.page-about {
  --about-track: 11rem;
  background: var(--ink-900);
  color: var(--text-light);
}

.page-about .about-link {
  color: inherit;
  text-decoration: underline;
  text-decoration-thickness: 1px;
  text-underline-offset: .22em;
  text-decoration-color: currentColor;
  transition: color .18s var(--ease), text-decoration-color .18s var(--ease);
}

.page-about .section--ink .about-link:hover,
.page-about .section--ink .about-link:focus-visible {
  color: var(--gold-soft);
  text-decoration-color: var(--gold-soft);
}

.page-about .section--paper .about-link:hover,
.page-about .section--paper .about-link:focus-visible {
  color: #7A5E1C;
  text-decoration-thickness: 2px;
}

/* ---------- 首屏 ---------- */

.page-about .about-hero {
  position: relative;
  overflow: hidden;
  background: var(--ink-900);
  padding-block-start: clamp(1.75rem, 4vw, 3rem);
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image:
    linear-gradient(to right, rgba(42, 74, 98, .38) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(42, 74, 98, .38) 1px, transparent 1px);
  background-size: 64px 64px;
  -webkit-mask-image: radial-gradient(ellipse at 72% 26%, #000 0%, transparent 68%);
  mask-image: radial-gradient(ellipse at 72% 26%, #000 0%, transparent 68%);
}

.page-about .about-hero__inner {
  position: relative;
  z-index: 1;
  display: grid;
  gap: clamp(1.75rem, 4vw, 3.25rem);
  align-items: center;
  padding-block-end: clamp(2rem, 5vw, 3.5rem);
}

.page-about .about-hero__title {
  margin: .6rem 0 0;
  font-family: var(--font-display);
  font-size: clamp(2.1rem, 7vw, 3.9rem);
  line-height: 1.06;
  letter-spacing: .02em;
  color: var(--text-light);
}

.page-about .about-hero__lede {
  margin: 1rem 0 0;
  max-width: 34rem;
  color: var(--muted);
  line-height: 1.78;
}

.page-about .about-hero__facts {
  list-style: none;
  margin: 1.9rem 0 0;
  padding: 1.25rem 0 0;
  border-top: 1px solid var(--line);
  display: grid;
  gap: .9rem;
  grid-template-columns: repeat(auto-fit, minmax(8.5rem, 1fr));
}

.page-about .about-hero__facts li {
  display: flex;
  flex-direction: column;
  gap: .2rem;
}

.page-about .about-hero__num {
  font-family: var(--font-mono);
  font-size: clamp(1.4rem, 3.4vw, 1.9rem);
  font-weight: 700;
  line-height: 1;
  color: var(--gold);
  letter-spacing: -.01em;
}

.page-about .about-hero__cap {
  font-size: .8rem;
  line-height: 1.5;
  color: var(--muted);
}

.page-about .about-hero__media {
  margin: 0;
  position: relative;
  border: 1px solid var(--line);
  background: var(--ink-700);
  box-shadow: 0 24px 60px -32px rgba(0, 0, 0, .9);
}

.page-about .about-hero__media::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  box-shadow: inset 0 0 0 1px rgba(200, 162, 74, .16);
}

.page-about .about-hero__media img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 16 / 9;
  object-fit: cover;
}

/* 章节预览条 */

.page-about .about-toc {
  position: relative;
  z-index: 1;
  background: var(--ink-700);
  border-top: 1px solid var(--line);
}

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

.page-about .about-toc__list > li {
  flex: 0 0 auto;
}

.page-about .about-toc__link {
  display: flex;
  align-items: baseline;
  gap: .5rem;
  padding: .95rem clamp(1rem, 3vw, 1.6rem);
  border-right: 1px solid var(--line);
  font-size: .85rem;
  letter-spacing: .04em;
  color: var(--muted);
  text-decoration: none;
  white-space: nowrap;
  transition: color .18s var(--ease), background-color .18s var(--ease), box-shadow .18s var(--ease);
}

.page-about .about-toc__num {
  font-family: var(--font-mono);
  font-size: .75rem;
  color: var(--gold);
  opacity: .7;
  transition: opacity .18s var(--ease);
}

.page-about .about-toc__link:hover,
.page-about .about-toc__link:focus-visible {
  color: var(--text-light);
  background: rgba(79, 209, 197, .09);
  outline: none;
}

.page-about .about-toc__link:hover .about-toc__num,
.page-about .about-toc__link:focus-visible .about-toc__num {
  opacity: 1;
}

