:root {
  --brand: #b4231a;
  --brand-dark: #7f1d1d;
  --ink: #202124;
  --muted: #62656b;
  --line: #e5e1dc;
  --paper: #ffffff;
  --soft: #f7f4ef;
  --green: #23684f;
  --gold: #b9832e;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--ink);
  background: var(--paper);
  font-family: "Microsoft YaHei", "PingFang SC", Arial, sans-serif;
  letter-spacing: 0;
}

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

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

.site-header {
  position: fixed;
  top: 0;
  left: 0;
  z-index: 20;
  width: 100%;
  height: 72px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  padding: 0 40px;
  color: #fff;
  background: rgba(32, 33, 36, 0.18);
  border-bottom: 1px solid rgba(255, 255, 255, 0.18);
  transition: background 180ms ease, color 180ms ease, box-shadow 180ms ease;
}

.site-header.scrolled {
  color: var(--ink);
  background: rgba(255, 255, 255, 0.96);
  box-shadow: 0 8px 30px rgba(32, 33, 36, 0.08);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  min-width: 132px;
  font-weight: 700;
  font-size: 18px;
}

.brand img {
  width: 36px;
  height: 36px;
  object-fit: contain;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 28px;
  font-size: 15px;
}

.nav-links a {
  opacity: 0.88;
}

.nav-links a:hover {
  opacity: 1;
}

.nav-action,
.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 42px;
  padding: 0 18px;
  border-radius: 6px;
  font-weight: 700;
  white-space: nowrap;
}

.nav-action {
  color: #fff;
  background: var(--brand);
}

.hero {
  position: relative;
  min-height: 78vh;
  overflow: hidden;
  color: #fff;
  display: flex;
  align-items: center;
}

.hero-media {
  position: absolute;
  inset: 0;
  background-image: url("./assets/hero-sign.png");
  background-size: cover;
  background-position: center;
}

.hero-overlay {
  position: absolute;
  inset: 0;
  background: linear-gradient(90deg, rgba(32, 33, 36, 0.78), rgba(32, 33, 36, 0.38) 52%, rgba(32, 33, 36, 0.22));
}

.hero-content {
  position: relative;
  z-index: 1;
  width: min(1120px, calc(100% - 48px));
  margin: 0 auto;
  padding-top: 74px;
}

.eyebrow {
  margin: 0 0 12px;
  color: var(--gold);
  font-size: 14px;
  font-weight: 700;
}

.hero .eyebrow {
  color: #ffd487;
}

h1,
h2,
h3,
p {
  margin-top: 0;
}

h1 {
  max-width: 760px;
  margin-bottom: 20px;
  font-size: 58px;
  line-height: 1.08;
  font-weight: 800;
}

.hero-copy {
  max-width: 680px;
  margin-bottom: 30px;
  color: rgba(255, 255, 255, 0.9);
  font-size: 19px;
  line-height: 1.8;
}

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

.button.primary {
  color: #fff;
  background: var(--brand);
}

.button.secondary {
  color: #fff;
  border: 1px solid rgba(255, 255, 255, 0.78);
  background: rgba(255, 255, 255, 0.08);
}

.metrics {
  width: min(1120px, calc(100% - 48px));
  margin: -42px auto 0;
  position: relative;
  z-index: 3;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: 8px;
  box-shadow: 0 18px 40px rgba(32, 33, 36, 0.12);
}

.metrics div {
  padding: 26px 24px;
  border-right: 1px solid var(--line);
}

.metrics div:last-child {
  border-right: 0;
}

.metrics strong {
  display: block;
  margin-bottom: 6px;
  color: var(--brand);
  font-size: 28px;
}

.metrics span {
  color: var(--muted);
  font-size: 14px;
}

.section {
  width: min(1120px, calc(100% - 48px));
  margin: 0 auto;
  padding: 96px 0;
}

.section-heading {
  max-width: 780px;
  margin-bottom: 34px;
}

.section-heading.narrow {
  max-width: 700px;
}

h2 {
  margin-bottom: 14px;
  font-size: 34px;
  line-height: 1.24;
}

h3 {
  margin-bottom: 10px;
  font-size: 19px;
  line-height: 1.35;
}

.section-heading p,
.image-copy p,
.feature-grid p,
.workflow-step p,
.cta-band p,
.contact-panel p {
  color: var(--muted);
  line-height: 1.8;
}

