.page-about {
  --about-rail: 250px;
  --about-tint: rgba(110, 27, 35, 0.06);
}

/* ---------- 首屏 ---------- */
.page-about .about-mast__inner {
  position: relative;
  padding: 36px 0 28px;
}

.page-about .about-mast h1 {
  font-family: var(--serif);
  font-size: clamp(30px, 6.6vw, 54px);
  line-height: 1.15;
  letter-spacing: 0.005em;
  margin: 14px 0 0;
  max-width: 17em;
}

.page-about .about-lede {
  font-size: 17px;
  line-height: 1.75;
  color: var(--ink-soft);
  max-width: 40em;
  margin: 20px 0 0;
}

.page-about .about-meta {
  list-style: none;
  margin: 26px 0 0;
  padding: 14px 0 0;
  border-top: 1px solid var(--line);
  display: flex;
  flex-wrap: wrap;
  gap: 6px 26px;
  font-family: var(--mono);
  font-size: 13px;
  line-height: 1.5;
  color: var(--ink-soft);
}

.page-about .about-seal {
  display: none;
}

@media (min-width: 900px) {
  .page-about .about-seal {
    display: inline-block;
    position: absolute;
    right: 6px;
    top: 64px;
    transform: rotate(-7deg);
    font-size: 14px;
  }
}

/* ---------- 两列骨架 ---------- */
.page-about .about-layout {
  padding-bottom: 72px;
}

.page-about .about-toc {
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  padding: 14px 0 10px;
  margin-bottom: 4px;
}

.page-about .about-toc__label {
  margin: 0 0 10px;
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.22em;
  color: var(--red);
}

.page-about .about-toc .toc__list {
  list-style: none;
  margin: 0;
  padding: 0 0 6px;
  display: flex;
  gap: 8px;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
}

.page-about .about-toc .toc__link {
  display: block;
  white-space: nowrap;
  font-size: 14px;
  line-height: 1.4;
  padding: 5px 11px;
  border: 1px solid transparent;
  color: var(--ink-soft);
  text-decoration: none;
}

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

.page-about .about-toc .toc__link[aria-current="true"] {
  color: var(--red);
  background: var(--about-tint);
  border-color: var(--line);
}

@media (min-width: 1024px) {
  .page-about .about-layout {
    display: grid;
    grid-template-columns: var(--about-rail) minmax(0, 1fr);
    gap: 64px;
    align-items: start;
  }

  .page-about .about-toc {
    position: sticky;
    top: 28px;
    border-top: none;
    border-bottom: none;
    border-left: 2px solid var(--red);
    padding: 4px 0 4px 16px;
    margin-bottom: 0;
  }

  .page-about .about-toc .toc__list {
    flex-direction: column;
    gap: 2px;
    overflow: visible;
    padding-bottom: 0;
  }

  .page-about .about-toc .toc__link {
    white-space: normal;
    padding: 6px 8px;
  }
}

/* ---------- 章节 ---------- */
.page-about .about-section {
  padding: 44px 0 16px;
  border-top: 1px solid var(--line-soft);
  scroll-margin-top: 88px;
}

.page-about .about-section:first-child {
  border-top: none;
  padding-top: 12px;
}

.page-about .about-head {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  justify-content: space-between;
  gap: 6px 20px;
  margin-bottom: 18px;
}

.page-about .about-section h2 {
  font-family: var(--serif);
  font-size: clamp(24px, 4.4vw, 36px);
  line-height: 1.25;
  margin: 0;
}

.page-about .about-head__note {
  margin: 0;
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.18em;
  color: var(--red);
}

.page-about .about-section p {
  font-size: 17px;
  line-height: 1.75;
  margin: 0 0 18px;
  max-width: 40em;
}

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

.page-about .about-section a {
  color: var(--red);
  text-decoration: underline;
  text-decoration-color: var(--gold);
  text-underline-offset: 3px;
}

.page-about .about-section a:hover {
  color: var(--red-2);
}

.page-about .about-section h3 {
  font-family: var(--serif);
  font-size: 20px;
  line-height: 1.35;
  margin: 0 0 8px;
}

.page-about .about-section .figure {
  margin: 0 0 26px;
}

.page-about .about-section .figure__img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  object-fit: cover;
}

.page-about .about-note {
  font-size: 14px;
  line-height: 1.7;
  color: var(--ink-soft);
  max-width: 40em;
  margin: 20px 0 0;
}

/* ---------- 四条原则 ---------- */
.page-about .principle-list {
  display: grid;
  gap: 12px;
  margin-top: 26px;
}

.page-about .principle {
  background: var(--paper-2);
}

.page-about .principle .panel__summary {
  display: flex;
  align-items: baseline;
  flex-wrap: wrap;
  gap: 6px 16px;
  cursor: pointer;
}

.page-about .principle__num {
  font-family: var(--serif);
  font-size: 26px;
  font-weight: 700;
  line-height: 1.1;
  color: var(--red);
  min-width: 2ch;
}

.page-about .principle__title {
  font-family: var(--serif);
  font-size: 20px;
  line-height: 1.35;
  flex: 1 1 12em;
}

.page-about .principle__seal {
  transform: rotate(-5deg);
  font-size: 12px;
  margin-left: auto;
}

.page-about .principle .panel__body p:first-child {
  margin-top: 4px;
}

/* ---------- 整理流程 ---------- */
.page-about .flow {
  list-style: none;
  margin: 26px 0 0;
  padding: 0 0 0 28px;
  position: relative;
}

.page-about .flow::before {
  content: "";
  position: absolute;
  left: 5px;
  top: 8px;
  bottom: 20px;
  width: 1px;
  background: linear-gradient(to bottom, var(--gold), rgba(201, 164, 92, 0.12));
}

