/* ============================================================
   互赢信息 · 官网样式 — 深色科技风设计系统
   ============================================================ */
:root {
  --bg: #0a0f1e;
  --bg-soft: #0e1526;
  --surface: rgba(255, 255, 255, 0.03);
  --surface-hover: rgba(255, 255, 255, 0.06);
  --border: rgba(148, 163, 184, 0.15);
  --border-strong: rgba(148, 163, 184, 0.3);
  --text: #e8eef9;
  --text-soft: #aab8cf;
  --muted: #7c8aa5;
  --primary: #3b82f6;
  --cyan: #22d3ee;
  --grad: linear-gradient(100deg, #60a5fa 0%, #22d3ee 100%);
  --glow-blue: rgba(59, 130, 246, 0.35);
  --radius: 14px;
  --container: 1180px;
  --font: -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB",
    "Microsoft YaHei", "Segoe UI", Roboto, sans-serif;
  --mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, monospace;
}

* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
body {
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  line-height: 1.7;
  font-size: 16px;
  overflow-x: hidden;
}
a { color: inherit; text-decoration: none; }
img { display: block; max-width: 100%; }
ul, ol { list-style: none; }

.container { max-width: var(--container); margin: 0 auto; padding: 0 24px; }

/* ---------- 顶部导航 ---------- */
.nav {
  position: fixed; top: 0; left: 0; right: 0; z-index: 100;
  background: rgba(10, 15, 30, 0.82);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border-bottom: 1px solid transparent;
  transition: border-color 0.3s;
}
.nav.scrolled { border-bottom-color: var(--border); }
.nav-inner {
  max-width: var(--container); margin: 0 auto; padding: 0 24px;
  height: 68px; display: flex; align-items: center; justify-content: space-between;
}
.logo { display: flex; align-items: center; gap: 10px; font-weight: 700; font-size: 18px; }
.logo-mark { width: 36px; height: 36px; border-radius: 10px; display: block; flex: none; }
.logo small { font-size: 11px; color: var(--muted); font-weight: 500; letter-spacing: 1px; display: block; line-height: 1; margin-top: 2px; }
.logo-text b { display: block; line-height: 1.2; font-size: 16px; }
.nav-links { display: flex; align-items: center; gap: 34px; }
.nav-links a { color: var(--text-soft); font-size: 15px; transition: color 0.2s; position: relative; }
.nav-links a:hover, .nav-links a.active { color: var(--text); }
.nav-links a.active::after {
  content: ""; position: absolute; left: 0; right: 0; bottom: -6px; height: 2px;
  background: var(--grad); border-radius: 2px;
}
.nav-links a.nav-cta {
  padding: 9px 20px; border-radius: 999px; font-size: 14px; font-weight: 600;
  background: var(--grad); color: #071022; transition: transform 0.2s, box-shadow 0.2s;
}
.nav-links a.nav-cta:hover { transform: translateY(-1px); box-shadow: 0 6px 20px var(--glow-blue); }
.nav-toggle { display: none; background: none; border: none; cursor: pointer; padding: 8px; }
.nav-toggle span { display: block; width: 22px; height: 2px; background: var(--text); margin: 5px 0; border-radius: 2px; transition: 0.3s; }

/* ---------- 导航下拉抽屉（精品案例） ---------- */
.nav-item { position: relative; }
.nav-item > a .caret {
  display: inline-block; font-size: 10px; margin-left: 5px;
  color: var(--muted); transition: transform 0.25s, color 0.25s;
}
.nav-menu {
  position: absolute; top: 100%; left: 50%;
  transform: translateX(-50%) translateY(10px);
  min-width: 252px; padding: 8px; z-index: 110;
  background: rgba(13, 20, 38, 0.97);
  border: 1px solid var(--border); border-radius: 14px;
  box-shadow: 0 20px 50px rgba(0, 0, 0, 0.55);
  opacity: 0; visibility: hidden; pointer-events: none;
  transition: opacity 0.22s, transform 0.22s, visibility 0.22s;
  display: flex; flex-direction: column; gap: 2px;
}
.nav-item::after { content: ""; position: absolute; top: 100%; left: 0; right: 0; height: 16px; }
.nav-item:hover .nav-menu, .nav-item.open .nav-menu {
  opacity: 1; visibility: visible; pointer-events: auto;
  transform: translateX(-50%) translateY(0);
}
.nav-item:hover > a .caret, .nav-item.open > a .caret { transform: rotate(180deg); color: var(--cyan); }
.nav-menu a { display: block; padding: 11px 14px; border-radius: 9px; transition: background 0.2s; }
.nav-menu a:hover { background: var(--surface-hover); }
.nav-menu a b { display: block; font-size: 14px; font-weight: 600; }
.nav-menu a span { font-size: 12px; color: var(--muted); font-family: var(--mono); }

