.page-about {
  --about-rail: 240px;
  --about-line: 1px solid rgba(89, 98, 111, .26);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  padding-bottom: clamp(32px, 5vw, 72px);
  background:
    linear-gradient(180deg, rgba(22, 105, 127, .10), rgba(220, 233, 239, 0) 72%),
    var(--c-snow);
  border-bottom: var(--about-line);
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  right: -12%;
  bottom: -46%;
  width: min(720px, 90%);
  height: 420px;
  background: radial-gradient(120% 100% at 50% 100%, rgba(62, 146, 172, .26), transparent 68%);
  pointer-events: none;
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  width: 100%;
  height: 6px;
  background: linear-gradient(90deg, var(--c-primary) 0 46%, var(--c-gold) 46% 62%, var(--c-deep) 62% 100%);
}

.page-about .about-hero__grid {
  position: relative;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(26px, 4vw, 52px);
  padding-top: clamp(34px, 6vw, 82px);
}

@media (min-width: 940px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    align-items: end;
    gap: clamp(32px, 5vw, 72px);
  }
}

.page-about .about-hero .breadcrumb {
  font-size: 12.5px;
  color: var(--c-stone);
  margin-bottom: 18px;
}

.page-about .about-hero .breadcrumb a {
  color: var(--c-stone);
  text-decoration: none;
}

.page-about .about-hero .breadcrumb a:hover {
  color: var(--c-primary);
  text-decoration: underline;
  text-underline-offset: 3px;
}

.page-about .about-hero h1 {
  margin: 12px 0 0;
  font-size: clamp(32px, 5.6vw, 68px);
  font-weight: 300;
  line-height: 1.1;
  letter-spacing: -.022em;
  color: var(--c-ink);
  max-width: 20ch;
}

.page-about .about-hero .lede {
  margin-top: clamp(18px, 2.4vw, 26px);
  max-width: 42em;
  font-size: 17px;
  line-height: 1.8;
  color: var(--c-stone);
}

.page-about .about-hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: clamp(22px, 3vw, 32px);
}

/* 分组卡 */
.page-about .about-hero__roster {
  position: relative;
  background: var(--c-deep);
  color: var(--c-snow);
  border: 2px solid var(--c-deep);
  box-shadow: var(--shadow-hard);
  padding: clamp(20px, 3vw, 28px);
}

.page-about .about-hero__roster-title {
  margin: 0;
  font-size: 12px;
  letter-spacing: .18em;
  color: var(--c-gold-lt);
}

.page-about .about-roster-list {
  list-style: none;
  margin: 16px 0 0;
  padding: 0;
  display: grid;
  gap: 3px;
}

.page-about .about-roster-list li {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 11px 12px;
  background: rgba(251, 250, 247, .06);
  border-left: 3px solid var(--c-mid);
  transition: background-color .18s ease, border-color .18s ease, transform .18s ease;
}

.page-about .about-roster-list li:hover {
  background: rgba(223, 162, 43, .18);
  border-left-color: var(--c-gold);
  transform: translateX(3px);
}

.page-about .about-roster__num {
  font-size: 11.5px;
  letter-spacing: .14em;
  color: var(--c-gold-lt);
}

.page-about .about-roster__name {
  font-size: 15px;
  font-weight: 500;
}

.page-about .about-hero__roster-note {
  margin: 18px 0 0;
  font-size: 13.5px;
  line-height: 1.7;
  color: rgba(251, 250, 247, .72);
}

/* ---------- 主体网格 ---------- */
.page-about .about-body {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(28px, 4vw, 56px);
  padding-top: clamp(40px, 6vw, 84px);
  padding-bottom: clamp(48px, 8vw, 112px);
}

@media (min-width: 1024px) {
  .page-about .about-body {
    grid-template-columns: var(--about-rail) minmax(0, 1fr);
    gap: clamp(36px, 5vw, 80px);
    align-items: start;
  }
}

