:root {
  color-scheme: light;
  --blue: #073b9f;
  --blue-2: #0b58d0;
  --red: #b10012;
  --ink: #151a22;
  --muted: #667085;
  --line: #dfe6f0;
  --paper: #f2f6fc;
  --surface: #ffffff;
  --dark: #111827;
  --shadow: 0 18px 48px rgba(25, 39, 66, 0.12);
  font-family:
    "Microsoft YaHei",
    "PingFang SC",
    "Noto Sans SC",
    Arial,
    sans-serif;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: #ffffff;
  color: var(--ink);
  line-height: 1.6;
}

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

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

button,
input,
textarea {
  font: inherit;
}

.site-header {
  position: fixed;
  top: 0;
  left: 0;
  z-index: 50;
  width: 100%;
  height: 76px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 clamp(22px, 5vw, 72px);
  color: #ffffff;
  transition:
    background 180ms ease,
    box-shadow 180ms ease,
    color 180ms ease;
}

.site-header.is-scrolled,
.site-header.nav-open {
  background: rgba(255, 255, 255, 0.96);
  box-shadow: 0 14px 34px rgba(15, 23, 42, 0.12);
  color: var(--ink);
  backdrop-filter: blur(14px);
}

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

.brand img {
  width: 46px;
  height: 46px;
  flex: 0 0 auto;
  border-radius: 8px;
  background: #ffffff;
  object-fit: contain;
}

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

.brand strong {
  max-width: min(48vw, 390px);
  overflow: hidden;
  font-size: 16px;
  line-height: 1.2;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.brand small {
  margin-top: 2px;
  color: currentColor;
  font-size: 11px;
  letter-spacing: 0.08em;
  opacity: 0.72;
  text-transform: uppercase;
}

.site-nav {
  display: flex;
  align-items: center;
  gap: clamp(18px, 2.5vw, 38px);
  font-size: 15px;
  font-weight: 700;
}

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

.site-nav a::after {
  position: absolute;
  right: 0;
  bottom: 0;
  left: 0;
  height: 2px;
  background: var(--red);
  content: "";
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 160ms ease;
}

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

.nav-toggle {
  display: none;
  width: 44px;
  height: 44px;
  border: 1px solid rgba(255, 255, 255, 0.4);
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.12);
  color: currentColor;
  cursor: pointer;
}

.nav-toggle span {
  display: block;
  width: 18px;
  height: 2px;
  margin: 4px auto;
  border-radius: 999px;
  background: currentColor;
}

.hero {
  position: relative;
  min-height: 94vh;
  overflow: hidden;
  display: grid;
  align-items: center;
  padding: 116px clamp(22px, 6vw, 82px) 158px;
  color: #ffffff;
}

.hero-bg,
.hero-shade {
  position: absolute;
  inset: 0;
}

.hero-bg {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center;
}

.hero-shade {
  background:
    linear-gradient(90deg, rgba(5, 12, 24, 0.9) 0%, rgba(5, 12, 24, 0.76) 43%, rgba(5, 12, 24, 0.2) 100%),
    linear-gradient(180deg, rgba(5, 12, 24, 0.34), rgba(5, 12, 24, 0.7));
}

.hero-inner {
  position: relative;
  z-index: 1;
  width: min(760px, 100%);
}

.eyebrow {
  margin: 0 0 14px;
  color: var(--blue-2);
  font-size: 13px;
  font-weight: 900;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.hero .eyebrow {
  color: #8cc4ff;
}

.hero h1 {
  margin: 0;
  max-width: 860px;
  font-size: clamp(38px, 4.6vw, 64px);
  line-height: 1.08;
  letter-spacing: 0;
}

.hero-lead {
  max-width: 710px;
  margin: 24px 0 0;
  color: rgba(255, 255, 255, 0.86);
  font-size: clamp(16px, 1.35vw, 19px);
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 34px;
}

.btn {
  min-height: 46px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border: 1px solid transparent;
  border-radius: 8px;
  padding: 11px 22px;
  font-weight: 900;
  line-height: 1.25;
  cursor: pointer;
  transition:
    background 160ms ease,
    color 160ms ease,
    border-color 160ms ease,
    transform 160ms ease;
}

