:root {
  --black: #050505;
  --ink: #151515;
  --muted: #6f706c;
  --line: #d8d4cc;
  --paper: #eee9df;
  --stone: #c8bda8;
  --amber: #b98146;
  --white: #f8f6f1;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

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

body.menu-open {
  overflow: hidden;
}

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

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

.site-header {
  position: fixed;
  z-index: 20;
  top: 0;
  left: 0;
  right: 0;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 24px 42px;
  color: var(--white);
  transition: background 0.25s ease, padding 0.25s ease, border-color 0.25s ease;
}

.site-header.is-scrolled {
  padding-block: 16px;
  background: rgba(5, 5, 5, 0.86);
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
  backdrop-filter: blur(16px);
}

.brand,
.site-nav {
  display: flex;
  align-items: center;
}

.brand {
  gap: 12px;
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0.16em;
}

.brand-logo {
  width: 42px;
  height: 42px;
  border-radius: 50%;
  object-fit: cover;
  box-shadow: 0 0 0 1px rgba(185, 129, 70, 0.42);
}

.site-nav {
  gap: 28px;
  font-size: 13px;
  text-transform: uppercase;
}

.site-nav a {
  opacity: 0.78;
  transition: opacity 0.2s ease;
}

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

.social-links {
  display: flex;
  align-items: center;
  gap: 16px;
  margin-left: 18px;
  padding-left: 26px;
  border-left: 1px solid rgba(248, 246, 241, 0.2);
}

.social-links a {
  display: grid;
  place-items: center;
  width: 24px;
  height: 24px;
  opacity: 0.82;
  transition: opacity 0.2s ease, transform 0.2s ease, color 0.2s ease;
}

.social-links a:hover {
  color: var(--amber);
  opacity: 1;
  transform: translateY(-1px);
}

.social-links svg {
  width: 18px;
  height: 18px;
  fill: none;
  stroke: currentColor;
  stroke-width: 1.9;
  stroke-linecap: round;
  stroke-linejoin: round;
}

.social-links svg path:first-child,
.social-links svg rect {
  fill: none;
}

.social-links a[aria-label="YouTube"] svg path:first-child,
.social-links a[aria-label="LinkedIn"] svg path,
.social-links a[aria-label="WeChat"] svg path:first-child {
  fill: currentColor;
  stroke: currentColor;
}

.social-links a[aria-label="YouTube"] svg path:last-child {
  fill: var(--black);
  stroke: var(--black);
}

.social-links a[aria-label="WeChat"] svg circle {
  fill: var(--black);
  stroke: var(--black);
}

.menu-toggle {
  display: none;
}

.hero {
  position: relative;
  min-height: 96vh;
  overflow: hidden;
  background: var(--black);
  color: var(--white);
}

.hero-image {
  position: absolute;
  inset: 0;
  height: 100%;
  object-fit: cover;
}

.hero-shade {
  position: absolute;
  inset: 0;
  background:
    linear-gradient(90deg, rgba(5, 5, 5, 0.88), rgba(5, 5, 5, 0.46) 42%, rgba(5, 5, 5, 0.08)),
    linear-gradient(0deg, rgba(5, 5, 5, 0.68), transparent 44%);
}

.hero-content {
  position: relative;
  z-index: 1;
  width: min(760px, calc(100% - 48px));
  padding: 22vh 0 120px 7vw;
}

.eyebrow,
.section-kicker {
  margin: 0 0 22px;
  color: var(--amber);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.18em;
  text-transform: uppercase;
}

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

h1 {
  margin-bottom: 28px;
  font-size: clamp(48px, 7vw, 112px);
  line-height: 0.98;
  font-weight: 500;
  max-width: 900px;
}

.hero-copy {
  max-width: 620px;
  color: rgba(248, 246, 241, 0.78);
  font-size: 18px;
  line-height: 1.8;
}

.hero-actions {
  display: flex;
  gap: 14px;
  flex-wrap: wrap;
  margin-top: 36px;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 46px;
  padding: 0 22px;
  border: 1px solid currentColor;
  border-radius: 2px;
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  transition: transform 0.2s ease, background 0.2s ease, color 0.2s ease;
}

.button:hover {
  transform: translateY(-2px);
}

.button-primary {
  background: var(--white);
  color: var(--black);
  border-color: var(--white);
}

.button-ghost {
  color: var(--white);
}

.hero-meta {
  position: absolute;
  z-index: 1;
  left: 7vw;
  right: 7vw;
  bottom: 32px;
  display: flex;
  justify-content: space-between;
  gap: 20px;
  color: rgba(248, 246, 241, 0.66);
  font-size: 12px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

section {
  padding: 100px 7vw;
}

.section-dark {
  background: var(--black);
  color: var(--white);
}

.intro-grid,
.contact {
  display: grid;
  grid-template-columns: 1.2fr 0.8fr;
  gap: 8vw;
  align-items: start;
}