/* 左索引 */
.page-about .about-index {
  border-top: 2px solid var(--c-ink);
  padding-top: 16px;
}

@media (min-width: 1024px) {
  .page-about .about-index {
    position: sticky;
    top: calc(var(--header-h) + 28px);
  }
}

.page-about .about-index__title {
  margin: 0 0 14px;
  font-size: 11.5px;
  letter-spacing: .2em;
  color: var(--c-stone);
}

.page-about .about-index__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 2px;
}

.page-about .about-index__list a {
  display: flex;
  gap: 10px;
  align-items: baseline;
  padding: 9px 10px;
  font-size: 14px;
  line-height: 1.5;
  color: var(--c-stone);
  text-decoration: none;
  border-left: 2px solid transparent;
  transition: color .18s ease, background-color .18s ease, border-color .18s ease;
}

.page-about .about-index__list a .mono {
  font-size: 11.5px;
  letter-spacing: .12em;
  color: var(--c-mid);
}

.page-about .about-index__list a:hover {
  color: var(--c-primary);
  background: var(--c-mist);
  border-left-color: var(--c-gold);
}

.page-about .about-index__top {
  display: inline-block;
  margin-top: 18px;
  font-size: 11.5px;
  letter-spacing: .16em;
  color: var(--c-stone);
  text-decoration: none;
  border-bottom: 1px dashed var(--c-stone);
  padding-bottom: 2px;
}

.page-about .about-index__top:hover {
  color: var(--c-primary);
  border-bottom-color: var(--c-primary);
}

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

.page-about .about-section {
  padding-block: clamp(30px, 4.4vw, 58px);
  scroll-margin-top: calc(var(--header-h) + 24px);
}

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

.page-about .about-section + .about-section--dark,
.page-about .about-section--dark + .about-section {
  border-top: 0;
}

.page-about .about-section h2 {
  margin: 10px 0 0;
  font-size: clamp(25px, 3.4vw, 40px);
  font-weight: 400;
  line-height: 1.2;
  letter-spacing: -.016em;
  color: var(--c-ink);
  max-width: 24ch;
}

.page-about .about-section__lead {
  margin-top: 18px;
  max-width: 40em;
  font-size: 16.5px;
  line-height: 1.8;
  color: var(--c-stone);
}

.page-about .about-section__lead--on-dark {
  color: rgba(251, 250, 247, .78);
}

.page-about .about-inline-link {
  color: var(--c-primary);
  font-weight: 700;
  text-decoration: none;
  box-shadow: inset 0 -6px 0 var(--c-gold-lt);
}

.page-about .about-inline-link:hover {
  box-shadow: inset 0 -10px 0 var(--c-gold);
}

/* ---------- 谁在用它 ---------- */
.page-about .about-who {
  display: grid;
  gap: 22px;
  margin-top: clamp(28px, 4vw, 42px);
}

@media (min-width: 840px) {
  .page-about .about-who {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    align-items: start;
  }
  .page-about .about-who > *:nth-child(2) { margin-top: 46px; }
  .page-about .about-who > *:nth-child(3) { margin-top: 18px; }
}

.page-about .about-who__card {
  background: var(--c-snow);
  border: 2px solid var(--c-ink);
  border-top: 6px solid var(--c-primary);
  box-shadow: var(--shadow-hard);
  padding: 22px 20px 24px;
  transition: transform .2s ease, box-shadow .2s ease;
}

.page-about .about-who__card:nth-child(2) { border-top-color: var(--c-gold); }
.page-about .about-who__card:nth-child(3) { border-top-color: var(--c-indigo); }

.page-about .about-who__card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-float);
}

.page-about .about-who__tag {
  margin: 0;
  font-size: 11.5px;
  letter-spacing: .18em;
  color: var(--c-stone);
}

.page-about .about-who__card h3 {
  margin: 12px 0 0;
  font-size: 18px;
  font-weight: 600;
  line-height: 1.4;
  color: var(--c-ink);
}

