/* ==========================================================================
   三泰网络 santainet.com — 官网样式
   设计基调：深海军蓝 + 青绿科技光感，低碳克制、工程感强
   ========================================================================== */

:root {
  --navy-950: #040e1b;
  --navy-900: #061726;
  --navy-850: #071d33;
  --navy-800: #0a2540;
  --navy-700: #0e3357;
  --ink: #0b2033;
  --ink-soft: #27455f;
  --muted: #5b7189;
  --line: #e4ecf5;
  --line-soft: #eef4fa;
  --teal: #2fd6c4;
  --teal-deep: #0fa79f;
  --blue: #1f7ae0;
  --sky: #7fdcf0;
  --bg-soft: #f4f8fc;
  --white: #fff;
  --radius: 18px;
  --shadow-sm: 0 10px 24px -18px rgba(8, 32, 56, 0.5);
  --shadow-md: 0 28px 60px -42px rgba(8, 32, 56, 0.55);
  --ease: cubic-bezier(0.22, 0.7, 0.25, 1);
  --container: 1200px;
  --font-sans: "PingFang SC", "HarmonyOS Sans SC", "Source Han Sans SC",
    "Noto Sans SC", "Microsoft YaHei", system-ui, -apple-system, sans-serif;
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

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

body {
  margin: 0;
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.75;
  color: var(--ink);
  background: #fff;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  overflow-x: hidden;
}

img,
svg {
  max-width: 100%;
}

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

h1,
h2,
h3,
h4,
p,
ul,
ol,
dl,
dd {
  margin: 0;
}

ul {
  padding: 0;
  list-style: none;
}

button {
  font: inherit;
  color: inherit;
  border: 0;
  background: none;
  cursor: pointer;
}

::selection {
  background: rgba(47, 214, 196, 0.28);
}

:focus-visible {
  outline: 2px solid var(--teal-deep);
  outline-offset: 3px;
}

/* ---------- 布局基础 ---------- */
.container {
  width: min(var(--container), calc(100% - 48px));
  margin-inline: auto;
}

.section {
  padding: clamp(64px, 7.4vw, 116px) 0;
  position: relative;
  scroll-margin-top: 84px;
}

.section--soft {
  background: var(--bg-soft);
}

.section--dark {
  background: radial-gradient(
      1100px 620px at 78% 0%,
      rgba(31, 122, 224, 0.22),
      transparent 66%
    ),
    radial-gradient(900px 600px at 4% 96%, rgba(47, 214, 196, 0.12), transparent 70%),
    linear-gradient(180deg, #061627 0%, #071c30 55%, #05131f 100%);
  color: #dbe9f6;
}

.skip-link {
  position: absolute;
  left: 16px;
  top: -60px;
  z-index: 200;
  padding: 10px 18px;
  border-radius: 8px;
  background: #fff;
  color: var(--ink);
  box-shadow: var(--shadow-sm);
  transition: top 0.2s var(--ease);
}

.skip-link:focus {
  top: 12px;
}

/* ---------- 通用文字 ---------- */
.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: #0a7d7b;
}

.eyebrow::before {
  content: "";
  width: 26px;
  height: 2px;
  border-radius: 2px;
  background: linear-gradient(90deg, var(--teal), var(--blue));
}

.section--dark .eyebrow {
  color: var(--teal);
}

.h2 {
  font-size: clamp(26px, 3vw, 42px);
  line-height: 1.28;
  font-weight: 700;
  letter-spacing: -0.015em;
  color: var(--ink);
  margin-top: 18px;
}

.section--dark .h2 {
  color: #fff;
}

.lead {
  margin-top: 16px;
  font-size: 16px;
  line-height: 1.95;
  color: var(--muted);
  max-width: 58ch;
}

.section--dark .lead {
  color: #a6c2d8;
}

.section-head {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: 40px;
  flex-wrap: wrap;
}

.section-head__aside {
  max-width: 380px;
  font-size: 14.5px;
  line-height: 1.9;
  color: var(--muted);
  padding-bottom: 6px;
}

/* ---------- 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  height: 50px;
  padding: 0 26px;
  border-radius: 10px;
  font-size: 15px;
  font-weight: 600;
  letter-spacing: 0.02em;
  transition: transform 0.3s var(--ease), box-shadow 0.3s var(--ease),
    background 0.3s var(--ease), border-color 0.3s var(--ease);
}

.btn svg {
  width: 16px;
  height: 16px;
  transition: transform 0.3s var(--ease);
}

.btn:hover svg {
  transform: translateX(3px);
}

.btn--primary {
  background: linear-gradient(135deg, #45e3d2 0%, #17bccb 100%);
  color: #04222e;
  box-shadow: 0 16px 34px -16px rgba(45, 220, 205, 0.7),
    inset 0 1px 0 rgba(255, 255, 255, 0.45);
}

.btn--primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 22px 40px -16px rgba(45, 220, 205, 0.85),
    inset 0 1px 0 rgba(255, 255, 255, 0.55);
}