.intro h2,
.section-heading h2,
.contact h2 {
  font-size: clamp(32px, 4.5vw, 64px);
  line-height: 1.08;
  font-weight: 500;
}

.intro p,
.contact p {
  color: rgba(248, 246, 241, 0.7);
  font-size: 17px;
  line-height: 1.9;
}

.section-heading {
  display: flex;
  justify-content: space-between;
  gap: 42px;
  align-items: end;
  margin-bottom: 48px;
}

.section-heading h2 {
  max-width: 780px;
  margin-bottom: 0;
}

.portfolio-filter {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin: -20px 0 34px;
}

.portfolio-filter button {
  border: 1px solid rgba(248, 246, 241, 0.2);
  border-radius: 0;
  background: transparent;
  color: rgba(248, 246, 241, 0.72);
  padding: 10px 14px;
  font-size: 11px;
  font-family: inherit;
  cursor: pointer;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  transition: background 0.2s ease, border-color 0.2s ease, color 0.2s ease, transform 0.2s ease;
}

.portfolio-filter button:hover,
.portfolio-filter button.is-active {
  background: var(--white);
  border-color: var(--white);
  color: var(--black);
}

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

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

.service-grid article {
  min-height: 320px;
  padding: 30px;
  border-right: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

.service-grid span,
.timeline span {
  color: var(--amber);
  font-size: 13px;
  font-weight: 700;
}

.service-grid h3,
.timeline h3 {
  font-size: 24px;
  font-weight: 500;
}

.service-grid p,
.timeline p,
.faq p {
  color: var(--muted);
  line-height: 1.8;
}

.work-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  grid-auto-rows: 240px;
  gap: 18px;
}

.project {
  position: relative;
  overflow: hidden;
  background: #222;
}

.project.is-hidden {
  display: none;
}

.project-large {
  grid-column: span 2;
  grid-row: span 2;
}

.project-tall {
  grid-row: span 2;
}

.project img {
  height: 100%;
  object-fit: cover;
  opacity: 0.84;
  transition: transform 0.5s ease, opacity 0.5s ease;
}

.project:hover img {
  transform: scale(1.04);
  opacity: 1;
}

.project::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(0deg, rgba(0, 0, 0, 0.74), transparent 54%);
}

.project div {
  position: absolute;
  z-index: 1;
  left: 24px;
  right: 24px;
  bottom: 22px;
}

.project p {
  margin-bottom: 8px;
  color: rgba(248, 246, 241, 0.62);
  font-size: 12px;
  text-transform: uppercase;
}

.project h3 {
  margin-bottom: 0;
  color: var(--white);
  font-size: 28px;
  font-weight: 500;
}

.metrics {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1px;
  padding-block: 0;
  background: var(--line);
}

.metric {
  background: var(--paper);
  padding: 54px 24px;
}

.metric strong {
  display: block;
  margin-bottom: 12px;
  font-size: clamp(44px, 6vw, 84px);
  font-weight: 500;
  line-height: 1;
}

.metric span,
.client-row span,
.site-footer {
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: 0.11em;
  font-size: 12px;
}

.split-list {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1px;
  background: var(--line);
}

.split-list article {
  min-height: 260px;
  padding: 34px;
  background: var(--paper);
}

.split-list h3,
.benefit-grid h3 {
  margin-bottom: 18px;
  font-size: 24px;
  font-weight: 500;
}

.split-list p,
.benefit-grid p {
  color: var(--muted);
  line-height: 1.8;
}

.benefit-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  border-top: 1px solid rgba(255, 255, 255, 0.14);
  border-left: 1px solid rgba(255, 255, 255, 0.14);
}

.benefit-grid article {
  min-height: 230px;
  padding: 30px;
  border-right: 1px solid rgba(255, 255, 255, 0.14);
  border-bottom: 1px solid rgba(255, 255, 255, 0.14);
}

.benefit-grid p {
  color: rgba(248, 246, 241, 0.68);
}

.timeline {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 28px;
}

.timeline-five {
  grid-template-columns: repeat(5, 1fr);
}

.timeline article {
  padding-top: 24px;
  border-top: 1px solid var(--line);
}

.clients {
  padding-block: 100px;
}

.client-row {
  display: grid;
  grid-template-columns: repeat(6, 1fr);
  gap: 1px;
  border: 1px solid rgba(255, 255, 255, 0.14);
}

