/* ============================================================
   塔吊安全头盔 · 项目站设计系统
   视觉语言与上位机 GUI 同源:
   深空蓝黑 #0B1424 / 安全橙 #FF8A3D / 工程黄 #FFC53D
   信号绿 #2FD27D / 警报红 #FF4D5E
   ============================================================ */

:root {
  --ink: #0b1424;          /* 深空蓝黑 */
  --ink-2: #101c31;
  --ink-3: #16233c;
  --paper: #f4f6fa;        /* 页面浅底 */
  --card: #ffffff;
  --text: #17253c;
  --sub: #5a6b84;
  --faint: #8a99b0;
  --line: #dce3ee;
  --orange: #ff8a3d;       /* 安全橙 */
  --orange-deep: #e86f22;
  --yellow: #ffc53d;       /* 工程黄 */
  --green: #2fd27d;        /* 信号绿 */
  --green-bg: #e5f7ee;
  --red: #ff4d5e;          /* 警报红 */
  --red-bg: #fdecee;
  --violet: #7967d8;
  --violet-bg: #efedfb;
  --brown: #a06a3f;
  --brown-bg: #f7efe6;
  --amber: #c98a12;
  --amber-bg: #fdf3dd;
  --navy-text: #eaf1fb;
  --navy-sub: #9fb2cc;
  --radius: 22px;
  --radius-s: 14px;
  --shadow: 0 10px 30px rgba(11, 20, 36, .08);
  --font: "Manrope", "Noto Sans SC", "Microsoft YaHei UI", "PingFang SC", sans-serif;
}

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

html { scroll-behavior: smooth; }

body {
  font-family: var(--font);
  background: var(--paper);
  color: var(--text);
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
}

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

.wrap { max-width: 1120px; margin: 0 auto; padding: 0 28px; }

/* ============ 顶部导航 ============ */
.site-header {
  position: sticky; top: 0; z-index: 50;
  background: rgba(244, 246, 250, .92);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--line);
}
.header-in {
  display: flex; align-items: center; gap: 22px;
  padding: 14px 0;
}
.brand { display: flex; align-items: center; gap: 12px; margin-right: auto; }
.brand-mark {
  width: 44px; height: 44px; border-radius: 50%;
  background: var(--orange); color: #fff;
  display: flex; align-items: center; justify-content: center;
  font-size: 21px; font-weight: 800;
  box-shadow: 0 4px 12px rgba(255, 138, 61, .35);
}
.brand-name { font-size: 17px; font-weight: 800; letter-spacing: .5px; }
.brand-sub {
  font-size: 10.5px; letter-spacing: 2.5px; color: var(--faint);
  font-weight: 700; text-transform: uppercase;
}
.nav { display: flex; gap: 6px; }
.nav a {
  padding: 8px 15px; border-radius: 999px; font-size: 14px;
  color: var(--sub); font-weight: 600; transition: .18s;
}
.nav a:hover { color: var(--ink); background: #e9eef6; }
.nav a.active { color: #fff; background: var(--ink); }
.nav-cta {
  padding: 9px 18px; border-radius: 999px; font-size: 14px; font-weight: 700;
  color: #fff; background: var(--orange);
  box-shadow: 0 4px 14px rgba(255, 138, 61, .4);
  transition: .18s;
}
.nav-cta:hover { background: var(--orange-deep); transform: translateY(-1px); }
.menu-btn { display: none; border: none; background: none; cursor: pointer;
  font-size: 22px; color: var(--ink); padding: 6px; }

/* ============ 区块骨架 ============ */
.section { padding: 72px 0; }
.section.dark { background: var(--ink); color: var(--navy-text); }
.section.tight { padding: 52px 0; }