.btn:hover {
  transform: translateY(-1px);
}

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

.btn.primary:hover {
  background: #91000f;
}

.btn.outline {
  border-color: rgba(255, 255, 255, 0.45);
  color: #ffffff;
}

.btn.outline:hover {
  background: rgba(255, 255, 255, 0.12);
}

.hero-products {
  position: absolute;
  right: clamp(22px, 6vw, 82px);
  bottom: 34px;
  left: clamp(22px, 6vw, 82px);
  z-index: 1;
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 12px;
}

.hero-products a {
  min-height: 108px;
  display: grid;
  grid-template-columns: 94px minmax(0, 1fr);
  gap: 16px;
  align-items: center;
  border: 1px solid rgba(255, 255, 255, 0.22);
  border-radius: 8px;
  padding: 12px;
  background: rgba(255, 255, 255, 0.1);
  backdrop-filter: blur(14px);
}

.hero-products img {
  width: 94px;
  height: 76px;
  border-radius: 6px;
  background: #ffffff;
  object-fit: cover;
}

.hero-products span {
  overflow-wrap: anywhere;
  font-size: 18px;
  font-weight: 900;
}

.section-inner {
  width: min(1180px, calc(100% - 40px));
  margin: 0 auto;
}

section:not(.hero) {
  padding: clamp(66px, 8vw, 108px) 0;
}

.section-title {
  max-width: 820px;
  margin-bottom: 34px;
}

.section-title.centered {
  margin-right: auto;
  margin-left: auto;
  text-align: center;
}

h2 {
  margin: 0;
  color: var(--ink);
  font-size: clamp(30px, 3.6vw, 48px);
  line-height: 1.16;
  letter-spacing: 0;
}

.section-title p:last-child,
.about-layout p,
.contact-panel p {
  margin: 14px 0 0;
  color: var(--muted);
}

.product-section,
.applications-section {
  background: var(--paper);
}

.product-tabs {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 12px;
  margin-bottom: 32px;
}

.product-tabs button {
  min-width: 138px;
  min-height: 42px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: #ffffff;
  color: var(--ink);
  font-weight: 800;
  cursor: pointer;
}

.product-tabs button.is-active {
  border-color: var(--blue);
  background: var(--blue);
  color: #ffffff;
}

.product-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 22px;
}

.product-card {
  display: flex;
  min-height: 100%;
  flex-direction: column;
  overflow: hidden;
  border-radius: 8px;
  background: var(--surface);
  box-shadow: var(--shadow);
}

.product-card.is-hidden {
  display: none;
}

.product-card img {
  width: 100%;
  aspect-ratio: 4 / 3;
  background: #f8fafc;
  object-fit: cover;
}

.product-card div {
  display: flex;
  flex: 1;
  flex-direction: column;
  padding: 20px;
}

.product-card h3 {
  margin: 0 0 10px;
  font-size: 22px;
  line-height: 1.25;
}

.product-card p {
  margin: 0;
  color: var(--muted);
  font-size: 15px;
}

.product-card a {
  display: inline-flex;
  width: fit-content;
  min-height: 38px;
  align-items: center;
  justify-content: center;
  margin-top: auto;
  border-radius: 999px;
  padding: 8px 18px;
  background: var(--red);
  color: #ffffff;
  font-size: 14px;
  font-weight: 900;
}

.about-layout {
  display: grid;
  grid-template-columns: minmax(0, 0.9fr) minmax(0, 1.1fr);
  gap: clamp(32px, 6vw, 80px);
  align-items: center;
}

.about-points {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 24px;
}

.about-points span {
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: 9px 16px;
  background: #ffffff;
  color: var(--blue);
  font-weight: 900;
}

.about-photos {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 14px;
}

.about-photos img {
  width: 100%;
  height: 420px;
  border-radius: 8px;
  box-shadow: var(--shadow);
  object-fit: cover;
}

.about-photos img:nth-child(2) {
  margin-top: 42px;
  height: 330px;
}

.scenario-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 18px;
}

.scenario-grid article {
  min-height: 190px;
  border-radius: 8px;
  padding: 26px;
  background: #ffffff;
  box-shadow: var(--shadow);
}

.scenario-grid strong {
  display: block;
  color: var(--blue);
  font-size: 22px;
  line-height: 1.25;
}

.scenario-grid p {
  margin: 14px 0 0;
  color: var(--muted);
}

.gallery-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 14px;
}

.gallery-grid img {
  width: 100%;
  aspect-ratio: 1 / 1;
  border-radius: 8px;
  background: #f8fafc;
  box-shadow: var(--shadow);
  object-fit: cover;
}

