.page-about {
  --about-ink-soft: rgba(27, 42, 54, 0.72);
  --about-ink-faint: rgba(27, 42, 54, 0.52);
  --about-tint: rgba(20, 64, 95, 0.05);
  background: var(--paper);
  color: var(--graphite);
  font-family: var(--sans);
}

.page-about .mono {
  font-family: var(--mono);
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  padding: clamp(48px, 8vw, 88px) 0 clamp(56px, 9vw, 104px);
  background:
    radial-gradient(115% 85% at 10% 0%, rgba(47, 227, 210, 0.16), transparent 62%),
    linear-gradient(180deg, var(--abyss) 0%, var(--deep) 100%);
  color: var(--paper);
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image: linear-gradient(to right, rgba(199, 211, 220, 0.07) 1px, transparent 1px);
  background-size: 88px 100%;
}

.page-about .about-hero__inner {
  position: relative;
  z-index: 1;
}

.page-about .about-crumbs {
  margin-bottom: 28px;
  font-size: 13px;
  color: var(--mist-70);
}

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

.page-about .about-crumbs a:hover,
.page-about .about-crumbs a:focus-visible {
  border-bottom-color: var(--cyan);
}

.page-about .about-crumbs .crumbs__sep {
  margin: 0 8px;
  color: rgba(199, 211, 220, 0.42);
}

.page-about .about-kicker {
  margin: 0 0 18px;
  font-size: 12px;
  color: var(--cyan);
}

.page-about .about-hero__title {
  margin: 0;
  font-family: var(--display);
  font-weight: 800;
  font-size: clamp(40px, 9vw, 96px);
  line-height: 1.02;
  letter-spacing: -0.02em;
  color: var(--paper);
}

.page-about .about-hero__lead {
  margin: 26px 0 0;
  max-width: 46ch;
  font-size: 16px;
  line-height: 1.9;
  color: var(--mist);
}

.page-about .about-hero__facts {
  list-style: none;
  margin: 44px 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  border-top: 1px solid var(--rule-dark);
}

.page-about .about-fact {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 18px 14px 0 0;
  border-left: 1px solid var(--rule-dark);
  padding-left: 16px;
}

.page-about .about-fact:nth-child(odd) {
  border-left: 0;
  padding-left: 0;
}

.page-about .about-fact__num {
  font-family: var(--display);
  font-weight: 800;
  font-size: clamp(24px, 4vw, 34px);
  letter-spacing: -0.02em;
  color: var(--paper);
}

.page-about .about-fact__label {
  font-size: 11px;
  color: var(--mist-70);
}

.page-about .about-hero__rot {
  display: none;
  writing-mode: vertical-rl;
  font-size: 11px;
  color: var(--mist-70);
  margin: 0;
}

/* ---------- 通用章节 ---------- */
.page-about .about-section {
  padding: clamp(52px, 8vw, 96px) 0;
  border-top: 1px solid var(--line);
}

.page-about .about-section--dark {
  border-top: 0;
  background: linear-gradient(180deg, var(--deep) 0%, var(--abyss) 100%);
  color: var(--paper);
}

.page-about .about-head {
  display: grid;
  gap: 14px;
  margin-bottom: clamp(32px, 5vw, 48px);
}

.page-about .about-sec-num {
  font-family: var(--display);
  font-weight: 800;
  font-size: clamp(40px, 8vw, 84px);
  line-height: 0.9;
  letter-spacing: -0.03em;
  color: var(--hull);
}

@supports (-webkit-text-stroke: 1px #000) {
  .page-about .about-sec-num {
    color: transparent;
    -webkit-text-stroke: 1.5px var(--hull);
  }
}

.page-about .about-head h2 {
  margin: 0;
  font-size: clamp(24px, 4.2vw, 36px);
  line-height: 1.28;
  letter-spacing: -0.01em;
  font-weight: 700;
}

.page-about .about-head p {
  margin: 0;
  max-width: 62ch;
  font-size: 16px;
  line-height: 1.85;
  color: var(--about-ink-soft);
}

