.page-about {
  --about-rail-w: 208px;
  --about-cream-text: #4A382B;
  background: var(--ink-900);
  color: var(--cold);
  padding-top: calc(var(--header-h) + 24px);
  overflow-x: clip;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  padding: 24px 0 56px;
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(237, 242, 238, .05) 1px, transparent 1px),
    linear-gradient(90deg, rgba(237, 242, 238, .05) 1px, transparent 1px);
  background-size: 24px 24px;
  -webkit-mask-image: linear-gradient(180deg, rgba(0, 0, 0, .95), transparent 88%);
  mask-image: linear-gradient(180deg, rgba(0, 0, 0, .95), transparent 88%);
  pointer-events: none;
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  right: -12%;
  top: 8%;
  width: 46vw;
  height: 46vw;
  max-width: 560px;
  max-height: 560px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(255, 107, 26, .16), transparent 68%);
  pointer-events: none;
}

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

.page-about .about-hero__title {
  margin: 18px 0 0;
  max-width: 18ch;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(2.25rem, 7vw, 5rem);
  line-height: 1;
  letter-spacing: -.02em;
  color: var(--cold);
}

.page-about .about-hero__lede {
  margin: 24px 0 0;
  max-width: 40em;
  color: var(--text-70);
}

.page-about .about-stats {
  list-style: none;
  margin: 40px 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--hair);
  border: 1px solid var(--hair);
  border-radius: var(--radius);
  overflow: hidden;
}

@media (min-width: 760px) {
  .page-about .about-stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

.page-about .about-stat {
  background: var(--green-900);
  padding: 20px 18px;
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.page-about .about-stat__value {
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: clamp(1.5rem, 4vw, 2.25rem);
  line-height: 1;
  color: var(--signal);
}

.page-about .about-stat__label {
  font-size: .75rem;
  font-weight: 500;
  letter-spacing: .08em;
  color: var(--text-55);
}

/* ---------- 主体两栏 ---------- */
.page-about .about-body {
  display: grid;
  gap: 28px;
  padding-bottom: 88px;
}

@media (min-width: 1040px) {
  .page-about .about-body {
    grid-template-columns: var(--about-rail-w) minmax(0, 1fr);
    gap: 56px;
    padding-bottom: 132px;
  }
}

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

/* ---------- 左侧历程刻度 ---------- */
.page-about .about-rail {
  border-top: 1px solid var(--hair);
  padding-top: 14px;
}

.page-about .about-rail__label {
  margin: 0 0 10px;
  font-family: var(--font-mono);
  font-size: .68rem;
  font-weight: 500;
  letter-spacing: .18em;
  color: var(--steel);
}

.page-about .about-rail__list {
  list-style: none;
  margin: 0;
  padding: 0 0 6px;
  display: flex;
  gap: 10px;
  overflow-x: auto;
  scrollbar-width: thin;
  -webkit-overflow-scrolling: touch;
}

.page-about .about-rail__item {
  flex: 0 0 auto;
}

.page-about .about-rail__link {
  display: flex;
  align-items: baseline;
  gap: 8px;
  position: relative;
  padding: 8px 14px;
  border: 1px solid var(--hair);
  border-radius: var(--radius-pill);
  color: var(--text-55);
  text-decoration: none;
  white-space: nowrap;
  transition: color .24s var(--ease), border-color .24s var(--ease), background-color .24s var(--ease);
}

.page-about .about-rail__link:hover {
  color: var(--cold);
  border-color: var(--glass-line);
}

.page-about .about-rail__link[aria-current="true"] {
  color: var(--cold);
  border-color: var(--signal);
  background: rgba(255, 107, 26, .1);
}

.page-about .about-rail__year {
  font-family: var(--font-mono);
  font-size: .85rem;
  font-weight: 700;
  letter-spacing: .04em;
}

.page-about .about-rail__name {
  font-size: .75rem;
  letter-spacing: .06em;
  opacity: .8;
}

@media (min-width: 1040px) {
  .page-about .about-rail {
    position: sticky;
    top: calc(var(--header-h-compact) + 32px);
    align-self: start;
    border-top: 0;
    padding-top: 0;
    border-left: 1px solid var(--hair);
    padding-left: 22px;
  }

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

  .page-about .about-rail__list {
    display: block;
    overflow: visible;
    padding: 0;
  }

  .page-about .about-rail__item {
    position: relative;
    padding-bottom: 30px;
  }

  .page-about .about-rail__item::after {
    content: "";
    position: absolute;
    left: 0;
    top: 20px;
    bottom: 6px;
    width: 1px;
    background: var(--hair);
  }

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

  .page-about .about-rail__item:last-child::after {
    display: none;
  }

  .page-about .about-rail__link {
    display: block;
    padding: 0 0 0 22px;
    border: 0;
    border-radius: 0;
    background: none;
    white-space: normal;
  }

