.page-about {
  --about-rail-w: 212px;
  --about-line: 5px;
  --about-gutter: 26px;
  position: relative;
  padding-bottom: 88px;
}

/* ---------- 面包屑与首屏 ---------- */
.page-about .crumbs {
  margin: 26px 0 18px;
}
.page-about .about-head {
  position: relative;
  padding: 6px 0 40px;
  border-bottom: 1px solid var(--line);
  background: linear-gradient(104deg, transparent 54%, rgba(255, 179, 71, 0.07) 54.4%, transparent 79%);
}
.page-about .about-head::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: -1px;
  width: 132px;
  height: 2px;
  background: linear-gradient(90deg, var(--red), var(--amber));
}
.page-about .about-head__eyebrow {
  margin: 0 0 14px;
  font-size: 12px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--amber);
}
.page-about .page-head__title {
  margin: 0 0 18px;
  font-size: clamp(30px, 6.4vw, 54px);
  line-height: 1.18;
  font-weight: 800;
  letter-spacing: 0.02em;
  color: var(--white);
  max-width: 22em;
}
.page-about .page-head__lede {
  margin: 0;
  max-width: 40em;
  font-size: 17px;
  line-height: 1.85;
  color: var(--steel);
}
.page-about .about-head__facts {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: 34px 0 0;
  padding: 0;
  list-style: none;
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  overflow: hidden;
}
.page-about .about-fact {
  background: var(--ink-2);
  padding: 16px 18px;
  display: flex;
  flex-direction: column;
  gap: 6px;
}
.page-about .about-fact__num {
  font-size: 20px;
  font-weight: 600;
  color: var(--white);
  letter-spacing: 0.04em;
}
.page-about .about-fact:first-child .about-fact__num {
  color: var(--amber);
}
.page-about .about-fact:last-child .about-fact__num {
  color: var(--teal);
}
.page-about .about-fact__label {
  font-size: 13px;
  color: var(--steel);
  line-height: 1.5;
}

/* ---------- 主体两栏 ---------- */
.page-about .about-layout {
  display: grid;
  gap: 30px;
  padding-top: 42px;
}

/* ---------- 左侧索引 ---------- */
.page-about .about-rail__label {
  margin: 0 0 10px;
  font-size: 12px;
  letter-spacing: 0.18em;
  color: var(--steel);
}
.page-about .about-rail__list {
  display: flex;
  gap: 8px;
  margin: 0;
  padding: 0 0 6px;
  list-style: none;
  overflow-x: auto;
  scrollbar-width: none;
}
.page-about .about-rail__list::-webkit-scrollbar {
  display: none;
}
.page-about .about-rail__link {
  display: inline-flex;
  align-items: baseline;
  gap: 9px;
  padding: 9px 13px;
  border: 1px solid var(--line);
  border-radius: 999px;
  font-size: 13.5px;
  line-height: 1.4;
  color: var(--steel);
  text-decoration: none;
  white-space: nowrap;
  transition: color 0.2s, border-color 0.2s, background 0.2s;
}
.page-about .about-rail__link .num {
  color: var(--amber);
  font-size: 12.5px;
}
.page-about .about-rail__link:hover,
.page-about .about-rail__link:focus-visible {
  color: var(--white);
  border-color: var(--amber);
}
.page-about .about-rail__link.is-active {
  color: var(--white);
  border-color: var(--red);
  background: rgba(255, 59, 92, 0.09);
  letter-spacing: 0.04em;
}
.page-about .about-rail__link.is-active .num {
  color: var(--red);
}

/* ---------- 纵向时间轴 ---------- */
.page-about .about-stream {
  position: relative;
  padding-left: var(--about-gutter);
}
.page-about .about-stream::before {
  content: "";
  position: absolute;
  left: var(--about-line);
  top: 8px;
  bottom: 40px;
  width: 1px;
  background: linear-gradient(180deg, var(--red), var(--amber) 42%, var(--teal));
  opacity: 0.5;
}
.page-about .about-stage {
  position: relative;
  padding-bottom: 52px;
}
.page-about .about-stage:last-child {
  padding-bottom: 0;
}
.page-about .about-stage::before {
  content: "";
  position: absolute;
  left: calc(-1 * var(--about-gutter));
  top: 10px;
  width: 11px;
  height: 11px;
  border-radius: 50%;
  background: var(--ink);
  border: 1px solid var(--amber);
  box-shadow: 0 0 0 4px rgba(255, 179, 71, 0.08);
  transition: border-color 0.35s, box-shadow 0.35s;
}
.page-about .about-stage.is-in::before {
  border-color: var(--teal);
  box-shadow: 0 0 0 5px rgba(47, 217, 179, 0.14);
}
.page-about .about-stage__meta {
  display: flex;
  align-items: center;
  gap: 12px;
  margin: 0 0 10px;
  font-size: 12.5px;
}
.page-about .about-stage__year {
  color: var(--amber);
  font-weight: 600;
  letter-spacing: 0.06em;
}
.page-about .about-stage__no {
  color: var(--steel);
  padding-left: 12px;
  border-left: 1px solid var(--line);
  letter-spacing: 0.08em;
}
.page-about .about-stage__title {
  margin: 0 0 16px;
  font-size: clamp(21px, 4.4vw, 30px);
  line-height: 1.35;
  font-weight: 700;
  letter-spacing: 0.01em;
  color: var(--white);
}
.page-about .about-stage__body p {
  margin: 0 0 16px;
  font-size: 16.5px;
  line-height: 1.85;
  color: var(--steel);
  max-width: 38em;
}
.page-about .about-stage__body p:last-child {
  margin-bottom: 0;
}
.page-about .about-stage__body a,
.page-about .about-inline-link a {
  color: var(--amber);
  text-decoration: none;
  border-bottom: 1px solid rgba(255, 179, 71, 0.4);
}
.page-about .about-stage__body a:hover,
.page-about .about-inline-link a:hover {
  border-bottom-color: var(--amber);
}
.page-about .about-inline-link {
  margin: 22px 0 0;
  font-size: 15px;
  line-height: 1.8;
  color: var(--steel);
}