.btn--ghost {
  border: 1px solid rgba(150, 200, 235, 0.34);
  color: #e4eff8;
  background: rgba(255, 255, 255, 0.045);
}

.btn--ghost:hover {
  border-color: rgba(47, 214, 196, 0.7);
  background: rgba(47, 214, 196, 0.12);
  transform: translateY(-2px);
}

/* ---------- 页头 ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 80;
  background: rgba(255, 255, 255, 0.88);
  backdrop-filter: saturate(180%) blur(16px);
  -webkit-backdrop-filter: saturate(180%) blur(16px);
  border-bottom: 1px solid rgba(11, 32, 51, 0.07);
  transition: box-shadow 0.3s var(--ease), background 0.3s var(--ease);
}

.site-header.is-scrolled {
  background: rgba(255, 255, 255, 0.96);
  box-shadow: 0 16px 40px -32px rgba(8, 28, 52, 0.7);
}

.header__inner {
  height: 74px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 28px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 11px;
  flex-shrink: 0;
}

.brand__mark {
  width: 40px;
  height: auto;
  display: block;
}

.brand__name {
  font-size: 20px;
  font-weight: 700;
  letter-spacing: 0.06em;
  color: #0b2647;
  line-height: 1;
}

.brand__en {
  display: block;
  margin-top: 4px;
  font-size: 9px;
  letter-spacing: 0.18em;
  color: #7b93a8;
  font-weight: 500;
}

.nav {
  display: flex;
  align-items: center;
  gap: 4px;
}

.nav a {
  position: relative;
  padding: 9px 15px;
  border-radius: 8px;
  font-size: 14.5px;
  color: #294a63;
  transition: color 0.2s var(--ease), background 0.2s var(--ease);
}

.nav a:hover {
  color: #0a7f8c;
  background: #f1f8fb;
}

.nav a.is-active {
  color: #068b93;
  font-weight: 600;
}

.nav__cta {
  display: none;
}

.nav a.is-active::after {
  content: "";
  position: absolute;
  left: 50%;
  bottom: 1px;
  width: 18px;
  height: 2px;
  border-radius: 2px;
  transform: translateX(-50%);
  background: linear-gradient(90deg, var(--teal), var(--blue));
}

.header__cta {
  height: 40px;
  padding: 0 18px;
  border-radius: 8px;
  font-size: 14px;
  font-weight: 600;
  color: #053040;
  background: linear-gradient(135deg, #4ae5d3, #20c3cd);
  box-shadow: 0 10px 22px -14px rgba(32, 195, 205, 0.9);
  display: inline-flex;
  align-items: center;
  gap: 8px;
  transition: transform 0.25s var(--ease), box-shadow 0.25s var(--ease);
}

.header__cta:hover {
  transform: translateY(-1px);
  box-shadow: 0 16px 26px -14px rgba(32, 195, 205, 0.95);
}

.nav-toggle {
  display: none;
  width: 44px;
  height: 44px;
  border-radius: 10px;
  border: 1px solid var(--line);
  align-items: center;
  justify-content: center;
  flex-direction: column;
  gap: 5px;
}

.nav-toggle span {
  display: block;
  width: 18px;
  height: 2px;
  border-radius: 2px;
  background: #1c3d57;
  transition: transform 0.28s var(--ease), opacity 0.2s var(--ease);
}

.nav-toggle[aria-expanded="true"] span:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}

.nav-toggle[aria-expanded="true"] span:nth-child(2) {
  opacity: 0;
}

.nav-toggle[aria-expanded="true"] span:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

/* ---------- 首屏 ---------- */
.hero {
  position: relative;
  overflow: hidden;
  color: #e6f1fb;
  background: radial-gradient(
      980px 560px at 78% 10%,
      rgba(31, 130, 224, 0.3),
      transparent 62%
    ),
    radial-gradient(760px 520px at 6% 92%, rgba(47, 214, 196, 0.16), transparent 70%),
    linear-gradient(178deg, #061626 0%, #08203a 48%, #071a2d 100%);
}

.hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image: linear-gradient(rgba(124, 190, 245, 0.07) 1px, transparent 1px),
    linear-gradient(90deg, rgba(124, 190, 245, 0.07) 1px, transparent 1px);
  background-size: 68px 68px;
  mask-image: radial-gradient(120% 90% at 60% 30%, #000 25%, transparent 78%);
  -webkit-mask-image: radial-gradient(120% 90% at 60% 30%, #000 25%, transparent 78%);
  pointer-events: none;
}

.hero::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: -1px;
  height: 120px;
  background: linear-gradient(180deg, transparent, rgba(4, 14, 27, 0.55));
  pointer-events: none;
}

.hero__inner {
  position: relative;
  z-index: 2;
  display: grid;
  grid-template-columns: minmax(0, 1.02fr) minmax(0, 1.1fr);
  gap: clamp(32px, 5vw, 64px);
  align-items: center;
  padding: clamp(52px, 6.4vw, 92px) 0 clamp(64px, 7vw, 104px);
}