.kicker {
  display: flex; align-items: center; gap: 10px;
  font-size: 12px; font-weight: 800; letter-spacing: 2.5px;
  color: var(--orange); text-transform: uppercase; margin-bottom: 14px;
}
.kicker::before { content: ""; width: 26px; height: 3px; border-radius: 2px;
  background: var(--orange); }
.dark .kicker { color: var(--yellow); }
.dark .kicker::before { background: var(--yellow); }

h1 { font-size: clamp(34px, 5.2vw, 56px); line-height: 1.22; font-weight: 800;
  letter-spacing: .5px; }
h1 em, h2 em { font-style: normal; color: var(--orange); }
.dark h1 em, .dark h2 em { color: var(--yellow); }
h2 { font-size: clamp(26px, 3.6vw, 36px); line-height: 1.3; font-weight: 800;
  margin-bottom: 18px; }
h3 { font-size: 18px; font-weight: 800; margin-bottom: 8px; }
.lead { font-size: 17px; color: var(--sub); max-width: 720px; }
.dark .lead { color: var(--navy-sub); }

/* ============ 证据标签 ============ */
.tag {
  display: inline-flex; align-items: center; gap: 6px;
  font-size: 12px; font-weight: 700; line-height: 1;
  padding: 5px 11px; border-radius: 999px; white-space: nowrap;
}
.tag::before { content: ""; width: 7px; height: 7px; border-radius: 50%;
  background: currentColor; }
.t-impl     { color: #15803d; background: var(--green-bg); }
.t-verified { color: #0e7a4e; background: #e0f4e9; }
.t-pending  { color: var(--amber); background: var(--amber-bg); }
.t-lit      { color: var(--violet); background: var(--violet-bg); }
.t-infer    { color: var(--brown); background: var(--brown-bg); }
.t-concept  { color: #64748b; background: #eef2f7; }

/* ============ Hero ============ */
.hero { padding: 84px 0 64px; position: relative; overflow: hidden; }
.hero::before {
  content: ""; position: absolute; inset: 0;
  background:
    radial-gradient(600px 300px at 85% 10%, rgba(255, 197, 61, .16), transparent 65%),
    radial-gradient(500px 320px at 10% 90%, rgba(255, 138, 61, .12), transparent 65%);
  pointer-events: none;
}
.hero-grid { display: grid; grid-template-columns: 1.25fr .9fr; gap: 48px;
  align-items: center; position: relative; }
.hero-badges { display: flex; flex-wrap: wrap; gap: 8px; margin: 20px 0 26px; }
.hero-cta { display: flex; gap: 14px; flex-wrap: wrap; margin-top: 30px; }
.btn {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 13px 26px; border-radius: 999px;
  font-size: 15px; font-weight: 800; transition: .18s;
}
.btn-primary { background: var(--orange); color: #fff;
  box-shadow: 0 6px 20px rgba(255, 138, 61, .4); }
.btn-primary:hover { background: var(--orange-deep); transform: translateY(-2px); }
.btn-ghost { border: 2px solid var(--ink); color: var(--ink); }
.btn-ghost:hover { background: var(--ink); color: #fff; }

/* 警示条纹装饰 */
.hazard {
  height: 10px; border-radius: 6px;
  background: repeating-linear-gradient(-45deg,
    var(--yellow) 0 14px, var(--ink) 14px 28px);
}
.hero-visual { position: relative; }
.hero-shot {
  border-radius: var(--radius); box-shadow:
    0 24px 60px rgba(11, 20, 36, .25);
  border: 1px solid var(--line);
}
.hero-chip {
  position: absolute; left: -14px; bottom: 26px;
  background: #fff; border-radius: 14px; padding: 10px 16px;
  box-shadow: var(--shadow); font-size: 13px; font-weight: 700;
  display: flex; align-items: center; gap: 9px;
}
.hero-chip .dot { width: 10px; height: 10px; border-radius: 50%; background: var(--red); }

/* ============ 指标行 ============ */
.metrics {
  display: grid; grid-template-columns: repeat(4, 1fr); gap: 16px;
}
.metric {
  background: var(--card); border: 1px solid var(--line);
  border-radius: var(--radius-s); padding: 20px 22px;
}
.metric b { display: block; font-size: 30px; font-weight: 800;
  color: var(--ink); letter-spacing: .5px; }
.metric b small { font-size: 15px; color: var(--orange); font-weight: 800; }
.metric span { font-size: 13px; color: var(--sub); font-weight: 600; }