/* ---------- 起步注释条 ---------- */
.page-about .about-note {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 16px;
  margin-top: 24px;
  padding: 15px 18px;
  border-left: 3px solid var(--red);
  background: var(--felt);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
}
.page-about .about-note__key {
  font-size: 12.5px;
  color: var(--red);
  letter-spacing: 0.08em;
}
.page-about .about-note__val {
  font-size: 14.5px;
  color: var(--white);
  line-height: 1.7;
}

/* ---------- 三次改版 ---------- */
.page-about .about-rewrites {
  margin: 26px 0 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 14px;
}
.page-about .about-rewrite {
  position: relative;
  padding: 20px 20px 20px 24px;
  background: var(--felt);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  transition: transform 0.25s, box-shadow 0.25s, border-color 0.25s;
}
.page-about .about-rewrite::before {
  content: "";
  position: absolute;
  left: 0;
  top: 18px;
  bottom: 18px;
  width: 2px;
  border-radius: 2px;
  background: linear-gradient(180deg, var(--amber), rgba(255, 179, 71, 0.1));
}
.page-about .about-rewrite:hover {
  transform: translateY(-2px);
  border-color: rgba(255, 179, 71, 0.45);
  box-shadow: 0 18px 40px -30px rgba(0, 0, 0, 0.9);
}
.page-about .about-rewrite__tag {
  margin: 0 0 8px;
  font-size: 12.5px;
  color: var(--amber);
  letter-spacing: 0.06em;
}
.page-about .about-rewrite__title {
  margin: 0 0 10px;
  font-size: 19px;
  font-weight: 700;
  line-height: 1.45;
  color: var(--white);
}
.page-about .about-rewrite__text {
  margin: 0;
  font-size: 15.5px;
  line-height: 1.85;
  color: var(--steel);
}

/* ---------- 图片 ---------- */
.page-about .about-shot {
  margin: 28px 0 0;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
  background: var(--felt);
}
.page-about .about-shot img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
}
.page-about .about-shot--wide img {
  aspect-ratio: 2 / 1;
}
.page-about .about-shot--photo img {
  aspect-ratio: 3 / 2;
}
.page-about .about-shot .media__cap {
  display: block;
  padding: 11px 16px;
  font-size: 12.5px;
  line-height: 1.6;
  color: var(--steel);
  border-top: 1px solid var(--line);
}

/* ---------- 兼容模式版本 ---------- */
.page-about .about-versions {
  margin: 30px 0 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
}
.page-about .about-version {
  display: grid;
  grid-template-columns: 56px minmax(0, 1fr);
  gap: 18px;
  padding: 20px 20px;
  background: var(--ink-2);
  transition: background 0.25s;
}
.page-about .about-version:hover {
  background: var(--felt);
}
.page-about .about-version--current {
  background: linear-gradient(96deg, rgba(255, 59, 92, 0.1), rgba(255, 179, 71, 0.05) 62%, transparent);
}
.page-about .about-version__no {
  margin: 0;
  font-size: 17px;
  font-weight: 600;
  letter-spacing: 0.08em;
  color: var(--teal);
}
.page-about .about-version--current .about-version__no {
  color: var(--red);
}
.page-about .about-version__title {
  margin: 0 0 8px;
  font-size: 17.5px;
  font-weight: 700;
  line-height: 1.45;
  color: var(--white);
}
.page-about .about-version__body p {
  margin: 0;
  font-size: 15.5px;
  line-height: 1.85;
  color: var(--steel);
}

