/* 龙瞳官网一期（单页）样式：全深色、细线插画、细体大字号；系统字体，不加载网络资源 */
:root {
  --night: #070d18;
  --night-2: #0b1424;
  --panel: #0e1a2f;
  --text: #eef2f9;
  --text-2: #a3aec0;
  --text-3: #66738a;
  --line: rgba(255, 255, 255, .09);
  --accent: #4f7dff;
  --accent-hi: #8ea8ff;
  --grad: linear-gradient(90deg, #ff4f8b, #4f7dff 50%, #22d3a6);
  --wrap: 1200px;
  --sans: -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans CJK SC", "Source Han Sans SC", "Segoe UI", "Helvetica Neue", Arial, sans-serif;
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; scroll-padding-top: 72px; background: var(--night); }
body {
  margin: 0; background: var(--night); color: var(--text);
  font: 16px/1.85 var(--sans); font-variant-numeric: tabular-nums;
  -webkit-font-smoothing: antialiased; -moz-osx-font-smoothing: grayscale;
}
img { max-width: 100%; height: auto; display: block; }
figure { margin: 0; }
a { color: inherit; text-decoration: none; }
h1, h2, h3 { margin: 0; font-weight: 600; letter-spacing: .01em; }
p { margin: 0; }
.wrap { max-width: var(--wrap); margin: 0 auto; padding: 0 32px; }

/* 英文小标签 */
.label { font-size: 12px; letter-spacing: .22em; text-transform: uppercase; color: var(--accent-hi); font-weight: 500; }

/* 页头 */
.site-header { position: fixed; inset: 0 0 auto; z-index: 20; transition: background .4s, box-shadow .4s; }
.site-header.scrolled { background: rgba(7, 13, 24, .78); -webkit-backdrop-filter: saturate(140%) blur(14px); backdrop-filter: saturate(140%) blur(14px); box-shadow: 0 1px 0 var(--line); }
.header-inner { display: flex; align-items: center; justify-content: space-between; height: 76px; }
.brand img { height: 40px; width: auto; }
.site-nav { display: flex; align-items: center; gap: 36px; font-size: 14px; letter-spacing: .06em; }
.site-nav a { color: var(--text-2); transition: color .25s; }
.site-nav a:hover { color: #fff; }
.site-nav .nav-cta { color: #fff; border: 1px solid rgba(255,255,255,.22); border-radius: 999px; padding: 7px 18px; }
.site-nav .nav-cta:hover { border-color: rgba(255,255,255,.6); }

/* 首屏 */
.hero {
  position: relative; overflow: hidden; min-height: min(100vh, 1000px); min-height: min(100svh, 1000px);
  display: flex; flex-direction: column; justify-content: center;
  background: radial-gradient(1100px 700px at 76% 40%, #13254a 0%, rgba(19,37,74,0) 70%), var(--night);
  padding: 140px 0 48px;
}
.hero::after { content: ""; position: absolute; inset: auto 0 0; height: 160px; background: linear-gradient(transparent, var(--night)); pointer-events: none; }
.hero-canvas { position: absolute; inset: 0; width: 100%; height: 100%; pointer-events: none; }
.hero::before { content: ""; position: absolute; inset: 0; z-index: 0; background: linear-gradient(90deg, var(--night) 0%, rgba(7,13,24,.55) 38%, rgba(7,13,24,0) 62%); pointer-events: none; }
.hero > .wrap { width: 100%; }
.hero-body { position: relative; z-index: 1; }
.hero h1 { font-size: clamp(42px, 6.4vw, 84px); line-height: 1.12; font-weight: 600; letter-spacing: .02em; margin: 26px 0 26px; }
.hero .lead { font-size: clamp(17px, 1.6vw, 21px); color: var(--text-2); font-weight: 300; letter-spacing: .08em; }
.actions { display: flex; align-items: center; flex-wrap: wrap; gap: 32px; margin-top: 48px; }
.btn { display: inline-block; padding: 13px 30px; border-radius: 999px; font-size: 15px; letter-spacing: .06em; transition: background .25s, box-shadow .25s; }
.btn-primary { background: #fff; color: var(--night); font-weight: 500; }
.btn-primary:hover { box-shadow: 0 0 0 6px rgba(255,255,255,.1); }
.link-arrow { font-size: 15px; color: var(--text); letter-spacing: .06em; }
.link-arrow::after { content: " →"; color: var(--accent-hi); transition: margin .25s; }
.link-arrow:hover::after { margin-left: 4px; }

