@charset "UTF-8";

/* 颜色、留白和字阶共用同一组变量。正文优先使用访问设备的系统字体。 */
:root {
  color-scheme: light;
  --ink: #19191c;
  --secondary: #515158;
  --paper: #fff;
  --canvas: #f5f5f7;
  --line: #d6d6db;
  --focus: #0068cf;
  --header-height: 60px;
  --gutter: clamp(1.25rem, 5.6vw, 5.75rem);
  --section-space: clamp(4.5rem, 6.9vw, 7rem);
  --ease: 200ms ease;
  font-family: -apple-system, BlinkMacSystemFont, Inter, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  color: var(--ink);
  background: var(--paper);
}
*, *::after, *::before { box-sizing: border-box; }
html { min-width: 0; scroll-behavior: smooth; }
body { margin: 0; min-width: 0; line-height: 1.6; -webkit-font-smoothing: antialiased; }
body, main, header, footer, main > section { display: flex; flex-direction: column; }
main, section, article, nav, div { min-width: 0; }
h1, h2, h3, p, ol, ul { margin: 0; }
h1, h2, h3 { text-wrap: balance; overflow-wrap: anywhere; }
ol, ul { padding: 0; }
img { display: block; width: 100%; height: auto; }
a { color: inherit; text-decoration: none; }
a, summary { touch-action: manipulation; -webkit-tap-highlight-color: transparent; }
summary { list-style: none; cursor: pointer; }
summary::-webkit-details-marker { display: none; }
summary::marker { content: ""; }
a:focus-visible, summary:focus-visible { outline: 3px solid var(--focus); outline-offset: 4px; }
main:focus { outline: none; }
section[id] { scroll-margin-top: calc(var(--header-height) + .5rem); }
.shell { width: min(calc(100% - var(--gutter) * 2), 82.5rem); margin-inline: auto; }
.section-pad { padding-block: var(--section-space); }
.section-title { font-size: clamp(2.35rem, 3.65vw, 3.7rem); line-height: 1.15; font-weight: 650; letter-spacing: -.055em; }
.skip-link { position: fixed; z-index: 9; top: .5rem; left: 1rem; padding: .65rem 1rem; background: var(--paper); border-radius: .5rem; transform: translateY(-180%); }
.skip-link:focus { transform: translateY(0); }

/* 窄导航使用原生 details，关闭脚本时菜单和所有栏目链接依然可用。 */
.site-header {
  position: sticky;
  top: 0;
  z-index: 5;
  background: rgb(250 250 252 / 96%);
  border-bottom: 1px solid rgb(0 0 0 / 7%);
  -webkit-backdrop-filter: saturate(150%) blur(16px);
  backdrop-filter: saturate(150%) blur(16px);
}
.header-inner, .header-tools, .desktop-nav, .wordmark, .language, .mobile-menu summary {
  display: flex;
  align-items: center;
}
.header-inner { min-height: var(--header-height); justify-content: space-between; gap: 2rem; }
.wordmark {
  min-height: 44px;
  width: fit-content;
  font-family: Inter, Arial, sans-serif;
  font-size: 1.19rem;
  font-weight: 750;
  letter-spacing: .105em;
  line-height: 1;
}
.desktop-nav { margin-left: auto; gap: clamp(1.6rem, 3vw, 3.5rem); }
.desktop-nav a, .mobile-menu nav a, .language, .top-link { min-height: 44px; display: inline-flex; align-items: center; }
.desktop-nav a { font-size: .89rem; color: #333338; transition: color var(--ease); }
.desktop-nav a:hover, .mobile-menu nav a:hover, .top-link:hover, .back-link:hover { color: var(--focus); }
.header-tools { gap: .6rem; }
.language { position: relative; gap: .42rem; padding-inline: .3rem; font-size: .82rem; font-weight: 600; }
.language::before { content: ""; position: absolute; width: 1px; height: 15px; background: var(--line); left: -.95rem; }
.language svg { width: 17px; height: 17px; }
.language:hover { color: var(--focus); }
.mobile-menu { display: none; }
.mobile-menu summary { justify-content: center; width: 44px; height: 44px; border-radius: .4rem; }
.menu-lines, .menu-lines::after { display: block; width: 19px; height: 1.6px; background: var(--ink); }
.menu-lines { position: relative; transform: translateY(-3px); transition: transform var(--ease); }
.menu-lines::after { content: ""; position: absolute; transform: translateY(6px); transition: transform var(--ease); }
.mobile-menu[open] .menu-lines { transform: rotate(45deg); }
.mobile-menu[open] .menu-lines::after { transform: rotate(-90deg); }
.mobile-menu nav {
  position: absolute;
  top: 100%;
  inset-inline: 0;
  display: flex;
  flex-direction: column;
  padding: .5rem var(--gutter) 1.1rem;
  background: #fafafc;
  border-bottom: 1px solid var(--line);
  box-shadow: 0 12px 20px rgb(0 0 0 / 7%);
}
.mobile-menu nav a { font-size: 1rem; }

