.page-about {
  --about-gap: clamp(1rem, 2.5vw, 2rem);
  --about-line: rgba(11, 59, 60, .16);
  --about-line-light: rgba(243, 237, 226, .22);
  --about-axis-w: 12.5rem;
  display: block;
  background: var(--paper-100);
  color: var(--ink-900);
}

.page-about .about-topline {
  padding-top: clamp(1rem, 2.5vw, 1.75rem);
}

.page-about .about-hero {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(1.5rem, 4vw, 2.75rem);
  align-items: end;
  padding-block: clamp(.5rem, 2vw, 1.5rem) clamp(1rem, 3vw, 2rem);
}

.page-about .about-hero-copy h1 {
  margin: .35rem 0 .75rem;
  font-family: var(--font-head);
  font-size: clamp(2.1rem, 7vw, 4.1rem);
  line-height: 1.05;
  letter-spacing: -.01em;
  text-wrap: balance;
}

.page-about .about-hero-copy .lead {
  max-width: 46ch;
  color: var(--ink-900);
}

.page-about .about-hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: .75rem;
  margin-top: 1.5rem;
}

.page-about .about-hero-visual {
  position: relative;
  margin: 0;
  isolation: isolate;
}

.page-about .about-hero-visual::after {
  content: "";
  position: absolute;
  z-index: -1;
  inset: 12% 0 0 14%;
  background: var(--teal-900);
  background-image: var(--grain-dark);
  border-radius: var(--radius-lg);
}

.page-about .media-frame img {
  width: 100%;
  max-width: 100%;
  height: auto;
  object-fit: cover;
  display: block;
}

.page-about .about-standards,
.page-about .about-crew,
.page-about .about-legacy {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(1.5rem, 4vw, 3rem);
  align-items: start;
}

.page-about .about-section-head {
  max-width: 62ch;
  margin-bottom: clamp(1.5rem, 4vw, 2.5rem);
}

.page-about .about-section-head h2 {
  margin: .4rem 0 .75rem;
  font-family: var(--font-head);
  font-size: clamp(1.6rem, 4.2vw, 2.4rem);
  line-height: 1.18;
  letter-spacing: -.01em;
}

.page-about .about-section-lead {
  color: var(--ink-500);
  margin: 0;
}

.page-about .about-section-head--dark .about-section-lead {
  color: rgba(243, 237, 226, .78);
}

.page-about .about-eyebrow-dark {
  color: var(--orange-300);
}

.page-about .about-section-dark {
  background: var(--teal-900);
  background-image: var(--grain-dark);
  color: var(--paper-100);
}

.page-about .about-section-dark h2,
.page-about .about-section-dark h3 {
  color: var(--paper-100);
}

/* ---------- 时间轴 ---------- */
.page-about .about-timeline {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(1.5rem, 4vw, 3rem);
}

.page-about .about-axis {
  display: none;
}

.page-about .about-stages {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: clamp(1rem, 2.5vw, 1.5rem);
}

.page-about .about-stage {
  position: relative;
  padding: clamp(1rem, 2.5vw, 1.5rem) clamp(1rem, 2.5vw, 1.75rem);
  background: var(--paper-100);
  border: var(--hair);
  border-left: 4px solid var(--teal-700);
  border-radius: var(--radius-md);
  scroll-margin-top: calc(var(--strip-h) + 1.5rem);
}

.page-about .about-stage:target {
  border-left-color: var(--orange-500);
  background: var(--paper-200);
}

.page-about .about-stage-head {
  display: flex;
  align-items: baseline;
  gap: .65rem;
  margin-bottom: .5rem;
}

.page-about .about-stage-num {
  font-size: .8125rem;
  letter-spacing: .08em;
  color: var(--orange-500);
  font-weight: 700;
}

.page-about .about-stage-head h3 {
  margin: 0;
  font-family: var(--font-head);
  font-size: clamp(1.05rem, 2.4vw, 1.3rem);
  line-height: 1.3;
}

.page-about .about-stage p {
  margin: 0;
  color: var(--ink-500);
  max-width: 68ch;
}

/* ---------- 三条标准 ---------- */
.page-about .about-rules {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: clamp(1rem, 2.5vw, 1.5rem);
}

.page-about .about-rule {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: clamp(.85rem, 2.5vw, 1.5rem);
  padding-bottom: clamp(1rem, 2.5vw, 1.5rem);
  border-bottom: 1px dashed var(--about-line);
}

