.page-about {
  --about-line: rgba(166, 124, 46, .28);
  --about-line-soft: rgba(166, 124, 46, .14);
  --about-paper-line: rgba(46, 44, 39, .16);
  background-color: var(--ink);
  color: var(--paper);
  font-family: var(--font-sans);
  overflow-x: hidden;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  padding: 1.5rem 0 2.75rem;
  background:
    radial-gradient(115% 75% at 10% -15%, rgba(166, 124, 46, .22), transparent 62%),
    linear-gradient(180deg, var(--ink-2), var(--ink) 72%);
}

.page-about .about-hero__grid {
  display: grid;
  gap: 1.25rem;
  margin-top: 1.5rem;
}

.page-about .about-hero__no {
  font-family: var(--font-mono);
  font-size: clamp(4.5rem, 23vw, 8.5rem);
  font-weight: 500;
  line-height: .76;
  letter-spacing: -.05em;
  color: rgba(166, 124, 46, .32);
  border-left: 3px solid var(--gold);
  padding-left: .7rem;
  user-select: none;
}

.page-about .about-hero__title {
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(1.85rem, 6.8vw, 3.4rem);
  line-height: 1.18;
  letter-spacing: -.01em;
  margin: .55rem 0 1rem;
  color: var(--paper);
}

.page-about .about-hero .lead {
  color: var(--paper-2);
  max-width: 60ch;
}

.page-about .about-toc {
  display: flex;
  flex-wrap: wrap;
  gap: .5rem .55rem;
  margin-top: 2rem;
  padding-top: 1.25rem;
  border-top: 1px solid var(--about-line-soft);
}

.page-about .about-toc a {
  font-family: var(--font-mono);
  font-size: .76rem;
  letter-spacing: .04em;
  color: var(--paper-2);
  text-decoration: none;
  padding: .42rem .7rem;
  border: 1px solid var(--about-line-soft);
  border-radius: 2px;
  transition: border-color .18s ease, color .18s ease;
}

.page-about .about-toc a:hover,
.page-about .about-toc a:focus-visible {
  border-color: var(--gold);
  color: var(--gold-bright);
}

/* ---------- 通用章节 ---------- */
.page-about .about-sec {
  padding: 3rem 0;
  border-top: 1px solid var(--about-line-soft);
  scroll-margin-top: 84px;
}

.page-about .about-sec > .wrap > .eyebrow {
  color: var(--gold-bright);
}

.page-about .about-sec .section-title {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(1.5rem, 4.8vw, 2.4rem);
  line-height: 1.26;
  letter-spacing: -.005em;
  margin: .4rem 0 1rem;
  color: var(--paper);
}

.page-about .about-sec .lead {
  color: var(--paper-2);
  max-width: 64ch;
}

.page-about .about-sec--paper {
  background-color: var(--paper);
  color: var(--ink-2);
  border-top-color: var(--about-paper-line);
}

.page-about .about-sec--paper .section-title {
  color: var(--ink);
}

.page-about .about-sec--paper > .wrap > .eyebrow {
  color: var(--gold-deep);
}

.page-about .about-sec--paper .lead {
  color: var(--rock);
}

/* ---------- 两栏对照 ---------- */
.page-about .about-split {
  display: grid;
  gap: 1.5rem;
  margin-top: 1.25rem;
}

.page-about .about-split__main p {
  margin: 0 0 1.05rem;
  font-size: .96rem;
  line-height: 1.9;
  color: var(--paper-2);
}

.page-about .about-sec--paper .about-split__main p {
  color: var(--rock);
}

.page-about .about-split__side .note {
  border-left: 2px solid var(--gold);
  padding: .15rem 0 .15rem 1rem;
}

.page-about .about-split__side .note p {
  margin: 0;
  font-size: .88rem;
  line-height: 1.85;
  color: var(--warm);
}

.page-about .about-sec--paper .about-split__side .note p {
  color: var(--rock);
}

.page-about .about-split__side .note a {
  color: var(--gold-bright);
  text-decoration: underline;
  text-underline-offset: 3px;
}

.page-about .about-sec--paper .about-split__side .note a {
  color: var(--gold-deep);
}

