.page-about {
  --about-index-w: 74px;
  --about-gap: 44px;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--font-sans);
}

.page-about .about-wrap {
  padding-top: 20px;
  padding-bottom: 64px;
}

.page-about .about-crumb {
  font-size: 13px;
  color: var(--ink-soft);
  margin-bottom: 18px;
  letter-spacing: .04em;
}

.page-about .about-crumb a {
  color: var(--ink-soft);
  text-decoration: none;
}

.page-about .about-crumb a:hover,
.page-about .about-crumb a:focus-visible {
  color: var(--brass);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  padding: 8px 0 26px;
  border-bottom: 1px solid var(--line);
}

.page-about .about-hero__kicker {
  margin: 0 0 12px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .3em;
  color: var(--brass);
}

.page-about .about-hero__title {
  margin: 0 0 18px;
  max-width: 15em;
  font-family: var(--font-serif);
  font-weight: 800;
  font-size: 34px;
  line-height: 1.24;
  letter-spacing: .04em;
  color: var(--teal-900);
}

.page-about .about-lead {
  margin: 0 0 26px;
  max-width: var(--measure);
  font-size: 17px;
  line-height: 1.92;
  color: var(--ink);
}

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

.page-about .about-facts__item {
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding: 14px 14px 12px;
  background: var(--paper);
}

.page-about .about-facts__num {
  font-family: var(--font-mono);
  font-size: 21px;
  font-weight: 600;
  line-height: 1.2;
  color: var(--teal-900);
}

.page-about .about-facts__label {
  font-size: 12.5px;
  line-height: 1.5;
  color: var(--ink-soft);
  letter-spacing: .04em;
}

/* ---------- 竖排索引 + 窄栏正文 ---------- */
.page-about .about-shell {
  margin-top: 28px;
}

.page-about .about-index {
  display: flex;
  gap: 8px;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  padding-bottom: 10px;
  margin-bottom: 14px;
  border-bottom: 1px solid var(--line);
}

.page-about .about-index__link {
  flex: 0 0 auto;
  padding: 6px 13px;
  border: 1px solid var(--line);
  border-radius: 2px;
  background: var(--parchment);
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: .1em;
  color: var(--ink-soft);
  text-decoration: none;
  white-space: nowrap;
  transition: color .2s ease-out, border-color .2s ease-out, background .2s ease-out;
}

.page-about .about-index__link:hover,
.page-about .about-index__link:focus-visible {
  color: var(--teal-900);
  border-color: var(--brass);
  background: var(--paper);
}

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

/* ---------- 章节骨架 ---------- */
.page-about .about-section {
  padding: 34px 0;
  scroll-margin-top: 132px;
}

.page-about .about-section + .about-section {
  border-top: 1px solid var(--line);
}

.page-about .about-section--parchment {
  background: var(--parchment);
  border-left: 3px solid var(--brass);
  padding: 28px 18px;
}

.page-about .about-section--dark {
  background: linear-gradient(158deg, var(--teal-900) 0%, var(--teal-700) 100%);
  border-left: 3px solid var(--brass);
  border-radius: 4px;
  padding: 32px 20px;
}

.page-about .about-section--dark .about-head__title {
  color: var(--paper);
}

.page-about .about-section--dark .about-prose p {
  color: rgba(245, 241, 232, .86);
}

.page-about .about-head {
  margin-bottom: 18px;
}

.page-about .about-head__num {
  display: block;
  margin-bottom: 6px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .26em;
  color: var(--brass);
}

.page-about .about-head__title {
  margin: 0;
  font-family: var(--font-serif);
  font-weight: 800;
  font-size: 24px;
  line-height: 1.36;
  letter-spacing: .04em;
  color: var(--teal-900);
}

.page-about .about-prose p {
  margin: 0 0 16px;
  max-width: var(--measure);
  font-size: 16.5px;
  line-height: 1.92;
  color: var(--ink);
}