.stats { position: relative; z-index: 1; display: grid; grid-template-columns: repeat(3, 1fr); margin: 120px 0 0; border-top: 1px solid var(--line); }
.stats > div { padding: 30px 0 0; }
.stats > div + div { padding-left: 36px; border-left: 1px solid var(--line); }
.stats dt { font-size: clamp(32px, 3.8vw, 52px); font-weight: 300; line-height: 1.1; color: #fff; white-space: nowrap; letter-spacing: -.01em; }
.stats dt small { font-size: .42em; margin-left: 4px; color: var(--text-2); letter-spacing: 0; }
.stats dd { margin: 12px 0 0; font-size: 14px; color: var(--text-2); letter-spacing: .04em; }
.stats-note { position: relative; z-index: 1; margin-top: 26px; font-size: 12px; color: var(--text-3); letter-spacing: .03em; }

/* 区块 */
.section { position: relative; padding: 150px 0; }
.section-head { margin-bottom: 72px; }
.section-head h2, .tech h2, .contact h2 { font-size: clamp(30px, 3.6vw, 48px); line-height: 1.28; margin-top: 18px; font-weight: 600; }

/* 产品 */
.product { display: grid; grid-template-columns: 7fr 5fr; gap: 80px; align-items: center; padding: 56px 0; }
.product + .product { border-top: 1px solid var(--line); }
.product.reverse { grid-template-columns: 5fr 7fr; }
.product.reverse .sample { order: 2; }
.sample {
  position: relative; isolation: isolate; aspect-ratio: 4 / 3; border-radius: 28px; overflow: hidden; border: 1px solid var(--line);
  background: radial-gradient(120% 90% at 50% 30%, #13233f 0%, var(--night-2) 70%);
}
.sample-bg {
  position: absolute; inset: 0; width: 100%; height: 100%; object-fit: cover;
  -webkit-mask-image: radial-gradient(115% 100% at 50% 38%, #000 42%, transparent 88%);
  mask-image: radial-gradient(115% 100% at 50% 38%, #000 42%, transparent 88%);
  transition: transform 1.6s cubic-bezier(.2,.7,.2,1);
}
.sample-bg.dim { filter: brightness(.72) saturate(.9); }
.product:hover .sample-bg { transform: scale(1.03); }
.sample::after { content: ""; position: absolute; inset: 0; z-index: 1; background: linear-gradient(180deg, rgba(7,13,24,0) 45%, rgba(7,13,24,.7) 100%); pointer-events: none; }
.sample-tag { position: absolute; top: 22px; left: 24px; z-index: 2; font-size: 11px; letter-spacing: .22em; text-transform: uppercase; color: rgba(255,255,255,.8); padding: 6px 12px; border-radius: 999px; background: rgba(7,13,24,.45); border: 1px solid rgba(255,255,255,.14); -webkit-backdrop-filter: blur(8px); backdrop-filter: blur(8px); }
.sample-inset { position: absolute; right: 5%; bottom: 6%; z-index: 2; width: 42%; margin: 0; border-radius: 14px; overflow: hidden; border: 1px solid rgba(255,255,255,.22); box-shadow: 0 24px 60px rgba(0,0,0,.55); background: var(--night-2); }
.sample-inset img { width: 100%; aspect-ratio: 4 / 3; object-fit: cover; }
.sample-inset.square { width: 32%; }
.sample-inset.square img { aspect-ratio: auto; }
.sample-bg.photo { inset: auto; left: 5%; top: 12%; width: 56%; height: auto; object-fit: contain; -webkit-mask-image: radial-gradient(75% 75% at 50% 50%, #000 60%, transparent 100%); mask-image: radial-gradient(75% 75% at 50% 50%, #000 60%, transparent 100%); }
.product:hover .sample-bg.photo { transform: scale(1.03); }
.sample-inset.small { width: 34%; }
.sample.black { background: radial-gradient(90% 80% at 40% 45%, #0d0d0f 0%, #020203 75%); }
.sample-inset figcaption { font-size: 12px; padding: 8px 12px; color: var(--text-2); letter-spacing: .06em; background: rgba(10,20,38,.92); }
.product h3 { font-size: clamp(26px, 2.6vw, 36px); line-height: 1.3; margin: 18px 0 14px; }
.status { font-size: 14px; color: var(--text-2); letter-spacing: .08em; display: flex; align-items: center; gap: 12px; }
.status::before { content: ""; width: 24px; height: 1px; background: var(--grad); }
.desc { margin-top: 26px; color: var(--text-2); font-size: 16px; }
.items { margin-top: 30px; display: flex; flex-wrap: wrap; gap: 10px 0; font-size: 14px; letter-spacing: .06em; color: var(--text); }
.items span + span::before { content: ""; display: inline-block; width: 1px; height: 12px; background: rgba(255,255,255,.22); margin: 0 16px; vertical-align: -1px; }