.page-about .about-toc__link[aria-current="true"] {
  color: var(--gold-soft);
  box-shadow: inset 0 -2px 0 var(--gold);
}

.page-about .about-toc__link[aria-current="true"] .about-toc__num {
  opacity: 1;
}

/* ---------- 章节骨架 ---------- */

.page-about .about-chapter__grid {
  display: grid;
  gap: 1.1rem;
}

.page-about .about-chapter__index {
  display: flex;
  align-items: baseline;
  gap: .85rem;
}

.page-about .about-num {
  font-family: var(--font-mono);
  font-size: clamp(2.75rem, 8vw, 5rem);
  font-weight: 700;
  line-height: .82;
  letter-spacing: -.03em;
  color: rgba(200, 162, 74, .3);
}

.page-about .section--paper .about-num {
  color: rgba(150, 112, 32, .38);
}

.page-about .about-chapter__label {
  font-family: var(--font-mono);
  font-size: .72rem;
  letter-spacing: .22em;
  text-transform: uppercase;
  color: var(--gold);
}

.page-about .section--paper .about-chapter__label {
  color: #7A5E1C;
}

.page-about .about-chapter__title {
  margin: 0 0 1.1rem;
  font-size: clamp(1.5rem, 4vw, 2.3rem);
  line-height: 1.2;
}

.page-about .about-chapter__body > p {
  max-width: 38rem;
  line-height: 1.8;
}

.page-about .about-pull {
  margin: 1.8rem 0 0;
  max-width: 38rem;
  padding: 1rem 1.25rem;
  border-left: 2px solid var(--gold);
  background: rgba(200, 162, 74, .08);
  font-size: .95rem;
  line-height: 1.75;
}

.page-about .about-note {
  margin-top: 1.6rem;
  max-width: 38rem;
  font-size: .9rem;
  line-height: 1.75;
  color: var(--muted);
}

.page-about .section--paper .about-note {
  color: #6B5C48;
}

/* ---------- 三条主张 ---------- */

.page-about .about-principles {
  list-style: none;
  margin: 2rem 0 0;
  padding: 0;
  border-top: 1px solid var(--line);
}

.page-about .about-principle {
  display: grid;
  gap: .4rem;
  padding: 1.5rem 0;
  border-bottom: 1px solid var(--line);
}

.page-about .about-principle__key {
  font-family: var(--font-mono);
  font-size: 1.15rem;
  letter-spacing: .12em;
  color: var(--gold);
}

.page-about .about-principle__text h3 {
  margin: 0 0 .5rem;
  font-size: 1.05rem;
  line-height: 1.5;
  color: var(--text-light);
}

.page-about .about-principle__text p {
  margin: 0;
  max-width: 36rem;
  font-size: .93rem;
  line-height: 1.8;
  color: var(--muted);
}

/* ---------- 能力矩阵 ---------- */

.page-about .about-figure {
  margin: 1.9rem 0 0;
  border: 1px solid var(--line);
  background: var(--ink-700);
  position: relative;
}

.page-about .section--paper .about-figure {
  background: var(--paper-2);
  border-color: rgba(36, 28, 20, .18);
}

.page-about .about-figure img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
  aspect-ratio: 3 / 2;
}

.page-about .about-figure--wide img {
  aspect-ratio: 2 / 1;
}

.page-about .about-figure figcaption {
  padding: .7rem 1rem;
  font-size: .78rem;
  line-height: 1.6;
  color: var(--muted);
  border-top: 1px solid var(--line);
}

.page-about .section--paper .about-figure figcaption {
  color: #6B5C48;
  border-top-color: rgba(36, 28, 20, .15);
}

.page-about .about-ability {
  margin-top: 1.9rem;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  border-top: 1px solid rgba(36, 28, 20, .2);
  border-left: 1px solid rgba(36, 28, 20, .2);
}

.page-about .about-ability__cell {
  padding: 1.35rem 1.15rem 1.6rem;
  border-right: 1px solid rgba(36, 28, 20, .2);
  border-bottom: 1px solid rgba(36, 28, 20, .2);
  transition: background-color .18s var(--ease);
}

.page-about .about-ability__cell::before {
  content: "";
  display: block;
  width: 26px;
  height: 2px;
  margin-bottom: 1rem;
  background: var(--cyan);
  transition: width .18s var(--ease), background-color .18s var(--ease);
}

.page-about .about-ability__title {
  margin: 0 0 .4rem;
  font-size: 1.05rem;
  letter-spacing: .04em;
}

