:root {
  --navy: #0f2b4d;
  --blue: #176dc0;
  --cyan: #17a2c6;
  --red: #d63d32;
  --gold: #dca735;
  --ink: #172236;
  --muted: #667085;
  --line: #dce5ee;
  --paper: #f5f7fa;
  --white: #ffffff;
  --shadow: 0 18px 48px rgba(15, 43, 77, 0.16);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--ink);
  font-family: "Microsoft YaHei", "PingFang SC", Arial, sans-serif;
  background: var(--white);
  line-height: 1.65;
}

img {
  display: block;
  max-width: 100%;
}

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

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  display: flex;
  align-items: center;
  gap: 22px;
  min-height: 74px;
  padding: 12px clamp(18px, 5vw, 72px);
  background: rgba(255, 255, 255, 0.95);
  border-bottom: 1px solid rgba(220, 229, 238, 0.9);
  backdrop-filter: blur(16px);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  min-width: 286px;
}

.brand-mark {
  display: grid;
  place-items: center;
  width: 46px;
  height: 46px;
  color: var(--white);
  font-weight: 900;
  background: linear-gradient(135deg, var(--blue), var(--red));
  border-radius: 8px;
}

.brand strong,
.brand small {
  display: block;
}

.brand strong {
  font-size: 17px;
  line-height: 1.18;
}

.brand small {
  margin-top: 2px;
  color: var(--muted);
  font-size: 12px;
}

.nav-links {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: clamp(12px, 1.6vw, 24px);
  flex: 1;
  font-size: 15px;
}

.nav-links a:hover {
  color: var(--blue);
}

.header-call {
  padding: 10px 16px;
  color: var(--white);
  font-weight: 800;
  background: var(--red);
  border-radius: 8px;
  white-space: nowrap;
}

.menu-toggle {
  display: none;
  width: 42px;
  height: 42px;
  padding: 9px;
  border: 1px solid var(--line);
  background: var(--white);
  border-radius: 8px;
}

.menu-toggle span {
  display: block;
  height: 2px;
  margin: 5px 0;
  background: var(--navy);
}

.hero {
  position: relative;
  min-height: calc(100vh - 74px);
  display: flex;
  align-items: center;
  overflow: hidden;
  background: #0b213d;
}

.hero-image,
.hero-shade {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
}

.hero-image {
  object-fit: cover;
  object-position: center;
}

.hero-shade {
  background:
    linear-gradient(90deg, rgba(8, 21, 40, 0.9), rgba(8, 21, 40, 0.68) 45%, rgba(8, 21, 40, 0.22)),
    linear-gradient(0deg, rgba(8, 21, 40, 0.64), rgba(8, 21, 40, 0.08) 50%);
}

.hero-content {
  position: relative;
  z-index: 1;
  width: min(780px, calc(100% - 36px));
  margin-left: clamp(18px, 7vw, 96px);
  padding: 82px 0 116px;
  color: var(--white);
}

.eyebrow {
  margin: 0 0 12px;
  color: var(--gold);
  font-size: 14px;
  font-weight: 900;
  letter-spacing: 0;
}

.hero h1,
.section h2,
.contact h2 {
  margin: 0;
  line-height: 1.15;
  letter-spacing: 0;
}

.hero h1 {
  font-size: clamp(42px, 7vw, 82px);
}

.hero-copy {
  max-width: 680px;
  margin: 22px 0 0;
  color: rgba(255, 255, 255, 0.9);
  font-size: clamp(18px, 2vw, 23px);
}

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

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 50px;
  padding: 12px 22px;
  font-weight: 900;
  border-radius: 8px;
}

.btn.primary {
  color: var(--white);
  background: var(--red);
}

.btn.secondary {
  color: var(--white);
  border: 1px solid rgba(255, 255, 255, 0.55);
  background: rgba(255, 255, 255, 0.12);
}

.hero-stats {
  display: grid;
  grid-template-columns: repeat(3, minmax(120px, 1fr));
  gap: 12px;
  width: min(560px, 100%);
  margin: 34px 0 0;
}

.hero-stats div {
  padding: 16px;
  background: rgba(255, 255, 255, 0.13);
  border: 1px solid rgba(255, 255, 255, 0.18);
  border-radius: 8px;
}

.hero-stats dt {
  color: var(--gold);
  font-size: 30px;
  font-weight: 900;
  line-height: 1;
}

