.page-about {
  --about-rail: 232px;
  --about-heading: clamp(1.7rem, 4.4vw, 2.6rem);
  background: var(--ink-900);
  color: var(--cyan-soft);
  padding-bottom: clamp(48px, 7vw, 96px);
  overflow-x: hidden;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  padding: clamp(20px, 4vw, 40px) 0 clamp(32px, 5vw, 56px);
  background:
    radial-gradient(120% 90% at 12% 0%, rgba(53, 240, 207, 0.10), transparent 62%),
    radial-gradient(90% 70% at 100% 10%, rgba(242, 184, 75, 0.08), transparent 60%);
  border-bottom: 1px solid var(--line);
}

.page-about .about-hero__top {
  display: grid;
  gap: clamp(20px, 3vw, 36px);
  margin: clamp(20px, 3.4vw, 36px) 0 clamp(24px, 3.6vw, 40px);
}

.page-about .about-hero h1 {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(2.1rem, 7.4vw, 4.6rem);
  line-height: 1.06;
  letter-spacing: -0.015em;
  color: var(--white);
  margin: 12px 0 18px;
  max-width: 15ch;
}

.page-about .about-hero .lede {
  max-width: 56ch;
  margin: 0;
  font-size: clamp(1rem, 1.6vw, 1.125rem);
  line-height: 1.78;
  color: var(--cyan-soft);
}

.page-about .about-plate {
  margin: 0;
  display: grid;
  gap: 0;
  border-top: 1px solid var(--line-strong);
}

.page-about .about-plate__row {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 16px;
  padding: 12px 0;
  border-bottom: 1px solid var(--line);
}

.page-about .about-plate dt {
  font-size: 0.8125rem;
  letter-spacing: 0.06em;
  color: var(--sage);
}

.page-about .about-plate dd {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 0.9375rem;
  color: var(--cyan);
  white-space: nowrap;
}

.page-about .about-num {
  font-family: var(--font-mono);
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--amber);
  letter-spacing: -0.02em;
}

.page-about .about-hero__media {
  margin: 0;
}

/* ---------- 主体布局 ---------- */
.page-about .about-layout {
  display: grid;
  gap: clamp(24px, 4vw, 48px);
  padding-top: clamp(36px, 5vw, 64px);
}

.page-about .about-rail__title {
  margin: 0 0 10px;
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--sage);
}

.page-about .about-rail__index {
  list-style: none;
  margin: 0;
  padding: 0 0 6px;
  display: flex;
  gap: 8px;
  overflow-x: auto;
  scrollbar-width: thin;
}

.page-about .about-rail__index li {
  flex: 0 0 auto;
}

.page-about .about-rail__index a {
  display: inline-flex;
  align-items: baseline;
  gap: 8px;
  padding: 7px 12px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  color: var(--cyan-soft);
  font-size: 0.8125rem;
  text-decoration: none;
  white-space: nowrap;
  transition: border-color 200ms var(--ease), background 200ms var(--ease);
}

.page-about .about-rail__index a span {
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  color: var(--cyan);
}

.page-about .about-rail__index a:hover,
.page-about .about-rail__index a:focus-visible {
  border-color: var(--amber-line);
  background: rgba(242, 184, 75, 0.10);
}

.page-about .about-rail__note {
  margin: 14px 0 0;
  font-size: 0.8125rem;
  line-height: 1.7;
  color: var(--sage);
  border-left: 2px solid var(--line-strong);
  padding-left: 12px;
}

/* ---------- 章节 ---------- */
.page-about .about-flow {
  display: grid;
  gap: clamp(40px, 6vw, 80px);
  min-width: 0;
}

.page-about .about-section {
  min-width: 0;
  scroll-margin-top: calc(var(--header-h) + 24px);
}

.page-about .about-section h2 {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: var(--about-heading);
  line-height: 1.14;
  letter-spacing: -0.01em;
  color: var(--white);
  margin: 10px 0 20px;
  max-width: 22ch;
}

.page-about .about-copy {
  margin: 0 0 18px;
  font-size: 1rem;
  line-height: 1.8;
  color: var(--cyan-soft);
  max-width: 62ch;
}

.page-about .about-copy--tail {
  margin-top: 22px;
  padding-top: 18px;
  border-top: 1px solid var(--line);
  font-size: 0.9375rem;
  color: var(--sage);
}

