.page-about {
  background: var(--paper);
  color: var(--ink);
  overflow-x: clip;
}

.page-about .breadcrumb {
  padding-top: 26px;
  padding-bottom: 10px;
}

.page-about .breadcrumb__list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 6px;
  list-style: none;
  margin: 0;
  padding: 0;
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: .05em;
}

.page-about .breadcrumb__item + .breadcrumb__item::before {
  content: "/";
  color: var(--slate);
  margin-right: 6px;
}

.page-about .breadcrumb__link {
  color: var(--indigo);
  text-decoration: none;
  border-bottom: 1px solid transparent;
}

.page-about .breadcrumb__link:hover {
  border-bottom-color: var(--gold);
}

.page-about .breadcrumb__current {
  color: var(--slate);
}

/* ---------- hero ---------- */
.page-about .about-hero {
  padding: clamp(16px, 3vw, 34px) var(--gutter) clamp(30px, 5vw, 56px);
}

.page-about .about-hero__frame {
  position: relative;
  max-width: 1180px;
  margin: 0 auto;
  border: 1px solid var(--line);
  background:
    repeating-linear-gradient(0deg, transparent 0 3px, rgba(28, 27, 24, .016) 3px 4px),
    var(--card);
  padding: clamp(26px, 5vw, 64px) clamp(20px, 5vw, 64px) clamp(28px, 5vw, 58px);
  box-shadow: var(--shadow);
}

.page-about .about-hero__frame::before,
.page-about .about-hero__frame::after {
  content: "";
  position: absolute;
  width: 26px;
  height: 26px;
  pointer-events: none;
}

.page-about .about-hero__frame::before {
  top: -1px;
  left: -1px;
  border-top: 2px solid var(--cinnabar);
  border-left: 2px solid var(--cinnabar);
}

.page-about .about-hero__frame::after {
  right: -1px;
  bottom: -1px;
  border-right: 2px solid var(--gold);
  border-bottom: 2px solid var(--gold);
}

.page-about .about-hero__label {
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: .22em;
  color: var(--cinnabar);
  margin: 0;
}

.page-about .about-hero__title {
  font-family: var(--serif);
  font-size: clamp(30px, 5.4vw, 52px);
  line-height: 1.2;
  font-weight: 700;
  letter-spacing: -.01em;
  margin: 16px 0 20px;
  max-width: 18ch;
}

.page-about .about-hero__lede {
  font-size: clamp(15.5px, 1.6vw, 17px);
  line-height: 1.85;
  margin: 0 0 26px;
  max-width: 62ch;
}

.page-about .about-hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-bottom: 30px;
}

.page-about .about-hero__actions .btn {
  text-decoration: none;
}

.page-about .about-hero__stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px 20px;
  margin: 0;
  padding-top: 22px;
  border-top: 1px solid var(--line);
}

.page-about .about-hero__stat dt {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: .16em;
  color: var(--slate);
  margin-bottom: 4px;
}

.page-about .about-hero__stat dd {
  margin: 0;
  font-family: var(--serif);
  font-size: 22px;
  font-weight: 700;
  color: var(--indigo);
}

/* ---------- 页面内目录 ---------- */
.page-about .about-toc {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 6px 16px;
  max-width: 1180px;
  margin: 0 auto;
  padding: 14px var(--gutter);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: .06em;
}

.page-about .about-toc__label {
  color: var(--slate);
}

.page-about .about-toc__link {
  color: var(--indigo);
  text-decoration: none;
  padding: 2px 0;
  border-bottom: 1px solid transparent;
  transition: color .15s var(--ease), border-color .15s var(--ease);
}

.page-about .about-toc__link:hover,
.page-about .about-toc__link[aria-current="true"] {
  color: var(--cinnabar);
  border-bottom-color: var(--cinnabar);
}

/* ---------- 图片 ---------- */
.page-about .about-figure {
  margin: 0 auto;
  padding: 0 var(--gutter);
  max-width: 1180px;
}

.page-about .about-figure img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
  border-radius: 2px;
}

.page-about .about-figure__caption {
  font-family: var(--mono);
  font-size: 11.5px;
  letter-spacing: .04em;
  color: var(--slate);
  margin: 10px 0 0;
  line-height: 1.7;
}

