/* ========== 全局基础 ========== */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

:root {
  --primary: #6366f1;
  --primary-light: #818cf8;
  --primary-dark: #4f46e5;
  --bg: #0f172a;
  --bg-card: #1e293b;
  --bg-card-hover: #334155;
  --text: #e2e8f0;
  --text-muted: #94a3b8;
  --border: #334155;
  --accent-green: #34d399;
  --accent-blue: #38bdf8;
  --accent-purple: #a78bfa;
  --accent-pink: #f472b6;
  --accent-orange: #fb923c;
  --radius: 16px;
  --shadow: 0 4px 24px rgba(0, 0, 0, 0.3);
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  min-height: 100vh;
}

a {
  color: var(--primary-light);
  text-decoration: none;
  transition: color 0.2s;
}

a:hover {
  color: var(--accent-blue);
}

/* ========== 导航栏 ========== */
.navbar {
  background: rgba(15, 23, 42, 0.85);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
  padding: 0 2rem;
  height: 64px;
  display: flex;
  align-items: center;
  position: sticky;
  top: 0;
  z-index: 100;
}

.navbar .logo {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--text);
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.navbar .logo span {
  background: linear-gradient(135deg, var(--primary-light), var(--accent-blue));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.navbar nav {
  margin-left: auto;
  display: flex;
  gap: 1.5rem;
}

.navbar nav a {
  color: var(--text-muted);
  font-size: 0.9rem;
  padding: 0.4rem 0;
  border-bottom: 2px solid transparent;
  transition: all 0.2s;
}

.navbar nav a:hover,
.navbar nav a.active {
  color: var(--text);
  border-bottom-color: var(--primary-light);
}

/* ========== 首页 Hero ========== */
.hero {
  text-align: center;
  padding: 5rem 2rem 3rem;
  background: radial-gradient(ellipse at 50% 0%, rgba(99, 102, 241, 0.15) 0%, transparent 60%);
}

.hero h1 {
  font-size: 3rem;
  font-weight: 800;
  margin-bottom: 1rem;
  background: linear-gradient(135deg, #fff 0%, var(--primary-light) 50%, var(--accent-blue) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero p {
  font-size: 1.2rem;
  color: var(--text-muted);
  max-width: 600px;
  margin: 0 auto;
}

/* ========== 卡片网格 ========== */
.cards-section {
  max-width: 1100px;
  margin: 0 auto;
  padding: 2rem 2rem 4rem;
}

.cards-section h2 {
  font-size: 1.5rem;
  margin-bottom: 1.5rem;
  color: var(--text);
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.cards-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: 1.5rem;
}

.card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 2rem;
  transition: all 0.3s ease;
  cursor: pointer;
  position: relative;
  overflow: hidden;
}

.card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--primary-light), var(--accent-blue));
  opacity: 0;
  transition: opacity 0.3s;
}

.card:hover {
  background: var(--bg-card-hover);
  border-color: var(--primary);
  transform: translateY(-4px);
  box-shadow: var(--shadow);
}

.card:hover::before {
  opacity: 1;
}

.card .icon {
  width: 48px;
  height: 48px;
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  margin-bottom: 1rem;
}

.card h3 {
  font-size: 1.2rem;
  margin-bottom: 0.5rem;
  color: var(--text);
}

.card p {
  font-size: 0.9rem;
  color: var(--text-muted);
  line-height: 1.7;
}

.card .tag {
  display: inline-block;
  margin-top: 1rem;
  padding: 0.25rem 0.75rem;
  border-radius: 999px;
  font-size: 0.75rem;
  font-weight: 500;
}

/* 不同卡片颜色 */
.card.purple .icon { background: rgba(167, 139, 250, 0.15); color: var(--accent-purple); }
.card.purple .tag { background: rgba(167, 139, 250, 0.15); color: var(--accent-purple); }

.card.blue .icon { background: rgba(56, 189, 248, 0.15); color: var(--accent-blue); }
.card.blue .tag { background: rgba(56, 189, 248, 0.15); color: var(--accent-blue); }

.card.green .icon { background: rgba(52, 211, 153, 0.15); color: var(--accent-green); }
.card.green .tag { background: rgba(52, 211, 153, 0.15); color: var(--accent-green); }

