.page-about {
  --about-index-w: 168px;
  --about-gap: clamp(20px, 3vw, 44px);
  --about-paper-line: rgba(42, 26, 18, 0.18);
  --about-paper-soft: rgba(42, 26, 18, 0.62);
  color: var(--white);
  overflow-x: clip;
}

.page-about a:focus-visible,
.page-about summary:focus-visible,
.page-about .about-tl-item:focus-visible {
  outline: 2px solid var(--orange);
  outline-offset: 3px;
  box-shadow: 0 0 0 4px rgba(47, 243, 220, 0.32);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  padding-block: clamp(24px, 3.4vw, 48px) clamp(26px, 3.6vw, 52px);
  border-bottom: 1px solid var(--line);
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image:
    linear-gradient(var(--line-soft) 1px, transparent 1px),
    linear-gradient(90deg, var(--line-soft) 1px, transparent 1px);
  background-size: 48px 48px;
  -webkit-mask-image: linear-gradient(180deg, rgba(0, 0, 0, 0.55), transparent 72%);
  mask-image: linear-gradient(180deg, rgba(0, 0, 0, 0.55), transparent 72%);
}

.page-about .about-hero > * {
  position: relative;
  z-index: 1;
}

.page-about .about-hero .breadcrumbs {
  margin: 0 0 20px;
  font-size: 0.75rem;
}

.page-about .about-hero-grid {
  display: grid;
  gap: clamp(22px, 3vw, 40px);
}

.page-about .eyebrow {
  margin: 0 0 14px;
}

.page-about h1 {
  margin: 0;
  font-family: var(--font-display);
  font-size: clamp(1.95rem, 5vw, 3.35rem);
  line-height: 1.06;
  letter-spacing: -0.01em;
  font-weight: 700;
  color: var(--white);
}

.page-about .about-lede {
  margin: 18px 0 0;
  max-width: 34em;
  font-size: 0.96rem;
  line-height: 1.85;
  color: var(--steel);
}

.page-about .about-stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: 0;
  background: var(--line-soft);
  border: 1px solid var(--line);
  border-left: 3px solid var(--orange);
}

.page-about .about-stats > div {
  background: var(--ink);
  padding: 14px 16px;
}

.page-about .about-stats dt {
  font-family: var(--font-mono);
  font-size: 0.66rem;
  letter-spacing: 0.14em;
  color: var(--steel);
}

.page-about .about-stats dd {
  display: flex;
  align-items: baseline;
  gap: 4px;
  margin: 6px 0 0;
}

.page-about .about-stats .score {
  font-family: var(--font-display);
  font-size: clamp(1.7rem, 3.4vw, 2.4rem);
  line-height: 1;
  color: var(--orange);
}

.page-about .about-unit {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  color: var(--steel);
}

/* ---------- 主体两栏 ---------- */
.page-about .about-body {
  display: grid;
  gap: var(--about-gap);
  padding-block: clamp(26px, 4vw, 52px) clamp(44px, 6vw, 88px);
}

.page-about .about-index {
  border-top: 1px solid var(--line-strong);
  padding-top: 10px;
}

.page-about .about-index-kicker {
  margin: 0 0 10px;
  font-size: 0.62rem;
  letter-spacing: 0.22em;
  color: var(--steel);
}

.page-about .about-index-list {
  display: flex;
  gap: 4px;
  margin: 0;
  padding: 0 0 4px;
  list-style: none;
  overflow-x: auto;
  scrollbar-width: thin;
}

.page-about .about-index-list a {
  display: flex;
  align-items: baseline;
  gap: 7px;
  padding: 8px 10px;
  font-size: 0.78rem;
  line-height: 1.3;
  color: var(--steel);
  text-decoration: none;
  white-space: nowrap;
  border-bottom: 2px solid transparent;
  transition: color 0.2s var(--ease), border-color 0.2s var(--ease), background 0.2s var(--ease);
}

.page-about .about-index-list a .mono {
  color: var(--amber);
  font-size: 0.66rem;
}

.page-about .about-index-list a:hover,
.page-about .about-index-list a:focus-visible {
  color: var(--white);
  border-bottom-color: var(--orange);
  background: rgba(47, 243, 220, 0.07);
}

/* ---------- 章节 ---------- */
.page-about .about-chapter {
  scroll-margin-top: 96px;
}

.page-about .about-chapter + .about-chapter {
  margin-top: clamp(38px, 5vw, 68px);
}

.page-about .about-chapter-head {
  display: flex;
  align-items: baseline;
  gap: 12px;
  padding-bottom: 10px;
  margin-bottom: clamp(16px, 2.4vw, 26px);
  border-bottom: 1px solid var(--line-strong);
}

.page-about .about-chapter-num {
  margin: 0;
  font-size: 0.76rem;
  letter-spacing: 0.18em;
  color: var(--orange);
}

.page-about .about-chapter-head h2 {
  margin: 0;
  font-family: var(--font-display);
  font-size: clamp(1.32rem, 2.6vw, 2rem);
  line-height: 1.18;
  letter-spacing: -0.005em;
  color: var(--white);
}

