:root {
  --ink: #102033;
  --muted: #637083;
  --line: #dbe2ea;
  --blue: #1769aa;
  --blue-dark: #0b3f70;
  --cyan: #19a4b8;
  --green: #4b7f52;
  --paper: #ffffff;
  --soft: #f5f7fa;
  --warm: #f7f3ec;
  --shadow: 0 18px 45px rgba(16, 32, 51, 0.14);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--ink);
  font-family: "Microsoft YaHei", "PingFang SC", "Segoe UI", Arial, sans-serif;
  background: var(--paper);
  line-height: 1.6;
}

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

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

.lang-en {
  display: none;
}

body[data-lang="en"] .lang-zh {
  display: none;
}

body[data-lang="en"] .lang-en {
  display: inline;
}

.site-header {
  position: fixed;
  z-index: 20;
  top: 0;
  left: 0;
  right: 0;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  min-height: 76px;
  padding: 14px clamp(20px, 4vw, 64px);
  color: #fff;
  transition: background 0.2s ease, box-shadow 0.2s ease, color 0.2s ease;
}

.site-header.is-scrolled,
.site-header.is-open {
  color: var(--ink);
  background: rgba(255, 255, 255, 0.96);
  box-shadow: 0 8px 26px rgba(16, 32, 51, 0.12);
  backdrop-filter: blur(14px);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  min-width: 0;
}

.brand img {
  width: 46px;
  height: 46px;
  border-radius: 8px;
  object-fit: cover;
  background: #fff;
}

.brand strong,
.brand small {
  display: block;
  white-space: nowrap;
}

.brand strong {
  font-size: 20px;
  letter-spacing: 0;
}

.brand small {
  margin-top: -3px;
  font-size: 11px;
  color: currentColor;
  opacity: 0.78;
  text-transform: uppercase;
}

.site-nav {
  display: flex;
  align-items: center;
  gap: clamp(16px, 2.2vw, 34px);
  font-size: 15px;
  font-weight: 600;
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 10px;
}

.language-toggle {
  min-width: 50px;
  height: 36px;
  padding: 0 12px;
  border: 1px solid currentColor;
  border-radius: 8px;
  color: inherit;
  font: inherit;
  font-size: 13px;
  font-weight: 800;
  cursor: pointer;
  background: rgba(255, 255, 255, 0.08);
}

.site-header.is-scrolled .language-toggle,
.site-header.is-open .language-toggle {
  background: #fff;
}

.site-nav a {
  position: relative;
  padding: 8px 0;
}

.site-nav a::after {
  position: absolute;
  left: 0;
  bottom: 2px;
  width: 100%;
  height: 2px;
  content: "";
  background: var(--cyan);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.2s ease;
}

.site-nav a:hover::after {
  transform: scaleX(1);
}

.menu-button {
  display: none;
  width: 44px;
  height: 44px;
  border: 1px solid currentColor;
  border-radius: 8px;
  color: inherit;
  background: transparent;
}

.menu-button span {
  display: block;
  width: 20px;
  height: 2px;
  margin: 5px auto;
  background: currentColor;
}

.hero {
  position: relative;
  min-height: 92vh;
  display: grid;
  align-items: end;
  overflow: hidden;
  color: #fff;
}

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

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

.hero-overlay {
  background:
    linear-gradient(90deg, rgba(6, 24, 42, 0.9) 0%, rgba(6, 24, 42, 0.68) 42%, rgba(6, 24, 42, 0.22) 100%),
    linear-gradient(180deg, rgba(6, 24, 42, 0.24) 0%, rgba(6, 24, 42, 0.82) 100%);
}

.hero-content {
  position: relative;
  z-index: 1;
  width: min(760px, calc(100% - 40px));
  margin: 0 clamp(20px, 7vw, 104px) clamp(58px, 12vh, 120px);
}

.eyebrow {
  margin: 0 0 12px;
  color: var(--cyan);
  font-size: 13px;
  font-weight: 800;
  letter-spacing: 0;
  text-transform: uppercase;
}

.hero h1 {
  margin: 0;
  font-size: clamp(54px, 9vw, 112px);
  line-height: 1;
  letter-spacing: 0;
}

.hero-lead {
  margin: 18px 0 10px;
  font-size: clamp(22px, 3vw, 34px);
  font-weight: 700;
}

.hero-copy {
  max-width: 690px;
  margin: 0;
  color: rgba(255, 255, 255, 0.88);
  font-size: clamp(16px, 1.6vw, 19px);
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  margin-top: 30px;
}

.primary-button,
.secondary-button,
.contact-form button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 46px;
  padding: 0 22px;
  border-radius: 8px;
  font-weight: 800;
}

.primary-button,
.contact-form button {
  border: 0;
  color: #fff;
  background: var(--cyan);
}

.secondary-button {
  border: 1px solid rgba(255, 255, 255, 0.5);
  color: #fff;
  background: rgba(255, 255, 255, 0.08);
}

.stats {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1px;
  background: var(--line);
}

