:root {
  --paper: #f5f2ea;
  --cream: #eee9df;
  --ink: #10100f;
  --muted: #6f6b63;
  --line: #d9d3c8;
  --green: #1f5d40;
  --accent: #f7f56a;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  color: var(--ink);
  background: #fff;
  font-family: "Helvetica Neue", Arial, sans-serif;
  letter-spacing: 0;
}

.zh-page {
  font-family: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
}

.zh-page .hero h1,
.zh-page h2 {
  letter-spacing: 0.02em;
}

.zh-page .hero-copy {
  max-width: 680px;
}

.zh-page .hero h1 {
  white-space: nowrap;
}

.zh-page .hero-copy p,
.zh-page .intro p,
.zh-page .feature p,
.zh-page .contact-block p {
  line-height: 1.72;
}

.zh-page .impact-grid p {
  font-size: 18px;
  line-height: 1.45;
  text-transform: none;
}

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

button,
input {
  font: inherit;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  background: #fff;
  border-bottom: 1px solid var(--line);
}

.topbar {
  display: grid;
  grid-template-columns: 220px 1fr 150px;
  align-items: center;
  min-height: 62px;
  padding: 0 6.2vw;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-size: 23px;
  letter-spacing: 0.18em;
  white-space: nowrap;
}

.mark {
  width: 24px;
  height: 24px;
  border: 2px solid var(--ink);
  border-radius: 50%;
  position: relative;
}

.mark::after {
  content: "";
  position: absolute;
  left: 8px;
  top: -5px;
  width: 6px;
  height: 10px;
  border: 2px solid var(--ink);
  border-bottom: 0;
  border-radius: 8px 8px 0 0;
  transform: rotate(-30deg);
  background: #fff;
}

.primary-nav,
.category-nav {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 34px;
  font-size: 14px;
}

.primary-nav a,
.category-nav a {
  white-space: nowrap;
}

.primary-nav a::after {
  content: "⌄";
  margin-left: 7px;
  color: var(--muted);
}

.primary-nav a:nth-last-child(-n + 2)::after {
  content: "";
  margin: 0;
}

.header-icons {
  display: flex;
  justify-content: flex-end;
  gap: 18px;
}

.header-icons button {
  width: 25px;
  height: 25px;
  padding: 0;
  border: 0;
  background: transparent;
  font-size: 23px;
  line-height: 1;
  cursor: pointer;
}

.category-nav {
  min-height: 47px;
  border-top: 1px solid #eee9df;
  font-weight: 600;
  color: #111;
}

.hero {
  position: relative;
  min-height: 534px;
  overflow: hidden;
  background: var(--cream);
}

.hero-image {
  position: absolute;
  inset: 0 0 0 30%;
  width: 70%;
  height: 100%;
  object-fit: cover;
}

.hero-fade {
  position: absolute;
  inset: 0;
  background: linear-gradient(95deg, var(--cream) 34%, rgba(238, 233, 223, 0.86) 42%, rgba(255, 255, 255, 0) 57%);
}

.hero-copy {
  position: relative;
  max-width: 540px;
  padding: 138px 0 0 6.4vw;
}

.hero h1 {
  margin: 0 0 34px;
  line-height: 0.98;
  font-weight: 200;
  font-size: clamp(64px, 8vw, 112px);
}

.hero h1 strong,
.hero h1 span {
  display: block;
}

.hero h1 strong {
  font-weight: 800;
}

.hero h1 span {
  font-weight: 200;
}

.hero-copy p {
  max-width: 500px;
  margin: 0;
  font-size: 24px;
  line-height: 1.45;
}

.cert-badge {
  position: absolute;
  top: 48px;
  right: 7vw;
  display: grid;
  grid-template-columns: 64px 160px;
  align-items: center;
  gap: 10px;
  max-width: 245px;
  font-size: 11px;
  font-weight: 700;
}

