.page-about {
  --about-line: var(--rule);
  --about-card: var(--board);
  overflow-x: clip;
}

/* 面包屑 */
.page-about .about-crumb {
  padding-top: 18px;
}
.page-about .about-crumb__sep {
  margin: 0 0.45em;
  color: var(--steel);
}

/* 档案封面 */
.page-about .about-cover {
  position: relative;
  margin-top: 16px;
  border-top: 1px solid var(--about-line);
  background: linear-gradient(180deg, rgba(10, 108, 124, 0.16) 0%, rgba(5, 7, 12, 0) 62%);
}
.page-about .about-cover::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image: repeating-linear-gradient(90deg, rgba(35, 42, 54, 0.42) 0 1px, transparent 1px 84px);
  pointer-events: none;
}
.page-about .about-cover__inner {
  position: relative;
  display: grid;
  gap: 28px;
  padding: 34px 0 40px;
}
.page-about .about-cover__text {
  position: relative;
  min-width: 0;
}
.page-about .about-cover__no {
  position: absolute;
  top: -0.28em;
  right: -0.04em;
  z-index: 0;
  font-size: clamp(4.6rem, 22vw, 10rem);
  line-height: 1;
  letter-spacing: -0.04em;
  color: transparent;
  -webkit-text-stroke: 1px var(--about-line);
  pointer-events: none;
  user-select: none;
}
.page-about .about-cover__text > *:not(.about-cover__no) {
  position: relative;
  z-index: 1;
}
.page-about .about-cover__text h1 {
  margin: 10px 0 14px;
  font-size: clamp(1.7rem, 6.4vw, 3.05rem);
  line-height: 1.14;
  font-weight: 800;
  letter-spacing: -0.015em;
  color: var(--paper);
}
.page-about .about-cover__text .lede {
  max-width: 46ch;
  margin: 0 0 20px;
  color: var(--steel);
  line-height: 1.75;
}
.page-about .about-cover__figure {
  border: 1px solid var(--about-line);
  background: var(--hold);
  box-shadow: var(--shadow-stack);
}
.page-about .about-cover__figure .media-frame__img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
}
.page-about .about-ruler {
  position: relative;
  height: 16px;
  border-top: 1px solid var(--about-line);
  background-image: repeating-linear-gradient(90deg, var(--about-line) 0 1px, transparent 1px 26px);
  background-repeat: repeat-x;
  background-size: auto 9px;
}

/* 两栏骨架 */
.page-about .about-layout {
  display: grid;
  gap: 30px;
  padding: 36px 0 72px;
}
.page-about .about-rail {
  min-width: 0;
}
.page-about .about-rail .toc__list {
  display: flex;
  gap: 8px;
  margin: 0;
  padding: 0 0 6px;
  list-style: none;
  overflow-x: auto;
}
.page-about .about-rail .toc__item {
  flex: 0 0 auto;
}
.page-about .about-rail .toc__link {
  display: block;
  padding: 7px 11px;
  border: 1px solid var(--about-line);
  background: var(--about-card);
  color: var(--steel);
  font-size: 0.82rem;
  white-space: nowrap;
  text-decoration: none;
}
.page-about .about-rail .toc__link:hover,
.page-about .about-rail .toc__link:focus-visible {
  color: var(--cyan);
  border-color: var(--cyan);
}
.page-about .about-rail .toc__link[aria-current="true"] {
  color: var(--ink);
  background: var(--cyan);
  border-color: var(--cyan);
}
.page-about .about-flow {
  display: flex;
  flex-direction: column;
  gap: 54px;
  min-width: 0;
}

/* 章节头 */
.page-about .about-sec {
  padding: 0;
}
.page-about .about-sec__head {
  display: flex;
  align-items: baseline;
  gap: 12px;
  border-bottom: 1px solid var(--about-line);
  padding-bottom: 12px;
  margin-bottom: 16px;
}
.page-about .about-sec__no {
  margin: 0;
  font-size: 0.86rem;
  letter-spacing: 0.14em;
  color: var(--cyan);
}
.page-about .about-sec__head h2 {
  margin: 0;
  font-size: clamp(1.24rem, 4.4vw, 1.72rem);
  line-height: 1.28;
  font-weight: 800;
  color: var(--paper);
}
.page-about .about-sec__lede {
  max-width: 62ch;
  margin: 0 0 22px;
  color: var(--steel);
  line-height: 1.8;
}

