:root {
  --bg: #f6f8f7;
  --panel: #ffffff;
  --ink: #18201d;
  --muted: #63706b;
  --line: #dce5e1;
  --teal: #0f766e;
  --teal-dark: #0b4f4a;
  --teal-soft: #edf7f5;
  --brass: #a36d1d;
  --clay: #b65334;
  --clay-soft: #fff2ed;
  --soft: #eaf2ef;
  --footer: #101614;
  --shadow: 0 18px 55px rgba(24, 32, 29, 0.1);
  --max: 1160px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--ink);
  background: var(--bg);
  font-family: ui-sans-serif, -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", Arial, sans-serif;
  line-height: 1.7;
}

body,
button,
input,
textarea {
  letter-spacing: 0;
}

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

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

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

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  background: rgba(246, 248, 247, 0.92);
  border-bottom: 1px solid var(--line);
  backdrop-filter: blur(16px);
}

.nav {
  min-height: 70px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  min-width: 180px;
}

.brand-mark {
  width: 42px;
  height: 42px;
  display: grid;
  place-items: center;
  border-radius: 8px;
  background: var(--ink);
  color: #fff;
  font-family: Georgia, "Times New Roman", serif;
  font-size: 15px;
}

.brand strong {
  display: block;
  font-size: 16px;
  line-height: 1.2;
}

.brand small {
  display: block;
  color: var(--muted);
  font-size: 12px;
  line-height: 1.4;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 24px;
  color: #33413d;
  font-size: 14px;
  white-space: nowrap;
}

.nav-links a {
  padding: 8px 0;
}

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

.hero {
  color: #fff;
  background:
    linear-gradient(90deg, rgba(16, 22, 20, 0.92) 0%, rgba(16, 22, 20, 0.76) 42%, rgba(16, 22, 20, 0.28) 100%),
    url("hero-engineering-studio.webp") center / cover no-repeat;
}

.hero-inner {
  min-height: 560px;
  padding: 74px 0 54px;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: flex-start;
}

.eyebrow,
.section-kicker {
  margin: 0 0 14px;
  color: var(--brass);
  font-size: 13px;
  font-weight: 700;
}

.hero .eyebrow {
  color: #f0bf73;
}

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

h1 {
  max-width: 760px;
  margin-bottom: 24px;
  font-family: ui-serif, "Songti SC", "SimSun", Georgia, serif;
  font-size: 64px;
  font-weight: 600;
  line-height: 1.14;
}

h2 {
  margin-bottom: 16px;
  font-family: ui-serif, "Songti SC", "SimSun", Georgia, serif;
  font-size: 40px;
  font-weight: 600;
  line-height: 1.25;
}

h3 {
  margin-bottom: 12px;
  font-size: 20px;
  line-height: 1.45;
}

.hero-copy {
  max-width: 720px;
  margin-bottom: 28px;
  color: rgba(255, 255, 255, 0.82);
  font-size: 19px;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-bottom: 28px;
}

.button {
  min-height: 48px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  border-radius: 8px;
  padding: 0 18px;
  font-size: 15px;
  font-weight: 700;
}

.button.primary {
  background: var(--teal);
  color: #fff;
  box-shadow: 0 14px 32px rgba(15, 118, 110, 0.32);
}

.button.secondary {
  border: 1px solid rgba(255, 255, 255, 0.36);
  color: #fff;
  background: rgba(255, 255, 255, 0.08);
}

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

.hero-tags {
  list-style: none;
  padding: 0;
  margin: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.hero-tags li {
  min-height: 34px;
  display: inline-flex;
  align-items: center;
  border: 1px solid rgba(255, 255, 255, 0.24);
  border-radius: 8px;
  padding: 0 12px;
  color: rgba(255, 255, 255, 0.82);
  background: rgba(255, 255, 255, 0.08);
  font-size: 13px;
}

.proof-band {
  background: var(--panel);
  border-bottom: 1px solid var(--line);
}

.proof-grid {
  display: grid;
  grid-template-columns: minmax(0, 0.9fr) minmax(0, 1.1fr);
  gap: 48px;
  align-items: center;
  padding: 34px 0;
}

.proof-grid h2 {
  margin-bottom: 0;
  font-size: 30px;
}

.proof-grid p {
  margin-bottom: 0;
  color: var(--muted);
}

.section {
  padding: 78px 0;
}

.section-head {
  max-width: 720px;
  margin-bottom: 34px;
}

.section-head p {
  color: var(--muted);
  margin-bottom: 0;
}

.section-head.two-column {
  max-width: none;
  display: grid;
  grid-template-columns: minmax(0, 0.85fr) minmax(0, 1fr);
  gap: 46px;
  align-items: end;
}

.privacy-note {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 8px;
}

.privacy-note span {
  color: var(--brass);
  font-weight: 700;
}

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

.service-card,
.case-item,
.process li,
.boundary-grid article,
.contact-card {
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--panel);
  box-shadow: 0 10px 28px rgba(24, 32, 29, 0.04);
}

.service-card {
  min-height: 270px;
  position: relative;
  overflow: hidden;
  padding: 30px 22px 22px;
}

.service-card::before {
  content: "";
  position: absolute;
  inset: 0 0 auto;
  height: 5px;
  background: var(--teal);
}