/* 技术 */
.tech { background: linear-gradient(180deg, var(--night) 0%, var(--night-2) 18%, var(--night-2) 82%, var(--night) 100%); }
.tech-grid { display: grid; grid-template-columns: 5fr 7fr; gap: 80px; align-items: start; }
.tech .sub { margin-top: 28px; color: var(--text-2); max-width: 20em; }
.layers { list-style: none; margin: 0; padding: 0; }
.layers li { display: grid; grid-template-columns: 56px 190px 1fr; align-items: center; gap: 16px; padding: 26px 0; border-bottom: 1px solid var(--line); }
.layers li:first-child { border-top: 1px solid var(--line); }
.layers h3 span { font-size: 12px; font-weight: 400; color: var(--text-3); letter-spacing: .14em; margin-right: 12px; }
.icon { width: 40px; height: 40px; display: block; }
.layers .icon { width: 44px; height: 44px; padding: 8px; border-radius: 12px; background: rgba(255,255,255,.04); border: 1px solid var(--line); box-sizing: border-box; }
.layers h3 { font-size: 20px; font-weight: 500; }
.layers p { color: var(--text-2); font-size: 15px; }

/* 合作 */
.coop { display: grid; grid-template-columns: repeat(4, 1fr); border-top: 1px solid var(--line); }
.coop > div { padding: 34px 28px 8px 0; }
.coop > div + div { padding-left: 28px; border-left: 1px solid var(--line); }
.coop-top { display: flex; align-items: center; justify-content: space-between; }
.coop-top span { font-size: 13px; color: var(--text-3); letter-spacing: .14em; }
.coop .icon { width: 40px; height: 40px; }
.coop h3 { font-size: 20px; font-weight: 500; margin: 14px 0 10px; }
.coop p { color: var(--text-2); font-size: 15px; }

/* 联系 */
.contact { position: relative; overflow: hidden; padding: 150px 0 130px; background: radial-gradient(900px 520px at 12% 10%, #13254a 0%, rgba(19,37,74,0) 70%), var(--night); border-top: 1px solid var(--line); }
.contact-grid { display: grid; grid-template-columns: 7fr 5fr; gap: 80px; align-items: end; }
.contact h2 { margin-bottom: 44px; }
.contact-mail { font-size: clamp(22px, 2.6vw, 34px); font-weight: 300; letter-spacing: .02em; background: var(--grad) left bottom / 100% 1px no-repeat; padding-bottom: 6px; }
.contact-mail:hover { background-size: 100% 2px; }
.contact-info p { display: grid; grid-template-columns: 64px 1fr; gap: 12px; padding: 16px 0; border-bottom: 1px solid var(--line); font-size: 15px; }
.contact-info span { color: var(--text-3); letter-spacing: .1em; }
.qr { display: flex; align-items: center; gap: 16px; margin-top: 28px; font-size: 13px; color: var(--text-3); letter-spacing: .1em; }
.qr img { border-radius: 8px; }

