/* === 基础主题（白色 + 霓虹点缀）=== */
:root {
  --bg: #ffffff;
  --text: #0a0a0a;
  --muted: #667085;
  --border: #eaeef2;
  --accent-1: #4F46E5; /* indigo */
  --accent-2: #06B6D4; /* cyan */
  --accent-3: #A855F7; /* violet */
}
html { color-scheme: light; }
* { box-sizing: border-box; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 400 16px/1.6 "Inter", "SF Pro Text", "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
}
img { display: block; max-width: 100%; height: auto; }
a { color: var(--text); text-decoration: none; }
.container { width: min(1120px, 92vw); margin-inline: auto; }
.skip { position: absolute; left: -9999px; }
.skip:focus { left: 16px; top: 16px; background: #fff; color: #000; padding: 8px 12px; border-radius: 8px; }

/* === 顶部导航 === */
.site-header {
  position: sticky; top: 0; z-index: 50;
  backdrop-filter: saturate(1.2) blur(10px);
  background: rgba(255,255,255,0.7);
  border-bottom: 1px solid var(--border);
}
.nav { display: flex; align-items: center; justify-content: space-between; padding: 12px 0; }
.brand { display: flex; align-items: center; gap: 10px; font-weight: 700; }
.nav-links { display: flex; align-items: center; gap: 22px; }
.nav-links a { position: relative; padding: 8px 10px; }
.nav-links a::after { content: ""; position: absolute; left: 0; right: 0; bottom: -2px; height: 2px; border-radius: 2px; transform: scaleX(0); transform-origin: left; transition: transform .25s ease; background: linear-gradient(90deg, var(--accent-1), var(--accent-2), var(--accent-3)); }
.nav-links a:hover::after { transform: scaleX(1); }
.nav-toggle { display: none; font-size: 20px; border: 1px solid var(--border); background: #fff; padding: 6px 10px; border-radius: 8px; }
.cta { border: 1px solid var(--border); padding: 8px 14px; border-radius: 999px; background: #fff; box-shadow: 0 0 0 0 rgba(79,70,229,.0); transition: box-shadow .25s ease; }
.cta:hover { box-shadow: 0 0 0 6px rgba(79,70,229,.12), 0 8px 24px rgba(79,70,229,.18); }

@media (max-width: 920px) {
  .nav-toggle { display: inline-block; }
  .nav-links { position: fixed; inset: 64px 0 auto 0; background: rgba(255,255,255,.95); backdrop-filter: blur(8px); border-bottom: 1px solid var(--border); padding: 12px 16px; display: none; flex-direction: column; gap: 12px; }
  .nav-links.open { display: flex; }
}

/* === 英雄区 === */
.hero { position: relative; overflow: hidden; }
.hero-bg {
  position: absolute; inset: -20% -10%; pointer-events: none;
  background:
    radial-gradient(1200px 600px at 10% 20%, rgba(79,70,229,.16), transparent 60%),
    radial-gradient(1000px 500px at 90% 10%, rgba(6,182,212,.14), transparent 60%),
    radial-gradient(900px 500px at 50% 90%, rgba(168,85,247,.14), transparent 60%);
  filter: blur(20px) saturate(1.2);
  animation: glow 14s linear infinite;
}
html.reduced-motion .hero-bg { animation: none; }
@keyframes glow {
  0%   { transform: translateY(0) scale(1); }
  50%  { transform: translateY(-6px) scale(1.02); }
  100% { transform: translateY(0) scale(1); }
}
.hero-inner { position: relative; padding: clamp(48px, 8vw, 120px) 0; display: grid; grid-template-columns: 1.1fr .9fr; gap: 32px; align-items: center; }
.hero h1 { font-size: clamp(28px, 5vw, 56px); line-height: 1.1; letter-spacing: -0.02em; margin: 0; }
.accent { background: linear-gradient(90deg, var(--accent-1), var(--accent-2), var(--accent-3)); -webkit-background-clip: text; background-clip: text; color: transparent; }
.sub { color: var(--muted); font-size: clamp(14px, 2.2vw, 18px); max-width: 64ch; }
.actions { display: flex; gap: 14px; margin: 18px 0 8px; }
.btn { display: inline-flex; align-items: center; gap: 8px; padding: 12px 18px; border-radius: 14px; font-weight: 600; }
.btn.primary { color: #fff; background: linear-gradient(90deg, var(--accent-1), var(--accent-2)); box-shadow: 0 10px 28px rgba(79,70,229,.25); }
.btn.ghost { border: 1px solid var(--border); }
.hero-illus { margin: 0; }
.hero-illus img { border-radius: 18px; border: 1px solid var(--border); box-shadow: 0 30px 60px rgba(10,10,10,.08); }

@media (max-width: 920px) {
  .hero-inner { grid-template-columns: 1fr; }
}

/* === 三大卖点卡片 === */
.features { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; padding: 32px 0; }
.card { border: 1px solid var(--border); border-radius: 16px; padding: 18px; background: #fff; box-shadow: 0 10px 30px rgba(10,10,10,.04); transition: transform .2s ease, box-shadow .2s ease; }
.card:hover { transform: translateY(-2px); box-shadow: 0 16px 40px rgba(79,70,229,.12); }
.card .icon { font-size: 24px; }
.card h3 { margin: 8px 0; }
.card p { color: var(--muted); margin: 0; }
@media (max-width: 920px) { .features { grid-template-columns: 1fr; } }

/* === 展示区 === */
.showcase { display: grid; grid-template-columns: repeat(4, 1fr); gap: 18px; padding: 8px 0 40px; }
.tile { border: 1px solid var(--border); border-radius: 16px; overflow: hidden; background: #fff; box-shadow: 0 14px 40px rgba(10,10,10,.05); }
.tile img { aspect-ratio: 16/10; width: 100%; }
.tile h4 { margin: 12px; }
.tile:hover { box-shadow: 0 18px 60px rgba(6,182,212,.14); }
@media (max-width: 1160px) { .showcase { grid-template-columns: repeat(3, 1fr); } }
@media (max-width: 920px) { .showcase { grid-template-columns: repeat(2, 1fr); } }
@media (max-width: 560px) { .showcase { grid-template-columns: 1fr; } }

/* === 友情链接 === */
.links { border-top: 1px solid var(--border); border-bottom: 1px solid var(--border); background: #fcfcff; }
.links h2 { text-align: center; margin: 28px 0 8px; }
.link-grid { list-style: none; padding: 0; margin: 18px auto 28px; display: grid; grid-template-columns: repeat(6, 1fr); gap: 12px; width: min(1120px, 92vw); }
.link-grid a { display: block; text-align: center; border: 1px solid var(--border); padding: 10px 14px; border-radius: 999px; background: #fff; transition: box-shadow .2s ease, transform .2s ease; }
.link-grid a:hover { transform: translateY(-1px); box-shadow: 0 12px 30px rgba(168,85,247,.16); }
@media (max-width: 920px) { .link-grid { grid-template-columns: repeat(3, 1fr); } }
@media (max-width: 560px) { .link-grid { grid-template-columns: repeat(2, 1fr); } }

/* === 联系与页脚 === */
.contact { padding: 40px 0; }
.contact h2 { margin: 0 0 8px; }
.contact p { color: var(--muted); }
.site-footer { border-top: 1px solid var(--border); padding: 16px 0 32px; text-align: center; color: var(--muted); }

/* === 可用性优化 === */
::selection { background: rgba(79,70,229,.18); }
:focus-visible { outline: 3px solid rgba(6,182,212,.45); outline-offset: 2px; border-radius: 8px; }