.page-about {
  --about-rail: 206px;
  --about-figure-line: rgba(11, 22, 34, .12);
  background: var(--paper-100);
  color: var(--ink-980);
  overflow-x: hidden;
}

/* ---------- 档案封页 ---------- */

.page-about .about-hero {
  position: relative;
  background: var(--ink-980);
  color: var(--paper-100);
  padding: clamp(22px, 3vw, 40px) 0 clamp(40px, 5.5vw, 80px);
  overflow: hidden;
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(var(--line-soft) 1px, transparent 1px),
    linear-gradient(90deg, var(--line-soft) 1px, transparent 1px);
  background-size: 72px 72px;
  pointer-events: none opacity: 1;
  opacity: .55;
  -webkit-mask-image: radial-gradient(130% 92% at 18% 0%, #000 18%, transparent 76%);
  mask-image: radial-gradient(130% 92% at 18% 0%, #000 18%, transparent 76%);
}

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

.page-about .about-hero .breadcrumb {
  font-size: .8125rem;
  color: var(--silver-400);
}

.page-about .about-hero .breadcrumb a {
  color: var(--silver-400);
  text-decoration: none;
}

.page-about .about-hero .breadcrumb a:hover {
  color: var(--cyan);
}

.page-about .about-hero__grid {
  margin-top: clamp(22px, 3.4vw, 44px);
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(24px, 3.2vw, 44px);
  align-items: end;
}

.page-about .about-kicker {
  display: flex;
  align-items: center;
  gap: 12px;
  margin: 0;
}

.page-about .about-kicker__no {
  font-size: .75rem;
  letter-spacing: .18em;
  color: var(--silver-400);
}

.page-about .about-hero__title {
  margin: 16px 0 0;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(2rem, 5.6vw, 4.25rem);
  line-height: 1.08;
  letter-spacing: -.02em;
  color: var(--paper-100);
  max-width: 17ch;
}

.page-about .about-hero__lede {
  margin: clamp(16px, 2vw, 22px) 0 0;
  max-width: 44ch;
  font-size: clamp(.9375rem, 1.05vw, 1.0625rem);
  line-height: 1.85;
  color: rgba(244, 238, 227, .76);
}

.page-about .about-hero__facts {
  list-style: none;
  margin: clamp(24px, 3.4vw, 38px) 0 0;
  padding: 1px;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--line-dark);
  border: 1px solid var(--line-dark);
}

.page-about .about-hero__facts li {
  background: var(--ink-980);
  padding: clamp(12px, 1.7vw, 18px);
  display: flex;
  flex-direction: column;
  gap: 6px;
  min-width: 0;
}

.page-about .about-hero__num {
  font-size: clamp(1.5rem, 3vw, 2.25rem);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -.02em;
  color: var(--paper-100);
}

.page-about .about-hero__unit {
  font-size: .8125rem;
  color: var(--silver-400);
  letter-spacing: .02em;
}

.page-about .about-hero__figure {
  margin: 0;
  border: 1px solid var(--line-dark);
  background: var(--ink-800);
  padding: 8px;
}

.page-about .about-hero__figure img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 16 / 9;
  object-fit: cover;
  filter: saturate(.72) contrast(1.06);
}

.page-about .about-hero__figure figcaption {
  margin-top: 10px;
  padding: 0 2px;
  font-size: .75rem;
  line-height: 1.6;
  color: var(--silver-400);
}

/* ---------- 主页体：窄索引 + 宽内容 ---------- */

.page-about .about-body {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: clamp(28px, 4vw, 60px) var(--edge) clamp(48px, 7vw, 104px);
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(26px, 3.4vw, 52px);
  align-items: start;
}

.page-about .about-rail {
  border-bottom: 1px solid var(--line-light);
  padding-bottom: 14px;
}

.page-about .about-rail__title {
  margin: 0;
  font-size: .6875rem;
  letter-spacing: .22em;
  color: var(--silver-600);
}

.page-about .about-rail__list {
  list-style: none;
  margin: 10px 0 0;
  padding: 0 0 4px;
  display: flex;
  gap: 8px;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
}

.page-about .about-rail__link {
  display: inline-block;
  white-space: nowrap;
  font-size: .875rem;
  text-decoration: none;
  color: var(--silver-600);
  padding: 6px 12px;
  border: 1px solid var(--line-light);
  transition: color .18s ease, border-color .18s ease, background-color .18s ease;
}

