:root {
  color-scheme: light dark;
  --home-bg: #f1f2ef;
  --home-surface: #fafbf8;
  --home-surface-strong: #e5e7e1;
  --home-ink: #1d1f1b;
  --home-muted: #62665e;
  --home-line: rgba(29, 31, 27, 0.15);
  --home-accent: #d83f35;
  --home-accent-dark: #b8322a;
  --home-accent-soft: #f1cbc7;
  --home-shadow: rgba(62, 41, 35, 0.16);
  --home-radius: 18px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--home-bg);
  color: var(--home-ink);
  font-family: var(--font-geist-sans, "PingFang SC"), "Microsoft YaHei", sans-serif;
  -webkit-font-smoothing: antialiased;
}

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

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

a,
button {
  -webkit-tap-highlight-color: transparent;
}

.skip-link {
  position: fixed;
  top: -60px;
  left: 16px;
  z-index: 20;
  padding: 10px 14px;
  border-radius: 8px;
  background: var(--home-ink);
  color: var(--home-bg);
}

.skip-link:focus {
  top: 16px;
}

.site-header {
  width: min(1240px, calc(100% - 56px));
  min-height: 72px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: minmax(210px, 1fr) auto minmax(210px, 1fr);
  align-items: center;
  gap: 28px;
}

.brand {
  min-width: 0;
  display: inline-flex;
  align-items: center;
  gap: 11px;
  justify-self: start;
}

.brand-mark {
  width: 42px;
  height: 42px;
  display: grid;
  place-items: center;
  flex: 0 0 auto;
  border-radius: 12px;
  background: var(--home-accent);
  color: #fffaf7;
  font-size: 21px;
  font-weight: 900;
  box-shadow: 0 12px 28px var(--home-shadow);
}

.brand-name {
  display: grid;
  line-height: 1;
}

.brand-name strong {
  font-size: 20px;
  letter-spacing: -0.04em;
}

.brand-name small {
  margin-top: 6px;
  color: var(--home-muted);
  font-size: 9px;
  font-weight: 700;
  letter-spacing: 0.16em;
}

.site-header nav {
  display: flex;
  align-items: center;
  gap: 30px;
  white-space: nowrap;
}

.site-header nav a {
  color: var(--home-muted);
  font-size: 14px;
  font-weight: 720;
}

.site-header nav a:hover,
.site-header nav a:focus-visible,
.footer-links a:hover,
.footer-links a:focus-visible {
  color: var(--home-accent);
}

.header-cta {
  min-height: 42px;
  padding: 0 18px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  justify-self: end;
  border-radius: 999px;
  background: var(--home-ink);
  color: var(--home-bg);
  font-size: 14px;
  font-weight: 800;
  white-space: nowrap;
}

main {
  overflow: hidden;
}

.hero {
  width: min(1240px, calc(100% - 56px));
  min-height: calc(100dvh - 72px);
  margin: 0 auto;
  padding: 30px 0 72px;
  display: grid;
  grid-template-columns: minmax(0, 0.92fr) minmax(430px, 1.08fr);
  align-items: center;
  gap: 72px;
}

.hero-copy {
  padding-bottom: 20px;
}

.hero-kicker {
  margin: 0 0 18px;
  color: var(--home-accent);
  font-size: 13px;
  font-weight: 900;
  letter-spacing: 0.14em;
}

.hero h1 {
  max-width: 680px;
  margin: 0;
  font-size: clamp(52px, 6.3vw, 86px);
  font-weight: 820;
  line-height: 0.98;
  letter-spacing: -0.078em;
}

.hero h1 em {
  display: block;
  padding-bottom: 0.06em;
  color: var(--home-accent);
  font-style: normal;
}

.hero-intro {
  max-width: 480px;
  margin: 26px 0 0;
  color: var(--home-muted);
  font-size: 18px;
  line-height: 1.72;
}

.hero-actions {
  margin-top: 32px;
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.button {
  min-height: 52px;
  padding: 0 25px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: 999px;
  font-weight: 850;
  white-space: nowrap;
  transition: transform 180ms ease, background 180ms ease, border-color 180ms ease;
}

.button:active,
.header-cta:active {
  transform: scale(0.98);
}

.button-primary {
  background: var(--home-accent);
  color: #fffaf7;
  box-shadow: 0 18px 38px var(--home-shadow);
}

.button-primary:hover,
.button-primary:focus-visible {
  background: var(--home-accent-dark);
}

