/* 今探科技官网：深海蓝 + 品牌蓝，大留白、细线条，克制使用阴影与色块。 */
:root {
  --blue: #1f5eff;
  --blue-dark: #1449d6;
  --blue-soft: #eef3ff;
  --cyan: #2fd5c3;
  --navy: #071430;
  --navy-2: #0c1f45;
  --ink: #0f1b33;
  --text: #4a5873;
  --muted: #647089;
  --line: #e7ecf4;
  --bg: #f6f8fc;
  --white: #fff;
  --radius: 16px;
  --shadow: 0 24px 60px -24px rgba(12, 31, 69, .28);
  --top: 72px;
  --wrap: 1200px;
  font-family: "PingFang SC", "HarmonyOS Sans SC", "Microsoft YaHei", "Noto Sans SC", system-ui, sans-serif;
  color: var(--text);
  -webkit-font-smoothing: antialiased;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: var(--top); }
body { margin: 0; background: var(--white); font-size: 16px; line-height: 1.75; }
img { max-width: 100%; height: auto; display: block; }
a { color: inherit; text-decoration: none; }
h1, h2, h3, h4, p { margin: 0; }
ul, ol { margin: 0; padding: 0; list-style: none; }
.i { flex: none; }
:focus-visible { outline: 2px solid #7aa2ff; outline-offset: 3px; border-radius: 6px; }

.skip {
  position: absolute;
  left: -999px;
  top: 8px;
  z-index: 100;
  padding: 8px 16px;
  background: var(--white);
  color: var(--blue);
}
.skip:focus { left: 8px; }

/* 按钮 */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  height: 44px;
  padding: 0 24px;
  border-radius: 999px;
  border: 1px solid transparent;
  font-size: 15px;
  font-weight: 600;
  letter-spacing: .02em;
  white-space: nowrap;
  transition: background .25s, color .25s, border-color .25s, box-shadow .25s;
}
.btn-sm { height: 38px; padding: 0 20px; font-size: 14px; }
.btn-lg { height: 52px; padding: 0 32px; font-size: 16px; }
.btn-primary { background: var(--blue); color: var(--white); }
.btn-primary:hover { background: var(--blue-dark); box-shadow: 0 12px 28px -10px rgba(31, 94, 255, .7); }
.btn-glass { color: var(--white); border-color: rgba(255, 255, 255, .35); background: rgba(255, 255, 255, .06); backdrop-filter: blur(8px); }
.btn-glass:hover { background: rgba(255, 255, 255, .16); border-color: rgba(255, 255, 255, .6); }
.btn-white { background: var(--white); color: var(--navy); }
.btn-white:hover { background: #e9efff; }
.btn-line { color: var(--ink); border-color: #cdd6e6; }
.btn-line:hover { color: var(--blue); border-color: var(--blue); }