.cert-badge strong {
  grid-row: 1 / 3;
  display: grid;
  place-items: center;
  width: 64px;
  height: 64px;
  border: 4px solid var(--ink);
  border-radius: 50%;
  font-size: 44px;
  line-height: 1;
}

.cert-badge span {
  align-self: end;
}

.cert-badge small {
  border-bottom: 4px solid var(--ink);
  padding-bottom: 12px;
  font-size: 10px;
  line-height: 1.15;
}

.section-pad {
  padding: 74px 6.4vw;
}

.intro {
  max-width: 960px;
}

h2 {
  margin: 0;
  font-size: clamp(34px, 4.5vw, 58px);
  line-height: 1.05;
  font-weight: 800;
}

.intro p {
  margin: 28px 0 0;
  max-width: 850px;
  font-size: 20px;
  line-height: 1.6;
}

.impact-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 0;
  margin: 58px 0 28px;
  border-top: 1px solid var(--line);
}

.impact-grid article {
  display: grid;
  grid-template-columns: 58px 1fr;
  gap: 20px;
  min-height: 196px;
  padding: 38px 36px 36px 0;
  border-bottom: 1px solid var(--line);
}

.impact-icon {
  display: grid;
  place-items: center;
  width: 32px;
  height: 32px;
  margin-top: 8px;
  color: var(--green);
  font-size: 31px;
}

.impact-grid strong {
  display: block;
  margin-bottom: 14px;
  font-size: clamp(48px, 6vw, 86px);
  line-height: 0.95;
  font-weight: 800;
}

.impact-grid p {
  margin: 0;
  text-transform: uppercase;
  font-size: 16px;
  font-weight: 700;
  line-height: 1.25;
}

.text-link {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  border-bottom: 1px solid var(--ink);
  font-weight: 700;
}

.feature {
  display: grid;
  grid-template-columns: minmax(260px, 420px) minmax(0, 1fr);
  align-items: center;
  gap: 68px;
  background: var(--paper);
}

.feature p {
  font-size: 20px;
  line-height: 1.65;
}

.feature figure {
  margin: 0;
}

.feature img {
  display: block;
  width: 100%;
  aspect-ratio: 16 / 9;
  object-fit: cover;
}

.feature figcaption {
  margin-top: 14px;
  color: var(--muted);
  font-size: 14px;
}

.faq {
  display: grid;
  grid-template-columns: 360px minmax(0, 1fr);
  gap: 72px;
}

.faq h2 span {
  display: block;
  font-weight: 300;
}

.faq-list {
  border-top: 1px solid var(--line);
}

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

summary {
  list-style: none;
  cursor: pointer;
  padding: 26px 0;
  font-size: 22px;
  font-weight: 700;
}

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

summary::after {
  content: "+";
  float: right;
  font-size: 28px;
  font-weight: 300;
}

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

details p {
  margin: -4px 0 28px;
  max-width: 760px;
  color: #2f2e2b;
  font-size: 17px;
  line-height: 1.7;
}

.story {
  background: var(--paper);
}

.story-heading h2 span {
  display: block;
  font-weight: 300;
}

.timeline {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 70px 54px;
  margin-top: 54px;
}

.timeline article {
  display: grid;
  grid-template-columns: 180px 1fr;
  gap: 24px;
  align-items: center;
}

.timeline img {
  width: 180px;
  height: 132px;
  object-fit: cover;
}

.timeline strong {
  display: block;
  margin-bottom: 12px;
  font-size: 24px;
}

.timeline p {
  margin: 0;
  color: #403e39;
  line-height: 1.55;
}

.contact-block {
  display: grid;
  grid-template-columns: 46% 1fr;
  min-height: 430px;
  background: #e8e2d5;
}

.contact-block img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.contact-block div {
  display: flex;
  flex-direction: column;
  justify-content: center;
  padding: 66px 7vw;
}