.stats div {
  padding: clamp(24px, 4vw, 42px);
  background: #fff;
}

.stats strong {
  display: block;
  color: var(--blue-dark);
  font-size: clamp(32px, 4vw, 52px);
  line-height: 1;
}

.stats span {
  display: block;
  margin-top: 10px;
  color: var(--muted);
  font-weight: 700;
}

.section,
.process {
  padding: clamp(62px, 9vw, 108px) clamp(20px, 5vw, 72px);
}

.section-heading {
  width: min(820px, 100%);
  margin-bottom: 34px;
}

.section-heading h2,
.case-copy h2,
.contact h2 {
  margin: 0;
  font-size: clamp(30px, 4vw, 48px);
  line-height: 1.18;
  letter-spacing: 0;
}

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

.service-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 18px;
}

.service-card,
.news-grid article {
  min-height: 250px;
  padding: 26px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fff;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.service-card:hover,
.news-grid article:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow);
}

.icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 46px;
  height: 34px;
  border-radius: 8px;
  color: #fff;
  background: var(--blue-dark);
  font-weight: 900;
}

.service-card h3,
.advantage-list h3,
.news-grid h3 {
  margin: 22px 0 10px;
  font-size: 21px;
  line-height: 1.28;
}

.service-card p,
.advantage-list p,
.news-grid p {
  margin: 0;
  color: var(--muted);
}

.feature-band {
  display: grid;
  grid-template-columns: minmax(320px, 0.82fr) minmax(420px, 1fr);
  gap: clamp(24px, 4vw, 54px);
  align-items: center;
  padding: clamp(62px, 9vw, 108px) clamp(20px, 5vw, 72px);
  background: var(--soft);
}

.case-facts {
  display: grid;
  gap: 12px;
  margin: 28px 0 0;
}

.case-facts div {
  padding: 18px;
  border-left: 4px solid var(--green);
  border-radius: 0 8px 8px 0;
  background: #fff;
}

.case-facts dt {
  color: var(--muted);
  font-size: 13px;
  font-weight: 800;
}

.case-facts dd {
  margin: 4px 0 0;
  font-weight: 800;
}

.case-gallery {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 14px;
}

.case-gallery img {
  width: 100%;
  aspect-ratio: 4 / 3;
  border-radius: 8px;
  object-fit: cover;
  box-shadow: 0 12px 30px rgba(16, 32, 51, 0.12);
}

.advantage-layout {
  display: grid;
  grid-template-columns: minmax(320px, 0.9fr) minmax(360px, 1fr);
  gap: clamp(24px, 4vw, 52px);
  align-items: stretch;
}

.advantage-layout > img {
  width: 100%;
  height: 100%;
  min-height: 520px;
  border-radius: 8px;
  object-fit: cover;
}

.advantage-list {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 16px;
}

.advantage-list article {
  padding: 24px;
  border-radius: 8px;
  background: var(--warm);
}

.process {
  background: var(--blue-dark);
  color: #fff;
}

.process .section-heading p:not(.eyebrow) {
  color: rgba(255, 255, 255, 0.72);
}

.process-list {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1px;
  margin: 0;
  padding: 0;
  list-style: none;
  background: rgba(255, 255, 255, 0.2);
}

.process-list li {
  min-height: 210px;
  padding: 28px;
  background: rgba(255, 255, 255, 0.08);
}

.process-list strong {
  display: block;
  margin-bottom: 12px;
  font-size: 23px;
}

.process-list span {
  color: rgba(255, 255, 255, 0.78);
}

.news-section {
  background: #fff;
}

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

.faq-list {
  display: grid;
  gap: 12px;
  max-width: 960px;
}

.faq-item {
  padding: 20px 24px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fff;
  transition: box-shadow 0.2s ease, border-color 0.2s ease;
}

.faq-item[open] {
  border-color: var(--cyan);
  box-shadow: var(--shadow);
}

.faq-item summary {
  cursor: pointer;
  font-size: 17px;
  font-weight: 800;
  color: var(--ink);
  list-style: none;
  position: relative;
  padding-right: 28px;
}

.faq-item summary::-webkit-details-marker {
  display: none;
}

.faq-item summary::after {
  content: "+";
  position: absolute;
  right: 0;
  top: 50%;
  transform: translateY(-50%);
  width: 22px;
  height: 22px;
  line-height: 20px;
  text-align: center;
  color: var(--cyan);
  font-size: 20px;
  font-weight: 900;
  transition: transform 0.2s ease;
}

.faq-item[open] summary::after {
  content: "−";
}

.faq-item p {
  margin: 12px 0 0;
  color: var(--muted);
  line-height: 1.7;
}

.faq-item p a {
  color: var(--blue);
  font-weight: 700;
  text-decoration: underline;
}

.footer-brand {
  font-style: normal;
}

.footer-brand span,
.footer-brand strong {
  display: block;
}

.footer-brand .copyright {
  margin-top: 6px;
  font-size: 12px;
  color: rgba(255, 255, 255, 0.5);
}