.service-card.accent-teal {
  background: linear-gradient(180deg, var(--teal-soft), var(--panel) 46%);
}

.service-card.accent-clay {
  background: linear-gradient(180deg, var(--clay-soft), var(--panel) 46%);
}

.service-card.accent-clay::before {
  background: var(--clay);
}

.process span,
.case-label {
  display: inline-flex;
  min-height: 28px;
  align-items: center;
  color: var(--brass);
  font-family: Georgia, "Times New Roman", serif;
  font-weight: 700;
}

.service-card p,
.case-item p,
.process p,
.boundary-grid p,
.contact-grid p {
  color: var(--muted);
  margin-bottom: 0;
}

.muted-section {
  background: var(--soft);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.case-list {
  display: grid;
  gap: 12px;
}

.case-item {
  display: grid;
  grid-template-columns: 120px minmax(0, 0.52fr) minmax(0, 1fr);
  gap: 22px;
  align-items: start;
  padding: 24px;
}

.case-item h3 {
  margin-bottom: 0;
}

.case-copy {
  display: grid;
  gap: 12px;
}

.case-advantage {
  padding: 12px 14px;
  border-left: 3px solid var(--teal);
  border-radius: 0 8px 8px 0;
  background: rgba(15, 118, 110, 0.07);
}

.case-advantage strong {
  color: var(--ink);
}

.process {
  list-style: none;
  display: grid;
  grid-template-columns: repeat(5, minmax(0, 1fr));
  gap: 0;
  padding: 0;
  margin: 0;
  border: 1px solid var(--line);
  border-radius: 8px;
  overflow: hidden;
  background: var(--panel);
}

.process li {
  min-height: 220px;
  border: 0;
  border-right: 1px solid var(--line);
  border-radius: 0;
  padding: 22px 18px;
  box-shadow: none;
}

.process li:last-child {
  border-right: 0;
}

.process span {
  margin-bottom: 42px;
}

.boundary-section {
  background: var(--footer);
  color: #fff;
}

.boundary-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}

.boundary-grid article {
  min-height: 280px;
  padding: 28px;
  background: rgba(255, 255, 255, 0.06);
  border-color: rgba(255, 255, 255, 0.14);
  box-shadow: none;
}

.boundary-grid h2 {
  font-size: 34px;
}

.boundary-grid p {
  color: rgba(255, 255, 255, 0.7);
}

.contact-section {
  background: var(--panel);
}

.contact-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(320px, 0.72fr);
  gap: 40px;
  align-items: start;
}

.contact-grid > div {
  max-width: 680px;
}

.contact-card {
  padding: 24px;
  font-style: normal;
}

.contact-card dl {
  margin: 0;
  display: grid;
  gap: 16px;
}

.contact-card dt {
  color: var(--muted);
  font-size: 12px;
  font-weight: 700;
}

.contact-card dd {
  margin: 4px 0 0;
  color: var(--ink);
  overflow-wrap: anywhere;
}

.contact-card a {
  color: var(--teal-dark);
  text-decoration: underline;
  text-underline-offset: 3px;
}

.site-footer {
  padding: 28px 0 42px;
  background: var(--footer);
  color: rgba(255, 255, 255, 0.58);
  font-size: 13px;
}

.footer-inner {
  display: flex;
  justify-content: space-between;
  gap: 20px;
  border-top: 1px solid rgba(255, 255, 255, 0.12);
  padding-top: 22px;
}

.footer-inner p {
  margin-bottom: 0;
}

@media (max-width: 980px) {
  h1 {
    font-size: 48px;
  }

  h2 {
    font-size: 34px;
  }

  .hero-inner {
    min-height: 520px;
    padding: 58px 0 42px;
  }

  .proof-grid,
  .section-head.two-column,
  .contact-grid,
  .boundary-grid {
    grid-template-columns: 1fr;
  }

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

  .case-item {
    grid-template-columns: 1fr;
    gap: 8px;
  }

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

  .process li {
    min-height: 0;
    border-right: 0;
    border-bottom: 1px solid var(--line);
  }

  .process li:last-child {
    border-bottom: 0;
  }

  .process span {
    margin-bottom: 12px;
  }
}

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

  .nav {
    min-height: 64px;
  }

  .brand {
    min-width: 0;
  }

  .brand-mark {
    width: 38px;
    height: 38px;
  }

  .nav-links {
    gap: 14px;
    font-size: 13px;
  }

  .nav-links a:nth-child(2),
  .nav-links a:nth-child(3) {
    display: none;
  }

  .hero {
    background:
      linear-gradient(90deg, rgba(16, 22, 20, 0.94) 0%, rgba(16, 22, 20, 0.78) 62%, rgba(16, 22, 20, 0.48) 100%),
      url("hero-engineering-studio.webp") center / cover no-repeat;
  }

  .hero-inner {
    min-height: 540px;
    padding: 42px 0 34px;
  }

  h1 {
    font-size: 36px;
  }

  h2,
  .boundary-grid h2 {
    font-size: 29px;
  }

  .hero-copy {
    font-size: 16px;
  }

  .button {
    width: 100%;
  }

  .hero-actions {
    width: 100%;
  }

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

  .section {
    padding: 56px 0;
  }

  .footer-inner {
    display: block;
  }

  .footer-inner p + p {
    margin-top: 10px;
  }
}