/* 超链接科技官网 · 单一样式文件
   设计基调：白底正文 + 深色首屏，品牌红 #E60012，企微绿仅作状态点缀。 */

:root {
  --red: #E60012;
  --red-deep: #B8000E;
  --ink: #0B0D11;
  --ink-soft: #14181F;
  --text: #1B2029;
  --muted: #5B6472;
  --muted-2: #8A93A0;
  --line: #E7E9EE;
  --line-soft: #F0F2F5;
  --bg: #FFFFFF;
  --bg-soft: #F6F7F9;
  --wx: #07C160;
  --radius: 16px;
  --maxw: 1200px;          /* PC 固定内容宽度：居中显示，两侧留白自动平分 */
  --shadow-s: 0 1px 2px rgba(16, 24, 40, .04);
  --shadow-m: 0 12px 32px rgba(16, 24, 40, .08);
  --shadow-l: 0 24px 64px rgba(16, 24, 40, .12);
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB",
    "Microsoft YaHei", "Noto Sans SC", "Helvetica Neue", Arial, sans-serif;
  font-size: 16px;
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
}

img { max-width: 100%; height: auto; }
a { color: inherit; text-decoration: none; }
h1, h2, h3, h4 { margin: 0 0 .6em; font-weight: 600; line-height: 1.3; letter-spacing: -.01em; }
p { margin: 0 0 1em; }
ul, ol { margin: 0 0 1em; padding-left: 1.2em; }
::selection { background: rgba(230, 0, 18, .14); }

/* 内容容器：PC 固定 1200px 居中（改宽度只需改 --maxw）。
   视口窄于 1200px 时由 body 的 min-width 兜底，宁可横向滚动也不挤压版式；
   平板与手机改回 100% 流式。 */
.wrap { width: var(--maxw); max-width: 100%; margin: 0 auto; padding: 0 24px; }
.sr-only {
  position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px;
  overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; border: 0;
}
.skip {
  position: absolute; left: 12px; top: -60px; z-index: 200;
  background: var(--ink); color: #fff; padding: 10px 16px; border-radius: 8px;
  transition: top .2s;
}
.skip:focus { top: 12px; }

/* ---------- 顶部导航 ---------- */
.site-head {
  position: sticky; top: 0; z-index: 100;
  background: rgba(255, 255, 255, .88);
  backdrop-filter: saturate(1.6) blur(14px);
  -webkit-backdrop-filter: saturate(1.6) blur(14px);
  border-bottom: 1px solid transparent;
  transition: border-color .2s, box-shadow .2s;
}
.site-head.is-stuck { border-bottom-color: var(--line); box-shadow: var(--shadow-s); }
.nav {
  display: flex; align-items: center; gap: 32px;
  height: 68px;
}
.brand { display: flex; align-items: center; gap: 10px; font-size: 16px; font-weight: 600; letter-spacing: -.01em; }
.brand img { width: 30px; height: 30px; }
.nav-links { display: flex; gap: 4px; margin-left: auto; }
.nav-links a {
  padding: 8px 14px; border-radius: 8px; font-size: 15px; color: #333A45;
  transition: background .18s, color .18s;
}
.nav-links a:hover { background: var(--bg-soft); color: var(--ink); }
.nav-links a[aria-current="page"] { color: var(--red); font-weight: 500; }
.nav-cta { margin-left: 8px; }
.nav-toggle {
  display: none; margin-left: auto; width: 42px; height: 42px;
  border: 1px solid var(--line); border-radius: 10px; background: #fff;
  align-items: center; justify-content: center; cursor: pointer;
}
.nav-toggle span, .nav-toggle span::before, .nav-toggle span::after {
  content: ""; display: block; width: 18px; height: 1.5px; background: var(--text);
  position: relative; transition: transform .2s, opacity .2s;
}
.nav-toggle span::before { position: absolute; top: -6px; }
.nav-toggle span::after { position: absolute; top: 6px; }

