:root {
  --bg: #ffffff;
  --ink: #1e2930;
  --muted: #66717a;
  --line: #dce5e7;
  --blue: #126da8;
  --green: #2f7d57;
  --green-deep: #155d3a;
  --soft: #f3f7f6;
  --warm: #f8fbfa;
  --heat: #e65a2e;
  --shadow: 0 18px 44px rgba(31, 52, 59, 0.12);
  --max: 1180px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: "Inter", "Segoe UI", "Microsoft YaHei", "Noto Sans SC", Arial, sans-serif;
  line-height: 1.6;
}

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

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

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 32px;
  min-height: 76px;
  padding: 14px clamp(20px, 5vw, 56px);
  background: rgba(255, 255, 255, 0.92);
  border-bottom: 1px solid rgba(220, 229, 231, 0.78);
  backdrop-filter: blur(18px);
}

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

.brand-mark {
  width: 44px;
  height: 44px;
  flex: 0 0 auto;
}

.brand-text {
  display: grid;
  gap: 0;
}

.brand-text strong {
  font-size: 16px;
  line-height: 1.1;
  letter-spacing: 0;
  text-transform: uppercase;
}

.brand-text span {
  font-size: 13px;
  color: var(--muted);
}

.site-nav {
  display: flex;
  align-items: center;
  gap: 22px;
  color: #314049;
  font-size: 14px;
}

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

.site-nav a::after {
  position: absolute;
  left: 0;
  bottom: 0;
  width: 0;
  height: 2px;
  content: "";
  background: var(--green);
  transition: width 180ms ease;
}

.site-nav a:hover::after,
.site-nav a:focus-visible::after {
  width: 100%;
}

.language-switch {
  display: inline-flex;
  align-items: center;
  gap: 2px;
  padding: 3px;
  background: #eef5f3;
  border: 1px solid var(--line);
  border-radius: 8px;
}

.language-switch button {
  min-width: 38px;
  height: 30px;
  padding: 0 8px;
  color: var(--muted);
  background: transparent;
  border: 0;
  border-radius: 6px;
  font: inherit;
  font-size: 12px;
  font-weight: 800;
  cursor: pointer;
}

.language-switch button[aria-pressed="true"] {
  color: #fff;
  background: var(--green);
}

.nav-toggle {
  display: none;
  width: 42px;
  height: 42px;
  padding: 0;
  color: var(--ink);
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 8px;
}

.nav-toggle span {
  display: block;
  width: 18px;
  height: 2px;
  margin: 5px auto;
  background: currentColor;
}

.hero {
  display: grid;
  grid-template-columns: minmax(320px, 0.85fr) minmax(420px, 1.15fr);
  align-items: stretch;
  min-height: min(740px, calc(100vh - 76px));
  overflow: hidden;
  border-bottom: 1px solid var(--line);
}

.hero-copy {
  display: flex;
  flex-direction: column;
  justify-content: center;
  padding: clamp(48px, 7vw, 96px) clamp(24px, 6vw, 78px);
  background:
    linear-gradient(90deg, #fff 72%, rgba(255, 255, 255, 0.78) 100%),
    radial-gradient(circle at 10% 20%, rgba(47, 125, 87, 0.1), transparent 36%);
}

.hero h1 {
  max-width: 620px;
  margin: 0;
  font-size: clamp(42px, 6vw, 76px);
  line-height: 1.05;
  font-weight: 780;
  letter-spacing: 0;
}

.hero p {
  max-width: 610px;
  margin: 28px 0 0;
  color: var(--muted);
  font-size: clamp(17px, 1.65vw, 21px);
}

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

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  min-height: 46px;
  padding: 0 20px;
  border: 1px solid transparent;
  border-radius: 8px;
  font-size: 15px;
  font-weight: 700;
  transition:
    transform 180ms ease,
    box-shadow 180ms ease,
    border-color 180ms ease,
    background 180ms ease;
}

.button svg {
  width: 20px;
  height: 20px;
  fill: none;
  stroke: currentColor;
  stroke-width: 2;
  stroke-linecap: round;
  stroke-linejoin: round;
}

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

.button.primary {
  color: #fff;
  background: var(--green);
  box-shadow: 0 12px 28px rgba(47, 125, 87, 0.22);
}

.button.primary:hover {
  background: var(--green-deep);
}

.button.secondary {
  color: var(--ink);
  background: #fff;
  border-color: #9aa9ae;
}

.hero-media {
  position: relative;
  min-height: 520px;
  background: #eaf2f3;
}

.hero-media::before {
  position: absolute;
  inset: 0 auto 0 0;
  z-index: 1;
  width: 28%;
  content: "";
  background: linear-gradient(90deg, #fff 0%, rgba(255, 255, 255, 0.82) 36%, rgba(255, 255, 255, 0) 100%);
  pointer-events: none;
}

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

.signal-strip {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  max-width: var(--max);
  margin: 0 auto;
  padding: 28px clamp(20px, 4vw, 32px);
  border-bottom: 1px solid var(--line);
}