/* 顶栏 */
.topbar {
  position: fixed;
  inset: 0 0 auto;
  z-index: 50;
  height: var(--top);
  background: linear-gradient(180deg, rgba(7, 20, 48, .6) 0%, rgba(7, 20, 48, 0) 100%);
  border-bottom: 1px solid rgba(255, 255, 255, .08);
  transition: background .3s, border-color .3s, box-shadow .3s;
}
/* 首屏上透明白字，滚动离开首屏后变白底（site.js 切换 solid） */
.topbar.solid {
  background: rgba(255, 255, 255, .9);
  backdrop-filter: saturate(1.6) blur(14px);
  border-bottom-color: rgba(231, 236, 244, .9);
  box-shadow: 0 6px 24px -18px rgba(12, 31, 69, .4);
}
.topbar:not(.solid) .brand-name,
.topbar:not(.solid) .menu-btn { color: var(--white); }
.topbar:not(.solid) .topnav a { color: rgba(255, 255, 255, .86); }
.topbar:not(.solid) .topnav a:hover,
.topbar:not(.solid) .topnav a.active { color: var(--white); }
.topbar:not(.solid) .topnav a::after { background: var(--cyan); }
.topbar:not(.solid) .btn-line { color: var(--white); border-color: rgba(255, 255, 255, .45); }
.topbar:not(.solid) .btn-line:hover { background: rgba(255, 255, 255, .14); border-color: var(--white); }
.topbar-inner {
  height: 100%;
  max-width: 1440px;
  margin: 0 auto;
  padding: 0 40px;
  display: flex;
  align-items: center;
  gap: 40px;
}
.brand { display: flex; align-items: center; gap: 10px; flex: none; }
.brand img { width: 32px; height: 32px; object-fit: contain; }
.brand-name { font-size: 18px; font-weight: 700; color: var(--ink); letter-spacing: .02em; }
.topnav { display: flex; gap: 8px; margin-left: auto; }
.topnav a {
  position: relative;
  padding: 8px 14px;
  font-size: 15px;
  color: var(--text);
  white-space: nowrap;
  transition: color .2s;
}
.topnav a:hover, .topnav a.active { color: var(--ink); }
.topnav a::after {
  content: "";
  position: absolute;
  left: 50%;
  bottom: -16px;
  width: 0;
  height: 2px;
  background: var(--blue);
  transition: width .25s, left .25s;
}
.topnav a.active::after { left: 14px; width: calc(100% - 28px); }
.top-actions { display: flex; gap: 8px; align-items: center; }
.menu-btn {
  display: none;
  width: 40px;
  height: 40px;
  border: 0;
  background: none;
  color: var(--ink);
  cursor: pointer;
}

/* 通用 */
.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-size: 12px;
  font-weight: 700;
  letter-spacing: .24em;
  color: var(--blue);
}
.eyebrow::before { content: ""; width: 24px; height: 1px; background: currentColor; }
.section { padding: 128px 56px; }
.section > * { max-width: var(--wrap); margin-left: auto; margin-right: auto; }
.sec-head { text-align: center; margin-bottom: 72px; }
.sec-head .eyebrow::after { content: ""; width: 24px; height: 1px; background: currentColor; }
.sec-head h2 {
  margin-top: 18px;
  font-size: clamp(28px, 3.2vw, 42px);
  line-height: 1.3;
  font-weight: 700;
  color: var(--ink);
  letter-spacing: .02em;
}
.sec-head p { margin-top: 16px; font-size: 17px; color: var(--muted); }
.sec-head.light h2 { color: var(--white); }
.sec-head.light p { color: #9fb0d0; }
.sec-head.light .eyebrow { color: var(--cyan); }