/* 页脚 */
.site-footer { border-top: 1px solid var(--line); color: var(--text-3); font-size: 12px; letter-spacing: .04em; }
.footer-inner { display: flex; justify-content: space-between; gap: 12px; flex-wrap: wrap; padding: 24px 32px 28px; }
.site-footer a:hover { color: var(--text-2); }

/* 滚动渐显 */
.reveal { opacity: 0; transform: translateY(24px); transition: opacity 1s cubic-bezier(.2,.7,.2,1), transform 1s cubic-bezier(.2,.7,.2,1); }
.reveal.in, .no-js .reveal { opacity: 1; transform: none; }
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .reveal { opacity: 1; transform: none; transition: none; }
}

/* 404 */
.notfound { min-height: 80vh; }
.notfound h1 { font-size: clamp(34px, 4vw, 52px); }

/* 平板 */
@media (max-width: 1000px) {
  .product, .product.reverse { grid-template-columns: 1fr; gap: 40px; }
  .product.reverse .sample { order: 0; }
  .tech-grid, .contact-grid { grid-template-columns: 1fr; gap: 56px; }
  .coop { grid-template-columns: 1fr 1fr; }
  .coop > div:nth-child(3) { padding-left: 0; border-left: 0; }
  .coop > div { padding-bottom: 30px; }
}
/* 手机 */
@media (max-width: 640px) {
  .wrap { padding: 0 22px; }
  .header-inner { height: 64px; }
  .brand img { height: 36px; }
  .site-nav a:not(.nav-cta) { display: none; }
  .hero { padding: 120px 0 36px; justify-content: flex-start; }
  .hero-canvas { opacity: .6; }
  .hero::before { background: linear-gradient(180deg, rgba(7,13,24,0) 0%, rgba(7,13,24,.65) 45%, var(--night) 80%); }
  .actions { gap: 24px; margin-top: 40px; }
  .stats { grid-template-columns: 1fr; margin-top: 80px; }
  .stats > div, .stats > div + div { padding: 22px 0; border-left: 0; border-bottom: 1px solid var(--line); display: flex; justify-content: space-between; align-items: baseline; gap: 12px; }
  .stats dd { margin: 0; text-align: right; }
  .section { padding: 100px 0; }
  .section-head { margin-bottom: 40px; }
  .product { padding: 40px 0; gap: 28px; }
  .sample { border-radius: 18px; }
  .sample-inset { width: 48%; border-radius: 10px; }
  .sample-tag { top: 14px; left: 14px; }
  .layers li { grid-template-columns: 44px 1fr; padding: 22px 0; column-gap: 16px; row-gap: 4px; }
  .layers li .icon { grid-row: span 2; align-self: start; }
  .layers li p { grid-column: 2; }
  .sample-inset.square { width: 38%; }
  .coop { grid-template-columns: 1fr; }
  .coop > div, .coop > div + div { padding: 26px 0 20px; border-left: 0; border-bottom: 1px solid var(--line); }
  .contact { padding: 100px 0 90px; }
}
/* 旧版存档入口（导航右侧，手机上也保留） */
.site-nav .nav-old { font-size: 13px; color: var(--text-3, rgba(255,255,255,.5)); border-left: 1px solid rgba(255,255,255,.16); padding-left: 20px; margin-left: -12px; }
@media (max-width: 640px) {
  .site-nav { gap: 18px; }
  .site-nav a.nav-old { display: inline; border-left: 0; padding-left: 0; margin-left: 0; }
}
/* 左下角第二张小图（V 槽设备照片） */
.sample-inset.device { left: 5%; right: auto; width: 46%; }
.sample-inset.device img { aspect-ratio: 16 / 9; }