.page-about {
  background: var(--paper);
  color: var(--ink);
  font-family: var(--font-body);
  padding-bottom: clamp(56px, 8vw, 112px);
}

.page-about .num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  letter-spacing: 0.01em;
}

/* ---------- 首屏 ---------- */
.page-about .about-head {
  padding-top: clamp(24px, 4vw, 44px);
  padding-bottom: clamp(28px, 5vw, 56px);
}

.page-about .about-eyebrow {
  display: inline-flex;
  align-items: center;
  margin: clamp(18px, 3vw, 30px) 0 0;
  padding: 6px 14px;
  border-radius: var(--radius-pill);
  background: var(--teal-mist);
  border: 1px solid rgba(15, 110, 127, 0.2);
  color: var(--teal-deep);
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: 0.12em;
}

.page-about .about-h1 {
  margin: clamp(16px, 3vw, 26px) 0 0;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(2rem, 6.6vw, 4.2rem);
  line-height: 1.04;
  letter-spacing: -0.02em;
  max-width: 19ch;
  color: var(--ink);
}

.page-about .about-lede {
  margin: clamp(16px, 2.6vw, 26px) 0 0;
  max-width: 40em;
  font-size: clamp(15.5px, 1.7vw, 18px);
  line-height: 1.78;
  color: var(--ink-soft);
}

.page-about .about-stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 10px;
  margin-top: clamp(24px, 4vw, 40px);
}

.page-about .about-stat {
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding: 14px 16px;
  border-radius: var(--radius-md);
  background: var(--paper-3);
  border: 1px solid var(--ink-line);
}

.page-about .about-stat:first-child {
  background: var(--teal);
  border-color: transparent;
  color: var(--paper-3);
}

.page-about .about-stat__value {
  font-size: clamp(1.5rem, 3.2vw, 2.1rem);
  font-weight: 700;
  line-height: 1;
}

.page-about .about-stat__label {
  font-size: 13px;
  line-height: 1.5;
  opacity: 0.72;
}

/* ---------- 主体骨架 ---------- */
.page-about .about-body {
  display: grid;
  gap: clamp(28px, 4vw, 52px);
}

.page-about .about-flow {
  display: flex;
  flex-direction: column;
  gap: clamp(48px, 8vw, 104px);
  min-width: 0;
}

/* ---------- 坐标索引 ---------- */
.page-about .about-index {
  order: -1;
  min-width: 0;
}

.page-about .about-index__title {
  margin: 0 0 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.18em;
  color: var(--ink-soft);
}

.page-about .about-index__list {
  list-style: none;
  margin: 0;
  padding: 0 0 4px;
  display: flex;
  gap: 8px;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
}

.page-about .about-index__item {
  flex: none;
}

.page-about .about-index__link {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 14px;
  border-radius: var(--radius-pill);
  background: var(--paper-3);
  border: 1px solid var(--ink-line);
  color: var(--teal-deep);
  text-decoration: none;
  font-size: 14px;
  white-space: nowrap;
  transition: background 0.18s ease, color 0.18s ease;
}

.page-about .about-index__link .num {
  font-size: 12px;
  color: var(--gold);
}

.page-about .about-index__link[data-active="true"] {
  background: var(--teal);
  border-color: transparent;
  color: var(--paper-3);
}

.page-about .about-index__link[data-active="true"] .num {
  color: var(--gold-soft);
}

/* ---------- 画板 ---------- */
.page-about .about-panel {
  position: relative;
  min-width: 0;
}

.page-about .about-panel__head {
  display: flex;
  align-items: baseline;
  gap: 14px;
  margin-bottom: clamp(16px, 2.4vw, 26px);
}

.page-about .about-panel__no {
  flex: none;
  padding: 5px 12px;
  border-radius: var(--radius-pill);
  background: var(--teal);
  color: var(--paper-3);
  font-size: 13px;
  letter-spacing: 0.08em;
}

.page-about .about-panel__title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(1.45rem, 3.8vw, 2.35rem);
  line-height: 1.16;
  letter-spacing: -0.01em;
  color: var(--ink);
}

.page-about .about-panel__title::before {
  content: "";
  display: block;
  width: 42px;
  height: 3px;
  margin-bottom: 12px;
  border-radius: 2px;
  background: var(--gold);
}

.page-about .about-panel p {
  margin: 0 0 14px;
  max-width: 36em;
  font-size: clamp(15px, 1.5vw, 17px);
  line-height: 1.78;
  color: var(--ink-soft);
}

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

.page-about .about-panel .about-lead {
  font-size: clamp(16px, 1.8vw, 19px);
  color: var(--ink);
  max-width: 32em;
}

.page-about .about-link {
  color: var(--teal-deep);
  text-decoration: none;
  border-bottom: 2px solid var(--gold-soft);
  transition: border-color 0.18s ease;
}

.page-about .about-link:hover,
.page-about .about-link:focus-visible {
  border-bottom-color: var(--gold);
}