/* 首屏 */
.hero {
  position: relative;
  min-height: min(860px, 100vh);
  padding-top: var(--top);
  display: flex;
  flex-direction: column;
  justify-content: center;
  overflow: hidden;
  background: var(--navy);
  color: var(--white);
}
.hero-bg {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: 70% 40%;
}
.hero::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: 1;
  background:
    linear-gradient(90deg, rgba(7, 20, 48, .96) 0%, rgba(7, 20, 48, .86) 34%, rgba(7, 20, 48, .35) 68%, rgba(7, 20, 48, .15) 100%),
    linear-gradient(0deg, rgba(7, 20, 48, .9) 0%, rgba(7, 20, 48, 0) 38%);
}
.hero-inner {
  position: relative;
  z-index: 2;
  width: 100%;
  max-width: var(--wrap);
  margin: 0 auto;
  padding: 96px 0 180px;
}
.hero-eyebrow {
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 14px;
  letter-spacing: .12em;
  color: #b8c8ea;
}
.hero-eyebrow span { width: 32px; height: 1px; background: var(--cyan); }
.hero h1 {
  max-width: 760px;
  margin-top: 28px;
  font-size: clamp(38px, 4.8vw, 64px);
  line-height: 1.22;
  font-weight: 700;
  letter-spacing: .03em;
  text-wrap: balance;
}
.hero h1 span { display: block; }
.hero h1 span + span {
  background: linear-gradient(90deg, #fff 0%, #bcd3ff 60%, #8ff0e4 100%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
/* 首屏右侧的产品界面卡片 */
.hero-visual {
  position: absolute;
  z-index: 2;
  right: max(56px, calc((100% - var(--wrap)) / 2));
  top: 50%;
  width: min(440px, 34vw);
  margin: 0;
  transform: translateY(-58%) perspective(1400px) rotateY(-10deg) rotateX(3deg);
  padding: 10px;
  border-radius: 18px;
  background: rgba(255, 255, 255, .1);
  border: 1px solid rgba(255, 255, 255, .22);
  backdrop-filter: blur(10px);
  box-shadow: 0 40px 80px -30px rgba(0, 0, 0, .6);
}
.hero-visual img { border-radius: 10px; }
.hero-visual figcaption {
  position: absolute;
  left: -28px;
  bottom: 28px;
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 10px 16px;
  border-radius: 12px;
  background: var(--white);
  color: var(--ink);
  font-size: 14px;
  font-weight: 600;
  box-shadow: 0 18px 40px -16px rgba(0, 0, 0, .45);
}
.hero-visual .dot { width: 8px; height: 8px; border-radius: 50%; background: var(--cyan); box-shadow: 0 0 0 4px rgba(47, 213, 195, .2); }
.hero-sub { max-width: 600px; margin-top: 28px; font-size: 18px; line-height: 1.9; color: #c4d1ea; }
.hero-cta { display: flex; flex-wrap: wrap; align-items: center; gap: 16px; margin-top: 48px; }
.hero-hotline {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin-left: 12px;
  font-size: 17px;
  font-weight: 600;
  letter-spacing: .04em;
  color: var(--white);
  font-variant-numeric: tabular-nums;
}
.hero-hotline .i { color: var(--cyan); }
.hero-stats {
  position: absolute;
  z-index: 2;
  left: 50%;
  bottom: 0;
  transform: translateX(-50%);
  width: min(var(--wrap), calc(100% - 112px));
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  border-top: 1px solid rgba(255, 255, 255, .14);
}
.hero-stats li { padding: 32px 0 40px; }
.hero-stats li + li { padding-left: 32px; border-left: 1px solid rgba(255, 255, 255, .1); }
.hero-stats strong {
  display: block;
  font-size: 34px;
  line-height: 1.2;
  font-weight: 700;
  letter-spacing: .02em;
  color: var(--white);
}
.hero-stats span { display: block; margin-top: 6px; font-size: 14px; letter-spacing: .06em; color: #93a6cc; }

/* 解决方案对比 */
.compare { display: grid; grid-template-columns: 1fr 1.25fr; border-radius: 24px; overflow: hidden; box-shadow: var(--shadow); }
.compare-col { padding: 56px; }
.compare-col.before { background: var(--bg); }
.compare-col.after {
  background: linear-gradient(135deg, var(--navy-2) 0%, #133a8a 100%);
  color: var(--white);
}
.compare-label { display: block; margin-bottom: 28px; font-size: 14px; font-weight: 600; letter-spacing: .12em; color: var(--muted); }
.after .compare-label { color: var(--cyan); }
.compare-col li { padding: 20px 0; }
.compare-col li + li { border-top: 1px solid var(--line); }
.after li { display: flex; gap: 16px; }
.after li + li { border-top-color: rgba(255, 255, 255, .1); }
.compare-col h3 { font-size: 17px; font-weight: 600; color: #5d6880; }
.after h3 { color: var(--white); font-size: 18px; }
.compare-col p { margin-top: 4px; font-size: 14px; color: var(--muted); }
.after p { color: #a9bbdf; }
.tick {
  flex: none;
  display: grid;
  place-items: center;
  width: 26px;
  height: 26px;
  margin-top: 1px;
  border-radius: 50%;
  background: rgba(47, 213, 195, .16);
  color: var(--cyan);
}