.hero__badge {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 7px 14px 7px 8px;
  border-radius: 999px;
  border: 1px solid rgba(120, 200, 235, 0.26);
  background: rgba(18, 70, 110, 0.35);
  font-size: 12.5px;
  letter-spacing: 0.08em;
  color: #a9d8ea;
}

.hero__badge b {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 3px 9px;
  border-radius: 999px;
  background: linear-gradient(135deg, #39ddca, #1a9fd8);
  color: #032230;
  font-size: 11.5px;
  font-weight: 700;
  letter-spacing: 0.06em;
}

.hero h1 {
  margin: 26px 0 0;
  font-size: clamp(34px, 4.5vw, 62px);
  line-height: 1.16;
  font-weight: 700;
  letter-spacing: -0.02em;
  color: #fff;
}

.hero h1 .grad {
  background: linear-gradient(96deg, #ffffff 8%, #a9f0e6 52%, #58c2f4 96%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.hero__lead {
  margin-top: 22px;
  max-width: 33em;
  font-size: clamp(15px, 1.25vw, 17px);
  line-height: 1.95;
  color: #a9c5da;
}

.hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  margin-top: 34px;
}

.hero__meta {
  display: flex;
  flex-wrap: wrap;
  gap: 10px 26px;
  margin-top: 34px;
  padding-top: 24px;
  border-top: 1px solid rgba(130, 190, 235, 0.15);
  font-size: 13px;
  color: #90b1c9;
}

.hero__meta li {
  display: inline-flex;
  align-items: center;
  gap: 8px;
}

.hero__meta li::before {
  content: "";
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: var(--teal);
  box-shadow: 0 0 10px rgba(47, 214, 196, 0.9);
}

/* 首屏右侧视觉 */
.hero__visual {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 156px;
  gap: 14px;
  align-items: center;
}

.stage {
  position: relative;
  isolation: isolate;
}

.stage__glow {
  position: absolute;
  inset: 8% 6% 16%;
  border-radius: 50%;
  background: radial-gradient(
    circle at 50% 45%,
    rgba(58, 208, 244, 0.32),
    rgba(24, 108, 190, 0.12) 46%,
    transparent 70%
  );
  filter: blur(18px);
  z-index: -1;
}

.stage svg {
  display: block;
  width: 100%;
  height: auto;
  overflow: visible;
}

.rail {
  display: flex;
  flex-direction: column;
  gap: 9px;
}

.rail__card {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 11px 12px;
  border-radius: 11px;
  border: 1px solid rgba(118, 195, 235, 0.2);
  background: linear-gradient(
    150deg,
    rgba(24, 78, 120, 0.55),
    rgba(10, 38, 62, 0.55)
  );
  backdrop-filter: blur(6px);
  transition: transform 0.3s var(--ease), border-color 0.3s var(--ease),
    background 0.3s var(--ease);
}

.rail__card:hover {
  transform: translateX(-4px);
  border-color: rgba(64, 226, 210, 0.55);
  background: linear-gradient(
    150deg,
    rgba(26, 96, 132, 0.7),
    rgba(10, 44, 70, 0.65)
  );
}

.rail__icon {
  flex: 0 0 30px;
  width: 30px;
  height: 30px;
  display: grid;
  place-items: center;
  border-radius: 8px;
  background: rgba(47, 214, 196, 0.13);
  border: 1px solid rgba(47, 214, 196, 0.26);
  color: #6ff0e2;
}

.rail__icon svg {
  width: 16px;
  height: 16px;
}

.rail__text {
  font-size: 12.5px;
  line-height: 1.45;
  color: #d3e8f5;
  letter-spacing: 0.01em;
}

.rail__text small {
  display: block;
  font-size: 10.5px;
  color: #7fa6c0;
  letter-spacing: 0.12em;
  margin-top: 2px;
}

/* ---------- 覆盖区域面板 ---------- */
.coverage {
  position: relative;
  overflow: hidden;
  border-radius: 26px;
  padding: clamp(28px, 4vw, 52px);
  color: #dceaf7;
  background: radial-gradient(
      760px 420px at 82% 18%,
      rgba(32, 132, 214, 0.28),
      transparent 66%
    ),
    radial-gradient(620px 420px at 12% 90%, rgba(47, 214, 196, 0.14), transparent 70%),
    linear-gradient(155deg, #071b2e 0%, #0a2743 58%, #081d33 100%);
  box-shadow: 0 50px 100px -70px rgba(5, 24, 44, 0.9);
}

.coverage::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image: linear-gradient(rgba(120, 190, 245, 0.06) 1px, transparent 1px),
    linear-gradient(90deg, rgba(120, 190, 245, 0.06) 1px, transparent 1px);
  background-size: 56px 56px;
  mask-image: radial-gradient(100% 80% at 50% 50%, #000, transparent 85%);
  -webkit-mask-image: radial-gradient(100% 80% at 50% 50%, #000, transparent 85%);
  pointer-events: none;
}

.coverage__grid {
  position: relative;
  z-index: 2;
  display: grid;
  grid-template-columns: minmax(0, 0.74fr) minmax(0, 1.26fr);
  gap: clamp(24px, 3.6vw, 44px);
  align-items: center;
}

