.page-about {
  --about-body: #C6D1E1;
  --about-dim: var(--mist);
  background: var(--night);
  color: var(--text);
  padding-bottom: clamp(2.5rem, 7vw, 5rem);
  overflow-x: hidden;
}

.page-about .about-crumbs {
  padding-top: clamp(1rem, 2.5vw, 1.6rem);
}

/* ---------- 首屏 ---------- */
.page-about .brand-hero {
  position: relative;
  margin-top: clamp(1rem, 2.5vw, 1.75rem);
  padding: clamp(1.75rem, 4.5vw, 3.25rem) 0 clamp(2.25rem, 5.5vw, 4.25rem);
  background:
    radial-gradient(90% 120% at 6% -12%, rgba(201, 162, 39, .16), transparent 62%),
    linear-gradient(180deg, var(--panel) 0%, var(--night) 90%);
  border-top: 1px solid var(--hair);
  border-bottom: 1px solid var(--hair);
}

.page-about .brand-hero__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(1.5rem, 4vw, 3rem);
  align-items: end;
}

.page-about .brand-hero__media .figure {
  margin: 0;
  border: 1px solid var(--hair-soft);
  background: var(--card);
}

.page-about .brand-hero__media .figure__img {
  aspect-ratio: 11 / 14;
  object-fit: cover;
}

.page-about .brand-hero__title {
  font-family: var(--serif);
  font-weight: 700;
  font-size: clamp(2rem, 6vw, 3.4rem);
  line-height: 1.1;
  letter-spacing: -.015em;
  color: #FBF6EA;
  margin: .45rem 0 1rem;
}

.page-about .brand-hero__text .lede {
  color: var(--about-body);
  font-size: clamp(1rem, 1.9vw, 1.1rem);
  line-height: 1.85;
  margin: 0;
  max-width: 60ch;
}

.page-about .hero-facts {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1rem 1.25rem;
  margin: clamp(1.5rem, 3.5vw, 2.2rem) 0 0;
  padding-top: clamp(1rem, 2.5vw, 1.5rem);
  border-top: 1px solid var(--hair);
}

.page-about .hero-fact {
  margin: 0;
}

.page-about .hero-fact__num {
  display: block;
  margin: 0;
  font-family: var(--mono);
  font-size: clamp(1.25rem, 2.6vw, 1.7rem);
  letter-spacing: .02em;
  color: var(--gold-soft);
}

.page-about .hero-fact__label {
  display: block;
  margin-top: .35rem;
  font-size: .82rem;
  letter-spacing: .08em;
  color: var(--about-dim);
}

/* ---------- 通用跨页骨架 ---------- */
.page-about .ledger {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(1.1rem, 3vw, 1.75rem);
}

.page-about .ledger__mark {
  position: relative;
  align-self: start;
  padding-left: 1rem;
  border-left: 1px solid var(--hair);
}

.page-about .ledger__mark::before {
  content: "";
  position: absolute;
  left: -3px;
  top: .4rem;
  width: 6px;
  height: 6px;
  background: var(--gold);
}

.page-about .ledger__code {
  display: block;
  font-family: var(--mono);
  font-size: .76rem;
  letter-spacing: .2em;
  color: var(--gold);
}

.page-about .ledger__label {
  display: block;
  margin-top: .45rem;
  font-size: .9rem;
  letter-spacing: .05em;
  color: var(--about-dim);
}

.page-about .stage-title {
  font-family: var(--serif);
  font-weight: 700;
  font-size: clamp(1.65rem, 4vw, 2.5rem);
  line-height: 1.2;
  letter-spacing: -.01em;
  color: var(--paper);
  margin: 0 0 1.1rem;
}

.page-about .ledger__body > p {
  margin: 0 0 1.05rem;
  max-width: 64ch;
  line-height: 1.85;
  color: var(--about-body);
}

.page-about .inline-link {
  color: var(--gold-soft);
  text-decoration: none;
  border-bottom: 1px solid var(--hair);
  padding-bottom: 1px;
  transition: border-color .25s var(--ease), color .25s var(--ease);
}

.page-about .inline-link:hover,
.page-about .inline-link:focus-visible {
  color: var(--paper);
  border-bottom-color: var(--gold);
}