/* ---------- 首屏 Hero ---------- */
.hero {
  position: relative; padding: 170px 0 90px; overflow: hidden;
  background:
    radial-gradient(900px 480px at 75% -10%, rgba(34, 211, 238, 0.13), transparent 60%),
    radial-gradient(800px 500px at 12% 8%, rgba(59, 130, 246, 0.16), transparent 62%),
    var(--bg);
}
.hero::before {
  content: ""; position: absolute; inset: 0; pointer-events: none;
  background-image:
    linear-gradient(rgba(148, 163, 184, 0.05) 1px, transparent 1px),
    linear-gradient(90deg, rgba(148, 163, 184, 0.05) 1px, transparent 1px);
  background-size: 52px 52px;
  mask-image: radial-gradient(ellipse 75% 62% at 50% 0%, #000 55%, transparent 100%);
  -webkit-mask-image: radial-gradient(ellipse 75% 62% at 50% 0%, #000 55%, transparent 100%);
}
.hero-inner { position: relative; text-align: center; }
.hero-kicker {
  display: inline-flex; align-items: center; gap: 8px;
  font-family: var(--mono); font-size: 13px; letter-spacing: 2px; color: var(--cyan);
  border: 1px solid rgba(34, 211, 238, 0.3); background: rgba(34, 211, 238, 0.07);
  padding: 7px 16px; border-radius: 999px; margin-bottom: 28px;
}
.hero-kicker::before { content: ""; width: 7px; height: 7px; border-radius: 50%; background: var(--cyan); box-shadow: 0 0 10px var(--cyan); }
.hero h1 { font-size: clamp(34px, 5.6vw, 58px); line-height: 1.25; font-weight: 800; letter-spacing: 0.5px; }
.hero h1 .grad { background: var(--grad); -webkit-background-clip: text; background-clip: text; color: transparent; }
.hero-sub {
  max-width: 680px; margin: 24px auto 0; color: var(--text-soft); font-size: 17px;
}
.hero-tags { display: flex; flex-wrap: wrap; gap: 10px; justify-content: center; margin-top: 30px; }
.hero-tags span {
  font-size: 13px; color: var(--text-soft); border: 1px solid var(--border);
  background: var(--surface); padding: 6px 14px; border-radius: 999px;
}
.hero-actions { display: flex; gap: 16px; justify-content: center; margin-top: 42px; flex-wrap: wrap; }
.btn {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 13px 30px; border-radius: 10px; font-size: 15px; font-weight: 600;
  transition: transform 0.2s, box-shadow 0.2s, background 0.2s; cursor: pointer; border: none;
}
.btn-primary { background: var(--grad); color: #071022; }
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 10px 30px var(--glow-blue); }
.btn-ghost { background: transparent; color: var(--text); border: 1px solid var(--border-strong); }
.btn-ghost:hover { background: var(--surface-hover); border-color: var(--cyan); }

/* ---------- 数字墙 ---------- */
.stats-band {
  border-top: 1px solid var(--border); border-bottom: 1px solid var(--border);
  background: rgba(255, 255, 255, 0.015);
}
.stats-grid {
  display: grid; grid-template-columns: repeat(6, 1fr); gap: 12px; padding: 40px 0;
}
.stat { text-align: center; padding: 8px 6px; }
.stat b {
  display: block; font-size: clamp(26px, 3vw, 36px); font-weight: 800; line-height: 1.2;
  background: var(--grad); -webkit-background-clip: text; background-clip: text; color: transparent;
  font-variant-numeric: tabular-nums;
}
.stat span { font-size: 13px; color: var(--muted); }