/* 核心能力 */
.features { background: var(--bg); }
.feature {
  display: grid;
  grid-template-columns: 1.15fr 1fr;
  gap: 88px;
  align-items: center;
}
.feature + .feature { margin-top: 140px; }
.feature.reverse { grid-template-columns: 1fr 1.15fr; }
.feature.reverse .feature-media { order: 2; }
.feature-media { position: relative; padding: 0 0 56px; }
.feature-photo { width: 86%; aspect-ratio: 4 / 3; object-fit: cover; border-radius: 20px; }
.feature.reverse .feature-photo { margin-left: auto; }
.feature-mock {
  position: absolute;
  right: 0;
  bottom: 0;
  width: 60%;
  border-radius: 14px;
  box-shadow: 0 30px 70px -20px rgba(7, 20, 48, .45);
}
.feature.reverse .feature-mock { right: auto; left: 0; }
.feature-no {
  display: block;
  font-size: 72px;
  line-height: 1;
  font-weight: 700;
  background: linear-gradient(180deg, rgba(31, 94, 255, .3), rgba(31, 94, 255, 0));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  font-variant-numeric: tabular-nums;
}
.feature-tag { display: block; margin-top: 20px; font-size: 14px; font-weight: 600; letter-spacing: .16em; color: var(--blue); }
.feature-soon {
  display: inline-block;
  margin-left: 12px;
  padding: 2px 10px;
  border: 1px solid var(--blue);
  border-radius: 999px;
  font-size: 12px;
  font-style: normal;
  font-weight: 600;
  letter-spacing: .04em;
  vertical-align: 1px;
}
.feature-body h3 { margin-top: 10px; font-size: 34px; line-height: 1.3; font-weight: 700; color: var(--ink); letter-spacing: .02em; }
.feature-lead { margin-top: 18px; font-size: 16px; line-height: 1.9; color: var(--text); }
.feature-points { margin-top: 36px; border-top: 1px solid var(--line); }
.feature-points li { display: flex; align-items: center; gap: 16px; padding: 18px 0; border-bottom: 1px solid var(--line); }
.pt-icon { flex: none; display: grid; place-items: center; width: 40px; height: 40px; border-radius: 12px; background: var(--white); color: var(--blue); box-shadow: 0 6px 16px -8px rgba(12, 31, 69, .25); }
.feature-points h4 { font-size: 16px; font-weight: 600; color: var(--ink); }
.feature-points p { font-size: 14px; color: var(--muted); }

/* 服务流程：横向时间轴 */
.timeline {
  position: relative;
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 24px;
}
.timeline::before {
  content: "";
  position: absolute;
  top: 28px;
  left: 10%;
  right: 10%;
  height: 1px;
  background: #c6d4f2;
}
.timeline li {
  position: relative;
  text-align: center;
  padding: 0 20px 32px;
  border-radius: 20px;
  transition: background .3s, box-shadow .3s;
}
.timeline li:hover { background: var(--bg); }
.timeline li:hover .node { box-shadow: 0 0 0 8px var(--bg); }
.node {
  display: grid;
  place-items: center;
  width: 56px;
  height: 56px;
  margin: 0 auto 28px;
  border-radius: 50%;
  background: var(--white);
  border: 1px solid #c6d4f2;
  box-shadow: 0 0 0 8px var(--white);
  font-size: 15px;
  font-weight: 700;
  letter-spacing: .04em;
  color: var(--blue);
  font-variant-numeric: tabular-nums;
  transition: background .25s, color .25s, border-color .25s;
}
.timeline li:hover .node { background: linear-gradient(135deg, var(--blue), #4f8bff); border-color: transparent; color: var(--white); }
.timeline h3 { font-size: 18px; font-weight: 600; color: var(--ink); }
.timeline p { margin-top: 8px; font-size: 14px; color: var(--muted); }

/* 安全可控：深色区块 */
.security {
  background:
    radial-gradient(1000px 420px at 85% 0%, rgba(31, 94, 255, .28), transparent 60%),
    var(--navy);
}
.sec-grid { display: grid; grid-template-columns: repeat(4, 1fr); border-top: 1px solid rgba(255, 255, 255, .12); }
.sec-grid li { padding: 44px 32px 8px 0; }
.sec-grid li + li { padding-left: 32px; border-left: 1px solid rgba(255, 255, 255, .08); }
.sec-icon {
  display: grid;
  place-items: center;
  width: 52px;
  height: 52px;
  border-radius: 14px;
  background: linear-gradient(135deg, rgba(47, 213, 195, .18), rgba(31, 94, 255, .18));
  border: 1px solid rgba(255, 255, 255, .1);
  color: var(--cyan);
}
.sec-grid h3 { margin-top: 24px; font-size: 19px; font-weight: 600; color: var(--white); }
.sec-grid p { margin-top: 10px; font-size: 14px; color: #93a6cc; }

