:root {
  --accent: #3d5aeb;
  --accent-2: #7c5cff;
  --accent-soft: rgba(61, 90, 235, 0.12);
  --bg: #ffffff;
  --bg-soft: #f6f7fb;
  --bg-elevated: #ffffff;
  --text: #0f1222;
  --text-soft: #384066;
  --muted: #5b6480;
  --border: #e5e7f0;
  --header-bg: rgba(255, 255, 255, 0.8);
  --radius: 16px;
  --shadow: 0 12px 32px -16px rgba(20, 30, 80, 0.18);
  --font-sans: -apple-system, BlinkMacSystemFont, "SF Pro Text",
               "Helvetica Neue", "PingFang SC", "Hiragino Sans GB", sans-serif;
  --font-mono: ui-monospace, "SF Mono", Menlo, monospace;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0b0e1a;
    --bg-soft: #12172a;
    --bg-elevated: #161c34;
    --text: #eef1ff;
    --text-soft: #c8cfe8;
    --muted: #9aa3c0;
    --border: #232a45;
    --accent-soft: rgba(124, 92, 255, 0.18);
    --header-bg: rgba(11, 14, 26, 0.8);
    --shadow: 0 12px 32px -16px rgba(0, 0, 0, 0.6);
  }
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  font-family: var(--font-sans);
  background: var(--bg);
  color: var(--text);
  line-height: 1.65;
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
}

.container {
  max-width: 1080px;
  margin: 0 auto;
  padding: 0 24px;
}

/* 页头 */
.site-header {
  position: sticky;
  top: 0;
  z-index: 40;
  backdrop-filter: saturate(180%) blur(20px);
  -webkit-backdrop-filter: saturate(180%) blur(20px);
  background: var(--header-bg);
  border-bottom: 1px solid var(--border);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  color: var(--text);
  text-decoration: none;
  font-weight: 700;
  letter-spacing: -0.01em;
}

.brand-mark {
  display: inline-grid;
  place-items: center;
  width: 32px;
  height: 32px;
  border-radius: 10px;
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  color: white;
  font-size: 15px;
}

.site-nav {
  display: flex;
  gap: 22px;
  font-size: 15px;
}

.site-nav a {
  color: var(--muted);
  text-decoration: none;
  transition: color 0.15s ease;
}

.site-nav a:hover,
.site-nav a.active { color: var(--text); }

/* 内容 */
.content {
  padding: 48px 0 80px;
  min-height: 60vh;
}

.content h1 {
  font-size: 2.4rem;
  line-height: 1.15;
  letter-spacing: -0.02em;
  margin: 0 0 16px;
}

.content h2 {
  font-size: 1.65rem;
  letter-spacing: -0.015em;
  margin: 56px 0 18px;
}

.content h3 {
  font-size: 1.1rem;
  margin: 24px 0 8px;
}

.content p {
  margin: 0 0 16px;
  color: var(--text-soft);
}

.content ul, .content ol { color: var(--text-soft); }

.content a { color: var(--accent); text-decoration: none; }
.content a:hover { text-decoration: underline; }

.content blockquote {
  margin: 20px 0;
  padding: 14px 18px;
  border-left: 3px solid var(--accent);
  background: var(--bg-soft);
  border-radius: 0 10px 10px 0;
  color: var(--muted);
}

.content table {
  width: 100%;
  border-collapse: collapse;
  margin: 18px 0;
  font-size: 15px;
}

.content th,
.content td {
  padding: 10px 12px;
  border-bottom: 1px solid var(--border);
  text-align: left;
}

.content th {
  font-weight: 600;
  color: var(--text);
  background: var(--bg-soft);
}

.content code {
  font-family: var(--font-mono);
  background: var(--bg-soft);
  padding: 2px 6px;
  border-radius: 5px;
  font-size: 0.9em;
}

/* Hero */
.hero {
  text-align: center;
  padding: 32px 0 8px;
}

.hero .pill {
  display: inline-block;
  padding: 6px 14px;
  border-radius: 999px;
  background: var(--accent-soft);
  color: var(--accent);
  font-size: 13px;
  font-weight: 600;
  margin-bottom: 20px;
}

.hero h1 {
  font-size: clamp(2.1rem, 5vw, 3.3rem);
  line-height: 1.1;
  letter-spacing: -0.025em;
  margin: 0 0 20px;
}

.hero .lead {
  font-size: 1.1rem;
  max-width: 640px;
  margin: 0 auto 28px;
  color: var(--muted);
}

.cta {
  display: flex;
  gap: 12px;
  justify-content: center;
  flex-wrap: wrap;
  margin-bottom: 28px;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 13px 22px;
  border-radius: 12px;
  font-weight: 600;
  font-size: 15px;
  text-decoration: none;
  border: 1px solid var(--border);
  color: var(--text);
  background: var(--bg-elevated);
  transition: transform 0.15s ease, box-shadow 0.15s ease;
}

.btn:hover {
  transform: translateY(-1px);
  box-shadow: var(--shadow);
  text-decoration: none;
}

.btn.primary {
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  border-color: transparent;
  color: white;
}

.hero-meta {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 10px 22px;
  list-style: none;
  padding: 0;
  margin: 0;
  color: var(--muted);
  font-size: 14px;
}

/* 功能卡片 */
.features {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
  gap: 16px;
  margin-top: 8px;
}

.card {
  padding: 22px;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  background: var(--bg-elevated);
  transition: transform 0.15s ease, box-shadow 0.15s ease;
}

.card:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow);
}

.card-icon { font-size: 26px; margin-bottom: 10px; }

.card h3 { margin: 0 0 6px; font-size: 1rem; }

.card p {
  margin: 0;
  font-size: 14px;
  color: var(--muted);
}

/* 格式徽章 */
.formats {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 8px;
}

.formats span {
  padding: 6px 12px;
  border-radius: 999px;
  background: var(--bg-soft);
  border: 1px solid var(--border);
  font-size: 13px;
  font-family: var(--font-mono);
  color: var(--text-soft);
}

/* 页脚 */
.site-footer {
  border-top: 1px solid var(--border);
  background: var(--bg-soft);
  padding: 28px 0;
}

.footer-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 10px;
  font-size: 14px;
  color: var(--muted);
}

.footer-inner p { margin: 0; }
.muted { color: var(--muted); }