/* ---------- 通用 Section ---------- */
.section { padding: 96px 0; }
.section.alt { background: var(--bg-soft); border-top: 1px solid var(--border); border-bottom: 1px solid var(--border); }
.sec-head { max-width: 720px; margin-bottom: 56px; }
.sec-head.center { margin-left: auto; margin-right: auto; text-align: center; }
.sec-kicker {
  font-family: var(--mono); font-size: 13px; letter-spacing: 3px; color: var(--cyan);
  text-transform: uppercase; display: flex; align-items: center; gap: 12px;
}
.sec-head.center .sec-kicker { justify-content: center; }
.sec-kicker::before { content: ""; width: 26px; height: 1px; background: var(--cyan); }
.sec-title { font-size: clamp(26px, 3.6vw, 38px); font-weight: 800; margin-top: 14px; line-height: 1.35; }
.sec-desc { color: var(--text-soft); margin-top: 14px; font-size: 16px; }

/* ---------- 关于我们 ---------- */
.about-grid { display: grid; grid-template-columns: 1.2fr 1fr; gap: 60px; align-items: center; }
.about-text p { color: var(--text-soft); margin-bottom: 18px; font-size: 16px; }
.about-text p strong { color: var(--text); }
.about-points { display: grid; gap: 14px; }
.about-point {
  display: flex; gap: 14px; align-items: flex-start; padding: 18px 20px;
  background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius);
}
.about-point .ico { font-size: 20px; line-height: 1.5; flex: none; }
.about-point b { display: block; font-size: 15px; }
.about-point span { font-size: 13.5px; color: var(--muted); }

/* ---------- 卡片网格 ---------- */
.grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; }
.grid-4 { display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px; }
.card {
  background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius);
  padding: 28px 26px; transition: transform 0.25s, border-color 0.25s, background 0.25s;
  position: relative; overflow: hidden;
}
.card:hover { transform: translateY(-4px); border-color: rgba(34, 211, 238, 0.45); background: var(--surface-hover); }
.card .ico {
  width: 46px; height: 46px; border-radius: 12px; display: flex; align-items: center; justify-content: center;
  background: rgba(59, 130, 246, 0.14); border: 1px solid rgba(59, 130, 246, 0.3);
  margin-bottom: 18px; font-size: 21px;
}
.card h3 { font-size: 17.5px; font-weight: 700; margin-bottom: 10px; }
.card p { font-size: 14px; color: var(--muted); }
.card .num {
  font-family: var(--mono); font-size: 13px; color: rgba(34, 211, 238, 0.75);
  letter-spacing: 1.5px; margin-bottom: 12px; display: block;
}

/* 业务清单（8项小卡） */
.chips-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 14px; }
.chip-item {
  display: flex; align-items: center; gap: 10px; padding: 15px 18px;
  background: var(--surface); border: 1px solid var(--border); border-radius: 12px;
  font-size: 14.5px; color: var(--text-soft); transition: 0.25s;
}
.chip-item:hover { border-color: rgba(34, 211, 238, 0.45); color: var(--text); background: var(--surface-hover); }
.chip-item::before { content: "◆"; color: var(--cyan); font-size: 10px; }

/* ---------- 技术栈 ---------- */
.stack-grid { display: grid; grid-template-columns: repeat(5, 1fr); gap: 12px; }
.stack-item {
  font-family: var(--mono); font-size: 13.5px; text-align: center; padding: 13px 10px;
  border: 1px solid var(--border); border-radius: 10px; color: var(--text-soft);
  background: var(--surface); transition: 0.25s;
}
.stack-item:hover { color: var(--cyan); border-color: rgba(34, 211, 238, 0.5); }

