.page-about {
  --about-rail-w: 268px;
  --about-gap: 44px;
}

/* ---------- 页首 ---------- */
.page-about .about-hero {
  padding: 26px 0 10px;
  position: relative;
}

.page-about .about-hero__inner {
  display: grid;
  gap: 26px;
}

.page-about .about-hero__text {
  min-width: 0;
}

.page-about .about-hero__note {
  margin-top: 14px;
  color: var(--muted);
  font-size: 15px;
  line-height: 1.8;
  max-width: 62ch;
}

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

.page-about .about-hero__facts {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: 30px 0 0;
  background: var(--hair);
  border: 1px solid var(--hair);
}

.page-about .about-fact {
  background: var(--panel);
  padding: 14px 16px 12px;
}

.page-about .about-fact__label {
  color: var(--muted);
  font-size: 12px;
  letter-spacing: .08em;
  margin: 0;
}

.page-about .about-fact__value {
  margin: 6px 0 0;
  font-family: var(--font-numeric);
  font-size: clamp(22px, 4vw, 30px);
  font-weight: 600;
  color: var(--text);
  letter-spacing: .01em;
}

/* ---------- 主布局 ---------- */
.page-about .about-layout {
  display: block;
  margin-top: 18px;
  padding-bottom: 64px;
}

.page-about .about-main {
  min-width: 0;
}

/* ---------- 左侧常驻目录 ---------- */
.page-about .about-rail {
  margin-bottom: 28px;
  border: 1px solid var(--hair);
  background: var(--moss);
  padding: 14px 16px 16px;
}

.page-about .about-rail .index-rail__title {
  font-family: var(--font-display);
  font-size: 12px;
  letter-spacing: .1em;
  color: var(--muted);
  margin: 0 0 10px;
}

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

.page-about .about-rail .index-rail__item {
  flex: 0 0 auto;
  border: 0;
  padding: 0;
}

.page-about .about-rail .index-rail__item a {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 7px 10px;
  border: 1px solid var(--hair);
  background: var(--ink);
  color: var(--text);
  font-size: 13px;
  text-decoration: none;
  white-space: nowrap;
  transition: border-color 160ms var(--ease), color 160ms var(--ease), background-color 160ms var(--ease);
}

.page-about .about-rail .index-rail__item a:hover,
.page-about .about-rail .index-rail__item a:focus-visible {
  border-color: var(--accent);
  color: var(--accent);
  background: var(--accent-soft);
}

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

.page-about .about-rail .index-rail__item a:hover .about-rail__num {
  color: var(--accent);
}

/* ---------- 章节 ---------- */
.page-about .about-section {
  padding: 34px 0 30px;
  border-top: 1px solid var(--hair);
}

.page-about .about-section--last {
  border-bottom: 1px solid var(--hair);
}

.page-about .about-section__head {
  display: flex;
  align-items: baseline;
  gap: 14px;
  margin-bottom: 16px;
}

.page-about .about-section__num {
  font-family: var(--font-numeric);
  font-size: 13px;
  color: var(--accent);
  letter-spacing: .06em;
  flex: 0 0 auto;
  padding-top: 2px;
}

.page-about .about-section__title {
  font-family: var(--font-display);
  font-size: clamp(22px, 3.2vw, 28px);
  letter-spacing: .04em;
  margin: 0;
  color: var(--text);
  font-weight: 700;
}

.page-about .about-section__body > p {
  margin: 0 0 16px;
  max-width: 74ch;
}

.page-about .about-section__body a {
  color: var(--accent);
  text-decoration: none;
  border-bottom: 1px solid var(--hair-strong);
  transition: border-color 150ms var(--ease);
}

.page-about .about-section__body a:hover {
  border-bottom-color: var(--accent);
}

/* ---------- 立场双栏 ---------- */
.page-about .about-split {
  display: grid;
  gap: 14px;
  margin: 4px 0 18px;
}

.page-about .about-split__col {
  padding: 18px 18px 16px;
  min-width: 0;
}

.page-about .about-split__col--bound {
  background: linear-gradient(180deg, rgba(90, 31, 46, .28), rgba(18, 32, 51, .9));
}

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

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

.page-about .about-list li {
  position: relative;
  padding: 8px 0 8px 16px;
  border-top: 1px solid var(--hair);
  font-size: 15px;
  line-height: 1.7;
  color: var(--text);
}

.page-about .about-list li:first-child {
  border-top: 0;
}

.page-about .about-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 17px;
  width: 8px;
  height: 1px;
  background: var(--accent);
}