/* ---------- 奶油纸旁注 ---------- */
.page-about .note-card {
  margin: clamp(1.2rem, 3vw, 1.8rem) 0;
  padding: clamp(1rem, 2.6vw, 1.6rem) clamp(1.05rem, 2.8vw, 1.8rem);
  background: var(--paper);
  color: var(--ink);
  border-left: 3px solid var(--gold);
  border-radius: 0;
}

.page-about .note-card__num {
  display: block;
  font-family: var(--mono);
  font-size: clamp(1.15rem, 2.6vw, 1.5rem);
  letter-spacing: .02em;
  color: var(--ink);
}

.page-about .note-card__text {
  display: block;
  margin-top: .45rem;
  font-size: .95rem;
  line-height: 1.8;
  color: var(--ink);
  max-width: 58ch;
}

/* ---------- 时间线 ---------- */
.page-about .timeline {
  list-style: none;
  margin: clamp(1.5rem, 3.5vw, 2.4rem) 0 0;
  padding: 0;
}

.page-about .timeline__item {
  position: relative;
  padding: 0 0 clamp(1.6rem, 4vw, 2.6rem) clamp(1.1rem, 3vw, 2rem);
  border-left: 1px solid var(--hair);
}

.page-about .timeline__item:last-child {
  padding-bottom: 0;
  border-left-color: rgba(201, 162, 39, .08);
}

.page-about .timeline__item::before {
  content: "";
  position: absolute;
  left: 0;
  top: .5rem;
  width: 7px;
  height: 7px;
  transform: translateX(-50%);
  background: var(--gold);
}

.page-about .stage__code {
  display: block;
  margin-bottom: .45rem;
  font-family: var(--mono);
  font-size: .74rem;
  letter-spacing: .2em;
  color: var(--gold);
}

.page-about .stage__title {
  font-family: var(--serif);
  font-weight: 700;
  font-size: clamp(1.2rem, 2.7vw, 1.55rem);
  line-height: 1.35;
  color: var(--paper);
  margin: 0 0 .6rem;
}

.page-about .timeline__item p {
  margin: 0 0 .85rem;
  max-width: 62ch;
  line-height: 1.85;
  color: var(--about-body);
  font-size: .97rem;
}

.page-about .stage__data {
  margin: 0;
  padding-top: .55rem;
  border-top: 1px solid var(--hair-soft);
  font-family: var(--mono);
  font-size: .8rem;
  letter-spacing: .05em;
  color: var(--gold-soft);
}

.page-about .chronicle-break {
  list-style: none;
  position: relative;
  margin: 0 0 clamp(1.6rem, 4vw, 2.6rem);
  padding-left: clamp(1.1rem, 3vw, 2rem);
  border-left: 1px solid var(--hair);
}

.page-about .figure {
  margin: clamp(1.2rem, 3vw, 2rem) 0;
  border: 1px solid var(--hair-soft);
  background: var(--card);
}

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

.page-about .figure__caption {
  padding: .8rem clamp(.9rem, 2vw, 1.2rem);
  font-size: .84rem;
  line-height: 1.7;
  letter-spacing: .02em;
  color: var(--about-dim);
  border-top: 1px solid var(--hair-soft);
}

.page-about .team-figure {
  margin: clamp(1.3rem, 3vw, 2rem) 0;
}

/* ---------- 服务理念 ---------- */
.page-about .ethos-list {
  list-style: none;
  margin: clamp(1.4rem, 3vw, 2rem) 0 0;
  padding: 0;
  border-top: 1px solid var(--hair);
}

.page-about .ethos-item {
  position: relative;
  padding: clamp(1.1rem, 2.6vw, 1.6rem) 0 clamp(1.1rem, 2.6vw, 1.6rem) clamp(2.4rem, 5vw, 3.2rem);
  border-bottom: 1px solid var(--hair-soft);
}

.page-about .ethos-item__num {
  position: absolute;
  left: 0;
  top: clamp(1.15rem, 2.6vw, 1.65rem);
  font-family: var(--mono);
  font-size: .95rem;
  color: var(--gold);
  letter-spacing: .1em;
}

.page-about .ethos-item__title {
  font-family: var(--serif);
  font-weight: 700;
  font-size: clamp(1.05rem, 2.3vw, 1.25rem);
  color: var(--paper);
  margin: 0 0 .5rem;
  line-height: 1.4;
}

