/* ===== u币交易平台 - 顶尖数字资产交易安全高效客户端 ===== */
:root {
  --bg-dark: #0a0e1a;
  --bg-card: #111827;
  --bg-card-2: #0f172a;
  --u-blue: #2563eb;
  --ai-cyan: #06b6d4;
  --quant-purple: #8b5cf6;
  --top-gold: #f59e0b;
  --trade-green: #10b981;
  --text-white: #ffffff;
  --text-muted: #94a3b8;
  --border: rgba(37, 99, 235, 0.18);
  --grad-blue: linear-gradient(135deg, #2563eb 0%, #06b6d4 100%);
  --grad-purple: linear-gradient(135deg, #8b5cf6 0%, #2563eb 100%);
  --grad-gold: linear-gradient(135deg, #f59e0b 0%, #10b981 100%);
}

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

html { scroll-behavior: smooth; }

body {
  font-family: "PingFang SC", "Microsoft YaHei", "Segoe UI", system-ui, sans-serif;
  background: var(--bg-dark);
  color: var(--text-white);
  line-height: 1.7;
  overflow-x: hidden;
}

a { text-decoration: none; color: inherit; }
img { max-width: 100%; display: block; }
ul { list-style: none; }

/* ===== 背景流动光效 ===== */
body::before {
  content: "";
  position: fixed;
  top: 0; left: 0; right: 0; bottom: 0;
  background:
    radial-gradient(circle at 20% 20%, rgba(37, 99, 235, 0.12), transparent 40%),
    radial-gradient(circle at 80% 30%, rgba(6, 182, 212, 0.10), transparent 40%),
    radial-gradient(circle at 50% 80%, rgba(139, 92, 246, 0.10), transparent 45%);
  z-index: -1;
  pointer-events: none;
}

/* ===== 容器 ===== */
.container { width: 100%; max-width: 1200px; margin: 0 auto; padding: 0 24px; }

/* ===== 导航栏 ===== */
header.site-header {
  position: sticky; top: 0; z-index: 100;
  background: rgba(10, 14, 26, 0.85);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
}
.nav-inner { display: flex; align-items: center; justify-content: space-between; height: 68px; }
.brand { font-size: 22px; font-weight: 800; letter-spacing: 0.5px; }
.brand .accent { background: var(--grad-blue); -webkit-background-clip: text; background-clip: text; -webkit-text-fill-color: transparent; }
.nav-links { display: flex; gap: 28px; align-items: center; }
.nav-links a { color: var(--text-muted); font-size: 15px; transition: color .25s; }
.nav-links a:hover, .nav-links a.active { color: var(--text-white); }
.nav-toggle { display: none; background: none; border: none; color: #fff; font-size: 26px; cursor: pointer; }

/* ===== 按钮 ===== */
.btn {
  display: inline-block; padding: 13px 30px; border-radius: 10px;
  font-weight: 700; font-size: 15px; cursor: pointer; border: none;
  transition: transform .2s, box-shadow .25s; text-align: center;
}
.btn-primary { background: var(--grad-blue); color: #fff; box-shadow: 0 8px 24px rgba(37, 99, 235, 0.35); }
.btn-gold { background: var(--grad-gold); color: #0a0e1a; }
.btn-purple { background: var(--grad-purple); color: #fff; }
.btn:hover { transform: translateY(-3px); box-shadow: 0 12px 32px rgba(6, 182, 212, 0.4); }
.btn-pulse { animation: pulse 2s infinite; }
@keyframes pulse {
  0% { box-shadow: 0 0 0 0 rgba(37, 99, 235, 0.5); }
  70% { box-shadow: 0 0 0 16px rgba(37, 99, 235, 0); }
  100% { box-shadow: 0 0 0 0 rgba(37, 99, 235, 0); }
}

/* ===== Hero ===== */
.hero { padding: 90px 0 70px; text-align: center; position: relative; }
.hero h1 { font-size: 46px; font-weight: 900; line-height: 1.25; margin-bottom: 18px; }
.hero h1 .grad { background: var(--grad-blue); -webkit-background-clip: text; background-clip: text; -webkit-text-fill-color: transparent; }
.hero .sub { font-size: 19px; color: var(--text-muted); max-width: 760px; margin: 0 auto 14px; }
.hero .tags { display: flex; flex-wrap: wrap; gap: 10px; justify-content: center; margin: 26px 0 34px; }
.tag { padding: 7px 16px; border-radius: 30px; font-size: 13px; border: 1px solid var(--border); background: var(--bg-card); color: var(--ai-cyan); }
.hero-cta { display: flex; gap: 16px; justify-content: center; flex-wrap: wrap; }
.hero-img { margin: 46px auto 0; max-width: 880px; border-radius: 16px; border: 1px solid var(--border); box-shadow: 0 20px 60px rgba(0,0,0,0.5); }

/* ===== 区块通用 ===== */
section { padding: 70px 0; }
.section-head { text-align: center; margin-bottom: 48px; }
.section-head h2 { font-size: 34px; font-weight: 800; margin-bottom: 12px; }
.section-head p { color: var(--text-muted); font-size: 16px; max-width: 680px; margin: 0 auto; }

/* ===== 仪表盘 ===== */
.dashboard { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.gauge-card { background: var(--bg-card); border: 1px solid var(--border); border-radius: 16px; padding: 28px; text-align: center; }
.gauge-ring { width: 130px; height: 130px; margin: 0 auto 16px; border-radius: 50%; display: flex; align-items: center; justify-content: center; font-size: 30px; font-weight: 800; position: relative; }
.gauge-ring::before { content: ""; position: absolute; inset: 10px; border-radius: 50%; background: var(--bg-dark); }
.gauge-ring span { position: relative; z-index: 1; }
.gauge-card h3 { font-size: 17px; margin-bottom: 6px; }
.gauge-card .desc { color: var(--text-muted); font-size: 13px; }

