@font-face {
  font-family: "Site Serif";
  src: url("fonts/serif-400.woff2") format("woff2");
  font-weight: 400;
  font-display: swap;
}
@font-face {
  font-family: "Site Serif";
  src: url("fonts/serif-600.woff2") format("woff2");
  font-weight: 600;
  font-display: swap;
}

:root {
  --bg: #faf7f5;
  --surface: #f3eee9;
  --ink: #111111;
  --text: #2a2a2a;
  --muted: #595959;
  --line-soft: #ddd6cf;
  /* 页面只用黑白灰；红色（与 BP 同款 #C7171E）只留在 logo、网站图标与首屏方块（main.js）上 */

  --sans: "PingFang SC", "HarmonyOS Sans SC", "MiSans", "Microsoft YaHei", "Noto Sans SC", "Source Han Sans SC", sans-serif;
  --serif: "Site Serif", "Noto Serif SC", "Noto Serif CJK SC", "Source Han Serif SC", "Songti SC", serif;

  --gutter: clamp(16px, 4vw, 48px);
  --max: 1280px;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; scroll-padding-top: 72px; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--serif);
  font-size: 16px;
  line-height: 1.8;
  -webkit-font-smoothing: antialiased;
}

a { color: inherit; }

h1, h2, h3 { color: var(--ink); margin: 0; text-wrap: balance; }
p, figcaption { text-wrap: pretty; }
h1, h2 { font-family: var(--sans); font-weight: 700; letter-spacing: 0.01em; }

.wrap {
  width: 100%;
  max-width: var(--max);
  margin: 0 auto;
  padding: 0 var(--gutter);
}

/* 页头 */
.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  background: color-mix(in srgb, var(--bg) 92%, transparent);
  backdrop-filter: saturate(1.2) blur(8px);
  border-bottom: 1px solid var(--line-soft);
}
.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 60px;
}
.brand { display: block; }
.brand img { display: block; height: 28px; width: auto; }
.nav { display: flex; gap: 28px; font-family: var(--sans); font-size: 16px; }
.nav a { text-decoration: none; color: var(--text); }
.nav a:hover { color: var(--ink); text-decoration: underline; text-underline-offset: 5px; text-decoration-thickness: 1px; }

/* 首屏 */
.hero {
  position: relative;
  overflow: hidden;
  padding: clamp(96px, 16vw, 200px) 0 clamp(40px, 6vw, 88px);
}
.hero-field {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
}
.hero .wrap { position: relative; }
.hero h1 {
  font-size: clamp(44px, 8vw, 96px);
  line-height: 1.12;
}
.nowrap { white-space: nowrap; }  /* 窄屏时只在指定位置折行 */
.tagline {
  margin: 32px 0 0;
  font-family: var(--sans);
  font-weight: 500;
  font-size: clamp(20px, 2.4vw, 30px);
  line-height: 1.5;
  color: var(--ink);
}
.lede {
  max-width: 40em;
  margin: 20px 0 0;
  font-size: clamp(17px, 1.6vw, 20px);
  color: var(--text);
}

/* 通用分区：左大标题，右说明 */
.section-head {
  display: grid;
  grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
  gap: 48px;
  padding-top: clamp(96px, 11vw, 160px);
  padding-bottom: clamp(40px, 5vw, 64px);
}
.section-head h2 { font-size: clamp(34px, 4.4vw, 52px); line-height: 1.2; }
.section-intro p { margin: 0 0 1em; font-size: 17px; }
.section-intro p:last-child { margin-bottom: 0; }
.section-intro a { color: var(--ink); text-underline-offset: 5px; text-decoration-thickness: 1px; }

/* 技术说明下的三栏 */
.points {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: clamp(28px, 4vw, 56px);
  padding-top: clamp(8px, 2vw, 24px);
}
.point-label {
  margin: 0 0 10px;
  font-family: var(--sans);
  font-weight: 600;
  font-size: 17px;
  color: var(--ink);
}
.point p:last-child { margin: 0; font-size: 17px; }