.page-about .about-ability__metric {
  margin: 0 0 .7rem;
  font-family: var(--font-mono);
  font-size: .74rem;
  line-height: 1.6;
  color: #7A5E1C;
}

.page-about .about-ability__text {
  margin: 0;
  font-size: .9rem;
  line-height: 1.8;
  color: #4A4034;
  transition: color .18s var(--ease);
}

/* ---------- 演进节点 ---------- */

.page-about .about-yearnav {
  margin-top: 1.9rem;
  display: flex;
  flex-wrap: wrap;
  gap: .5rem;
}

.page-about .about-yearnav__item {
  display: inline-block;
  padding: .35rem .7rem;
  border: 1px solid var(--line);
  font-family: var(--font-mono);
  font-size: .78rem;
  letter-spacing: .08em;
  color: var(--muted);
  text-decoration: none;
  transition: color .18s var(--ease), border-color .18s var(--ease), background-color .18s var(--ease);
}

.page-about .about-yearnav__item:hover,
.page-about .about-yearnav__item:focus-visible {
  color: var(--ink-900);
  background: var(--gold);
  border-color: var(--gold);
  outline: none;
}

.page-about .about-yearnav__item[aria-current="true"] {
  color: var(--gold-soft);
  border-color: var(--gold);
  box-shadow: inset 2px 0 0 var(--gold);
}

.page-about .about-band {
  margin-top: 1.5rem;
  overflow-x: auto;
  overscroll-behavior-x: contain;
  scrollbar-width: thin;
  padding-bottom: .75rem;
  -webkit-mask-image: linear-gradient(to right, #000 0, #000 calc(100% - 2.5rem), transparent 100%);
  mask-image: linear-gradient(to right, #000 0, #000 calc(100% - 2.5rem), transparent 100%);
}

.page-about .about-band:focus-visible {
  outline: 2px solid var(--gold-soft);
  outline-offset: 4px;
}

.page-about .about-band__track {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  min-width: max-content;
}

.page-about .about-node {
  flex: 0 0 auto;
  width: min(15.5rem, 80vw);
  padding: .95rem 1.4rem 0 0;
  margin-right: 1.4rem;
  border-top: 1px solid var(--line);
  position: relative;
}

.page-about .about-node::before {
  content: "";
  position: absolute;
  top: -4px;
  left: 0;
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--cyan);
  transition: background-color .18s var(--ease), box-shadow .18s var(--ease);
}

.page-about .about-node:target::before {
  background: var(--gold);
  box-shadow: 0 0 0 4px rgba(200, 162, 74, .22);
}

.page-about .about-node__year {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(1.5rem, 3.2vw, 2.1rem);
  font-weight: 700;
  line-height: 1;
  color: var(--gold);
  margin-bottom: .7rem;
  transition: color .18s var(--ease);
}

.page-about .about-node:target .about-node__year {
  color: var(--gold-soft);
}

.page-about .about-node__title {
  margin: 0 0 .5rem;
  font-size: .98rem;
  line-height: 1.5;
}

.page-about .about-node__text {
  margin: 0;
  font-size: .88rem;
  line-height: 1.8;
  color: var(--muted);
}

/* ---------- 团队协作 ---------- */

.page-about .about-crews {
  margin: 1.9rem 0 0;
  display: grid;
  gap: 0;
  border-top: 1px solid rgba(36, 28, 20, .2);
}

.page-about .about-crew {
  padding: 1.25rem 0;
  border-bottom: 1px solid rgba(36, 28, 20, .2);
}

.page-about .about-crew dt {
  font-size: 1rem;
  letter-spacing: .05em;
  color: var(--ink-brown);
  margin-bottom: .4rem;
  padding-left: .75rem;
  border-left: 2px solid var(--gold);
}

.page-about .about-crew dd {
  margin: 0;
  font-size: .9rem;
  line-height: 1.8;
  color: #4A4034;
}

.page-about .about-subtitle {
  margin: 2.2rem 0 0;
  font-size: 1.1rem;
  line-height: 1.5;
}

.page-about .about-flow {
  margin: 1.1rem 0 0;
  padding: 0 0 0 1.35rem;
  max-width: 38rem;
  counter-reset: none;
}

.page-about .about-flow li {
  position: relative;
  padding: .55rem 0 .55rem .1rem;
  font-size: .92rem;
  line-height: 1.8;
  color: #4A4034;
}

.page-about .about-flow li::marker {
  color: var(--gold);
  font-family: var(--font-mono);
}