.page-about .ethos-item p {
  margin: 0;
  max-width: 60ch;
  line-height: 1.85;
  color: var(--about-body);
  font-size: .95rem;
}

/* ---------- 会员等级 ---------- */
.page-about .tier-tabs {
  margin-top: clamp(1.4rem, 3vw, 2rem);
  border-top: 1px solid var(--hair);
}

.page-about .tier-tabs .tabs__list {
  display: flex;
  flex-wrap: wrap;
  border-bottom: 1px solid var(--hair);
}

.page-about .tier-tabs .tabs__tab {
  appearance: none;
  background: transparent;
  border: 0;
  border-bottom: 2px solid transparent;
  color: var(--about-dim);
  font-family: var(--sans);
  font-size: .95rem;
  font-weight: 500;
  letter-spacing: .1em;
  padding: .85rem 1.05rem;
  cursor: pointer;
  transition: color .25s var(--ease), border-color .25s var(--ease);
}

.page-about .tier-tabs .tabs__tab:hover {
  color: var(--paper);
}

.page-about .tier-tabs .tabs__tab[aria-selected="true"] {
  color: var(--gold-soft);
  border-bottom-color: var(--gold);
}

.page-about .tier-tabs .tabs__tab:focus-visible {
  outline: 2px solid var(--gold-soft);
  outline-offset: -2px;
}

.page-about .tier-panel {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(1rem, 2.6vw, 1.75rem);
  padding: clamp(1.2rem, 3vw, 1.9rem) 0 0;
}

.page-about .tier-panel[hidden] {
  display: none;
}

.page-about .tier-panel__aside {
  border-left: 1px solid var(--hair);
  padding-left: 1rem;
}

.page-about .tier-panel__name {
  display: block;
  font-family: var(--serif);
  font-weight: 700;
  font-size: clamp(1.5rem, 3.6vw, 2.05rem);
  color: var(--gold-soft);
  letter-spacing: .04em;
}

.page-about .tier-panel__basis {
  display: block;
  margin-top: .5rem;
  font-family: var(--mono);
  font-size: .78rem;
  letter-spacing: .04em;
  line-height: 1.7;
  color: var(--about-dim);
}

.page-about .tier-panel__body p {
  margin: 0 0 .9rem;
  max-width: 62ch;
  line-height: 1.85;
  color: var(--about-body);
  font-size: .96rem;
}

.page-about .tier-panel__offer {
  margin: 0;
  padding-top: .7rem;
  border-top: 1px solid var(--hair-soft);
  font-family: var(--mono);
  font-size: .8rem;
  letter-spacing: .04em;
  line-height: 1.8;
  color: var(--gold-soft);
}

/* ---------- 安全与资质 ---------- */
.page-about .check-list {
  list-style: none;
  margin: clamp(1.3rem, 3vw, 1.9rem) 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 0;
}

.page-about .check-item {
  padding: clamp(.95rem, 2.4vw, 1.35rem) 0;
  border-bottom: 1px solid var(--hair-soft);
}

.page-about .check-item:first-child {
  border-top: 1px solid var(--hair-soft);
}

.page-about .check-item__title {
  position: relative;
  margin: 0 0 .45rem;
  padding-left: 1.15rem;
  font-family: var(--serif);
  font-weight: 700;
  font-size: clamp(1rem, 2.2vw, 1.15rem);
  color: var(--paper);
  line-height: 1.45;
}

.page-about .check-item__title::before {
  content: "";
  position: absolute;
  left: 0;
  top: .55em;
  width: 8px;
  height: 2px;
  background: var(--jade);
}

.page-about .check-item p {
  margin: 0 0 0 1.15rem;
  max-width: 60ch;
  line-height: 1.8;
  color: var(--about-body);
  font-size: .94rem;
}

/* ---------- 合作生态 ---------- */
.page-about .domain-list {
  list-style: none;
  margin: clamp(1.2rem, 3vw, 1.8rem) 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: .7rem;
}

.page-about .domain-item {
  background: var(--card);
  border: 1px solid var(--hair-soft);
  border-top: 2px solid var(--gold);
  padding: .85rem 1rem;
}

.page-about .domain-item__name {
  font-family: var(--sans);
  font-size: .92rem;
  font-weight: 500;
  letter-spacing: .08em;
  color: var(--paper);
}