  .page-about .about-rail__link::before {
    content: "";
    position: absolute;
    left: 0;
    top: 7px;
    width: 9px;
    height: 9px;
    border-radius: 50%;
    margin-left: -4px;
    background: var(--steel);
    transition: background-color .24s var(--ease), transform .24s var(--ease), box-shadow .24s var(--ease);
  }

  .page-about .about-rail__link:hover {
    border-color: transparent;
    background: none;
  }

  .page-about .about-rail__link[aria-current="true"] {
    background: none;
    border-color: transparent;
  }

  .page-about .about-rail__link[aria-current="true"]::before {
    background: var(--signal);
    transform: scale(1.25);
    box-shadow: 0 0 0 4px rgba(255, 107, 26, .18);
  }

  .page-about .about-rail__year {
    display: block;
    font-size: 1rem;
  }

  .page-about .about-rail__name {
    display: block;
    margin-top: 4px;
  }
}

/* ---------- 章节 ---------- */
.page-about .about-section {
  padding-block: clamp(44px, 8vw, 72px);
  border-top: 1px solid var(--hair);
}

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

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

.page-about .chapter__title {
  font-size: clamp(1.4rem, 3.4vw, 2.125rem);
  line-height: 1.28;
  color: var(--cold);
}

.page-about .about-p {
  margin: 0 0 18px;
  max-width: 40em;
  font-size: 1.0625rem;
  line-height: 1.75;
  color: var(--text-70);
}

.page-about .about-p--tight {
  margin-bottom: 0;
}

.page-about .about-p--after {
  margin-top: 24px;
  margin-bottom: 0;
}

.page-about .about-p a {
  color: var(--signal-soft);
  text-decoration: none;
  border-bottom: 1px solid rgba(255, 107, 26, .4);
  transition: color .2s var(--ease), border-color .2s var(--ease);
}

.page-about .about-p a:hover {
  color: var(--signal);
  border-color: var(--signal);
}

/* ---------- 数据条 ---------- */
.page-about .about-mark {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 8px 20px;
  margin: 28px 0 0;
  padding: 18px 22px;
  background: var(--glass);
  border: 1px solid var(--glass-line);
  border-left: 3px solid var(--signal);
  border-radius: var(--radius-sm);
}

.page-about .about-mark__num {
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 1.125rem;
  letter-spacing: .02em;
  color: var(--signal);
}

.page-about .about-mark__text {
  flex: 1 1 240px;
  font-size: .95rem;
  line-height: 1.65;
  color: var(--text-70);
}

/* ---------- 奶油底章节 ---------- */
.page-about .about-section--cream {
  background: var(--cream);
  color: var(--brown);
  border-top: 0;
  border-radius: var(--radius);
  padding: clamp(28px, 5vw, 44px) clamp(20px, 4vw, 40px);
  margin-block: clamp(44px, 8vw, 72px);
}

.page-about .about-section--cream .chapter__title {
  color: var(--brown);
}

.page-about .about-section--cream .chapter__num {
  color: var(--signal);
}

.page-about .about-section--cream .about-p {
  color: var(--about-cream-text);
}

.page-about .about-section--cream .about-p a {
  color: var(--brown);
  border-bottom-color: rgba(43, 28, 18, .35);
}

.page-about .source-list {
  list-style: none;
  margin: 26px 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: 1fr;
  gap: 1px;
  background: rgba(43, 28, 18, .16);
  border-radius: var(--radius-sm);
  overflow: hidden;
}

@media (min-width: 720px) {
  .page-about .source-list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

.page-about .source-item {
  background: var(--cream);
  padding: 20px 22px;
}

.page-about .source-item__tag {
  display: inline-block;
  margin-bottom: 8px;
  padding-bottom: 6px;
  border-bottom: 2px solid var(--turf);
  font-family: var(--font-mono);
  font-size: .8rem;
  font-weight: 700;
  letter-spacing: .06em;
  color: var(--brown);
}

.page-about .source-item__text {
  margin: 0;
  font-size: .95rem;
  line-height: 1.7;
  color: var(--about-cream-text);
}

/* ---------- 图片 ---------- */
.page-about .about-figure {
  margin: 40px 0 0;
}

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

.page-about .about-figure--side {
  max-width: 620px;
}

.page-about .about-figure--square {
  max-width: 520px;
  margin-inline: auto;
}

/* ---------- 四步流程 ---------- */
.page-about .about-flow {
  list-style: none;
  margin: 32px 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: 1fr;
  gap: 16px;
  counter-reset: flow;
}

@media (min-width: 880px) {
  .page-about .about-flow {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 24px;
  }
}

.page-about .flow-step {
  position: relative;
  padding: 20px 18px;
  background: var(--green-900);
  border: 1px solid var(--hair);
  border-radius: var(--radius);
  transition: border-color .24s var(--ease), transform .24s var(--ease);
}

