:root {
  --bg: #f6f7f9;
  --panel: #ffffff;
  --text: #121826;
  --muted: #5b6578;
  --line: #e6e9ef;
  --primary: #1f6feb;
  --primary-2: #1158c7;
  --sidebar: #0f172a;
  --sidebar-text: #cbd5e1;
  --radius: 12px;
  --container: 1120px;
  --font: "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
}
* { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  line-height: 1.65;
  font-size: 15px;
}
a { color: var(--primary); text-decoration: none; }
a:hover { text-decoration: underline; }
.container { width: min(100% - 32px, var(--container)); margin: 0 auto; }

.header {
  position: sticky; top: 0; z-index: 40;
  background: rgba(255,255,255,0.92);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--line);
}
.header-inner { display: flex; align-items: center; justify-content: space-between; min-height: 60px; gap: 12px; }
.logo { display: inline-flex; align-items: center; gap: 10px; color: var(--text); font-weight: 700; }
.logo:hover { text-decoration: none; }
.logo-mark {
  width: 30px; height: 30px; border-radius: 8px;
  display: grid; place-items: center; background: #0f172a; color: #fff; font-size: 11px;
}
.nav { display: flex; flex-wrap: wrap; gap: 14px; }
.nav a { color: var(--muted); }
.nav a.active, .nav a:hover { color: var(--text); text-decoration: none; }
.nav-toggle { display: none; background: none; border: 0; width: 40px; height: 40px; flex-direction: column; justify-content: center; gap: 5px; cursor: pointer; }
.nav-toggle span { display: block; height: 2px; background: var(--text); }

.btn {
  display: inline-flex; align-items: center; justify-content: center;
  padding: 9px 16px; border-radius: 8px; font-weight: 600; font-size: 0.92rem;
  border: 0; cursor: pointer; text-decoration: none !important;
}
.btn-primary { background: var(--primary); color: #fff; }
.btn-primary:hover { background: var(--primary-2); }
.btn-outline { background: #fff; color: var(--text); border: 1px solid var(--line); }
.btn-lg { padding: 12px 20px; }

.hero {
  padding: 48px 0 28px;
  background:
    radial-gradient(700px 280px at 10% -20%, #dbeafe 0%, transparent 60%),
    linear-gradient(180deg, #fff 0%, var(--bg) 100%);
  border-bottom: 1px solid var(--line);
}
.hero-grid { display: grid; grid-template-columns: 1.2fr 0.8fr; gap: 28px; align-items: center; }
.eyebrow { color: var(--primary); font-size: 0.85rem; font-weight: 600; margin-bottom: 10px; }
.hero h1 { font-size: clamp(1.7rem, 3.4vw, 2.5rem); line-height: 1.25; margin-bottom: 12px; }
.hero-desc { color: var(--muted); max-width: 36em; margin-bottom: 18px; }
.hero-actions { display: flex; flex-wrap: wrap; gap: 10px; }
.hero-card {
  background: var(--panel); border: 1px solid var(--line); border-radius: 16px;
  padding: 18px; box-shadow: 0 10px 30px rgba(15,23,42,0.06);
}
.hero-card h3 { margin-bottom: 10px; font-size: 1rem; }
.hero-card ol { padding-left: 1.2em; color: var(--muted); }
.hero-card li { margin-bottom: 6px; }

.layout {
  display: grid; grid-template-columns: 240px 1fr; gap: 22px;
  padding: 28px 0 48px;
}
.sidebar {
  position: sticky; top: 76px; align-self: start;
  background: var(--panel); border: 1px solid var(--line); border-radius: 14px;
  padding: 14px;
}
.sidebar-title { font-size: 0.78rem; color: var(--muted); text-transform: uppercase; letter-spacing: 0.04em; margin: 8px 0 6px; }
.sidebar a {
  display: block; padding: 8px 10px; border-radius: 8px; color: var(--text); font-size: 0.92rem;
}
.sidebar a:hover, .sidebar a.active { background: #eff6ff; color: var(--primary); text-decoration: none; }