.page-about .partners-lead {
  margin-top: clamp(1.4rem, 3vw, 2rem);
}

.page-about .expand {
  background: var(--panel);
  border: 1px solid var(--hair-soft);
  margin-bottom: .6rem;
}

.page-about .expand__head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  list-style: none;
  cursor: pointer;
  padding: 1rem clamp(.95rem, 2.4vw, 1.25rem);
  font-family: var(--serif);
  font-size: 1.02rem;
  font-weight: 700;
  color: var(--paper);
  letter-spacing: .02em;
}

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

.page-about .expand__head::after {
  content: "＋";
  font-family: var(--mono);
  font-weight: 400;
  font-size: .9rem;
  color: var(--gold);
  flex: none;
}

.page-about .expand[open] .expand__head::after {
  content: "－";
}

.page-about .expand__head:focus-visible {
  outline: 2px solid var(--gold-soft);
  outline-offset: -2px;
}

.page-about .expand__body {
  padding: 0 clamp(.95rem, 2.4vw, 1.25rem) 1.1rem;
}

.page-about .expand__body p {
  margin: 0;
  max-width: 62ch;
  line-height: 1.85;
  font-size: .94rem;
  color: var(--about-body);
}

/* ---------- 下一站 ---------- */
.page-about .next-list {
  list-style: none;
  margin: clamp(1.2rem, 3vw, 1.8rem) 0 0;
  padding: 0;
  border-top: 1px solid var(--hair);
}

.page-about .next-list li {
  border-bottom: 1px solid var(--hair-soft);
}

.page-about .next-list a {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: .3rem 1.25rem;
  padding: .95rem .1rem;
  font-family: var(--serif);
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--paper);
  text-decoration: none;
  transition: color .25s var(--ease), padding-left .25s var(--ease);
}

.page-about .next-list a:hover,
.page-about .next-list a:focus-visible {
  color: var(--gold-soft);
  padding-left: .5rem;
}

.page-about .next-list span {
  font-family: var(--sans);
  font-size: .86rem;
  font-weight: 400;
  letter-spacing: .02em;
  line-height: 1.7;
  color: var(--about-dim);
}

/* ---------- 侧边章节索引 ---------- */
.page-about .rail {
  display: none;
}

/* ---------- 响应式 ---------- */
@media (min-width: 720px) {
  .page-about .hero-facts {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

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

@media (min-width: 880px) {
  .page-about .brand-hero__grid {
    grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
    gap: clamp(2rem, 5vw, 4rem);
  }

  .page-about .brand-hero__text {
    padding-bottom: clamp(.5rem, 2vw, 1.5rem);
  }

  .page-about .ledger {
    grid-template-columns: minmax(0, 12.5rem) minmax(0, 1fr);
    gap: clamp(2rem, 5.5vw, 4.5rem);
  }

  .page-about .tier-panel {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1.6fr);
    gap: clamp(1.5rem, 3.5vw, 2.75rem);
  }

  .page-about .check-list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    column-gap: clamp(1.5rem, 3.5vw, 3rem);
  }
}

@media (min-width: 1560px) {
  .page-about .rail {
    display: block;
    position: fixed;
    right: 1.25rem;
    top: 50%;
    transform: translateY(-50%);
    z-index: 6;
    padding: .9rem 0 .9rem 1rem;
    border-left: 1px solid var(--hair);
    width: 8.5rem;
  }

  .page-about .rail__title {
    display: block;
    margin-bottom: .7rem;
    font-family: var(--mono);
    font-size: .66rem;
    letter-spacing: .22em;
    color: var(--about-dim);
  }

  .page-about .rail__link {
    display: block;
    padding: .3rem 0;
    font-size: .78rem;
    letter-spacing: .1em;
    color: var(--about-dim);
    text-decoration: none;
    transition: color .2s var(--ease), padding-left .2s var(--ease);
  }

  .page-about .rail__link:hover,
  .page-about .rail__link:focus-visible,
  .page-about .rail__link[aria-current="true"] {
    color: var(--gold-soft);
    padding-left: .35rem;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .next-list a,
  .page-about .inline-link,
  .page-about .tier-tabs .tabs__tab,
  .page-about .rail__link {
    transition: none;
  }

  .page-about .next-list a:hover,
  .page-about .next-list a:focus-visible {
    padding-left: .1rem;
  }
}