.page-about .about-section--dark .about-head p {
  color: var(--mist-70);
}

@supports (-webkit-text-stroke: 1px #000) {
  .page-about .about-section--dark .about-sec-num {
    -webkit-text-stroke-color: var(--cyan);
  }
}

/* ---------- 01 起点 ---------- */
.page-about .about-origin {
  display: grid;
  gap: 28px;
}

.page-about .about-origin__text p {
  margin: 0 0 18px;
  font-size: 16px;
  line-height: 1.9;
  color: var(--about-ink-soft);
}

.page-about .about-origin__text p:last-child {
  margin-bottom: 0;
}

.page-about .about-quote {
  margin: 0;
  padding: 24px 0 0 22px;
  border-left: 3px solid var(--cyan);
  border-top: 1px solid var(--line);
}

.page-about .about-quote blockquote {
  margin: 0;
  font-size: 24px;
  line-height: 1.7;
  letter-spacing: -0.01em;
  color: var(--graphite);
}

.page-about .about-quote figcaption {
  margin-top: 18px;
  font-size: 11px;
  color: var(--about-ink-faint);
}

/* ---------- 02 时间轴 ---------- */
.page-about .timeline {
  position: relative;
  list-style: none;
  margin: 0;
  padding: 0 0 0 26px;
}

.page-about .timeline::before {
  content: "";
  position: absolute;
  left: 5px;
  top: 8px;
  bottom: 8px;
  width: 1px;
  background: var(--line);
}

.page-about .tl-item {
  position: relative;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 10px;
  padding-bottom: 40px;
}

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

.page-about .tl-item::before {
  content: "";
  position: absolute;
  left: -26px;
  top: 7px;
  width: 11px;
  height: 11px;
  border-radius: 50%;
  background: var(--amber);
  box-shadow: 0 0 0 3px var(--paper);
  transition: transform 220ms ease, box-shadow 220ms ease;
}

.page-about .tl-item:hover::before,
.page-about .tl-item:focus-within::before {
  transform: scale(1.25);
  box-shadow: 0 0 0 3px var(--paper), 0 0 0 7px rgba(255, 194, 75, 0.24);
}

.page-about .tl-year {
  font-size: 13px;
  color: var(--hull);
  padding-top: 2px;
}

.page-about .tl-body {
  position: relative;
}

.page-about .tl-title {
  margin: 0 0 8px;
  font-size: 20px;
  line-height: 1.4;
  font-weight: 700;
  color: var(--graphite);
}

.page-about .tl-text {
  margin: 0;
  font-size: 15px;
  line-height: 1.85;
  color: var(--about-ink-soft);
}

.page-about .tl-note {
  margin: 12px 0 0;
  padding-left: 14px;
  border-left: 1px solid var(--line);
  font-size: 13px;
  line-height: 1.8;
  color: var(--about-ink-faint);
  overflow: hidden;
  transition: max-height 240ms ease, opacity 240ms ease;
}

@media (hover: hover) and (prefers-reduced-motion: no-preference) {
  .page-about .tl-note {
    max-height: 0;
    opacity: 0;
  }

  .page-about .tl-item:hover .tl-note,
  .page-about .tl-item:focus-within .tl-note {
    max-height: 6em;
    opacity: 1;
  }
}

/* ---------- 图片 ---------- */
.page-about .about-figure {
  margin: 0;
}

.page-about .about-figure img {
  display: block;
  width: 100%;
  height: auto;
  max-width: 100%;
  border: 1px solid var(--line);
  object-fit: cover;
  background: var(--hull);
}

.page-about .about-figure figcaption {
  margin-top: 12px;
  font-size: 11px;
  color: var(--about-ink-faint);
}

.page-about .about-figure--bleed {
  margin-top: clamp(36px, 6vw, 64px);
}

.page-about .about-figure--bleed img {
  aspect-ratio: 14 / 9;
}

.page-about .about-figure--square img {
  aspect-ratio: 1 / 1;
}

.page-about .about-section--dark .about-figure img {
  border-color: var(--rule-dark);
}

