/* ========== 基础 ========== */
:root {
  --bg: #070b16;
  --bg-soft: #0c1224;
  --surface: #111a30;
  --surface-2: #16213c;
  --border: #223055;
  --text: #e8edf7;
  --text-dim: #9aa8c7;
  --accent: #4fd1c5;
  --accent-2: #7f9cf5;
  --accent-3: #b794f4;
  --cn-tag: #f6ad55;
  --intl-tag: #63b3ed;
  --radius: 14px;
  --max-w: 1120px;
}

* { margin: 0; padding: 0; box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  background: var(--bg);
  color: var(--text);
  font-family: "PingFang SC", "Microsoft YaHei", "Noto Sans SC", "Segoe UI", sans-serif;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

a { color: var(--accent); text-decoration: none; }

.wrap { max-width: var(--max-w); margin: 0 auto; padding: 0 24px; }

/* ========== 顶部导航 ========== */
.topbar {
  position: sticky; top: 0; z-index: 50;
  background: rgba(7, 11, 22, 0.82);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
}
.topbar-inner {
  max-width: var(--max-w); margin: 0 auto; padding: 0 24px;
  height: 58px; display: flex; align-items: center; gap: 18px;
}
.brand {
  font-weight: 700; font-size: 16px; letter-spacing: 0.5px;
  background: linear-gradient(90deg, var(--accent), var(--accent-2));
  -webkit-background-clip: text; background-clip: text; color: transparent;
  white-space: nowrap;
}
.nav { display: flex; gap: 4px; overflow-x: auto; scrollbar-width: none; }
.nav::-webkit-scrollbar { display: none; }
.nav a {
  color: var(--text-dim); font-size: 13px; padding: 6px 12px;
  border-radius: 999px; white-space: nowrap; transition: all 0.2s;
}
.nav a:hover { color: var(--text); background: var(--surface-2); }
.nav a.active { color: #06281f; background: var(--accent); font-weight: 600; }

/* ========== Hero ========== */
.hero {
  position: relative; overflow: hidden;
  padding: 88px 0 64px;
  background:
    radial-gradient(ellipse 60% 45% at 20% 0%, rgba(79, 209, 197, 0.12), transparent),
    radial-gradient(ellipse 55% 50% at 85% 15%, rgba(127, 156, 245, 0.14), transparent),
    radial-gradient(ellipse 40% 40% at 55% 90%, rgba(183, 148, 244, 0.08), transparent);
}
.hero .kicker {
  display: inline-block; font-size: 13px; letter-spacing: 2px;
  color: var(--accent); border: 1px solid rgba(79, 209, 197, 0.35);
  padding: 4px 14px; border-radius: 999px; margin-bottom: 22px;
}
.hero h1 {
  font-size: clamp(30px, 5vw, 46px); line-height: 1.25;
  font-weight: 800; margin-bottom: 18px;
}
.hero h1 .grad {
  background: linear-gradient(90deg, var(--accent), var(--accent-2), var(--accent-3));
  -webkit-background-clip: text; background-clip: text; color: transparent;
}
.hero p.lede { max-width: 760px; color: var(--text-dim); font-size: 16px; }
.hero-stats { display: flex; flex-wrap: wrap; gap: 14px; margin-top: 34px; }
.stat-chip {
  background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--radius); padding: 14px 22px; min-width: 130px;
}
.stat-chip b { display: block; font-size: 24px; color: var(--accent); }
.stat-chip span { font-size: 12.5px; color: var(--text-dim); }

/* 过滤开关 */
.filter-bar { display: flex; gap: 10px; margin-top: 30px; flex-wrap: wrap; }
.filter-btn {
  background: var(--surface); color: var(--text-dim);
  border: 1px solid var(--border); border-radius: 999px;
  padding: 7px 18px; font-size: 13.5px; cursor: pointer; transition: all 0.2s;
}
.filter-btn:hover { color: var(--text); border-color: var(--accent-2); }
.filter-btn.on { background: var(--accent-2); border-color: var(--accent-2); color: #0a1030; font-weight: 600; }