.page-about .about-figure--lead {
  padding-bottom: clamp(40px, 6vw, 76px);
}

.page-about .about-figure--inline {
  padding: 0;
  margin: 28px 0 0;
}

/* ---------- 章节 ---------- */
.page-about .about-part {
  padding: clamp(46px, 7vw, 92px) 0;
  border-top: 1px solid var(--line);
}

.page-about .about-part--alt {
  background: var(--wall);
  border-top-color: rgba(28, 27, 24, .1);
  border-bottom: 1px solid rgba(28, 27, 24, .1);
}

.page-about .about-part__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 22px;
}

.page-about .about-part__side {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 10px 14px;
  padding: 0 0 12px;
  border-bottom: 1px solid var(--line);
}

.page-about .about-part__num {
  font-family: var(--mono);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: .2em;
  color: var(--cinnabar);
}

.page-about .about-part__year {
  font-family: var(--mono);
  font-size: 11.5px;
  letter-spacing: .12em;
  color: var(--gold-ink);
  padding: 1px 7px;
  border: 1px solid currentColor;
  border-radius: 2px;
}

.page-about .about-part__tag {
  font-family: var(--mono);
  font-size: 11.5px;
  letter-spacing: .1em;
  color: var(--slate);
}

.page-about .about-part__body {
  min-width: 0;
}

.page-about .about-part__title {
  font-family: var(--serif);
  font-size: clamp(24px, 3.6vw, 34px);
  line-height: 1.3;
  font-weight: 700;
  letter-spacing: -.005em;
  margin: 0 0 18px;
}

.page-about .about-part__body > p {
  font-size: 16px;
  line-height: 1.85;
  margin: 0 0 16px;
  max-width: 66ch;
}

.page-about .about-inline-link {
  color: var(--indigo);
  text-decoration: none;
  border-bottom: 1px solid var(--gold);
  padding-bottom: 1px;
}

.page-about .about-inline-link:hover {
  color: var(--cinnabar);
  border-bottom-color: var(--cinnabar);
}

.page-about .about-inline-link--light {
  color: var(--gold);
  border-bottom-color: rgba(196, 154, 74, .6);
}

.page-about .about-inline-link--light:hover {
  color: var(--paper);
  border-bottom-color: var(--paper);
}

/* ---------- 引文 ---------- */
.page-about .about-quote {
  margin: 26px 0;
  padding: 18px 20px;
  background: var(--rice);
  border-left: 3px solid var(--indigo);
  border-radius: 0 2px 2px 0;
  max-width: 56ch;
}

.page-about .about-quote p {
  margin: 0;
  font-family: var(--serif);
  font-size: clamp(16px, 1.9vw, 19px);
  line-height: 1.75;
  color: var(--indigo);
}

/* ---------- 四个栏目 ---------- */
.page-about .about-columns {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 14px;
  margin: 26px 0 34px;
}

.page-about .about-column {
  border: 1px solid var(--line);
  background: var(--card);
  border-radius: 3px;
  padding: 18px 18px 20px;
  box-shadow: var(--shadow);
  transition: border-color .15s var(--ease), transform .15s var(--ease);
}

.page-about .about-column:hover {
  border-color: var(--gold);
  transform: translateY(-1px);
}

.page-about .about-column__num {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: .22em;
  color: var(--cinnabar);
}

.page-about .about-column__name {
  font-family: var(--serif);
  font-size: 19px;
  font-weight: 700;
  margin: 6px 0 8px;
}

.page-about .about-column p {
  margin: 0;
  font-size: 14px;
  line-height: 1.78;
}

/* ---------- 选题流程 ---------- */
.page-about .about-steps__title {
  font-family: var(--serif);
  font-size: 20px;
  font-weight: 700;
  margin: 0 0 4px;
  padding-top: 22px;
  border-top: 1px solid var(--line);
}

.page-about .about-steps__list {
  list-style: none;
  margin: 12px 0 26px;
  padding: 0;
}

.page-about .about-steps__list li {
  display: grid;
  grid-template-columns: 38px minmax(0, 1fr);
  gap: 14px;
  padding: 14px 0;
  border-bottom: 1px solid var(--line-soft);
}

.page-about .about-steps__num {
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: .1em;
  color: var(--cinnabar);
  padding-top: 3px;
}

.page-about .about-steps__list strong {
  display: block;
  font-family: var(--serif);
  font-size: 16px;
  font-weight: 700;
  margin-bottom: 4px;
}