/* ---------- 案例卡片 ---------- */
.case-card {
  display: grid; grid-template-columns: 1fr 1.15fr; gap: 0;
  background: var(--surface); border: 1px solid var(--border); border-radius: 18px;
  overflow: hidden; transition: transform 0.25s, border-color 0.25s;
}
.case-card:hover { transform: translateY(-5px); border-color: rgba(34, 211, 238, 0.4); }
.case-card + .case-card { margin-top: 34px; }
.case-visual {
  position: relative; background:
    radial-gradient(420px 300px at 60% 40%, rgba(59, 130, 246, 0.2), transparent 70%),
    var(--bg-soft);
  display: flex; align-items: center; justify-content: center; gap: 18px; padding: 42px 30px;
  min-height: 380px;
}
.phone {
  width: 150px; border-radius: 22px; border: 1px solid var(--border-strong);
  background: #000; padding: 8px 7px; box-shadow: 0 18px 50px rgba(0, 0, 0, 0.55);
  position: relative; flex: none;
}
.phone::before {
  content: ""; position: absolute; top: 7px; left: 50%; transform: translateX(-50%);
  width: 52px; height: 5px; border-radius: 4px; background: rgba(255, 255, 255, 0.16); z-index: 2;
}
.phone img { border-radius: 15px; aspect-ratio: 750 / 1600; object-fit: cover; object-position: top; width: 100%; }
.phone.back { transform: translateY(26px) scale(0.88); opacity: 0.5; z-index: 0; }
.case-body { padding: 40px 38px; display: flex; flex-direction: column; }
.case-tag {
  display: inline-flex; align-self: flex-start; font-family: var(--mono); font-size: 12px;
  letter-spacing: 1.5px; color: var(--cyan); border: 1px solid rgba(34, 211, 238, 0.35);
  border-radius: 999px; padding: 4px 12px; margin-bottom: 16px;
}
.case-body h3 { font-size: 22px; font-weight: 800; }
.case-client { color: var(--muted); font-size: 13.5px; margin: 6px 0 14px; }
.case-body p { color: var(--text-soft); font-size: 14.5px; flex: 1; }
.case-metrics { display: flex; flex-wrap: wrap; gap: 22px; margin: 20px 0 22px; }
.case-metrics div b { font-size: 20px; font-weight: 800; display: block; line-height: 1.3; }
.case-metrics div b em { font-style: normal; color: var(--cyan); }
.case-metrics div span { font-size: 12px; color: var(--muted); }
.case-link { font-size: 14.5px; font-weight: 600; color: var(--cyan); display: inline-flex; align-items: center; gap: 6px; }
.case-link:hover { gap: 11px; }
.case-link { transition: gap 0.25s; }

/* 浏览器窗口视觉（PC 后台案例卡片用） */
.browser {
  width: min(100%, 480px);
  border-radius: 12px; border: 1px solid var(--border-strong);
  background: #0d1424; overflow: hidden;
  box-shadow: 0 18px 50px rgba(0, 0, 0, 0.55);
}
.browser-bar {
  display: flex; align-items: center; gap: 6px;
  padding: 9px 12px; background: #131c30; border-bottom: 1px solid var(--border);
}
.browser-bar i { width: 10px; height: 10px; border-radius: 50%; flex: none; }
.browser-bar i:nth-child(1) { background: #ff5f57; }
.browser-bar i:nth-child(2) { background: #febc2e; }
.browser-bar i:nth-child(3) { background: #28c840; }
.browser-url {
  flex: 1; margin-left: 8px; font-family: var(--mono); font-size: 11px;
  color: var(--muted); background: rgba(255, 255, 255, 0.06);
  border-radius: 6px; padding: 4px 10px;
  white-space: nowrap; overflow: hidden; text-overflow: ellipsis;
}
.browser img { display: block; width: 100%; aspect-ratio: 16 / 10; object-fit: cover; object-position: top; }

/* ---------- 联系我们 ---------- */
.contact-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 24px; }
.contact-card {
  background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius);
  padding: 30px;
}
.contact-card h3 { font-size: 17px; margin-bottom: 18px; display: flex; align-items: center; gap: 10px; }
.contact-row { display: flex; gap: 12px; padding: 10px 0; border-bottom: 1px dashed rgba(148, 163, 184, 0.12); font-size: 14.5px; }
.contact-row:last-child { border-bottom: none; }
.contact-row b { color: var(--muted); font-weight: 500; flex: none; width: 74px; }
.contact-row span, .contact-row a, .contact-row address { color: var(--text-soft); }
.contact-row address { font-style: normal; }
.contact-row a:hover { color: var(--cyan); }
.contact-slogan {
  margin-top: 26px; text-align: center; font-size: 15px; color: var(--text-soft);
  letter-spacing: 1px;
}

/* ---------- 常见问题 ---------- */
.faq-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 18px; }
.faq-item {
  background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius);
  padding: 22px 24px; transition: border-color 0.25s, background 0.25s;
}
.faq-item[open] { border-color: rgba(34, 211, 238, 0.45); background: var(--surface-hover); }
.faq-item summary {
  cursor: pointer; list-style: none; font-size: 15.5px; font-weight: 700;
  display: flex; align-items: center; justify-content: space-between; gap: 14px;
}
.faq-item summary::-webkit-details-marker { display: none; }
.faq-item summary::after {
  content: "+"; font-family: var(--mono); color: var(--cyan); font-size: 19px;
  flex: none; line-height: 1; transition: transform 0.25s;
}
.faq-item[open] summary::after { transform: rotate(45deg); }
.faq-a { margin-top: 14px; }
.faq-a p { font-size: 14px; color: var(--muted); line-height: 1.8; }