/* 桌面首屏以原图为焦点，渐变仅用于保证白色标题覆盖在暗部。 */
.hero { position: relative; isolation: isolate; overflow: hidden; justify-content: center; background: #000; color: white; }
.hero-art { position: absolute; z-index: -2; inset: 0; }
.hero-art img { height: 100%; object-fit: cover; object-position: 58% center; }
.hero-art::after {
  content: ""; position: absolute; inset: 0;
  background: linear-gradient(90deg, #000 0%, rgb(0 0 0 / 90%) 23%, rgb(0 0 0 / 50%) 39%, transparent 63%);
}
.hero-inner { display: flex; align-items: center; min-height: clamp(34rem, 44vw, 44rem); padding-block: clamp(3.7rem, 6vw, 6.5rem); }
.hero-copy { display: flex; flex-direction: column; align-items: flex-start; width: min(54%, 43rem); }
.company-line { margin-bottom: 1.1rem; color: #e2e3e7; font-size: clamp(.88rem, 1.1vw, 1.06rem); font-weight: 570; letter-spacing: .04em; }
.hero h1 { display: flex; flex-direction: column; align-items: flex-start; max-width: 100%; font-size: clamp(3.5rem, 5.15vw, 5.5rem); line-height: 1.1; font-weight: 670; letter-spacing: -.052em; }
.hero h1 span { display: block; }
.hero-description { max-width: 25em; margin-top: 1.4rem; color: #e1e2e6; font-size: clamp(1.05rem, 1.3vw, 1.24rem); line-height: 1.7; text-wrap: balance; }
.hero-action {
  display: inline-flex; align-items: center; gap: .8rem; min-height: 46px; width: fit-content;
  padding: .62rem 1.25rem; margin-top: 1.85rem; border-radius: 3rem;
  background: #f8f8fa; color: #161616; font-size: .94rem; line-height: 1.5; font-weight: 600;
  transition: background var(--ease), transform var(--ease);
}
.hero-action svg { width: 18px; height: 18px; transition: transform var(--ease); }
.hero-action:hover { background: #dedee4; }
.hero-action:hover svg { transform: translateX(2px); }
.hero-action:active { transform: scale(.98); }
.hero-action:focus-visible { outline-color: #8bbfff; }
:lang(en) .company-line { font-size: .78rem; letter-spacing: .12em; }
:lang(en) .hero h1 { font-size: clamp(3.5rem, 5.1vw, 5.35rem); line-height: 1; letter-spacing: -.065em; }