/* 常见问题 */
.faq-list { max-width: 880px; border-top: 1px solid var(--line); }
.faq details { border-bottom: 1px solid var(--line); }
.faq summary {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  padding: 28px 4px;
  cursor: pointer;
  list-style: none;
}
.faq summary::-webkit-details-marker { display: none; }
.faq summary h3 { font-size: 18px; font-weight: 600; color: var(--ink); }
.faq-toggle { flex: none; display: grid; place-items: center; width: 32px; height: 32px; border-radius: 50%; border: 1px solid var(--line); color: var(--blue); transition: transform .25s, background .25s; }
.faq details[open] .faq-toggle { transform: rotate(45deg); background: var(--blue-soft); }
.faq details p { padding: 0 64px 28px 4px; color: var(--text); }

/* 关于我们 */
.about { background: var(--bg); }
.about-grid { display: grid; grid-template-columns: 1.1fr 1fr; gap: 88px; align-items: center; }
.about-photo { width: 100%; aspect-ratio: 5 / 4; object-fit: cover; border-radius: 24px; }
.about-text h2 { margin: 18px 0 28px; font-size: clamp(28px, 3vw, 40px); line-height: 1.3; font-weight: 700; color: var(--ink); letter-spacing: .02em; }
.about-text p { font-size: 16px; line-height: 2; color: var(--text); }
.about-text p + p { margin-top: 16px; }
.link-arrow { display: inline-flex; align-items: center; gap: 8px; margin-top: 36px; font-weight: 600; color: var(--blue); }
.link-arrow .i { transition: transform .25s; }
.link-arrow:hover .i { transform: translateX(4px); }

/* 联系我们 */
.contact { padding-top: 112px; padding-bottom: 112px; }
.contact-card {
  position: relative;
  display: flex;
  gap: 56px;
  align-items: center;
  justify-content: space-between;
  padding: 72px;
  border-radius: 28px;
  overflow: hidden;
  background:
    radial-gradient(700px 360px at 100% 0%, rgba(47, 213, 195, .22), transparent 60%),
    radial-gradient(800px 420px at 0% 100%, rgba(31, 94, 255, .45), transparent 60%),
    var(--navy);
  color: var(--white);
}
.contact-card .eyebrow { color: var(--cyan); }
.contact-main { flex: 1; min-width: 0; }
.contact-main h2 { margin-top: 18px; font-size: clamp(28px, 3vw, 40px); line-height: 1.3; font-weight: 700; letter-spacing: .02em; }
.contact-sub { margin-top: 14px; color: #a9bbdf; }
.contact-list { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 28px 32px; margin-top: 44px; padding-top: 36px; border-top: 1px solid rgba(255, 255, 255, .12); }
.contact-list li { display: flex; gap: 12px; align-items: flex-start; min-width: 0; }
.c-icon { flex: none; display: grid; place-items: center; width: 36px; height: 36px; border-radius: 10px; background: rgba(255, 255, 255, .08); color: var(--cyan); }
.c-label { display: block; font-size: 13px; color: #8ea2c8; }
.contact-list a, .contact-list strong { font-size: 16px; font-weight: 600; overflow-wrap: anywhere; }
.contact-list a:hover { text-decoration: underline; }
.contact-cta:empty { display: none; }
.contact-cta { display: flex; flex-wrap: wrap; gap: 14px; margin-top: 44px; }
.qr { flex: none; margin: 0; padding: 16px; border-radius: 16px; background: var(--white); text-align: center; color: var(--ink); }
.qr img { width: 148px; height: 148px; object-fit: contain; }
.qr figcaption { margin-top: 8px; font-size: 13px; }