.page-about .about-rail__link:hover,
.page-about .about-rail__link[aria-current="true"] {
  color: var(--ink-980);
  border-color: var(--orange);
  background: var(--paper-200);
}

/* ---------- 章节通用 ---------- */

.page-about .about-section + .about-section {
  margin-top: clamp(44px, 6vw, 92px);
}

.page-about .about-section__head {
  display: flex;
  gap: clamp(12px, 1.8vw, 22px);
  align-items: flex-start;
  padding-bottom: 14px;
  border-bottom: 1px solid var(--line-light);
  margin-bottom: clamp(20px, 2.6vw, 32px);
}

.page-about .about-section__no {
  flex: none;
  margin: 0;
  padding-top: .16em;
  font-size: clamp(1.125rem, 2vw, 1.5rem);
  font-weight: 700;
  line-height: 1;
  color: var(--orange);
  letter-spacing: .02em;
}

.page-about .about-section h2 {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(1.5rem, 3.4vw, 2.5rem);
  line-height: 1.2;
  letter-spacing: -.01em;
  color: var(--ink-980);
}

.page-about .about-section__sub {
  margin: 8px 0 0;
  font-size: .875rem;
  line-height: 1.6;
  color: var(--silver-600);
}

.page-about .about-prose {
  max-width: 62ch;
}

.page-about .about-prose p,
.page-about .spec-text p {
  margin: 0 0 1.15em;
  line-height: 1.78;
  color: var(--ink-800);
}

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

.page-about .about-prose a,
.page-about .spec-text a,
.page-about .spec-foot a,
.page-about .timeline__more a,
.page-about .record-boundary a {
  color: var(--ink-980);
  text-decoration: none;
  border-bottom: 1px solid var(--orange);
  padding-bottom: 1px;
}

.page-about .about-prose a:hover,
.page-about .spec-text a:hover,
.page-about .spec-foot a:hover,
.page-about .timeline__more a:hover,
.page-about .record-boundary a:hover {
  color: var(--orange);
}

.page-about .about-note {
  margin-top: clamp(18px, 2.4vw, 28px);
  max-width: 62ch;
  background: var(--paper-200);
  border-left: 3px solid var(--orange);
  padding: clamp(14px, 1.8vw, 20px) clamp(16px, 2vw, 24px);
}

.page-about .about-note__k {
  margin: 0 0 8px;
  font-size: .6875rem;
  letter-spacing: .2em;
  color: var(--silver-600);
}

.page-about .about-note__v {
  margin: 0;
  font-size: .9375rem;
  line-height: 1.78;
  color: var(--ink-980);
}

/* ---------- 时间轴 ---------- */

.page-about .timeline {
  list-style: none;
  margin: 0;
  padding: 0;
  position: relative;
}

.page-about .timeline::before {
  content: "";
  position: absolute;
  left: 6px;
  top: 8px;
  bottom: 8px;
  width: 1px;
  background: linear-gradient(180deg, var(--orange), rgba(228, 102, 31, .1));
}

.page-about .timeline__item {
  position: relative;
  padding: 0 0 clamp(24px, 3.2vw, 38px) clamp(28px, 3.2vw, 44px);
}

.page-about .timeline__item:last-child {
  padding-bottom: 0;
}

.page-about .timeline__item::before {
  content: "";
  position: absolute;
  left: 1px;
  top: 6px;
  width: 11px;
  height: 11px;
  border-radius: 50%;
  background: var(--paper-100);
  border: 2px solid var(--orange);
  transition: background-color .18s ease;
}

.page-about .timeline__item:hover::before {
  background: var(--orange);
}

.page-about .timeline__step {
  margin: 0 0 6px;
  font-size: .6875rem;
  letter-spacing: .2em;
  color: var(--orange);
}

.page-about .timeline__title {
  margin: 0;
  font-family: var(--font-display);
  font-size: clamp(1.0625rem, 1.7vw, 1.375rem);
  font-weight: 700;
  line-height: 1.35;
  letter-spacing: -.005em;
  color: var(--ink-980);
  max-width: 34ch;
}

.page-about .timeline__text {
  margin: 8px 0 0;
  max-width: 58ch;
  font-size: .9375rem;
  line-height: 1.78;
  color: var(--ink-800);
}

.page-about .timeline__more {
  margin: 0;
  max-height: 0;
  opacity: 0;
  overflow: hidden;
  max-width: 58ch;
  font-size: .875rem;
  line-height: 1.75;
  color: var(--silver-600);
  border-left: 2px solid var(--paper-300);
  padding-left: 0;
  transition: max-height .24s ease, opacity .24s ease, margin-top .24s ease, padding-left .24s ease;
}

