:root {
  --bg: #ffffff;
  --bg-alt: #f6f7f9;
  --ink: #161a23;
  --ink-soft: #4a4f5e;
  --line: #e6e8ee;
  --blue: #4f6bff;
  --purple: #7c5cff;
  --grad: linear-gradient(135deg, #4f6bff 0%, #7c5cff 100%);
  --dark: #11131a;
  --dark-2: #161a23;
  --dark-line: #262b38;
  --gate: #f5a623;
  --ok: #2bb673;
  --radius: 14px;
  --shadow: 0 8px 30px rgba(20, 26, 45, 0.06);
  --maxw: 1080px;
}

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

html { scroll-behavior: smooth; }

body {
  font-family: "Segoe UI", "PingFang SC", "Microsoft YaHei", system-ui, sans-serif;
  color: var(--ink);
  background: var(--bg);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

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

/* ---------- 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  padding: 10px 18px;
  border-radius: 10px;
  font-size: 14px;
  font-weight: 600;
  cursor: pointer;
  border: 1px solid transparent;
  transition: transform .08s ease, box-shadow .15s ease, background .15s ease;
  white-space: nowrap;
}
.btn:active { transform: translateY(1px); }
.btn-lg { padding: 13px 26px; font-size: 15px; }
.btn-primary { background: var(--grad); color: #fff; box-shadow: 0 6px 18px rgba(79,107,255,.28); }
.btn-primary:hover { box-shadow: 0 8px 24px rgba(79,107,255,.36); }
.btn-ghost { background: #fff; color: var(--ink); border-color: var(--line); }
.btn-ghost:hover { border-color: var(--blue); color: var(--blue); }
.btn-human { background: #fff4e3; color: #b9770a; border: 1px solid #f3d39a; }
.btn-human:hover { background: #ffeccc; }

/* ---------- 导航 ---------- */
.nav {
  position: sticky; top: 0; z-index: 50;
  background: rgba(255,255,255,.86);
  backdrop-filter: saturate(160%) blur(10px);
  border-bottom: 1px solid var(--line);
}
.nav-inner {
  max-width: var(--maxw); margin: 0 auto;
  display: flex; align-items: center; gap: 18px;
  padding: 12px 20px;
}
.brand { font-weight: 800; font-size: 17px; display: flex; align-items: center; gap: 8px; }
.brand-dot {
  width: 10px; height: 10px; border-radius: 50%;
  background: var(--grad); box-shadow: 0 0 0 4px rgba(124,92,255,.15);
}
.brand-accent { background: var(--grad); -webkit-background-clip: text; background-clip: text; color: transparent; }
.nav-links { display: flex; gap: 20px; margin-left: auto; font-size: 14px; color: var(--ink-soft); }
.nav-links a:hover { color: var(--blue); }
.nav-cta { margin-left: 6px; }

/* ---------- 声明条 ---------- */
.disclaimer-bar {
  background: var(--dark); color: #c7cbe0;
  text-align: center; font-size: 12.5px; padding: 8px 16px;
}

/* ---------- 首屏 ---------- */
.hero { position: relative; overflow: hidden; padding: 84px 20px 72px; }
.hero-bg {
  position: absolute; inset: 0; z-index: 0;
  background:
    radial-gradient(620px 320px at 78% -8%, rgba(124,92,255,.18), transparent 60%),
    radial-gradient(560px 300px at 8% 12%, rgba(79,107,255,.16), transparent 60%);
}
.hero-inner { position: relative; z-index: 1; max-width: var(--maxw); margin: 0 auto; text-align: center; }
.badge {
  display: inline-block; font-size: 12.5px; font-weight: 600;
  color: var(--blue); background: #eef1ff; border: 1px solid #dfe4ff;
  padding: 6px 14px; border-radius: 999px; margin-bottom: 22px;
}
.hero-title { font-size: 52px; font-weight: 850; letter-spacing: -1px; line-height: 1.1; }
.hero-title .grad { background: var(--grad); -webkit-background-clip: text; background-clip: text; color: transparent; }
.hero-sub { color: var(--ink-soft); font-size: 17px; max-width: 720px; margin: 20px auto 30px; }
.hero-actions { display: flex; gap: 14px; justify-content: center; flex-wrap: wrap; }
.hero-stats {
  display: grid; grid-template-columns: repeat(4, 1fr); gap: 14px;
  max-width: 760px; margin: 52px auto 0;
}
.stat {
  background: #fff; border: 1px solid var(--line); border-radius: var(--radius);
  padding: 18px 10px; box-shadow: var(--shadow);
}
.stat b { display: block; font-size: 26px; font-weight: 800; background: var(--grad); -webkit-background-clip: text; background-clip: text; color: transparent; }
.stat span { font-size: 12.5px; color: var(--ink-soft); }