/* ---------- 页脚 ---------- */
.footer { border-top: 1px solid var(--border); padding: 34px 0 40px; background: #070c18; }
.footer-inner {
  display: flex; justify-content: space-between; align-items: center; gap: 16px; flex-wrap: wrap;
  color: var(--muted); font-size: 13px;
}
.footer-brand { display: inline-flex; align-items: center; gap: 10px; }
.footer-logo { width: 26px; height: 26px; border-radius: 7px; }
.footer-inner a { color: var(--muted); }
.footer-inner a:hover { color: var(--cyan); }

/* ============ 案例详情页 ============ */
.case-hero {
  position: relative; padding: 150px 0 70px; overflow: hidden;
  background:
    radial-gradient(800px 400px at 80% -10%, rgba(34, 211, 238, 0.12), transparent 60%),
    radial-gradient(700px 420px at 8% 0%, rgba(59, 130, 246, 0.15), transparent 62%),
    var(--bg);
  border-bottom: 1px solid var(--border);
}
.breadcrumb { font-size: 13.5px; color: var(--muted); margin-bottom: 22px; }
.breadcrumb a:hover { color: var(--cyan); }
.case-hero-grid { display: grid; grid-template-columns: 1.25fr 1fr; gap: 60px; align-items: center; }
.case-hero h1 { font-size: clamp(28px, 4vw, 42px); font-weight: 800; line-height: 1.3; margin: 14px 0; }
.case-hero .lead { color: var(--text-soft); font-size: 16px; }
.case-hero-tags { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 22px; }
.case-hero-tags span {
  font-size: 13px; color: var(--text-soft); border: 1px solid var(--border);
  padding: 5px 14px; border-radius: 999px; background: var(--surface);
}
.case-hero-stats { display: grid; grid-template-columns: repeat(2, 1fr); gap: 14px; }
.case-hero-stats .stat {
  background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius);
  padding: 22px 16px; text-align: left;
}
.case-hero-stats .stat b { font-size: 26px; }
.case-hero-stats .stat span { font-size: 12.5px; }

/* 详情页内容排版 */
.prose-block { max-width: 860px; }
.prose-block p { color: var(--text-soft); margin-bottom: 16px; }
.prose-block strong { color: var(--text); }

/* 流程时间线 */
.flow { display: grid; grid-template-columns: repeat(4, 1fr); gap: 16px; counter-reset: flow; }
.flow-item {
  position: relative; background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--radius); padding: 22px 20px 18px; counter-increment: flow;
}
.flow-item::before {
  content: "0" counter(flow); font-family: var(--mono); font-size: 13px; color: var(--cyan);
  letter-spacing: 1px; display: block; margin-bottom: 10px;
}
.flow-item b { display: block; font-size: 15px; margin-bottom: 6px; }
.flow-item span { font-size: 13px; color: var(--muted); }

/* 双列信息卡（端与角色） */
.role-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 20px; }
.role-card { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 26px; }
.role-card .rk {
  font-family: var(--mono); font-size: 12px; color: var(--cyan); letter-spacing: 1.5px;
  border: 1px solid rgba(34, 211, 238, 0.35); display: inline-block; border-radius: 999px;
  padding: 3px 11px; margin-bottom: 14px;
}
.role-card h3 { font-size: 18px; margin-bottom: 10px; }
.role-card p { font-size: 14px; color: var(--muted); margin-bottom: 12px; }
.role-card ul { display: grid; gap: 7px; }
.role-card li { font-size: 13.5px; color: var(--text-soft); padding-left: 16px; position: relative; }
.role-card li::before { content: "▸"; position: absolute; left: 0; color: var(--cyan); font-size: 12px; }

/* 亮点列表 */
.hl-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 18px; }
.hl-item { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 24px; display: flex; gap: 16px; }
.hl-item .ico { font-size: 22px; flex: none; line-height: 1.5; }
.hl-item b { display: block; font-size: 15.5px; margin-bottom: 6px; }
.hl-item span { font-size: 13.5px; color: var(--muted); }