.page-about .flow-step::before {
  content: "";
  position: absolute;
  left: 18px;
  right: 18px;
  top: 0;
  height: 2px;
  background: var(--turf);
  border-radius: 0 0 2px 2px;
}

.page-about .flow-step:hover,
.page-about .flow-step:focus-within {
  border-color: var(--glass-line);
  transform: translateY(-2px);
}

@media (min-width: 880px) {
  .page-about .flow-step + .flow-step::after {
    content: "";
    position: absolute;
    left: -24px;
    top: 50%;
    width: 24px;
    height: 1px;
    background: var(--turf);
  }
}

.page-about .flow-step__num {
  display: block;
  font-family: var(--font-mono);
  font-size: .78rem;
  font-weight: 700;
  letter-spacing: .12em;
  color: var(--turf);
  margin-bottom: 10px;
}

.page-about .flow-step__title {
  margin: 0 0 8px;
  font-size: 1.125rem;
  font-weight: 700;
  color: var(--cold);
}

.page-about .flow-step__text {
  margin: 0;
  font-size: .9rem;
  line-height: 1.65;
  color: var(--text-70);
}

.page-about .flow-step__detail {
  margin: 10px 0 0;
  font-size: .82rem;
  line-height: 1.6;
  color: var(--text-55);
  max-height: none;
  opacity: 1;
}

@media (min-width: 880px) {
  .page-about .flow-step__detail {
    max-height: 0;
    margin-top: 0;
    overflow: hidden;
    opacity: 0;
    transition: max-height .3s var(--ease), opacity .3s var(--ease), margin-top .3s var(--ease);
  }

  .page-about .flow-step:hover .flow-step__detail,
  .page-about .flow-step:focus-within .flow-step__detail {
    max-height: 200px;
    margin-top: 10px;
    opacity: 1;
  }
}

@media (min-width: 880px) and (prefers-reduced-motion: reduce) {
  .page-about .flow-step__detail {
    max-height: none;
    margin-top: 10px;
    opacity: 1;
    transition: none;
  }
}

.page-about .about-flow__note {
  margin: 32px 0 0;
  padding: 20px 22px;
  border-left: 3px solid var(--turf);
  background: rgba(62, 142, 90, .08);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
}

/* ---------- 团队 ---------- */
.page-about .team-grid {
  list-style: none;
  margin: 28px 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: 1fr;
  gap: 16px;
}

@media (min-width: 720px) {
  .page-about .team-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

.page-about .team-card {
  position: relative;
  padding: 24px 22px;
  background: var(--green-900);
  border: 1px solid var(--hair);
  border-radius: var(--radius);
}

.page-about .team-card__num {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 30px;
  height: 30px;
  margin-bottom: 14px;
  border-radius: 50%;
  border: 1px solid var(--glass-line);
  font-family: var(--font-mono);
  font-size: .8rem;
  font-weight: 700;
  color: var(--turf);
}

.page-about .team-card__title {
  margin: 0 0 8px;
  font-size: 1.0625rem;
  font-weight: 700;
  color: var(--cold);
}

.page-about .team-card__text {
  margin: 0;
  font-size: .92rem;
  line-height: 1.7;
  color: var(--text-70);
}

/* ---------- 合作生态 ---------- */
.page-about .eco-list {
  list-style: none;
  margin: 28px 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: 1fr;
  gap: 0;
  border-top: 1px solid var(--hair);
}

.page-about .eco-item {
  padding: 22px 0 22px 20px;
  border-bottom: 1px solid var(--hair);
  border-left: 2px solid transparent;
  transition: border-left-color .24s var(--ease), background-color .24s var(--ease);
}

.page-about .eco-item:hover {
  border-left-color: var(--signal);
  background: rgba(237, 242, 238, .03);
}

.page-about .eco-item__title {
  margin: 0 0 8px;
  font-size: 1.0625rem;
  font-weight: 700;
  color: var(--cold);
}

.page-about .eco-item__text {
  margin: 0;
  max-width: 44em;
  font-size: .95rem;
  line-height: 1.72;
  color: var(--text-70);
}

.page-about .eco-item__text a {
  color: var(--signal-soft);
  text-decoration: none;
  border-bottom: 1px solid rgba(255, 107, 26, .4);
}

.page-about .eco-item__text a:hover {
  color: var(--signal);
  border-color: var(--signal);
}

/* ---------- 收束 ---------- */
.page-about .about-cta {
  margin-top: 36px;
  padding: 28px 24px;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 18px 28px;
  background: var(--green-900);
  border: 1px solid var(--glass-line);
  border-radius: var(--radius);
}

.page-about .about-cta__text {
  flex: 1 1 260px;
  margin: 0;
  font-size: 1rem;
  line-height: 1.7;
  color: var(--cold);
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-rail__link,
  .page-about .flow-step,
  .page-about .eco-item {
    transition: none;
  }
}