.page-about {
  --about-soft: rgba(11, 26, 21, 0.74);
  --about-grid-soft: rgba(216, 206, 188, 0.45);
  --about-block-gap: clamp(16px, 2.4vw, 28px);
  --about-section-y: clamp(34px, 5.4vw, 72px);
}

/* ---------- 开场声明 ---------- */
.page-about .about-hero {
  padding: clamp(24px, 4.5vw, 56px) 0 clamp(30px, 5vw, 64px);
  border-bottom: 1px solid var(--edge);
}

.page-about .about-hero__inner {
  border-left: 2px solid var(--ember);
  padding-left: clamp(16px, 2.6vw, 32px);
}

.page-about .about-hero__eyebrow {
  margin: 0 0 clamp(14px, 2vw, 22px);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--amber);
}

.page-about .about-hero__title {
  margin: 0;
  max-width: 20ch;
  font-family: var(--font-head);
  font-weight: 800;
  font-size: clamp(32px, 6.4vw, 72px);
  line-height: 1.08;
  letter-spacing: -0.01em;
  color: var(--paper);
}

.page-about .about-hero__lede {
  margin: clamp(18px, 3vw, 30px) 0 0;
  max-width: 46ch;
  font-size: clamp(15px, 1.3vw, 17.5px);
  line-height: 1.85;
  color: var(--mist);
}

.page-about .about-hero__facts {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: clamp(26px, 4vw, 46px) 0 0;
  padding: 0;
  background: var(--edge);
  border: 1px solid var(--edge);
}

.page-about .about-fact {
  background: var(--ink);
  padding: 15px 16px 17px;
}

.page-about .about-fact__key {
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--mist);
}

.page-about .about-fact__value {
  margin: 9px 0 0;
  font-family: var(--font-mono);
  font-size: clamp(22px, 3vw, 32px);
  line-height: 1;
  color: var(--cyan);
}

.page-about .about-fact__unit {
  margin-left: 5px;
  font-size: 0.48em;
  color: var(--mist);
}

/* ---------- 两栏骨架 ---------- */
.page-about .about-layout {
  display: grid;
  gap: clamp(20px, 3vw, 48px);
  padding-bottom: clamp(40px, 6vw, 88px);
}

.page-about .about-flow > .section {
  padding: var(--about-section-y) 0;
}

.page-about .about-flow > .section + .section {
  border-top: 1px solid var(--edge);
}

.page-about .about-flow > .about-sources {
  border-top-color: var(--paper-line);
}

.page-about .about-index {
  display: none;
}

.page-about .about-index__title {
  margin: 0 0 12px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.18em;
  color: var(--amber);
}

/* ---------- 时间带 ---------- */
.page-about .timeline__track {
  list-style: none;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  margin: clamp(20px, 3.4vw, 34px) 0 0;
  padding: 0;
  background: var(--edge);
  border-top: 1px solid var(--amber);
  border-bottom: 1px solid var(--amber);
}

.page-about .tl-node {
  background: var(--ink);
  padding: 20px 18px 22px;
  outline: none;
  transition: background-color var(--step) ease;
}

.page-about .tl-node:hover,
.page-about .tl-node:focus-visible {
  background: var(--pine);
}

.page-about .tl-node:focus-visible {
  box-shadow: inset 0 0 0 2px var(--cyan);
}

.page-about .tl-node__year {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(34px, 5vw, 54px);
  line-height: 1;
  color: var(--cyan);
}

.page-about .tl-node__label {
  display: block;
  margin-top: 10px;
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--amber);
}

.page-about .tl-node__note {
  max-height: 0;
  margin: 0;
  overflow: hidden;
  opacity: 0;
  font-size: 14px;
  line-height: 1.72;
  color: var(--mist);
  transition: max-height var(--step) ease, opacity var(--step) ease, margin-top var(--step) ease;
}

.page-about .tl-node:hover .tl-node__note,
.page-about .tl-node:focus-visible .tl-node__note {
  max-height: 180px;
  margin-top: 12px;
  opacity: 1;
}

/* ---------- 图 ---------- */
.page-about .media {
  margin: 0;
}

.page-about .media__frame {
  position: relative;
  overflow: hidden;
  border: 1px solid var(--edge);
}

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

.page-about .media__frame--about-map {
  aspect-ratio: 3 / 2;
}

.page-about .media__caption {
  margin-top: 10px;
  font-size: 13px;
  line-height: 1.7;
  color: var(--mist);
}