.page-about .timeline__item:hover .timeline__more,
.page-about .timeline__item:focus-within .timeline__more {
  max-height: 12rem;
  opacity: 1;
  margin-top: 10px;
  padding-left: 12px;
}

/* ---------- 团队与班组 ---------- */

.page-about .crew-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(20px, 2.6vw, 34px);
  align-items: start;
}

.page-about .crew-stats {
  border-top: 1px solid var(--line-light);
}

.page-about .crew-stat {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 14px;
  padding: clamp(12px, 1.6vw, 17px) 2px;
  border-bottom: 1px solid var(--line-light);
}

.page-about .crew-stat__num {
  font-size: clamp(1.75rem, 4vw, 2.75rem);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -.02em;
  color: var(--ink-980);
}

.page-about .crew-stat__label {
  font-size: .875rem;
  color: var(--silver-600);
  text-align: right;
}

.page-about .crew-figure {
  margin: 0;
  position: relative;
  border: 1px solid var(--about-figure-line);
  background: var(--paper-200);
  padding: 6px;
}

.page-about .crew-figure img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 1 / 1;
  object-fit: cover;
  filter: saturate(.7);
}

.page-about .crew-figure figcaption {
  margin-top: 8px;
  padding: 0 2px;
  font-size: .75rem;
  line-height: 1.6;
  color: var(--silver-600);
}

.page-about .crew-schedule {
  margin-top: clamp(22px, 3vw, 36px);
}

.page-about .crew-schedule__title {
  margin: 0 0 14px;
  font-family: var(--font-display);
  font-size: clamp(1.0625rem, 1.6vw, 1.25rem);
  font-weight: 700;
  color: var(--ink-980);
}

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

.page-about .shift-list__row {
  display: grid;
  grid-template-columns: minmax(88px, 128px) minmax(0, 1fr);
  gap: 6px 18px;
  align-items: baseline;
  padding: clamp(11px, 1.5vw, 15px) 0;
  border-bottom: 1px solid var(--line-light);
}

.page-about .shift-list__key {
  font-size: .875rem;
  font-weight: 600;
  color: var(--orange);
  letter-spacing: -.01em;
}

.page-about .shift-list__val {
  font-size: .9375rem;
  line-height: 1.7;
  color: var(--ink-800);
}

.page-about .crew-schedule__note {
  margin: 14px 0 0;
  max-width: 62ch;
  font-size: .875rem;
  line-height: 1.75;
  color: var(--silver-600);
}

/* ---------- 口径与规范 ---------- */

.page-about .spec-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(20px, 2.6vw, 32px);
  align-items: start;
}

.page-about .spec-figure {
  margin: 0;
  border: 1px solid var(--about-figure-line);
  background: var(--ink-800);
  padding: 6px;
}

.page-about .spec-figure img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 3 / 4;
  object-fit: cover;
  filter: saturate(.6) contrast(1.05);
}

.page-about .spec-figure figcaption {
  margin-top: 8px;
  padding: 0 2px;
  font-size: .75rem;
  line-height: 1.6;
  color: var(--silver-400);
}

.page-about .spec-text {
  max-width: 62ch;
}

.page-about .spec-text .mono {
  font-weight: 700;
  color: var(--ink-980);
  border-bottom: 1px solid var(--orange);
}

.page-about .spec-versions {
  margin-top: clamp(22px, 3vw, 34px);
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 14px;
}

.page-about .spec-version {
  border: 1px solid var(--line-light);
  background: var(--paper-200);
  padding: clamp(14px, 1.8vw, 22px);
}

.page-about .spec-version--current {
  background: var(--ink-980);
  border-color: var(--ink-980);
  color: var(--paper-100);
  position: relative;
  overflow: hidden;
}

.page-about .spec-version--current::after {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 4px;
  height: 100%;
  background: var(--cyan);
}

.page-about .spec-version__tag {
  margin: 0;
  font-size: 1.375rem;
  font-weight: 700;
  letter-spacing: -.02em;
  color: var(--orange);
  line-height: 1;
}

.page-about .spec-version--current .spec-version__tag {
  color: var(--cyan);
}

.page-about .spec-version__state {
  margin: 8px 0 12px;
  font-size: .75rem;
  letter-spacing: .16em;
  color: var(--silver-600);
}

.page-about .spec-version--current .spec-version__state {
  color: var(--silver-400);
}