.page-about .about-steps__list p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.75;
  max-width: 60ch;
}

.page-about .about-note {
  font-size: 14.5px;
  line-height: 1.8;
  color: var(--ink);
  background: var(--rice);
  border-left: 2px solid var(--cinnabar);
  padding: 14px 16px;
  margin: 0;
  max-width: 66ch;
}

/* ---------- 图片下方展开 ---------- */
.page-about .about-details {
  margin-top: 16px;
  border: 1px solid var(--line);
  border-radius: 3px;
  background: var(--card);
}

.page-about .about-details summary {
  cursor: pointer;
  list-style: none;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 12px 16px;
  font-family: var(--mono);
  font-size: 12.5px;
  letter-spacing: .05em;
  color: var(--indigo);
}

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

.page-about .about-details summary::after {
  content: "+";
  font-family: var(--sans);
  font-size: 17px;
  line-height: 1;
  color: var(--cinnabar);
}

.page-about .about-details[open] summary::after {
  content: "−";
}

.page-about .about-details__body {
  border-top: 1px solid var(--line-soft);
  padding: 12px 16px 14px;
}

.page-about .about-details__body p {
  margin: 0;
  font-size: 14px;
  line-height: 1.78;
  max-width: 62ch;
}

/* ---------- 团队 ---------- */
.page-about .about-team {
  margin: 24px 0 18px;
  border-top: 1px solid var(--line);
}

.page-about .about-team__row {
  display: grid;
  grid-template-columns: 62px minmax(0, 1fr);
  gap: 2px 16px;
  padding: 16px 0;
  border-bottom: 1px solid var(--line-soft);
}

.page-about .about-team__num {
  font-family: var(--serif);
  font-size: 30px;
  font-weight: 700;
  line-height: 1;
  color: var(--indigo);
  grid-row: 1 / span 2;
}

.page-about .about-team__label {
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: .1em;
  color: var(--cinnabar);
  align-self: center;
}

.page-about .about-team__text {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.78;
  grid-column: 2;
}

/* ---------- 年份刻度与时间线 ---------- */
.page-about .about-years {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 20px 0 26px;
}

.page-about .about-years__item {
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: .1em;
  padding: 6px 11px;
  border: 1px solid var(--line);
  border-radius: 2px;
  background: var(--card);
  color: var(--indigo);
  text-decoration: none;
  transition: border-color .15s var(--ease), color .15s var(--ease), background .15s var(--ease);
}

.page-about .about-years__item:hover,
.page-about .about-years__item:focus-visible {
  border-color: var(--gold);
  color: var(--cinnabar);
  background: var(--paper);
}

.page-about .about-timeline {
  list-style: none;
  margin: 0;
  padding: 0 0 0 20px;
  border-left: 1px solid var(--line);
}

.page-about .about-timeline__item {
  position: relative;
  padding: 0 0 24px 14px;
  scroll-margin-top: 96px;
}

.page-about .about-timeline__item::before {
  content: "";
  position: absolute;
  left: -25px;
  top: 7px;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--paper);
  border: 2px solid var(--cinnabar);
  box-sizing: border-box;
}

.page-about .about-timeline__item:last-child {
  padding-bottom: 4px;
}

.page-about .about-timeline__item:target::before {
  background: var(--cinnabar);
  box-shadow: 0 0 0 4px rgba(179, 58, 43, .16);
}

.page-about .about-timeline__year {
  display: inline-block;
  font-family: var(--mono);
  font-size: 12.5px;
  font-weight: 700;
  letter-spacing: .14em;
  color: var(--indigo);
  margin-bottom: 8px;
  padding: 2px 0;
  border-radius: 2px;
  transition: background .15s var(--ease), color .15s var(--ease);
}

.page-about .about-timeline__item:target .about-timeline__year {
  background: var(--cinnabar);
  color: var(--paper);
  padding: 2px 9px;
}

.page-about .about-timeline__body h3 {
  font-family: var(--serif);
  font-size: 18px;
  font-weight: 700;
  margin: 0 0 6px;
}

.page-about .about-timeline__body p {
  margin: 0;
  font-size: 15px;
  line-height: 1.78;
  max-width: 62ch;
}

/* ---------- 合作生态 ---------- */
.page-about .about-partners {
  list-style: none;
  margin: 22px 0 18px;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 12px;
}

