:root {
  --blue-900: #0e2d4a;
  --blue-800: #123c62;
  --blue-650: #1e5f91;
  --blue-500: #2473aa;
  --gray-950: #1d242b;
  --gray-800: #303941;
  --gray-600: #66717c;
  --gray-200: #d9e1e8;
  --gray-100: #eef3f6;
  --white: #ffffff;
  --line: rgba(18, 60, 98, 0.16);
  --shadow: 0 10px 24px rgba(14, 45, 74, 0.12);
  --max: 1180px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--gray-950);
  background: #f7f9fb;
  font-family: "Source Han Sans SC", "Noto Sans CJK SC", "Microsoft YaHei", sans-serif;
  line-height: 1.7;
}

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

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

.container {
  width: min(calc(100% - 40px), var(--max));
  margin: 0 auto;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  background: rgba(255, 255, 255, 0.97);
  box-shadow: 0 1px 0 rgba(14, 45, 74, 0.1);
}

.topline {
  background: var(--blue-900);
  color: rgba(255, 255, 255, 0.82);
  font-size: 13px;
}

.topline__inner {
  display: flex;
  justify-content: space-between;
  gap: 18px;
  padding: 7px 0;
}

.navbar {
  background: var(--white);
}

.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 78px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 13px;
}

.brand img {
  width: 66px;
  height: 44px;
  object-fit: contain;
  background: #fff9d9;
  border: 1px solid rgba(130, 51, 27, 0.15);
}

.brand strong {
  display: block;
  color: var(--blue-900);
  font-size: 20px;
  letter-spacing: 0;
  line-height: 1.25;
}

.brand small {
  display: block;
  color: var(--gray-600);
  font-size: 11px;
  letter-spacing: 0;
  margin-top: 2px;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 8px;
}

.nav-links a {
  padding: 25px 14px;
  color: var(--gray-800);
  font-weight: 600;
  font-size: 15px;
  border-bottom: 3px solid transparent;
}

.nav-links a:hover,
.nav-links a:focus {
  color: var(--blue-650);
  border-bottom-color: var(--blue-650);
}

.nav-toggle {
  display: none;
  width: 42px;
  height: 42px;
  padding: 10px;
  border: 1px solid var(--line);
  background: var(--white);
}

.nav-toggle span {
  display: block;
  height: 2px;
  margin: 5px 0;
  background: var(--blue-900);
}

.hero {
  position: relative;
  min-height: clamp(430px, 58vh, 560px);
  display: flex;
  align-items: center;
  overflow: hidden;
  color: var(--white);
}

.hero__bg,
.hero__shade {
  position: absolute;
  inset: 0;
}

.hero__bg {
  background-image: url("./assets/site-materials/asphalt-projects/8b88828b1d98f5dd8554441c413cb0c7.jpg");
  background-size: cover;
  background-position: center 58%;
}

.hero__shade {
  background:
    linear-gradient(90deg, rgba(9, 26, 43, 0.82) 0%, rgba(9, 26, 43, 0.62) 42%, rgba(9, 26, 43, 0.2) 78%),
    linear-gradient(0deg, rgba(9, 26, 43, 0.2), rgba(9, 26, 43, 0.05));
}

.hero__content {
  position: relative;
  z-index: 2;
  padding: 64px 0 122px;
}

.eyebrow,
.section-kicker {
  margin: 0 0 14px;
  color: #9fc8e8;
  font-weight: 700;
  font-size: 14px;
  letter-spacing: 0;
}

.hero h1 {
  max-width: 760px;
  margin: 0;
  font-family: "Songti SC", "Noto Serif CJK SC", serif;
  font-size: clamp(34px, 5vw, 54px);
  line-height: 1.16;
  font-weight: 800;
  letter-spacing: 0;
}

.hero__lead {
  max-width: 660px;
  margin: 24px 0 0;
  color: rgba(255, 255, 255, 0.88);
  font-size: 17px;
}

.hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  margin-top: 38px;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 46px;
  padding: 0 24px;
  font-weight: 700;
  border: 1px solid transparent;
}

.btn-primary {
  background: var(--blue-500);
  color: var(--white);
}

.btn-outline {
  border-color: rgba(255, 255, 255, 0.72);
  color: var(--white);
}

.hero__summary {
  position: absolute;
  left: 50%;
  bottom: 0;
  z-index: 3;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  width: min(calc(100% - 40px), var(--max));
  transform: translateX(-50%);
  background: rgba(14, 45, 74, 0.94);
  border-top: 4px solid var(--blue-500);
}

.hero__summary div {
  padding: 18px 24px;
  border-right: 1px solid rgba(255, 255, 255, 0.18);
}

