.page-about {
  --about-rail: 240px;
  --about-grid-line: rgba(217, 199, 166, .5);
  background: var(--paper);
  color: var(--ink);
  padding-bottom: clamp(56px, 8vw, 110px);
}

.page-about .container {
  max-width: 1200px;
}

.page-about a:focus-visible,
.page-about button:focus-visible,
.page-about summary:focus-visible {
  outline: 2px solid var(--red);
  outline-offset: 3px;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  padding: clamp(24px, 4vw, 56px) 0 clamp(34px, 5.5vw, 68px);
  border-bottom: 1px solid var(--rule);
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image:
    linear-gradient(var(--about-grid-line) 1px, transparent 1px),
    linear-gradient(90deg, var(--about-grid-line) 1px, transparent 1px);
  background-size: 48px 48px;
  opacity: .55;
  -webkit-mask-image: radial-gradient(130% 100% at 86% 0%, #000 0%, transparent 72%);
  mask-image: radial-gradient(130% 100% at 86% 0%, #000 0%, transparent 72%);
}

.page-about .about-hero > .container {
  position: relative;
  z-index: 1;
}

.page-about .about-hero__eyebrow {
  margin: 0 0 1rem;
  font-size: .75rem;
  letter-spacing: .2em;
  color: var(--blue);
}

.page-about .about-hero__title {
  margin: 0 0 .8rem;
  max-width: 19em;
  font-family: var(--font-head);
  font-size: clamp(1.75rem, 1.2rem + 3vw, 3rem);
  font-weight: 600;
  line-height: 1.28;
  letter-spacing: -.01em;
  color: var(--ink);
}

.page-about .about-hero__lead {
  max-width: 42em;
  margin: 0;
  font-size: clamp(1rem, .96rem + .3vw, 1.125rem);
  line-height: 1.9;
  color: var(--ink);
}

.page-about .about-hero__facts {
  list-style: none;
  margin: clamp(24px, 4vw, 42px) 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--rule);
  border: 1px solid var(--rule);
}

.page-about .about-hero__facts li {
  display: flex;
  flex-direction: column;
  gap: .2rem;
  padding: .9rem 1rem;
  background: var(--paper);
}

.page-about .about-fact__n {
  font-family: var(--font-mono);
  font-size: clamp(1.05rem, .98rem + .5vw, 1.32rem);
  letter-spacing: -.01em;
  color: var(--blue);
}

.page-about .about-fact__t {
  font-size: .8125rem;
  line-height: 1.55;
  color: var(--ink-2);
}

/* ---------- 主体双栏 ---------- */
.page-about .about-body {
  max-width: 1200px;
  margin: 0 auto;
  padding: clamp(32px, 5vw, 68px) clamp(20px, 4vw, 40px) 0;
  display: grid;
  gap: clamp(26px, 4vw, 44px);
}

.page-about .about-index {
  padding: .9rem 1rem;
  background: var(--glass);
  border: 1px solid var(--glass-line);
  border-radius: 4px;
  -webkit-backdrop-filter: blur(6px);
  backdrop-filter: blur(6px);
}

.page-about .about-index__title {
  margin: 0 0 .6rem;
  font-size: .7rem;
  letter-spacing: .2em;
  color: var(--mono-ink);
}

.page-about .about-index__list {
  list-style: none;
  margin: 0;
  padding: 0 0 .3rem;
  display: flex;
  gap: .4rem;
  overflow-x: auto;
  scrollbar-width: none;
}

.page-about .about-index__list::-webkit-scrollbar {
  display: none;
}

.page-about .about-index__list a {
  display: inline-flex;
  align-items: center;
  gap: .45rem;
  padding: .4rem .8rem;
  border: 1px solid var(--rule);
  border-radius: 999px;
  font-size: .875rem;
  color: var(--ink);
  text-decoration: none;
  white-space: nowrap;
  transition: color .2s var(--ease), border-color .2s var(--ease), background .2s var(--ease);
}