.hero-stats dd {
  margin: 8px 0 0;
  color: rgba(255, 255, 255, 0.88);
}

.seo-strip {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  justify-content: center;
  padding: 18px clamp(18px, 5vw, 72px);
  background: var(--navy);
}

.seo-strip span {
  padding: 8px 13px;
  color: var(--white);
  background: rgba(255, 255, 255, 0.11);
  border: 1px solid rgba(255, 255, 255, 0.16);
  border-radius: 8px;
  font-size: 14px;
  font-weight: 700;
}

.section {
  padding: clamp(70px, 9vw, 112px) clamp(18px, 5vw, 72px);
}

.section-heading {
  max-width: 880px;
  margin-bottom: 34px;
}

.section h2,
.contact h2 {
  font-size: clamp(30px, 4vw, 48px);
}

.section-heading p:not(.eyebrow),
.fault-copy p,
.models-copy p,
.contact p {
  color: var(--muted);
  font-size: 17px;
}

.service-grid,
.fault-grid,
.promise-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
}

.service-grid article,
.fault-grid article,
.promise-grid article,
.timeline article,
.model-columns article,
.faq-list details {
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: 8px;
  box-shadow: 0 10px 26px rgba(15, 43, 77, 0.06);
}

.service-grid article {
  min-height: 238px;
  padding: 24px;
}

.service-grid span {
  display: inline-block;
  margin-bottom: 20px;
  color: var(--red);
  font-weight: 900;
}

.service-grid h3,
.timeline h3,
.promise-grid h3,
.model-columns h3 {
  margin: 0 0 8px;
  font-size: 21px;
}

.service-grid p,
.timeline p,
.promise-grid p,
.model-columns p,
.faq-list p {
  margin: 0;
  color: var(--muted);
}

.fault-section,
.promise,
.faq {
  background: var(--paper);
}

.fault-section {
  display: grid;
  grid-template-columns: minmax(260px, 0.72fr) minmax(360px, 1.28fr);
  gap: clamp(30px, 5vw, 70px);
  align-items: start;
}

.fault-copy {
  position: sticky;
  top: 104px;
}

.fault-grid {
  grid-template-columns: repeat(3, 1fr);
}

.fault-grid article {
  min-height: 132px;
  padding: 20px;
  background:
    linear-gradient(145deg, rgba(23, 109, 192, 0.08), rgba(23, 162, 198, 0.03)),
    var(--white);
}

.fault-grid b,
.fault-grid span {
  display: block;
}

.fault-grid b {
  margin-bottom: 10px;
  color: var(--navy);
  font-size: 19px;
}

.fault-grid span {
  color: var(--muted);
  font-size: 15px;
}

.timeline {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
  counter-reset: process;
}

.timeline article {
  position: relative;
  padding: 24px;
  overflow: hidden;
}

.timeline article::after {
  content: "";
  position: absolute;
  right: -34px;
  bottom: -34px;
  width: 96px;
  height: 96px;
  background: rgba(23, 109, 192, 0.08);
  border-radius: 50%;
}

.timeline span {
  display: grid;
  place-items: center;
  width: 42px;
  height: 42px;
  margin-bottom: 18px;
  color: var(--white);
  font-size: 20px;
  font-weight: 900;
  background: var(--blue);
  border-radius: 8px;
}

.models {
  display: grid;
  grid-template-columns: minmax(300px, 0.75fr) minmax(360px, 1.25fr);
  gap: clamp(30px, 6vw, 74px);
  align-items: start;
}

.model-columns {
  display: grid;
  gap: 16px;
}

.model-columns article {
  padding: 24px;
}

.promise-grid {
  grid-template-columns: repeat(3, 1fr);
}

.promise-grid article {
  padding: 24px;
}

.promise-grid h3 {
  color: var(--navy);
}

.faq-list {
  display: grid;
  gap: 14px;
}

.faq-list details {
  padding: 20px 22px;
}

.faq-list summary {
  cursor: pointer;
  color: var(--navy);
  font-size: 18px;
  font-weight: 900;
}

.faq-list p {
  padding-top: 12px;
}

.contact {
  display: grid;
  grid-template-columns: 1fr minmax(280px, 440px);
  gap: clamp(28px, 6vw, 72px);
  padding: clamp(62px, 8vw, 100px) clamp(18px, 5vw, 72px);
  color: var(--white);
  background:
    linear-gradient(135deg, rgba(15, 43, 77, 0.98), rgba(23, 109, 192, 0.86)),
    var(--navy);
}

