/* === 基础重置 === */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700;800&family=Noto+Sans+SC:wght@400;500;600;700&display=swap');

:root {
  --color-bg: #ffffff;
  --color-bg-subtle: #f8fafc;
  --color-bg-muted: #f1f5f9;
  --color-text: #0f172a;
  --color-text-secondary: #475569;
  --color-text-muted: #64748b;
  --color-primary: #dc2626;
  --color-primary-soft: #fef2f2;
  --color-primary-border: #fecaca;
  --color-accent: #2563eb;
  --color-accent-soft: #eff6ff;
  --color-border: #e2e8f0;
  --color-border-light: #f1f5f9;
  --color-success: #16a34a;
  --color-success-soft: #f0fdf4;
  --color-warning: #d97706;
  --color-warning-soft: #fffbeb;
  --color-danger: #dc2626;
  --color-danger-soft: #fef2f2;
  --nav-height: 60px;
  --content-max: 820px;
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 14px;
  --radius-xl: 20px;
  --shadow-sm: 0 1px 2px rgba(0,0,0,0.04);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.06);
  --shadow-lg: 0 8px 24px rgba(0,0,0,0.08);
  --shadow-xl: 0 12px 36px rgba(0,0,0,0.1);
  --font-sans: 'Inter', 'Noto Sans SC', -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", sans-serif;
  --font-mono: 'JetBrains Mono', 'SF Mono', 'Fira Code', monospace;
  --transition: 200ms cubic-bezier(0.4, 0, 0.2, 1);
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--nav-height) + 1.5rem);
}

body {
  font-family: var(--font-sans);
  color: var(--color-text);
  background: var(--color-bg-subtle);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

@media (prefers-reduced-motion: reduce) {
  * { transition-duration: 0.01ms !important; animation-duration: 0.01ms !important; }
}

/* === 导航栏 === */
.top-nav {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255,255,255,0.85);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--color-border);
}

.nav-inner {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 2rem;
  display: flex;
  align-items: center;
  height: var(--nav-height);
  gap: 0.5rem;
}

.nav-brand {
  font-weight: 800;
  font-size: 0.9375rem;
  color: var(--color-primary);
  text-decoration: none;
  margin-right: auto;
  white-space: nowrap;
  letter-spacing: -0.01em;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.nav-brand::before {
  content: '';
  display: inline-block;
  width: 24px;
  height: 24px;
  background: var(--color-primary);
  border-radius: 6px;
  /* VEX 字标 */
  mask-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='white'%3E%3Cpath d='M4 5h2l4 7-4 7H4l4-7L4 5zm6 0h2l4 7-4 7h-2l4-7-4-7zm6 0h2l4 7-4 7h-2l4-7-4-7z'/%3E%3C/svg%3E");
  -webkit-mask-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='white'%3E%3Cpath d='M4 5h2l4 7-4 7H4l4-7L4 5zm6 0h2l4 7-4 7h-2l4-7-4-7zm6 0h2l4-7-4 7h-2l4-7-4-7z'/%3E%3C/svg%3E");
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 0.125rem;
}

.nav-links a, .nav-dropdown-label {
  padding: 0.5rem 0.875rem;
  border-radius: var(--radius-sm);
  font-size: 0.8125rem;
  font-weight: 500;
  color: var(--color-text-secondary);
  text-decoration: none;
  cursor: pointer;
  transition: background var(--transition), color var(--transition);
}

.nav-links a:hover, .nav-dropdown-label:hover {
  background: var(--color-bg-muted);
  color: var(--color-text);
}

.nav-links a.active {
  color: var(--color-primary);
  font-weight: 600;
  background: var(--color-primary-soft);
}

.nav-dropdown { position: relative; }

.nav-dropdown.active > .nav-dropdown-label {
  color: var(--color-primary);
  font-weight: 600;
}