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

/* ---------- 命名习惯 ---------- */
.page-about .about-habits {
  list-style: none;
  counter-reset: habit;
  margin: 22px 0 22px;
  padding: 0;
  display: grid;
  gap: 14px;
  max-width: var(--measure);
}

.page-about .about-habits li {
  counter-increment: habit;
  position: relative;
  padding-left: 46px;
  font-size: 15.5px;
  line-height: 1.88;
  color: var(--ink-soft);
}

.page-about .about-habits li strong {
  display: block;
  margin-bottom: 2px;
  font-family: var(--font-serif);
  font-weight: 700;
  font-size: 16.5px;
  letter-spacing: .03em;
  color: var(--teal-900);
}

.page-about .about-habits li::before {
  content: counter(habit, decimal-leading-zero);
  position: absolute;
  left: 0;
  top: 3px;
  padding: 2px 6px;
  border: 1px solid var(--line);
  border-radius: 2px;
  background: var(--paper);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .06em;
  color: var(--brass);
}

/* ---------- 批次工序 ---------- */
.page-about .about-flow {
  list-style: none;
  counter-reset: flow;
  margin: 24px 0 26px;
  padding: 0;
  max-width: var(--measure);
}

.page-about .about-flow__item {
  counter-increment: flow;
  position: relative;
  padding: 0 0 22px 48px;
}

.page-about .about-flow__item::before {
  content: counter(flow, decimal-leading-zero);
  position: absolute;
  left: 0;
  top: 0;
  width: 30px;
  padding: 2px 0;
  border: 1px solid var(--line);
  border-radius: 2px;
  background: var(--paper);
  text-align: center;
  font-family: var(--font-mono);
  font-size: 12.5px;
  color: var(--brass);
}

.page-about .about-flow__item:not(:last-child)::after {
  content: "";
  position: absolute;
  left: 15px;
  top: 30px;
  bottom: 0;
  width: 1px;
  background: var(--line);
}

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

.page-about .about-flow__title {
  display: block;
  margin-bottom: 4px;
  font-family: var(--font-serif);
  font-weight: 700;
  font-size: 17px;
  letter-spacing: .04em;
  color: var(--teal-900);
}

.page-about .about-flow__text {
  display: block;
  font-size: 15.5px;
  line-height: 1.86;
  color: var(--ink-soft);
}

/* ---------- 图片 ---------- */
.page-about .about-photo {
  margin: 26px 0 0;
}

.page-about .about-photo__frame {
  position: relative;
  padding: 0 8px 8px 0;
}

.page-about .about-photo__frame::before {
  content: "";
  position: absolute;
  left: 8px;
  top: 8px;
  right: 0;
  bottom: 0;
  border: 1px solid var(--line);
  pointer-events: none;
}

.page-about .about-photo__frame img {
  position: relative;
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  border: 1px solid var(--line);
  background: var(--parchment);
  object-fit: cover;
  filter: saturate(.94) contrast(1.02);
}

.page-about .about-photo__cap {
  margin: 12px 0 0;
  max-width: var(--measure);
  font-family: var(--font-mono);
  font-size: 12.5px;
  line-height: 1.7;
  letter-spacing: .02em;
  color: var(--ink-soft);
}

/* ---------- 时间轴 ---------- */
.page-about .about-timeline {
  display: block;
  width: 100%;
  height: auto;
  margin: 10px 0 26px;
}

.page-about .tl-line {
  stroke: var(--line);
  stroke-width: 1.5;
  stroke-dasharray: 5 6;
}

.page-about .tl-dot {
  stroke-width: 3;
}

.page-about .tl-dot--1 {
  fill: var(--flag-yellow);
  stroke: var(--flag-yellow);
}

.page-about .tl-dot--2 {
  fill: var(--flag-green);
  stroke: var(--flag-green);
}

.page-about .tl-dot--3 {
  fill: var(--brass);
  stroke: var(--brass);
}

.page-about .tl-label {
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: .06em;
  fill: var(--ink-soft);
}