.card.pink .icon { background: rgba(244, 114, 182, 0.15); color: var(--accent-pink); }
.card.pink .tag { background: rgba(244, 114, 182, 0.15); color: var(--accent-pink); }

.card.orange .icon { background: rgba(251, 146, 60, 0.15); color: var(--accent-orange); }
.card.orange .tag { background: rgba(251, 146, 60, 0.15); color: var(--accent-orange); }

/* ========== 子页面内容 ========== */
.page-content {
  max-width: 900px;
  margin: 0 auto;
  padding: 3rem 2rem 4rem;
}

.page-content h1 {
  font-size: 2.2rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
  background: linear-gradient(135deg, #fff, var(--primary-light));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.page-content .subtitle {
  color: var(--text-muted);
  font-size: 1.1rem;
  margin-bottom: 2.5rem;
}

.page-content h2 {
  font-size: 1.4rem;
  color: var(--text);
  margin: 2.5rem 0 1rem;
  padding-bottom: 0.5rem;
  border-bottom: 1px solid var(--border);
}

.page-content h3 {
  font-size: 1.1rem;
  color: var(--text);
  margin: 1.5rem 0 0.75rem;
}

.page-content p {
  color: var(--text-muted);
  margin-bottom: 1rem;
  line-height: 1.8;
}

.page-content ul, .page-content ol {
  color: var(--text-muted);
  padding-left: 1.5rem;
  margin-bottom: 1rem;
}

.page-content li {
  margin-bottom: 0.5rem;
  line-height: 1.7;
}

.page-content code {
  background: rgba(99, 102, 241, 0.1);
  color: var(--primary-light);
  padding: 0.15rem 0.4rem;
  border-radius: 4px;
  font-size: 0.9em;
}

.page-content pre {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 1.25rem;
  overflow-x: auto;
  margin-bottom: 1.5rem;
}

.page-content pre code {
  background: none;
  padding: 0;
  color: var(--text);
}

.info-box {
  background: rgba(99, 102, 241, 0.08);
  border: 1px solid rgba(99, 102, 241, 0.2);
  border-radius: 12px;
  padding: 1.25rem;
  margin: 1.5rem 0;
}

.info-box h4 {
  color: var(--primary-light);
  margin-bottom: 0.5rem;
  font-size: 0.95rem;
}

.info-box p {
  margin-bottom: 0;
}

/* ========== 表格样式 ========== */
.page-content table {
  width: 100%;
  border-collapse: collapse;
  margin: 1.5rem 0;
  font-size: 0.9rem;
}

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

.page-content th {
  background: rgba(99, 102, 241, 0.08);
  color: var(--text);
  font-weight: 600;
  white-space: nowrap;
}

.page-content td {
  color: var(--text-muted);
}

.page-content tbody tr:hover {
  background: rgba(99, 102, 241, 0.04);
}

/* ========== 子页面内卡片网格 ========== */
.page-content .cards-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
  gap: 1.25rem;
  margin: 1.5rem 0;
}

.page-content .card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.5rem;
  transition: all 0.3s ease;
}

.page-content .card:hover {
  border-color: var(--primary);
  transform: translateY(-2px);
  box-shadow: var(--shadow);
}

.page-content .card h3 {
  margin: 0 0 0.5rem;
  font-size: 1rem;
}

.page-content .card p {
  font-size: 0.85rem;
  margin-bottom: 0;
  line-height: 1.6;
}

/* ========== 页脚 ========== */
.footer {
  text-align: center;
  padding: 2rem;
  color: var(--text-muted);
  font-size: 0.85rem;
  border-top: 1px solid var(--border);
}

/* ========== 响应式 ========== */
@media (max-width: 768px) {
  .hero h1 { font-size: 2rem; }
  .hero p { font-size: 1rem; }
  .cards-grid { grid-template-columns: 1fr; }
  .page-content h1 { font-size: 1.8rem; }
  .page-content .cards-grid { grid-template-columns: 1fr; }
  .page-content table { font-size: 0.8rem; }
  .page-content th, .page-content td { padding: 0.5rem; }
  .navbar nav { gap: 0.75rem; }
  .navbar nav a { font-size: 0.8rem; }
}