.page-about {
  --rail-w: 236px;
  --sticky-top: 96px;
  background: var(--cream);
  color: var(--brown-ink);
}

/* ---------- 面包屑 ---------- */
.page-about .about-crumb {
  padding-top: clamp(14px, 2.2vw, 24px);
}
.page-about .about-crumb .breadcrumbs {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--stone-grey);
}
.page-about .about-crumb .breadcrumbs a {
  color: var(--stone-grey);
  text-decoration: none;
}
.page-about .about-crumb .breadcrumbs a:hover {
  color: var(--rock-red);
}

/* ---------- 顶部横幅 ---------- */
.page-about .about-banner {
  position: relative;
  isolation: isolate;
  overflow: hidden;
  background: var(--ink-green);
  border-bottom: 1px solid var(--hairline-gold);
  margin-top: clamp(12px, 2vw, 20px);
}
.page-about .about-banner__img {
  position: absolute;
  inset: 0;
  z-index: 0;
  width: 100%;
  height: 100%;
  max-width: none;
  object-fit: cover;
  object-position: center 40%;
  opacity: 0.18;
  filter: saturate(0.55) contrast(1.06);
  pointer-events: none;
}
.page-about .about-banner__inner {
  position: relative;
  z-index: 1;
  max-width: 780px;
  padding: clamp(34px, 6vw, 62px) 0 clamp(30px, 4.6vw, 50px);
}
.page-about .about-banner h1 {
  margin: 14px 0 18px;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(27px, 5.2vw, 46px);
  line-height: 1.16;
  letter-spacing: -0.02em;
  color: var(--on-dark-strong);
}
.page-about .about-banner__lede {
  margin: 0;
  max-width: 60ch;
  font-size: clamp(15px, 1.55vw, 17px);
  line-height: 1.85;
  color: var(--on-dark);
}

/* ---------- 主体骨架 ---------- */
.page-about .about-grid {
  padding-block: clamp(30px, 5vw, 66px);
}
@media (min-width: 960px) {
  .page-about .about-grid {
    display: grid;
    grid-template-columns: var(--rail-w) minmax(0, 1fr);
    column-gap: clamp(34px, 4.6vw, 76px);
    align-items: start;
  }
}

/* ---------- 左侧版本索引 ---------- */
.page-about .about-rail {
  margin-bottom: clamp(26px, 4vw, 0px);
}
@media (min-width: 960px) {
  .page-about .about-rail {
    position: sticky;
    top: var(--sticky-top);
    margin-bottom: 0;
  }
}
.page-about .about-versions {
  list-style: none;
  margin: 12px 0 0;
  padding: 0 0 0 0;
  border-left: 1px solid var(--stone-line);
}
.page-about .about-versions__link {
  position: relative;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 3px;
  padding: 11px 0 11px 20px;
  color: inherit;
  text-decoration: none;
  transition: color 120ms linear, background 120ms linear;
}
.page-about .about-versions__link::before {
  content: "";
  position: absolute;
  left: -4.5px;
  top: 17px;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--sand-gold);
  transition: background 120ms linear, transform 120ms linear;
}
.page-about .about-versions__link:hover,
.page-about .about-versions__link:focus-visible {
  background: var(--cyan-wash);
  outline: none;
}
.page-about .about-versions__link:hover::before,
.page-about .about-versions__link:focus-visible::before {
  background: var(--data-cyan);
  transform: scale(1.25);
}
.page-about .about-versions__num {
  font-family: var(--font-mono);
  font-size: 12.5px;
  font-weight: 700;
  letter-spacing: 0.08em;
  color: var(--sand-gold);
}
.page-about .about-versions__note {
  font-size: 12.5px;
  line-height: 1.6;
  color: var(--stone-grey);
}
.page-about .about-rail__note {
  margin: 18px 0 0;
  padding-left: 20px;
  font-size: 12.5px;
  line-height: 1.75;
  color: var(--stone-grey);
  border-left: 1px solid var(--stone-line);
}

/* ---------- 正文分区 ---------- */
.page-about .about-column {
  min-width: 0;
}
.page-about .about-section {
  padding-block: clamp(4px, 1vw, 10px) clamp(26px, 4vw, 46px);
}
.page-about .about-section + .about-section {
  border-top: 1px solid var(--stone-line);
  padding-top: clamp(26px, 4vw, 46px);
}
.page-about .about-section h2 {
  margin: 10px 0 16px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(21px, 2.9vw, 31px);
  line-height: 1.28;
  letter-spacing: -0.02em;
  color: var(--brown-ink);
}
.page-about .about-section h3 {
  margin: 0 0 8px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(16px, 1.8vw, 19px);
  line-height: 1.4;
  letter-spacing: -0.01em;
  color: var(--brown-ink);
}
.page-about .about-section p {
  margin: 0 0 14px;
  font-size: var(--step-1);
  line-height: 1.85;
  color: var(--brown-ink);
}
.page-about .about-section p:last-child {
  margin-bottom: 0;
}
.page-about .about-section__lede {
  max-width: 62ch;
  color: var(--stone-grey);
}