/* 三个入口是完整链接。各屏宽使用同一套弹性排版与等高卡片。 */
.business { background: var(--canvas); }
.business-list { display: flex; flex-wrap: wrap; align-items: stretch; gap: clamp(.85rem, 1.45vw, 1.5rem); margin-top: clamp(1.8rem, 2.45vw, 2.8rem); }
.business-card { display: flex; flex: 1 1 0; }
.card-link { display: flex; flex-direction: column; width: 100%; overflow: hidden; border-radius: 1.45rem; background: var(--paper); transition: box-shadow var(--ease); }
.card-link:hover { box-shadow: 0 8px 30px rgb(21 24 37 / 8%); }
.card-picture { overflow: hidden; background: #e5e5e9; aspect-ratio: 1.58; }
.card-picture img { width: 100%; height: 100%; object-fit: cover; transition: transform 350ms ease; }
.card-link:hover img { transform: scale(1.025); }
.card-copy { display: flex; flex: 1; flex-direction: column; align-items: flex-start; padding: clamp(1.35rem, 1.85vw, 1.95rem); }
.card-copy h3 { font-size: clamp(1.28rem, 1.6vw, 1.7rem); line-height: 1.27; font-weight: 650; letter-spacing: -.035em; }
.card-copy p { flex: 1; margin-top: .65rem; color: var(--secondary); font-size: 1rem; line-height: 1.6; }
.circle-link { display: inline-flex; justify-content: center; align-items: center; align-self: flex-end; width: 2.32rem; height: 2.32rem; margin-top: 1.15rem; border-radius: 50%; color: white; background: #27272a; transition: background var(--ease); }
.circle-link svg { width: 19px; height: 19px; }
.card-link:hover .circle-link { background: #005eb6; }
.card-link:active .circle-link { background: #003d79; }

/* 贸易模式保留上、中、下游三段语义，竖屏时连接线相应转为纵向。 */
.model { background: #171a21; color: #f6f7fb; }
.model-intro { display: flex; align-items: flex-end; justify-content: space-between; gap: clamp(2rem, 7vw, 8rem); }
.model-intro > div { flex: 1.3; }
.section-label { margin-bottom: .8rem; font-size: .99rem; line-height: 1.5; font-weight: 600; color: #c2c8d5; }
.model-description { flex: .85; max-width: 32rem; font-size: 1.08rem; line-height: 1.75; color: #d3d5de; }
.stages { display: flex; list-style: none; margin-top: clamp(2.8rem, 4.6vw, 4.8rem); }
.stage { position: relative; display: flex; flex: 1 1 0; flex-direction: column; align-items: flex-start; padding: 1.5rem 2.1rem 0 0; border-top: 1px solid #606571; }
.stage::before { content: ""; position: absolute; top: -4px; left: 0; width: 7px; height: 7px; border-radius: 50%; background: #babfcf; }
.stage:last-child { padding-right: 0; }
.stage-role { color: #c2c8d5; font-size: .9rem; }
.stage h3 { margin-top: .38rem; font-size: clamp(1.4rem, 1.8vw, 1.85rem); line-height: 1.27; font-weight: 600; letter-spacing: -.035em; }
.stage p { max-width: 32em; margin-top: .85rem; color: #d0d2db; font-size: 1rem; line-height: 1.75; }

/* 公司简介与经营理念并列，理念条目支持键盘展开并保留明确的焦点。 */
.about-inner { display: flex; align-items: flex-start; justify-content: space-between; gap: clamp(2.5rem, 8vw, 10rem); }
.about-copy { flex: 1.15; }
.about-lead { margin-top: 1.65rem; max-width: 29em; font-size: clamp(1.2rem, 1.6vw, 1.55rem); font-weight: 550; line-height: 1.6; letter-spacing: -.025em; text-wrap: balance; }
.body-copy { max-width: 41em; margin-top: 1rem; font-size: 1.02rem; line-height: 1.85; color: var(--secondary); }
.philosophy { flex: .85; }
.philosophy > h3 { padding-bottom: .9rem; font-size: 1.05rem; font-weight: 550; color: var(--secondary); }
.value { border-top: 1px solid var(--line); }
.value:last-child { border-bottom: 1px solid var(--line); }
.value summary { display: flex; align-items: center; justify-content: space-between; gap: 1rem; min-height: 58px; padding-block: .75rem; font-size: 1.13rem; font-weight: 600; }
.value summary:hover { color: var(--focus); }
.value-icon { display: inline-flex; align-items: center; justify-content: center; color: var(--secondary); transition: transform var(--ease); }
.value-icon svg { width: 19px; height: 19px; }
.value[open] .value-icon { transform: rotate(45deg); }
.value p { padding: 0 1.75rem 1.25rem 0; color: var(--secondary); font-size: 1rem; line-height: 1.75; }

