:root {
  --bg: #0b1020;
  --bg-alt: #0f1730;
  --surface: #151d38;
  --surface-2: #1c274a;
  --text: #e8edf7;
  --text-dim: #9aa6c4;
  --primary: #4f8cff;
  --primary-2: #7c5cff;
  --accent: #21d4a8;
  --border: rgba(255, 255, 255, 0.08);
  --radius: 16px;
  --maxw: 1120px;
}

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

html { scroll-behavior: smooth; }

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

a { color: inherit; text-decoration: none; }

code {
  font-family: "JetBrains Mono", Consolas, monospace;
  background: rgba(79, 140, 255, 0.12);
  color: #bcd4ff;
  padding: 1px 7px;
  border-radius: 6px;
  font-size: 0.9em;
}

/* 按钮 */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 11px 22px;
  border-radius: 10px;
  font-weight: 600;
  font-size: 15px;
  cursor: pointer;
  transition: transform .15s ease, box-shadow .2s ease, background .2s ease;
  border: 1px solid transparent;
}
.btn:hover { transform: translateY(-2px); }
.btn-primary {
  background: linear-gradient(135deg, var(--primary), var(--primary-2));
  color: #fff;
  box-shadow: 0 8px 24px rgba(79, 140, 255, 0.35);
}
.btn-primary:hover { box-shadow: 0 12px 32px rgba(79, 140, 255, 0.5); }
.btn-ghost {
  background: rgba(255, 255, 255, 0.04);
  border-color: var(--border);
  color: var(--text);
}
.btn-ghost:hover { background: rgba(255, 255, 255, 0.1); }
.btn-lg { padding: 14px 30px; font-size: 16px; border-radius: 12px; }

/* 导航 */
.nav {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(11, 16, 32, 0.8);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
}
.nav-inner {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 14px 24px;
  display: flex;
  align-items: center;
  gap: 20px;
}
.brand { display: flex; align-items: center; gap: 10px; font-weight: 700; font-size: 17px; }
.brand-logo-img {
  width: 32px; height: 32px;
  border-radius: 8px;
  object-fit: contain;
  display: block;
}
.footer-brand .brand-logo-img { width: 30px; height: 30px; }
.nav-links { display: flex; gap: 26px; margin-left: 20px; flex: 1; }
.nav-links a { color: var(--text-dim); font-size: 15px; transition: color .2s; }
.nav-links a:hover { color: var(--text); }
.nav-cta { padding: 9px 18px; font-size: 14px; }
.nav-toggle { display: none; background: none; border: none; color: var(--text); font-size: 24px; cursor: pointer; }

/* Hero */
.hero { position: relative; overflow: hidden; padding: 90px 24px 70px; }
.hero-bg {
  position: absolute; inset: 0;
  background:
    radial-gradient(700px 380px at 18% 12%, rgba(79, 140, 255, 0.35), transparent 60%),
    radial-gradient(600px 360px at 85% 20%, rgba(124, 92, 255, 0.30), transparent 60%),
    radial-gradient(500px 300px at 60% 90%, rgba(33, 212, 168, 0.18), transparent 60%);
  filter: blur(2px);
}
.hero-inner { position: relative; max-width: var(--maxw); margin: 0 auto; text-align: center; }
.badge {
  display: inline-block;
  padding: 6px 16px;
  border-radius: 999px;
  background: rgba(79, 140, 255, 0.14);
  border: 1px solid rgba(79, 140, 255, 0.3);
  color: #bcd4ff;
  font-size: 13px;
  margin-bottom: 22px;
}
.hero h1 { font-size: 52px; line-height: 1.15; font-weight: 800; letter-spacing: -1px; }
.grad {
  background: linear-gradient(120deg, var(--primary), var(--accent));
  -webkit-background-clip: text; background-clip: text; color: transparent;
}
.hero-sub { max-width: 720px; margin: 22px auto 0; color: var(--text-dim); font-size: 18px; }
.hero-actions { margin-top: 34px; display: flex; gap: 16px; justify-content: center; flex-wrap: wrap; }
.hero-stats {
  margin-top: 54px;
  display: grid; grid-template-columns: repeat(4, 1fr); gap: 18px;
  max-width: 760px; margin-left: auto; margin-right: auto;
}
.stat {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 18px 10px;
}
.stat b { display: block; font-size: 30px; font-weight: 800; color: var(--primary); }
.stat span { font-size: 13px; color: var(--text-dim); }

/* 区块 */
.section { padding: 80px 24px; }
.section-alt { background: var(--bg-alt); }
.section-head { max-width: var(--maxw); margin: 0 auto 48px; text-align: center; }
.section-head h2 { font-size: 36px; font-weight: 800; letter-spacing: -0.5px; }
.section-head p { color: var(--text-dim); margin-top: 12px; font-size: 17px; }

/* 功能卡片 */
.cards {
  max-width: var(--maxw); margin: 0 auto;
  display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px;
}
.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 26px 22px;
  transition: transform .2s ease, border-color .2s ease, background .2s ease;
}
.card:hover { transform: translateY(-4px); border-color: rgba(79, 140, 255, 0.4); background: var(--surface-2); }
.card-icon { font-size: 30px; margin-bottom: 14px; }
.card h3 { font-size: 18px; margin-bottom: 10px; }
.card p { color: var(--text-dim); font-size: 14.5px; }

/* 下载 */
.download-box {
  max-width: var(--maxw); margin: 0 auto 22px;
  display: grid; grid-template-columns: 1.6fr 1fr; gap: 24px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 20px;
  padding: 36px;
}