/* 实测指标：两列，数字大、单位小 */
.stats {
  display: grid;
  grid-template-columns: 1fr 1fr;
  column-gap: clamp(32px, 5vw, 72px);
}
.stat {
  padding: 32px 0 44px;
  border-top: 1px solid var(--line-soft);
}
.stat .figure {
  margin: 0 0 14px;
  font-family: var(--sans);
  font-weight: 700;
  font-size: clamp(40px, 4.6vw, 60px);
  line-height: 1.05;
  letter-spacing: -0.01em;
  color: var(--ink);
}
.stat .unit {
  margin-left: 0.18em;
  font-size: 0.42em;
  font-weight: 600;
  letter-spacing: 0;
}
.stat .unit-pre { margin: 0 0.15em 0 0; }
.stat h3 { font-size: 19px; font-weight: 600; line-height: 1.5; }
.stat p:last-child { margin: 8px 0 0; font-size: 16px; color: var(--text); max-width: 34em; }

/* 链接列表：只用浅色横线分隔 */
.rows {
  list-style: none;
  max-width: var(--max);
  margin: 0 auto;
  padding: 0 var(--gutter);
}
.row { border-top: 1px solid var(--line-soft); }
.row:last-child { border-bottom: 1px solid var(--line-soft); }
.row-body {
  display: block;
  padding: 28px 0;
  text-decoration: none;
  max-width: 60em;
}
.row-body h3 { font-size: 21px; font-weight: 600; line-height: 1.5; }
.row-body p { margin: 6px 0 0; color: var(--muted); }
.row:hover h3 { text-decoration: underline; text-underline-offset: 5px; text-decoration-thickness: 1px; }
.row a:focus-visible { outline: 2px solid var(--ink); outline-offset: 4px; }

.footnote {
  margin: 0 auto;
  padding-top: 20px;
  padding-bottom: 0;
  font-size: 14px;
  color: var(--muted);
}

/* 收尾：联系与招聘并排 */
.closing-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: clamp(40px, 6vw, 96px);
  padding-top: clamp(96px, 11vw, 160px);
  padding-bottom: clamp(96px, 11vw, 160px);
}
.closing h2 { font-size: clamp(30px, 3.2vw, 40px); line-height: 1.2; margin-bottom: 16px; }
.closing-col > p { margin: 0; font-size: 17px; max-width: 30em; }
.closing-col > p + p { margin-top: 6px; }
.closing-mail { margin-top: 20px !important; }
.closing-mail a {
  font-family: var(--sans);
  font-size: clamp(20px, 2vw, 26px);
  color: var(--ink);
  text-underline-offset: 6px;
  text-decoration-thickness: 1px;
}
.jobs { list-style: none; margin: 28px 0 0; padding: 0; }
.jobs li { border-top: 1px solid var(--line-soft); }
.jobs li:last-child { border-bottom: 1px solid var(--line-soft); }
.jobs a { display: block; padding: 18px 0; text-decoration: none; }
.job-title { display: block; font-weight: 600; font-size: 19px; color: var(--ink); }
.job-desc { display: block; color: var(--muted); font-size: 15px; }
.jobs a:hover .job-title { text-decoration: underline; text-underline-offset: 5px; text-decoration-thickness: 1px; }
.jobs a:focus-visible { outline: 2px solid var(--ink); outline-offset: 4px; }

/* 页脚 */
.site-footer { border-top: 1px solid var(--line-soft); padding: 28px 0 40px; font-family: var(--sans); font-size: 13px; color: var(--muted); }
.footer-inner { display: flex; justify-content: space-between; gap: 16px; flex-wrap: wrap; }
.footer-inner p { margin: 0; }
.footer-inner a { text-decoration: none; }
.footer-inner a:hover { color: var(--ink); }

/* 窄屏 */
@media (max-width: 860px) {
  .nav { gap: 18px; font-size: 15px; }
  .points { grid-template-columns: 1fr; }
  .closing-grid { grid-template-columns: 1fr; }
  .section-head { grid-template-columns: 1fr; gap: 20px; }
  .stats { grid-template-columns: 1fr; }
  .stat { padding: 28px 0 32px; }
  .row-body { padding: 24px 0; }
  .row-body h3 { font-size: 18px; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
}