/* 业务详情复用首页的图片和字阶，各方向以可直接阅读的列表呈现。 */
.detail-head { background: var(--canvas); }
.detail-intro { display: flex; align-items: center; gap: clamp(2rem, 5vw, 5.5rem); padding-block: clamp(2.8rem, 5.5vw, 6rem); }
.detail-copy { flex: 1; }
.back-link, .top-link, .related-link { display: inline-flex; align-items: center; gap: .6rem; min-height: 44px; width: fit-content; }
.back-link { color: var(--secondary); font-size: .95rem; margin-bottom: clamp(1.35rem, 2.4vw, 2.6rem); }
.back-link svg, .top-link svg, .related-link svg { flex-shrink: 0; width: 18px; height: 18px; }
.detail-copy h1 { font-size: clamp(2.6rem, 4.3vw, 4.65rem); line-height: 1.12; font-weight: 650; letter-spacing: -.05em; }
.detail-copy p { max-width: 32em; margin-top: 1.35rem; font-size: clamp(1.06rem, 1.4vw, 1.3rem); line-height: 1.7; color: var(--secondary); }
.detail-picture { flex: 1.05; overflow: hidden; aspect-ratio: 4 / 3; border-radius: 1.45rem; background: #e6e6e9; }
.detail-picture img { height: 100%; object-fit: cover; }
.detail-scope { display: flex; align-items: flex-start; justify-content: space-between; gap: clamp(2rem, 5vw, 5rem); }
.detail-scope h2 { flex: .7; }
.scope-list { display: flex; flex: 1.3; flex-direction: column; list-style: none; }
.scope-list li { display: flex; align-items: baseline; gap: 1.1rem; border-top: 1px solid var(--line); padding-block: .9rem; line-height: 1.55; font-size: 1.11rem; }
.scope-list li::before { content: ""; flex: 0 0 5px; width: 5px; height: 5px; border-radius: 50%; background: #777a84; align-self: flex-start; margin-top: .7em; }
.scope-list li:last-child { border-bottom: 1px solid var(--line); }
.related { background: var(--canvas); padding-block: clamp(2rem, 3.5vw, 4rem); }
.related-inner, .related-links { display: flex; flex-wrap: wrap; align-items: center; gap: 1.6rem; }
.related-inner { justify-content: space-between; }
.related-inner h2 { font-size: 1.4rem; font-weight: 630; letter-spacing: -.03em; }
.related-link { font-size: 1rem; color: var(--focus); }
.related-link:hover { text-decoration: underline; text-underline-offset: .2em; }

/* 页脚和安全区留白均可随文字缩放，不挤压窄屏内容。 */
.site-footer { background: var(--canvas); border-top: 1px solid var(--line); }
.footer-inner { display: flex; align-items: center; justify-content: space-between; gap: 1.2rem; padding-block: 1.8rem max(1.8rem, env(safe-area-inset-bottom)); }
.footer-name { display: flex; flex-direction: column; gap: .2rem; }
.footer-name b { font-size: .91rem; font-weight: 600; }
.footer-name span { font-size: .75rem; letter-spacing: .06em; color: var(--secondary); }
.top-link { font-size: .9rem; white-space: nowrap; }