/* ---------- 按钮 ---------- */
.btn {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 13px 24px; border-radius: 999px;
  background: var(--red); color: #fff; font-size: 15px; font-weight: 500;
  border: 1px solid var(--red); cursor: pointer;
  transition: background .18s, transform .18s, box-shadow .18s;
}
.btn:hover { background: var(--red-deep); border-color: var(--red-deep); transform: translateY(-1px); box-shadow: 0 8px 20px rgba(230, 0, 18, .22); }
.btn.sm { padding: 9px 18px; font-size: 14px; }
.btn-ghost { background: transparent; border-color: rgba(255, 255, 255, .28); color: #fff; }
.btn-ghost:hover { background: rgba(255, 255, 255, .1); border-color: rgba(255, 255, 255, .5); box-shadow: none; }
/* 黑底白字按钮：只用在深色首屏，靠细描边与底色拉开层级，避免整块糊在深色背景上 */
.btn-dark { background: #000; border-color: rgba(255, 255, 255, .24); color: #fff; }
.btn-dark:hover { background: #171B22; border-color: rgba(255, 255, 255, .48); box-shadow: none; }
.btn-line { background: transparent; border-color: var(--line); color: var(--text); }
.btn-line:hover { background: var(--bg-soft); box-shadow: none; border-color: #D5D9E0; }

/* ---------- 通用版式 ---------- */
.section { padding: 92px 0; }
.section.tight { padding: 64px 0; }
.soft { background: var(--bg-soft); }
.eyebrow {
  font-size: 12.5px; letter-spacing: .16em; color: var(--red);
  font-weight: 600; text-transform: uppercase; margin-bottom: 14px;
}
.section-head { max-width: 760px; margin-bottom: 44px; }
.section-head.center { margin-left: auto; margin-right: auto; text-align: center; }
.section-head h2 { font-size: clamp(26px, 3.2vw, 38px); margin-bottom: 14px; }
.section-head p { color: var(--muted); font-size: 16.5px; margin: 0; }
.lead { font-size: 17.5px; color: var(--muted); }

.grid { display: grid; gap: 20px; }
.g2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.g3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.g4 { grid-template-columns: repeat(4, minmax(0, 1fr)); }
.split { display: grid; grid-template-columns: 1fr 1fr; gap: 56px; align-items: center; }
.split.wide-right { grid-template-columns: .9fr 1.1fr; }

.card {
  background: #fff; border: 1px solid var(--line); border-radius: var(--radius);
  padding: 28px; transition: transform .2s, box-shadow .2s, border-color .2s;
}
.card:hover { transform: translateY(-3px); box-shadow: var(--shadow-m); border-color: #DDE1E8; }
.card h3 { font-size: 19px; margin-bottom: 8px; }
.card p { color: var(--muted); font-size: 15px; margin-bottom: 0; }
.card .num {
  font-size: 13px; font-weight: 600; color: var(--red); letter-spacing: .08em;
  font-variant-numeric: tabular-nums; margin-bottom: 12px; display: block;
}
.icon-box {
  width: 44px; height: 44px; border-radius: 12px; background: rgba(230, 0, 18, .07);
  display: flex; align-items: center; justify-content: center; margin-bottom: 16px;
}
.icon-box svg { width: 22px; height: 22px; stroke: var(--red); fill: none; stroke-width: 1.6; }
.card.dark { background: var(--ink); border-color: #1E242D; color: #fff; }
.card.dark p { color: #A8B1BF; }