/* ---------- 通用 section ---------- */
.section { max-width: var(--maxw); margin: 0 auto; padding: 68px 20px; }
.section-alt { max-width: none; background: var(--bg-alt); }
.section-alt > * { max-width: var(--maxw); margin-left: auto; margin-right: auto; }
.section-head { text-align: center; margin-bottom: 40px; }
.section-head h2 { font-size: 32px; font-weight: 800; letter-spacing: -.5px; }
.section-head p { color: var(--ink-soft); margin-top: 10px; }
.sub { font-size: 18px; font-weight: 700; margin: 36px 0 16px; }

/* ---------- 对比 ---------- */
.compare { display: grid; grid-template-columns: 1fr auto 1fr; gap: 18px; align-items: stretch; }
.compare-col { background: #fff; border: 1px solid var(--line); border-radius: var(--radius); padding: 22px 24px; box-shadow: var(--shadow); }
.compare-col h3 { font-size: 16px; margin-bottom: 14px; }
.col-before { color: #8a8f9e; }
.col-after { color: var(--blue); }
.compare-col ul { list-style: none; }
.compare-col li { padding: 9px 0; border-bottom: 1px dashed var(--line); font-size: 14.5px; }
.compare-col li:last-child { border-bottom: none; }
.compare-arrow { display: flex; align-items: center; font-size: 28px; color: var(--purple); font-weight: 800; }

.human-box { margin-top: 24px; background: var(--dark); border-radius: var(--radius); padding: 24px; color: #e7e9f4; }
.human-box h3 { font-size: 16px; color: #fff; margin-bottom: 14px; }
.chips { display: flex; flex-wrap: wrap; gap: 10px; }
.chip { background: rgba(255,255,255,.08); border: 1px solid var(--dark-line); color: #d7dbf0; font-size: 13px; padding: 7px 14px; border-radius: 999px; }
.human-note { margin-top: 14px; font-size: 13.5px; color: #aab0c8; }

/* ---------- 工作流 ---------- */
.flow { display: flex; flex-wrap: wrap; gap: 10px; justify-content: center; }
.flow-node {
  background: #fff; border: 1px solid var(--line); border-radius: 10px;
  padding: 11px 16px; font-size: 13.5px; font-weight: 600;
  box-shadow: var(--shadow); position: relative;
}
.flow-node::after { content: "↓"; position: absolute; right: -12px; top: 50%; transform: translateY(-50%); color: var(--purple); font-weight: 800; }
.flow-node:last-child::after { content: ""; }
.flow-node.gate { background: #fff7ea; border-color: #f3d79a; color: #b9770a; }
.flow-node.done { background: var(--grad); color: #fff; border: none; }

/* ---------- DEMO ---------- */
.demo { background: #fff; border: 1px solid var(--line); border-radius: var(--radius); padding: 24px; box-shadow: var(--shadow); }
.demo-controls { display: flex; gap: 10px; align-items: center; flex-wrap: wrap; }
.demo-progress { margin-left: auto; font-size: 13px; color: var(--ink-soft); font-weight: 600; }
.demo-track { height: 6px; background: var(--line); border-radius: 999px; margin: 18px 0; overflow: hidden; }
.demo-track-fill { height: 100%; width: 0%; background: var(--grad); transition: width .25s ease; }

.step-card { background: var(--dark); border-radius: var(--radius); padding: 22px; color: #e7e9f4; }
.step-top { display: flex; align-items: center; gap: 12px; margin-bottom: 8px; }
.step-no { font-size: 12px; font-weight: 700; color: #aab0c8; letter-spacing: .5px; }
.step-status { font-size: 12px; font-weight: 700; padding: 4px 12px; border-radius: 999px; background: rgba(124,92,255,.18); color: #c6b8ff; }
.step-status.run { background: rgba(79,107,255,.22); color: #b9c6ff; }
.step-status.done { background: rgba(43,182,115,.2); color: #8ff0c0; }
.step-status.wait { background: rgba(245,166,35,.2); color: #ffd28a; }
.step-title { font-size: 22px; font-weight: 800; color: #fff; margin-bottom: 18px; }
.step-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; }
.step-field { background: rgba(255,255,255,.04); border: 1px solid var(--dark-line); border-radius: 10px; padding: 12px 14px; }
.step-field label { display: block; font-size: 11.5px; color: #8b91ab; text-transform: uppercase; letter-spacing: .6px; margin-bottom: 6px; }
.step-field p { font-size: 14px; color: #e7e9f4; }
.step-actions { margin-top: 16px; }
.step-actions .btn-human { width: 100%; padding: 13px; font-size: 15px; }

.step-list { list-style: none; margin-top: 22px; display: grid; grid-template-columns: repeat(2, 1fr); gap: 8px 18px; }
.step-list li { display: flex; align-items: center; gap: 10px; font-size: 13.5px; color: var(--ink-soft); padding: 6px 0; }
.step-list li .dot { width: 9px; height: 9px; border-radius: 50%; background: var(--line); flex: none; }
.step-list li.active { color: var(--ink); font-weight: 700; }
.step-list li.active .dot { background: var(--blue); box-shadow: 0 0 0 4px rgba(79,107,255,.18); }
.step-list li.finished .dot { background: var(--ok); }
.step-list li.gate-item .dot { background: var(--gate); }

