.page-about {
  --about-note-w: 300px;
  padding-bottom: clamp(40px, 8vw, 96px);
}

.page-about .about-hero {
  position: relative;
  display: grid;
  gap: clamp(20px, 3vw, 40px);
  padding-block: clamp(18px, 3.6vw, 40px) clamp(26px, 4.6vw, 52px);
  overflow: hidden;
}

.page-about .about-hero__ghost {
  position: absolute;
  top: -6%;
  right: -3%;
  z-index: 0;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(3.4rem, 15vw, 11rem);
  letter-spacing: -0.04em;
  line-height: 1;
  white-space: nowrap;
  color: transparent;
  -webkit-text-stroke: 1px var(--line);
  pointer-events: none;
  user-select: none;
}

.page-about .about-hero__text {
  position: relative;
  z-index: 1;
}

.page-about .about-hero__title {
  margin: 0.18em 0 0.34em;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(2.3rem, 8.4vw, 5rem);
  line-height: 0.96;
  letter-spacing: -0.02em;
  color: var(--paper);
}

.page-about .about-hero__lead {
  max-width: 54ch;
  margin: 0;
  font-size: clamp(15px, 1.06vw, 17px);
  line-height: 1.86;
  color: var(--paper);
}

.page-about .about-hero__facts {
  display: flex;
  flex-wrap: wrap;
  gap: clamp(14px, 2.4vw, 32px);
  margin: clamp(18px, 2.6vw, 28px) 0 0;
  padding: clamp(14px, 2vw, 18px) 0 0;
  border-top: 1px solid var(--line);
  list-style: none;
}

.page-about .about-hero__facts li {
  display: flex;
  flex-direction: column;
  gap: 3px;
}

.page-about .about-hero__facts .k {
  font-family: var(--font-mono);
  font-size: clamp(1.15rem, 2.4vw, 1.6rem);
  font-weight: 800;
  line-height: 1;
  font-variant-numeric: tabular-nums;
  color: var(--cyan);
}

.page-about .about-hero__facts .k--gold {
  color: var(--gold);
}

.page-about .about-hero__facts .l {
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--muted);
}

.page-about .about-figure {
  margin: 0;
}

.page-about .about-figure img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  border: 1px solid var(--line);
  object-fit: cover;
}

.page-about .about-figure--hero img {
  aspect-ratio: 4 / 3;
}

.page-about .about-figure__cap {
  margin-top: 10px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.07em;
  color: var(--muted);
}

.page-about .about-body {
  display: grid;
  gap: clamp(24px, 4vw, 52px);
  padding-block: clamp(10px, 2.4vw, 22px);
}

/* 章节索引 */
.page-about .about-toc {
  border-top: 2px solid var(--red);
  padding-top: 14px;
}

.page-about .about-toc__title {
  margin: 0 0 12px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--muted);
}

.page-about .about-toc__list {
  display: flex;
  flex-wrap: wrap;
  gap: 4px 16px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .about-toc__link {
  display: flex;
  align-items: baseline;
  gap: 8px;
  padding: 4px 0;
  font-size: 13.5px;
  line-height: 1.5;
  color: var(--muted);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color 0.18s var(--ease), border-color 0.18s var(--ease);
}

.page-about .about-toc__link .i {
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 700;
  color: var(--gold);
  font-variant-numeric: tabular-nums;
}

.page-about .about-toc__link:hover,
.page-about .about-toc__link:focus-visible {
  color: var(--paper);
  border-bottom-color: var(--red);
}

.page-about .about-toc__link[aria-current] {
  color: var(--paper);
  border-bottom-color: var(--cyan);
}

/* 时间线主列 */
.page-about .about-flow {
  position: relative;
  min-width: 0;
}

.page-about .about-flow::before {
  content: "";
  position: absolute;
  left: 4px;
  top: 10px;
  bottom: 10px;
  width: 1px;
  background: var(--line);
}

.page-about .about-sec {
  position: relative;
  padding-left: clamp(20px, 3.4vw, 40px);
  padding-block: clamp(24px, 3.6vw, 46px);
}

.page-about .about-sec::before {
  content: "";
  position: absolute;
  left: 0;
  top: clamp(32px, 4vw, 56px);
  width: 9px;
  height: 9px;
  background: var(--gold);
  transform: rotate(45deg);
  box-shadow: 0 0 0 4px var(--ink);
}

.page-about .about-sec:first-child {
  padding-top: 0;
}

.page-about .about-sec:first-child::before {
  top: 6px;
}

.page-about .about-sec__head {
  display: flex;
  align-items: flex-start;
  gap: clamp(10px, 1.8vw, 18px);
  margin-bottom: clamp(14px, 2vw, 22px);
}

.page-about .about-sec__num {
  flex: none;
  font-family: var(--font-mono);
  font-size: clamp(1.8rem, 5vw, 3rem);
  font-weight: 800;
  line-height: 0.9;
  letter-spacing: -0.03em;
  color: transparent;
  -webkit-text-stroke: 1px var(--elevated);
}

.page-about .about-sec__meta .eyebrow {
  margin: 0;
}

.page-about .about-sec__title {
  margin: 6px 0 0;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(1.5rem, 4vw, 2.4rem);
  line-height: 1.12;
  letter-spacing: -0.01em;
  color: var(--paper);
}

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

.page-about .about-prose p {
  max-width: 62ch;
  margin: 0 0 1em;
  font-size: clamp(15px, 1.04vw, 17px);
  line-height: 1.88;
  color: var(--paper);
}

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

.page-about .about-prose strong {
  font-weight: 700;
  color: var(--cyan);
  font-variant-numeric: tabular-nums;
}