.panel {
  background: var(--panel); border: 1px solid var(--line); border-radius: 14px;
  padding: 24px 28px 32px;
}
.breadcrumb { color: var(--muted); font-size: 0.85rem; margin-bottom: 14px; }
.article-body h1 { font-size: 1.7rem; margin-bottom: 12px; }
.article-body h2 { font-size: 1.2rem; margin: 1.4em 0 0.55em; }
.article-body h3 { font-size: 1.05rem; margin: 1.1em 0 0.4em; }
.article-body p, .article-body li { margin-bottom: 0.7em; color: #334155; }
.article-body ul, .article-body ol { padding-left: 1.25em; margin-bottom: 1em; }
.article-meta { color: var(--muted) !important; font-size: 0.85rem; }
.article-cta {
  margin-top: 1.5rem; padding: 16px; border-radius: 12px;
  background: #eff6ff; border: 1px solid #bfdbfe;
}
.related-posts { margin-top: 1.4rem; padding-top: 1rem; border-top: 1px solid var(--line); }
.related-posts h2 { font-size: 1.05rem; margin-bottom: 8px; }
.back-link { margin-top: 18px; font-size: 0.9rem; }

.feature-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 12px; margin-top: 16px; }
.feature-card {
  display: block; background: var(--panel); border: 1px solid var(--line);
  border-radius: 12px; padding: 16px; color: inherit;
}
.feature-card:hover { border-color: #93c5fd; text-decoration: none; }
.feature-card h3 { margin-bottom: 6px; font-size: 1rem; }
.feature-card p { color: var(--muted); font-size: 0.9rem; }

.download-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 12px; margin-top: 14px; }
.download-card {
  display: block; border: 1px solid var(--line); border-radius: 12px; padding: 16px;
  background: #fff; color: inherit; text-align: center;
}
.download-card:hover { border-color: #93c5fd; text-decoration: none; }
.download-card h3 { margin: 8px 0 4px; }
.download-card p { color: var(--muted); font-size: 0.85rem; }

.blog-list { list-style: none; }
.blog-item { padding: 14px 0; border-bottom: 1px solid var(--line); }
.blog-date { display: block; color: var(--muted); font-size: 0.8rem; margin: 4px 0; }
.faq-item { background: #f8fafc; border: 1px solid var(--line); border-radius: 10px; padding: 12px 14px; margin-bottom: 8px; }
.faq-item summary { cursor: pointer; font-weight: 600; }
.faq-item p { margin-top: 8px; color: var(--muted); }

.footer {
  margin-top: 12px; padding: 36px 0 20px; background: #0f172a; color: #94a3b8; font-size: 0.9rem;
}
.footer a { color: #bfdbfe; }
.footer-grid { display: grid; grid-template-columns: 1.5fr 1fr 1fr 1fr; gap: 18px; margin-bottom: 18px; }
.footer-col { display: flex; flex-direction: column; gap: 6px; }
.footer-col strong { color: #fff; margin-bottom: 4px; }
.footer-bottom { border-top: 1px solid rgba(255,255,255,0.08); padding-top: 12px; font-size: 0.82rem; }
.error-page { min-height: 50vh; display: grid; place-content: center; text-align: center; gap: 12px; }

@media (max-width: 900px) {
  .nav-toggle { display: flex; }
  .nav, .header-actions { display: none; }
  .header-inner.nav-open .nav {
    display: flex; flex-direction: column; position: absolute; left: 0; right: 0; top: 60px;
    background: #fff; padding: 12px 16px; gap: 10px; border-bottom: 1px solid var(--line);
  }
  .hero-grid, .layout, .feature-grid, .download-grid, .footer-grid { grid-template-columns: 1fr; }
  .sidebar { position: static; }
  .panel { padding: 18px 16px 24px; }
}