.signal-strip div {
  display: grid;
  gap: 4px;
  padding: 0 28px;
  border-left: 1px solid var(--line);
}

.signal-strip div:first-child {
  border-left: 0;
}

.signal-strip strong {
  font-size: 17px;
}

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

.section {
  max-width: var(--max);
  margin: 0 auto;
  padding: clamp(76px, 9vw, 112px) clamp(20px, 4vw, 32px);
}

.section-heading {
  max-width: 760px;
  margin-bottom: 44px;
}

.section-heading.split {
  display: flex;
  align-items: end;
  justify-content: space-between;
  gap: 32px;
  max-width: none;
}

.section-heading h2,
.collaboration h2,
.company-info h2 {
  margin: 0;
  font-size: clamp(30px, 4vw, 48px);
  line-height: 1.16;
  letter-spacing: 0;
}

.section-heading p,
.collaboration p {
  margin: 14px 0 0;
  color: var(--muted);
  font-size: 17px;
}

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

.expertise-card {
  min-height: 290px;
  padding: 30px 26px;
  background: var(--warm);
  border: 1px solid var(--line);
  border-radius: 8px;
  transition:
    transform 180ms ease,
    box-shadow 180ms ease,
    border-color 180ms ease;
}

.expertise-card:hover {
  transform: translateY(-4px);
  border-color: rgba(47, 125, 87, 0.36);
  box-shadow: var(--shadow);
}

.icon-shell {
  display: grid;
  place-items: center;
  width: 48px;
  height: 48px;
  margin-bottom: 28px;
  color: var(--green);
  background: #fff;
  border: 1px solid rgba(47, 125, 87, 0.32);
  border-radius: 8px;
}

.icon-shell svg {
  width: 28px;
  height: 28px;
  fill: none;
  stroke: currentColor;
  stroke-width: 1.7;
  stroke-linecap: round;
  stroke-linejoin: round;
}

.expertise-card h3,
.research-list h3,
.process-line h3 {
  margin: 0;
  font-size: 21px;
  line-height: 1.25;
}

.expertise-card p,
.research-list p,
.process-line p {
  margin: 14px 0 0;
  color: var(--muted);
  font-size: 15px;
}

.research-section {
  background:
    linear-gradient(180deg, #fff 0%, #fff 40%, #f2f8f7 40%, #f2f8f7 100%);
  max-width: none;
}

.research-section > * {
  max-width: var(--max);
  margin-left: auto;
  margin-right: auto;
}

.text-link {
  flex: 0 0 auto;
  color: var(--green-deep);
  font-weight: 800;
  border-bottom: 2px solid currentColor;
}

.research-list {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 0;
  overflow: hidden;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 8px;
  box-shadow: var(--shadow);
}

.research-list article {
  min-height: 280px;
  padding: 36px;
  border-left: 1px solid var(--line);
}

.research-list article:first-child {
  border-left: 0;
}

.research-list span {
  display: block;
  margin-bottom: 54px;
  color: var(--blue);
  font-size: 15px;
  font-weight: 800;
}

.collaboration {
  display: grid;
  grid-template-columns: minmax(320px, 0.95fr) minmax(320px, 0.75fr);
  gap: clamp(32px, 6vw, 72px);
  align-items: stretch;
  max-width: var(--max);
  margin: 0 auto;
  padding: clamp(80px, 9vw, 120px) clamp(20px, 4vw, 32px);
}

.collab-copy {
  padding: 16px 0;
}

.check-list {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px 18px;
  padding: 0;
  margin: 32px 0 0;
  list-style: none;
}

.check-list li {
  position: relative;
  padding-left: 28px;
  color: #33434b;
  font-weight: 650;
}

.check-list li::before {
  position: absolute;
  top: 0.15em;
  left: 0;
  width: 18px;
  height: 18px;
  content: "";
  background:
    linear-gradient(135deg, transparent 47%, #fff 47% 57%, transparent 57%) 48% 52% / 60% 60% no-repeat,
    var(--green);
  border-radius: 4px;
}

.collab-panel {
  display: flex;
  flex-direction: column;
  justify-content: flex-end;
  min-height: 460px;
  padding: 38px;
  color: #fff;
  background:
    linear-gradient(150deg, rgba(21, 93, 58, 0.94), rgba(18, 109, 168, 0.84)),
    radial-gradient(circle at 80% 8%, rgba(255, 255, 255, 0.22), transparent 34%);
  border-radius: 8px;
  box-shadow: var(--shadow);
}

.collab-panel p {
  margin: 0 0 16px;
  color: rgba(255, 255, 255, 0.76);
  font-size: 14px;
  font-weight: 800;
}

.collab-panel h3 {
  max-width: 420px;
  margin: 0;
  font-size: clamp(28px, 4vw, 42px);
  line-height: 1.15;
}