.page-about .about-section p a {
  color: var(--cyan);
  text-decoration: underline;
  text-underline-offset: 3px;
}

.page-about .about-section p a:hover,
.page-about .about-section p a:focus-visible {
  color: var(--amber);
}

.page-about .about-columns {
  display: grid;
  gap: clamp(20px, 3vw, 32px);
}

.page-about .about-columns__wide p {
  margin: 0 0 16px;
  font-size: 1rem;
  line-height: 1.8;
  color: var(--cyan-soft);
}

.page-about .about-columns__narrow {
  border-top: 1px solid var(--line-strong);
  padding-top: 16px;
}

.page-about .about-checklist {
  list-style: none;
  margin: 12px 0 14px;
  padding: 0;
  display: grid;
  gap: 10px;
}

.page-about .about-checklist li {
  position: relative;
  padding-left: 20px;
  font-size: 0.9375rem;
  line-height: 1.65;
  color: var(--cyan-soft);
}

.page-about .about-checklist li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.55em;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--cyan);
  box-shadow: 0 0 10px rgba(53, 240, 207, 0.7);
}

.page-about .about-side-note {
  margin: 0;
  font-size: 0.8125rem;
  line-height: 1.7;
  color: var(--sage);
}

/* ---------- 内容方法：反白阅读区 ---------- */
.page-about .about-section--cream {
  background: var(--cream);
  color: var(--brown);
  border-radius: var(--radius);
  padding: clamp(24px, 4.2vw, 44px);
  box-shadow: var(--shadow-soft);
}

.page-about .about-section--cream h2 {
  color: var(--brown);
}

.page-about .about-section--cream .eyebrow {
  color: #7a5a1f;
}

.page-about .about-section--cream .about-copy {
  color: #3b332a;
}

.page-about .about-section--cream .about-copy--tail {
  color: #5a4f42;
  border-top-color: rgba(26, 21, 18, 0.16);
}

.page-about .about-section--cream p a {
  color: #8a4a12;
}

.page-about .about-methods {
  list-style: none;
  margin: 24px 0 0;
  padding: 0;
  display: grid;
  gap: 0;
  border-top: 1px solid rgba(26, 21, 18, 0.18);
}

.page-about .about-method {
  display: grid;
  grid-template-columns: 46px minmax(0, 1fr);
  gap: 4px 12px;
  padding: 18px 0;
  border-bottom: 1px solid rgba(26, 21, 18, 0.14);
}

.page-about .about-method__no {
  grid-row: span 2;
  font-family: var(--font-mono);
  font-size: 0.875rem;
  font-weight: 700;
  color: #b07a1c;
  padding-top: 4px;
}

.page-about .about-method h3 {
  margin: 0;
  font-size: 1.0625rem;
  font-weight: 700;
  letter-spacing: 0.01em;
  color: var(--brown);
}

.page-about .about-method p {
  margin: 4px 0 0;
  font-size: 0.9375rem;
  line-height: 1.72;
  color: #3b332a;
  max-width: 58ch;
}

/* ---------- 团队 ---------- */
.page-about .about-team {
  display: grid;
  gap: clamp(18px, 3vw, 30px);
  margin-bottom: 24px;
}

.page-about .about-team__media {
  margin: 0;
}

.page-about .about-team__text p {
  margin: 0 0 14px;
  font-size: 1rem;
  line-height: 1.8;
  color: var(--cyan-soft);
}

.page-about .about-team__plates {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  margin-bottom: 22px;
}

.page-about .about-mini-plate {
  background: var(--ink-800);
  padding: 16px 14px;
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.page-about .about-mini-plate span:last-child {
  font-size: 0.75rem;
  letter-spacing: 0.05em;
  color: var(--sage);
  line-height: 1.5;
}

/* ---------- 时间轴 ---------- */
.page-about .about-timeline {
  list-style: none;
  margin: 26px 0 0;
  padding: 0;
  position: relative;
}

.page-about .about-timeline::before {
  content: "";
  position: absolute;
  left: 7px;
  top: 8px;
  bottom: 8px;
  width: 1px;
  background: linear-gradient(180deg, var(--cyan), rgba(53, 240, 207, 0.12));
}

.page-about .about-timeline__item {
  position: relative;
  padding: 0 0 26px 32px;
}