.download-box-classic {
  background: linear-gradient(180deg, #1a2342 0%, #151d38 100%);
  border-style: dashed;
}
.download-main .dl-title { font-size: 26px; font-weight: 800; }
.download-main .dl-meta { color: var(--text-dim); margin: 8px 0 22px; }
.dl-actions { display: flex; gap: 14px; flex-wrap: wrap; }
.download-side {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 22px;
}
.download-side h4 { margin-bottom: 12px; font-size: 16px; }
.download-side ul { list-style: none; }
.download-side li { padding: 6px 0 6px 22px; position: relative; color: var(--text-dim); font-size: 14.5px; }
.download-side li::before { content: "✓"; position: absolute; left: 0; color: var(--accent); font-weight: 700; }
.dl-tip { max-width: var(--maxw); margin: 22px auto 0; text-align: center; color: var(--text-dim); }

/* 教程 */
.steps { max-width: 880px; margin: 0 auto; display: flex; flex-direction: column; gap: 22px; }
.step { display: flex; gap: 20px; background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 26px; }
.step-num {
  flex: 0 0 46px; height: 46px;
  display: grid; place-items: center;
  border-radius: 12px;
  background: linear-gradient(135deg, var(--primary), var(--primary-2));
  color: #fff; font-weight: 800; font-size: 20px;
}
.step-body h3 { font-size: 19px; margin-bottom: 8px; }
.step-body p { color: var(--text-dim); font-size: 15px; }
.step-body p + .code, .step-body h3 + p { margin-top: 12px; }
.code { position: relative; background: #0a0f1f; border: 1px solid var(--border); border-radius: 12px; padding: 16px 18px; margin-top: 14px; }
.code pre { font-family: "JetBrains Mono", Consolas, monospace; font-size: 13.5px; color: #cfe0ff; white-space: pre-wrap; }
.copy {
  position: absolute; top: 10px; right: 10px;
  background: rgba(255,255,255,0.08); border: 1px solid var(--border);
  color: var(--text-dim); font-size: 12px; padding: 4px 10px; border-radius: 7px; cursor: pointer;
  transition: background .2s, color .2s;
}
.copy:hover { background: rgba(79,140,255,0.25); color: #fff; }
.note {
  max-width: 880px; margin: 30px auto 0;
  background: rgba(33, 212, 168, 0.08);
  border: 1px solid rgba(33, 212, 168, 0.25);
  border-radius: 12px; padding: 18px 22px; color: var(--text-dim); font-size: 14.5px;
}
.note b { color: var(--accent); }

/* 架构 */
.arch {
  max-width: var(--maxw); margin: 0 auto;
  display: flex; align-items: stretch; gap: 10px; justify-content: center; flex-wrap: wrap;
}
.arch-node {
  flex: 1 1 220px; min-width: 200px;
  background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--radius); padding: 24px 20px;
}
.arch-node h4 { font-size: 17px; margin-bottom: 10px; color: var(--primary); }
.arch-node p { color: var(--text-dim); font-size: 14px; }
.arch-arrow { display: grid; place-items: center; color: var(--primary); font-size: 26px; font-weight: 800; }
.arch-extra {
  max-width: var(--maxw); margin: 24px auto 0;
  display: flex; gap: 12px; justify-content: center; flex-wrap: wrap;
}
.arch-extra span {
  background: var(--surface-2); border: 1px solid var(--border);
  padding: 8px 16px; border-radius: 999px; font-size: 13.5px; color: var(--text-dim);
}

/* FAQ */
.faq { max-width: 820px; margin: 0 auto; display: flex; flex-direction: column; gap: 12px; }
.faq details {
  background: var(--surface); border: 1px solid var(--border);
  border-radius: 12px; padding: 4px 20px;
}
.faq summary {
  cursor: pointer; padding: 16px 0; font-weight: 600; font-size: 16px;
  list-style: none; position: relative; padding-right: 28px;
}
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after { content: "+"; position: absolute; right: 0; top: 14px; font-size: 22px; color: var(--primary); transition: transform .2s; }
.faq details[open] summary::after { transform: rotate(45deg); }
.faq details p { color: var(--text-dim); font-size: 14.5px; padding: 0 0 18px; }

/* 页脚 */
.footer { background: var(--bg-alt); border-top: 1px solid var(--border); padding: 50px 24px; text-align: center; }
.footer-inner { max-width: var(--maxw); margin: 0 auto; }
.footer-brand { display: inline-flex; align-items: center; gap: 10px; font-weight: 700; font-size: 18px; margin-bottom: 12px; }
.footer p { color: var(--text-dim); font-size: 14px; }
.copyright { margin-top: 14px; font-size: 12.5px; opacity: 0.7; }

/* 响应式 */
@media (max-width: 980px) {
  .cards { grid-template-columns: repeat(2, 1fr); }
  .hero-stats { grid-template-columns: repeat(2, 1fr); }
  .download-box { grid-template-columns: 1fr; }
}
@media (max-width: 720px) {
  .nav-links { display: none; position: absolute; top: 60px; left: 0; right: 0; flex-direction: column; background: var(--bg); padding: 16px 24px; border-bottom: 1px solid var(--border); }
  .nav-links.open { display: flex; }
  .nav-toggle { display: block; margin-left: auto; }
  .nav-cta { display: none; }
  .hero h1 { font-size: 36px; }
  .section { padding: 56px 18px; }
  .section-head h2 { font-size: 28px; }
  .cards { grid-template-columns: 1fr; }
  .arch-arrow { transform: rotate(90deg); }
}