/* 基础主题变量 */
:root {
  --bg: #0f1223;
  --surface: #151a33;
  --surface-2: #11152a;
  --text: #e6e9ff;
  --muted: #a9b0d9;
  --primary: #7c5cff;
  --primary-2: #5a3cff;
  --secondary: #1f9dff;
  --accent: #18c29c;
  --card: #171b35;
  --border: #2a315b;
  --shadow: 0 10px 30px rgba(0,0,0,0.35);
}

/* 亮色模式（可切换） */
html[data-theme="light"] {
  --bg: #f8f9ff;
  --surface: #ffffff;
  --surface-2: #f0f3ff;
  --text: #1b1e38;
  --muted: #51608f;
  --primary: #5a3cff;
  --primary-2: #4a2bff;
  --secondary: #0b78e3;
  --accent: #0aa57f;
  --card: #ffffff;
  --border: #dde3ff;
}

* { box-sizing: border-box; }
html, body { height: 100%; }
body {
  margin: 0;
  font-family: ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, Helvetica, Arial, "PingFang SC", "Microsoft YaHei", sans-serif;
  color: var(--text);
  background: radial-gradient(1200px 600px at 20% -10%, rgba(92,71,255,0.25), transparent 60%),
              radial-gradient(800px 400px at 100% 0%, rgba(31,157,255,0.18), transparent 50%),
              var(--bg);
  line-height: 1.7;
}

.container { width: min(1100px, 92%); margin: 0 auto; }

/* 头部导航 */
.site-header { position: sticky; top: 0; backdrop-filter: blur(10px); z-index: 20; border-bottom: 1px solid var(--border); background: color-mix(in oklab, var(--bg) 80%, transparent); }
.header-inner { display: flex; align-items: center; justify-content: space-between; padding: 14px 0; }
.logo { font-weight: 800; letter-spacing: 0.5px; color: var(--text); text-decoration: none; font-size: 20px; }
.nav { display: flex; gap: 14px; }
.nav-link { color: var(--muted); text-decoration: none; padding: 8px 10px; border-radius: 8px; }
.nav-link:hover { color: var(--text); background: var(--surface-2); }
.nav-link.active { color: #fff; background: var(--primary); }

.btn { display: inline-flex; align-items: center; gap: 8px; border: 1px solid var(--border); color: var(--text); background: var(--surface-2); padding: 10px 14px; border-radius: 12px; text-decoration: none; box-shadow: var(--shadow); }
.btn:hover { transform: translateY(-1px); background: var(--surface); }
.btn-primary { background: var(--primary); border-color: transparent; }
.btn-primary:hover { background: var(--primary-2); }
.btn-secondary { background: var(--secondary); border-color: transparent; }
.btn-ghost { background: transparent; border-color: var(--border); }

/* 首屏 */
.hero { padding: 72px 0; }
.hero-title { font-size: clamp(28px, 4vw, 44px); margin: 0 0 10px; }
.hero-subtitle { margin: 0 0 18px; color: var(--muted); }
.hero-actions { display: flex; gap: 12px; }

/* 页面通用分区 */
.section { padding: 40px 0; }
.section.alt { background: var(--surface-2); border-top: 1px solid var(--border); border-bottom: 1px solid var(--border); }
.section-head { display: flex; align-items: baseline; justify-content: space-between; margin-bottom: 16px; }
.link { color: var(--secondary); text-decoration: none; }
.link:hover { text-decoration: underline; }

/* 卡片与网格 */
.grid { display: grid; gap: 16px; }
.cards { grid-template-columns: repeat(auto-fill, minmax(260px, 1fr)); }
.card { background: var(--card); border: 1px solid var(--border); border-radius: 16px; overflow: hidden; box-shadow: var(--shadow); }
.card-body { display: block; color: inherit; text-decoration: none; padding: 18px; }
.card-meta { font-size: 13px; color: var(--muted); margin-bottom: 6px; }
.card-title { margin: 0 0 8px; font-size: 18px; }
.card-desc { margin: 0; color: var(--muted); }

/* 页面标题区 */
.page-hero { padding: 36px 0; border-bottom: 1px solid var(--border); background: var(--surface-2); }
.page-hero h1 { margin: 0 0 8px; }

/* 双列布局 */
.two-cols { grid-template-columns: 1fr 1fr; }
.list { margin: 6px 0 18px; padding-left: 18px; }

/* 文章正文 */
.post { padding: 30px 0; }
.post-header { margin-bottom: 16px; }
.post-title { margin: 0 0 8px; font-size: clamp(24px, 3.2vw, 32px); }
.post-meta { color: var(--muted); font-size: 14px; }
.post-content h2 { margin-top: 22px; }
.post-content p { margin: 12px 0; }
.post-content code { background: var(--surface-2); padding: 2px 6px; border-radius: 6px; }

/* 页脚 */
.site-footer { border-top: 1px solid var(--border); background: var(--surface-2); }
.footer-inner { padding: 18px 0; display: flex; align-items: center; justify-content: space-between; color: var(--muted); }
.footer-links { display: flex; gap: 12px; }
.footer-links a { color: var(--muted); text-decoration: none; }
.footer-links a:hover { color: var(--text); }

/* 页脚备案信息 */
.beian { text-align: center; padding: 8px 0 20px; font-size: 13px; color: var(--muted); }
.beian p { margin: 0; }
.beian img { width: 20px; height: 20px; vertical-align: -4px; margin-right: 6px; border-radius: 50%; box-shadow: 0 0 0 1px var(--border), 0 2px 6px rgba(0,0,0,0.3); }
.beian a { color: var(--muted); text-decoration: none; border-bottom: 1px dashed var(--border); }
.beian a:hover { color: var(--text); border-bottom-color: var(--accent); }

/* 响应式 */
@media (max-width: 820px) {
  .two-cols { grid-template-columns: 1fr; }
  .header-inner { padding: 12px 0; }
}