.client-row span {
  color: rgba(248, 246, 241, 0.72);
  display: grid;
  place-items: center;
  min-height: 96px;
  border-right: 1px solid rgba(255, 255, 255, 0.14);
}

.client-row span:last-child {
  border-right: 0;
}

.client-list {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1px;
  border-top: 1px solid rgba(255, 255, 255, 0.14);
  border-left: 1px solid rgba(255, 255, 255, 0.14);
}

.client-list ul {
  margin: 0;
  padding: 28px 30px;
  list-style: none;
  border-right: 1px solid rgba(255, 255, 255, 0.14);
  border-bottom: 1px solid rgba(255, 255, 255, 0.14);
}

.client-list li {
  color: rgba(248, 246, 241, 0.76);
  font-size: 14px;
  line-height: 1.65;
}

.client-list li + li {
  margin-top: 9px;
}

.faq-list {
  max-width: 920px;
  margin-left: auto;
}

details {
  border-top: 1px solid var(--line);
  padding: 24px 0;
}

details:last-child {
  border-bottom: 1px solid var(--line);
}

summary {
  cursor: pointer;
  list-style: none;
  font-size: 22px;
}

summary::-webkit-details-marker {
  display: none;
}

summary::after {
  content: "+";
  float: right;
  color: var(--amber);
}

details[open] summary::after {
  content: "-";
}

.contact-form {
  display: grid;
  gap: 18px;
}

.contact-links {
  display: grid;
  gap: 12px;
  margin-top: 30px;
}

.contact-links a {
  color: var(--white);
  font-size: 13px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
}

.contact-form label {
  display: grid;
  gap: 10px;
  color: rgba(248, 246, 241, 0.72);
  font-size: 12px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

input,
textarea {
  width: 100%;
  border: 0;
  border-bottom: 1px solid rgba(248, 246, 241, 0.32);
  border-radius: 0;
  padding: 14px 0;
  background: transparent;
  color: var(--white);
  font: inherit;
  outline: 0;
}

input:focus,
textarea:focus {
  border-bottom-color: var(--white);
}

.site-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  padding: 28px 7vw;
  background: var(--black);
  border-top: 1px solid rgba(255, 255, 255, 0.12);
}

.footer-brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  color: rgba(248, 246, 241, 0.86);
}

.footer-brand img {
  width: 34px;
  height: 34px;
  border-radius: 50%;
  object-fit: cover;
}

@media (max-width: 980px) {
  .service-grid,
  .metrics,
  .timeline,
  .timeline-five,
  .split-list,
  .benefit-grid {
    grid-template-columns: repeat(2, 1fr);
  }

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

  .client-row {
    grid-template-columns: repeat(3, 1fr);
  }

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

  .intro-grid,
  .contact {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 720px) {
  .site-header {
    padding: 18px 20px;
  }

  .brand {
    gap: 10px;
    font-size: 12px;
  }

  .brand-logo {
    width: 36px;
    height: 36px;
  }

  .menu-toggle {
    width: 42px;
    height: 42px;
    border: 1px solid rgba(255, 255, 255, 0.36);
    background: rgba(5, 5, 5, 0.18);
    color: var(--white);
    display: grid;
    place-items: center;
    gap: 0;
  }

  .menu-toggle span {
    width: 18px;
    height: 1px;
    background: currentColor;
  }

  .site-nav {
    position: fixed;
    inset: 72px 16px auto;
    display: none;
    padding: 22px;
    background: rgba(5, 5, 5, 0.94);
    border: 1px solid rgba(255, 255, 255, 0.14);
    backdrop-filter: blur(18px);
    flex-direction: column;
    align-items: flex-start;
    gap: 20px;
  }

  .social-links {
    width: 100%;
    margin: 4px 0 0;
    padding: 18px 0 0;
    border-left: 0;
    border-top: 1px solid rgba(248, 246, 241, 0.16);
    gap: 18px;
  }

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

  .hero {
    min-height: 92vh;
  }

  .hero-content {
    width: calc(100% - 40px);
    padding: 160px 0 120px 20px;
  }

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

  .hero-meta,
  .section-heading,
  .site-footer {
    flex-direction: column;
    align-items: flex-start;
  }

  section {
    padding: 72px 20px;
  }

  .service-grid,
  .work-grid,
  .metrics,
  .timeline,
  .timeline-five,
  .client-row,
  .client-list,
  .split-list,
  .benefit-grid {
    grid-template-columns: 1fr;
  }

  .project,
  .project-large,
  .project-tall {
    grid-column: span 1;
    grid-row: span 1;
    min-height: 320px;
  }

  .client-row span {
    border-right: 0;
    border-bottom: 1px solid rgba(255, 255, 255, 0.14);
  }
}