  font-weight: 600;
  border-bottom: 1px solid var(--c-primary-light);
  transition: color var(--transition), border-color var(--transition);
}
.page-content a:hover {
  color: var(--c-accent);
  border-bottom-color: var(--c-accent);
}
.page-content strong { font-weight: 700; color: var(--c-dark); }
.page-content em { font-style: italic; color: var(--c-text-muted); }
.page-content blockquote {
  border-left: 4px solid var(--c-primary);
  background: var(--c-primary-xlight);
  padding: 16px 20px;
  border-radius: 0 var(--radius) var(--radius) 0;
  margin: 20px 0;
  font-style: italic;
  color: var(--c-dark);
}
.page-content table {
  width: 100%;
  border-collapse: collapse;
  margin-bottom: 20px;
  font-size: 0.9375rem;
}
.page-content th {
  background: var(--c-primary);
  color: #fff;
  font-weight: 700;
  padding: 10px 14px;
  text-align: left;
}
.page-content td {
  padding: 9px 14px;
  border-bottom: 1px solid var(--c-border);
}
.page-content tr:nth-child(even) td { background: var(--c-bg2); }
.page-content code {
  background: var(--c-bg2);
  color: var(--c-accent);
  padding: 2px 6px;
  border-radius: var(--radius);
  font-size: 0.875em;
  font-family: 'Courier New', monospace;
}
.page-content pre {
  background: var(--c-dark);
  color: #E0E7FF;
  padding: 20px;
  border-radius: var(--radius);
  overflow-x: auto;
  margin-bottom: 20px;
  font-size: 0.875rem;
  line-height: 1.6;
}
.page-content pre code { background: none; color: inherit; padding: 0; }
.page-content img {
  border-radius: var(--radius);
  max-width: 100%;
  margin: 16px 0;
}

/* ===== article 区块分隔（page.content 内的 article） ===== */
.page-content article {
  padding: 40px 0;
  border-bottom: 1px solid var(--c-border);
}
.page-content article:last-child { border-bottom: none; }

/* ===== 页脚 CTA 区块 ===== */
.footer-cta-block {
  background: var(--c-primary);
  text-align: center;
  padding: 64px 24px 48px;
}
.footer-cta-title {
  font-size: clamp(1.5rem, 4vw, 2.5rem);
  font-weight: 800;
  color: #fff;
  margin-bottom: 12px;
  letter-spacing: -0.02em;
}
.footer-cta-sub {
  color: rgba(255,255,255,0.75);
  font-size: 1.0625rem;
  margin-bottom: 28px;
}
.cta-btn {
  display: inline-flex;
  align-items: center;
  background: var(--c-accent);
  color: #fff;
  font-size: 1rem;
  font-weight: 800;
  padding: 14px 32px;
  border-radius: var(--radius);
  letter-spacing: 0.01em;
  min-height: 48px;
  transition: background var(--transition);
}
.cta-btn:hover, .cta-btn:focus-visible {
  background: #e11d48;
  outline: none;
}

/* ===== 页脚主体（footer 直接子层有 section + nav） ===== */
.site-footer { background: var(--c-dark); }
.footer-row {
  max-width: 1280px;
  margin: 0 auto;
  padding: 32px 24px;
  display: flex;
  align-items: center;
  gap: 32px;
  flex-wrap: wrap;
}
.footer-brand {
  display: flex;
  align-items: center;
  gap: 12px;
  flex-shrink: 0;
}
.footer-brand .logo-text { font-size: 1rem; font-weight: 800; color: #fff; }
.footer-brand .logo-img { height: 28px; }
.footer-copy {
  font-size: 0.8125rem;
  color: rgba(255,255,255,0.45);
  white-space: nowrap;
}
.footer-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 4px;
  flex: 1;
}
.footer-nav a {
  font-size: 0.8125rem;
  font-weight: 600;
  color: rgba(255,255,255,0.6);
  padding: 8px 10px;
  border-radius: var(--radius);
  min-height: 36px;
  display: inline-flex;
  align-items: center;
  transition: color var(--transition), background var(--transition);
}
.footer-nav a:hover, .footer-nav a:focus-visible {
  color: #fff;
  background: rgba(255,255,255,0.08);
}
.footer-info {
  flex-shrink: 0;
  max-width: 260px;
}
.footer-desc {
  font-size: 0.75rem;
  color: rgba(255,255,255,0.35);
  line-height: 1.6;
}

/* ===== 动效（prefers-reduced-motion 关闭） ===== */
@media (prefers-reduced-motion: no-preference) {
  .page-content article {
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 300ms ease, transform 300ms ease;
  }
  .page-content article.visible {
    opacity: 1;
    transform: translateY(0);
  }
  .aside-link {
    transition: border-color 160ms ease, background 160ms ease, color 160ms ease;
  }
  .anchor-link {
    transition: background 160ms ease, color 160ms ease;
  }
}

/* ===== 玻璃拟态卡片 ===== */
.glass-card {
  background: rgba(255,255,255,0.85);
  border: 1px solid rgba(99,102,241,0.2);
  border-radius: var(--radius);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  padding: 20px;
  transition: border-color var(--transition);
}
.glass-card:hover { border-color: var(--c-primary); }

/* ===== h2 + p.subtitle 标题装饰模式 ===== */
.section-header { margin-bottom: 32px; }
.section-header h2 {
  font-size: clamp(1.25rem, 3vw, 1.875rem);
  font-weight: 800;
  color: var(--c-dark);
  margin-bottom: 8px;
  letter-spacing: -0.02em;
}
.section-header p.subtitle {
  font-size: 1rem;
  color: var(--c-text-muted);
  font-weight: 400;
}

/* ===== 响应式 ===== */
@media (max-width: 1024px) {
  .content-aside { width: 180px; }
}

@media (max-width: 768px) {
  :root {
    --header-h: 56px;
    --anchor-h: 44px;
  }
  .main-nav { display: none; }
  .nav-toggle { display: flex; }
  .mobile-menu { display: block; }

  .content-article {
    flex-direction: column;
    gap: 24px;
  }
  .content-aside {
    width: 100%;
    position: static;
  }
  .aside-nav {
    flex-direction: row;
    flex-wrap: wrap;
  }
  .aside-link { min-height: 40px; }

  .footer-row {
    flex-direction: column;
    align-items: flex-start;
    gap: 20px;
  }
  .footer-info { max-width: 100%; }
  .footer-brand { flex-wrap: wrap; }
}

@media (max-width: 480px) {
  .content-section { padding: 32px 16px; }
  .hero-content { padding: 48px 16px; }
  .anchor-inner { padding: 0 12px; }
  .header-inner { padding: 0 16px; }
  .footer-cta-block { padding: 48px 16px 40px; }
  .footer-row { padding: 24px 16px; }
}

button[aria-expanded]{min-width:44px;min-height:44px}