/* 页脚 */
.footer { position: relative; background: #050f24; color: #8395b9; font-size: 14px; }
.footer::before {
  content: "";
  position: absolute;
  inset: 0 0 auto;
  height: 1px;
  background: linear-gradient(90deg, transparent, rgba(47, 213, 195, .5), rgba(31, 94, 255, .5), transparent);
}
.footer-inner {
  max-width: var(--wrap);
  margin: 0 auto;
  padding: 72px 0 48px;
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1.4fr;
  gap: 48px;
}
.footer .brand-name { color: var(--white); }
.footer-brand p { margin-top: 20px; max-width: 380px; line-height: 1.9; }
.footer-col h2 { margin-bottom: 18px; font-size: 15px; font-weight: 600; color: var(--white); }
.footer-col a, .footer-col li { display: block; margin-top: 10px; }
.footer-col a:hover { color: var(--white); }
.footer-bottom {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 8px 28px;
  padding: 24px 56px;
  border-top: 1px solid rgba(255, 255, 255, .06);
  font-size: 13px;
}
.footer-bottom a:hover { color: var(--white); }

/* 右侧悬浮咨询栏 */
.float-bar {
  position: fixed;
  right: 20px;
  bottom: 32px;
  z-index: 45;
  display: grid;
  gap: 8px;
}
.float-item {
  position: relative;
  display: grid;
  justify-items: center;
  align-content: center;
  gap: 2px;
  width: 64px;
  height: 64px;
  border-radius: 16px;
  background: var(--white);
  border: 1px solid var(--line);
  box-shadow: 0 10px 30px -12px rgba(12, 31, 69, .3);
  font-size: 12px;
  color: var(--text);
  cursor: pointer;
  transition: color .2s, border-color .2s;
}
.float-item:hover, .float-item:focus-within { color: var(--blue); border-color: #c6d4f2; }
.float-pop {
  position: absolute;
  right: calc(100% + 12px);
  top: 50%;
  transform: translateY(-50%);
  display: none;
  padding: 12px 18px;
  border-radius: 12px;
  background: var(--white);
  box-shadow: var(--shadow);
  border: 1px solid var(--line);
  font-style: normal;
  font-size: 17px;
  font-weight: 700;
  color: var(--ink);
  white-space: nowrap;
  font-variant-numeric: tabular-nums;
}
.qr-pop { text-align: center; font-size: 13px; font-weight: 400; color: var(--muted); }
.qr-pop img { width: 132px; height: 132px; margin-bottom: 6px; object-fit: contain; }
.float-item:hover .float-pop, .float-item:focus .float-pop, .float-item:focus-within .float-pop { display: block; }
.float-item.to-top { display: none; }
.float-item.to-top.show { display: grid; }

/* 滚动渐显（仅一次） */
@media (prefers-reduced-motion: no-preference) {
  .reveal { opacity: 0; transform: translateY(28px); transition: opacity .8s ease, transform .8s ease; }
  .reveal.in { opacity: 1; transform: none; }
}

/* 关闭状态页 */
.closed { display: grid; place-items: center; min-height: 100vh; background: var(--bg); }
.closed-main { text-align: center; }
.closed-main h1 { font-size: 28px; color: var(--ink); }
.closed-main p { margin: 12px 0 24px; color: var(--muted); }