/* 技术标签组 */
.tech-group { margin-bottom: 26px; }
.tech-group h4 { font-size: 15px; color: var(--text); margin-bottom: 12px; }
.tech-group h4 span { color: var(--muted); font-weight: 400; font-size: 13px; }
.tech-tags { display: flex; flex-wrap: wrap; gap: 10px; }
.tech-tags span {
  font-family: var(--mono); font-size: 13px; color: var(--text-soft);
  border: 1px solid var(--border); background: var(--surface);
  padding: 6px 14px; border-radius: 8px;
}

/* ---------- 截图画廊 ---------- */
.gallery-group { margin-bottom: 60px; }
.gallery-group-head {
  display: flex; align-items: baseline; gap: 14px; margin-bottom: 24px;
  border-bottom: 1px solid var(--border); padding-bottom: 14px;
}
.gallery-group-head h3 { font-size: 19px; }
.gallery-group-head span { font-size: 13px; color: var(--muted); font-family: var(--mono); letter-spacing: 1px; }
.gallery {
  display: grid; grid-template-columns: repeat(6, 1fr); gap: 14px;
}
.shot { position: relative; border-radius: 12px; overflow: hidden; cursor: zoom-in; border: 1px solid var(--border); background: var(--bg-soft); transition: 0.25s; }
.shot:hover { border-color: rgba(34, 211, 238, 0.55); transform: translateY(-3px); box-shadow: 0 12px 32px rgba(0, 0, 0, 0.45); }
.shot img { width: 100%; aspect-ratio: 750 / 1600; object-fit: cover; object-position: top; transition: transform 0.35s; }
.shot:hover img { transform: scale(1.04); }
.shot figcaption {
  position: absolute; left: 0; right: 0; bottom: 0; padding: 26px 10px 9px;
  background: linear-gradient(transparent, rgba(4, 8, 18, 0.92));
  font-size: 12px; color: var(--text-soft); text-align: center; white-space: nowrap;
  overflow: hidden; text-overflow: ellipsis;
}

/* 横屏截图画廊（PC 后台截图，2 列 16:10） */
.gallery-wide { display: grid; grid-template-columns: repeat(2, 1fr); gap: 16px; }
.shot-wide img { aspect-ratio: 16 / 10; object-fit: cover; object-position: top; }

/* ---------- 灯箱 ---------- */
.lightbox {
  position: fixed; inset: 0; z-index: 200; display: none;
  background: rgba(4, 7, 15, 0.94); backdrop-filter: blur(6px); -webkit-backdrop-filter: blur(6px);
  flex-direction: column;
}
.lightbox.open { display: flex; }
.lb-topbar {
  display: flex; justify-content: space-between; align-items: center;
  padding: 16px 22px; flex: none;
}
.lb-caption { font-size: 14.5px; color: var(--text); font-weight: 600; }
.lb-counter { font-family: var(--mono); font-size: 13px; color: var(--muted); margin-left: 16px; }
.lb-close, .lb-prev, .lb-next {
  background: var(--surface-hover); border: 1px solid var(--border); color: var(--text);
  width: 42px; height: 42px; border-radius: 50%; font-size: 18px; cursor: pointer;
  display: flex; align-items: center; justify-content: center; transition: 0.2s;
}
.lb-close:hover, .lb-prev:hover, .lb-next:hover { border-color: var(--cyan); color: var(--cyan); }
.lb-body {
  flex: 1; display: flex; align-items: center; justify-content: center;
  padding: 0 70px 26px; min-height: 0;
}
.lb-body img {
  max-height: 100%; max-width: 100%; height: auto; border-radius: 10px;
  border: 1px solid var(--border-strong); box-shadow: 0 20px 80px rgba(0, 0, 0, 0.6);
  object-fit: contain;
}
.lb-body.scrollable { overflow-y: auto; display: block; padding: 0 70px 26px; }
.lb-body.scrollable img { margin: 0 auto; }
.lb-prev, .lb-next { position: absolute; top: 50%; transform: translateY(-50%); }
.lb-prev { left: 16px; } .lb-next { right: 16px; }
.lb-hint { text-align: center; color: var(--muted); font-size: 12px; padding-bottom: 12px; font-family: var(--mono); }