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

.page-about .about-timeline__marker {
  position: absolute;
  left: 0;
  top: 4px;
  width: 15px;
  height: 15px;
  border-radius: 50%;
  border: 1px solid var(--cyan);
  background: var(--ink-900);
  display: grid;
  place-items: center;
}

.page-about .about-timeline__marker::after {
  content: "";
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: var(--cyan);
}

.page-about .about-timeline__time {
  position: absolute;
  left: 24px;
  top: -2px;
  display: none;
}

.page-about .about-timeline__body h3 {
  margin: 0 0 6px;
  font-family: var(--font-mono);
  font-size: 1rem;
  font-weight: 700;
  letter-spacing: 0.02em;
  color: var(--amber);
}

.page-about .about-timeline__body p {
  margin: 0;
  font-size: 0.9375rem;
  line-height: 1.75;
  color: var(--cyan-soft);
  max-width: 58ch;
}

.page-about .about-details {
  margin-top: 12px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--ink-800);
}

.page-about .about-details summary {
  cursor: pointer;
  padding: 10px 14px;
  font-size: 0.8125rem;
  letter-spacing: 0.04em;
  color: var(--cyan);
  list-style: none;
  display: flex;
  align-items: center;
  gap: 8px;
}

.page-about .about-details summary::-webkit-details-marker {
  display: none;
}

.page-about .about-details summary::before {
  content: "+";
  font-family: var(--font-mono);
  color: var(--amber);
}

.page-about .about-details[open] summary::before {
  content: "–";
}

.page-about .about-details ul {
  margin: 0;
  padding: 0 16px 14px 30px;
  display: grid;
  gap: 8px;
}

.page-about .about-details li {
  font-size: 0.875rem;
  line-height: 1.7;
  color: var(--sage);
}

/* ---------- 合作生态 ---------- */
.page-about .about-eco {
  display: grid;
  gap: clamp(20px, 3vw, 32px);
}

.page-about .about-eco__text p {
  margin: 0 0 16px;
  font-size: 1rem;
  line-height: 1.8;
  color: var(--cyan-soft);
}

.page-about .about-eco__list {
  list-style: none;
  margin: 0 0 22px;
  padding: 0;
  display: grid;
  gap: 12px;
}

.page-about .about-eco__list li {
  padding: 12px 14px;
  border-left: 2px solid var(--line-strong);
  background: var(--ink-800);
  font-size: 0.9375rem;
  line-height: 1.72;
  color: var(--cyan-soft);
}

.page-about .about-eco__list strong {
  color: var(--white);
  font-weight: 700;
}

.page-about .about-honor {
  border-top: 1px solid var(--amber-line);
  padding-top: 16px;
}

.page-about .about-honor p:last-child {
  margin: 10px 0 0;
  font-size: 0.9375rem;
  line-height: 1.75;
  color: var(--cyan-soft);
}

.page-about .about-eco__media {
  margin: 0;
  align-self: start;
}

/* ---------- 收束区 ---------- */
.page-about .about-section--next {
  border-top: 1px solid var(--line-strong);
  padding-top: clamp(28px, 4vw, 48px);
}

.page-about .about-next {
  display: grid;
  gap: clamp(22px, 3.4vw, 34px);
}

.page-about .about-next__steps {
  list-style: none;
  margin: 0;
  padding: 0;
  counter-reset: nextstep;
  display: grid;
  gap: 18px;
}

.page-about .about-next__steps li {
  counter-increment: nextstep;
  position: relative;
  padding-left: 34px;
}

.page-about .about-next__steps li::before {
  content: "0" counter(nextstep);
  position: absolute;
  left: 0;
  top: 2px;
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  color: var(--cyan);
}

.page-about .about-next__steps h3 {
  margin: 0 0 6px;
  font-size: 1.0625rem;
  color: var(--white);
}

.page-about .about-next__steps p {
  margin: 0;
  font-size: 0.9375rem;
  line-height: 1.75;
  color: var(--cyan-soft);
}

.page-about .about-contact-card {
  background: var(--ink-800);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: clamp(20px, 3vw, 28px);
}

.page-about .about-contact-card__title {
  margin: 0 0 14px;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--amber);
}

.page-about .about-contact-card ul {
  list-style: none;
  margin: 0 0 14px;
  padding: 0;
  display: grid;
  gap: 10px;
}