.page-about .flow__step {
  position: relative;
  padding-bottom: 26px;
}

.page-about .flow__step::before {
  content: "";
  position: absolute;
  left: -28px;
  top: 7px;
  width: 11px;
  height: 11px;
  border-radius: 50%;
  background: var(--paper);
  border: 2px solid var(--pine);
}

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

.page-about .flow__num {
  display: block;
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.2em;
  color: var(--gold);
  margin-bottom: 2px;
}

.page-about .flow__step p {
  font-size: 16px;
  line-height: 1.75;
  margin: 0;
  max-width: 38em;
}

/* ---------- 团队 ---------- */
.page-about .crew {
  list-style: none;
  margin: 24px 0 0;
  padding: 0;
  border-top: 1px solid var(--line-soft);
}

.page-about .crew__row {
  display: grid;
  grid-template-columns: 1fr auto auto;
  align-items: baseline;
  gap: 4px 12px;
  padding: 13px 2px;
  border-bottom: 1px solid var(--line-soft);
}

.page-about .crew__role {
  font-family: var(--sans);
  font-size: 16px;
  color: var(--ink);
}

.page-about .crew__num {
  font-family: var(--serif);
  font-size: 30px;
  line-height: 1;
  font-weight: 700;
  color: var(--red);
}

.page-about .crew__unit {
  font-size: 13px;
  color: var(--ink-soft);
}

.page-about .about-stats {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
  gap: 22px 24px;
  margin-top: 30px;
  padding-top: 24px;
  border-top: 1px solid var(--line);
}

.page-about .about-stats .stat {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.page-about .about-stats .stat__num {
  font-family: var(--serif);
  font-size: 30px;
  line-height: 1.1;
  font-weight: 700;
  color: var(--ink);
}

.page-about .about-stats .stat__label {
  font-family: var(--mono);
  font-size: 13px;
  line-height: 1.5;
  color: var(--ink-soft);
}

/* ---------- 年表 ---------- */
.page-about .year-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 22px 0 26px;
}

.page-about .year-nav a {
  font-family: var(--mono);
  font-size: 13px;
  letter-spacing: 0.08em;
  padding: 5px 13px;
  border: 1px solid var(--line);
  color: var(--red);
  text-decoration: none;
  transition: background 200ms var(--ease), color 200ms var(--ease), border-color 200ms var(--ease);
}

.page-about .year-nav a:hover,
.page-about .year-nav a:focus-visible {
  background: var(--red);
  border-color: var(--red);
  color: var(--paper);
}

.page-about .timeline {
  list-style: none;
  margin: 32px 0 0;
  padding: 0 0 0 30px;
  position: relative;
}

.page-about .timeline::before {
  content: "";
  position: absolute;
  left: 5px;
  top: 10px;
  bottom: 12px;
  width: 1px;
  background: linear-gradient(to bottom, var(--gold), rgba(201, 164, 92, 0.15));
}

.page-about .timeline__item {
  position: relative;
  padding-bottom: 30px;
  scroll-margin-top: 96px;
}

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

.page-about .timeline__item::before {
  content: "";
  position: absolute;
  left: -30px;
  top: 9px;
  width: 11px;
  height: 11px;
  border-radius: 50%;
  background: var(--paper);
  border: 2px solid var(--green);
  transition: background 200ms var(--ease);
}

.page-about .timeline__item:target::before {
  background: var(--gold);
  border-color: var(--red);
}

.page-about .timeline__ver {
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.2em;
  color: var(--red);
  margin: 0 0 4px;
  max-width: none;
}

.page-about .timeline__item h3 {
  margin: 0 0 8px;
}

.page-about .timeline__item p {
  font-size: 16px;
  line-height: 1.75;
  margin: 0;
  max-width: 38em;
}

/* ---------- 资质 ---------- */
.page-about .about-quote {
  margin: 0 0 26px;
  padding: 26px 22px;
  background: var(--paper-2);
  border-left: 3px solid var(--gold);
  box-shadow: var(--shadow-paper);
}

.page-about .about-quote p {
  font-family: var(--serif);
  font-size: clamp(19px, 3.2vw, 25px);
  line-height: 1.6;
  color: var(--ink);
  margin: 0;
  max-width: 26em;
}

.page-about .facts {
  margin: 0 0 26px;
  padding: 0;
  border-top: 1px solid var(--line);
}

.page-about .facts__row {
  display: grid;
  grid-template-columns: 6em minmax(0, 1fr);
  gap: 4px 16px;
  padding: 12px 2px;
  border-bottom: 1px solid var(--line-soft);
}

.page-about .facts__row dt {
  font-family: var(--mono);
  font-size: 13px;
  letter-spacing: 0.08em;
  color: var(--ink-soft);
}

.page-about .facts__row dd {
  margin: 0;
  font-size: 16px;
  line-height: 1.6;
  color: var(--ink);
  word-break: break-word;
}

@media (min-width: 720px) {
  .page-about .about-mast__inner {
    padding: 56px 0 40px;
  }

  .page-about .about-section {
    padding: 56px 0 20px;
  }

  .page-about .about-section:first-child {
    padding-top: 16px;
  }

  .page-about .principle .panel__summary {
    gap: 6px 20px;
  }
}

@media (min-width: 1024px) {
  .page-about .about-layout {
    padding-bottom: 104px;
  }

  .page-about .about-section {
    padding: 64px 0 24px;
  }

  .page-about .about-section h3 {
    font-size: 21px;
  }

  .page-about .about-stats .stat__num {
    font-size: 34px;
  }
}

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