/* 维护角色 */
.page-about .about-roles {
  display: grid;
  gap: 1px;
  margin-bottom: 26px;
  border: 1px solid var(--about-line);
  background: var(--about-line);
}
.page-about .about-role {
  border: 0;
  border-radius: 0;
  padding: 18px 16px;
  background: var(--about-card);
}
.page-about .about-role__no {
  margin: 0 0 8px;
  font-size: 0.74rem;
  letter-spacing: 0.2em;
  color: var(--steel);
}
.page-about .about-role .card__title {
  margin: 0 0 8px;
  font-size: 1.02rem;
  color: var(--paper);
}
.page-about .about-role .card__meta {
  margin: 0;
  color: var(--steel);
  line-height: 1.72;
  font-size: 0.92rem;
}
.page-about .about-role.card--amber {
  border-left: 3px solid var(--amber);
  background: linear-gradient(90deg, rgba(255, 164, 28, 0.09) 0%, rgba(18, 22, 31, 1) 46%);
}

/* 图表 */
.page-about .about-figure {
  margin: 0 0 24px;
  border: 1px solid var(--about-line);
  background: var(--hold);
}
.page-about .about-figure .media-frame__img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
}
.page-about .about-figure .media-frame__caption {
  padding: 10px 14px;
  border-top: 1px solid var(--about-line);
  color: var(--steel);
  font-size: 0.82rem;
  line-height: 1.6;
}

/* 数据清单 */
.page-about .about-facts {
  border-top: 1px solid var(--about-line);
}
.page-about .about-facts .data-list__row {
  display: flex;
  justify-content: space-between;
  gap: 14px;
  padding: 11px 2px;
  border-bottom: 1px solid var(--about-line);
}
.page-about .about-facts .data-list__key {
  color: var(--steel);
  font-size: 0.9rem;
}
.page-about .about-facts .data-list__value {
  color: var(--paper);
  font-size: 0.9rem;
  text-align: right;
}

/* 横向主题带：三条动线 */
.page-about .about-band {
  position: relative;
  padding: 26px 18px 28px;
  border-top: 1px solid var(--about-line);
  border-bottom: 1px solid var(--about-line);
  background: linear-gradient(180deg, rgba(11, 16, 24, 1) 0%, rgba(10, 108, 124, 0.14) 120%);
}
.page-about .about-band .about-sec__head {
  border-bottom-color: rgba(34, 225, 255, 0.28);
}
.page-about .about-band .about-sec__head h2 {
  color: var(--paper);
}
.page-about .about-band .about-sec__lede {
  color: var(--steel);
}
.page-about .about-track {
  display: grid;
  gap: 12px;
  margin: 0 0 18px;
  padding: 0;
  list-style: none;
  counter-reset: track;
}
.page-about .about-track__step {
  position: relative;
  padding: 16px 15px 18px;
  border: 1px solid var(--about-line);
  background: var(--board);
}
.page-about .about-track__step::before {
  content: "";
  position: absolute;
  top: -1px;
  left: -1px;
  width: 42%;
  height: 2px;
  background: var(--grad-edge);
}
.page-about .about-track__no {
  margin: 0 0 8px;
  font-size: 0.76rem;
  letter-spacing: 0.18em;
  color: var(--cyan);
}
.page-about .about-track__step h3 {
  margin: 0 0 8px;
  font-size: 1.06rem;
  font-weight: 800;
  color: var(--paper);
}
.page-about .about-track__step p {
  margin: 0;
  color: var(--steel);
  font-size: 0.91rem;
  line-height: 1.72;
}
.page-about .about-band__note {
  max-width: 60ch;
  margin: 0;
  padding-left: 14px;
  border-left: 2px solid var(--amber);
  color: var(--steel);
  font-size: 0.9rem;
  line-height: 1.75;
}