.page-about .about-contact-card li {
  display: grid;
  grid-template-columns: 4.5em minmax(0, 1fr);
  gap: 10px;
  font-size: 0.9375rem;
  line-height: 1.6;
  color: var(--cyan-soft);
  word-break: break-word;
}

.page-about .about-contact-card li span {
  color: var(--sage);
  font-size: 0.8125rem;
  letter-spacing: 0.04em;
}

.page-about .about-contact-card a {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid var(--line-strong);
}

.page-about .about-contact-card a:hover,
.page-about .about-contact-card a:focus-visible {
  color: var(--amber);
  border-bottom-color: var(--amber-line);
}

.page-about .about-contact-card__note {
  margin: 0 0 18px;
  font-size: 0.8125rem;
  line-height: 1.7;
  color: var(--sage);
}

.page-about .about-contact-card__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin: 0;
}

/* ---------- 平板 ---------- */
@media (min-width: 640px) {
  .page-about .about-team__plates {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .about-hero__top {
    grid-template-columns: minmax(0, 1.45fr) minmax(0, 1fr);
    align-items: end;
  }
}

/* ---------- 桌面 ---------- */
@media (min-width: 960px) {
  .page-about .about-layout {
    grid-template-columns: var(--about-rail) minmax(0, 1fr);
    align-items: start;
  }

  .page-about .about-rail {
    position: sticky;
    top: calc(var(--header-h) + 28px);
    border-right: 1px solid var(--line);
    padding-right: 24px;
  }

  .page-about .about-rail__index {
    display: grid;
    gap: 2px;
    overflow: visible;
    padding-bottom: 0;
  }

  .page-about .about-rail__index a {
    display: flex;
    white-space: normal;
    border: 0;
    border-left: 2px solid transparent;
    border-radius: 0;
    padding: 9px 10px;
    font-size: 0.875rem;
    line-height: 1.5;
  }

  .page-about .about-rail__index a:hover,
  .page-about .about-rail__index a:focus-visible {
    border-left-color: var(--amber);
    background: rgba(53, 240, 207, 0.06);
  }

  .page-about .about-columns {
    grid-template-columns: minmax(0, 1fr) 260px;
    gap: clamp(28px, 3.4vw, 44px);
    align-items: start;
  }

  .page-about .about-columns__narrow {
    border-top: 0;
    border-left: 1px solid var(--line);
    padding: 4px 0 0 24px;
  }

  .page-about .about-team {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, 1fr);
    align-items: start;
  }

  .page-about .about-eco {
    grid-template-columns: minmax(0, 1fr) 320px;
    align-items: start;
  }

  .page-about .about-next {
    grid-template-columns: minmax(0, 1fr) 360px;
    align-items: start;
  }

  .page-about .about-timeline__item {
    padding-left: 0;
    display: grid;
    grid-template-columns: 92px minmax(0, 1fr);
    gap: 0 28px;
    padding-bottom: 30px;
  }

  .page-about .about-timeline::before {
    left: 96px;
  }

  .page-about .about-timeline__marker {
    left: 89px;
  }

  .page-about .about-timeline__time {
    display: block;
    position: static;
    grid-column: 1;
    font-family: var(--font-mono);
    font-size: 0.875rem;
    font-weight: 700;
    letter-spacing: 0.02em;
    color: var(--amber);
    text-align: right;
    padding-top: 1px;
  }

  .page-about .about-timeline__body {
    grid-column: 2;
  }

  .page-about .about-timeline__body h3 {
    font-family: var(--font-body);
    font-size: 1.0625rem;
    color: var(--white);
  }
}

/* ---------- 大屏 ---------- */
@media (min-width: 1200px) {
  .page-about .about-section--cream {
    margin-right: -24px;
  }

  .page-about .about-hero h1 {
    max-width: 16ch;
  }
}

/* ---------- 动效 ---------- */
.page-about .js-motion .about-timeline__item[data-reveal] {
  opacity: 0;
  transform: translateY(14px);
  transition: opacity 520ms var(--ease), transform 520ms var(--ease);
}

.page-about .js-motion .about-timeline__item[data-reveal].is-visible {
  opacity: 1;
  transform: none;
}

@media (prefers-reduced-motion: reduce) {
  .page-about .js-motion .about-timeline__item[data-reveal] {
    opacity: 1;
    transform: none;
    transition: none;
  }

  .page-about .about-plate dd,
  .page-about .about-mini-plate {
    transition: none;
  }
}