.page-about .spec-version__list {
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .spec-version__list li {
  position: relative;
  padding: 7px 0 7px 16px;
  font-size: .875rem;
  line-height: 1.7;
  color: var(--ink-800);
  border-top: 1px solid var(--line-light);
}

.page-about .spec-version--current .spec-version__list li {
  color: rgba(244, 238, 227, .82);
  border-top-color: var(--line-dark);
}

.page-about .spec-version__list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 15px;
  width: 6px;
  height: 1px;
  background: var(--orange);
}

.page-about .spec-version--current .spec-version__list li::before {
  background: var(--cyan);
}

.page-about .spec-version__list .mono {
  font-weight: 700;
  color: var(--paper-100);
}

.page-about .spec-foot {
  margin: clamp(18px, 2.2vw, 26px) 0 0;
  max-width: 62ch;
  font-size: .875rem;
  line-height: 1.75;
  color: var(--silver-600);
}

/* ---------- 备案与主体 ---------- */

.page-about .record-list {
  margin: 0;
  border-top: 1px solid var(--line-light);
  display: grid;
  grid-template-columns: minmax(0, 1fr);
}

.page-about .record-row {
  display: grid;
  grid-template-columns: 88px minmax(0, 1fr);
  gap: 6px 16px;
  align-items: baseline;
  padding: clamp(12px, 1.6vw, 16px) 0;
  border-bottom: 1px solid var(--line-light);
}

.page-about .record-row dt {
  font-size: .8125rem;
  color: var(--silver-600);
}

.page-about .record-row dd {
  margin: 0;
  font-size: .9375rem;
  line-height: 1.72;
  color: var(--ink-980);
  word-break: break-word;
}

.page-about .record-row dd .mono {
  font-weight: 600;
  letter-spacing: -.01em;
}

.page-about .record-row .copy-btn {
  margin-left: 10px;
  vertical-align: baseline;
}

.page-about .record-boundary {
  margin-top: clamp(18px, 2.4vw, 28px);
  background: var(--paper-200);
  border-top: 2px solid var(--ink-980);
  padding: clamp(14px, 1.8vw, 22px) clamp(16px, 2vw, 24px);
  max-width: 68ch;
}

.page-about .record-boundary p {
  margin: 0 0 .9em;
  font-size: .875rem;
  line-height: 1.78;
  color: var(--ink-800);
}

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

/* ---------- 断点 ---------- */

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

@media (min-width: 760px) {
  .page-about .spec-grid {
    grid-template-columns: minmax(190px, 268px) minmax(0, 1fr);
    gap: clamp(24px, 3vw, 40px);
  }

  .page-about .spec-versions {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .page-about .record-list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    column-gap: clamp(22px, 3vw, 48px);
  }
}

@media (min-width: 900px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 1.08fr) minmax(0, 1fr);
  }

  .page-about .about-body {
    grid-template-columns: var(--about-rail) minmax(0, 1fr);
  }

  .page-about .about-rail {
    position: sticky;
    top: 108px;
    border-bottom: 0;
    border-left: 1px solid var(--line-light);
    padding: 2px 0 2px 18px;
  }

  .page-about .about-rail__list {
    display: block;
    overflow: visible;
    margin-top: 14px;
  }

  .page-about .about-rail__list li + li {
    margin-top: 6px;
  }

  .page-about .about-rail__link {
    display: block;
    border: 0;
    border-left: 2px solid transparent;
    padding: 5px 0 5px 12px;
    margin-left: -19px;
    white-space: normal;
    background: transparent;
  }

  .page-about .about-rail__link:hover,
  .page-about .about-rail__link[aria-current="true"] {
    background: transparent;
    border-left-color: var(--orange);
    color: var(--ink-980);
  }

  .page-about .crew-grid {
    grid-template-columns: minmax(0, 1.08fr) minmax(0, .92fr);
    gap: clamp(26px, 3.4vw, 48px);
  }

  .page-about .timeline__item::before {
    left: 0;
  }

  .page-about .timeline::before {
    left: 5px;
  }
}

@media (min-width: 1180px) {
  .page-about .spec-grid {
    grid-template-columns: minmax(220px, 300px) minmax(0, 1fr);
  }
}

@media (hover: none) {
  .page-about .timeline__more {
    max-height: none;
    opacity: 1;
    margin-top: 10px;
    padding-left: 12px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .timeline__more,
  .page-about .about-rail__link,
  .page-about .timeline__item::before {
    transition: none;
  }
}