/* ---------- 标签 ---------- */
.page-about .about-tags {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 18px 0 0;
  padding: 0;
}

.page-about .about-tag {
  padding: 6px 14px;
  border-radius: var(--radius-pill);
  background: var(--teal-mist);
  border: 1px solid rgba(15, 110, 127, 0.16);
  color: var(--teal-deep);
  font-family: var(--font-mono);
  font-size: 13px;
}

/* ---------- 图片 ---------- */
.page-about .about-figure {
  margin: 0 0 clamp(20px, 3vw, 32px);
}

.page-about .about-figure__img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  border-radius: var(--radius-lg);
  object-fit: cover;
  background: var(--paper-2);
}

.page-about .about-figure__cap {
  margin-top: 10px;
  font-family: var(--font-mono);
  font-size: 12.5px;
  line-height: 1.6;
  color: var(--ink-soft);
}

/* ---------- 四步阶梯 ---------- */
.page-about .about-gates {
  list-style: none;
  margin: clamp(20px, 3vw, 30px) 0 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.page-about .about-gate {
  display: grid;
  grid-template-columns: 38px minmax(0, 1fr);
  grid-template-areas:
    "no title"
    "no time"
    "no desc";
  gap: 4px 14px;
  padding: clamp(16px, 3vw, 24px);
  border-radius: var(--radius-lg);
  background: var(--paper-3);
  border: 1px solid var(--ink-line);
}

.page-about .about-gate__no {
  grid-area: no;
  display: grid;
  place-items: center;
  width: 36px;
  height: 36px;
  border-radius: var(--radius-pill);
  background: var(--teal-deep);
  color: var(--paper-3);
  font-size: 14px;
  font-weight: 700;
}

.page-about .about-gate:nth-child(even) .about-gate__no {
  background: var(--gold);
  color: var(--ink);
}

.page-about .about-gate__title {
  grid-area: title;
  margin: 0;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(1.05rem, 2.2vw, 1.3rem);
  letter-spacing: -0.01em;
  color: var(--ink);
}

.page-about .about-gate__time {
  grid-area: time;
  justify-self: start;
  padding: 4px 10px;
  border-radius: var(--radius-pill);
  background: var(--gold-soft);
  color: var(--ink);
  font-size: 12.5px;
  white-space: nowrap;
}

.page-about .about-gate__desc {
  grid-area: desc;
  margin: 6px 0 0;
  font-size: 15px;
  line-height: 1.72;
  color: var(--ink-soft);
}

/* ---------- 团队点阵 ---------- */
.page-about .about-team {
  display: grid;
  gap: clamp(18px, 3vw, 30px);
  margin-top: clamp(20px, 3vw, 30px);
}

.page-about .about-dots {
  margin: 0;
  padding: clamp(16px, 3vw, 26px);
  border-radius: var(--radius-lg);
  background: var(--paper-3);
  border: 1px solid var(--ink-line);
}

.page-about .about-dots svg {
  display: block;
  width: 100%;
  height: auto;
  max-width: 460px;
}

.page-about .about-dot circle {
  fill: var(--teal);
  transition: opacity 0.18s ease;
}

.page-about .about-dot--edit circle {
  fill: var(--teal-deep);
}

.page-about .about-dot--data circle {
  fill: var(--gold);
}

.page-about .about-dot--collab circle {
  fill: var(--gold-soft);
}

.page-about .about-dot:hover circle {
  opacity: 0.5;
}

.page-about .about-legend {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.page-about .about-legend__item {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 12px 16px;
  border-radius: var(--radius-md);
  background: var(--paper-3);
  border: 1px solid var(--ink-line);
  font-size: 15px;
  color: var(--ink);
}

.page-about .about-legend__dot {
  flex: none;
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--teal);
}

.page-about .about-legend__dot--edit {
  background: var(--teal-deep);
}

.page-about .about-legend__dot--data {
  background: var(--gold);
}

.page-about .about-legend__dot--collab {
  background: var(--gold-soft);
}

.page-about .about-legend__name {
  flex: 1;
  min-width: 0;
}

.page-about .about-legend__count {
  font-size: 18px;
  font-weight: 700;
  color: var(--teal-deep);
}

/* ---------- 分栏 ---------- */
.page-about .about-split {
  display: grid;
  gap: clamp(20px, 3vw, 36px);
  align-items: start;
}

.page-about .about-split__media {
  min-width: 0;
}

.page-about .about-split__text {
  min-width: 0;
}

/* ---------- 时间线 ---------- */
.page-about .about-line {
  list-style: none;
  margin: clamp(20px, 3vw, 34px) 0 0;
  padding: 0 0 14px;
  display: flex;
  gap: clamp(16px, 3vw, 30px);
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  scroll-snap-type: x mandatory;
}

.page-about .about-line__item {
  position: relative;
  flex: 0 0 min(250px, 76vw);
  scroll-snap-align: start;
  padding-top: 46px;
  min-width: 0;
}