/* ---------- 图片框 ---------- */
.page-about .about-media {
  margin: 1.5rem 0 1.75rem;
  padding: .5rem;
  background-color: var(--ink-2);
  border: 1px solid var(--about-line);
}

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

.page-about .about-media .media-caption {
  padding: .6rem .25rem .25rem;
  font-size: .78rem;
  line-height: 1.7;
  color: var(--warm);
}

.page-about .about-sec--paper .about-media {
  background-color: var(--paper-2);
  border-color: var(--about-paper-line);
}

.page-about .about-sec--paper .about-media .media-caption {
  color: var(--rock);
}

.page-about .about-media--narrow {
  max-width: 680px;
}

/* ---------- 归档卡片 ---------- */
.page-about .archive-grid {
  display: grid;
  gap: 1rem;
  margin: 1.75rem 0 1.5rem;
}

.page-about .archive-card {
  position: relative;
  background-color: var(--ink-2);
  border: 1px solid var(--about-line-soft);
  border-left: 2px solid var(--gold);
  padding: 1.15rem 1.1rem 1.25rem;
  transition: background-color .2s ease, border-color .2s ease;
}

.page-about .archive-card:hover {
  background-color: var(--rock);
  border-color: var(--gold);
}

.page-about .archive-card .archive-card__no {
  font-family: var(--font-mono);
  font-size: 1.35rem;
  line-height: 1;
  color: rgba(166, 124, 46, .58);
  margin: 0;
  transition: color .2s ease;
}

.page-about .archive-card:hover .archive-card__no,
.page-about .archive-card:focus-within .archive-card__no {
  color: var(--gold-bright);
}

.page-about .archive-card .archive-card__date {
  font-family: var(--font-mono);
  font-size: .72rem;
  letter-spacing: .04em;
  color: var(--warm);
  margin: .4rem 0 .8rem;
}

.page-about .archive-card h3 {
  font-size: 1rem;
  font-weight: 600;
  line-height: 1.45;
  color: var(--paper);
  margin: 0;
}

.page-about .archive-card ul {
  list-style: none;
  margin: .85rem 0 0;
  padding: 0;
}

.page-about .archive-card li {
  font-size: .86rem;
  line-height: 1.7;
  color: var(--paper-2);
  padding: .38rem 0;
  border-top: 1px dashed var(--about-line-soft);
}

/* ---------- 版本时间轴 ---------- */
.page-about .about-split--timeline {
  align-items: start;
}

.page-about .tl {
  list-style: none;
  position: relative;
  margin: 1.75rem 0 0;
  padding: 0 0 0 2.5rem;
}

.page-about .tl::before {
  content: "";
  position: absolute;
  left: .25rem;
  top: .55rem;
  bottom: .55rem;
  width: 2px;
  background: linear-gradient(180deg, var(--gold) 0%, rgba(166, 124, 46, .12) 100%);
}

.page-about .tl__node {
  position: relative;
  padding-bottom: 1.4rem;
}

.page-about .tl__node::before {
  content: "";
  position: absolute;
  left: -2.5rem;
  top: .55rem;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background-color: var(--gold);
  box-shadow: 0 0 0 4px var(--ink);
}

.page-about .tl__detail summary {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: .5rem;
  cursor: pointer;
  list-style: none;
  padding: .3rem 0;
}

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

.page-about .tl__detail summary::after {
  content: "+";
  font-family: var(--font-mono);
  font-size: 1rem;
  color: var(--gold);
  margin-left: auto;
}

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

.page-about .tl__chip {
  font-family: var(--font-mono);
  font-size: .88rem;
  letter-spacing: .08em;
  color: var(--gold-bright);
  border: 1px solid var(--about-line);
  padding: .08rem .45rem;
}

.page-about .tl__title {
  font-weight: 600;
  font-size: 1rem;
  line-height: 1.5;
  color: var(--paper);
}

.page-about .tl__detail p {
  margin: .6rem 0 0;
  font-size: .92rem;
  line-height: 1.85;
  color: var(--paper-2);
}

.page-about .about-split--timeline .about-media--square {
  margin-top: 1.75rem;
}

/* ---------- 维护与协作 ---------- */
.page-about .stat-row {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1.15rem;
  margin: 1.9rem 0 0;
}

