.page-about {
  --about-rail-w: 220px;
  --about-block-pad: clamp(40px, 5vw, 64px);
  background-color: var(--cream-paper);
  color: var(--warm-black);
  font-family: var(--font-body);
  overflow-x: hidden;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  padding: var(--space-6) 0 var(--space-6);
  border-bottom: 1px solid var(--warm-grey);
  background-color: var(--cream-paper);
  background-image:
    repeating-linear-gradient(0deg, rgba(36, 30, 26, .035) 0 1px, transparent 1px 32px),
    repeating-linear-gradient(90deg, rgba(36, 30, 26, .035) 0 1px, transparent 1px 32px);
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--copper) 0%, var(--copper-light) 34%, var(--warm-grey) 34%, var(--warm-grey) 100%);
}

.page-about .about-hero__inner {
  position: relative;
}

.page-about .about-hero .breadcrumbs {
  margin-bottom: var(--space-4);
  font-family: var(--font-label);
  font-size: 12px;
  letter-spacing: .12em;
  color: var(--slate-grey);
}

.page-about .about-hero .breadcrumbs ol {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 0;
  padding: 0;
}

.page-about .about-hero .breadcrumbs li + li::before {
  content: "/";
  margin-right: 8px;
  color: var(--warm-grey);
}

.page-about .about-hero .breadcrumbs a {
  color: var(--indigo-mid);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: border-color 160ms ease;
}

.page-about .about-hero .breadcrumbs a:hover {
  border-bottom-color: var(--copper);
}

.page-about .about-hero__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--space-5);
  align-items: center;
}

.page-about .about-hero__eyebrow {
  display: inline-block;
  margin: 0 0 var(--space-2);
  padding: 5px 12px;
  border: 1px solid var(--copper);
  border-radius: var(--radius-card);
  background: rgba(183, 137, 63, .08);
  color: var(--copper);
  font-size: 12px;
  letter-spacing: .16em;
}

.page-about .about-hero__title {
  margin: 0 0 var(--space-3);
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(30px, 5.2vw, 58px);
  line-height: 1.14;
  letter-spacing: -.02em;
  color: var(--ink-indigo);
}

.page-about .about-hero__lede {
  margin: 0 0 var(--space-4);
  max-width: 46ch;
  font-size: 17px;
  line-height: 1.85;
  color: var(--warm-black);
}

.page-about .about-hero__facts {
  list-style: none;
  margin: 0 0 var(--space-4);
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--warm-grey);
  border: 1px solid var(--warm-grey);
}

.page-about .about-hero__facts li {
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding: 14px 16px;
  background: var(--porcelain);
}

.page-about .about-hero__num {
  font-size: 18px;
  font-weight: 600;
  color: var(--ink-indigo);
}

.page-about .about-hero__facts .label {
  font-size: 11px;
  letter-spacing: .1em;
  color: var(--slate-grey);
}

.page-about .about-hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
}

.page-about .about-hero__figure {
  position: relative;
  margin: 0;
  padding: 12px;
  background: var(--porcelain);
  border: 1px solid var(--warm-grey);
  border-radius: var(--radius-card);
  box-shadow: var(--shadow-paper);
}

.page-about .about-hero__figure::before {
  content: "";
  position: absolute;
  inset: 10px -6px -6px 10px;
  border: 1px solid var(--warm-grey);
  border-radius: var(--radius-card);
  z-index: -1;
}

.page-about .about-hero__figure img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  border-radius: 4px;
}

.page-about .about-hero__figure .media-frame__caption {
  display: block;
  margin-top: 10px;
  padding-top: 10px;
  border-top: 1px solid var(--warm-grey);
  font-family: var(--font-label);
  font-size: 12px;
  line-height: 1.6;
  color: var(--slate-grey);
}

/* ---------- 主体骨架 ---------- */
.page-about .about-shell {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 0;
  padding-top: var(--space-5);
  padding-bottom: var(--space-6);
}

.page-about .about-rail {
  margin-bottom: var(--space-4);
}

.page-about .about-rail__title {
  margin: 0 0 var(--space-2);
  font-size: 11px;
  letter-spacing: .18em;
  color: var(--slate-grey);
}

.page-about .about-rail__list {
  list-style: none;
  display: flex;
  gap: 8px;
  margin: 0;
  padding: 0 0 10px;
  overflow-x: auto;
  border-bottom: 1px solid var(--warm-grey);
  -webkit-overflow-scrolling: touch;
}