.page-about .about-partners li {
  background: var(--card);
  border: 1px solid var(--line);
  border-left: 3px solid var(--gold);
  border-radius: 2px;
  padding: 15px 16px;
}

.page-about .about-partners strong {
  display: block;
  font-family: var(--serif);
  font-size: 16px;
  font-weight: 700;
  margin-bottom: 6px;
}

.page-about .about-partners p {
  margin: 0;
  font-size: 14px;
  line-height: 1.75;
}

/* ---------- 企业服务（深色章节） ---------- */
.page-about .about-part--ink {
  background: var(--indigo);
  color: var(--paper);
  border-top-color: rgba(244, 241, 234, .18);
  border-bottom: none;
}

.page-about .about-part--ink .about-part__side {
  border-bottom-color: rgba(244, 241, 234, .22);
}

.page-about .about-part--ink .about-part__num {
  color: var(--gold);
}

.page-about .about-part--ink .about-part__year {
  color: var(--gold);
}

.page-about .about-part--ink .about-part__tag {
  color: rgba(244, 241, 234, .66);
}

.page-about .about-part--ink .about-part__title {
  color: var(--paper);
}

.page-about .about-part--ink .about-part__body > p {
  color: rgba(244, 241, 234, .9);
}

.page-about .about-enterprise__stats {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 12px;
  margin: 24px 0 22px;
  padding: 0;
}

.page-about .about-enterprise__stats > div {
  border: 1px solid rgba(244, 241, 234, .24);
  border-radius: 3px;
  padding: 14px 16px;
  background: rgba(244, 241, 234, .04);
}

.page-about .about-enterprise__stats dt {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: .16em;
  color: var(--gold);
  margin-bottom: 6px;
}

.page-about .about-enterprise__stats dd {
  margin: 0;
  font-family: var(--serif);
  font-size: 22px;
  font-weight: 700;
  color: var(--paper);
}

.page-about .about-cta {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin: 24px 0 14px;
}

.page-about .about-cta .btn {
  text-decoration: none;
}

.page-about .about-cta__ghost {
  color: var(--paper);
  border-color: rgba(244, 241, 234, .55);
}

.page-about .about-cta__ghost:hover {
  border-color: var(--gold);
  color: var(--gold);
}

.page-about .about-enterprise__foot {
  margin: 0;
  font-size: 14px;
  line-height: 1.8;
  color: rgba(244, 241, 234, .78);
  max-width: 62ch;
}

/* ---------- 焦点可见 ---------- */
.page-about a:focus-visible,
.page-about summary:focus-visible {
  outline: 2px solid var(--indigo);
  outline-offset: 3px;
  border-radius: 2px;
}

.page-about .about-part--ink a:focus-visible {
  outline-color: var(--gold);
}

/* ---------- 媒体查询 ---------- */
@media (min-width: 560px) {
  .page-about .about-hero__stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .about-columns {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

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

@media (min-width: 700px) {
  .page-about .about-team__row {
    grid-template-columns: 78px 150px minmax(0, 1fr);
    align-items: baseline;
  }

  .page-about .about-team__num {
    grid-row: auto;
  }

  .page-about .about-team__text {
    grid-column: 3;
  }

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

@media (min-width: 900px) {
  .page-about .about-part__grid {
    grid-template-columns: 176px minmax(0, 1fr);
    gap: clamp(30px, 4.5vw, 64px);
    align-items: start;
  }

  .page-about .about-part__side {
    position: sticky;
    top: 92px;
    flex-direction: column;
    align-items: flex-start;
    gap: 8px;
    padding: 2px 0 2px 14px;
    border-bottom: none;
    border-left: 2px solid var(--cinnabar);
  }

  .page-about .about-part--ink .about-part__side {
    border-left-color: var(--gold);
    border-bottom: none;
  }

  .page-about .about-part--alt .about-part__side {
    border-left-color: var(--cinnabar);
  }

  .page-about .about-part__body > p,
  .page-about .about-note {
    max-width: 68ch;
  }
}

@media (min-width: 1100px) {
  .page-about .about-hero__title {
    max-width: 17ch;
  }

  .page-about .about-part {
    padding: clamp(64px, 7vw, 104px) 0;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-column,
  .page-about .about-years__item,
  .page-about .about-toc__link,
  .page-about .about-timeline__year {
    transition: none;
  }

  .page-about .about-column:hover {
    transform: none;
  }
}