/* ---------- 阶段折叠 ---------- */
.page-about .about-stages {
  max-width: var(--measure);
}

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

.page-about .about-stage:last-child {
  border-bottom: 1px solid var(--line);
}

.page-about .about-stage .kit-fold__head {
  width: 100%;
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 16px 2px;
  background: transparent;
  border: 0;
  text-align: left;
  cursor: pointer;
  color: var(--teal-900);
  font-family: var(--font-serif);
  font-weight: 700;
  font-size: 17px;
  letter-spacing: .04em;
  transition: color .2s ease-out;
}

.page-about .about-stage .kit-fold__head:hover,
.page-about .about-stage .kit-fold__head:focus-visible {
  color: var(--brass);
}

.page-about .about-stage .kit-fold__marker {
  flex: 0 0 auto;
  width: 9px;
  height: 9px;
  border: 1px solid var(--brass);
  transform: rotate(45deg);
  transition: background .2s ease-out;
}

.page-about .about-stage .kit-fold[data-open] .kit-fold__marker {
  background: var(--brass);
}

.page-about .about-stage .kit-fold__panel {
  padding: 0 2px 20px 21px;
  font-size: 15.5px;
  line-height: 1.88;
  color: var(--ink-soft);
}

/* ---------- 团队 ---------- */
.page-about .about-crew {
  list-style: none;
  margin: 22px 0 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.page-about .about-crew__item {
  border: 1px solid var(--line);
  border-top: 3px solid var(--teal-300);
  background: var(--paper);
  padding: 16px 14px 18px;
  transition: border-color .24s ease-out, transform .24s ease-out, box-shadow .24s ease-out;
}

.page-about .about-crew__item:nth-child(2) {
  border-top-color: var(--brass);
}

.page-about .about-crew__item:nth-child(3) {
  border-top-color: var(--flag-green);
}

.page-about .about-crew__item:nth-child(4) {
  border-top-color: var(--flag-red);
}

.page-about .about-crew__item:hover,
.page-about .about-crew__item:focus-within {
  border-color: var(--teal-700);
  transform: translateY(-3px);
  box-shadow: var(--shadow-1);
}

.page-about .about-crew__name {
  display: block;
  margin-bottom: 8px;
  font-family: var(--font-serif);
  font-weight: 700;
  font-size: 17px;
  letter-spacing: .04em;
  color: var(--teal-900);
}

.page-about .about-crew__role {
  display: block;
  font-size: 15px;
  line-height: 1.84;
  color: var(--ink-soft);
}

/* ---------- 覆盖数字 ---------- */
.page-about .about-stats {
  list-style: none;
  margin: 22px 0 26px;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 18px 14px;
}

.page-about .about-stat {
  border-top: 2px solid var(--brass);
  padding-top: 10px;
}

.page-about .about-stat__num {
  display: block;
  font-family: var(--font-mono);
  font-size: 25px;
  font-weight: 600;
  line-height: 1.2;
  color: var(--paper);
}

.page-about .about-stat__label {
  display: block;
  margin-top: 5px;
  font-size: 13px;
  line-height: 1.6;
  letter-spacing: .04em;
  color: rgba(245, 241, 232, .74);
}

/* ---------- 备案小签 ---------- */
.page-about .about-plate {
  display: grid;
  gap: 12px;
  margin: 24px 0 0;
}

.page-about .about-plate__item {
  position: relative;
  border: 1px solid var(--line);
  border-radius: 2px;
  background: var(--parchment);
  padding: 16px 18px;
}

.page-about .about-plate__item::after {
  content: "";
  position: absolute;
  inset: 5px;
  border: 1px solid rgba(192, 138, 46, .38);
  pointer-events: none;
}

.page-about .about-plate__key {
  position: relative;
  display: block;
  margin-bottom: 7px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: .2em;
  color: var(--ink-soft);
}