.page-about .about-rule:last-child {
  border-bottom: 0;
  padding-bottom: 0;
}

.page-about .about-rule-num {
  font-size: clamp(1.25rem, 3vw, 1.75rem);
  line-height: 1;
  font-weight: 700;
  color: var(--orange-500);
  padding-top: .15rem;
}

.page-about .about-rule-body h3 {
  margin: 0 0 .5rem;
  font-family: var(--font-head);
  font-size: clamp(1.1rem, 2.6vw, 1.4rem);
  line-height: 1.3;
}

.page-about .about-rule-body p {
  margin: 0 0 .6rem;
  color: var(--ink-500);
  max-width: 64ch;
}

.page-about .about-rule-eg {
  display: inline-block;
  margin: 0;
  padding: .4rem .85rem;
  background: var(--paper-200);
  border-left: 3px solid var(--orange-300);
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  font-family: var(--font-mono);
  font-size: .8125rem;
  color: var(--ink-900);
}

.page-about .about-rule-eg .mono {
  color: var(--teal-700);
  margin-right: .5rem;
  letter-spacing: .08em;
}

/* ---------- 团队 ---------- */
.page-about .about-crew-cols {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: clamp(1rem, 2.5vw, 1.5rem);
}

.page-about .about-crew-col {
  position: relative;
  padding: clamp(1rem, 2.5vw, 1.5rem);
  border: 1px solid var(--about-line-light);
  border-radius: var(--radius-md);
  background: rgba(243, 237, 226, .05);
}

.page-about .about-crew-tag {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 2rem;
  height: 2rem;
  border-radius: var(--radius-pill);
  background: var(--orange-500);
  color: #fff;
  font-weight: 700;
  font-size: .875rem;
  margin-bottom: .75rem;
}

.page-about .about-crew-col h3 {
  margin: 0 0 .5rem;
  font-family: var(--font-head);
  font-size: clamp(1.05rem, 2.4vw, 1.3rem);
}

.page-about .about-crew-col p {
  margin: 0;
  color: rgba(243, 237, 226, .78);
  max-width: 44ch;
}

.page-about .about-crew-figure {
  margin: 0;
}

.page-about .about-crew-figure .media-caption {
  color: rgba(243, 237, 226, .7);
}

/* ---------- 旧版结构 ---------- */
.page-about .about-legacy-tabs {
  min-width: 0;
}

.page-about .about-diff-list {
  margin: 0;
  padding-left: 1.15rem;
  display: grid;
  gap: .65rem;
}

.page-about .about-diff-list li {
  color: var(--ink-500);
  line-height: 1.7;
}

.page-about .about-diff-list li::marker {
  color: var(--orange-500);
}

.page-about .about-legacy-figure {
  margin: 0;
}

.page-about .about-legacy-note {
  margin: clamp(1.5rem, 4vw, 2.25rem) 0 0;
  padding: clamp(1rem, 2.5vw, 1.35rem) clamp(1rem, 2.5vw, 1.5rem);
  background: var(--paper-200);
  border-radius: var(--radius-md);
  border-left: 4px solid var(--teal-700);
  color: var(--ink-900);
}

.page-about .about-legacy-note a {
  color: var(--teal-700);
  text-decoration: underline;
  text-underline-offset: 3px;
}

/* ---------- 合作机构 ---------- */
.page-about .about-partners {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: .75rem;
}

.page-about .about-partner {
  padding: clamp(.9rem, 2vw, 1.15rem) clamp(1rem, 2.5vw, 1.35rem);
  border: var(--hair);
  border-radius: var(--radius-md);
  background: var(--paper-200);
  transition: transform .18s ease, border-color .18s ease;
}

.page-about .about-partner:hover,
.page-about .about-partner:focus-visible {
  transform: translateY(-2px);
  border-color: var(--teal-700);
  outline: none;
}

.page-about .about-partner:focus-visible {
  box-shadow: 0 0 0 3px var(--orange-300);
}

.page-about .about-partner-region {
  display: inline-block;
  padding: .15rem .6rem;
  border-radius: var(--radius-pill);
  background: var(--teal-900);
  color: var(--paper-100);
  font-size: .75rem;
  letter-spacing: .08em;
  margin-bottom: .5rem;
}

.page-about .about-partner-name {
  display: block;
  font-family: var(--font-head);
  font-size: clamp(1rem, 2.2vw, 1.15rem);
  line-height: 1.35;
  color: var(--ink-900);
}

.page-about .about-partner-note {
  margin: .5rem 0 0;
  color: var(--ink-500);
  font-size: .9375rem;
  line-height: 1.7;
}

/* ---------- 我们在意什么 ---------- */
.page-about .about-pledge {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(1rem, 2.5vw, 1.5rem);
}