/* ============ 卡片网格 ============ */
.cards { display: grid; grid-template-columns: repeat(2, 1fr); gap: 18px; }
.card {
  background: var(--card); border: 1px solid var(--line);
  border-radius: var(--radius); padding: 26px;
  transition: .2s;
}
.card:hover { transform: translateY(-3px); box-shadow: var(--shadow);
  border-color: #c9d6e8; }
.card .num { font-size: 13px; font-weight: 800; color: var(--orange);
  letter-spacing: 2px; margin-bottom: 8px; }
.card p { font-size: 14.5px; color: var(--sub); margin-top: 6px; }
.card .tag { margin-top: 14px; }

/* ============ 流程 / 链路 ============ */
.flow { display: grid; grid-template-columns: repeat(4, 1fr); gap: 14px; }
.flow-step {
  background: var(--ink-2); border: 1px solid #22314f;
  border-radius: var(--radius-s); padding: 20px; position: relative;
}
.flow-step .step-tag { font-size: 11px; font-weight: 800; letter-spacing: 2px;
  color: var(--yellow); }
.flow-step h4 { color: var(--navy-text); font-size: 16px; margin: 8px 0 6px; }
.flow-step p { color: var(--navy-sub); font-size: 13px; line-height: 1.65; }
.flow-step::after {
  content: "→"; position: absolute; right: -14px; top: 50%;
  transform: translateY(-50%); color: var(--yellow); font-weight: 800;
  z-index: 2;
}
.flow-step:last-child::after { content: none; }

/* ============ 表格 ============ */
.tbl { width: 100%; border-collapse: collapse; font-size: 14px;
  background: var(--card); border-radius: var(--radius-s); overflow: hidden;
  box-shadow: var(--shadow); }
.tbl th {
  background: var(--ink); color: var(--navy-text); text-align: left;
  padding: 12px 16px; font-size: 13px; letter-spacing: 1px;
}
.tbl td { padding: 12px 16px; border-top: 1px solid var(--line);
  color: var(--text); vertical-align: top; }
.tbl tr:hover td { background: #f8fafd; }
.tbl code {
  background: #eef2f8; padding: 2px 8px; border-radius: 6px;
  font-family: "Cascadia Code", Consolas, monospace; font-size: 12.5px;
  color: var(--orange-deep); font-weight: 700;
}
.dark .tbl { background: var(--ink-2); }
.dark .tbl th { background: #1a2a47; }
.dark .tbl td { color: var(--navy-text); border-top-color: #22314f; }
.dark .tbl code { background: #1d2c48; color: var(--yellow); }

/* ============ 提示框 ============ */
.note {
  border-left: 4px solid var(--yellow); background: #fff9ea;
  padding: 14px 18px; border-radius: 0 var(--radius-s) var(--radius-s) 0;
  font-size: 14px; color: #6b5410;
}
.note.blue { border-color: #5eb8ff; background: #ecf6ff; color: #14507e; }

/* ============ 截图 ============ */
.shots { display: grid; grid-template-columns: 1fr 1fr; gap: 18px; }
.shot { background: var(--card); border: 1px solid var(--line);
  border-radius: var(--radius); padding: 12px; }
.shot img { border-radius: 14px; }
.shot figcaption { font-size: 13px; color: var(--sub); padding: 10px 6px 2px;
  font-weight: 600; }

/* ============ 页脚 ============ */
.site-footer { background: var(--ink); color: var(--navy-sub);
  padding: 44px 0 40px; margin-top: 40px; }
.footer-in { display: flex; align-items: center; gap: 16px; flex-wrap: wrap; }
.footer-in .brand-name { color: var(--navy-text); }
.footer-note { font-size: 13px; }
.footer-right { margin-left: auto; font-size: 12.5px; }