/* ---------- 首屏 ---------- */
.hero {
  position: relative; overflow: hidden;
  background: var(--ink); color: #fff;
  padding: 96px 0 88px;
}
.hero::before {
  content: ""; position: absolute; inset: -30% 40% 40% -20%;
  background: radial-gradient(60% 60% at 40% 40%, rgba(230, 0, 18, .28), transparent 70%);
  pointer-events: none;
}
.hero::after {
  content: ""; position: absolute; inset: 0;
  background-image: linear-gradient(rgba(255, 255, 255, .035) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, .035) 1px, transparent 1px);
  background-size: 56px 56px;
  mask-image: radial-gradient(70% 70% at 60% 30%, #000, transparent);
  -webkit-mask-image: radial-gradient(70% 70% at 60% 30%, #000, transparent);
  pointer-events: none;
}
.hero .wrap { position: relative; z-index: 2; }
.hero-grid { display: grid; grid-template-columns: 1.02fr .98fr; gap: 48px; align-items: center; }
.hero .eyebrow { color: #FF6B75; }
.hero h1 {
  font-size: clamp(32px, 4.2vw, 52px); line-height: 1.22; letter-spacing: -.02em;
  margin-bottom: 20px;
}
.hero h1 .thin { color: #9AA4B2; font-weight: 400; }
.hero h1 .hl {
  color: #fff;
  background: linear-gradient(transparent 62%, rgba(230, 0, 18, .55) 62%);
}
.hero-sub { font-size: 17.5px; color: #B4BCC8; max-width: 520px; margin-bottom: 32px; }
.hero-actions { display: flex; flex-wrap: wrap; gap: 14px; margin-bottom: 44px; }
.hero-stats { display: flex; gap: 40px; flex-wrap: wrap; }
.hero-stats div strong {
  display: block; font-size: 30px; color: #fff; line-height: 1.2;
  font-variant-numeric: tabular-nums; font-weight: 600;
}
.hero-stats div span { font-size: 13px; color: #8C95A3; }
.hero-note { font-size: 12px; color: #6F7887; margin-top: 18px; }

/* 首屏右侧是「手机 + 悬浮卡」的绝对定位组合，宽度必须固定，
   靠右对齐，避免两块之间被拉开成大片空白 */
.hero-visual {
  position: relative; width: 100%;
  min-height: 510px; max-width: 620px; margin-left: auto;
}
.phone {
  position: absolute; left: 0; top: 10px; width: 232px;
  border-radius: 40px; border: 9px solid #23262C; background: #23262C;
  box-shadow: 0 30px 70px rgba(0, 0, 0, .55);
  overflow: hidden;
}
.phone::after {
  content: ""; position: absolute; left: 50%; top: 8px; transform: translateX(-50%);
  width: 84px; height: 20px; background: #23262C; border-radius: 0 0 12px 12px; z-index: 3;
}
.phone img { display: block; width: 100%; }
.chat-float {
  position: absolute; right: 0; top: 158px; width: 288px;
  background: #fff; border-radius: 14px; padding: 10px;
  box-shadow: var(--shadow-l);
  border: 1px solid rgba(255, 255, 255, .14);
}
.chat-float img { display: block; width: 100%; border-radius: 8px; }
.chat-float figcaption {
  font-size: 12px; color: var(--muted); padding: 8px 4px 2px;
  display: flex; align-items: center; gap: 6px;
}

/* ---------- 截图框 ---------- */
.shot {
  margin: 0; background: #fff; border: 1px solid var(--line); border-radius: 14px;
  padding: 8px; box-shadow: var(--shadow-m);
}
.shot img { display: block; width: 100%; border-radius: 8px; }
.shot figcaption {
  display: flex; align-items: flex-start; gap: 7px;
  font-size: 12.5px; line-height: 1.6; color: var(--muted); padding: 10px 4px 2px;
}
.shot figcaption::before {
  content: ""; flex: none; width: 6px; height: 6px; border-radius: 50%;
  background: var(--red); margin-top: 7px;
}
.shot.plain { border-color: transparent; box-shadow: none; background: transparent; padding: 0; }
.shot.plain figcaption { padding-left: 0; }

/* ---------- 编号步骤 ---------- */
.steps { display: grid; gap: 16px; }
.step { display: flex; gap: 16px; align-items: flex-start; }
.step-n {
  flex: none; width: 30px; height: 30px; border-radius: 50%;
  display: flex; align-items: center; justify-content: center;
  font-size: 13px; font-weight: 600; color: var(--red);
  background: rgba(230, 0, 18, .08); font-variant-numeric: tabular-nums;
}
.step h4 { margin: 2px 0 4px; font-size: 15.5px; }
.step p { margin: 0; font-size: 14px; color: var(--muted); }

/* ---------- 标签 ---------- */
.tags { display: flex; flex-wrap: wrap; gap: 10px; margin: 22px 0 0; }
.tag {
  font-size: 13px; padding: 7px 14px; border-radius: 999px;
  border: 1px solid var(--line); background: #fff; color: #3A424E;
}
.tag.wx { border-color: rgba(7, 193, 96, .3); color: #0B8A47; background: rgba(7, 193, 96, .06); }
.tag.wx::before {
  content: ""; display: inline-block; width: 6px; height: 6px; border-radius: 50%;
  background: var(--wx); margin-right: 7px; vertical-align: 1px;
}