.news-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 18px;
}

.news-grid span {
  color: var(--green);
  font-size: 13px;
  font-weight: 900;
}

.contact {
  display: grid;
  grid-template-columns: minmax(300px, 0.85fr) minmax(360px, 1fr);
  gap: clamp(28px, 6vw, 78px);
  align-items: start;
  padding: clamp(62px, 9vw, 108px) clamp(20px, 5vw, 72px);
  background: var(--soft);
}

.contact-form {
  display: grid;
  gap: 16px;
  padding: 28px;
  border-radius: 8px;
  background: #fff;
  box-shadow: var(--shadow);
}

.contact-panel {
  display: grid;
  gap: 12px;
  padding: 22px;
  border-radius: 8px;
  background: #fff;
  box-shadow: var(--shadow);
}

.contact-item {
  display: grid;
  grid-template-columns: 48px minmax(0, 1fr);
  gap: 15px;
  align-items: center;
  min-height: 82px;
  padding: 14px 16px;
  border: 1px solid var(--line);
  border-radius: 8px;
  transition: border-color 0.2s ease, transform 0.2s ease, background 0.2s ease;
}

.contact-item:hover {
  border-color: var(--cyan);
  background: #f6fbfc;
  transform: translateX(3px);
}

.contact-mark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 42px;
  height: 42px;
  border-radius: 8px;
  color: #fff;
  background: var(--blue-dark);
  font-size: 13px;
  font-weight: 900;
}

.contact-item small,
.contact-item strong {
  display: block;
}

.contact-item small {
  margin-bottom: 3px;
  color: var(--muted);
  font-size: 13px;
  font-weight: 700;
}

.contact-item strong {
  overflow-wrap: anywhere;
  color: var(--ink);
  font-size: 18px;
}

body[data-lang="en"] .hero-content {
  width: min(850px, calc(100% - 40px));
}

body[data-lang="en"] .hero h1 {
  font-size: clamp(48px, 7vw, 92px);
}

body[data-lang="en"] .service-card h3,
body[data-lang="en"] .advantage-list h3,
body[data-lang="en"] .news-grid h3 {
  font-size: 19px;
}

.contact-form label {
  display: grid;
  gap: 7px;
  color: var(--ink);
  font-weight: 800;
}

.contact-form input,
.contact-form select,
.contact-form textarea {
  width: 100%;
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 12px 13px;
  color: var(--ink);
  font: inherit;
  background: #fff;
}

.contact-form textarea {
  resize: vertical;
}

.contact-form button {
  cursor: pointer;
  font: inherit;
}

.site-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  padding: 26px clamp(20px, 5vw, 72px);
  color: rgba(255, 255, 255, 0.84);
  background: #071a2d;
}

.site-footer strong,
.site-footer span {
  display: block;
}

.site-footer span {
  margin-top: 3px;
  font-size: 14px;
  color: rgba(255, 255, 255, 0.62);
}

.site-footer a {
  font-weight: 800;
}

@media (max-width: 980px) {
  .menu-button {
    display: block;
  }

  .site-nav {
    position: absolute;
    top: 76px;
    left: 16px;
    right: 16px;
    display: none;
    padding: 12px;
    border: 1px solid var(--line);
    border-radius: 8px;
    color: var(--ink);
    background: #fff;
    box-shadow: var(--shadow);
  }

  .header-actions {
    margin-left: auto;
  }

  .site-header.is-open .site-nav {
    display: grid;
    gap: 4px;
  }

  .site-nav a {
    padding: 12px;
  }

  .stats,
  .service-grid,
  .process-list {
    grid-template-columns: repeat(2, 1fr);
  }

  .feature-band,
  .advantage-layout,
  .contact {
    grid-template-columns: 1fr;
  }

  .advantage-layout > img {
    min-height: 360px;
  }

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

@media (max-width: 640px) {
  .site-header {
    min-height: 68px;
    padding: 10px 16px;
  }

  .brand img {
    width: 40px;
    height: 40px;
  }

  .brand strong {
    font-size: 18px;
  }

  body[data-lang="en"] .brand strong {
    font-size: 14px;
  }

  .language-toggle {
    min-width: 46px;
    height: 40px;
  }

  .site-nav {
    top: 68px;
  }

  .hero {
    min-height: 88vh;
  }

  .hero-content {
    margin: 0 20px 44px;
  }

  body[data-lang="en"] .hero h1 {
    font-size: 44px;
  }

  .hero-actions {
    display: grid;
  }

  .stats,
  .service-grid,
  .case-gallery,
  .advantage-list,
  .process-list {
    grid-template-columns: 1fr;
  }

  .stats div {
    padding: 24px 20px;
  }

  .section,
  .feature-band,
  .process,
  .contact {
    padding-left: 20px;
    padding-right: 20px;
  }

  .service-card,
  .news-grid article,
  .process-list li,
  .contact-form {
    padding: 22px;
  }

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