.button-secondary {
  border: 1px solid var(--home-line);
  background: var(--home-surface);
  color: var(--home-ink);
}

.button-secondary:hover,
.button-secondary:focus-visible {
  border-color: var(--home-accent);
}

.hero-visual {
  min-height: 620px;
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(180px, 0.52fr);
  gap: 18px;
  align-items: end;
}

.hero-visual figure {
  height: 620px;
  margin: 0;
  overflow: hidden;
  border-radius: var(--home-radius);
  background: #07100c;
  box-shadow: 0 34px 90px var(--home-shadow);
}

.hero-visual img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 700ms cubic-bezier(0.16, 1, 0.3, 1);
}

.hero-visual:hover img,
.hero-visual:focus-visible img {
  transform: scale(1.025);
}

.hero-visual-copy {
  padding: 26px 0 34px;
  display: grid;
  gap: 10px;
  border-top: 1px solid var(--home-line);
}

.hero-visual-copy span,
.featured-copy span {
  color: var(--home-accent);
  font-size: 12px;
  font-weight: 850;
}

.hero-visual-copy strong {
  font-size: 25px;
  line-height: 1.18;
  letter-spacing: -0.035em;
}

.hero-visual-copy p {
  margin: 0;
  color: var(--home-muted);
  font-size: 13px;
  line-height: 1.6;
}

.promise {
  width: min(1184px, calc(100% - 56px));
  margin: 0 auto 126px;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  border-top: 1px solid var(--home-line);
  border-bottom: 1px solid var(--home-line);
}

.promise p {
  margin: 0;
  padding: 25px 26px;
  display: grid;
  gap: 7px;
  border-right: 1px solid var(--home-line);
}

.promise p:last-child {
  border-right: 0;
}

.promise strong {
  font-size: 16px;
}

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

.featured,
.all-tests,
.method,
.standards,
.closing-cta {
  width: min(1184px, calc(100% - 56px));
  margin: 0 auto;
}

.featured,
.all-tests,
.method {
  padding-bottom: 128px;
}

.section-heading {
  max-width: 720px;
  margin-bottom: 38px;
}

.section-heading h2,
.method-intro h2,
.standards h2,
.closing-cta h2 {
  margin: 0;
  font-size: clamp(38px, 5vw, 64px);
  line-height: 1.05;
  letter-spacing: -0.058em;
}

.section-heading p,
.method-intro p,
.closing-cta p {
  max-width: 640px;
  margin: 18px 0 0;
  color: var(--home-muted);
  font-size: 16px;
  line-height: 1.7;
}

.featured-grid {
  display: grid;
  grid-template-columns: 1.35fr 0.65fr;
  grid-template-rows: 315px 315px;
  gap: 18px;
}

.featured-card {
  overflow: hidden;
  display: grid;
  border-radius: var(--home-radius);
  background: var(--home-surface);
  box-shadow: 0 22px 62px rgba(62, 41, 35, 0.09);
  transition: transform 220ms ease, box-shadow 220ms ease;
}

.featured-card:hover,
.featured-card:focus-visible {
  transform: translateY(-3px);
  box-shadow: 0 28px 72px var(--home-shadow);
}

.featured-main {
  grid-row: 1 / span 2;
  grid-template-columns: 0.94fr 1.06fr;
}

.featured-main img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.featured-copy {
  padding: 30px;
  align-content: end;
  display: grid;
  gap: 12px;
}

.featured-main .featured-copy {
  padding: 44px;
}

.featured-copy h3 {
  margin: 0;
  font-size: clamp(25px, 3vw, 42px);
  line-height: 1.06;
  letter-spacing: -0.045em;
}

.featured-copy p {
  margin: 0;
  color: var(--home-muted);
  line-height: 1.62;
}

.featured-copy > strong {
  margin-top: 16px;
  color: var(--home-accent);
  font-size: 14px;
}

.featured-side {
  grid-template-columns: 0.72fr 1.28fr;
}

.featured-side img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.featured-side .featured-copy {
  padding: 24px;
}

.featured-side .featured-copy h3 {
  font-size: 25px;
}

.all-tests {
  padding-top: 4px;
}

.test-list {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 14px;
}

.test-list a {
  min-height: 126px;
  padding: 12px 18px 12px 12px;
  display: grid;
  grid-template-columns: 78px minmax(0, 1fr) auto;
  align-items: center;
  gap: 17px;
  border: 1px solid var(--home-line);
  border-radius: var(--home-radius);
  background: var(--home-surface);
  transition: transform 180ms ease, border-color 180ms ease;
}