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

.hero__summary strong,
.hero__summary span {
  display: block;
}

.hero__summary strong {
  font-size: 19px;
}

.hero__summary span {
  color: rgba(255, 255, 255, 0.72);
  font-size: 14px;
  margin-top: 4px;
}

.quick-services {
  background: var(--white);
  padding: 54px 0;
}

.quick-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  border: 1px solid var(--line);
}

.quick-grid article {
  min-height: 188px;
  padding: 24px 20px;
  border-right: 1px solid var(--line);
  background: linear-gradient(180deg, #fff, #f8fbfd);
}

.quick-grid article:last-child {
  border-right: 0;
}

.quick-grid span {
  color: var(--blue-500);
  font-family: Georgia, serif;
  font-size: 30px;
  font-weight: 700;
}

.quick-grid h3 {
  margin: 14px 0 10px;
  color: var(--blue-900);
  font-size: 19px;
}

.quick-grid p,
.section-head p,
.section-copy p,
.business-card p,
.case-slider-copy p,
.contact-list dd,
.footer p {
  color: var(--gray-600);
}

.section {
  padding: 68px 0;
}

.section h2 {
  margin: 0 0 22px;
  color: var(--blue-900);
  font-family: "Songti SC", "Noto Serif CJK SC", serif;
  font-size: clamp(30px, 4vw, 42px);
  line-height: 1.25;
}

.section-copy p {
  margin: 0 0 18px;
  font-size: 16px;
}

.about {
  background:
    linear-gradient(90deg, rgba(238, 243, 246, 0.94), rgba(238, 243, 246, 0.8)),
    repeating-linear-gradient(135deg, rgba(14, 45, 74, 0.05) 0 1px, transparent 1px 16px);
}

.about-grid {
  display: grid;
  grid-template-columns: 0.9fr 1.1fr;
  gap: 52px;
  align-items: center;
}

.about-photo {
  position: relative;
  box-shadow: var(--shadow);
}

.about-photo img {
  width: 100%;
  aspect-ratio: 16 / 10;
  object-fit: cover;
}

.about-note {
  position: absolute;
  left: 0;
  right: 0;
  top: 0;
  width: 100%;
  padding: 22px 26px;
  background: rgba(14, 45, 74, 0.94);
  color: var(--white);
}

.about-note strong,
.about-note span {
  display: block;
}

.about-note span {
  color: rgba(255, 255, 255, 0.72);
  font-size: 14px;
  margin-top: 4px;
}

.business,
.materials {
  background: var(--white);
}

.section-head {
  display: flex;
  justify-content: space-between;
  align-items: end;
  gap: 40px;
  margin-bottom: 34px;
}

.section-head p {
  max-width: 510px;
  margin: 0;
}

.business-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 22px;
}

.business-card {
  background: #f9fbfd;
  border: 1px solid var(--line);
  overflow: hidden;
}

.business-card--wide {
  grid-row: auto;
}

.business-card img {
  width: 100%;
  height: 235px;
  object-fit: cover;
}

.business-card--wide img {
  height: 235px;
}

.business-card div {
  padding: 25px 26px 28px;
}

.business-card span {
  color: var(--blue-650);
  font-size: 13px;
  font-weight: 800;
}

.business-card h3,
.case-slider-copy h3 {
  margin: 7px 0 10px;
  color: var(--blue-900);
  font-size: 22px;
}

.business-card p,
.case-slider-copy p {
  margin: 0;
}

.materials {
  background: #f2f5f7;
}

.material-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 28px;
}

.material-card {
  background: var(--white);
  border: 1px solid var(--line);
  overflow: hidden;
}

.material-card img {
  width: 100%;
  height: 310px;
  object-fit: cover;
  background: #eef1f4;
}

.material-card div {
  padding: 26px 30px 30px;
  text-align: center;
}

.material-card h3 {
  margin: 0 0 12px;
  color: #0b80c7;
  font-size: 24px;
}

.material-card p {
  max-width: 520px;
  margin: 0 auto;
  color: var(--gray-600);
  font-size: 17px;
  font-weight: 600;
}

.cases {
  background: var(--gray-100);
}

.case-slider-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 24px;
}

.case-slider-card {
  display: grid;
  grid-template-columns: 0.32fr 0.68fr;
  gap: 24px;
  align-items: center;
  padding: 28px;
  background: var(--white);
  border: 1px solid var(--line);
  border-left: 4px solid var(--blue-650);
  box-shadow: 0 1px 0 rgba(14, 45, 74, 0.08);
}

.case-slider-copy {
  min-height: 0;
  margin-bottom: 0;
}

.case-slider-copy p {
  color: var(--gray-600);
}

.slider {
  position: relative;
  overflow: hidden;
  border: 1px solid var(--gray-200);
  background: #f7f9fb;
}

