/* 基础重置与可访问性 */
:root { --bg:#0b1220; --bg-elev:#0e1626; --text:#e6edf3; --muted:#9fb3c8; --brand:#0ea5e9; --brand-600:#0284c7; --card:#111a2b; --border:#203047; --ok:#10b981; }
@media (prefers-color-scheme: light){ :root{ --bg:#ffffff; --bg-elev:#f7fbff; --text:#0b1220; --muted:#475569; --card:#f8fafc; --border:#e2e8f0; } }
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin:0; font-family: ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, Noto Sans, Ubuntu, Cantarell, Helvetica Neue, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "WenQuanYi Micro Hei", sans-serif; background: var(--bg); color:var(--text); line-height:1.6; }
a { color: inherit; text-decoration: none; }
a:focus-visible, button:focus-visible { outline:2px solid var(--brand); outline-offset:2px; }
img { max-width:100%; height:auto; display:block; }

/* 布局 */
.container { width:100%; max-width:1120px; margin:0 auto; padding:0 20px; }
.site-header { position:sticky; top:0; z-index:50; background:rgba(11,18,32,0.8); backdrop-filter:saturate(180%) blur(10px); border-bottom:1px solid var(--border); }
@media (prefers-color-scheme: light){ .site-header{ background:rgba(255,255,255,0.8);} }
.header-inner { display:flex; align-items:center; justify-content:space-between; min-height:64px; }
.brand { display:flex; align-items:center; gap:12px; font-weight:700; }
.brand img { filter: drop-shadow(0 2px 8px rgba(14,165,233,.35)); }
.brand-text { letter-spacing:.3px; }
.site-nav { display:flex; gap:20px; }
.site-nav a { color:var(--muted); padding:10px 12px; border-radius:8px; }
.site-nav a:hover { color:var(--text); background:var(--bg-elev); }

.hero { padding:64px 0 32px; background: radial-gradient(1200px 400px at 20% -10%, rgba(14,165,233,.25), transparent), radial-gradient(800px 300px at 100% 0%, rgba(16,185,129,.2), transparent); border-bottom:1px solid var(--border); }
.hero-inner { display:grid; grid-template-columns: 1.1fr 0.9fr; gap:32px; align-items:center; }
.hero-copy h1 { font-size: clamp(28px, 4vw, 44px); line-height:1.2; margin:0 0 12px; }
.subtitle { color:var(--muted); margin:0 0 24px; }
.cta-group { display:flex; gap:12px; flex-wrap:wrap; }
.btn { display:inline-flex; align-items:center; justify-content:center; padding:12px 18px; border-radius:12px; border:1px solid var(--border); transition: all .2s ease; font-weight:600; }
.btn-primary { background: linear-gradient(180deg, var(--brand), var(--brand-600)); color:white; border:none; box-shadow: 0 10px 20px rgba(2,132,199,.25); }
.btn-primary:hover { transform: translateY(-1px); box-shadow: 0 14px 28px rgba(2,132,199,.35); }
.btn-secondary { background: var(--bg-elev); color:var(--text); }
.btn-secondary:hover { background: #152239; }
.trust { color:var(--muted); margin-top:10px; font-size:14px; }
.hero-art { display:flex; justify-content:center; }

.download { padding:48px 0; }
.download h2, .features h2, .faq h2 { font-size: clamp(22px, 3vw, 28px); margin:0 0 20px; }
.platforms { display:grid; grid-template-columns: repeat(3, 1fr); gap:16px; }
.card { background:var(--card); border:1px solid var(--border); border-radius:14px; transition: transform .15s ease, box-shadow .15s ease; }
.card:hover { transform: translateY(-2px); box-shadow: 0 10px 22px rgba(2,12,27,.35); }
.card-body { padding:18px; }
.card-title { font-weight:700; margin-bottom:6px; }
.card-desc { color:var(--muted); font-size:14px; }
.note { color:var(--muted); margin-top:16px; font-size:14px; }

.features { padding:24px 0 8px; }
.feature-grid { display:grid; grid-template-columns: repeat(3, 1fr); gap:16px; }
.feature { background:var(--bg-elev); border:1px solid var(--border); border-radius:14px; padding:18px; }

.faq { padding:24px 0 48px; }
details { background:var(--bg-elev); border:1px solid var(--border); border-radius:12px; padding:14px 16px; margin-bottom:12px; }
summary { cursor:pointer; font-weight:600; }

.site-footer { border-top:1px solid var(--border); padding:20px 0; }
.footer-inner { display:flex; align-items:center; justify-content:space-between; gap:12px; color:var(--muted); font-size:14px; }
.footer-links { display:flex; gap:12px; }

/* 响应式 */
@media (max-width: 960px){
  .hero-inner { grid-template-columns: 1fr; }
  .platforms, .feature-grid { grid-template-columns: 1fr; }
}

/* 打印优化 */
@media print{
  .site-header, .hero-art, .cta-group { display:none !important; }
  a::after { content: " (" attr(href) ")"; color:#666; }
}