.page-about .about-pledge-item {
  padding: clamp(1.1rem, 2.5vw, 1.6rem);
  background: var(--paper-100);
  border: var(--hair);
  border-radius: var(--radius-md);
}

.page-about .about-pledge-item h3 {
  margin: 0 0 .55rem;
  font-family: var(--font-head);
  font-size: clamp(1.05rem, 2.4vw, 1.25rem);
  line-height: 1.3;
}

.page-about .about-pledge-item p {
  margin: 0;
  color: var(--ink-500);
  max-width: 46ch;
}

.page-about .about-pledge-item a {
  color: var(--teal-700);
  text-decoration: underline;
  text-underline-offset: 3px;
}

.page-about .about-cta {
  margin-top: clamp(1.75rem, 4vw, 2.75rem);
  padding: clamp(1.5rem, 4vw, 2.5rem);
  border-radius: var(--radius-lg);
  background: var(--teal-900);
  background-image: var(--grain-dark);
  color: var(--paper-100);
  display: grid;
  gap: 1.25rem;
  align-items: center;
}

.page-about .about-cta-text {
  margin: 0;
  font-family: var(--font-head);
  font-size: clamp(1.1rem, 3vw, 1.55rem);
  line-height: 1.35;
}

.page-about .about-cta-actions {
  display: flex;
  flex-wrap: wrap;
  gap: .75rem;
}

@media (min-width: 48rem) {
  .page-about .about-partners {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 1rem;
  }

  .page-about .about-pledge {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .page-about .about-crew-cols {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .page-about .about-cta {
    grid-template-columns: minmax(0, 1fr) auto;
  }
}

@media (min-width: 62rem) {
  .page-about .about-hero {
    grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
    gap: clamp(2rem, 5vw, 4rem);
  }

  .page-about .about-standards,
  .page-about .about-legacy {
    grid-template-columns: minmax(0, 4fr) minmax(0, 8fr);
  }

  .page-about .about-crew {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
  }

  .page-about .about-timeline {
    grid-template-columns: var(--about-axis-w) minmax(0, 1fr);
    gap: clamp(1.5rem, 4vw, 3rem);
  }

  .page-about .about-axis {
    display: block;
    position: sticky;
    top: calc(var(--strip-h) + 1.5rem);
    align-self: start;
  }

  .page-about .about-axis-title {
    font-size: .6875rem;
    letter-spacing: .14em;
    color: var(--ink-500);
    margin: 0 0 .85rem;
  }

  .page-about .about-axis-list {
    list-style: none;
    margin: 0;
    padding: 0 0 0 .9rem;
    border-left: 2px solid var(--about-line);
    display: grid;
    gap: .1rem;
  }

  .page-about .about-axis-node {
    position: relative;
    display: flex;
    align-items: center;
    gap: .5rem;
    padding: .34rem .5rem;
    border-radius: var(--radius-pill);
    color: var(--ink-500);
    text-decoration: none;
    font-size: .875rem;
    transition: color .16s ease, background-color .16s ease;
  }

  .page-about .about-axis-node .mono {
    font-size: .75rem;
    letter-spacing: .06em;
    color: var(--teal-700);
  }

  .page-about .about-axis-node::before {
    content: "";
    position: absolute;
    left: calc(-.9rem - 6px);
    top: 50%;
    width: 10px;
    height: 10px;
    margin-top: -5px;
    border-radius: 50%;
    background: var(--paper-100);
    border: 2px solid var(--teal-700);
  }

  .page-about .about-axis-node:hover,
  .page-about .about-axis-node:focus-visible {
    background: var(--paper-200);
    color: var(--ink-900);
  }

  .page-about .about-axis-node:hover::before,
  .page-about .about-axis-node:focus-visible::before {
    background: var(--orange-500);
    border-color: var(--orange-500);
  }

  .page-about .about-stage {
    padding: clamp(1.25rem, 2.5vw, 1.75rem) clamp(1.35rem, 3vw, 2.25rem);
  }
}

@media (min-width: 78rem) {
  .page-about .about-partners {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

@media (hover: hover) {
  .page-about .about-partner-note {
    max-height: 0;
    opacity: 0;
    overflow: hidden;
    transition: max-height .22s ease, opacity .22s ease;
  }

  .page-about .about-partner:hover .about-partner-note,
  .page-about .about-partner:focus-within .about-partner-note {
    max-height: 10rem;
    opacity: 1;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-partner,
  .page-about .about-axis-node,
  .page-about .about-partner-note {
    transition: none;
  }
}
</main>