.page-about .about-section--dark .about-figure figcaption {
  color: var(--mist-70);
}

/* ---------- 03 校验 ---------- */
.page-about .about-check {
  display: grid;
  gap: 32px;
}

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

.page-about .check-item {
  padding: 20px 0;
  border-bottom: 1px solid var(--line);
}

.page-about .check-item dt {
  font-size: 12px;
  color: var(--coral);
  margin-bottom: 8px;
}

.page-about .check-item dd {
  margin: 0;
  font-size: 15px;
  line-height: 1.85;
  color: var(--about-ink-soft);
}

.page-about .about-check__note {
  margin: 24px 0 0;
  font-size: 14px;
  line-height: 1.85;
  color: var(--hull);
  padding: 16px 0 0 16px;
  border-left: 3px solid var(--coral);
}

/* ---------- 04 分工折叠 ---------- */
.page-about .crew {
  display: grid;
  gap: 14px;
}

.page-about .crew-item {
  border: 1px solid var(--line);
  background: #fff;
}

.page-about .crew-item summary {
  display: grid;
  grid-template-columns: 34px minmax(0, 1fr);
  gap: 4px 10px;
  align-items: center;
  padding: 18px 18px;
  cursor: pointer;
  list-style: none;
}

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

.page-about .crew-item summary::after {
  content: "+";
  grid-column: 2;
  grid-row: 2;
  justify-self: start;
  font-family: var(--mono);
  font-size: 13px;
  color: var(--hull);
}

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

.page-about .crew-item[open] summary {
  background: var(--about-tint);
  border-bottom: 1px solid var(--line);
}

.page-about .crew-num {
  grid-row: 1 / span 2;
  font-size: 22px;
  color: var(--cyan);
  font-weight: 700;
  text-shadow: 0 0 0 var(--cyan);
  -webkit-text-stroke: 0.5px var(--hull);
}

.page-about .crew-name {
  font-size: 18px;
  font-weight: 700;
  letter-spacing: -0.01em;
}

.page-about .crew-meta {
  font-size: 11px;
  color: var(--about-ink-faint);
}

.page-about .crew-body {
  padding: 18px;
}

.page-about .crew-body p {
  margin: 0 0 14px;
  font-size: 15px;
  line-height: 1.85;
  color: var(--about-ink-soft);
}

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

.page-about .crew-list li {
  position: relative;
  padding-left: 20px;
  font-size: 14px;
  line-height: 1.75;
  color: var(--graphite);
}

.page-about .crew-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 9px;
  width: 8px;
  height: 1px;
  background: var(--cyan);
}

/* ---------- 05 对照表 ---------- */
.page-about .diff-wrap {
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  border-top: 1px solid var(--line);
}

.page-about .diff-table {
  width: 100%;
  min-width: 640px;
  border-collapse: collapse;
  font-size: 15px;
}

.page-about .diff-table caption {
  text-align: left;
  padding: 0 0 14px;
  font-size: 11px;
  color: var(--about-ink-faint);
}

.page-about .diff-table th,
.page-about .diff-table td {
  text-align: left;
  vertical-align: top;
  padding: 16px 18px;
  border-bottom: 1px solid var(--line);
  line-height: 1.75;
}

.page-about .diff-table thead th {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  color: var(--hull);
  background: var(--about-tint);
  font-weight: 500;
}

.page-about .diff-table tbody th {
  width: 20%;
  font-weight: 700;
  color: var(--graphite);
  font-size: 14px;
}

.page-about .diff-table td {
  color: var(--about-ink-soft);
  width: 40%;
}

.page-about .diff-table td:last-child {
  color: var(--graphite);
  border-left: 1px solid var(--line);
}

.page-about .diff-table tbody tr:nth-child(even) th,
.page-about .diff-table tbody tr:nth-child(even) td {
  background: rgba(20, 64, 95, 0.03);
}

.page-about .diff-foot {
  margin: 24px 0 0;
  max-width: 60ch;
  font-size: 14px;
  line-height: 1.85;
  color: var(--about-ink-faint);
}