/* ---------- 列表 ---------- */
.checks { list-style: none; padding: 0; margin: 0; display: grid; gap: 12px; }
.checks li { position: relative; padding-left: 26px; color: #333A45; font-size: 15.5px; }
.checks li::before {
  content: ""; position: absolute; left: 2px; top: 9px;
  width: 11px; height: 6px; border-left: 1.6px solid var(--red); border-bottom: 1.6px solid var(--red);
  transform: rotate(-45deg);
}
.checks li b { font-weight: 600; }

/* ---------- 表格 ---------- */
.table-wrap { overflow-x: auto; border: 1px solid var(--line); border-radius: var(--radius); background: #fff; }
table.tb { width: 100%; border-collapse: collapse; font-size: 14.5px; min-width: 560px; }
table.tb th, table.tb td { padding: 14px 18px; text-align: left; border-bottom: 1px solid var(--line-soft); vertical-align: top; }
table.tb th { background: #FBFBFC; font-weight: 500; color: #3A424E; font-size: 13.5px; }
table.tb tr:last-child td { border-bottom: 0; }
table.tb td:first-child { font-weight: 500; white-space: nowrap; }

/* ---------- 场景 / 能力格 ---------- */
.cell {
  border: 1px solid var(--line); border-radius: 12px; padding: 20px 22px; background: #fff;
}
.cell h4 { font-size: 15px; margin-bottom: 6px; }
.cell p { font-size: 13.5px; color: var(--muted); margin: 0; }
.cell .emo { display: none; }

/* ---------- 问答 ---------- */
.faq { border-top: 1px solid var(--line); }
.faq details { border-bottom: 1px solid var(--line); }
.faq summary {
  cursor: pointer; list-style: none; padding: 22px 44px 22px 0; position: relative;
  font-size: 16.5px; font-weight: 500;
}
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after {
  content: ""; position: absolute; right: 8px; top: 50%;
  width: 9px; height: 9px; border-right: 1.6px solid #7A8290; border-bottom: 1.6px solid #7A8290;
  transform: translateY(-70%) rotate(45deg); transition: transform .2s;
}
.faq details[open] summary::after { transform: translateY(-30%) rotate(-135deg); }
.faq .ans { padding: 0 44px 24px 0; color: var(--muted); font-size: 15px; }
.faq .ans p:last-child { margin-bottom: 0; }

/* ---------- 转化 / 二维码 ---------- */
.cta-band {
  background: var(--ink); color: #fff; border-radius: 24px; padding: 56px;
  display: grid; grid-template-columns: 1.1fr .9fr; gap: 48px; align-items: center;
  position: relative; overflow: hidden;
}
.cta-band::before {
  content: ""; position: absolute; right: -10%; top: -40%;
  width: 460px; height: 460px; border-radius: 50%;
  background: radial-gradient(circle, rgba(230, 0, 18, .32), transparent 68%);
}
.cta-band h2 { font-size: clamp(24px, 2.8vw, 34px); margin-bottom: 12px; }
.cta-band p { color: #AEB6C2; margin-bottom: 0; }
.qr {
  background: #fff; border-radius: 18px; padding: 18px; text-align: center;
  position: relative; z-index: 2;
}
.qr img { width: 190px; height: 190px; display: block; margin: 0 auto 10px; }
.qr span { font-size: 13px; color: var(--muted); }

/* ---------- 页脚 ---------- */
.site-foot { background: var(--ink); color: #98A1AE; padding: 64px 0 28px; margin-top: 0; }
.foot-grid { display: grid; grid-template-columns: 1.4fr 1fr 1fr 1fr; gap: 40px; }
.foot-brand { display: flex; align-items: center; gap: 10px; color: #fff; font-size: 15px; margin-bottom: 14px; }
.foot-brand img { width: 28px; height: 28px; }
.site-foot h4 { color: #fff; font-size: 14px; margin-bottom: 14px; }
.site-foot ul { list-style: none; padding: 0; margin: 0; display: grid; gap: 9px; }
.site-foot a { color: #98A1AE; font-size: 14px; transition: color .18s; }
.site-foot a:hover { color: #fff; }
.foot-desc { font-size: 14px; line-height: 1.8; margin: 0; max-width: 320px; }
.legal {
  border-top: 1px solid #1E242D; margin-top: 44px; padding-top: 22px;
  display: flex; flex-wrap: wrap; gap: 10px 22px; align-items: center;
  font-size: 12.5px; color: #6F7887;
}
.legal a { font-size: 12.5px; color: #8C95A3; }
.legal a:hover { color: #fff; }