.topic-stack {
  display: grid;
  gap: 10px;
  margin-top: 34px;
}

.topic-stack span {
  padding: 12px 14px;
  color: rgba(255, 255, 255, 0.92);
  background: rgba(255, 255, 255, 0.11);
  border: 1px solid rgba(255, 255, 255, 0.2);
  border-radius: 8px;
}

.process-line {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 18px;
}

.process-line article {
  position: relative;
  min-height: 230px;
  padding: 30px 24px;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 8px;
}

.process-line strong {
  display: grid;
  place-items: center;
  width: 40px;
  height: 40px;
  margin-bottom: 42px;
  color: #fff;
  background: var(--blue);
  border-radius: 8px;
}

.company-info {
  display: grid;
  grid-template-columns: minmax(360px, 0.9fr) minmax(320px, 0.75fr);
  gap: clamp(34px, 7vw, 92px);
  max-width: none;
  padding: clamp(78px, 9vw, 112px) max(clamp(20px, 4vw, 56px), calc((100vw - var(--max)) / 2 + 32px));
  background: var(--soft);
  border-top: 1px solid var(--line);
}

dl {
  display: grid;
  gap: 18px;
  margin: 34px 0 0;
}

dl div {
  display: grid;
  grid-template-columns: 96px 1fr;
  gap: 20px;
  padding-bottom: 18px;
  border-bottom: 1px solid var(--line);
}

dt {
  color: var(--muted);
  font-size: 14px;
}

dd {
  margin: 0;
  font-weight: 680;
}

dd a {
  color: var(--green-deep);
  border-bottom: 1px solid rgba(21, 93, 58, 0.34);
}

.contact-form {
  display: grid;
  gap: 18px;
  padding: 30px;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 8px;
  box-shadow: var(--shadow);
}

.form-status {
  min-height: 22px;
  margin: -6px 0 0;
  color: var(--green-deep);
  font-size: 14px;
  font-weight: 700;
}

label {
  display: grid;
  gap: 8px;
  color: #33434b;
  font-size: 14px;
  font-weight: 780;
}

select,
textarea {
  width: 100%;
  border: 1px solid #cbd8dc;
  border-radius: 8px;
  color: var(--ink);
  background: #fff;
  font: inherit;
}

select {
  height: 46px;
  padding: 0 12px;
}

textarea {
  min-height: 150px;
  padding: 12px;
  resize: vertical;
}

.site-footer {
  display: flex;
  justify-content: space-between;
  gap: 20px;
  padding: 24px clamp(20px, 5vw, 56px);
  color: var(--muted);
  font-size: 14px;
  border-top: 1px solid var(--line);
}

@media (max-width: 980px) {
  .site-header {
    gap: 16px;
  }

  .nav-toggle {
    display: block;
  }

  .site-nav {
    position: absolute;
    top: 76px;
    right: 16px;
    display: none;
    width: min(320px, calc(100vw - 32px));
    padding: 12px;
    background: #fff;
    border: 1px solid var(--line);
    border-radius: 8px;
    box-shadow: var(--shadow);
  }

  .site-nav.is-open {
    display: grid;
    gap: 4px;
  }

  .site-nav a {
    padding: 12px;
  }

  .language-switch {
    justify-self: start;
    margin: 8px 12px 4px;
  }

  .hero,
  .collaboration,
  .company-info {
    grid-template-columns: 1fr;
  }

  .hero {
    min-height: 0;
  }

  .hero-copy {
    padding-top: 64px;
    padding-bottom: 44px;
  }

  .hero-media {
    min-height: 360px;
  }

  .signal-strip,
  .expertise-grid,
  .research-list,
  .process-line {
    grid-template-columns: repeat(2, 1fr);
  }

  .research-list article:nth-child(3) {
    grid-column: 1 / -1;
    border-top: 1px solid var(--line);
    border-left: 0;
  }
}

@media (max-width: 680px) {
  .site-header {
    min-height: 68px;
  }

  .brand-text strong {
    font-size: 14px;
  }

  .brand-text span {
    font-size: 12px;
  }

  .site-nav {
    top: 68px;
  }

  .hero h1 {
    font-size: 39px;
  }

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

  .hero-media {
    min-height: 300px;
  }

  .signal-strip,
  .expertise-grid,
  .research-list,
  .process-line,
  .check-list {
    grid-template-columns: 1fr;
  }

  .signal-strip div {
    padding: 18px 0;
    border-top: 1px solid var(--line);
    border-left: 0;
  }

  .signal-strip div:first-child {
    border-top: 0;
  }

  .section-heading.split {
    display: grid;
  }

  .research-list article,
  .research-list article:first-child {
    min-height: auto;
    border-top: 1px solid var(--line);
    border-left: 0;
  }

  .research-list article:first-child {
    border-top: 0;
  }

  .research-list span {
    margin-bottom: 28px;
  }

  .collab-panel {
    min-height: 390px;
    padding: 28px;
  }

  dl div {
    grid-template-columns: 1fr;
    gap: 6px;
  }

  .site-footer {
    display: grid;
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    scroll-behavior: auto !important;
    transition: none !important;
  }
}