/* 版本分代 */
.page-about .about-versions {
  margin-bottom: 26px;
}
.page-about .about-versions .filter-bar {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 18px;
}
.page-about .about-versions .filter-btn {
  padding: 7px 14px;
  border: 1px solid var(--about-line);
  background: transparent;
  color: var(--steel);
  font-family: var(--font-sans);
  font-size: 0.85rem;
  letter-spacing: 0.02em;
  cursor: pointer;
}
.page-about .about-versions .filter-btn.is-active {
  color: var(--ink);
  background: var(--cyan);
  border-color: var(--cyan);
}
.page-about .about-versions__grid {
  display: grid;
  gap: 16px;
}
.page-about .about-ver {
  position: relative;
  padding: 18px 16px 18px 20px;
  border-left: 3px solid var(--about-line);
  background: var(--about-card);
}
.page-about .about-ver--main { border-left-color: var(--cyan); }
.page-about .about-ver--maint { border-left-color: var(--amber); }
.page-about .about-ver--archive { border-left-color: var(--steel); }
.page-about .about-ver__code {
  margin: 0 0 6px;
  font-size: 1.5rem;
  line-height: 1;
  color: var(--paper);
  letter-spacing: -0.02em;
}
.page-about .about-ver .card__title {
  margin: 0 0 10px;
  font-size: 1.06rem;
  color: var(--paper);
}
.page-about .about-ver .card__meta {
  margin: 10px 0 0;
  color: var(--steel);
  font-size: 0.9rem;
  line-height: 1.72;
}
.page-about .about-ver__check {
  margin: 12px 0 0;
  padding-top: 10px;
  border-top: 1px dashed var(--about-line);
  color: var(--steel);
  font-size: 0.86rem;
  line-height: 1.68;
}
.page-about .about-versions__empty {
  margin: 0;
  color: var(--steel);
  font-size: 0.9rem;
}
.page-about .about-figure--wide {
  margin-bottom: 0;
}

/* 更正记录 */
.page-about .about-log {
  margin: 0 0 22px;
  padding: 0;
  list-style: none;
  border-top: 1px solid var(--about-line);
}
.page-about .about-log__item {
  display: grid;
  gap: 8px;
  padding: 16px 0;
  border-bottom: 1px solid var(--about-line);
}
.page-about .about-log__code {
  margin: 0;
  font-size: 0.76rem;
  letter-spacing: 0.12em;
  color: var(--cyan);
}
.page-about .about-log__item h3 {
  margin: 0 0 6px;
  font-size: 1rem;
  font-weight: 700;
  color: var(--paper);
}
.page-about .about-log__item p {
  margin: 0;
  color: var(--steel);
  font-size: 0.9rem;
  line-height: 1.72;
}
.page-about .about-notice {
  margin: 0;
}

/* 下一页引导 */
.page-about .about-next {
  padding: 22px 18px 24px;
  border: 1px solid var(--about-line);
  background: linear-gradient(135deg, rgba(34, 225, 255, 0.09) 0%, rgba(18, 22, 31, 1) 58%);
}
.page-about .about-next h2 {
  margin: 0 0 8px;
  font-size: 1.2rem;
  font-weight: 800;
  color: var(--paper);
}
.page-about .about-next__lede {
  margin: 0 0 18px;
  color: var(--steel);
  font-size: 0.92rem;
  line-height: 1.7;
}
.page-about .about-next__links {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

/* 平板与桌面 */
@media (min-width: 720px) {
  .page-about .about-roles {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
  .page-about .about-versions__grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
  .page-about .about-cover__inner {
    grid-template-columns: minmax(0, 1.15fr) minmax(0, 0.85fr);
    align-items: center;
    gap: 36px;
    padding: 46px 0 52px;
  }
  .page-about .about-band {
    padding: 32px 26px 34px;
  }
  .page-about .about-track {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 0;
  }
  .page-about .about-track__step + .about-track__step {
    border-left: 0;
  }
  .page-about .about-log__item {
    grid-template-columns: 76px minmax(0, 1fr);
    gap: 18px;
    align-items: start;
  }
}

@media (min-width: 1040px) {
  .page-about .about-layout {
    grid-template-columns: 196px minmax(0, 1fr);
    gap: 56px;
    padding-top: 52px;
    padding-bottom: 96px;
  }
  .page-about .about-rail {
    position: sticky;
    top: 104px;
    align-self: start;
  }
  .page-about .about-rail .toc__list {
    display: block;
    overflow: visible;
    padding-bottom: 0;
  }
  .page-about .about-rail .toc__item + .toc__item {
    margin-top: 6px;
  }
  .page-about .about-rail .toc__link {
    width: 100%;
    white-space: normal;
    line-height: 1.5;
  }
  .page-about .about-flow {
    gap: 66px;
  }
  .page-about .about-roles {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
  .page-about .about-versions__grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
  .page-about .about-next {
    display: grid;
    grid-template-columns: minmax(0, 1fr) auto;
    align-items: center;
    gap: 8px 28px;
    padding: 28px 30px;
  }
  .page-about .about-next h2,
  .page-about .about-next__lede {
    grid-column: 1;
  }
  .page-about .about-next__lede {
    margin-bottom: 0;
  }
  .page-about .about-next__links {
    grid-column: 2;
    grid-row: 1 / span 2;
    justify-content: flex-end;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about * {
    transition: none !important;
    animation: none !important;
  }
}
<<<END>>>