.coverage h2 {
  font-size: clamp(26px, 2.9vw, 40px);
  line-height: 1.3;
  letter-spacing: -0.015em;
  color: #fff;
  font-weight: 700;
}

.coverage h2 em {
  font-style: normal;
  color: var(--teal);
}

.coverage p {
  margin-top: 18px;
  font-size: 15px;
  line-height: 1.95;
  color: #a4c2d8;
}

.coverage__stats {
  display: flex;
  gap: 40px;
  margin-top: 30px;
}

.coverage__stat b {
  display: block;
  font-size: 34px;
  line-height: 1;
  font-weight: 700;
  color: #fff;
  letter-spacing: -0.02em;
}

.coverage__stat b i {
  font-style: normal;
  font-size: 15px;
  font-weight: 600;
  color: var(--teal);
  margin-left: 2px;
}

.coverage__stat span {
  display: block;
  margin-top: 8px;
  font-size: 12.5px;
  color: #82a6bf;
  letter-spacing: 0.08em;
}

.chips {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 26px;
}

.chip {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  padding: 6px 13px;
  border-radius: 999px;
  border: 1px solid rgba(120, 205, 235, 0.26);
  background: rgba(30, 118, 168, 0.16);
  font-size: 13px;
  color: #cbe8f7;
  letter-spacing: 0.04em;
}

.chip::before {
  content: "";
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: var(--teal);
  box-shadow: 0 0 8px rgba(47, 214, 196, 0.95);
}

.coverage__map {
  position: relative;
}

.coverage__map::before {
  content: "";
  position: absolute;
  inset: 6% 4%;
  border-radius: 50%;
  background: radial-gradient(circle at 50% 55%, rgba(45, 190, 220, 0.18), transparent 68%);
  filter: blur(26px);
  pointer-events: none;
}

.coverage__map picture {
  display: block;
}

.coverage__map img {
  display: block;
  width: 100%;
  height: auto;
  filter: drop-shadow(0 30px 50px rgba(0, 8, 18, 0.55));
}

/* ---------- 公司介绍 ---------- */
.about__top {
  display: grid;
  grid-template-columns: minmax(0, 0.94fr) minmax(0, 1.06fr);
  gap: clamp(32px, 5vw, 72px);
  align-items: start;
}

.about__top .h2 {
  max-width: none;
}

.about__badge {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  margin-top: 26px;
  padding: 10px 16px;
  border-radius: 12px;
  border: 1px solid rgba(15, 167, 159, 0.24);
  background: linear-gradient(120deg, rgba(47, 214, 196, 0.1), rgba(31, 122, 224, 0.07));
  font-size: 13px;
  color: #0e6b74;
  font-weight: 600;
}

.about__badge svg {
  width: 16px;
  height: 16px;
  color: var(--teal-deep);
}

.about__copy p {
  font-size: 15.5px;
  line-height: 2.05;
  color: #3c5772;
}

.about__copy p + p {
  margin-top: 18px;
}

.about__dirs {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 20px;
  margin-top: clamp(40px, 4.6vw, 60px);
}

.dir-card {
  position: relative;
  padding: 26px 24px;
  border-radius: 16px;
  border: 1px solid var(--line);
  background: linear-gradient(180deg, #ffffff, #fbfdff);
  box-shadow: var(--shadow-sm);
  transition: transform 0.35s var(--ease), box-shadow 0.35s var(--ease),
    border-color 0.35s var(--ease);
  overflow: hidden;
}

.dir-card::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  width: 100%;
  height: 100%;
  background: radial-gradient(220px 140px at 100% 0%, rgba(47, 214, 196, 0.12), transparent 70%);
  opacity: 0;
  transition: opacity 0.35s var(--ease);
  pointer-events: none;
}

.dir-card:hover {
  transform: translateY(-5px);
  border-color: #c9e8ee;
  box-shadow: 0 34px 60px -46px rgba(9, 48, 78, 0.75);
}

.dir-card:hover::before {
  opacity: 1;
}

.direction__icon {
  width: 46px;
  height: 46px;
  display: grid;
  place-items: center;
  border-radius: 13px;
  color: #0d8f96;
  background: linear-gradient(140deg, #e9fbf8, #e9f2fd);
  border: 1px solid #d9eef6;
}

.direction__icon svg {
  width: 21px;
  height: 21px;
}

.dir-card h3 {
  margin-top: 16px;
  font-size: 17px;
  font-weight: 700;
  color: var(--ink);
  letter-spacing: 0.01em;
}

.dir-card p {
  margin-top: 8px;
  font-size: 14px;
  line-height: 1.9;
  color: var(--muted);
}

/* 数据条 */
.stats {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 1px;
  margin-top: clamp(48px, 5vw, 72px);
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: 16px;
  overflow: hidden;
}

.stat {
  background: #fff;
  padding: 26px 24px;
}

.stat b {
  display: flex;
  align-items: baseline;
  gap: 4px;
  font-size: clamp(28px, 3vw, 38px);
  line-height: 1.1;
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--ink);
}