.page-about .about-index__list a .mono {
  font-size: .72rem;
  color: var(--mono-ink);
}

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

/* ---------- 章节 ---------- */
.page-about .about-sec {
  padding-block: clamp(34px, 5vw, 72px);
  border-top: 1px solid var(--rule);
}

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

.page-about .about-sec__head {
  margin-bottom: clamp(16px, 2.5vw, 26px);
}

.page-about .chapter-num {
  display: block;
  margin-bottom: .7rem;
  font-family: var(--font-mono);
  font-size: .78rem;
  letter-spacing: .2em;
  color: var(--red);
}

.page-about .about-sec h2 {
  margin: 0;
  max-width: 24em;
  font-family: var(--font-head);
  font-size: clamp(1.4rem, 1.08rem + 1.5vw, 2.1rem);
  font-weight: 600;
  line-height: 1.32;
  letter-spacing: -.01em;
  color: var(--ink);
}

.page-about .about-sec__intro {
  max-width: 40em;
  margin: 0 0 clamp(20px, 3vw, 32px);
  font-size: 1rem;
  line-height: 1.85;
  color: var(--ink-2);
}

.page-about .prose {
  max-width: 40em;
}

.page-about .prose p {
  margin: 0 0 1.15em;
  font-size: 1.0625rem;
  line-height: 1.88;
  color: var(--ink);
}

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

.page-about .prose a {
  color: var(--blue);
  text-decoration: underline;
  text-decoration-color: var(--red);
  text-underline-offset: 3px;
  text-decoration-thickness: 1px;
}

.page-about .prose a:hover {
  color: var(--red-deep);
}

.page-about .about-pull {
  margin: 1.7em 0;
  padding-left: 1.05rem;
  border-left: 3px solid var(--blue);
  font-family: var(--font-head);
  font-size: clamp(1.12rem, 1rem + .7vw, 1.45rem);
  font-weight: 600;
  line-height: 1.62;
  color: var(--blue);
}

/* ---------- 图片 ---------- */
.page-about .about-figure {
  margin: 0 0 clamp(24px, 4vw, 40px);
}

.page-about .about-figure img,
.page-about .about-team__figure img,
.page-about .about-reach__figure img {
  display: block;
  width: 100%;
  height: auto;
  max-width: 100%;
  object-fit: cover;
  border: 1px solid var(--rule);
  background: var(--paper-2);
}

.page-about .about-figcap {
  display: block;
  margin-top: .6rem;
  font-size: .75rem;
  letter-spacing: .08em;
  color: var(--mono-ink);
}

/* ---------- 时间线 ---------- */
.page-about .about-timeline {
  position: relative;
  list-style: none;
  margin: clamp(24px, 3.5vw, 40px) 0 0;
  padding: 0;
}

.page-about .about-timeline::before {
  content: "";
  position: absolute;
  left: 6px;
  top: .5rem;
  bottom: .5rem;
  width: 1px;
  background: linear-gradient(180deg, var(--rule) 0%, rgba(217, 199, 166, 0) 94%);
}

.page-about .about-timeline__item {
  position: relative;
  padding: 0 0 clamp(22px, 3vw, 34px) 2.1rem;
}

.page-about .about-timeline__item::before {
  content: "";
  position: absolute;
  left: 0;
  top: .5rem;
  width: 13px;
  height: 13px;
  border-radius: 50%;
  background: var(--paper);
  border: 1px solid var(--rule);
  transition: border-color .22s var(--ease), background .22s var(--ease);
}

.page-about .about-timeline__item:hover::before,
.page-about .about-timeline__item:focus-within::before {
  border-color: var(--blue);
}

.page-about .about-timeline__item--now::before {
  background: var(--red);
  border-color: var(--red);
}

.page-about .about-timeline__year {
  display: block;
  margin-bottom: .3rem;
  font-size: .8125rem;
  letter-spacing: .14em;
  color: var(--mono-ink);
}

