:root {
  --bg: #0b0f17;
  --bg-2: #111722;
  --surface: #161b22;
  --surface-2: #1c232e;
  --border: #232a35;
  --text: #e6edf3;
  --muted: #8b949e;
  --accent: #22d3ee;
  --accent-2: #a78bfa;
  --grad: linear-gradient(120deg, #22d3ee, #a78bfa);
  --radius: 16px;
  --shadow: 0 10px 30px rgba(0, 0, 0, .35);
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: "PingFang SC", "Microsoft YaHei", system-ui, -apple-system, Segoe UI, Roboto, Helvetica, Arial, sans-serif;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

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

.container { width: min(1080px, 92vw); margin: 0 auto; }

/* ---------- 导航 ---------- */
.nav {
  position: sticky;
  top: 0;
  z-index: 50;
  backdrop-filter: blur(10px);
  background: rgba(11, 15, 23, .72);
  border-bottom: 1px solid var(--border);
}
.nav-inner { display: flex; align-items: center; justify-content: space-between; height: 64px; }
.brand { display: flex; align-items: center; gap: 10px; font-weight: 700; font-size: 17px; }
.brand-mark {
  display: grid; place-items: center;
  width: 30px; height: 30px; border-radius: 9px;
  background: var(--grad); color: #08111b; font-size: 18px; font-weight: 800;
}
.nav-links { display: flex; gap: 28px; }
.nav-links a { color: var(--muted); font-size: 15px; transition: color .2s; }
.nav-links a:hover { color: var(--text); }
.nav-toggle { display: none; background: none; border: 0; color: var(--text); font-size: 22px; cursor: pointer; }

/* ---------- 首屏 ---------- */
.hero { position: relative; overflow: hidden; padding: 110px 0 96px; }
.hero-grid {
  position: absolute; inset: 0; z-index: 0; opacity: .5;
  background-image:
    linear-gradient(rgba(34, 211, 238, .06) 1px, transparent 1px),
    linear-gradient(90deg, rgba(167, 139, 250, .06) 1px, transparent 1px);
  background-size: 44px 44px;
  mask-image: radial-gradient(circle at 50% 30%, #000, transparent 75%);
}
.hero-inner { position: relative; z-index: 1; text-align: center; }
.hero-badge {
  display: inline-block; padding: 6px 14px; border: 1px solid var(--border);
  border-radius: 999px; color: var(--muted); font-size: 13px; margin-bottom: 22px;
  background: var(--surface);
}
.hero-title { font-size: clamp(38px, 7vw, 68px); margin: 0 0 18px; line-height: 1.1; letter-spacing: -1px; }
.grad { background: var(--grad); -webkit-background-clip: text; background-clip: text; color: transparent; }
.hero-sub { max-width: 620px; margin: 0 auto 32px; color: var(--muted); font-size: 17px; }
.hero-actions { display: flex; gap: 14px; justify-content: center; flex-wrap: wrap; }

.btn {
  display: inline-flex; align-items: center; justify-content: center;
  padding: 12px 26px; border-radius: 12px; font-size: 15px; font-weight: 600;
  border: 1px solid transparent; transition: transform .15s, box-shadow .2s, background .2s; cursor: pointer;
}
.btn-primary { background: var(--grad); color: #08111b; }
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 8px 24px rgba(34, 211, 238, .3); }
.btn-ghost { border-color: var(--border); color: var(--text); background: var(--surface); }
.btn-ghost:hover { border-color: var(--accent); }

/* ---------- 通用 section ---------- */
.section { padding: 88px 0; }
.section-alt { background: var(--bg-2); border-top: 1px solid var(--border); border-bottom: 1px solid var(--border); }
.section-head { text-align: center; margin-bottom: 48px; }
.section-head.left { text-align: left; margin-bottom: 28px; }
.section-head h2 { font-size: clamp(26px, 4vw, 38px); margin: 0 0 10px; }
.section-head p { color: var(--muted); margin: 0; }

/* ---------- 产品卡片 ---------- */
.cards { display: grid; grid-template-columns: repeat(2, 1fr); gap: 22px; }
.card {
  background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius);
  padding: 28px 24px; box-shadow: var(--shadow); transition: transform .2s, border-color .2s;
}
.card:hover { transform: translateY(-6px); border-color: var(--accent); }
.card-icon {
  width: 52px; height: 52px; border-radius: 14px; display: grid; place-items: center;
  font-size: 26px; background: var(--surface-2); border: 1px solid var(--border); margin-bottom: 16px;
}
.card h3 { margin: 0 0 10px; font-size: 19px; }
.card p { color: var(--muted); margin: 0 0 16px; font-size: 15px; }
.card-list { list-style: none; padding: 0; margin: 0 0 18px; }
.card-list li { position: relative; padding-left: 20px; color: #c9d1d9; font-size: 14px; margin: 6px 0; }
.card-list li::before { content: "▹"; position: absolute; left: 0; color: var(--accent); }
.card-link { color: var(--accent); font-size: 14px; font-weight: 600; }
.card-actions { display: flex; align-items: center; gap: 14px; flex-wrap: wrap; }
.card-download {
  display: inline-flex; align-items: center; gap: 4px;
  padding: 7px 16px; border-radius: 10px; font-size: 14px; font-weight: 600;
  color: #08111b; background: var(--grad); border: 1px solid transparent;
  transition: transform .15s, box-shadow .2s;
}
.card-download:hover { transform: translateY(-2px); box-shadow: 0 8px 22px rgba(34, 211, 238, .3); }