.stat b i {
  font-style: normal;
  font-size: 14px;
  font-weight: 600;
  color: var(--teal-deep);
}

.stat span {
  display: block;
  margin-top: 8px;
  font-size: 13px;
  color: var(--muted);
  letter-spacing: 0.04em;
}

/* ---------- 1+4 架构 ---------- */
.arch {
  margin-top: 44px;
  display: flex;
  flex-direction: column;
  align-items: center;
}

.arch__bases {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 12px;
}

.arch__pill {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 12px 20px;
  border-radius: 12px;
  background: #fff;
  border: 1px solid #dcebf5;
  box-shadow: var(--shadow-sm);
  font-size: 14.5px;
  font-weight: 600;
  color: #123a58;
}

.arch__pill svg {
  width: 18px;
  height: 18px;
  color: var(--teal-deep);
}

.arch__connector {
  width: 2px;
  height: 34px;
  margin: 6px 0;
  background: linear-gradient(
    180deg,
    rgba(15, 167, 159, 0.1),
    rgba(15, 167, 159, 0.65),
    rgba(31, 122, 224, 0.1)
  );
  position: relative;
}

.arch__connector::after {
  content: "";
  position: absolute;
  left: 50%;
  bottom: -1px;
  width: 7px;
  height: 7px;
  border-right: 2px solid rgba(31, 122, 224, 0.7);
  border-bottom: 2px solid rgba(31, 122, 224, 0.7);
  transform: translate(-50%, 0) rotate(45deg);
}

.arch__main {
  position: relative;
  display: flex;
  align-items: center;
  gap: 20px;
  width: min(620px, 100%);
  padding: 22px 28px;
  border-radius: 16px;
  color: #eaf6ff;
  background: radial-gradient(
      300px 120px at 88% 20%,
      rgba(47, 214, 196, 0.28),
      transparent 70%
    ),
    linear-gradient(120deg, #0a2742, #0d3d63 60%, #0b2c4b);
  box-shadow: 0 30px 60px -40px rgba(9, 38, 66, 0.9);
  overflow: hidden;
}

.arch__main::after {
  content: "";
  position: absolute;
  inset: 0;
  background-image: linear-gradient(rgba(140, 210, 245, 0.07) 1px, transparent 1px),
    linear-gradient(90deg, rgba(140, 210, 245, 0.07) 1px, transparent 1px);
  background-size: 32px 32px;
  mask-image: linear-gradient(90deg, transparent, #000);
  -webkit-mask-image: linear-gradient(90deg, transparent, #000);
}

.arch__num {
  flex: 0 0 auto;
  width: 52px;
  height: 52px;
  display: grid;
  place-items: center;
  border-radius: 14px;
  font-size: 24px;
  font-weight: 700;
  color: #04222e;
  background: linear-gradient(135deg, #4ae5d3, #24bfd0);
  box-shadow: 0 12px 26px -14px rgba(45, 220, 205, 0.9);
}

.arch__main h3 {
  font-size: 19px;
  font-weight: 700;
  letter-spacing: 0.02em;
}

.arch__main p {
  margin-top: 4px;
  font-size: 13px;
  color: #a9c9de;
  line-height: 1.7;
}

.arch__four {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 16px;
  width: 100%;
  margin-top: 18px;
}

.carrier {
  position: relative;
  padding: 26px 22px 24px;
  border-radius: 16px;
  background: #fff;
  border: 1px solid #e2ecf6;
  box-shadow: var(--shadow-sm);
  transition: transform 0.35s var(--ease), box-shadow 0.35s var(--ease),
    border-color 0.35s var(--ease);
  overflow: hidden;
}

.carrier::before {
  content: "";
  position: absolute;
  inset: 0 0 auto;
  height: 3px;
  background: linear-gradient(90deg, var(--teal), var(--blue));
  opacity: 0;
  transition: opacity 0.35s var(--ease);
}

.carrier:hover {
  transform: translateY(-6px);
  border-color: #c9e8ee;
  box-shadow: 0 34px 60px -44px rgba(9, 48, 78, 0.7);
}

.carrier:hover::before {
  opacity: 1;
}

.carrier__top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 18px;
}

.carrier__icon {
  width: 42px;
  height: 42px;
  display: grid;
  place-items: center;
  border-radius: 12px;
  color: #0e8f96;
  background: linear-gradient(140deg, #eafaf7, #eaf2fd);
  border: 1px solid #ddeef7;
}

.carrier__icon svg {
  width: 20px;
  height: 20px;
}

.carrier__no {
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.12em;
  color: #b6cadd;
}

.carrier h3 {
  font-size: 16px;
  line-height: 1.55;
  font-weight: 700;
  color: var(--ink);
}

.carrier p {
  margin-top: 10px;
  font-size: 13.5px;
  line-height: 1.85;
  color: var(--muted);
}

/* ---------- 双底座 ---------- */
.bases__grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 22px;
  margin-top: 48px;
}