.nav-dropdown-menu {
  display: none;
  position: absolute;
  top: calc(100% + 4px);
  left: 50%;
  transform: translateX(-50%);
  min-width: 200px;
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 0.375rem;
  box-shadow: var(--shadow-lg);
}

.nav-dropdown-menu a {
  display: block;
  white-space: nowrap;
  border-radius: var(--radius-sm);
}

.nav-dropdown:hover .nav-dropdown-menu { display: block; }

.nav-toggle {
  display: none;
  background: none;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  font-size: 1.25rem;
  cursor: pointer;
  padding: 0.375rem 0.5rem;
  color: var(--color-text-secondary);
  transition: background var(--transition);
}

.nav-toggle:hover { background: var(--color-bg-muted); }

/* === 布局 === */
.layout {
  max-width: 1200px;
  margin: 0 auto;
  padding: 2.5rem 2rem;
  display: flex;
  gap: 3rem;
}

.content {
  flex: 1;
  min-width: 0;
  max-width: var(--content-max);
  background: var(--color-bg);
  border-radius: var(--radius-lg);
  padding: 2.5rem;
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--color-border-light);
}

.content.has-toc { max-width: none; }

/* === 目录侧边栏 === */
.toc {
  position: sticky;
  top: calc(var(--nav-height) + 2.5rem);
  width: 220px;
  flex-shrink: 0;
  align-self: flex-start;
  max-height: calc(100vh - var(--nav-height) - 5rem);
  overflow-y: auto;
  font-size: 0.8125rem;
  order: 1;
  padding-right: 0.5rem;
}

.toc::-webkit-scrollbar { width: 3px; }
.toc::-webkit-scrollbar-thumb { background: var(--color-border); border-radius: 3px; }

.toc-title {
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: 0.875rem;
  font-size: 0.6875rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
}

.toc ul {
  list-style: none;
  border-left: 2px solid var(--color-border);
  padding-left: 0;
}

.toc li {
  padding: 0.25rem 0 0.25rem 1rem;
  border-left: 2px solid transparent;
  margin-left: -2px;
  transition: border-color var(--transition);
}

.toc li.toc-sub { padding-left: 2rem; }

.toc a {
  color: var(--color-text-muted);
  text-decoration: none;
  transition: color var(--transition);
  line-height: 1.4;
}

.toc li:hover { border-left-color: var(--color-primary); }
.toc li:hover a { color: var(--color-primary); }

/* === 正文排版 === */
.content h1 {
  font-size: 1.875rem;
  font-weight: 800;
  margin-bottom: 1.25rem;
  line-height: 1.25;
  color: var(--color-text);
  letter-spacing: -0.02em;
}

.content h2 {
  font-size: 1.375rem;
  font-weight: 700;
  margin: 3rem 0 1rem;
  padding-bottom: 0.5rem;
  border-bottom: 2px solid var(--color-border);
  letter-spacing: -0.01em;
  color: var(--color-text);
}

.content h3 {
  font-size: 1.0625rem;
  font-weight: 600;
  margin: 2rem 0 0.625rem;
  color: var(--color-text);
}

.content h4 {
  font-size: 0.9375rem;
  font-weight: 600;
  margin: 1.5rem 0 0.5rem;
  color: var(--color-text-secondary);
}

.content p { margin-bottom: 0.875rem; color: var(--color-text-secondary); }
.content ul, .content ol { margin: 0.5rem 0 1.25rem 1.5rem; color: var(--color-text-secondary); }
.content li { margin-bottom: 0.375rem; }
.content li > ul, .content li > ol { margin-top: 0.25rem; margin-bottom: 0.25rem; }
.content strong { font-weight: 600; color: var(--color-text); }

.content blockquote {
  border-left: 3px solid var(--color-primary);
  background: var(--color-primary-soft);
  padding: 1rem 1.25rem;
  margin: 1.25rem 0;
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  color: var(--color-text-secondary);
  font-size: 0.9375rem;
}

