/* ============================================
   ELTA 官网样式 — 极简中文落地页
   参考 vmark.app 设计理念
   ============================================ */

:root {
  --bg:         #fafafa;
  --card:       #ffffff;
  --text:       #1a1a2e;
  --sub:        #6b7280;
  --muted:      #9ca3af;
  --accent:     #2563eb;
  --accent-h:   #1d4ed8;
  --border:     #e5e7eb;
  --code-bg:    #f1f5f9;
  --radius-sm:  6px;
  --radius:     12px;
  --radius-lg:  16px;
  --shadow:     0 1px 3px rgba(0,0,0,0.06), 0 1px 2px rgba(0,0,0,0.04);
  --shadow-md:  0 4px 16px rgba(0,0,0,0.08);
}

/* ---- Reset ---- */
*, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }

body {
  font-family: -apple-system, BlinkMacSystemFont, "SF Pro Display", "SF Pro Text",
               "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.75;
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

a { color: var(--accent); text-decoration: none; }
a:hover { color: var(--accent-h); }
code, kbd {
  font-family: "SF Mono", "Fira Code", "Consolas", monospace;
  font-size: 0.9em;
}
kbd {
  display: inline-block;
  padding: 1px 6px;
  background: var(--code-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  font-size: 0.85em;
  line-height: 1.5;
}

/* ---- Nav ---- */
.nav {
  position: sticky; top: 0; z-index: 100;
  background: rgba(250,250,250,0.85);
  backdrop-filter: blur(20px) saturate(180%);
  -webkit-backdrop-filter: blur(20px) saturate(180%);
  border-bottom: 1px solid var(--border);
}
.nav-inner {
  max-width: 880px; margin: 0 auto;
  padding: 0 24px; height: 56px;
  display: flex; align-items: center; justify-content: space-between;
}
.nav-logo {
  font-size: 19px; font-weight: 700; color: var(--text);
  display: flex; align-items: center; gap: 6px;
}
.logo-icon { font-size: 22px; }
.nav-links { display: flex; gap: 28px; }
.nav-links a {
  font-size: 14px; font-weight: 500; color: var(--sub);
  transition: color 0.15s;
}
.nav-links a:hover, .nav-links a.active { color: var(--accent); }

/* ---- Hero ---- */
.hero {
  text-align: center;
  padding: 70px 24px 60px;
  max-width: 620px; margin: 0 auto;
}
.hero h1 {
  font-size: 46px; font-weight: 800; letter-spacing: -1px;
  margin-bottom: 4px;
}
.hero-subtitle {
  font-size: 20px; font-weight: 500;
  color: var(--sub); margin-bottom: 20px;
}
.hero-desc {
  font-size: 16px; color: var(--sub);
  line-height: 1.8; margin-bottom: 28px;
}

.badge-row {
  display: flex; justify-content: center; gap: 8px;
  flex-wrap: wrap; margin-bottom: 32px;
}
.badge {
  display: inline-flex; align-items: center; gap: 4px;
  padding: 5px 12px; border-radius: 20px;
  font-size: 13px; font-weight: 600;
  background: #eff6ff; color: #1e40af;
}

/* ---- Button ---- */
.btn-primary {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 14px 32px;
  background: var(--accent); color: #fff;
  font-size: 16px; font-weight: 600;
  border-radius: var(--radius);
  transition: background 0.2s, transform 0.15s;
  box-shadow: 0 2px 8px rgba(37,99,235,0.25);
}
.btn-primary:hover { background: var(--accent-h); color: #fff; transform: translateY(-1px); }
.btn-primary:active { transform: translateY(0); }

.version-text {
  margin-top: 14px;
  font-size: 13px; color: var(--muted);
}

/* ---- Section ---- */
.section {
  max-width: 880px; margin: 0 auto;
  padding: 60px 24px;
}
.section-alt { background: var(--card); border-top: 1px solid var(--border); border-bottom: 1px solid var(--border); }

.section-header { text-align: center; margin-bottom: 40px; }
.section-header h2 {
  font-size: 28px; font-weight: 700;
  letter-spacing: -0.3px; margin-bottom: 8px;
}
.section-header p { color: var(--sub); font-size: 16px; }

/* ---- Feature Grid ---- */
.feature-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 20px;
}
.feature-card {
  background: var(--card); border: 1px solid var(--border);
  border-radius: var(--radius); padding: 24px;
  transition: box-shadow 0.2s, border-color 0.2s;
}
.feature-card:hover {
  box-shadow: var(--shadow-md);
  border-color: transparent;
}
.feature-icon { font-size: 28px; margin-bottom: 12px; }
.feature-card h3 {
  font-size: 17px; font-weight: 700; margin-bottom: 8px;
}
.feature-card p {
  font-size: 14px; color: var(--sub); line-height: 1.7;
}