.page-about .about-plate__val {
  position: relative;
  display: block;
  font-family: var(--font-mono);
  font-size: 16px;
  line-height: 1.5;
  letter-spacing: .02em;
  color: var(--teal-900);
  word-break: break-all;
}

/* ---------- 指路 ---------- */
.page-about .about-paths {
  margin-top: 46px;
  padding-top: 24px;
  border-top: 2px solid var(--teal-900);
}

.page-about .about-paths__title {
  margin: 0;
  font-family: var(--font-serif);
  font-weight: 800;
  font-size: 20px;
  line-height: 1.4;
  letter-spacing: .04em;
  color: var(--teal-900);
}

.page-about .about-paths__list {
  list-style: none;
  margin: 18px 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: 1fr;
  gap: 10px;
}

.page-about .about-paths__link {
  display: block;
  border: 1px solid var(--line);
  background: var(--paper);
  padding: 14px 16px;
  text-decoration: none;
  transition: border-color .2s ease-out, background .2s ease-out, transform .2s ease-out;
}

.page-about .about-paths__link:hover,
.page-about .about-paths__link:focus-visible {
  border-color: var(--brass);
  background: var(--parchment);
  transform: translateX(3px);
}

.page-about .about-paths__name {
  display: block;
  margin-bottom: 4px;
  font-family: var(--font-serif);
  font-weight: 700;
  font-size: 17px;
  letter-spacing: .04em;
  color: var(--teal-900);
}

.page-about .about-paths__desc {
  display: block;
  font-size: 14px;
  line-height: 1.72;
  color: var(--ink-soft);
}

/* ---------- 桌面端 ---------- */
@media (min-width: 768px) {
  .page-about .about-hero__title {
    font-size: 50px;
  }

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

  .page-about .about-head__title {
    font-size: 30px;
  }

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

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

  .page-about .about-stats {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

@media (min-width: 900px) {
  .page-about .about-shell {
    display: grid;
    grid-template-columns: var(--about-index-w) minmax(0, 1fr);
    gap: var(--about-gap);
    align-items: start;
  }

  .page-about .about-index {
    position: sticky;
    top: 132px;
    align-self: start;
    flex-direction: column;
    gap: 6px;
    overflow: visible;
    margin-bottom: 0;
    padding: 0 0 0 10px;
    border-bottom: 0;
    border-left: 1px solid var(--line);
  }

  .page-about .about-index__link {
    writing-mode: vertical-rl;
    padding: 13px 3px;
    border: 0;
    border-radius: 0;
    background: transparent;
    letter-spacing: .18em;
  }

  .page-about .about-index__link:hover,
  .page-about .about-index__link:focus-visible {
    color: var(--brass);
    background: transparent;
  }

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

  .page-about .about-section--parchment {
    padding: 34px 30px;
  }

  .page-about .about-section--dark {
    padding: 40px 36px;
  }

  .page-about .about-head__title {
    font-size: 32px;
  }

  .page-about .about-crew {
    flex-direction: row;
    align-items: stretch;
  }

  .page-about .about-crew__item:nth-child(1) {
    flex: 1.35 1 0;
  }

  .page-about .about-crew__item:nth-child(2) {
    flex: 1.5 1 0;
  }

  .page-about .about-crew__item:nth-child(3) {
    flex: 1.1 1 0;
  }

  .page-about .about-crew__item:nth-child(4) {
    flex: 1 1 0;
  }
}

@media (min-width: 1180px) {
  .page-about .about-hero__title {
    font-size: 62px;
    max-width: 13em;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-index__link,
  .page-about .about-crew__item,
  .page-about .about-paths__link,
  .page-about .about-stage .kit-fold__marker,
  .page-about .about-stage .kit-fold__head {
    transition: none;
  }

  .page-about .about-crew__item:hover,
  .page-about .about-crew__item:focus-within {
    transform: none;
  }

  .page-about .about-paths__link:hover,
  .page-about .about-paths__link:focus-visible {
    transform: none;
  }
}