.page-about .about-rail__list::-webkit-scrollbar {
  height: 3px;
}

.page-about .about-rail__list::-webkit-scrollbar-thumb {
  background: var(--copper);
}

.page-about .about-rail__link {
  display: flex;
  align-items: baseline;
  gap: 8px;
  padding: 8px 12px;
  white-space: nowrap;
  border: 1px solid var(--warm-grey);
  border-radius: var(--radius-pill);
  text-decoration: none;
  color: var(--warm-black);
  font-family: var(--font-label);
  font-size: 13px;
  transition: border-color 160ms ease, color 160ms ease;
}

.page-about .about-rail__link:hover,
.page-about .about-rail__link.is-active {
  border-color: var(--copper);
  color: var(--ink-indigo);
}

.page-about .about-rail__num {
  font-size: 11px;
  color: var(--copper);
}

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

/* ---------- 内容块 ---------- */
.page-about .about-block {
  position: relative;
  padding: var(--about-block-pad) 0;
  border-top: 1px solid var(--warm-grey);
  scroll-margin-top: 104px;
}

.page-about .about-block:first-child {
  border-top: 0;
  padding-top: 0;
}

.page-about .about-block__index {
  display: inline-block;
  padding: 4px 10px;
  border: 1px solid var(--copper);
  border-radius: var(--radius-card);
  background: rgba(183, 137, 63, .07);
  font-size: 12px;
  letter-spacing: .16em;
  color: var(--copper);
}

.page-about .about-block__title {
  margin: var(--space-2) 0 12px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(23px, 3vw, 34px);
  line-height: 1.25;
  letter-spacing: -.01em;
  color: var(--ink-indigo);
}

.page-about .about-block__lede {
  margin: 0;
  max-width: 52ch;
  font-size: 16px;
  line-height: 1.85;
  color: var(--slate-grey);
}

.page-about .about-block__body {
  margin-top: var(--space-3);
}

.page-about .about-block__body p,
.page-about .about-review__steps p,
.page-about .about-roles__text,
.page-about .about-supply__cell p,
.page-about .about-scale__item p {
  max-width: 62ch;
  margin: 0 0 var(--space-2);
  font-size: 17px;
  line-height: 1.85;
  color: var(--warm-black);
}

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

.page-about .about-block__foot {
  margin: var(--space-3) 0 0;
  padding-top: var(--space-2);
  border-top: 1px solid var(--warm-grey);
  font-size: 15px;
  line-height: 1.8;
  color: var(--slate-grey);
}

.page-about .about-block__foot a {
  color: var(--indigo-mid);
  text-decoration: none;
  border-bottom: 1px solid var(--copper);
}

/* ---------- 编号拆解 ---------- */
.page-about .code-map {
  margin-top: var(--space-4);
  padding: var(--space-3);
  border: 1px solid var(--warm-grey);
  border-radius: var(--radius-card);
  background: var(--porcelain);
  box-shadow: var(--shadow-paper);
}

.page-about .code-map__sample {
  margin: 0 0 var(--space-3);
  padding-bottom: var(--space-2);
  border-bottom: 1px solid var(--warm-grey);
  font-size: clamp(20px, 3.4vw, 30px);
  font-weight: 600;
  letter-spacing: .22em;
  color: var(--ink-indigo);
}

.page-about .code-map__parts {
  list-style: none;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--space-2);
  margin: 0;
  padding: 0;
}

.page-about .code-map__part {
  position: relative;
  padding: var(--space-2) var(--space-3);
  border: 1px solid var(--warm-grey);
  border-left: 3px solid var(--copper);
  border-radius: 0 var(--radius-card) var(--radius-card) 0;
  background: var(--cream-paper);
  transition: transform 160ms ease, border-color 160ms ease, box-shadow 160ms ease;
}

.page-about .code-map__part--a {
  border-left-color: var(--ink-indigo);
}

.page-about .code-map__part--b {
  border-left-color: var(--indigo-mid);
}

.page-about .code-map__part--c {
  border-left-color: var(--copper);
}

.page-about .code-map__part--d {
  border-left-color: var(--slate-grey);
}

.page-about .code-map__part:hover {
  transform: translate(2px, -2px);
  border-color: var(--copper);
  box-shadow: var(--shadow-paper);
}

.page-about .code-map__glyph {
  display: block;
  font-size: 22px;
  font-weight: 600;
  letter-spacing: .18em;
  color: var(--ink-indigo);
}

.page-about .code-map__role {
  display: block;
  margin: 4px 0 8px;
  font-size: 11px;
  letter-spacing: .16em;
  color: var(--copper);
}