/* ---- Steps ---- */
.steps {
  display: flex; align-items: flex-start; justify-content: center;
  gap: 16px; flex-wrap: wrap;
}
.step {
  flex: 1; min-width: 200px; max-width: 260px;
  text-align: center; padding: 20px;
}
.step-num {
  width: 40px; height: 40px; margin: 0 auto 12px;
  background: var(--accent); color: #fff;
  border-radius: 50%; font-size: 18px; font-weight: 700;
  display: flex; align-items: center; justify-content: center;
}
.step h3 { font-size: 16px; font-weight: 700; margin-bottom: 6px; }
.step p { font-size: 14px; color: var(--sub); }
.step-arrow {
  font-size: 20px; color: var(--muted);
  align-self: center; padding-top: 8px;
}

/* ---- Tech Grid ---- */
.tech-grid {
  display: flex; flex-wrap: wrap; justify-content: center;
  gap: 12px;
}
.tech-item {
  padding: 10px 20px;
  background: var(--card); border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  text-align: center; min-width: 140px;
}
.tech-name { display: block; font-weight: 700; font-size: 14px; }
.tech-desc { display: block; font-size: 12px; color: var(--muted); margin-top: 2px; }

/* ---- Footer ---- */
.footer {
  border-top: 1px solid var(--border);
  padding: 32px 24px;
}
.footer-inner {
  max-width: 880px; margin: 0 auto;
  display: flex; align-items: center; justify-content: space-between;
  flex-wrap: wrap; gap: 12px;
}
.footer-links { display: flex; gap: 20px; }
.footer-links a { font-size: 14px; color: var(--sub); }
.footer-links a:hover { color: var(--accent); }
.footer-copy { font-size: 13px; color: var(--muted); }

/* ============================================
   文档页 (docs.html)
   ============================================ */

.doc-container {
  max-width: 960px; margin: 0 auto;
  padding: 40px 24px 60px;
  display: grid;
  grid-template-columns: 200px 1fr;
  gap: 48px;
}

.doc-sidebar {
  position: sticky; top: 72px;
  align-self: start;
}

.doc-toc h4 {
  font-size: 14px; font-weight: 700;
  color: var(--muted); margin-bottom: 12px;
  text-transform: uppercase; letter-spacing: 0.5px;
}
.doc-toc a {
  display: block;
  padding: 6px 0;
  font-size: 14px; color: var(--sub);
  border-left: 2px solid transparent;
  padding-left: 12px;
  transition: color 0.15s, border-color 0.15s;
}
.doc-toc a:hover, .doc-toc a:target {
  color: var(--accent);
  border-left-color: var(--accent);
}

.doc-main { min-width: 0; }
.doc-main h1 {
  font-size: 32px; font-weight: 800;
  letter-spacing: -0.5px; margin-bottom: 8px;
}
.doc-intro { color: var(--sub); font-size: 16px; margin-bottom: 40px; }

.doc-main h2 {
  font-size: 22px; font-weight: 700;
  margin-top: 48px; margin-bottom: 16px;
  padding-bottom: 8px; border-bottom: 1px solid var(--border);
}
.doc-main h3 {
  font-size: 17px; font-weight: 600;
  margin-top: 24px; margin-bottom: 10px;
}

.doc-main p, .doc-main li {
  font-size: 15px; color: var(--text); line-height: 1.8;
}
.doc-main ul, .doc-main ol {
  padding-left: 24px; margin-bottom: 16px;
}
.doc-main li { margin-bottom: 6px; }

.doc-note {
  background: #f0f9ff; border-left: 3px solid var(--accent);
  border-radius: var(--radius-sm);
  padding: 14px 18px; margin: 16px 0;
  font-size: 14px;
}
.template-note pre {
  margin-top: 10px;
  background: var(--code-bg);
  padding: 12px 16px;
  border-radius: var(--radius-sm);
  font-size: 13px;
  line-height: 1.7;
  overflow-x: auto;
}

.doc-table {
  width: 100%; border-collapse: collapse;
  margin: 12px 0 24px;
  font-size: 14px;
}
.doc-table th, .doc-table td {
  text-align: left; padding: 10px 14px;
  border-bottom: 1px solid var(--border);
}
.doc-table th {
  font-weight: 700; color: var(--sub);
  font-size: 13px; text-transform: uppercase; letter-spacing: 0.3px;
}

/* ---- Responsive ---- */
@media (max-width: 768px) {
  .hero h1 { font-size: 34px; }
  .hero-desc { font-size: 15px; }
  .steps { flex-direction: column; align-items: center; }
  .step-arrow { transform: rotate(90deg); }
  .doc-container { grid-template-columns: 1fr; }
  .doc-sidebar { position: static; }
  .doc-toc { display: flex; flex-wrap: wrap; gap: 8px; }
  .doc-toc a { border-left: none; padding-left: 0; border-bottom: 2px solid transparent; }
  .footer-inner { flex-direction: column; text-align: center; }
}