/* ---------- 斜向切分 ---------- */
.page-about .about-slant {
  height: 2px;
  background: var(--sand-gold);
  opacity: 0.55;
  transform: rotate(-1.2deg);
  transform-origin: 0 50%;
  margin: clamp(22px, 3.4vw, 40px) 0;
  transition: transform 240ms linear;
}

/* ---------- 口径四原则：折叠行 ---------- */
.page-about .about-principles {
  margin-top: 20px;
  border-top: 1px solid var(--stone-line);
}
.page-about .about-principles .accordion__item {
  border-bottom: 1px solid var(--stone-line);
}
.page-about .about-principles__head {
  margin: 0;
}
.page-about .about-principles__trigger {
  position: relative;
  display: grid;
  grid-template-columns: 3.2rem minmax(0, 1fr);
  gap: 4px 14px;
  width: 100%;
  padding: 15px 2.2rem 15px 0;
  border: 0;
  background: none;
  font: inherit;
  color: inherit;
  text-align: left;
  cursor: pointer;
  transition: background 120ms linear;
}
.page-about .about-principles__trigger:hover,
.page-about .about-principles__trigger:focus-visible {
  background: var(--cyan-wash);
  outline: none;
  box-shadow: inset 2px 0 0 var(--data-cyan);
}
.page-about .about-principles__num {
  font-family: var(--font-mono);
  font-size: 12.5px;
  font-weight: 700;
  letter-spacing: 0.08em;
  color: var(--sand-gold);
  padding-top: 3px;
}
.page-about .about-principles__name {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: var(--step-2);
  letter-spacing: -0.01em;
}
.page-about .about-principles__hint {
  grid-column: 2 / -1;
  font-size: 13.5px;
  line-height: 1.7;
  color: var(--stone-grey);
}
.page-about .about-principles__chev {
  position: absolute;
  right: 0.4rem;
  top: 21px;
  width: 9px;
  height: 9px;
  border-right: 1.5px solid var(--stone-grey);
  border-bottom: 1.5px solid var(--stone-grey);
  transform: rotate(45deg);
  transition: transform 180ms linear, border-color 120ms linear;
}
.page-about .about-principles__trigger[aria-expanded="true"] .about-principles__chev {
  transform: rotate(-135deg);
  border-color: var(--data-cyan);
}
.page-about .about-principles__trigger[aria-expanded="true"] {
  box-shadow: inset 2px 0 0 var(--data-cyan);
}
@media (min-width: 720px) {
  .page-about .about-principles__trigger {
    grid-template-columns: 3.2rem 8.6rem minmax(0, 1fr);
    align-items: baseline;
  }
  .page-about .about-principles__hint {
    grid-column: 3;
    padding-top: 4px;
  }
}

/* ---------- 字段释义对 ---------- */
.page-about .about-field {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 0;
  margin: 0;
  border-top: 1px solid var(--stone-line);
}
@media (min-width: 640px) {
  .page-about .about-field {
    grid-template-columns: 9.5rem minmax(0, 1fr);
  }
}
.page-about .about-field dt {
  padding: 10px 0 4px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--stone-grey);
}
.page-about .about-field dd {
  margin: 0;
  padding: 0 0 12px;
  font-size: var(--step-0);
  line-height: 1.8;
  color: var(--brown-ink);
}
@media (min-width: 640px) {
  .page-about .about-field dt {
    padding: 12px 14px 12px 0;
    border-right: 1px solid var(--stone-line);
  }
  .page-about .about-field dd {
    padding: 12px 0 12px 16px;
  }
}
.page-about .about-field--open {
  border-top: 0;
}
.page-about .about-field--open dt,
.page-about .about-field--open dd {
  border-bottom: 1px solid var(--stone-line);
}
.page-about .about-field--open dd:last-of-type,
.page-about .about-field--open dt:last-of-type {
  border-bottom: 0;
}

/* ---------- 赛季时间线 ---------- */
.page-about .about-eras {
  list-style: none;
  margin: 20px 0 0;
  padding: 0 0 0 20px;
  border-left: 1px solid var(--stone-line);
}
.page-about .about-eras__item {
  position: relative;
  padding: 6px 0 22px 0;
  scroll-margin-top: 130px;
}
.page-about .about-eras__item:last-child {
  padding-bottom: 4px;
}
.page-about .about-eras__item::before {
  content: "";
  position: absolute;
  left: -24.5px;
  top: 15px;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--sand-gold);
  transition: background 120ms linear, transform 120ms linear;
}
.page-about .about-eras__item:target::before {
  background: var(--data-cyan);
  transform: scale(1.3);
}
.page-about .about-eras__item:target {
  background: linear-gradient(90deg, var(--cyan-wash), rgba(46, 196, 182, 0) 64%);
}
.page-about .about-eras__meta {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 6px 10px;
  margin: 0 0 4px;
}
.page-about .about-eras__season {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--stone-grey);
}
.page-about .about-eras__version {
  font-family: var(--font-mono);
  font-size: 12.5px;
  font-weight: 700;
  letter-spacing: 0.06em;
  color: var(--rock-red);
}
.page-about .about-eras__item h3 {
  margin: 0 0 6px;
}
.page-about .about-eras__item p {
  margin: 0;
  font-size: var(--step-0);
  line-height: 1.82;
  color: var(--brown-ink);
}
@media (min-width: 720px) {
  .page-about .about-eras__item {
    display: grid;
    grid-template-columns: 8.8rem minmax(0, 1fr);
    column-gap: 22px;
    padding-bottom: 24px;
  }
  .page-about .about-eras__meta {
    grid-column: 1;
    grid-row: 1 / span 2;
    flex-direction: column;
    gap: 4px;
  }
  .page-about .about-eras__item h3 {
    grid-column: 2;
    grid-row: 1;
  }
  .page-about .about-eras__item > p:not(.about-eras__meta) {
    grid-column: 2;
    grid-row: 2;
  }
}