.page-about .about-timeline__body h3 {
  margin: 0 0 .35rem;
  font-family: var(--font-head);
  font-size: 1.0625rem;
  font-weight: 600;
  line-height: 1.5;
  color: var(--ink);
}

.page-about .about-timeline__body > p {
  margin: 0;
  max-width: 36em;
  font-size: .9688rem;
  line-height: 1.8;
  color: var(--ink);
}

.page-about .about-timeline__more {
  display: grid;
  grid-template-rows: 1fr;
  margin: .45rem 0 0;
  opacity: 1;
  transition: grid-template-rows .3s var(--ease), opacity .3s var(--ease), margin-top .3s var(--ease);
}

.page-about .about-timeline__more > span {
  display: block;
  min-height: 0;
  overflow: hidden;
  font-size: .9063rem;
  line-height: 1.78;
  color: var(--ink-2);
}

/* ---------- 团队标签 ---------- */
.page-about .about-team {
  display: grid;
  gap: clamp(24px, 4vw, 40px);
}

.page-about .tabs__list {
  display: flex;
  flex-wrap: wrap;
  gap: .4rem;
  margin: 0 0 1.2rem;
  padding: 0 0 .55rem;
  border-bottom: 1px solid var(--rule);
}

.page-about .tabs__tab {
  appearance: none;
  padding: .48rem .95rem;
  border: 1px solid var(--rule);
  border-radius: 999px;
  background: transparent;
  font: inherit;
  font-size: .9375rem;
  color: var(--ink);
  cursor: pointer;
  transition: background .2s var(--ease), color .2s var(--ease), border-color .2s var(--ease);
}

.page-about .tabs__tab:hover {
  border-color: var(--blue);
  color: var(--blue);
}

.page-about .tabs__tab[aria-selected="true"] {
  background: var(--blue);
  border-color: var(--blue);
  color: var(--on-dark);
}

.page-about .tabs__panel {
  animation: about-panel-in .3s var(--ease) both;
}

.page-about .tabs__panel h3 {
  margin: 0 0 .6rem;
  font-family: var(--font-head);
  font-size: 1.15rem;
  font-weight: 600;
  line-height: 1.5;
  color: var(--ink);
}

.page-about .tabs__panel > p {
  margin: 0;
  max-width: 36em;
  font-size: .9688rem;
  line-height: 1.85;
  color: var(--ink);
}

@keyframes about-panel-in {
  from { opacity: 0; transform: translateY(12px); }
  to { opacity: 1; transform: none; }
}

.page-about .about-list {
  list-style: none;
  margin: 1rem 0 0;
  padding: 0;
  display: grid;
  gap: .5rem;
}

.page-about .about-list li {
  position: relative;
  padding-left: 1.15rem;
  font-size: .9375rem;
  line-height: 1.75;
  color: var(--ink-2);
}

.page-about .about-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: .78em;
  width: 7px;
  height: 1px;
  background: var(--red);
}

.page-about .about-team__figure {
  margin: 0;
}

/* ---------- 覆盖范围 ---------- */
.page-about .about-reach {
  display: grid;
  gap: clamp(24px, 4vw, 42px);
}

.page-about .about-reach__figure {
  margin: 0;
}

.page-about .about-reach__body .prose p {
  font-size: 1rem;
}

.page-about .about-stats {
  margin: clamp(20px, 3vw, 30px) 0 0;
  border-top: 1px solid var(--rule);
}

.page-about .about-stats__item {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 1rem;
  padding: .78rem 0;
  border-bottom: 1px solid var(--rule);
}

.page-about .about-stats dt {
  font-size: .9375rem;
  line-height: 1.6;
  color: var(--ink-2);
}

.page-about .about-stats dd {
  margin: 0;
  font-family: var(--font-mono);
  font-size: .9688rem;
  color: var(--blue);
  white-space: nowrap;
}

/* ---------- 维护方式卡片 ---------- */
.page-about .about-care {
  display: grid;
  gap: clamp(14px, 2.2vw, 22px);
}

