:root {
  --ink:#16171a;
  --text:#3d3e3f;
  --muted:#777;
  --paper:#f7f7f5;
  --line:#dededb;
  --red:#d02928;
}

* {
  box-sizing:border-box;
}

html {
  scroll-behavior:smooth;
  scroll-padding-top:90px;
}

body {
  margin:0;
  color:var(--ink);
  background:white;
  font:16px/1.85 "Source Han Sans SC","Noto Sans CJK SC","Microsoft YaHei",sans-serif;
}

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

button {
  font:inherit;
}

img {
  display:block;
  max-width:100%;
}

.wrap {
  width:min(1240px,90%);
  margin:auto;
}

header {
  border-bottom:1px solid var(--line);
  background:white;
}

.header-inner {
  display:flex;
  align-items:center;
  justify-content:space-between;
  min-height:88px;
  gap:30px;
}

header img {
  width:164px;
}

header nav {
  display:flex;
  gap:28px;
  font-size:14px;
}

.contact-link {
  border:1px solid var(--ink);
  padding:7px 18px;
  font-size:13px;
}

.crumb {
  font-size:12px;
  color:var(--muted);
  padding-top:24px;
}

.hero {
  padding:42px 0 0;
}

.hero-top {
  display:grid;
  grid-template-columns:1.3fr .8fr;
  gap:70px;
  align-items:end;
  padding-bottom:38px;
}

.tag {
  font:12px/1.5 monospace;
  letter-spacing:1.5px;
  color:var(--muted);
}

.tag:before {
  content:"";
  width:23px;
  height:2px;
  background:var(--red);
  display:inline-block;
  vertical-align:middle;
  margin-right:12px;
}

h1 {
  font-size:clamp(36px,4.9vw,66px);
  line-height:1.17;
  letter-spacing:-2px;
  margin:20px 0 0;
  font-weight:900;
}

h1 span,h2 span {
  color:#646668;
}

h2 {
  font-size:38px;
  line-height:1.35;
  letter-spacing:-1px;
  margin:16px 0 0;
}

h3 {
  font-size:23px;
  line-height:1.4;
  margin:10px 0 16px;
}

p {
  color:var(--text);
  margin:12px 0;
}

.button {
  display:inline-block;
  padding:11px 24px;
  border:1px solid var(--ink);
  font-size:14px;
  margin-top:15px;
}

.primary {
  background:var(--red);
  border-color:var(--red);
  color:white;
}

.hero-photo {
  width:100%;
  height:360px;
  object-fit:cover;
  object-position:center 72%;
}

.photo-caption {
  font-size:12px;
  color:var(--muted);
  padding:9px 0 0;
}

.hero-foot {
  display:grid;
  grid-template-columns:repeat(3,1fr);
  border-bottom:1px solid var(--line);
}

.hero-foot a {
  padding:25px 28px;
  border-right:1px solid var(--line);
  display:flex;
  justify-content:space-between;
  font-size:18px;
  font-weight:700;
}

.hero-foot a:first-child {
  padding-left:0;
}

.hero-foot a:last-child {
  border:0;
}

.hero-foot small {
  display:block;
  font:11px monospace;
  color:var(--muted);
  margin-bottom:5px;
}

.subnav {
  position:sticky;
  top:0;
  background:white;
  border-bottom:1px solid var(--line);
  z-index:5;
  overflow:auto;
}

.subnav .wrap {
  display:flex;
  gap:36px;
}

.subnav a {
  white-space:nowrap;
  font-size:13px;
  padding:15px 0;
}

section {
  padding:78px 0;
}

.gray {
  background:var(--paper);
}

.section-head {
  display:grid;
  grid-template-columns:1fr .9fr;
  gap:75px;
  align-items:end;
  margin-bottom:36px;
}

.section-head p {
  margin:0;
}

.scene-cards {
  display:grid;
  grid-template-columns:repeat(3,1fr);
  gap:28px;
}