.page-about .code-map__desc {
  margin: 0;
  font-size: 14px;
  line-height: 1.75;
  color: var(--warm-black);
}

/* ---------- 沿革时间轴 ---------- */
.page-about .about-timeline {
  list-style: none;
  display: flex;
  gap: var(--space-3);
  margin: var(--space-4) 0 0;
  padding: var(--space-3) 0 14px;
  overflow-x: auto;
  scroll-snap-type: x proximity;
  border-top: 1px solid var(--copper);
  -webkit-overflow-scrolling: touch;
}

.page-about .about-timeline::-webkit-scrollbar {
  height: 3px;
}

.page-about .about-timeline::-webkit-scrollbar-thumb {
  background: var(--copper);
}

.page-about .about-timeline__item {
  flex: 0 0 236px;
  scroll-snap-align: start;
  padding-left: var(--space-2);
  border-left: 1px solid var(--warm-grey);
}

.page-about .about-timeline__item::before {
  content: "";
  display: block;
  width: 9px;
  height: 9px;
  margin: 0 0 12px calc(-1 * var(--space-2) - 5px);
  border: 1px solid var(--copper);
  border-radius: 50%;
  background: var(--cream-paper);
}

.page-about .about-timeline__year {
  display: block;
  font-size: 15px;
  font-weight: 600;
  letter-spacing: .16em;
  color: var(--copper);
}

.page-about .about-timeline__title {
  margin: 6px 0 8px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 16px;
  line-height: 1.4;
  color: var(--ink-indigo);
}

.page-about .about-timeline__text {
  margin: 0;
  font-size: 14px;
  line-height: 1.8;
  color: var(--warm-black);
}

/* ---------- 季度核对机制 ---------- */
.page-about .about-review {
  isolation: isolate;
  overflow: hidden;
  border-top: 1px solid var(--warm-grey);
}

.page-about .about-review__bg {
  position: absolute;
  inset: 0;
  z-index: -1;
  opacity: .12;
}

.page-about .about-review__bg img {
  display: block;
  width: 100%;
  height: 100%;
  max-width: 100%;
  object-fit: cover;
}

.page-about .about-review__inner {
  position: relative;
}

.page-about .about-review__steps {
  list-style: none;
  margin: var(--space-4) 0 0;
  padding: 0;
  display: grid;
  gap: 0;
}

.page-about .about-review__steps li {
  display: grid;
  grid-template-columns: 48px minmax(0, 1fr);
  gap: var(--space-2);
  padding: var(--space-3) 0;
  border-top: 1px solid var(--warm-grey);
}

.page-about .about-review__steps li:first-child {
  border-top: 1px solid var(--copper);
}

.page-about .about-review__steps h3 {
  margin: 0 0 6px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 17px;
  color: var(--ink-indigo);
}

.page-about .about-review__step {
  font-size: 14px;
  font-weight: 600;
  letter-spacing: .14em;
  color: var(--copper);
}

.page-about .about-review .note {
  margin-top: var(--space-3);
  padding: var(--space-3);
  border: 1px solid var(--copper);
  border-left: 3px solid var(--vermilion);
  border-radius: 0 var(--radius-card) var(--radius-card) 0;
  background: rgba(192, 57, 43, .05);
  font-size: 15px;
  line-height: 1.85;
  color: var(--warm-black);
}

/* ---------- 协作分工 ---------- */
.page-about .about-roles {
  list-style: none;
  margin: var(--space-4) 0 0;
  padding: 0;
}

.page-about .about-roles li {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 6px;
  padding: var(--space-3) 0;
  border-top: 1px solid var(--warm-grey);
}

.page-about .about-roles li:first-child {
  border-top: 2px solid var(--ink-indigo);
}

.page-about .about-roles__num {
  font-size: 12px;
  letter-spacing: .16em;
  color: var(--copper);
}

.page-about .about-roles__name {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 17px;
  color: var(--ink-indigo);
}

.page-about .about-roles__text {
  margin: 0;
  font-size: 15px;
  line-height: 1.8;
  color: var(--warm-black);
}

/* ---------- 定制范围与原料 ---------- */
.page-about .about-supply__figure {
  position: relative;
  margin: var(--space-4) 0 0;
  border: 1px solid var(--warm-grey);
  border-radius: var(--radius-card);
  overflow: hidden;
  background: var(--porcelain);
}

.page-about .about-supply__figure img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  aspect-ratio: 3 / 2;
  object-fit: cover;
}