/* 平板采用两列或三列并允许自动换行，避免卡片和文案在中等宽度被压窄。 */
@media (min-width: 681px) and (max-width: 900px) {
  .business-card { flex: 1 1 calc(50% - 1rem); }
  .business-card:last-child { flex: 0 1 calc(50% - .5rem); }
  .hero-copy { width: 62%; }
  .hero-art::after { background: linear-gradient(90deg, #000 0%, rgb(0 0 0 / 84%) 34%, rgb(0 0 0 / 22%) 65%, transparent 88%); }
  .model-intro, .about-inner { gap: 2.4rem; }
  .stage { padding-right: 1.4rem; }
}
@media (max-width: 760px) {
  .detail-intro, .detail-scope { flex-direction: column; align-items: stretch; }
  .detail-intro { gap: 1.8rem; }
  .detail-picture { flex: none; width: 100%; }
  .back-link { margin-bottom: .8rem; }
  .about-inner { flex-direction: column; align-items: stretch; gap: 2.4rem; }
  .model-intro { flex-direction: column; align-items: flex-start; gap: 1rem; }
  .stages { flex-direction: column; }
  .stage { border-top: 0; border-left: 1px solid #606571; padding: 0 0 1.8rem 1.25rem; }
  .stage::before { left: -4px; top: .55rem; }
  .stage:last-child { padding-bottom: 0; }
  .stage p { max-width: none; margin-top: .5rem; }
}
@media (max-width: 680px) {
  :root { --header-height: 52px; --gutter: clamp(1.2rem, 5.6vw, 2.4rem); --section-space: clamp(3.7rem, 11vw, 5rem); }
  .header-inner { gap: .5rem; }
  .desktop-nav { display: none; }
  .mobile-menu { display: block; }
  .language::before { display: none; }
  .wordmark { font-size: 1.09rem; }
  .hero { justify-content: flex-start; }
  .hero-inner { order: 0; min-height: 0; padding-block: 2.75rem 1.2rem; }
  .hero-copy { width: 100%; }
  .company-line { margin-bottom: 1rem; }
  .hero h1 { font-size: clamp(2.65rem, 8.4vw, 3.9rem); line-height: 1.1; }
  :lang(en) .hero h1 { font-size: clamp(2.85rem, 9.8vw, 4.1rem); }
  .hero-description { max-width: 31em; margin-top: 1.1rem; font-size: 1rem; }
  .hero-action { margin-top: 1.25rem; }
  .hero-art { order: 1; position: relative; z-index: auto; inset: auto; width: 100%; aspect-ratio: 2.45; }
  .hero-art img { object-position: 65% 54%; }
  .hero-art::after { background: linear-gradient(180deg, #000 0%, rgb(0 0 0 / 22%) 27%, transparent 55%); }
  .business-list { flex-direction: column; gap: 1.35rem; }
  .business-card { flex: none; }
  .card-picture { aspect-ratio: 1.75; }
  .card-copy { position: relative; padding: 1.3rem 4.1rem 1.5rem 1.4rem; }
  .card-copy h3 { font-size: 1.42rem; }
  .circle-link { position: absolute; right: 1.1rem; top: 1.25rem; margin: 0; }
  .model-description { font-size: 1rem; }
  .related-inner, .related-links { flex-direction: column; align-items: flex-start; gap: .45rem; }
  .footer-inner { align-items: flex-start; flex-wrap: wrap; }
}
/* 超窄屏下给文字放大保留空间，语言名称和菜单仍各自有独立触控区域。 */
@media (max-width: 420px) {
  .header-inner { width: calc(100% - 32px); gap: 8px; }
  .header-tools { gap: 4px; }
  .language { min-width: 44px; justify-content: center; padding-inline: 2px; }
}
@media (max-width: 360px) {
  .language svg { display: none; }
  .header-inner { flex-wrap: wrap; }
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { transition: none !important; }
}