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

.workflow-step,
.feature-grid article {
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 24px;
  background: var(--paper);
}

.workflow-step span {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 38px;
  height: 30px;
  margin-bottom: 18px;
  border-radius: 4px;
  color: #fff;
  background: var(--green);
  font-weight: 700;
}

.image-section {
  display: grid;
  grid-template-columns: 0.85fr 1.15fr;
  gap: 48px;
  align-items: center;
  border-top: 1px solid var(--line);
}

.mini-list {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 22px;
}

.mini-list span {
  padding: 8px 12px;
  border-radius: 4px;
  color: var(--green);
  background: #eef7f2;
  font-size: 14px;
  font-weight: 700;
}

.gallery-main {
  margin: 0;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--soft);
  overflow: hidden;
}

.gallery-main img {
  width: 100%;
  aspect-ratio: 4 / 3;
  object-fit: contain;
  background: #fff;
}

.gallery-thumbs {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 14px;
}

.gallery-thumbs button {
  min-height: 36px;
  padding: 0 14px;
  border: 1px solid var(--line);
  border-radius: 6px;
  color: var(--ink);
  background: #fff;
  cursor: pointer;
}

.gallery-thumbs button.active {
  color: #fff;
  border-color: var(--brand);
  background: var(--brand);
}

.system-section {
  border-top: 1px solid var(--line);
}

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

.feature-grid article {
  background: var(--soft);
}

.cta-band {
  width: min(1120px, calc(100% - 48px));
  margin: 0 auto 80px;
  padding: 42px;
  display: grid;
  grid-template-columns: 1fr 360px;
  gap: 32px;
  align-items: center;
  color: #fff;
  background: var(--brand-dark);
  border-radius: 8px;
}

.cta-band .eyebrow,
.cta-band p {
  color: rgba(255, 255, 255, 0.82);
}

.contact-panel {
  padding: 24px;
  border: 1px solid rgba(255, 255, 255, 0.22);
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.08);
}

.contact-panel span {
  display: block;
  margin-bottom: 8px;
  color: #ffd487;
  font-weight: 700;
}

.contact-panel strong {
  display: block;
  margin-bottom: 10px;
  font-size: 22px;
}

.site-footer {
  min-height: 72px;
  padding: 0 40px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  color: var(--muted);
  border-top: 1px solid var(--line);
}

.site-footer a {
  color: var(--muted);
  text-decoration: underline;
  text-underline-offset: 3px;
}

.site-footer a:hover {
  color: var(--brand);
}

@media (max-width: 960px) {
  .site-header {
    height: auto;
    padding: 14px 22px;
    flex-wrap: wrap;
  }

  .nav-links {
    order: 3;
    width: 100%;
    justify-content: space-between;
    gap: 12px;
    overflow-x: auto;
    padding-bottom: 2px;
  }

  h1 {
    font-size: 42px;
  }

  .metrics,
  .workflow,
  .feature-grid,
  .image-section,
  .cta-band {
    grid-template-columns: 1fr;
  }

  .metrics div {
    border-right: 0;
    border-bottom: 1px solid var(--line);
  }

  .metrics div:last-child {
    border-bottom: 0;
  }

  .cta-band {
    padding: 30px 24px;
  }
}

@media (max-width: 640px) {
  .site-header {
    color: var(--ink);
    background: rgba(255, 255, 255, 0.96);
  }

  .nav-action {
    min-height: 38px;
    padding: 0 14px;
  }

  .hero {
    min-height: 680px;
  }

  .hero-overlay {
    background: rgba(32, 33, 36, 0.72);
  }

  h1 {
    font-size: 34px;
  }

  h2 {
    font-size: 28px;
  }

  .hero-copy {
    font-size: 17px;
  }

  .section {
    padding: 72px 0;
  }

  .site-footer {
    padding: 22px;
    align-items: flex-start;
    flex-direction: column;
  }
}