.page-about .about-supply__figure .media-frame__caption {
  display: block;
  padding: 12px 16px;
  border-top: 1px solid var(--warm-grey);
  font-family: var(--font-label);
  font-size: 12px;
  line-height: 1.6;
  color: var(--slate-grey);
}

.page-about .about-supply__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--space-3);
  margin-top: var(--space-4);
}

.page-about .about-supply__cell {
  padding-left: var(--space-3);
  border-left: 1px solid var(--copper);
}

.page-about .about-supply__code {
  display: block;
  font-size: 12px;
  letter-spacing: .18em;
  color: var(--copper);
}

.page-about .about-supply__cell h3 {
  margin: 8px 0 8px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 17px;
  color: var(--ink-indigo);
}

.page-about .about-supply__cell p {
  margin: 0;
  font-size: 15px;
  line-height: 1.8;
}

.page-about .about-supply__scale {
  margin-top: var(--space-5);
  padding-top: var(--space-3);
  border-top: 1px solid var(--warm-grey);
}

.page-about .about-supply__scale-title {
  margin: 0 0 var(--space-3);
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 18px;
  color: var(--ink-indigo);
}

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

.page-about .about-scale__item {
  display: grid;
  grid-template-columns: 92px minmax(0, 1fr);
  gap: 4px var(--space-3);
  padding: var(--space-3) 0;
  border-top: 1px solid var(--warm-grey);
}

.page-about .about-scale__range {
  font-size: 15px;
  font-weight: 600;
  letter-spacing: .12em;
  color: var(--ink-indigo);
}

.page-about .about-scale__name {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 16px;
  color: var(--copper);
}

.page-about .about-scale__item p {
  grid-column: 1 / -1;
  margin: 0;
  font-size: 15px;
  line-height: 1.8;
}

/* ---------- 后续入口 ---------- */
.page-about .about-next {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  margin-top: var(--space-5);
  border: 1px solid var(--warm-grey);
  background: var(--warm-grey);
}

.page-about .about-next__item {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 4px;
  padding: var(--space-3);
  background: var(--porcelain);
  text-decoration: none;
  transition: background-color 160ms ease;
}

.page-about .about-next__item:hover {
  background: var(--indigo-mist);
}

.page-about .about-next__path {
  font-size: 12px;
  letter-spacing: .16em;
  color: var(--copper);
}

.page-about .about-next__title {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 17px;
  color: var(--ink-indigo);
}

.page-about .about-next__desc {
  font-family: var(--font-body);
  font-size: 14px;
  line-height: 1.7;
  color: var(--slate-grey);
}

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

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

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

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

@media (min-width: 900px) {
  .page-about .about-hero {
    padding: var(--space-7) 0 var(--space-6);
  }

  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 4fr);
    gap: var(--space-6);
    align-items: center;
  }

  .page-about .about-shell {
    grid-template-columns: var(--about-rail-w) minmax(0, 1fr);
    gap: var(--space-6);
    padding-top: var(--space-6);
  }

  .page-about .about-rail {
    position: sticky;
    top: 104px;
    margin-bottom: 0;
  }

  .page-about .about-rail__list {
    flex-direction: column;
    gap: var(--space-3);
    overflow: visible;
    padding: 0 0 0 var(--space-4);
    border-bottom: 0;
    border-left: 1px solid var(--copper);
  }

  .page-about .about-rail__link {
    padding: 0;
    border: 0;
    border-radius: 0;
    background: none;
    white-space: normal;
    align-items: baseline;
  }

  .page-about .about-rail__link.is-active .about-rail__text {
    color: var(--ink-indigo);
    font-weight: 700;
  }

  .page-about .about-rail__link.is-active .about-rail__num {
    color: var(--vermilion);
  }

  .page-about .about-block:first-child {
    padding-top: 0;
  }

  .page-about .about-roles li {
    grid-template-columns: 76px 180px minmax(0, 1fr);
    gap: var(--space-3);
    align-items: baseline;
  }

  .page-about .about-scale__item {
    grid-template-columns: 96px 180px minmax(0, 1fr);
    align-items: baseline;
  }

  .page-about .about-scale__item p {
    grid-column: 3;
  }

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

@media (max-width: 899px) {
  .page-about .about-hero__figure::before {
    display: none;
  }

  .page-about .about-timeline__item {
    flex: 0 0 200px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .code-map__part,
  .page-about .about-rail__link,
  .page-about .about-next__item {
    transition: none;
  }

  .page-about .code-map__part:hover {
    transform: none;
  }
}