.base-card {
  position: relative;
  padding: clamp(26px, 3vw, 38px);
  border-radius: 20px;
  border: 1px solid rgba(116, 190, 232, 0.18);
  background: linear-gradient(
    158deg,
    rgba(22, 66, 100, 0.42),
    rgba(8, 30, 50, 0.55) 72%
  );
  overflow: hidden;
  transition: border-color 0.35s var(--ease), transform 0.35s var(--ease);
}

.base-card::before {
  content: "";
  position: absolute;
  top: -40%;
  right: -20%;
  width: 320px;
  height: 320px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(47, 214, 196, 0.18), transparent 65%);
  pointer-events: none;
}

.base-card:hover {
  border-color: rgba(63, 222, 208, 0.45);
  transform: translateY(-4px);
}

.base-card__head {
  display: flex;
  align-items: center;
  gap: 16px;
}

.base-card__icon {
  width: 52px;
  height: 52px;
  flex: 0 0 52px;
  display: grid;
  place-items: center;
  border-radius: 14px;
  color: #06202f;
  background: linear-gradient(135deg, #4ae5d3, #24a9dd);
  box-shadow: 0 14px 30px -18px rgba(47, 214, 196, 0.9);
}

.base-card__icon svg {
  width: 24px;
  height: 24px;
}

.base-card__kicker {
  font-size: 11px;
  letter-spacing: 0.2em;
  color: #7fb6cf;
  text-transform: uppercase;
}

.base-card h3 {
  margin-top: 4px;
  font-size: clamp(19px, 1.8vw, 23px);
  font-weight: 700;
  color: #fff;
  letter-spacing: 0.01em;
}

.base-card__desc {
  margin-top: 18px;
  font-size: 14.5px;
  line-height: 1.95;
  color: #a6c3d8;
}

.base-list {
  margin-top: 22px;
  display: grid;
  gap: 12px;
}

.base-list li {
  display: grid;
  grid-template-columns: 18px minmax(0, 1fr);
  gap: 10px;
  font-size: 14px;
  line-height: 1.75;
  color: #cfe3f1;
}

.base-list svg {
  width: 16px;
  height: 16px;
  margin-top: 5px;
  color: var(--teal);
}

.base-list b {
  font-weight: 600;
  color: #fff;
}

.tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 24px;
  padding-top: 20px;
  border-top: 1px solid rgba(120, 180, 220, 0.14);
}

.tag {
  padding: 5px 11px;
  border-radius: 6px;
  font-size: 12px;
  color: #8fd8e3;
  background: rgba(47, 214, 196, 0.08);
  border: 1px solid rgba(47, 214, 196, 0.18);
  letter-spacing: 0.04em;
}

/* ---------- 业务场景 ---------- */
.scene-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 20px;
  margin-top: 48px;
}

.scene {
  position: relative;
  padding: 30px 26px 28px;
  border-radius: 18px;
  background: #fff;
  border: 1px solid var(--line);
  box-shadow: var(--shadow-sm);
  transition: transform 0.35s var(--ease), box-shadow 0.35s var(--ease);
  overflow: hidden;
}

.scene::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 2px;
  background: linear-gradient(90deg, var(--teal), var(--blue));
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.45s var(--ease);
}

.scene:hover {
  transform: translateY(-6px);
  box-shadow: 0 40px 70px -52px rgba(9, 48, 78, 0.8);
}

.scene:hover::after {
  transform: scaleX(1);
}

.scene__head {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.scene__icon {
  width: 46px;
  height: 46px;
  display: grid;
  place-items: center;
  border-radius: 13px;
  color: #0c8f97;
  background: linear-gradient(145deg, #e9fbf8, #eaf2fd);
  border: 1px solid #dbeef7;
}

.scene__icon svg {
  width: 22px;
  height: 22px;
}

.scene__no {
  font-size: 12px;
  letter-spacing: 0.16em;
  font-weight: 700;
  color: #bed0e0;
}

.scene h3 {
  margin-top: 20px;
  font-size: 19px;
  font-weight: 700;
  color: var(--ink);
}

.scene__sub {
  margin-top: 6px;
  font-size: 13.5px;
  color: #0a767c;
  font-weight: 600;
}

.scene ul {
  margin-top: 20px;
  padding-top: 18px;
  border-top: 1px dashed var(--line);
  display: grid;
  gap: 10px;
}

.scene li {
  position: relative;
  padding-left: 16px;
  font-size: 13.5px;
  line-height: 1.8;
  color: #4a6580;
}

.scene li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 11px;
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: #a8dbe0;
}

/* ---------- 联系 ---------- */
.contact-card {
  position: relative;
  overflow: hidden;
  border-radius: 26px;
  padding: clamp(30px, 4.4vw, 58px);
  color: #e8f3fb;
  background: radial-gradient(
      700px 380px at 88% 8%,
      rgba(47, 214, 196, 0.22),
      transparent 62%
    ),
    radial-gradient(680px 420px at 4% 96%, rgba(31, 122, 224, 0.24), transparent 66%),
    linear-gradient(140deg, #06182a, #0a2a47 58%, #082035);
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 0.92fr);
  gap: clamp(30px, 4vw, 56px);
  align-items: center;
}