.page-about .about-who__card p:last-child {
  margin: 12px 0 0;
  font-size: 15.5px;
  line-height: 1.8;
  color: var(--c-stone);
}

/* ---------- 四步流程 ---------- */
.page-about .about-flow__track {
  display: block;
  width: 100%;
  height: 34px;
  margin-top: clamp(28px, 4vw, 40px);
  color: var(--c-mid);
}

.page-about .about-flow {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 14px;
}

@media (min-width: 920px) {
  .page-about .about-flow {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 0;
  }
  .page-about .about-flow__step + .about-flow__step {
    margin-left: -2px;
  }
}

.page-about .about-flow__step {
  position: relative;
  background: var(--c-mist);
  border: 2px solid var(--c-primary);
  padding: 20px 18px 22px;
}

@media (min-width: 920px) {
  .page-about .about-flow__step::after {
    content: "";
    position: absolute;
    right: -11px;
    top: 50%;
    width: 18px;
    height: 2px;
    background: var(--c-gold);
    transform: translateY(-50%);
    z-index: 2;
  }
  .page-about .about-flow__step:last-child::after { display: none; }
}

.page-about .about-flow__num {
  display: inline-block;
  background: var(--c-gold);
  color: var(--c-ink);
  font-size: 11.5px;
  letter-spacing: .14em;
  padding: 3px 9px;
}

.page-about .about-flow__step h3 {
  margin: 14px 0 0;
  font-size: 17px;
  font-weight: 600;
  color: var(--c-deep);
}

.page-about .about-flow__step p {
  margin: 10px 0 0;
  font-size: 15px;
  line-height: 1.78;
  color: var(--c-ink);
}

.page-about .about-figure {
  margin: clamp(30px, 4vw, 46px) 0 0;
  border: 2px solid var(--c-ink);
  box-shadow: var(--shadow-hard);
  background: var(--c-snow);
  overflow: hidden;
}

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

/* ---------- 深色改版区 ---------- */
.page-about .about-section--dark {
  position: relative;
  margin-block: clamp(28px, 4vw, 48px);
  padding: clamp(26px, 4vw, 48px) clamp(20px, 3.4vw, 44px) clamp(30px, 4vw, 52px);
  background: var(--c-deep);
  color: var(--c-snow);
  border: 2px solid var(--c-deep);
  box-shadow: var(--shadow-hard);
}

.page-about .about-section--dark::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  width: 100%;
  height: 4px;
  background: linear-gradient(90deg, var(--c-gold) 0 30%, var(--c-mid) 30% 68%, var(--c-indigo) 68% 100%);
}

.page-about .about-section--dark h2 {
  color: var(--c-snow);
}

.page-about .about-section--dark .eyebrow {
  color: var(--c-gold-lt);
  border-left-color: var(--c-gold);
}

.page-about .about-timeline {
  margin-top: clamp(26px, 3.4vw, 38px);
  display: grid;
  gap: 12px;
}

.page-about .about-phase {
  border: 2px solid rgba(251, 250, 247, .24);
  background: rgba(251, 250, 247, .05);
  transition: border-color .2s ease, background-color .2s ease;
}

.page-about .about-phase[open] {
  border-color: var(--c-gold);
  background: rgba(223, 162, 43, .12);
}

.page-about .about-phase:hover {
  border-color: rgba(245, 215, 149, .7);
}

.page-about .about-phase__head {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 6px 16px;
  padding: 16px 18px;
  cursor: pointer;
  list-style: none;
}

.page-about .about-phase__head::-webkit-details-marker { display: none; }

.page-about .about-phase__head::after {
  content: "＋";
  margin-left: auto;
  font-size: 17px;
  line-height: 1;
  color: var(--c-gold);
  transition: transform .2s ease;
}

.page-about .about-phase[open] .about-phase__head::after {
  transform: rotate(45deg);
}