/* 暖纸旁注 */
.page-about .about-note {
  align-self: start;
  padding: clamp(15px, 1.8vw, 22px);
  background: var(--paper-bright);
  color: var(--ink);
  border-left: 3px solid var(--red);
}

.page-about .about-note__tag {
  display: inline-block;
  margin-bottom: 10px;
  font-family: var(--font-mono);
  font-size: 10.5px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--red);
}

.page-about .about-note p {
  max-width: none;
  margin: 0 0 0.8em;
  font-size: 14px;
  line-height: 1.78;
  color: var(--ink);
}

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

.page-about .about-note strong {
  color: var(--ink);
  font-weight: 700;
  font-variant-numeric: tabular-nums;
}

.page-about .about-note__figure {
  margin: 0 0 12px;
}

.page-about .about-note__figure img {
  display: block;
  width: 100%;
  height: auto;
  border: 1px solid #D8D0BE;
  object-fit: cover;
}

.page-about .about-sec__figure {
  margin-top: clamp(16px, 2.2vw, 26px);
}

/* 版本阶梯 */
.page-about .about-ladder {
  margin-top: clamp(18px, 2.6vw, 28px);
  padding: clamp(14px, 2vw, 22px);
  border: 1px solid var(--line);
  background: var(--panel);
}

.page-about .about-ladder svg {
  display: block;
  width: 100%;
  height: auto;
}

.page-about .about-ladder__cap {
  margin: 10px 0 0;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.07em;
  color: var(--muted);
}

/* 数字条 */
.page-about .about-figures {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: clamp(16px, 2.2vw, 24px) 0 0;
  padding: 0;
  list-style: none;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .about-figures li {
  display: flex;
  flex-direction: column;
  gap: 5px;
  padding: 14px 14px 16px;
  background: var(--panel);
}

.page-about .about-figures .n {
  font-family: var(--font-mono);
  font-size: clamp(1.3rem, 3vw, 1.9rem);
  font-weight: 800;
  line-height: 1;
  font-variant-numeric: tabular-nums;
  color: var(--cyan);
}

.page-about .about-figures li:nth-child(2n) .n {
  color: var(--gold);
}

.page-about .about-figures .l {
  font-size: 12px;
  color: var(--muted);
}

/* 版本里程碑 */
.page-about .about-miles {
  display: grid;
  gap: 10px;
  margin-top: clamp(16px, 2.4vw, 26px);
}

.page-about .about-miles__item {
  border: 1px solid var(--line);
  background: var(--panel);
}

.page-about .about-miles__item summary {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 10px;
  padding: 14px 16px;
  cursor: pointer;
  list-style: none;
}

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

.page-about .about-miles__item summary::after {
  content: "+";
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: 16px;
  line-height: 1;
  color: var(--cyan);
}

.page-about .about-miles__item[open] summary::after {
  content: "\2212";
}

.page-about .about-miles__item summary:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: -2px;
}

.page-about .about-miles__ver {
  font-family: var(--font-mono);
  font-size: 14px;
  font-weight: 800;
  letter-spacing: 0.04em;
  color: var(--paper);
}

.page-about .about-miles__kind {
  padding: 2px 8px;
  border: 1px solid var(--line);
  font-size: 11px;
  letter-spacing: 0.12em;
  color: var(--gold);
}

.page-about .about-miles__label {
  font-size: 13.5px;
  color: var(--muted);
}

.page-about .about-miles__body {
  padding: 0 16px 16px;
}

.page-about .about-miles__body p {
  max-width: 62ch;
  margin: 0;
  font-size: 14px;
  line-height: 1.8;
  color: var(--muted);
}

/* 收束入口 */
.page-about .about-cta {
  display: grid;
  gap: clamp(14px, 2vw, 24px);
  margin-top: clamp(26px, 4vw, 44px);
  padding-top: clamp(18px, 2.6vw, 28px);
  border-top: 2px solid var(--red);
}

.page-about .about-cta h2 {
  margin: 0 0 8px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(1.4rem, 3.2vw, 2rem);
  line-height: 1.14;
  letter-spacing: -0.01em;
  color: var(--paper);
}

.page-about .about-cta p {
  max-width: 52ch;
  margin: 0;
  font-size: 14.5px;
  line-height: 1.82;
  color: var(--muted);
}

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

@media (min-width: 640px) {
  .page-about .about-figures {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .about-figures li:nth-child(3) .n {
    color: var(--cyan);
  }

  .page-about .about-figures li:nth-child(4) .n {
    color: var(--gold);
  }
}

@media (min-width: 820px) {
  .page-about .about-hero {
    grid-template-columns: minmax(0, 1.06fr) minmax(0, 0.94fr);
    align-items: center;
  }

  .page-about .about-figure--hero img {
    aspect-ratio: 16 / 10;
  }

  .page-about .about-cta {
    grid-template-columns: minmax(0, 1fr) auto;
    align-items: end;
  }
}

@media (min-width: 1000px) {
  .page-about .about-body {
    grid-template-columns: 216px minmax(0, 1fr);
    align-items: start;
  }

  .page-about .about-toc {
    position: sticky;
    top: calc(var(--tick-h) + 20px);
  }

  .page-about .about-toc__list {
    display: block;
  }

  .page-about .about-toc__link {
    padding: 9px 0;
    border-bottom: 1px solid var(--line);
  }

  .page-about .about-toc__link:hover,
  .page-about .about-toc__link:focus-visible {
    padding-left: 6px;
  }
}

@media (min-width: 1180px) {
  .page-about .about-sec__body {
    grid-template-columns: minmax(0, 1fr) var(--about-note-w);
    align-items: start;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-toc__link {
    transition: none;
  }
}
<<<PAGE_CSS_END>>>