.contact-card::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image: linear-gradient(rgba(125, 190, 240, 0.055) 1px, transparent 1px),
    linear-gradient(90deg, rgba(125, 190, 240, 0.055) 1px, transparent 1px);
  background-size: 48px 48px;
  mask-image: radial-gradient(90% 90% at 30% 40%, #000, transparent 80%);
  -webkit-mask-image: radial-gradient(90% 90% at 30% 40%, #000, transparent 80%);
  pointer-events: none;
}

.contact-card > * {
  position: relative;
  z-index: 2;
}

.contact-card h2 {
  font-size: clamp(26px, 3vw, 40px);
  line-height: 1.3;
  color: #fff;
  letter-spacing: -0.015em;
  font-weight: 700;
}

.contact-card__lead {
  margin-top: 16px;
  font-size: 15px;
  line-height: 1.95;
  color: #a7c3d8;
  max-width: 34ch;
}

.contact-list {
  margin-top: 30px;
  display: grid;
  gap: 16px;
}

.contact-list div {
  display: grid;
  grid-template-columns: 84px minmax(0, 1fr);
  gap: 14px;
  align-items: baseline;
}

.contact-list dt {
  font-size: 12.5px;
  color: #7ea6c0;
  letter-spacing: 0.1em;
}

.contact-list dd {
  font-size: 14.5px;
  color: #e2f0fa;
}

.contact-list a {
  border-bottom: 1px solid rgba(90, 220, 230, 0.35);
  transition: color 0.2s var(--ease), border-color 0.2s var(--ease);
}

.contact-list a:hover {
  color: #7ff3e6;
  border-color: #7ff3e6;
}

.contact-form {
  padding: 26px;
  border-radius: 18px;
  border: 1px solid rgba(120, 195, 235, 0.2);
  background: rgba(10, 38, 60, 0.55);
  backdrop-filter: blur(8px);
}

.contact-form h3 {
  font-size: 15px;
  font-weight: 600;
  color: #dceaf6;
  letter-spacing: 0.04em;
}

.form-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
  margin-top: 16px;
}

.field {
  display: block;
}

.field--full {
  grid-column: 1 / -1;
}

.field span {
  display: block;
  font-size: 11.5px;
  letter-spacing: 0.1em;
  color: #7ea6c0;
  margin-bottom: 6px;
}

.field input,
.field select,
.field textarea {
  width: 100%;
  padding: 10px 12px;
  border-radius: 8px;
  border: 1px solid rgba(125, 190, 230, 0.22);
  background: rgba(4, 20, 34, 0.55);
  color: #eaf5fc;
  font: inherit;
  font-size: 13.5px;
  transition: border-color 0.2s var(--ease), background 0.2s var(--ease);
}

.field input::placeholder,
.field textarea::placeholder {
  color: #66879e;
}

.field input:focus,
.field select:focus,
.field textarea:focus {
  outline: none;
  border-color: rgba(47, 214, 196, 0.7);
  background: rgba(6, 28, 46, 0.8);
}

.field textarea {
  resize: vertical;
  min-height: 84px;
}

.contact-form .btn {
  width: 100%;
  margin-top: 14px;
  height: 46px;
}

.form-note {
  margin-top: 10px;
  font-size: 11.5px;
  color: #6f92aa;
  line-height: 1.7;
}

/* ---------- 页脚 ---------- */
.site-footer {
  background: linear-gradient(180deg, #051320, #040e19);
  color: #93b0c6;
  padding: clamp(48px, 6vw, 72px) 0 0;
}

.footer__grid {
  display: grid;
  grid-template-columns: minmax(0, 1.5fr) repeat(3, minmax(0, 0.8fr));
  gap: 40px;
  padding-bottom: 44px;
}

.footer__brand .brand__name {
  color: #fff;
}

.footer__brand .brand__en {
  color: #6f92aa;
}

.footer__brand p {
  margin-top: 18px;
  font-size: 13.5px;
  line-height: 1.9;
  color: #7b9cb4;
  max-width: 32ch;
}

.footer__col h4 {
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.12em;
  color: #d6e6f2;
  margin-bottom: 16px;
}

.footer__col li + li {
  margin-top: 10px;
}

.footer__col a,
.footer__col span {
  font-size: 13.5px;
  color: #8aa8bf;
  transition: color 0.2s var(--ease);
}

.footer__col a:hover {
  color: #63e6d8;
}

.footer__bottom {
  border-top: 1px solid rgba(130, 180, 215, 0.12);
  padding: 20px 0 26px;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 10px 24px;
  font-size: 12.5px;
  color: #6b8ba2;
}

.footer__bottom a {
  transition: color 0.2s var(--ease);
}

.footer__bottom a:hover {
  color: #63e6d8;
}

.to-top {
  position: fixed;
  right: 22px;
  bottom: 24px;
  z-index: 70;
  width: 44px;
  height: 44px;
  display: grid;
  place-items: center;
  border-radius: 50%;
  color: #053040;
  background: linear-gradient(135deg, #4ae5d3, #24bfd0);
  box-shadow: 0 16px 32px -16px rgba(20, 170, 180, 0.9);
  opacity: 0;
  visibility: hidden;
  transform: translateY(10px);
  transition: opacity 0.3s var(--ease), transform 0.3s var(--ease),
    visibility 0.3s;
}