.page-about .about-list--bound li::before {
  background: var(--orange);
}

/* ---------- 流程 SVG ---------- */
.page-about .about-flow {
  display: block;
  width: 100%;
  height: auto;
  margin: 6px 0 22px;
  overflow: visible;
}

.page-about .about-flow__node rect {
  fill: var(--panel);
  stroke: var(--hair);
  stroke-width: 1;
}

.page-about .about-flow__node--accent rect {
  stroke: var(--accent);
  fill: var(--accent-soft);
}

.page-about .about-flow__num {
  fill: var(--muted);
  font-family: var(--font-numeric);
  font-size: 12px;
  letter-spacing: .1em;
}

.page-about .about-flow__label {
  fill: var(--text);
  font-family: var(--font-display);
  font-size: 15px;
  letter-spacing: .04em;
}

.page-about .about-flow__meta {
  fill: var(--muted);
  font-family: var(--font-numeric);
  font-size: 11px;
}

.page-about .about-flow__link {
  stroke: var(--hair-strong);
  stroke-width: 1;
}

.page-about .about-flow__arrow {
  fill: var(--hair-strong);
}

.page-about .about-steps {
  margin-bottom: 22px;
}

.page-about .about-step {
  padding: 16px 16px 14px;
  min-width: 0;
  display: flex;
  flex-direction: column;
}

.page-about .about-step__tag {
  margin: 0 0 10px;
}

.page-about .about-step__title {
  font-family: var(--font-display);
  font-size: 17px;
  letter-spacing: .04em;
  margin: 0 0 10px;
  color: var(--text);
}

.page-about .about-step p {
  margin: 0 0 10px;
  font-size: 14.5px;
  line-height: 1.72;
}

.page-about .about-step__out {
  margin-top: auto;
  padding-top: 10px;
  border-top: 1px solid var(--hair);
  color: var(--muted);
  font-size: 13.5px;
}

.page-about .about-step__out-label {
  display: inline-block;
  margin-right: 8px;
  color: var(--orange);
  font-size: 12px;
  letter-spacing: .08em;
}

.page-about .about-pipeline-figure,
.page-about .about-version-figure {
  margin: 0;
}

/* ---------- 口径词典 ---------- */
.page-about .about-glossary {
  margin: 4px 0 18px;
  border-top: 1px solid var(--hair);
}

.page-about .about-glossary__item {
  display: grid;
  gap: 6px;
  padding: 16px 0;
  border-bottom: 1px solid var(--hair);
  transition: background-color 160ms var(--ease);
}

.page-about .about-glossary__item:hover {
  background: rgba(18, 32, 51, .55);
}

.page-about .about-glossary__term {
  font-family: var(--font-numeric);
  font-size: 15px;
  color: var(--accent);
  letter-spacing: .02em;
  padding-left: 12px;
  border-left: 2px solid var(--hair);
  transition: border-color 160ms var(--ease);
}

.page-about .about-glossary__item:hover .about-glossary__term {
  border-left-color: var(--accent);
}

.page-about .about-glossary__def {
  margin: 0;
  min-width: 0;
}

.page-about .about-glossary__def p {
  margin: 0 0 8px;
  font-size: 15px;
  line-height: 1.75;
}

.page-about .about-glossary__extra {
  color: var(--muted);
  font-size: 13.5px;
  line-height: 1.7;
}

.page-about .about-inline-correction {
  font-size: 14px;
  color: var(--muted);
  border-left: 2px solid var(--orange);
  padding-left: 12px;
  margin: 0;
}

/* ---------- 版本时间线 ---------- */
.page-about .about-timeline {
  list-style: none;
  margin: 6px 0 24px;
  padding: 0 0 0 20px;
  position: relative;
}

.page-about .about-timeline::before {
  content: "";
  position: absolute;
  left: 3px;
  top: 8px;
  bottom: 8px;
  width: 1px;
  background: var(--hair-strong);
}

.page-about .about-timeline__item {
  position: relative;
  padding: 0 0 26px 12px;
}

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

.page-about .about-timeline__dot {
  position: absolute;
  left: -20px;
  top: 6px;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--panel);
  border: 1px solid var(--hair-strong);
}

.page-about .about-timeline__dot--accent {
  background: var(--accent);
  border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-soft);
}

.page-about .about-timeline__ver {
  font-family: var(--font-numeric);
  font-size: 12.5px;
  letter-spacing: .08em;
  color: var(--muted);
  margin: 0 0 6px;
}