.scene-card {
  padding:24px 0;
  border-top:1px solid var(--ink);
}

.scene-card p {
  font-size:15px;
}

.scene-card ul {
  padding-left:20px;
  color:var(--text);
  font-size:14px;
}

.scene-card a {
  display:inline-block;
  border-bottom:1px solid var(--ink);
  font-size:14px;
  margin-top:15px;
}

.number {
  font:12px monospace;
  color:var(--muted);
}

.tabs {
  display:flex;
  border-bottom:1px solid var(--line);
  gap:0;
}

.tabs button {
  border:0;
  background:transparent;
  padding:17px 30px;
  cursor:pointer;
  font-size:16px;
}

.tabs button[aria-selected=true] {
  background:var(--ink);
  color:white;
}

.scene-detail {
  display:grid;
  grid-template-columns:1fr 1fr;
  gap:55px;
  padding-top:38px;
}

.scene-detail h3 {
  font-size:29px;
}

.chips {
  display:flex;
  flex-wrap:wrap;
  gap:8px;
  margin:18px 0;
}

.chips span {
  font-size:12px;
  padding:4px 10px;
  border:1px solid #ccc;
}

.tasks {
  display:grid;
  grid-template-columns:1fr 1fr;
  gap:18px 24px;
  margin:28px 0;
}

.task {
  border-top:1px solid #ccc;
  padding-top:13px;
}

.task b {
  font-size:16px;
}

.task p {
  font-size:14px;
  margin:5px 0;
}

.scope {
  font-size:13px;
  color:#666;
  border-left:2px solid #aaa;
  padding-left:16px;
}

.map {
  background:white;
  border:1px solid var(--line);
  padding:20px;
  align-self:start;
}

.map svg {
  width:100%;
  display:block;
}

.map figcaption {
  font-size:12px;
  color:var(--muted);
  margin-top:10px;
}

.map-legend {
  display:flex;
  justify-content:space-between;
  gap:12px;
  font-size:12px;
  border-top:1px solid var(--line);
  padding-top:13px;
}

.capabilities {
  display:grid;
  grid-template-columns:repeat(4,1fr);
  gap:28px;
}

.cap {
  border-top:1px solid #aaa;
  padding-top:22px;
}

.cap p {
  font-size:14px;
}

.architecture {
  margin-top:40px;
  display:grid;
  grid-template-columns:1fr 1fr 1fr;
  gap:1px;
  background:var(--line);
  border:1px solid var(--line);
}

.architecture article {
  background:var(--paper);
  padding:28px;
}

.architecture h3 {
  font-size:20px;
}

.architecture p {
  font-size:14px;
}

.matrix {
  width:100%;
  border-collapse:collapse;
  text-align:left;
  font-size:14px;
}

.matrix th,.matrix td {
  border-bottom:1px solid #ccc;
  padding:19px 22px;
  vertical-align:top;
}

.matrix th {
  color:#16171a;
  background:#eee;
  font-weight:600;
}

.matrix td:first-child {
  font-weight:700;
  white-space:nowrap;
}

.table-scroll {
  overflow-x:auto;
}

.steps {
  display:grid;
  grid-template-columns:repeat(4,1fr);
  gap:28px;
}

.step {
  border-top:1px solid #aaa;
  padding-top:18px;
}

.step p {
  font-size:14px;
}

.delivery {
  display:flex;
  gap:30px;
  align-items:start;
  padding:28px;
  background:var(--paper);
  margin-top:32px;
  font-size:14px;
}