/* 响应式 */
@media (max-width: 1199px) {
  .hero-visual { display: none; }
}
@media (max-width: 1279px) {
  .section { padding: 112px 40px; }
  .hero-inner { padding: 80px 40px 180px; }
  .hero-stats { width: calc(100% - 80px); }
  .footer-inner { padding: 64px 40px 40px; }
}
@media (min-width: 1101px) and (max-width: 1240px) {
  /* 汉堡菜单出现前，顶栏要同时放下全部导航和两个按钮。 */
  .topbar-inner { padding: 0 24px; gap: 16px; }
  .topnav { gap: 0; }
}
@media (max-width: 1100px) {
  .topbar-inner { gap: 16px; }
  .top-actions { margin-left: auto; }
  .menu-btn { display: grid; place-items: center; }
  .topnav {
    position: fixed;
    top: var(--top);
    left: 0;
    right: 0;
    display: none;
    flex-direction: column;
    padding: 8px 16px 16px;
    background: var(--white);
    border-bottom: 1px solid var(--line);
    box-shadow: var(--shadow);
  }
  .topnav.open { display: flex; }
  .topnav a { padding: 14px 8px; border-bottom: 1px solid var(--line); }
  .topnav a::after { display: none; }
  .topbar:not(.solid) .topnav a { color: var(--text); }
  .feature, .feature.reverse { gap: 56px; }
  .sec-grid { grid-template-columns: repeat(2, 1fr); }
  .sec-grid li:nth-child(3) { padding-left: 0; border-left: 0; }
  .contact-list { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}
@media (max-width: 640px) {
  /* 窄屏顶栏放不下两个按钮，只留登录系统；联系我们在导航菜单里。 */
  .top-contact { display: none; }
}
@media (max-width: 900px) {
  :root { --top: 60px; }
  .topbar-inner { padding: 0 16px; gap: 12px; }
  .hero { min-height: auto; }
  .hero-inner { padding: 72px 16px 40px; }
  .hero::before { background: linear-gradient(180deg, rgba(7, 20, 48, .9), rgba(7, 20, 48, .82)); }
  .hero-sub { font-size: 16px; }
  .hero-hotline { margin-left: 0; width: 100%; }
  .hero-stats { position: relative; left: auto; transform: none; width: auto; margin: 0 16px; grid-template-columns: repeat(2, 1fr); }
  .hero-stats li { padding: 20px 0; }
  .hero-stats li + li { padding-left: 0; border-left: 0; }
  .hero-stats li:nth-child(even) { padding-left: 20px; border-left: 1px solid rgba(255, 255, 255, .1); }
  .hero-stats li:nth-child(n+3) { border-top: 1px solid rgba(255, 255, 255, .1); }
  .hero-stats strong { font-size: 26px; }
  .section { padding: 80px 16px; }
  .sec-head { margin-bottom: 48px; }
  .compare { grid-template-columns: 1fr; }
  .compare-col { padding: 32px 24px; }
  .feature, .feature.reverse { grid-template-columns: 1fr; gap: 32px; }
  .feature.reverse .feature-media { order: 0; }
  .feature + .feature { margin-top: 88px; }
  .feature-no { font-size: 56px; }
  .feature-body h3 { font-size: 26px; }
  .timeline { grid-template-columns: 1fr; row-gap: 0; }
  .timeline li { display: grid; grid-template-columns: 48px 1fr; column-gap: 16px; text-align: left; padding: 0 0 28px; }
  .timeline li:not(:last-child)::after { content: ""; position: absolute; left: 24px; top: 52px; bottom: 4px; width: 1px; background: #c6d4f2; }
  .node { grid-row: span 2; width: 48px; height: 48px; margin: 0; }
  .timeline p { margin-top: 2px; }
  .sec-grid { grid-template-columns: 1fr; }
  .sec-grid li, .sec-grid li + li { padding: 28px 0; border-left: 0; border-bottom: 1px solid rgba(255, 255, 255, .08); }
  .faq details p { padding-right: 4px; }
  .about-grid { grid-template-columns: 1fr; gap: 40px; }
  .contact-card { flex-direction: column; align-items: stretch; padding: 40px 24px; border-radius: 20px; }
  .contact-list { grid-template-columns: 1fr; }
  .qr { align-self: center; }
  .footer-inner { grid-template-columns: 1fr 1fr; padding: 48px 16px 24px; gap: 32px; }
  .footer-brand { grid-column: 1 / -1; }
  .footer-bottom { padding: 16px; }
  .float-bar { right: 12px; bottom: 16px; }
  .float-item { width: 48px; height: 48px; border-radius: 14px; }
  .float-item span, .float-pop { display: none !important; }
}
@media (max-width: 560px) {
  .brand-name { font-size: 16px; }
  .hero-cta .btn { width: 100%; }
}