.contact-block h2 {
  max-width: 660px;
  font-size: clamp(32px, 4vw, 54px);
}

.contact-block h3 {
  margin: 26px 0 10px;
  font-size: 22px;
}

.contact-block p {
  max-width: 650px;
  font-size: 18px;
  line-height: 1.65;
}

.contact-block a {
  width: max-content;
  margin-top: 20px;
  border-bottom: 1px solid var(--ink);
  font-weight: 800;
}

.newsletter {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 50px;
  align-items: center;
  padding: 64px 6.4vw;
  background: #f7f56a;
}

.newsletter h2 {
  font-size: clamp(36px, 5vw, 64px);
}

.newsletter p {
  margin: 12px 0 0;
  font-size: 19px;
}

.newsletter label {
  display: block;
  margin-bottom: 12px;
  font-weight: 700;
}

.newsletter form div {
  display: grid;
  grid-template-columns: 1fr 160px;
  border-bottom: 2px solid var(--ink);
}

.newsletter input {
  min-width: 0;
  border: 0;
  background: transparent;
  padding: 15px 0;
  outline: 0;
}

.newsletter button {
  border: 0;
  background: var(--ink);
  color: #fff;
  font-weight: 800;
  cursor: pointer;
}

.footer {
  padding: 58px 6.4vw 34px;
  background: #111;
  color: #fff;
}

.footer-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 44px;
}

.footer h3 {
  margin: 0 0 18px;
  font-size: 18px;
}

.footer a {
  display: block;
  margin: 12px 0;
  color: #d8d8d8;
  font-size: 15px;
}

.footer-bottom {
  display: flex;
  justify-content: space-between;
  gap: 20px;
  margin-top: 52px;
  padding-top: 24px;
  border-top: 1px solid #3a3a3a;
  color: #c8c8c8;
  font-size: 14px;
}

@media (max-width: 900px) {
  .topbar {
    grid-template-columns: 1fr auto;
    padding: 0 22px;
  }

  .primary-nav {
    display: none;
  }

  .category-nav {
    justify-content: flex-start;
    gap: 22px;
    overflow-x: auto;
    padding: 0 22px;
  }

  .hero {
    min-height: 680px;
  }

  .hero-image {
    inset: 230px 0 0 0;
    width: 100%;
    height: calc(100% - 230px);
  }

  .hero-fade {
    background: linear-gradient(180deg, var(--cream) 0 44%, rgba(238, 233, 223, 0) 70%);
  }

  .hero-copy {
    padding: 72px 24px 0;
  }

  .hero-copy p {
    font-size: 20px;
  }

  .cert-badge {
    top: auto;
    right: 24px;
    bottom: 26px;
    transform: scale(0.86);
    transform-origin: bottom right;
  }

  .impact-grid,
  .feature,
  .faq,
  .timeline,
  .contact-block,
  .newsletter,
  .footer-grid {
    grid-template-columns: 1fr;
  }

  .section-pad {
    padding: 56px 24px;
  }

  .feature,
  .contact-block div,
  .newsletter,
  .footer {
    padding-left: 24px;
    padding-right: 24px;
  }

  .impact-grid article {
    min-height: 0;
    padding-right: 0;
  }

  .timeline article {
    grid-template-columns: 118px 1fr;
  }

  .timeline img {
    width: 118px;
    height: 94px;
  }

  .newsletter form div {
    grid-template-columns: 1fr;
    border-bottom: 0;
    gap: 12px;
  }

  .newsletter input {
    border-bottom: 2px solid var(--ink);
  }

  .newsletter button {
    min-height: 48px;
  }

  .footer-bottom {
    flex-direction: column;
  }
}

@media (max-width: 520px) {
  .brand span:last-child {
    font-size: 18px;
  }

  .header-icons {
    gap: 10px;
  }

  .category-nav {
    font-size: 13px;
  }

  .hero h1 {
    font-size: 58px;
  }

  .impact-grid article {
    grid-template-columns: 42px 1fr;
    gap: 14px;
  }

  .impact-grid strong {
    font-size: 42px;
  }
}