.page-about .about-timeline__name {
  font-family: var(--font-display);
  font-size: 18px;
  letter-spacing: .04em;
  margin: 0 0 8px;
  color: var(--text);
}

.page-about .about-timeline__body p {
  margin: 0 0 8px;
  font-size: 15px;
  line-height: 1.75;
}

.page-about .about-timeline__edge {
  color: var(--muted);
  font-size: 13.5px;
  border-top: 1px dashed var(--hair);
  padding-top: 8px;
}

/* ---------- 团队 ---------- */
.page-about .about-team {
  margin-top: 4px;
}

.page-about .about-team__card {
  padding: 16px 16px 14px;
  min-width: 0;
}

.page-about .about-team__count {
  font-family: var(--font-numeric);
  font-size: clamp(30px, 6vw, 42px);
  line-height: 1;
  color: var(--accent);
  margin: 0 0 10px;
  letter-spacing: -.01em;
}

.page-about .about-team__role {
  font-family: var(--font-display);
  font-size: 16px;
  letter-spacing: .05em;
  margin: 0 0 8px;
  color: var(--text);
}

.page-about .about-team__desc {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.72;
  color: var(--muted);
}

/* ---------- 纠错 ---------- */
.page-about .about-correct {
  padding: 20px 18px 18px;
  border-left: 2px solid var(--accent);
}

.page-about .about-correct__lede {
  margin: 0 0 16px;
  font-size: 15.5px;
  line-height: 1.75;
  max-width: 68ch;
}

.page-about .about-correct__facts {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: 0 0 16px;
  background: var(--hair);
  border: 1px solid var(--hair);
}

.page-about .about-correct__facts > div {
  background: var(--ink);
  padding: 12px 14px;
}

.page-about .about-correct__facts dt {
  color: var(--muted);
  font-size: 12px;
  letter-spacing: .06em;
  margin-bottom: 6px;
}

.page-about .about-correct__facts dd {
  margin: 0;
  font-family: var(--font-numeric);
  font-size: 18px;
  color: var(--text);
}

.page-about .about-correct__hint {
  margin: 0 0 16px;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.7;
}

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

/* ---------- 边界 ---------- */
.page-about .about-bounds {
  list-style: none;
  margin: 0;
  padding: 0;
  counter-reset: bound;
}

.page-about .about-bounds li {
  counter-increment: bound;
  position: relative;
  padding: 12px 0 12px 34px;
  border-top: 1px solid var(--hair);
  font-size: 15px;
  line-height: 1.75;
  color: var(--text);
}

.page-about .about-bounds li::before {
  content: counter(bound, decimal-leading-zero);
  position: absolute;
  left: 0;
  top: 13px;
  font-family: var(--font-numeric);
  font-size: 12px;
  color: var(--orange);
  letter-spacing: .06em;
}

/* ---------- 响应式 ---------- */
@media (min-width: 560px) {
  .page-about .about-hero__facts {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

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

  .page-about .about-correct__facts {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

@media (min-width: 720px) {
  .page-about .about-glossary__item {
    grid-template-columns: 190px minmax(0, 1fr);
    gap: 24px;
    align-items: start;
  }
}

@media (min-width: 900px) {
  .page-about .about-hero {
    padding: 34px 0 14px;
  }

  .page-about .about-hero__inner {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    gap: 42px;
    align-items: start;
  }

  .page-about .about-section {
    padding: 44px 0 38px;
  }
}

@media (min-width: 1000px) {
  .page-about .about-layout {
    display: grid;
    grid-template-columns: var(--about-rail-w) minmax(0, 1fr);
    gap: var(--about-gap);
    align-items: start;
  }

  .page-about .about-rail {
    position: sticky;
    top: 22px;
    margin-bottom: 0;
  }

  .page-about .about-rail__list {
    display: block;
    overflow: visible;
  }

  .page-about .about-rail .index-rail__item {
    display: block;
  }

  .page-about .about-rail .index-rail__item a {
    display: flex;
    width: 100%;
    justify-content: flex-start;
    border: 0;
    border-left: 2px solid var(--hair);
    background: transparent;
    padding: 8px 10px;
    white-space: normal;
    font-size: 13.5px;
    line-height: 1.5;
  }

  .page-about .about-rail .index-rail__item a:hover,
  .page-about .about-rail .index-rail__item a:focus-visible {
    border-left-color: var(--accent);
    background: var(--accent-soft);
  }
}

@media (min-width: 1180px) {
  .page-about .about-section__body {
    padding-right: 8px;
  }
}