.page-about .about-figure {
  margin-top: clamp(24px, 3.6vw, 40px);
}

/* ---------- 日常运转 ---------- */
.page-about .about-daily__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--about-block-gap);
  margin-top: clamp(20px, 3.4vw, 34px);
}

.page-about .about-daily__left {
  display: grid;
  gap: var(--about-block-gap);
}

.page-about .num-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--edge);
  border: 1px solid var(--edge);
}

.page-about .num-cell {
  background: var(--pine);
  padding: 15px 14px 17px;
}

.page-about .num-cell__value {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(24px, 3.2vw, 36px);
  line-height: 1;
  color: var(--paper);
}

.page-about .num-cell__label {
  display: block;
  margin-top: 9px;
  font-size: 12px;
  line-height: 1.6;
  color: var(--mist);
}

.page-about .about-daily__figure {
  align-self: start;
}

.page-about .line-item {
  position: relative;
  padding: 15px 0 15px 42px;
  border-top: 1px solid var(--edge);
}

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

.page-about .line-item__num {
  position: absolute;
  left: 0;
  top: 18px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--amber);
}

.page-about .line-item__title {
  margin: 0;
  font-size: 16px;
  font-weight: 700;
  letter-spacing: 0.01em;
  color: var(--paper);
}

.page-about .line-item__text {
  margin: 8px 0 0;
  font-size: 14.5px;
  line-height: 1.78;
  color: var(--mist);
}

/* ---------- 数据来源（纸面展板） ---------- */
.page-about .about-sources {
  background-color: var(--paper);
  background-image:
    linear-gradient(var(--about-grid-soft) 1px, transparent 1px),
    linear-gradient(90deg, var(--about-grid-soft) 1px, transparent 1px);
  background-size: 64px 64px;
  background-position: -1px -1px;
  color: var(--ink);
}

.page-about .about-sources .section-head__index {
  color: var(--ember);
  border-color: var(--ember);
}

.page-about .about-sources .section-head__title {
  color: var(--ink);
}

.page-about .about-sources .section-head__note {
  color: var(--about-soft);
}

.page-about .hang-list {
  list-style: none;
  margin: clamp(16px, 2.6vw, 26px) 0 0;
  padding: 0;
  max-width: 62ch;
}

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

.page-about .hang-item:first-child {
  border-top: 1px solid var(--paper-line);
}

.page-about .hang-item__summary {
  display: flex;
  align-items: baseline;
  gap: 14px;
  padding: 16px 0;
  cursor: pointer;
  list-style: none;
  font-size: 15.5px;
  font-weight: 700;
  color: var(--ink);
  transition: color var(--step) ease;
}

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

.page-about .hang-item__summary::after {
  content: "+";
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: 16px;
  color: var(--ember);
}

.page-about .hang-item__summary:hover {
  color: var(--ember);
}

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

.page-about .hang-item__num {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--ember);
}

.page-about .hang-item__body {
  margin: 0 0 18px;
  padding-left: 32px;
  max-width: 56ch;
  font-size: 14.5px;
  line-height: 1.82;
  color: var(--about-soft);
}

/* ---------- 团队 ---------- */
.page-about .about-team__figure {
  margin: 0 0 clamp(22px, 3.4vw, 36px);
}

.page-about .team-rows {
  display: grid;
  gap: 1px;
  margin-top: clamp(18px, 2.8vw, 28px);
  background: var(--edge);
  border: 1px solid var(--edge);
}

.page-about .team-row {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 8px;
  padding: 16px 18px;
  background: var(--ink);
}

.page-about .team-row__key {
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.04em;
  color: var(--paper);
}

.page-about .team-row__num {
  font-size: clamp(24px, 3vw, 32px);
  font-weight: 400;
  color: var(--cyan);
}

.page-about .team-row__desc {
  font-size: 14.5px;
  line-height: 1.78;
  color: var(--mist);
}

/* ---------- 合作生态 ---------- */
.page-about .about-eco__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(22px, 3.4vw, 44px);
  margin-top: clamp(20px, 3.4vw, 34px);
  align-items: center;
}

.page-about .about-eco__svg {
  display: block;
  width: 100%;
  max-width: 380px;
  height: auto;
  margin: 0 auto;
}