.to-top.is-visible {
  opacity: 1;
  visibility: visible;
  transform: none;
}

.to-top svg {
  width: 18px;
  height: 18px;
}

/* ---------- 滚动动效 ---------- */
[data-reveal] {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.8s var(--ease), transform 0.8s var(--ease);
  transition-delay: var(--delay, 0ms);
}

[data-reveal].is-visible {
  opacity: 1;
  transform: none;
}

/* ---------- 响应式 ---------- */
@media (max-width: 1120px) {
  .hero__visual {
    grid-template-columns: minmax(0, 1fr);
    gap: 18px;
  }

  .rail {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .rail__card:hover {
    transform: translateY(-3px);
  }

  .arch__four {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (max-width: 1024px) {
  .hero__inner {
    grid-template-columns: minmax(0, 1fr);
    padding-top: 44px;
  }

  .hero__visual {
    order: 2;
    width: min(560px, 100%);
    margin-inline: auto;
  }

  .coverage__grid {
    grid-template-columns: minmax(0, 1fr);
  }

  .coverage__map {
    margin-top: 4px;
  }

  .about__top {
    grid-template-columns: minmax(0, 1fr);
    gap: 26px;
  }

  .about__top .h2 {
    max-width: none;
  }

  .about__dirs {
    grid-template-columns: minmax(0, 1fr);
  }

  .contact-card {
    grid-template-columns: minmax(0, 1fr);
  }

  .scene-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .scene:last-child {
    grid-column: 1 / -1;
  }
}

@media (max-width: 900px) {
  .header__inner {
    height: 66px;
  }

  .nav-toggle {
    display: flex;
  }

  .header__cta {
    display: none;
  }

  .nav {
    position: fixed;
    left: 0;
    right: 0;
    top: 66px;
    z-index: 90;
    flex-direction: column;
    align-items: stretch;
    gap: 2px;
    padding: 10px 20px 22px;
    background: #ffffff;
    border-bottom: 1px solid rgba(11, 32, 51, 0.08);
    box-shadow: 0 30px 50px -30px rgba(8, 28, 52, 0.4);
    opacity: 0;
    visibility: hidden;
    transform: translateY(-10px);
    transition: opacity 0.25s var(--ease), transform 0.25s var(--ease),
      visibility 0.25s;
  }

  .nav.is-open {
    opacity: 1;
    visibility: visible;
    transform: none;
  }

  .nav a {
    padding: 13px 10px;
    font-size: 15px;
    border-radius: 8px;
  }

  .nav__cta {
  display: none;
}

.nav a.is-active::after {
    display: none;
  }

  .nav a.is-active {
    background: #eef9fa;
  }

  .nav .nav__cta {
    display: flex;
    justify-content: center;
    align-items: center;
    margin-top: 10px;
    padding: 13px 10px;
    border-radius: 10px;
    font-size: 15px;
    font-weight: 600;
    color: #04222e;
    background: linear-gradient(135deg, #4ae5d3, #20c3cd);
  }

  .bases__grid {
    grid-template-columns: minmax(0, 1fr);
  }

  .stats {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .footer__grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 32px;
  }

  .footer__brand {
    grid-column: 1 / -1;
  }
}

@media (max-width: 700px) {
  .container {
    width: calc(100% - 36px);
  }

  .section {
    padding: 56px 0;
  }

  .hero__badge {
    font-size: 11.5px;
  }

  .hero h1 {
    font-size: clamp(30px, 8.6vw, 40px);
  }

  .hero__actions .btn {
    flex: 1 1 100%;
  }

  .hero__meta {
    gap: 8px 18px;
    font-size: 12px;
  }

  .scene-grid {
    grid-template-columns: minmax(0, 1fr);
  }

  .scene:last-child {
    grid-column: auto;
  }

  .arch__four {
    grid-template-columns: minmax(0, 1fr);
  }

  .arch__main {
    flex-direction: column;
    align-items: flex-start;
    gap: 14px;
  }

  .contact-form {
    padding: 20px;
  }

  .form-grid {
    grid-template-columns: 1fr;
  }

  .coverage {
    border-radius: 20px;
    padding: 24px 18px 20px;
  }

  .coverage__stats {
    gap: 28px;
  }

  .coverage__stat b {
    font-size: 28px;
  }

  .stat {
    padding: 20px 16px;
  }

  .footer__bottom {
    justify-content: flex-start;
  }

  .to-top {
    right: 14px;
    bottom: 16px;
  }
}

@media (max-width: 420px) {
  .rail {
    grid-template-columns: minmax(0, 1fr);
  }

  .contact-list div {
    grid-template-columns: minmax(0, 1fr);
    gap: 2px;
  }
}

/* ---------- 动效降级 ---------- */
@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  *,
  *::before,
  *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
  }

  [data-reveal] {
    opacity: 1;
    transform: none;
  }
}