/* ---------- 优势 ---------- */
.features { display: grid; grid-template-columns: repeat(4, 1fr); gap: 18px; }
.feature {
  background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius);
  padding: 24px 20px; transition: border-color .2s;
}
.feature:hover { border-color: var(--accent-2); }
.feature-num { font-size: 22px; font-weight: 800; background: var(--grad); -webkit-background-clip: text; background-clip: text; color: transparent; margin-bottom: 10px; }
.feature h3 { margin: 0 0 8px; font-size: 17px; }
.feature p { color: var(--muted); margin: 0; font-size: 14px; }

/* ---------- PDF 量产工具 / CAD 插件详解 ---------- */
.pdf-detail,
.cad-detail {
  margin-top: 44px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 36px 32px;
  box-shadow: var(--shadow);
  scroll-margin-top: 80px;
}
.cad-shots {
  display: grid; grid-template-columns: 1.35fr 1fr; gap: 24px; align-items: start;
  margin-bottom: 30px;
}
.cad-info-grid {
  display: grid; grid-template-columns: repeat(3, 1fr); gap: 28px;
  padding-top: 26px; border-top: 1px solid var(--border);
}
.pdf-head h3 { margin: 0 0 8px; font-size: 24px; }
.pdf-head p { color: var(--muted); margin: 0 0 28px; font-size: 15px; }
.pdf-grid { display: grid; grid-template-columns: 1.15fr .85fr; gap: 32px; align-items: start; }
.pdf-shot { margin: 0; }
.pdf-shot img {
  width: 100%; display: block; border-radius: 12px;
  border: 1px solid var(--border); background: #fff;
}
.pdf-shot figcaption { color: var(--muted); font-size: 13px; margin-top: 10px; text-align: center; }
.pdf-info h4 {
  margin: 0 0 12px; font-size: 17px; padding-left: 12px;
  border-left: 3px solid var(--accent);
}
.pdf-info h4 + .pdf-list { margin-bottom: 26px; }
.pdf-list { list-style: none; padding: 0; margin: 0; }
.pdf-list li {
  position: relative; padding-left: 20px; margin: 8px 0;
  color: #c9d1d9; font-size: 14px;
}
.pdf-list li::before { content: "▹"; position: absolute; left: 0; color: var(--accent); }

/* ---------- 联系 ---------- */
.contact-inner { display: grid; grid-template-columns: 1.2fr .8fr; gap: 40px; align-items: center; }
.contact-rows { margin-top: 8px; }
.contact-row { display: flex; gap: 16px; padding: 14px 0; border-bottom: 1px solid var(--border); }
.contact-key { color: var(--accent); font-weight: 700; min-width: 64px; }
.contact-val { color: #c9d1d9; }
.qr-wrap { display: flex; justify-content: center; }
.qr-card {
  background: #fff; border-radius: 18px; padding: 18px; box-shadow: 0 14px 40px rgba(0, 0, 0, .45);
  text-align: center;
}
.qr-card img { width: 220px; height: 220px; display: block; border-radius: 8px; }
.qr-tip { margin: 10px 0 0; color: #444; font-size: 14px; font-weight: 600; }

/* ---------- 页脚 ---------- */
.footer { border-top: 1px solid var(--border); padding: 26px 0; }
.footer-inner { display: flex; justify-content: space-between; color: var(--muted); font-size: 14px; flex-wrap: wrap; gap: 8px; }

/* ---------- 响应式 ---------- */
@media (max-width: 860px) {
  .cards { grid-template-columns: 1fr; }
  .features { grid-template-columns: repeat(2, 1fr); }
  .contact-inner { grid-template-columns: 1fr; }
  .pdf-detail, .cad-detail { padding: 24px 18px; }
  .pdf-grid { grid-template-columns: 1fr; }
  .cad-shots { grid-template-columns: 1fr; }
  .cad-info-grid { grid-template-columns: 1fr; }
  .nav-links {
    position: absolute; top: 64px; left: 0; right: 0; flex-direction: column; gap: 0;
    background: var(--bg-2); border-bottom: 1px solid var(--border);
    max-height: 0; overflow: hidden; transition: max-height .25s;
  }
  .nav-links.open { max-height: 240px; }
  .nav-links a { padding: 14px 6vw; border-top: 1px solid var(--border); }
  .nav-toggle { display: block; }
}
@media (max-width: 480px) {
  .features { grid-template-columns: 1fr; }
}