/* ============ 演示页专属 ============ */
.demo-shell {
  background: var(--ink); border-radius: var(--radius);
  padding: 18px; display: grid; grid-template-columns: 1.6fr .9fr; gap: 18px;
}
.demo-stage { position: relative; background: #070d18;
  border-radius: var(--radius-s); overflow: hidden; min-height: 420px; }
.demo-stage video, .demo-stage canvas {
  width: 100%; height: 100%; object-fit: contain; display: block;
}
.demo-stage canvas { position: absolute; inset: 0; }
.demo-alert {
  position: absolute; top: 14px; left: 50%; transform: translateX(-50%);
  padding: 8px 22px; border-radius: 999px; font-weight: 800; font-size: 14px;
  color: var(--green); background: rgba(18, 51, 31, .85);
  border: 1px solid rgba(47, 210, 125, .5); backdrop-filter: blur(4px);
  transition: .25s; z-index: 5; white-space: nowrap;
}
.demo-alert.danger {
  color: #ffd9dd; background: rgba(110, 24, 38, .92);
  border-color: rgba(255, 77, 94, .6);
  animation: pulse .9s infinite;
}
@keyframes pulse { 50% { box-shadow: 0 0 0 10px rgba(255, 77, 94, .12); } }
.demo-panel { display: flex; flex-direction: column; gap: 12px;
  color: var(--navy-sub); font-size: 13.5px; }
.demo-panel .box { background: var(--ink-2); border: 1px solid #22314f;
  border-radius: var(--radius-s); padding: 14px 16px; }
.demo-panel h4 { color: var(--navy-text); font-size: 13px; margin-bottom: 8px; }
.demo-stat { display: flex; justify-content: space-between; padding: 3px 0; }
.demo-stat b { color: var(--navy-text); font-variant-numeric: tabular-nums; }
.demo-btn {
  width: 100%; padding: 11px; border-radius: 10px; border: none;
  font-family: var(--font); font-size: 14px; font-weight: 800;
  cursor: pointer; transition: .15s;
}
.demo-btn.primary { background: var(--orange); color: #fff; }
.demo-btn.primary:hover { background: var(--orange-deep); }
.demo-btn.ghost { background: transparent; color: var(--navy-text);
  border: 1px solid #37486b; }
.demo-btn.ghost:hover { border-color: var(--yellow); color: var(--yellow); }
.demo-btn:disabled { opacity: .45; cursor: not-allowed; }
input[type="range"] { width: 100%; accent-color: var(--orange); }
.statusline { font-size: 12px; color: var(--faint); }

/* ============ 滚动显现 ============ */
.reveal { opacity: 0; transform: translateY(18px); transition: .6s ease; }
.reveal.on { opacity: 1; transform: none; }

/* ============ 响应式 ============ */
@media (max-width: 1050px) {
  .hero-grid { grid-template-columns: 1fr; }
  .metrics { grid-template-columns: repeat(2, 1fr); }
  .flow { grid-template-columns: repeat(2, 1fr); }
  .flow-step::after { content: none; }
  .demo-shell { grid-template-columns: 1fr; }
}
@media (max-width: 760px) {
  .nav, .nav-cta { display: none; }
  .menu-btn { display: block; margin-left: auto; }
  .site-header.open .nav {
    display: flex; flex-direction: column; position: absolute;
    top: 100%; left: 0; right: 0; background: #fff;
    padding: 12px 20px 18px; border-bottom: 1px solid var(--line);
    gap: 2px;
  }
  .site-header.open .nav a { color: var(--text); }
  .site-header.open .nav-cta { display: inline-flex; margin: 8px 0 0; }
  .cards { grid-template-columns: 1fr; }
  .shots { grid-template-columns: 1fr; }
  .section { padding: 52px 0; }
  .hero { padding: 56px 0 44px; }
}
@media (max-width: 480px) {
  .metrics { grid-template-columns: 1fr 1fr; }
  .wrap { padding: 0 18px; }
}