/* ---------- 配图 ---------- */
.page-about .about-figure {
  margin: clamp(20px, 3vw, 30px) 0 0;
}
.page-about .about-figure img {
  display: block;
  width: 100%;
  height: auto;
  max-width: 100%;
  object-fit: cover;
  border: 1px solid var(--stone-line);
  box-shadow: var(--shadow-hair);
}
.page-about .about-figure figcaption {
  margin-top: 9px;
  font-size: 13px;
  line-height: 1.72;
  color: var(--stone-grey);
}

/* ---------- 团队构成 ---------- */
.page-about .about-team {
  list-style: none;
  display: grid;
  gap: 1px;
  margin: 20px 0 22px;
  padding: 1px;
  background: var(--stone-line);
  border: 1px solid var(--stone-line);
}
@media (min-width: 640px) {
  .page-about .about-team {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}
.page-about .about-team__item {
  display: grid;
  gap: 3px;
  padding: 16px 16px 18px;
  background: var(--etch-white);
}
.page-about .about-team__num {
  color: var(--sand-gold);
  line-height: 1;
}
.page-about .about-team__role {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: var(--step-0);
  color: var(--brown-ink);
}
.page-about .about-team__desc {
  font-size: 13px;
  line-height: 1.7;
  color: var(--stone-grey);
}

/* ---------- 服务边界面板 ---------- */
.page-about .about-boundary {
  margin: 18px 0 22px;
  padding: clamp(16px, 2.6vw, 26px);
  background: var(--etch-white);
  border: 1px solid var(--stone-line);
  border-left: 3px solid var(--rock-red);
  box-shadow: var(--shadow-hair);
}
.page-about .about-boundary__note {
  margin: 0;
  padding-top: 14px;
  font-size: 13.5px;
  line-height: 1.8;
  color: var(--stone-grey);
  border-top: 1px solid var(--stone-line);
}

/* ---------- 引用块 ---------- */
.page-about .about-cite {
  margin-top: 18px;
  padding: clamp(16px, 2.6vw, 26px);
  background: var(--pale-sand);
  border: 1px solid var(--stone-line);
}
.page-about .about-cite__sample {
  margin: 10px 0 16px;
  padding: 12px 14px;
  background: var(--etch-white);
  border-left: 2px solid var(--data-cyan);
  font-family: var(--font-mono);
  font-size: 13.5px;
  font-weight: 700;
  line-height: 1.8;
  letter-spacing: 0.01em;
  color: var(--brown-ink);
  overflow-wrap: anywhere;
}
.page-about .about-cite__list {
  margin: 0 0 14px;
  padding-left: 1.1em;
  list-style: square;
}
.page-about .about-cite__list li {
  margin-bottom: 6px;
  font-size: var(--step-0);
  line-height: 1.78;
  color: var(--brown-ink);
}
.page-about .about-cite__note {
  margin: 0;
  padding-top: 12px;
  font-size: 13px;
  line-height: 1.78;
  color: var(--stone-grey);
  border-top: 1px solid var(--stone-line);
}

/* ---------- 继续查阅 ---------- */
.page-about .about-section--next {
  border-top: 1px solid var(--stone-line);
}
.page-about .about-links {
  list-style: none;
  margin: 14px 0 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--stone-line);
  border: 1px solid var(--stone-line);
}
@media (min-width: 760px) {
  .page-about .about-links {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}
.page-about .about-links li {
  background: var(--cream);
}
.page-about .about-links__a {
  display: block;
  padding: 14px 16px;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.03em;
  color: var(--brown-ink);
  text-decoration: none;
  transition: background 120ms linear, color 120ms linear;
}
.page-about .about-links__a:hover,
.page-about .about-links__a:focus-visible {
  background: var(--cyan-wash);
  color: var(--ink-green);
  box-shadow: inset 2px 0 0 var(--data-cyan);
  outline: none;
}

/* ---------- 降低动效 ---------- */
@media (prefers-reduced-motion: reduce) {
  .page-about .about-slant {
    transform: none;
    transition: none;
  }
  .page-about .about-versions__link,
  .page-about .about-versions__link::before,
  .page-about .about-principles__chev,
  .page-about .about-eras__item::before,
  .page-about .about-links__a {
    transition: none;
  }
}
<<<END>>>