.test-list a:hover,
.test-list a:focus-visible {
  transform: translateY(-2px);
  border-color: var(--home-accent);
}

.test-list img {
  width: 78px;
  height: 100px;
  object-fit: cover;
  border-radius: 12px;
}

.test-list span {
  display: grid;
  gap: 7px;
}

.test-list strong {
  font-size: 20px;
}

.test-list small {
  color: var(--home-muted);
  font-size: 13px;
}

.test-list b {
  color: var(--home-accent);
  font-size: 13px;
  white-space: nowrap;
}

.method {
  display: grid;
  grid-template-columns: 0.9fr 1.1fr;
  align-items: start;
  gap: 86px;
}

.method-intro {
  position: sticky;
  top: 34px;
}

.method-list {
  margin: 0;
  padding: 0;
  list-style: none;
  counter-reset: method;
}

.method-list li {
  min-height: 138px;
  padding: 30px 0;
  display: grid;
  grid-template-columns: minmax(120px, 0.45fr) minmax(0, 1fr);
  align-items: center;
  gap: 24px;
  border-bottom: 1px solid var(--home-line);
}

.method-list li:first-child {
  border-top: 1px solid var(--home-line);
}

.method-list span {
  color: var(--home-accent);
  font-size: 14px;
  font-weight: 850;
}

.method-list strong {
  font-size: 25px;
  line-height: 1.22;
  letter-spacing: -0.03em;
}

.standards {
  padding: 70px;
  display: grid;
  grid-template-columns: 0.86fr 1.14fr;
  gap: 78px;
  border-radius: var(--home-radius);
  background: var(--home-surface-strong);
}

.standards-copy > p {
  margin: 0 0 18px;
  color: var(--home-accent);
  font-size: 13px;
  font-weight: 850;
}

.standards-principles {
  display: grid;
  gap: 0;
}

.standards-principles article {
  padding: 24px 0;
  border-bottom: 1px solid var(--home-line);
}

.standards-principles article:first-child {
  padding-top: 0;
}

.standards-principles article:last-child {
  padding-bottom: 0;
  border-bottom: 0;
}

.standards-principles strong {
  font-size: 21px;
}

.standards-principles p {
  margin: 8px 0 0;
  color: var(--home-muted);
  line-height: 1.65;
}

.closing-cta {
  margin-top: 112px;
  margin-bottom: 94px;
  padding: 48px 54px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 40px;
  border: 1px solid var(--home-line);
  border-radius: var(--home-radius);
  background: var(--home-surface);
}

.closing-cta h2 {
  max-width: 740px;
  font-size: clamp(34px, 4.6vw, 58px);
}

.site-footer {
  width: min(1184px, calc(100% - 56px));
  margin: 0 auto;
  padding: 38px 0 52px;
  display: grid;
  grid-template-columns: auto 1fr auto;
  align-items: center;
  gap: 38px;
  border-top: 1px solid var(--home-line);
  color: var(--home-muted);
  font-size: 12px;
  line-height: 1.65;
}

.footer-brand .brand-mark {
  width: 36px;
  height: 36px;
  border-radius: 10px;
  font-size: 18px;
}

.footer-brand .brand-name strong {
  color: var(--home-ink);
  font-size: 17px;
}

.site-footer p {
  max-width: 600px;
  margin: 0;
}

.footer-links {
  display: flex;
  gap: 18px;
  white-space: nowrap;
}

@media (prefers-color-scheme: dark) {
  :root {
    --home-bg: #121311;
    --home-surface: #1c1e1a;
    --home-surface-strong: #252821;
    --home-ink: #f2f3ef;
    --home-muted: #a6aaa1;
    --home-line: rgba(242, 243, 239, 0.14);
    --home-accent: #e25b51;
    --home-accent-dark: #c8473e;
    --home-accent-soft: #4b2a27;
    --home-shadow: rgba(0, 0, 0, 0.34);
  }
}

@media (max-width: 980px) {
  .site-header {
    width: min(100% - 40px, 900px);
    grid-template-columns: 1fr auto;
  }

  .site-header nav {
    display: none;
  }

  .hero {
    width: min(100% - 40px, 900px);
    min-height: auto;
    padding: 44px 0 92px;
    grid-template-columns: 1fr;
    gap: 44px;
  }