/* ---------- 奶油纸面块 ---------- */
.page-about .about-paper {
  padding: clamp(18px, 2.8vw, 34px);
  background: var(--paper);
  color: var(--brown);
  border-left: 3px solid var(--amber);
}

.page-about .about-paper p {
  margin: 0 0 1em;
  font-size: 0.94rem;
  line-height: 1.85;
}

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

.page-about .about-split {
  display: grid;
  gap: clamp(18px, 2.6vw, 30px);
}

.page-about .about-copy p {
  max-width: 36em;
}

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

.page-about .about-figure .media {
  border: 1px solid var(--line-strong);
}

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

.page-about .about-figure--tall .media {
  aspect-ratio: 3 / 4;
}

.page-about .about-figure--wide .media {
  aspect-ratio: 16 / 9;
}

.page-about .about-figure figcaption {
  margin-top: 8px;
  font-size: 0.72rem;
  line-height: 1.6;
  color: var(--steel);
}

.page-about .about-paper figcaption {
  color: var(--about-paper-soft);
}

.page-about .about-wide-figure,
.page-about .about-duty-figure {
  margin-top: clamp(18px, 2.6vw, 30px);
}

/* ---------- 深色章节 ---------- */
.page-about .about-chapter--dark .about-lead-dark {
  margin: 0 0 clamp(20px, 3vw, 30px);
  max-width: 36em;
  font-size: 0.94rem;
  line-height: 1.85;
  color: var(--steel);
}

/* ---------- 时间线 ---------- */
.page-about .about-tl {
  position: relative;
  margin: 0;
  padding: 4px 0 0 24px;
  list-style: none;
}

.page-about .about-tl::before {
  content: "";
  position: absolute;
  left: 5px;
  top: 8px;
  bottom: 8px;
  width: 2px;
  background: linear-gradient(180deg, var(--orange), var(--cyan) 62%, rgba(201, 154, 69, 0.34));
}

.page-about .about-tl-item {
  position: relative;
  padding-bottom: clamp(22px, 3vw, 34px);
}

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

.page-about .about-tl-item::before {
  content: "";
  position: absolute;
  left: -24px;
  top: 7px;
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--ink);
  border: 2px solid var(--orange);
  box-shadow: 0 0 0 3px rgba(255, 91, 34, 0.15);
}

.page-about .about-tl-year {
  margin: 0 0 5px;
  font-size: 0.76rem;
  letter-spacing: 0.16em;
  color: var(--cyan);
}

.page-about .about-tl-body h3 {
  margin: 0 0 6px;
  font-size: 1.02rem;
  line-height: 1.4;
  color: var(--white);
}

.page-about .about-tl-body > p {
  margin: 0;
  max-width: 40em;
  font-size: 0.89rem;
  line-height: 1.8;
  color: var(--steel);
}

.page-about .about-tl-note {
  overflow: hidden;
  max-height: 0;
  margin-top: 0;
  padding-left: 10px;
  border-left: 2px solid var(--pink);
  opacity: 0;
  font-size: 0.84rem !important;
  color: rgba(247, 250, 255, 0.72) !important;
  transition: max-height 0.3s var(--ease), opacity 0.3s var(--ease), margin-top 0.3s var(--ease);
}

.page-about .about-tl-item:hover .about-tl-note,
.page-about .about-tl-item:focus-within .about-tl-note,
.page-about .about-tl-item:focus .about-tl-note {
  max-height: 9em;
  margin-top: 9px;
  opacity: 1;
}

/* ---------- 城市赛区 ---------- */
.page-about .about-cities {
  margin-top: clamp(18px, 2.6vw, 28px);
  border-top: 1px solid var(--line);
}

.page-about .about-cities-kicker {
  margin: 0;
  padding: 12px 0 6px;
  font-size: 0.64rem;
  letter-spacing: 0.2em;
  color: var(--amber);
}

.page-about .about-city-item {
  border-bottom: 1px solid var(--line);
}

.page-about .about-city-item summary {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 12px 2px;
  font-size: 0.92rem;
  color: var(--white);
  cursor: pointer;
  list-style: none;
}

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

.page-about .about-city-item summary::after {
  content: "+";
  font-family: var(--font-mono);
  font-size: 0.9rem;
  color: var(--orange);
  transition: transform 0.2s var(--ease);
}

.page-about .about-city-item[open] summary::after {
  content: "−";
  color: var(--cyan);
}

.page-about .about-city-item summary:hover {
  color: var(--cyan);
}

.page-about .about-city-body {
  margin: 0;
  padding: 0 0 14px 2px;
  max-width: 38em;
  font-size: 0.86rem;
  line-height: 1.8;
  color: var(--steel);
}

/* ---------- 协作卡 ---------- */
.page-about .about-partner {
  margin-top: clamp(18px, 2.6vw, 28px);
  padding: clamp(18px, 2.6vw, 28px);
  background: var(--ink-2);
  border: 1px solid var(--line);
  border-top: 3px solid var(--cyan);
}

.page-about .about-partner h3 {
  margin: 0 0 8px;
  font-size: 1.05rem;
  color: var(--white);
}