/* ===== 优势网格 ===== */
.feature-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.feature-card { background: var(--bg-card); border: 1px solid var(--border); border-radius: 16px; padding: 30px; transition: transform .3s, border-color .3s; }
.feature-card:hover { transform: translateY(-6px); border-color: var(--ai-cyan); }
.feature-card .icon { width: 54px; height: 54px; border-radius: 12px; display: flex; align-items: center; justify-content: center; font-size: 26px; margin-bottom: 18px; background: var(--grad-blue); }
.feature-card h3 { font-size: 19px; margin-bottom: 10px; }
.feature-card p { color: var(--text-muted); font-size: 14px; }

/* ===== 数据统计 ===== */
.stats { display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px; }
.stat-box { background: var(--bg-card-2); border: 1px solid var(--border); border-radius: 14px; padding: 26px; text-align: center; }
.stat-box .num { font-size: 36px; font-weight: 900; background: var(--grad-blue); -webkit-background-clip: text; background-clip: text; -webkit-text-fill-color: transparent; }
.stat-box .label { color: var(--text-muted); font-size: 14px; margin-top: 6px; }

/* ===== 行情表 ===== */
.pairs { display: grid; grid-template-columns: repeat(2, 1fr); gap: 16px; }
.pair-row { display: flex; align-items: center; justify-content: space-between; background: var(--bg-card); border: 1px solid var(--border); border-radius: 12px; padding: 16px 20px; }
.pair-row .name { font-weight: 700; }
.pair-row .price { color: var(--trade-green); font-weight: 700; }
.pair-row .chg { font-size: 13px; color: var(--top-gold); }

/* ===== 文章/内容 ===== */
.article-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 24px; }
.article-card { background: var(--bg-card); border: 1px solid var(--border); border-radius: 16px; overflow: hidden; transition: transform .3s; }
.article-card:hover { transform: translateY(-5px); }
.article-card img { width: 100%; height: 180px; object-fit: cover; }
.article-card .body { padding: 22px; }
.article-card h3 { font-size: 18px; margin-bottom: 10px; }
.article-card p { color: var(--text-muted); font-size: 14px; }

/* ===== FAQ ===== */
.faq-item { background: var(--bg-card); border: 1px solid var(--border); border-radius: 12px; margin-bottom: 14px; overflow: hidden; }
.faq-item summary { padding: 18px 22px; cursor: pointer; font-weight: 700; font-size: 16px; list-style: none; display: flex; justify-content: space-between; align-items: center; }
.faq-item summary::-webkit-details-marker { display: none; }
.faq-item summary::after { content: "+"; color: var(--ai-cyan); font-size: 22px; }
.faq-item[open] summary::after { content: "−"; }
.faq-item .answer { padding: 0 22px 20px; color: var(--text-muted); font-size: 14px; }

/* ===== 表单 ===== */
.form-wrap { max-width: 560px; margin: 0 auto; background: var(--bg-card); border: 1px solid var(--border); border-radius: 16px; padding: 36px; }
.form-wrap label { display: block; margin-bottom: 6px; font-size: 14px; color: var(--text-muted); }
.form-wrap input, .form-wrap textarea, .form-wrap select { width: 100%; padding: 12px 14px; background: var(--bg-dark); border: 1px solid var(--border); border-radius: 8px; color: #fff; margin-bottom: 18px; font-size: 14px; }
.form-wrap input:focus, .form-wrap textarea:focus { outline: none; border-color: var(--ai-cyan); }

/* ===== 页脚 ===== */
footer.site-footer { background: var(--bg-card-2); border-top: 1px solid var(--border); padding: 50px 0 30px; margin-top: 40px; }
.footer-grid { display: grid; grid-template-columns: 2fr 1fr 1fr 1fr; gap: 30px; margin-bottom: 30px; }
.footer-grid h4 { font-size: 16px; margin-bottom: 16px; color: var(--ai-cyan); }
.footer-grid a { display: block; color: var(--text-muted); font-size: 14px; margin-bottom: 10px; transition: color .2s; }
.footer-grid a:hover { color: #fff; }
.footer-bottom { text-align: center; color: var(--text-muted); font-size: 13px; border-top: 1px solid var(--border); padding-top: 22px; }

/* ===== 滚动揭示动画 ===== */
.reveal { opacity: 0; transform: translateY(40px); transition: opacity .7s ease, transform .7s ease; }
.reveal.visible { opacity: 1; transform: translateY(0); }

/* ===== 流动性流动效果 ===== */
.flow-line { height: 3px; background: linear-gradient(90deg, transparent, var(--ai-cyan), transparent); background-size: 200% 100%; animation: flow 3s linear infinite; border-radius: 3px; margin: 30px 0; }
@keyframes flow { 0% { background-position: 200% 0; } 100% { background-position: -200% 0; } }

/* ===== 响应式 ===== */
@media (max-width: 900px) {
  .dashboard, .feature-grid, .stats, .article-grid, .pairs { grid-template-columns: 1fr 1fr; }
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .hero h1 { font-size: 34px; }
}
@media (max-width: 600px) {
  .nav-links { display: none; position: absolute; top: 68px; left: 0; right: 0; flex-direction: column; background: var(--bg-dark); padding: 20px; gap: 16px; border-bottom: 1px solid var(--border); }
  .nav-links.open { display: flex; }
  .nav-toggle { display: block; }
  .dashboard, .feature-grid, .stats, .article-grid, .pairs, .footer-grid { grid-template-columns: 1fr; }
  .hero h1 { font-size: 28px; }
  section { padding: 50px 0; }
}