/* ---------- 覆盖范围 ---------- */

.page-about .about-reach {
  list-style: none;
  margin: 1.9rem 0 0;
  padding: 0;
  display: grid;
  gap: 0;
  border-top: 1px solid var(--line);
}

.page-about .about-reach li {
  display: grid;
  gap: .2rem;
  padding: 1.05rem 0;
  border-bottom: 1px solid var(--line);
}

.page-about .about-reach__num {
  font-family: var(--font-mono);
  font-size: 1.5rem;
  font-weight: 700;
  line-height: 1;
  color: var(--gold);
}

.page-about .about-reach__cap {
  font-size: .88rem;
  line-height: 1.7;
  color: var(--muted);
}

/* ---------- 收尾能力带 ---------- */

.page-about .about-closing {
  background: var(--ink-700);
  border-top: 8px solid var(--gold);
  padding-block: clamp(2.5rem, 6vw, 4.5rem);
}

.page-about .about-closing__title {
  margin: .7rem 0 0;
  font-size: clamp(1.5rem, 4vw, 2.2rem);
  line-height: 1.25;
}

.page-about .about-closing__items {
  list-style: none;
  margin: 1.8rem 0 0;
  padding: 1.2rem 0 0;
  border-top: 1px solid var(--line);
  display: flex;
  flex-wrap: wrap;
  gap: .6rem 2rem;
}

.page-about .about-closing__items li {
  position: relative;
  padding-left: .95rem;
  font-size: .9rem;
  color: var(--text-light);
}

.page-about .about-closing__items li::before {
  content: "";
  position: absolute;
  left: 0;
  top: .58em;
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: var(--cyan);
}

.page-about .about-closing__actions {
  margin-top: 1.9rem;
  display: flex;
  flex-wrap: wrap;
  gap: .8rem;
}

.page-about .about-closing__btn {
  text-decoration: none;
}

.page-about .about-closing__hint {
  margin: 1.2rem 0 0;
  font-size: .86rem;
  color: var(--muted);
}

/* ---------- 响应式 ---------- */

@media (min-width: 640px) {
  .page-about .about-ability {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .page-about .about-crew {
    display: grid;
    grid-template-columns: 9rem minmax(0, 1fr);
    gap: 1.25rem;
    align-items: start;
  }

  .page-about .about-crew dt {
    margin-bottom: 0;
  }

  .page-about .about-reach li {
    grid-template-columns: 5rem minmax(0, 1fr);
    align-items: baseline;
    gap: 1rem;
  }
}

@media (min-width: 760px) {
  .page-about .about-principle {
    grid-template-columns: 7rem minmax(0, 1fr);
    gap: 1.5rem;
    align-items: start;
  }
}

@media (min-width: 900px) {
  .page-about .about-hero__inner {
    grid-template-columns: minmax(0, 1.12fr) minmax(0, .88fr);
    gap: clamp(2rem, 5vw, 4rem);
  }

  .page-about .about-chapter__grid {
    grid-template-columns: var(--about-track) minmax(0, 1fr);
    gap: clamp(1.5rem, 4vw, 3.5rem);
  }

  .page-about .about-chapter__index {
    position: sticky;
    top: calc(var(--header-h) + 1.5rem);
    align-self: start;
    flex-direction: column;
    align-items: flex-start;
    gap: .5rem;
  }

  .page-about .about-chapter__label {
    padding-left: 2px;
  }

  .page-about .about-figure--wide img {
    aspect-ratio: 2 / 1;
  }
}

@media (min-width: 1040px) {
  .page-about .about-ability {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

@media (hover: hover) {
  .page-about .about-ability__cell:hover {
    background: rgba(79, 209, 197, .07);
  }

  .page-about .about-ability__cell:hover::before {
    width: 52px;
    background: var(--gold);
  }

  .page-about .about-ability__cell:hover .about-ability__text {
    color: var(--ink-brown);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-toc__link,
  .page-about .about-ability__cell,
  .page-about .about-ability__cell::before,
  .page-about .about-ability__text,
  .page-about .about-yearnav__item,
  .page-about .about-node::before,
  .page-about .about-node__year,
  .page-about .about-link {
    transition: none;
  }
}

@supports (animation-timeline: view()) {
  @media (prefers-reduced-motion: no-preference) {
    .page-about .about-num {
      animation: about-num-lift linear both;
      animation-timeline: view();
      animation-range: entry 10% cover 45%;
    }
  }
}

@keyframes about-num-lift {
  from {
    color: rgba(200, 162, 74, .18);
  }
  to {
    color: rgba(200, 162, 74, .55);
  }
}
<<<END>>>