.page-about .stat {
  border-top: 2px solid var(--gold-deep);
  padding-top: .6rem;
}

.page-about .stat__num {
  font-family: var(--font-mono);
  font-weight: 500;
  font-size: clamp(1.6rem, 5.5vw, 2.3rem);
  line-height: 1;
  color: var(--gold-deep);
  margin: 0;
}

.page-about .stat__label {
  margin: .45rem 0 0;
  font-size: .82rem;
  line-height: 1.6;
  color: var(--rock);
}

.page-about .team-list {
  list-style: none;
  display: grid;
  gap: 1px;
  margin: 2.25rem 0 0;
  padding: 0;
  background-color: var(--about-paper-line);
  border: 1px solid var(--about-paper-line);
}

.page-about .team-item {
  background-color: var(--paper);
  padding: 1.1rem 1.05rem 1.25rem;
}

.page-about .team-item .team-item__no {
  font-family: var(--font-mono);
  font-size: .78rem;
  letter-spacing: .1em;
  color: var(--gold-deep);
  margin: 0 0 .5rem;
}

.page-about .team-item h3 {
  font-size: .98rem;
  font-weight: 600;
  color: var(--ink);
  margin: 0 0 .45rem;
}

.page-about .team-item p {
  margin: 0;
  font-size: .87rem;
  line-height: 1.8;
  color: var(--rock);
}

/* ---------- 回访路径 ---------- */
.page-about .steps {
  list-style: none;
  display: grid;
  gap: 1rem;
  margin: 1.75rem 0 2rem;
  padding: 0;
}

.page-about .step {
  background-color: var(--ink-2);
  border: 1px solid var(--about-line-soft);
  padding: 1.15rem 1.1rem 1.3rem;
  transition: border-color .2s ease;
}

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

.page-about .step .step__no {
  font-family: var(--font-mono);
  font-size: .76rem;
  letter-spacing: .12em;
  color: var(--gold-bright);
  margin: 0;
}

.page-about .step h3 {
  font-size: 1rem;
  font-weight: 600;
  color: var(--paper);
  margin: .5rem 0 .45rem;
}

.page-about .step p {
  margin: 0;
  font-size: .89rem;
  line-height: 1.85;
  color: var(--paper-2);
}

.page-about .entry-list {
  list-style: none;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 0 1.25rem;
  margin: 0 0 2rem;
  padding: 0;
}

.page-about .entry-item {
  display: flex;
  align-items: baseline;
  gap: .55rem;
  border-top: 1px solid var(--about-line);
  padding: .75rem 0;
}

.page-about .entry-item .entry-item__no {
  font-family: var(--font-mono);
  font-size: .72rem;
  color: var(--gold);
}

.page-about .entry-item .entry-item__name {
  font-size: .92rem;
  font-weight: 500;
  color: var(--paper);
}

/* ---------- 桌面增强 ---------- */
@media (min-width: 720px) {
  .page-about .archive-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .page-about .stat-row {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

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

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

@media (min-width: 900px) {
  .page-about .about-hero {
    padding: 2.5rem 0 4rem;
  }

  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 230px) minmax(0, 1fr);
    gap: 3.5rem;
    align-items: start;
    margin-top: 2.5rem;
  }

  .page-about .about-hero__no {
    font-size: clamp(7rem, 11vw, 10.5rem);
  }

  .page-about .about-sec {
    padding: 5rem 0;
  }

  .page-about .about-split {
    grid-template-columns: minmax(0, 7fr) minmax(0, 4fr);
    gap: 3rem;
    align-items: start;
  }

  .page-about .about-split--timeline {
    grid-template-columns: minmax(0, 6fr) minmax(0, 5fr);
    gap: 3.5rem;
  }

  .page-about .about-split--timeline .about-media--square {
    margin-top: 1.75rem;
  }

  .page-about .entry-list {
    grid-template-columns: repeat(5, minmax(0, 1fr));
  }
}

@media (min-width: 1100px) {
  .page-about .about-split__main p {
    font-size: 1rem;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .archive-card,
  .page-about .step,
  .page-about .about-toc a {
    transition: none;
  }
}