.page-about .eco-link {
  stroke: var(--edge);
  stroke-width: 1;
}

.page-about .eco-hub {
  fill: var(--ember);
}

.page-about .eco-hub-text {
  fill: var(--paper);
  font-family: var(--font-mono);
  font-size: 16px;
  letter-spacing: 0.06em;
}

.page-about .eco-node circle {
  fill: var(--pine);
  stroke: var(--edge);
  stroke-width: 1;
  transition: fill var(--step) ease, stroke var(--step) ease;
}

.page-about .eco-node text {
  fill: var(--cyan);
  font-family: var(--font-mono);
  font-size: 16px;
  transition: fill var(--step) ease;
}

.page-about .eco-node:hover circle {
  fill: var(--amber);
  stroke: var(--amber);
}

.page-about .eco-node:hover text {
  fill: var(--ink);
}

.page-about .eco-list {
  list-style: none;
  display: grid;
  gap: 14px;
  margin: 0;
  padding: 0;
}

.page-about .eco-item {
  border-left: 2px solid var(--edge);
  padding-left: 14px;
  transition: border-color var(--step) ease;
}

.page-about .eco-item:hover {
  border-color: var(--amber);
}

.page-about .eco-item__head {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 12px;
  font-size: 15px;
  font-weight: 700;
  color: var(--paper);
}

.page-about .eco-item__num {
  font-family: var(--font-mono);
  font-size: 18px;
  color: var(--cyan);
}

.page-about .eco-item__text {
  margin: 7px 0 0;
  font-size: 14px;
  line-height: 1.75;
  color: var(--mist);
}

/* ---------- 选择理由 ---------- */
.page-about .why-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  margin-top: clamp(20px, 3.4vw, 34px);
  background: var(--edge);
  border: 1px solid var(--edge);
}

.page-about .why-cell {
  background: var(--ink);
  padding: 20px 18px 22px;
}

.page-about .why-cell__title {
  margin: 0;
  font-size: 16px;
  font-weight: 700;
  color: var(--paper);
}

.page-about .why-cell__text {
  margin: 9px 0 0;
  font-size: 14.5px;
  line-height: 1.78;
  color: var(--mist);
}

.page-about .note-official {
  margin: clamp(22px, 3.2vw, 34px) 0 0;
}

/* ---------- 合作入口 ---------- */
.page-about .about-cta__title {
  margin: 0;
  max-width: 22ch;
  font-family: var(--font-head);
  font-weight: 800;
  font-size: clamp(26px, 3.6vw, 44px);
  line-height: 1.14;
  color: var(--paper);
}

.page-about .about-cta__text {
  margin: clamp(14px, 2.2vw, 22px) 0 0;
  max-width: 48ch;
  font-size: 15.5px;
  line-height: 1.85;
  color: var(--mist);
}

.page-about .about-cta__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: clamp(20px, 3vw, 30px);
}

/* ---------- 断点 ---------- */
@media (min-width: 680px) {
  .page-about .about-hero__facts {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

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

  .page-about .team-row {
    grid-template-columns: minmax(0, 190px) minmax(0, 1fr);
    align-items: baseline;
    gap: 18px;
  }

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

@media (min-width: 900px) {
  .page-about .about-daily__grid {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1.05fr);
    gap: clamp(24px, 3.4vw, 46px);
  }

  .page-about .about-eco__grid {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1.05fr);
  }
}

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

  .page-about .about-layout {
    grid-template-columns: minmax(0, 1fr) 176px;
    align-items: start;
  }

  .page-about .about-index {
    display: block;
    position: sticky;
    top: 120px;
    padding-top: var(--about-section-y);
  }

  .page-about .side-index__link {
    display: block;
    padding: 7px 0 7px 12px;
    border-left: 1px solid var(--edge);
    font-size: 13px;
    color: var(--mist);
    text-decoration: none;
    transition: color var(--step) ease, border-color var(--step) ease;
  }

  .page-about .side-index__link:hover,
  .page-about .side-index__link:focus-visible {
    color: var(--paper);
    border-left-color: var(--amber);
  }

  .page-about .side-index__link[data-active="true"] {
    color: var(--cyan);
    border-left-color: var(--cyan);
  }
}

@media (min-width: 1280px) {
  .page-about .about-hero__lede {
    max-width: 52ch;
  }
}
<<<END>>>

<<<END>>>