  .hero h1 {
    max-width: 820px;
    font-size: clamp(52px, 10vw, 76px);
  }

  .hero-visual {
    min-height: 560px;
    grid-template-columns: minmax(0, 1fr) minmax(190px, 0.48fr);
  }

  .hero-visual figure {
    height: 560px;
  }

  .promise,
  .featured,
  .all-tests,
  .method,
  .standards,
  .closing-cta,
  .site-footer {
    width: min(100% - 40px, 900px);
  }

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

  .promise p:nth-child(2) {
    border-right: 0;
  }

  .promise p:nth-child(-n + 2) {
    border-bottom: 1px solid var(--home-line);
  }

  .featured-grid {
    grid-template-columns: 1fr;
    grid-template-rows: 560px 280px 280px;
  }

  .featured-main {
    grid-row: auto;
  }

  .method {
    grid-template-columns: 1fr;
    gap: 44px;
  }

  .method-intro {
    position: static;
  }

  .standards {
    grid-template-columns: 1fr;
    gap: 48px;
    padding: 52px;
  }

  .site-footer {
    grid-template-columns: 1fr;
    gap: 20px;
  }

  .footer-links {
    justify-self: start;
  }
}

@media (max-width: 680px) {
  .site-header {
    width: calc(100% - 32px);
    min-height: 64px;
  }

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

  .brand-name strong {
    font-size: 18px;
  }

  .brand-name small {
    display: none;
  }

  .header-cta {
    min-height: 38px;
    padding: 0 15px;
    font-size: 13px;
  }

  .hero {
    width: calc(100% - 32px);
    padding: 24px 0 76px;
    gap: 36px;
  }

  .hero-kicker {
    margin-bottom: 13px;
    font-size: 11px;
  }

  .hero h1 {
    font-size: clamp(43px, 13vw, 58px);
    line-height: 1;
  }

  .hero-intro {
    margin-top: 21px;
    font-size: 16px;
  }

  .hero-actions {
    display: grid;
    grid-template-columns: 1fr 1fr;
  }

  .hero-visual {
    min-height: 480px;
    grid-template-columns: 1fr;
  }

  .hero-visual figure {
    height: 480px;
  }

  .hero-visual-copy {
    padding: 20px 0 0;
  }

  .hero-visual-copy strong {
    font-size: 22px;
  }

  .promise,
  .featured,
  .all-tests,
  .method,
  .standards,
  .closing-cta,
  .site-footer {
    width: calc(100% - 32px);
  }

  .promise {
    margin-bottom: 94px;
    grid-template-columns: 1fr;
  }

  .promise p {
    border-right: 0;
    border-bottom: 1px solid var(--home-line);
  }

  .promise p:last-child {
    border-bottom: 0;
  }

  .featured,
  .all-tests,
  .method {
    padding-bottom: 96px;
  }

  .section-heading {
    margin-bottom: 28px;
  }

  .section-heading h2,
  .method-intro h2,
  .standards h2,
  .closing-cta h2 {
    font-size: 38px;
  }

  .featured-grid {
    grid-template-rows: auto auto auto;
  }

  .featured-main,
  .featured-side {
    grid-template-columns: 1fr;
  }

  .featured-main img {
    height: 430px;
  }

  .featured-side img {
    height: 240px;
  }

  .featured-main .featured-copy,
  .featured-side .featured-copy {
    padding: 26px;
  }

  .test-list {
    grid-template-columns: 1fr;
  }

  .test-list a {
    min-height: 112px;
    grid-template-columns: 68px minmax(0, 1fr) auto;
    gap: 13px;
  }

  .test-list img {
    width: 68px;
    height: 88px;
  }

  .method-list li {
    min-height: 118px;
    grid-template-columns: 1fr;
    gap: 9px;
  }

  .method-list strong {
    font-size: 21px;
  }

  .standards {
    padding: 34px 25px;
    gap: 38px;
  }

  .closing-cta {
    margin-top: 80px;
    margin-bottom: 70px;
    padding: 34px 25px;
    align-items: stretch;
    flex-direction: column;
  }

  .closing-cta .button {
    width: 100%;
  }
}

@media (prefers-reduced-motion: no-preference) {
  .hero-copy {
    animation: home-reveal 680ms cubic-bezier(0.16, 1, 0.3, 1) both;
  }

  .hero-visual {
    animation: home-reveal 760ms 90ms cubic-bezier(0.16, 1, 0.3, 1) both;
  }

  @keyframes home-reveal {
    from {
      opacity: 0;
      transform: translateY(22px);
    }
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}