.delivery strong {
  white-space:nowrap;
}

.faq details {
  border-bottom:1px solid #ccc;
  padding:21px 0;
}

.faq summary {
  cursor:pointer;
  font-weight:600;
}

.faq p {
  font-size:15px;
  max-width:950px;
}

.cta {
  background:var(--ink);
  color:white;
}

.cta p {
  color:#ccc;
  max-width:750px;
}

.cta .button {
  border-color:#ddd;
  color:white;
}

.cta-grid {
  display:grid;
  grid-template-columns:1fr auto;
  gap:50px;
  align-items:center;
}

footer {
  padding:28px 0;
  font-size:12px;
  color:#888;
}

.footer-inner {
  display:flex;
  justify-content:space-between;
}

.note {
  font-size:12px;
  color:var(--muted);
  margin-top:18px;
}

a:focus-visible,button:focus-visible,summary:focus-visible {
  outline:2px solid var(--red);
  outline-offset:4px;
}

.mobile-menu {
  display:none;
}

@media(max-width:900px) {
  .hero-top,.section-head {
    gap:30px;
  }
  .hero-photo {
    height:300px;
  }
  .capabilities,.steps {
    grid-template-columns:repeat(2,1fr);
  }
  .scene-detail {
    grid-template-columns:1fr;
    gap:20px;
  }
  .hero h1 {
    font-size:45px;
  }
  .header-inner nav {
    display:none;
  }
  .scene-cards {
    gap:20px;
  }
  .architecture {
    grid-template-columns:1fr;
  }
  .cta-grid {
    grid-template-columns:1fr;
    gap:10px;
  }
  .map {
    margin:0;
  }
  .matrix th,.matrix td {
    padding:15px;
  }
  .hero-foot a {
    padding:20px 16px;
  }
}

@media(max-width:600px) {
  .header-inner {
    min-height:76px;
  }
  header img {
    width:145px;
  }
  .contact-link {
    padding:5px 10px;
  }
  .hero-top,.section-head,.scene-cards {
    grid-template-columns:1fr;
  }
  .hero-top {
    gap:20px;
  }
  .hero h1 {
    font-size:38px;
  }
  .hero {
    padding-top:30px;
  }
  .hero-photo {
    height:230px;
  }
  .hero-foot a {
    font-size:15px;
    padding:18px 10px;
  }
  .hero-foot small {
    font-size:9px;
  }
  .subnav .wrap {
    gap:24px;
  }
  h2 {
    font-size:29px;
  }
  section {
    padding:50px 0;
  }
  .tabs button {
    padding:14px 18px;
    font-size:14px;
  }
  .tasks {
    gap:18px;
  }
  .scene-detail h3 {
    font-size:25px;
  }
  .capabilities,.steps {
    gap:25px 20px;
  }
  .delivery {
    display:block;
    padding:20px;
  }
  .matrix {
    min-width:650px;
  }
  .footer-inner {
    display:block;
  }
  .photo-caption {
    font-size:11px;
  }
}

@media(prefers-reduced-motion:reduce) {
  html {
    scroll-behavior:auto;
  }
}
/* 方案概览：三个介绍上方的配图 */
.scene-cards .overview-card-img {
  display: block;
  width: 100%;
  aspect-ratio: 16 / 9;
  object-fit: cover;
  object-position: center;
  margin-bottom: 24px;
}
/* 模块化拓展 */
#modular-expansion {
  padding: 72px 0;
  background: #fff;
}

#modular-expansion .modular-heading {
  margin-bottom: 32px;
}

#modular-expansion h2 {
  margin: 16px 0 20px;
  font-size: clamp(28px, 3vw, 44px);
  font-weight: 800;
  line-height: 1.3;
  color: #17191c;
}

#modular-expansion .modular-heading p {
  max-width: 1000px;
  margin: 0;
  font-size: 16px;
  line-height: 1.9;
  color: #666;
}

/* 图片与正文等宽，完整显示 */
#modular-expansion .modular-image {
  width: 100%;
  margin: 0;
}

#modular-expansion .modular-image img {
  display: block;
  width: 100%;
  height: auto;
}

@media (max-width: 767px) {
  #modular-expansion {
    padding: 44px 0;
  }

  #modular-expansion .modular-heading {
    margin-bottom: 24px;
  }
}