.contact-section {
  background: var(--dark);
  color: #ffffff;
}

.contact-panel {
  display: grid;
  grid-template-columns: minmax(0, 0.78fr) minmax(0, 1.22fr);
  gap: clamp(28px, 5vw, 70px);
  align-items: start;
}

.contact-panel h2 {
  color: #ffffff;
}

.contact-panel p {
  color: rgba(255, 255, 255, 0.72);
}

.quote-form {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 12px;
  border-radius: 8px;
  padding: clamp(18px, 3vw, 28px);
  background: var(--blue);
}

.quote-form textarea,
.quote-form button,
.form-status {
  grid-column: 1 / -1;
}

.quote-form input,
.quote-form textarea {
  width: 100%;
  border: 0;
  border-radius: 7px;
  background: #ffffff;
  color: var(--ink);
  outline: none;
  padding: 12px 14px;
}

.quote-form textarea {
  resize: vertical;
}

.form-status {
  min-height: 22px;
  margin: 0;
  color: rgba(255, 255, 255, 0.84);
  font-size: 14px;
}

.site-footer {
  background: #0b1220;
  color: rgba(255, 255, 255, 0.76);
}

.footer-layout {
  min-height: 118px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 22px;
}

.footer-layout strong {
  display: block;
  color: #ffffff;
}

.footer-layout p {
  margin: 8px 0 0;
}

.footer-layout a {
  color: #ffffff;
  font-weight: 900;
}

@media (max-width: 1100px) {
  .product-grid,
  .gallery-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

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

@media (max-width: 880px) {
  .site-header {
    height: 68px;
    padding-inline: 18px;
  }

  .brand strong {
    max-width: calc(100vw - 138px);
    font-size: 14px;
  }

  .brand img {
    width: 42px;
    height: 42px;
  }

  .nav-toggle {
    display: block;
  }

  .site-nav {
    position: fixed;
    top: 68px;
    right: 12px;
    left: 12px;
    display: none;
    border: 1px solid var(--line);
    border-radius: 8px;
    padding: 10px;
    background: #ffffff;
    color: var(--ink);
    box-shadow: var(--shadow);
  }

  .site-header.nav-open .site-nav {
    display: grid;
    gap: 2px;
  }

  .site-nav a {
    min-height: 44px;
    display: flex;
    align-items: center;
    border-radius: 6px;
    padding: 10px 12px;
  }

  .site-nav a:hover {
    background: var(--paper);
  }

  .site-nav a::after {
    content: none;
  }

  .hero {
    min-height: auto;
    padding: 104px 20px 28px;
  }

  .hero-bg {
    object-position: 42% center;
  }

  .hero-shade {
    background:
      linear-gradient(180deg, rgba(5, 12, 24, 0.92) 0%, rgba(5, 12, 24, 0.74) 54%, rgba(5, 12, 24, 0.9) 100%),
      linear-gradient(90deg, rgba(5, 12, 24, 0.68), rgba(5, 12, 24, 0.18));
  }

  .hero h1 {
    font-size: clamp(32px, 8.8vw, 44px);
  }

  .hero-actions {
    display: grid;
  }

  .btn {
    width: 100%;
  }

  .hero-products {
    position: relative;
    right: auto;
    bottom: auto;
    left: auto;
    margin-top: 30px;
  }

  .about-layout,
  .contact-panel {
    grid-template-columns: 1fr;
  }

  .about-photos img,
  .about-photos img:nth-child(2) {
    height: 280px;
    margin-top: 0;
  }

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

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

@media (max-width: 620px) {
  .section-inner {
    width: min(100% - 32px, 1180px);
  }

  section:not(.hero) {
    padding: 58px 0;
  }

  .hero-products,
  .product-grid,
  .gallery-grid,
  .about-photos {
    grid-template-columns: 1fr;
  }

  .hero-products a {
    grid-template-columns: 86px minmax(0, 1fr);
  }

  .product-tabs {
    justify-content: flex-start;
    overflow-x: auto;
    padding-bottom: 4px;
  }

  .product-tabs button {
    flex: 0 0 auto;
  }

  .footer-layout {
    min-height: 110px;
    flex-direction: column;
    align-items: flex-start;
    justify-content: center;
  }
}