/* ---------- 06 读者 ---------- */
.page-about .reader-grid {
  display: grid;
  gap: 32px;
}

.page-about .reader-stats {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--rule-dark);
  border-top: 1px solid var(--rule-dark);
}

.page-about .reader-stat {
  background: var(--deep);
  padding: 20px 18px;
  display: grid;
  gap: 6px;
}

.page-about .reader-stat__num {
  font-family: var(--display);
  font-weight: 800;
  font-size: clamp(28px, 5.4vw, 44px);
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--cyan);
}

.page-about .reader-stat__label {
  font-size: 11px;
  color: var(--amber);
}

.page-about .reader-stat__text {
  font-size: 14px;
  line-height: 1.8;
  color: var(--mist-70);
}

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

.page-about .about-figure--city img {
  aspect-ratio: 3 / 2;
  border-color: var(--rule-dark);
}

/* ---------- 下一步 ---------- */
.page-about .about-next {
  margin-top: clamp(40px, 6vw, 64px);
  padding-top: 28px;
  border-top: 1px solid var(--rule-dark);
}

.page-about .about-next__lead {
  margin: 0 0 8px;
  font-size: 13px;
  color: var(--mist-70);
}

.page-about .about-next__list {
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .about-next__item + .about-next__item {
  border-top: 1px solid var(--rule-dark);
}

.page-about .about-next__item a {
  display: grid;
  grid-template-columns: 36px minmax(0, 1fr) 24px;
  gap: 12px;
  align-items: center;
  padding: 18px 0;
  text-decoration: none;
  color: var(--paper);
  transition: color 180ms ease, padding-left 180ms ease;
}

.page-about .about-next__item a:hover,
.page-about .about-next__item a:focus-visible {
  color: var(--cyan);
  padding-left: 8px;
}

.page-about .about-next__num {
  font-size: 12px;
  color: var(--coral);
}

.page-about .about-next__title {
  font-size: 16px;
  line-height: 1.5;
}

.page-about .about-next__arrow {
  justify-self: end;
  font-size: 18px;
  color: var(--cyan);
}

/* ---------- 断点 ---------- */
@media (min-width: 700px) {
  .page-about .about-hero__facts {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .about-fact:nth-child(odd) {
    border-left: 1px solid var(--rule-dark);
    padding-left: 18px;
  }

  .page-about .about-fact:first-child {
    border-left: 0;
    padding-left: 0;
  }

  .page-about .about-origin {
    grid-template-columns: 7fr 5fr;
    gap: 40px;
    align-items: start;
  }

  .page-about .about-check {
    grid-template-columns: 7fr 5fr;
    gap: 44px;
    align-items: start;
  }

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

@media (min-width: 900px) {
  .page-about .tl-item {
    grid-template-columns: 150px minmax(0, 1fr);
    column-gap: 36px;
    padding-bottom: 48px;
  }

  .page-about .tl-year {
    text-align: right;
    font-size: 14px;
    padding-top: 3px;
    color: var(--hull);
  }

  .page-about .tl-item::before {
    left: -26px;
    top: 9px;
  }

  .page-about .timeline {
    padding-left: 30px;
  }

  .page-about .timeline::before {
    left: 6px;
  }

  .page-about .about-hero__inner {
    padding-right: 70px;
  }

  .page-about .about-hero__rot {
    display: block;
    position: absolute;
    right: 0;
    top: 96px;
  }
}

@media (min-width: 1024px) {
  .page-about .about-figure--bleed {
    margin-left: calc(var(--gutter) * -1);
    margin-right: calc(var(--gutter) * -1);
  }

  .page-about .reader-grid {
    grid-template-columns: 5fr 7fr;
    gap: 48px;
    align-items: stretch;
  }

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

  .page-about .about-next__item a {
    grid-template-columns: 48px minmax(0, 1fr) 32px;
    padding: 22px 0;
  }

  .page-about .about-next__title {
    font-size: 18px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .tl-item::before,
  .page-about .tl-note,
  .page-about .about-next__item a {
    transition: none;
  }
}