.slider-track {
  position: relative;
  width: 100%;
  aspect-ratio: 16 / 9;
}

.slider-track img {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  opacity: 0;
  transition: opacity 0.22s ease;
}

.slider-track img.is-active {
  opacity: 1;
}

.slider-btn {
  position: absolute;
  top: 50%;
  z-index: 2;
  width: 40px;
  height: 48px;
  border: 0;
  background: rgba(14, 45, 74, 0.76);
  color: var(--white);
  font-size: 32px;
  line-height: 1;
  transform: translateY(-50%);
  cursor: pointer;
}

.slider-btn--prev {
  left: 0;
}

.slider-btn--next {
  right: 0;
}

.slider-dots {
  display: flex;
  justify-content: center;
  gap: 8px;
  margin-top: 14px;
}

.case-slider-card .slider-dots {
  grid-column: 2;
}

.slider-dots button {
  width: 9px;
  height: 9px;
  padding: 0;
  border: 0;
  border-radius: 50%;
  background: #b9c5ce;
  cursor: pointer;
}

.slider-dots button.is-active {
  background: var(--blue-650);
}

.contact {
  background: var(--white);
}

.contact-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 0;
  align-items: stretch;
  max-width: 860px;
}

.contact-list {
  margin: 26px 0 0;
}

.contact-list div {
  display: grid;
  grid-template-columns: 112px 1fr;
  gap: 16px;
  padding: 16px 0;
  border-bottom: 1px solid var(--line);
}

.contact-list dt {
  color: var(--blue-900);
  font-weight: 800;
}

.contact-list dd {
  margin: 0;
}

.footer {
  background: var(--gray-950);
  color: var(--white);
  padding: 30px 0;
}

.footer-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

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

.footer p {
  margin: 4px 0 0;
  color: rgba(255, 255, 255, 0.66);
}

.footer a {
  color: rgba(255, 255, 255, 0.82);
}

@media (max-width: 980px) {
  .topline__inner {
    display: none;
  }

  .nav-inner {
    min-height: 68px;
  }

  .nav-toggle {
    display: block;
  }

  .nav-links {
    position: absolute;
    left: 0;
    top: 68px;
    display: none;
    width: 100%;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    background: var(--white);
    border-top: 1px solid var(--line);
    box-shadow: var(--shadow);
  }

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

  .nav-links a {
    padding: 14px 20px;
    border-bottom: 1px solid var(--line);
  }

  .hero {
    min-height: 560px;
  }

  .hero__summary,
  .quick-grid,
  .about-grid,
  .business-grid,
  .material-grid,
  .case-slider-grid,
  .contact-grid {
    grid-template-columns: 1fr;
  }

  .hero__summary div {
    border-right: 0;
    border-bottom: 1px solid rgba(255, 255, 255, 0.18);
    padding: 18px 22px;
  }

  .quick-grid article {
    border-right: 0;
    border-bottom: 1px solid var(--line);
    min-height: auto;
  }

  .quick-grid article:last-child {
    border-bottom: 0;
  }

  .section-head {
    display: block;
  }

  .business-card--wide {
    grid-row: auto;
  }

  .business-card img,
  .business-card--wide img,
  .material-card img {
    height: auto;
    min-height: 0;
    aspect-ratio: 16 / 10;
  }

  .case-slider-copy {
    min-height: 0;
  }

  .case-slider-card {
    grid-template-columns: 1fr;
  }

  .case-slider-card .slider-dots {
    grid-column: auto;
  }
}

@media (max-width: 640px) {
  .container {
    width: min(calc(100% - 28px), var(--max));
  }

  .brand img {
    width: 54px;
    height: 38px;
  }

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

  .brand small {
    display: none;
  }

  .hero {
    min-height: 640px;
  }

  .hero__bg {
    background-position: center;
  }

  .hero__content {
    padding: 54px 0 224px;
  }

  .hero__lead {
    font-size: 16px;
  }

  .hero__summary {
    width: 100%;
  }

  .hero__actions {
    gap: 10px;
  }

  .btn {
    width: 100%;
  }

  .section {
    padding: 52px 0;
  }

  .about-note {
    position: static;
    width: 100%;
  }

  .material-card div,
  .case-slider-card {
    padding: 20px 16px;
  }

  .material-card h3 {
    font-size: 21px;
  }

  .material-card p {
    font-size: 15px;
  }

  .slider-track {
    aspect-ratio: 4 / 3;
  }

  .slider-btn {
    width: 34px;
    height: 42px;
  }

  .contact-list div {
    grid-template-columns: 1fr;
    gap: 3px;
  }

  .footer-inner {
    display: block;
  }
}