.page-about .about-phase__num {
  font-size: 11.5px;
  letter-spacing: .16em;
  color: var(--c-gold-lt);
}

.page-about .about-phase__name {
  font-size: 17px;
  font-weight: 600;
  color: var(--c-snow);
}

.page-about .about-phase__hint {
  font-size: 11px;
  letter-spacing: .14em;
  color: rgba(251, 250, 247, .5);
}

.page-about .about-phase__body {
  padding: 0 18px 20px;
  font-size: 15.5px;
  line-height: 1.82;
  color: rgba(251, 250, 247, .82);
}

.page-about .about-phase__body p {
  margin: 0;
  max-width: 46em;
}

/* ---------- 团队分工 ---------- */
.page-about .about-teams {
  margin-top: clamp(26px, 3.4vw, 40px);
}

@media (min-width: 940px) {
  .page-about .about-teams {
    display: grid;
    grid-template-columns: minmax(0, 1fr) 300px;
    gap: clamp(26px, 3.4vw, 44px);
    align-items: start;
  }
}

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

.page-about .about-team {
  display: grid;
  grid-template-columns: 58px minmax(0, 1fr);
  gap: 0 18px;
  padding: 22px 16px;
  border-top: var(--about-line);
  transition: background-color .2s ease, box-shadow .2s ease;
}

.page-about .about-team:last-child {
  border-bottom: var(--about-line);
}

.page-about .about-team:hover {
  background: var(--c-mist);
  box-shadow: inset 3px 0 0 var(--c-gold);
}

.page-about .about-team__num {
  font-size: 12px;
  letter-spacing: .16em;
  color: var(--c-stone);
  padding-top: 4px;
  transition: color .2s ease;
}

.page-about .about-team:hover .about-team__num { color: var(--c-primary); }

.page-about .about-team__body h3 {
  margin: 0;
  font-size: 17.5px;
  font-weight: 600;
  color: var(--c-ink);
}

.page-about .about-team__body p {
  margin: 10px 0 0;
  font-size: 15.5px;
  line-height: 1.78;
  color: var(--c-stone);
  max-width: 40em;
}

.page-about .about-team__tags {
  font-size: 11.5px;
  letter-spacing: .08em;
  color: var(--c-stone);
  transition: color .2s ease;
}

.page-about .about-team:hover .about-team__tags {
  color: var(--c-primary);
  font-weight: 700;
}

.page-about .about-teams__figure {
  margin: clamp(26px, 3vw, 0) 0 0;
  border: 2px solid var(--c-ink);
  box-shadow: var(--shadow-hard);
  background: var(--c-mist);
  padding: 12px;
}

@media (min-width: 940px) {
  .page-about .about-teams__figure {
    margin-top: 12px;
    position: sticky;
    top: calc(var(--header-h) + 28px);
  }
}

.page-about .about-teams__figure img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  object-fit: cover;
  aspect-ratio: 1 / 1;
}

.page-about .about-teams__caption {
  margin: 12px 0 0;
  font-size: 11.5px;
  letter-spacing: .12em;
  color: var(--c-stone);
  text-align: center;
}

/* ---------- 覆盖与节奏 ---------- */
.page-about .about-stats {
  display: grid;
  gap: 2px;
  margin-top: clamp(26px, 3.4vw, 40px);
  background: var(--c-primary);
  border: 2px solid var(--c-primary);
  box-shadow: var(--shadow-hard);
}

@media (min-width: 680px) {
  .page-about .about-stats { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

@media (min-width: 1120px) {
  .page-about .about-stats { grid-template-columns: repeat(4, minmax(0, 1fr)); }
}

.page-about .about-stat {
  background: var(--c-snow);
  padding: 22px 18px 24px;
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.page-about .about-stat__num {
  font-family: var(--font-mono);
  font-size: clamp(28px, 3.6vw, 40px);
  font-weight: 400;
  line-height: 1.05;
  letter-spacing: -.02em;
  color: var(--c-primary);
}