/* ---------- 折叠面板 ---------- */
.page-about .about-disclosure {
  margin-top: 22px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--ink-2);
  overflow: hidden;
}
.page-about .about-disclosure .disclosure__summary {
  padding: 16px 20px;
  font-size: 15.5px;
  font-weight: 600;
  color: var(--white);
  cursor: pointer;
  list-style: none;
  position: relative;
}
.page-about .about-disclosure .disclosure__summary::-webkit-details-marker {
  display: none;
}
.page-about .about-disclosure .disclosure__summary::after {
  content: "+";
  position: absolute;
  right: 20px;
  top: 50%;
  transform: translateY(-50%);
  font-family: var(--font-mono);
  font-size: 18px;
  color: var(--amber);
}
.page-about .about-disclosure[open] .disclosure__summary::after {
  content: "–";
}
.page-about .about-disclosure .disclosure__summary:focus-visible {
  outline: 1px solid var(--amber);
  outline-offset: -2px;
}
.page-about .about-disclosure .disclosure__body {
  padding: 0 20px 20px;
  border-top: 1px solid var(--line);
}
.page-about .about-disclosure .disclosure__body p {
  margin: 16px 0 0;
  font-size: 15px;
  line-height: 1.85;
  color: var(--steel);
}

/* ---------- 团队 ---------- */
.page-about .about-teams {
  display: grid;
  gap: 14px;
  margin-top: 26px;
}
.page-about .about-team {
  padding: 20px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--felt);
  transition: transform 0.25s, border-color 0.25s;
}
.page-about .about-team:hover {
  transform: translateY(-2px);
  border-color: rgba(47, 217, 179, 0.4);
}
.page-about .about-team__no {
  margin: 0 0 10px;
  font-size: 12.5px;
  letter-spacing: 0.18em;
  color: var(--teal);
}
.page-about .about-team__name {
  margin: 0 0 10px;
  font-size: 18px;
  font-weight: 700;
  color: var(--white);
}
.page-about .about-team__text {
  margin: 0;
  font-size: 15px;
  line-height: 1.85;
  color: var(--steel);
}

/* ---------- 反馈流转 ---------- */
.page-about .about-flow {
  margin: 16px 0 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 12px;
}
.page-about .about-flow li {
  display: grid;
  grid-template-columns: 34px minmax(0, 1fr);
  gap: 12px;
  font-size: 15px;
  line-height: 1.8;
  color: var(--steel);
}
.page-about .about-flow .num {
  color: var(--amber);
  font-size: 14px;
  padding-top: 2px;
}

/* ---------- 城市引用 ---------- */
.page-about .about-quote {
  margin: 24px 0 0;
  padding: 20px 24px;
  border-left: 3px solid var(--teal);
  background: linear-gradient(96deg, rgba(47, 217, 179, 0.09), transparent 72%);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
}
.page-about .about-quote p {
  margin: 0;
  font-size: 19px;
  font-weight: 700;
  letter-spacing: 0.06em;
  color: var(--white);
}

/* ---------- 收尾面板 ---------- */
.page-about .about-panel {
  margin-top: 26px;
  padding: 24px 22px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: linear-gradient(120deg, rgba(255, 59, 92, 0.12), rgba(255, 179, 71, 0.06) 58%, transparent);
}
.page-about .about-panel__title {
  margin: 0 0 12px;
  font-size: 19px;
  font-weight: 700;
  color: var(--white);
}
.page-about .about-panel__text {
  margin: 0;
  font-size: 15.5px;
  line-height: 1.85;
  color: var(--steel);
  max-width: 34em;
}
.page-about .about-panel__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin: 20px 0 0;
}

/* ---------- 滚动进入 ---------- */
.page-about [data-reveal] {
  opacity: 1;
}
.page-about .js-reveal [data-reveal] {
  opacity: 0;
  transform: translateY(14px);
  transition: opacity 0.5s ease, transform 0.5s ease;
}
.page-about .js-reveal [data-reveal].is-in {
  opacity: 1;
  transform: none;
}

/* ---------- 中屏 ---------- */
@media (min-width: 680px) {
  .page-about .about-head__facts {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
  .page-about .about-teams {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
  .page-about .about-versions {
    gap: 1px;
  }
}

/* ---------- 桌面 ---------- */
@media (min-width: 1000px) {
  .page-about .about-layout {
    grid-template-columns: var(--about-rail-w) minmax(0, 1fr);
    gap: 54px;
  }
  .page-about .about-rail {
    position: sticky;
    top: calc(var(--header-h) + 26px);
    align-self: start;
  }
  .page-about .about-rail__list {
    flex-direction: column;
    gap: 2px;
    overflow: visible;
    padding-bottom: 0;
  }
  .page-about .about-rail__link {
    display: flex;
    justify-content: flex-start;
    border-color: transparent;
    border-radius: var(--radius-sm);
    padding: 10px 12px;
  }
  .page-about .about-rail__link .num {
    display: inline-block;
    min-width: 60px;
  }
  .page-about .about-stream {
    --about-gutter: 30px;
  }
  .page-about .about-head {
    padding-bottom: 48px;
  }
  .page-about .about-layout {
    padding-top: 52px;
  }
}

/* ---------- 关闭动效 ---------- */
@media (prefers-reduced-motion: reduce) {
  .page-about .js-reveal [data-reveal] {
    opacity: 1;
    transform: none;
    transition: none;
  }
  .page-about .about-rewrite:hover,
  .page-about .about-team:hover {
    transform: none;
  }
  .page-about .about-stage::before,
  .page-about .about-rail__link {
    transition: none;
  }
}
<<<END>>>