.content blockquote strong { color: var(--color-primary); }

.content code {
  background: var(--color-bg-muted);
  padding: 0.175rem 0.45rem;
  border-radius: 4px;
  font-family: var(--font-mono);
  font-size: 0.8125em;
  color: var(--color-primary);
  border: 1px solid var(--color-border);
}

.content pre {
  background: #1e293b;
  color: #e2e8f0;
  padding: 1.25rem 1.5rem;
  border-radius: var(--radius-md);
  overflow-x: auto;
  margin: 1.25rem 0;
  font-size: 0.8125rem;
  line-height: 1.7;
  border: 1px solid #334155;
}

.content pre code {
  background: none;
  padding: 0;
  color: inherit;
  border: none;
  font-size: inherit;
}

.content hr {
  border: none;
  border-top: 1px solid var(--color-border);
  margin: 2.5rem 0;
}

/* === 表格 === */
.content table {
  width: 100%;
  border-collapse: separate;
  border-spacing: 0;
  margin: 1.25rem 0;
  font-size: 0.875rem;
  border-radius: var(--radius-md);
  overflow: hidden;
  border: 1px solid var(--color-border);
}

.content th {
  background: var(--color-bg-muted);
  font-weight: 600;
  text-align: left;
  color: var(--color-text);
  font-size: 0.8125rem;
  text-transform: none;
  letter-spacing: 0;
}

.content th, .content td {
  padding: 0.75rem 1rem;
  border-bottom: 1px solid var(--color-border);
}

.content tr:last-child td { border-bottom: none; }

.content tbody tr {
  transition: background var(--transition);
}

.content tbody tr:hover { background: var(--color-bg-subtle); }

/* === 全宽布局（首页） === */
.layout-full {
  max-width: 900px;
  padding: 0 2rem 3rem;
}

.content-full {
  min-width: 0;
}

/* === 首页 === */
.hero {
  text-align: center;
  padding: 3.5rem 1rem 1.5rem;
}

.hero h1 {
  font-size: 2rem;
  font-weight: 800;
  color: var(--color-text);
  margin-bottom: 0.5rem;
  letter-spacing: -0.03em;
}

.hero-sub {
  color: var(--color-text-muted);
  font-size: 0.9375rem;
  font-weight: 500;
}

/* 分组 */
.section-group {
  margin-bottom: 1.75rem;
}

.section-label {
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--color-text-muted);
  margin-bottom: 0.625rem;
  padding-left: 0.25rem;
}

.card-grid {
  display: grid;
  gap: 0.75rem;
}

.card-grid-2 { grid-template-columns: repeat(2, 1fr); }
.card-grid-3 { grid-template-columns: repeat(3, 1fr); }

.card {
  display: flex;
  flex-direction: column;
  padding: 1.25rem 1.375rem;
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  text-decoration: none;
  color: var(--color-text);
  cursor: pointer;
  transition: box-shadow var(--transition), border-color var(--transition);
}

.card:hover {
  box-shadow: var(--shadow-md);
  border-color: var(--color-primary-border);
}

.card-tag {
  display: inline-block;
  font-size: 0.6875rem;
  font-weight: 700;
  padding: 0.2rem 0.5rem;
  border-radius: 4px;
  margin-bottom: 0.625rem;
  width: fit-content;
  letter-spacing: 0.02em;
}

.tag-red { background: var(--color-primary-soft); color: var(--color-primary); }
.tag-blue { background: var(--color-accent-soft); color: var(--color-accent); }

.card h3 {
  font-size: 0.9375rem;
  font-weight: 700;
  margin-bottom: 0.3rem;
  color: var(--color-text);
}

.card p {
  font-size: 0.8125rem;
  color: var(--color-text-muted);
  line-height: 1.55;
  flex: 1;
}

.card-alert {
  border-color: var(--color-primary-border);
  background: var(--color-primary-soft);
}