.page-about .about-stat__unit {
  font-size: 11.5px;
  letter-spacing: .14em;
  color: var(--c-stone);
}

.page-about .about-stat p {
  margin: 10px 0 0;
  font-size: 14.5px;
  line-height: 1.72;
  color: var(--c-stone);
}

.page-about .about-rhythm {
  margin-top: clamp(26px, 3.4vw, 38px);
  display: grid;
  gap: 16px;
  padding-left: 22px;
  border-left: 3px solid var(--c-gold);
}

.page-about .about-rhythm p {
  margin: 0;
  max-width: 40em;
  font-size: 16px;
  line-height: 1.82;
  color: var(--c-ink);
}

/* ---------- 收藏之后 ---------- */
.page-about .about-keep {
  margin-top: clamp(26px, 3.4vw, 40px);
  display: grid;
  gap: 0;
}

@media (min-width: 760px) {
  .page-about .about-keep {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 0 clamp(24px, 3vw, 44px);
  }
}

.page-about .about-keep__item {
  padding: 22px 0;
  border-top: 2px solid var(--c-mist);
}

@media (min-width: 760px) {
  .page-about .about-keep__item:nth-child(-n+2) {
    border-top-color: var(--c-primary);
  }
  .page-about .about-keep__item:nth-child(odd) {
    padding-right: 8px;
  }
}

.page-about .about-keep__item h3 {
  margin: 0;
  font-size: 17px;
  font-weight: 600;
  color: var(--c-ink);
  position: relative;
  padding-left: 16px;
}

.page-about .about-keep__item h3::before {
  content: "";
  position: absolute;
  left: 0;
  top: .55em;
  width: 8px;
  height: 8px;
  background: var(--c-gold);
}

.page-about .about-keep__item p {
  margin: 12px 0 0;
  font-size: 15.5px;
  line-height: 1.8;
  color: var(--c-stone);
}

.page-about .about-cta {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: clamp(28px, 4vw, 42px);
  padding-top: clamp(24px, 3vw, 34px);
  border-top: 2px solid var(--c-ink);
}

/* ---------- 浮动索引入口 ---------- */
.page-about .about-float {
  position: fixed;
  right: clamp(14px, 2.6vw, 32px);
  bottom: clamp(14px, 2.6vw, 32px);
  z-index: 40;
  display: none;
  align-items: center;
  gap: 8px;
  padding: 10px 16px;
  background: var(--c-snow);
  color: var(--c-deep);
  border: 2px solid var(--c-ink);
  box-shadow: var(--shadow-hard);
  font-size: 12px;
  letter-spacing: .16em;
  text-decoration: none;
  transition: transform .18s ease, background-color .18s ease, color .18s ease;
}

.page-about .about-float:hover {
  background: var(--c-gold);
  transform: translateY(-2px);
}

@media (min-width: 1024px) {
  .page-about .about-float { display: inline-flex; }
}

/* ---------- 窄屏兜底 ---------- */
@media (max-width: 560px) {
  .page-about .about-hero h1 {
    font-size: clamp(26px, 8.4vw, 38px);
    max-width: none;
  }
  .page-about .about-section h2 {
    font-size: clamp(22px, 6.6vw, 30px);
    max-width: none;
  }
  .page-about .about-team {
    grid-template-columns: 40px minmax(0, 1fr);
    gap: 0 12px;
    padding: 20px 10px;
  }
  .page-about .about-flow__step {
    padding: 18px 16px 20px;
  }
  .page-about .about-rhythm {
    padding-left: 14px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-who__card,
  .page-about .about-roster-list li,
  .page-about .about-float,
  .page-about .about-phase,
  .page-about .about-team {
    transition: none;
  }
  .page-about .about-who__card:hover,
  .page-about .about-roster-list li:hover,
  .page-about .about-float:hover {
    transform: none;
  }
}