/* ---------- 滚动进入 ---------- */
.js .reveal { opacity: 0; transform: translateY(14px); transition: opacity .5s ease, transform .5s ease; }
.js .reveal.in { opacity: 1; transform: none; }
@media (prefers-reduced-motion: reduce) {
  .reveal { opacity: 1; transform: none; transition: none; }
  html { scroll-behavior: auto; }
}

/* ---------- 页面头部（子页） ---------- */
.page-hero {
  background: var(--ink); color: #fff; padding: 76px 0 68px; position: relative; overflow: hidden;
}
.page-hero::before {
  content: ""; position: absolute; inset: -40% 45% 30% -15%;
  background: radial-gradient(55% 55% at 40% 40%, rgba(230, 0, 18, .25), transparent 70%);
}
.page-hero .wrap { position: relative; z-index: 2; }
.page-hero .eyebrow { color: #FF6B75; }
.page-hero h1 { font-size: clamp(29px, 3.6vw, 44px); margin-bottom: 16px; letter-spacing: -.02em; }
.page-hero p { color: #B4BCC8; font-size: 17px; max-width: 680px; margin: 0; }
.crumb { font-size: 13px; color: #7A8391; margin-bottom: 18px; }
.crumb a { color: #A9B2BF; }
.crumb a:hover { color: #fff; }
.crumb span { margin: 0 7px; color: #4C5665; }

/* ---------- 响应式 ---------- */
/* PC（≥1025px）：固定 1200px 居中；视口再窄也不压缩栅格，改为整页横向滚动 */
@media (min-width: 1025px) {
  body { min-width: var(--maxw); }
}
@media (max-width: 1024px) {
  .wrap { width: 100%; }
  .hero-grid { grid-template-columns: 1fr; gap: 56px; }
  .hero-visual { min-height: 420px; max-width: 520px; margin: 0 auto; width: 100%; }
  .split, .split.wide-right { grid-template-columns: 1fr; gap: 36px; }
  .g4 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .foot-grid { grid-template-columns: 1fr 1fr; }
  .cta-band { grid-template-columns: 1fr; padding: 40px; }
}
@media (max-width: 860px) {
  .nav-links {
    display: none; position: absolute; left: 0; right: 0; top: 68px;
    background: #fff; border-bottom: 1px solid var(--line);
    flex-direction: column; padding: 12px 20px 20px; gap: 2px;
    box-shadow: 0 18px 32px rgba(16, 24, 40, .08);
  }
  .nav-links.open { display: flex; }
  .nav-links a { padding: 12px 8px; }
  .nav-toggle { display: flex; }
  .nav-cta { display: none; }
  .section { padding: 64px 0; }
  .g3 { grid-template-columns: 1fr; }
  .g2 { grid-template-columns: 1fr; }
  .hero { padding: 64px 0 72px; }
  .hero-stats { gap: 26px; }
  .hero-stats div strong { font-size: 24px; }
  .phone { width: 210px; left: 0; }
  .chat-float { width: 260px; right: 0; top: 130px; }
  .cta-band { padding: 32px 24px; border-radius: 18px; }
  .foot-grid { grid-template-columns: 1fr; gap: 28px; }
}
@media (max-width: 560px) {
  .g4 { grid-template-columns: 1fr; }
  .hero-actions { gap: 10px; }
  .hero-actions .btn { padding: 11px 18px; font-size: 14.5px; }
  .hero-visual { min-height: 0; display: flex; justify-content: center; }
  .phone { position: relative; left: auto; top: 0; width: 218px; margin: 0 auto; }
  .chat-float { display: none; }
  .brand span { display: none; }
  .section-head { margin-bottom: 32px; }
  .card { padding: 22px; }
}