/* ---------- 能力卡片 ---------- */
.cards { display: grid; grid-template-columns: repeat(3, 1fr); gap: 12px; }
.card { background: #fff; border: 1px solid var(--line); border-radius: 10px; padding: 14px 16px; font-size: 14px; box-shadow: var(--shadow); }
.card::before { content: "✓ "; color: var(--blue); font-weight: 800; }
.roles { display: grid; grid-template-columns: repeat(3, 1fr); gap: 12px; }
.role { background: var(--dark); border-radius: 10px; padding: 14px 16px; display: flex; flex-direction: column; gap: 4px; }
.role b { color: #fff; font-size: 15px; }
.role span { color: #aab0c8; font-size: 13px; }

/* ---------- 量化 ---------- */
.metric-card { background: var(--dark); border-radius: var(--radius); padding: 32px; color: #e7e9f4; text-align: center; max-width: 720px; margin: 0 auto; }
.metric-big { font-size: 44px; font-weight: 850; background: var(--grad); -webkit-background-clip: text; background-clip: text; color: transparent; }
.metric-card p { color: #c7cbe0; margin-top: 12px; font-size: 14.5px; }
.metric-card code { background: rgba(255,255,255,.08); padding: 2px 7px; border-radius: 6px; font-size: 13px; }
.metric-note { font-size: 13px; color: #9aa0bb !important; }

/* ---------- 案例 ---------- */
.case-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 26px; align-items: start; }
.case-text h3, .case-imgs h3 { font-size: 15px; margin: 16px 0 8px; }
.case-text h3:first-child { margin-top: 0; }
.case-text pre { background: var(--dark); color: #d7dbf0; padding: 14px 16px; border-radius: 10px; font-size: 13px; overflow-x: auto; line-height: 1.7; }
.case-imgs img { width: 100%; border-radius: 12px; border: 1px solid var(--line); display: block; }
.case-grid-img { max-width: 320px; margin: 0 auto; }
.case-grid-img p, .case-note { font-size: 12.5px; color: var(--ink-soft); text-align: center; margin-top: 8px; }
.case-out { display: grid; grid-template-columns: repeat(3, 1fr); gap: 8px; margin-top: 14px; }

/* ---------- 边界 ---------- */
.bound-list { list-style: none; display: grid; grid-template-columns: repeat(3, 1fr); gap: 10px; }
.bound-list li { background: #fff; border: 1px solid var(--line); border-left: 3px solid var(--purple); border-radius: 8px; padding: 11px 14px; font-size: 13.5px; box-shadow: var(--shadow); }
.boundary-quote { text-align: center; margin-top: 26px; font-size: 15px; color: var(--ink-soft); font-style: italic; }

/* ---------- 迭代 ---------- */
.iter { display: grid; gap: 12px; max-width: 760px; margin: 0 auto; }
.iter-item { display: flex; align-items: center; gap: 14px; background: #fff; border: 1px solid var(--line); border-radius: 10px; padding: 14px 18px; box-shadow: var(--shadow); flex-wrap: wrap; }
.iter-prob { font-size: 14px; color: var(--ink-soft); flex: 1 1 240px; }
.iter-arrow { color: var(--purple); font-weight: 800; font-size: 18px; }
.iter-fix { font-size: 14px; font-weight: 700; color: var(--blue); flex: 1 1 240px; }

/* ---------- 路线 ---------- */
.roadmap { display: flex; flex-wrap: wrap; gap: 10px; justify-content: center; }

/* ---------- 页脚 ---------- */
.footer { background: var(--dark); color: #9aa0bb; text-align: center; padding: 30px 20px; }
.footer-disclaimer { font-size: 12.5px; max-width: 760px; margin: 0 auto 8px; line-height: 1.7; }
.footer-copy { font-size: 12px; color: #6f7595; }

/* ---------- 响应式 ---------- */
@media (max-width: 820px) {
  .hero-title { font-size: 38px; }
  .hero-stats { grid-template-columns: repeat(2, 1fr); }
  .compare { grid-template-columns: 1fr; }
  .compare-arrow { transform: rotate(90deg); justify-content: center; }
  .cards, .roles, .bound-list { grid-template-columns: 1fr 1fr; }
  .step-grid { grid-template-columns: 1fr; }
  .step-list { grid-template-columns: 1fr; }
  .case-grid { grid-template-columns: 1fr; }
  .nav-links { display: none; }
  .section-head h2 { font-size: 26px; }
}
@media (max-width: 520px) {
  .hero { padding: 56px 16px 48px; }
  .hero-title { font-size: 30px; }
  .cards, .roles, .bound-list { grid-template-columns: 1fr; }
  .hero-stats { grid-template-columns: 1fr 1fr; }
  .nav-cta { padding: 8px 14px; }
  .btn-lg { padding: 11px 20px; font-size: 14px; }
}