/* ---------- 上/下案例导航 ---------- */
.case-nav { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; }
.case-nav a {
  border: 1px solid var(--border); border-radius: var(--radius); padding: 24px 26px;
  background: var(--surface); transition: 0.25s; display: block;
}
.case-nav a:hover { border-color: rgba(34, 211, 238, 0.45); background: var(--surface-hover); }
.case-nav .dir { font-family: var(--mono); font-size: 12px; color: var(--muted); letter-spacing: 1.5px; display: block; margin-bottom: 8px; }
.case-nav b { font-size: 16.5px; }
.case-nav a.next { text-align: right; }

/* ---------- 滚动渐显 ---------- */
.reveal { opacity: 0; transform: translateY(26px); transition: opacity 0.7s ease, transform 0.7s ease; }
.reveal.in { opacity: 1; transform: none; }
.reveal.d1 { transition-delay: 0.08s; } .reveal.d2 { transition-delay: 0.16s; } .reveal.d3 { transition-delay: 0.24s; }

/* ---------- 响应式 ---------- */
@media (max-width: 1024px) {
  .stats-grid { grid-template-columns: repeat(3, 1fr); gap: 24px 12px; }
  .grid-4 { grid-template-columns: repeat(2, 1fr); }
  .stack-grid { grid-template-columns: repeat(4, 1fr); }
  .gallery { grid-template-columns: repeat(4, 1fr); }
  .flow { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 860px) {
  .faq-grid { grid-template-columns: 1fr; }
  .nav-links {
    position: fixed; top: 68px; left: 0; right: 0; flex-direction: column; gap: 0;
    background: rgba(10, 15, 30, 0.97); border-bottom: 1px solid var(--border);
    padding: 10px 24px 20px; display: none;
  }
  .nav-links.open { display: flex; }
  .nav-links a { display: block; width: 100%; padding: 13px 0; text-align: center; border-bottom: 1px dashed rgba(148, 163, 184, 0.12); }
  .nav-links a.nav-cta { width: auto; align-self: center; padding: 12px 38px; margin: 14px 0 6px; border-bottom: none; }
  .nav-toggle { display: block; }
  .nav-item { width: 100%; }
  .nav-item::after { display: none; }
  .nav-menu {
    position: static; transform: none; min-width: 0; z-index: auto;
    background: transparent; border: none; box-shadow: none; border-radius: 0;
    opacity: 1; visibility: visible; pointer-events: auto;
    display: none; padding: 0;
  }
  /* 覆盖桌面端展开态的 translateX(-50%) 定位（优先级高于 .nav-menu 基础规则） */
  .nav-item:hover .nav-menu, .nav-item.open .nav-menu {
    position: static; transform: none; opacity: 1; visibility: visible;
  }
  .nav-item.open .nav-menu { display: flex; }
  .nav-menu a { display: block; padding: 11px 0; text-align: center; border-radius: 0; border-bottom: 1px dashed rgba(148, 163, 184, 0.12); }
  .nav-menu a:last-child { border-bottom: none; }
  .hero { padding: 130px 0 70px; }
  .about-grid, .contact-grid, .case-hero-grid, .role-grid, .hl-grid, .case-nav { grid-template-columns: 1fr; }
  .case-card { grid-template-columns: 1fr; }
  .case-visual { min-height: 300px; padding: 34px 20px; }
  .gallery-wide { grid-template-columns: 1fr; }
  .case-body { padding: 28px 24px 32px; }
  .grid-3 { grid-template-columns: 1fr; }
  .section { padding: 70px 0; }
  .lb-body { padding: 0 12px 20px; }
  .lb-prev { left: 8px; } .lb-next { right: 8px; }
  .case-nav a.next { text-align: left; }
}
@media (max-width: 560px) {
  .stats-grid { grid-template-columns: repeat(2, 1fr); }
  .chips-grid { grid-template-columns: repeat(2, 1fr); }
  .stack-grid { grid-template-columns: repeat(2, 1fr); }
  .gallery { grid-template-columns: repeat(3, 1fr); gap: 10px; }
  .flow { grid-template-columns: 1fr; }
  .case-hero-stats { grid-template-columns: repeat(2, 1fr); }
  .case-metrics { gap: 14px; }
}

/* 减少动效偏好 */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .reveal { opacity: 1; transform: none; transition: none; }
}