/* ========== 平台板块 ========== */
.platform { padding: 64px 0 30px; scroll-margin-top: 70px; }
.platform-head { display: flex; align-items: baseline; gap: 16px; flex-wrap: wrap; margin-bottom: 8px; }
.platform-head .idx {
  font-family: "Consolas", monospace; font-size: 14px; color: var(--accent-2);
  border: 1px solid var(--border); border-radius: 8px; padding: 2px 10px;
}
.platform-head h2 { font-size: clamp(22px, 3.4vw, 30px); font-weight: 750; }
.platform-head .en { color: var(--text-dim); font-size: 14px; }
.platform-desc {
  max-width: 860px; color: var(--text-dim); font-size: 15px;
  border-left: 3px solid var(--accent-2); padding-left: 16px; margin: 14px 0 30px;
}

.group-title {
  display: flex; align-items: center; gap: 10px;
  font-size: 15px; font-weight: 700; margin: 26px 0 16px;
}
.group-title .dot { width: 9px; height: 9px; border-radius: 50%; }
.group-title.cn .dot { background: var(--cn-tag); box-shadow: 0 0 10px var(--cn-tag); }
.group-title.intl .dot { background: var(--intl-tag); box-shadow: 0 0 10px var(--intl-tag); }
.group-title small { color: var(--text-dim); font-weight: 400; }

.cards {
  display: grid; gap: 16px;
  grid-template-columns: repeat(auto-fill, minmax(310px, 1fr));
}

.card {
  background: linear-gradient(160deg, var(--surface), var(--bg-soft));
  border: 1px solid var(--border); border-radius: var(--radius);
  padding: 20px 22px; display: flex; flex-direction: column; gap: 10px;
  transition: transform 0.22s, border-color 0.22s, box-shadow 0.22s;
}
.card:hover {
  transform: translateY(-4px);
  border-color: rgba(79, 209, 197, 0.45);
  box-shadow: 0 12px 30px rgba(0, 0, 0, 0.35);
}
.card-top { display: flex; align-items: center; gap: 10px; flex-wrap: wrap; }
.card-top h3 { font-size: 16.5px; font-weight: 700; }
.tag {
  font-size: 11px; padding: 2px 9px; border-radius: 999px; font-weight: 600;
  border: 1px solid transparent; white-space: nowrap;
}
.tag.cn { color: var(--cn-tag); border-color: rgba(246, 173, 85, 0.4); background: rgba(246, 173, 85, 0.08); }
.tag.intl { color: var(--intl-tag); border-color: rgba(99, 179, 237, 0.4); background: rgba(99, 179, 237, 0.08); }
.card p { font-size: 13.8px; color: var(--text-dim); flex: 1; }
.card .site-link {
  display: inline-flex; align-items: center; gap: 6px;
  font-size: 13px; color: var(--accent); font-weight: 600;
}
.card .site-link::after { content: "→"; transition: transform 0.2s; }
.card .site-link:hover::after { transform: translateX(4px); }
.card .site-link .host { color: var(--text-dim); font-weight: 400; }

/* 平台对比表 */
.compare { padding: 60px 0 20px; }
.compare h2 { font-size: clamp(20px, 3vw, 26px); margin-bottom: 6px; }
.compare .hint { color: var(--text-dim); font-size: 13.5px; margin-bottom: 22px; }
.table-scroll { overflow-x: auto; border: 1px solid var(--border); border-radius: var(--radius); }
table { width: 100%; border-collapse: collapse; min-width: 760px; font-size: 13.5px; }
th, td { padding: 12px 16px; text-align: left; border-bottom: 1px solid var(--border); }
th { background: var(--surface-2); color: var(--text); font-weight: 700; white-space: nowrap; }
td { color: var(--text-dim); }
tr:last-child td { border-bottom: none; }
td:first-child { color: var(--text); font-weight: 600; white-space: nowrap; }
.meter { display: inline-block; height: 8px; border-radius: 4px; background: linear-gradient(90deg, var(--accent), var(--accent-2)); }

/* ========== 页脚 ========== */
footer {
  margin-top: 70px; padding: 34px 0 44px;
  border-top: 1px solid var(--border); color: var(--text-dim); font-size: 13px;
}
footer .wrap { display: flex; justify-content: space-between; gap: 16px; flex-wrap: wrap; }

@media (max-width: 640px) {
  .hero { padding: 60px 0 44px; }
  .cards { grid-template-columns: 1fr; }
  .topbar-inner { height: 52px; }
  .brand { font-size: 14px; }
}