.page-about .about-line__item::before {
  content: "";
  position: absolute;
  top: 15px;
  left: 0;
  width: 100%;
  height: 2px;
  background: linear-gradient(90deg, var(--teal), var(--gold));
}

.page-about .about-line__item::after {
  content: "";
  position: absolute;
  top: 9px;
  left: 0;
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: var(--paper);
  border: 3px solid var(--teal);
}

.page-about .about-line__year {
  display: block;
  font-size: clamp(1.45rem, 3.4vw, 2rem);
  font-weight: 700;
  line-height: 1;
  color: var(--teal-deep);
}

.page-about .about-line__title {
  margin: 8px 0 10px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 1.08rem;
  letter-spacing: -0.01em;
  color: var(--ink);
}

.page-about .about-line__more summary {
  cursor: pointer;
  list-style: none;
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: 0.04em;
  color: var(--gold);
  padding: 4px 0;
}

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

.page-about .about-line__more summary::before {
  content: "＋ ";
}

.page-about .about-line__more[open] summary::before {
  content: "－ ";
}

.page-about .about-line__more p {
  margin: 8px 0 0;
  font-size: 14.5px;
  line-height: 1.72;
  color: var(--ink-soft);
}

/* ---------- 收尾 ---------- */
.page-about .about-cta {
  padding: clamp(24px, 5vw, 48px);
  border-radius: var(--radius-lg);
  background: var(--ink);
  color: var(--paper);
}

.page-about .about-cta__title {
  margin: 0 0 12px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(1.35rem, 3vw, 2rem);
  letter-spacing: -0.01em;
  color: var(--paper);
}

.page-about .about-cta__text {
  margin: 0 0 22px;
  max-width: 36em;
  font-size: 16px;
  line-height: 1.78;
  color: rgba(244, 239, 228, 0.78);
}

.page-about .about-cta__links {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.page-about .about-btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 11px 20px;
  border-radius: var(--radius-pill);
  border: 1px solid transparent;
  font-size: 15px;
  font-weight: 600;
  text-decoration: none;
  transition: background 0.18s ease, color 0.18s ease, border-color 0.18s ease;
}

.page-about .about-btn--gold {
  background: var(--gold);
  color: var(--ink);
}

.page-about .about-btn--gold:hover,
.page-about .about-btn--gold:focus-visible {
  background: var(--gold-soft);
}

.page-about .about-btn--line {
  background: transparent;
  color: var(--paper);
  border-color: rgba(244, 239, 228, 0.4);
}

.page-about .about-btn--line:hover,
.page-about .about-btn--line:focus-visible {
  background: rgba(244, 239, 228, 0.12);
  border-color: rgba(244, 239, 228, 0.7);
}

/* ---------- 断点 ---------- */
@media (min-width: 600px) {
  .page-about .about-stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .about-gate {
    grid-template-columns: 40px minmax(0, 1fr) auto;
    grid-template-areas:
      "no title time"
      "no desc desc";
    gap: 6px 16px;
  }

  .page-about .about-gate__time {
    justify-self: end;
    align-self: start;
  }
}

@media (min-width: 720px) {
  .page-about .about-gate:nth-child(2) {
    margin-left: 24px;
  }

  .page-about .about-gate:nth-child(3) {
    margin-left: 48px;
  }

  .page-about .about-gate:nth-child(4) {
    margin-left: 72px;
  }
}

@media (min-width: 860px) {
  .page-about .about-split {
    grid-template-columns: minmax(0, 1.15fr) minmax(0, 0.85fr);
  }

  .page-about .about-split--rev {
    grid-template-columns: minmax(0, 0.85fr) minmax(0, 1.15fr);
  }

  .page-about .about-team {
    grid-template-columns: minmax(0, 1.1fr) minmax(0, 0.9fr);
    align-items: center;
  }
}

@media (min-width: 980px) {
  .page-about .about-body {
    grid-template-columns: minmax(0, 1fr) 208px;
    align-items: start;
    gap: clamp(32px, 4vw, 64px);
  }

  .page-about .about-index {
    order: 0;
    position: sticky;
    top: 104px;
  }

  .page-about .about-index__list {
    flex-direction: column;
    gap: 2px;
    overflow: visible;
    padding-bottom: 0;
  }

  .page-about .about-index__link {
    width: 100%;
    border: none;
    border-radius: var(--radius-sm);
    background: transparent;
    padding: 9px 12px;
    white-space: normal;
    font-size: 14.5px;
    color: var(--ink-soft);
  }

  .page-about .about-index__link:hover,
  .page-about .about-index__link:focus-visible {
    background: var(--paper-2);
    color: var(--teal-deep);
  }

  .page-about .about-index__link[data-active="true"] {
    background: var(--teal-mist);
    color: var(--teal-deep);
  }

  .page-about .about-index__link[data-active="true"] .num {
    color: var(--gold);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-dot circle {
    transition: none;
  }

  .page-about .about-index__link,
  .page-about .about-btn,
  .page-about .about-link {
    transition: none;
  }
}
<<<END>>>