.card-alert:hover {
  border-color: var(--color-primary);
}

.team-section {
  margin: 1rem 0 0;
  text-align: center;
  padding: 1.75rem;
  background: var(--color-bg);
  border-radius: var(--radius-md);
  border: 1px dashed var(--color-border);
}

.team-section h2 {
  font-size: 1.125rem;
  font-weight: 700;
  border: none;
  padding: 0;
  margin-bottom: 0.375rem;
  color: var(--color-text);
}

.team-section p {
  color: var(--color-text-muted);
  font-size: 0.875rem;
}

/* === 队伍页面访问控制 === */
.access-denied {
  display: none;
  text-align: center;
  padding: 5rem 1rem;
}

.access-denied-box {
  max-width: 420px;
  margin: 0 auto;
  padding: 2.5rem;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  background: var(--color-bg);
  box-shadow: var(--shadow-md);
}

.access-denied-box::before {
  content: '🔒';
  display: block;
  font-size: 2.5rem;
  margin-bottom: 1rem;
}

.access-denied-box h2 {
  font-size: 1.25rem;
  margin-bottom: 0.75rem;
  border: none;
  padding: 0;
  color: var(--color-text);
}

.access-denied-box p {
  font-size: 0.9rem;
  color: var(--color-text-muted);
  margin-bottom: 0.5rem;
}

.empty-notice {
  color: var(--color-text-muted);
  font-style: italic;
  padding: 2rem 0;
}

/* === Checkbox 列表样式 === */
.content li:has(input[type="checkbox"]) {
  list-style: none;
  margin-left: -1.25rem;
  padding: 0.375rem 0.75rem;
  border-radius: var(--radius-sm);
  transition: background var(--transition);
}

.content li:has(input[type="checkbox"]):hover {
  background: var(--color-bg-subtle);
}

.content input[type="checkbox"] {
  margin-right: 0.5rem;
  accent-color: var(--color-primary);
  width: 16px;
  height: 16px;
  vertical-align: middle;
}

/* === 移动端 === */
@media (max-width: 768px) {
  .nav-toggle { display: flex; align-items: center; }
  .nav-inner { padding: 0 1rem; }

  .nav-links {
    display: none;
    position: absolute;
    top: var(--nav-height);
    left: 0;
    right: 0;
    background: rgba(255,255,255,0.98);
    backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--color-border);
    flex-direction: column;
    padding: 0.75rem;
    box-shadow: var(--shadow-lg);
  }

  .nav-links.open { display: flex; }

  .nav-dropdown-menu {
    position: static;
    box-shadow: none;
    border: none;
    padding-left: 1rem;
    display: none;
    transform: none;
    background: transparent;
  }

  .nav-dropdown.open .nav-dropdown-menu { display: block; }
  .toc { display: none; }
  .layout { padding: 1rem 0.75rem; }

  .content {
    max-width: 100%;
    padding: 1.5rem;
    border-radius: var(--radius-md);
  }

  .layout-full { padding: 0 1rem 2rem; }
  .hero { padding: 2rem 0.5rem 1rem; }
  .hero h1 { font-size: 1.5rem; }
  .card-grid-2, .card-grid-3 { grid-template-columns: 1fr; }

  .content h1 { font-size: 1.5rem; }
  .content h2 { font-size: 1.1875rem; margin-top: 2rem; }

  .content table { font-size: 0.8125rem; }
  .content th, .content td { padding: 0.5rem 0.625rem; }
}

/* 表格横向滚动（小屏） */
@media (max-width: 640px) {
  .content table {
    display: block;
    overflow-x: auto;
    white-space: nowrap;
    -webkit-overflow-scrolling: touch;
  }
}

@media (min-width: 769px) and (max-width: 1024px) {
  .card-grid-3 { grid-template-columns: repeat(2, 1fr); }
}

/* === 打印样式 === */
@media print {
  .top-nav, .toc, .nav-toggle { display: none; }
  .content { box-shadow: none; border: none; padding: 0; max-width: 100%; }
  .layout { padding: 0; }
  body { background: white; }
}