.contact p {
  max-width: 760px;
  color: rgba(255, 255, 255, 0.78);
}

address {
  display: grid;
  gap: 12px;
  align-self: center;
  padding: 26px;
  font-style: normal;
  background: rgba(255, 255, 255, 0.1);
  border: 1px solid rgba(255, 255, 255, 0.18);
  border-radius: 8px;
}

.phone {
  color: var(--gold);
  font-size: clamp(30px, 4vw, 44px);
  font-weight: 900;
  line-height: 1;
}

footer {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 18px;
  padding: 22px clamp(18px, 5vw, 72px);
  color: rgba(255, 255, 255, 0.8);
  background: #0b1d34;
}

footer a {
  color: var(--white);
}

.footer-info {
  display: flex;
  flex-wrap: wrap;
  gap: 10px 18px;
  align-items: center;
}

.icp-link {
  color: rgba(255, 255, 255, 0.82);
  text-decoration: underline;
  text-underline-offset: 3px;
}

.desktop-float {
  position: fixed;
  right: 18px;
  top: 50%;
  z-index: 30;
  display: grid;
  gap: 6px;
  width: 174px;
  padding: 16px 14px;
  color: var(--white);
  background: linear-gradient(160deg, var(--red), #a92520);
  border: 1px solid rgba(255, 255, 255, 0.18);
  border-radius: 8px;
  box-shadow: 0 14px 32px rgba(15, 43, 77, 0.22);
  transform: translateY(-50%);
}

.desktop-float span,
.desktop-float small {
  color: rgba(255, 255, 255, 0.82);
  font-size: 13px;
}

.desktop-float a {
  color: var(--white);
  font-size: 20px;
  font-weight: 900;
  line-height: 1.1;
}

.floating-call {
  position: fixed;
  right: 18px;
  bottom: 18px;
  z-index: 30;
  display: none;
  padding: 13px 18px;
  color: var(--white);
  font-weight: 900;
  background: var(--red);
  border-radius: 8px;
  box-shadow: 0 10px 28px rgba(214, 61, 50, 0.28);
}

@media (max-width: 1120px) {
  .service-grid,
  .timeline {
    grid-template-columns: repeat(2, 1fr);
  }

  .brand {
    min-width: 250px;
  }
}

@media (max-width: 980px) {
  .site-header {
    justify-content: space-between;
  }

  .menu-toggle {
    display: block;
  }

  .nav-links {
    position: absolute;
    top: 74px;
    left: 0;
    right: 0;
    display: none;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    padding: 10px 18px 18px;
    background: var(--white);
    border-bottom: 1px solid var(--line);
  }

  .nav-links.is-open {
    display: flex;
  }

  .nav-links a {
    padding: 13px 4px;
    border-bottom: 1px solid var(--line);
  }

  .header-call {
    display: none;
  }

  .fault-section,
  .models,
  .contact {
    grid-template-columns: 1fr;
  }

  .fault-copy {
    position: static;
  }

  .fault-grid,
  .promise-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .desktop-float {
    display: none;
  }
}

@media (max-width: 700px) {
  .brand {
    min-width: 0;
  }

  .brand strong {
    font-size: 15px;
  }

  .brand small {
    font-size: 11px;
  }

  .brand-mark {
    width: 42px;
    height: 42px;
  }

  .hero {
    min-height: 720px;
    align-items: flex-end;
  }

  .hero-shade {
    background:
      linear-gradient(0deg, rgba(8, 21, 40, 0.95), rgba(8, 21, 40, 0.64) 58%, rgba(8, 21, 40, 0.16)),
      linear-gradient(90deg, rgba(8, 21, 40, 0.48), transparent);
  }

  .hero-content {
    width: calc(100% - 36px);
    margin: 0 auto;
    padding: 80px 0 112px;
  }

  .hero h1 {
    font-size: 40px;
  }

  .hero-copy {
    font-size: 18px;
  }

  .hero-stats,
  .service-grid,
  .fault-grid,
  .timeline,
  .promise-grid {
    grid-template-columns: 1fr;
  }

  .btn {
    width: 100%;
  }

  .section {
    padding: 64px 18px;
  }

  .seo-strip {
    justify-content: flex-start;
  }

  .floating-call {
    display: inline-flex;
  }

  footer {
    flex-direction: column;
    align-items: flex-start;
  }
}

@media (max-width: 430px) {
  .hero h1 {
    font-size: 35px;
  }

  .section h2,
  .contact h2 {
    font-size: 28px;
  }
}