.page-about .about-partner p {
  margin: 0 0 18px;
  max-width: 34em;
  font-size: 0.89rem;
  line-height: 1.8;
  color: var(--steel);
}

/* ---------- 值班清单 ---------- */
.page-about .about-duty-list {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  margin: 0;
  padding: 1px;
  list-style: none;
  background: var(--line-soft);
  border: 1px solid var(--line);
}

.page-about .about-duty-list > li {
  padding: 16px 18px;
  background: var(--ink);
  border-left: 2px solid transparent;
  transition: border-color 0.2s var(--ease), background 0.2s var(--ease);
}

.page-about .about-duty-list > li:hover {
  background: var(--ink-2);
  border-left-color: var(--cyan);
}

.page-about .about-duty-num {
  margin: 0 0 6px;
  font-size: 0.72rem;
  letter-spacing: 0.1em;
  color: var(--orange);
}

.page-about .about-duty-list h3 {
  margin: 0 0 6px;
  font-size: 0.98rem;
  color: var(--white);
}

.page-about .about-duty-list p:last-child {
  margin: 0;
  font-size: 0.85rem;
  line-height: 1.75;
  color: var(--steel);
}

/* ---------- 视觉母题 ---------- */
.page-about .about-visual {
  display: grid;
  gap: clamp(18px, 2.6vw, 30px);
}

.page-about .about-copy--dark p {
  margin: 0 0 1em;
  max-width: 36em;
  font-size: 0.94rem;
  line-height: 1.85;
  color: var(--steel);
}

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

.page-about .about-city {
  display: block;
  width: 100%;
  height: auto;
  padding: 12px 0;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.page-about .about-city .city-mid {
  stroke: var(--cyan);
  stroke-width: 1;
  stroke-dasharray: 6 6;
  opacity: 0.85;
}

.page-about .about-city .city-circle {
  fill: none;
  stroke: var(--orange);
  stroke-width: 1.4;
}

.page-about .about-city .city-block {
  fill: none;
  stroke: var(--steel);
  stroke-width: 1;
  opacity: 0.55;
}

.page-about .about-city .city-ground {
  stroke: var(--amber);
  stroke-width: 1.2;
}

/* ---------- 下一步 ---------- */
.page-about .about-next {
  display: grid;
  gap: 1px;
  background: var(--line-soft);
  border: 1px solid var(--line);
}

.page-about .about-next-card {
  display: block;
  padding: clamp(16px, 2.4vw, 24px);
  background: var(--ink);
  color: var(--white);
  text-decoration: none;
  border-left: 2px solid transparent;
  transition: transform 0.2s var(--ease), border-color 0.2s var(--ease), background 0.2s var(--ease);
}

.page-about .about-next-card:hover,
.page-about .about-next-card:focus-visible {
  transform: translateY(-2px);
  border-left-color: var(--orange);
  background: var(--ink-2);
}

.page-about .about-next-num {
  margin: 0 0 8px;
  font-size: 0.66rem;
  letter-spacing: 0.2em;
  color: var(--amber);
}

.page-about .about-next-card h3 {
  margin: 0 0 8px;
  font-size: 1rem;
  color: var(--white);
}

.page-about .about-next-card p {
  margin: 0 0 14px;
  font-size: 0.85rem;
  line-height: 1.75;
  color: var(--steel);
}

.page-about .about-next-go {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.06em;
  color: var(--cyan);
  border-bottom: 1px solid rgba(47, 243, 220, 0.4);
}

/* ---------- 断点 ---------- */
@media (min-width: 700px) {
  .page-about .about-split {
    grid-template-columns: minmax(0, 1.35fr) minmax(0, 0.8fr);
    align-items: start;
  }

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

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

@media (min-width: 900px) {
  .page-about .about-hero-grid {
    grid-template-columns: minmax(0, 1.55fr) minmax(0, 1fr);
    align-items: end;
  }

  .page-about .about-body {
    grid-template-columns: var(--about-index-w) minmax(0, 1fr);
    align-items: start;
  }

  .page-about .about-index {
    position: sticky;
    top: 24px;
  }

  .page-about .about-index-list {
    flex-direction: column;
    gap: 0;
    overflow: visible;
    padding-bottom: 0;
  }

  .page-about .about-index-list a {
    border-bottom: 0;
    border-left: 2px solid transparent;
    padding: 9px 0 9px 12px;
    white-space: normal;
  }

  .page-about .about-index-list a:hover,
  .page-about .about-index-list a:focus-visible {
    border-left-color: var(--orange);
    border-bottom-color: transparent;
  }

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

@media (min-width: 1100px) {
  .page-about .about-duty-list {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

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

@media (hover: none) {
  .page-about .about-tl-note {
    max-height: none;
    margin-top: 9px;
    opacity: 1;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-tl-note,
  .page-about .about-next-card,
  .page-about .about-duty-list > li,
  .page-about .about-index-list a {
    transition: none;
  }

  .page-about .about-next-card:hover,
  .page-about .about-next-card:focus-visible {
    transform: none;
  }
}
<<<END>>>