.page-about .about-care__card {
  padding: clamp(18px, 2.6vw, 30px);
  background: var(--paper-2);
  border: 1px solid var(--rule);
  border-radius: 4px;
  box-shadow: var(--shadow-card);
}

.page-about .about-care__k {
  display: inline-block;
  margin-bottom: .7rem;
  padding: .18rem .55rem;
  border: 1px solid var(--glass-line);
  background: var(--glass);
  border-radius: 999px;
  font-size: .7rem;
  letter-spacing: .14em;
  color: var(--blue);
}

.page-about .about-care__card h3 {
  margin: 0 0 .6rem;
  font-family: var(--font-head);
  font-size: 1.1rem;
  font-weight: 600;
  line-height: 1.5;
  color: var(--ink);
}

.page-about .about-care__card p {
  margin: 0;
  font-size: .9375rem;
  line-height: 1.85;
  color: var(--ink);
}

/* ---------- 折叠面板 ---------- */
.page-about .about-acc {
  margin-top: clamp(18px, 3vw, 30px);
  border-top: 1px solid var(--rule);
}

.page-about .about-acc__item {
  border-bottom: 1px solid var(--rule);
}

.page-about .about-acc__item summary {
  position: relative;
  padding: 1rem 2.2rem 1rem 0;
  font-family: var(--font-head);
  font-size: 1.0625rem;
  font-weight: 600;
  line-height: 1.55;
  color: var(--ink);
  cursor: pointer;
  list-style: none;
  transition: color .2s var(--ease);
}

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

.page-about .about-acc__item summary:hover {
  color: var(--blue);
}

.page-about .about-acc__item summary::after {
  content: "";
  position: absolute;
  right: .45rem;
  top: 50%;
  width: 9px;
  height: 9px;
  border-right: 1.5px solid var(--blue);
  border-bottom: 1.5px solid var(--blue);
  transform: translateY(-70%) rotate(45deg);
  transition: transform .24s var(--ease);
}

.page-about .about-acc__item[open] summary::after {
  transform: translateY(-30%) rotate(-135deg);
}

.page-about .about-acc__body {
  padding: 0 2.2rem 1.2rem 0;
}

.page-about .about-acc__body p {
  margin: 0;
  max-width: 44em;
  font-size: .9375rem;
  line-height: 1.85;
  color: var(--ink-2);
}

/* ---------- 结尾引导 ---------- */
.page-about .about-cta {
  position: relative;
  overflow: hidden;
  margin-top: clamp(44px, 7vw, 92px);
  padding: clamp(26px, 4.5vw, 54px);
  border-radius: 4px;
  background: var(--blue-deep);
  color: var(--on-dark);
}

.page-about .about-cta::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image:
    linear-gradient(rgba(247, 241, 230, .07) 1px, transparent 1px),
    linear-gradient(90deg, rgba(247, 241, 230, .07) 1px, transparent 1px);
  background-size: 36px 36px;
}

.page-about .about-cta > * {
  position: relative;
  z-index: 1;
}

.page-about .about-cta h2 {
  margin: 0 0 .7rem;
  max-width: 22em;
  font-family: var(--font-head);
  font-size: clamp(1.3rem, 1.05rem + 1.2vw, 1.85rem);
  font-weight: 600;
  line-height: 1.4;
  color: var(--on-dark);
}

.page-about .about-cta p {
  margin: 0;
  max-width: 40em;
  font-size: .9688rem;
  line-height: 1.85;
  color: var(--on-dark-2);
}

.page-about .about-cta__links {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: .6rem;
  margin: 1.5rem 0 0;
  padding: 0;
}

.page-about .about-cta__links a {
  display: inline-block;
  padding: .55rem 1.05rem;
  border: 1px solid rgba(247, 241, 230, .36);
  border-radius: 999px;
  font-size: .9375rem;
  color: var(--on-dark);
  text-decoration: none;
  transition: background .22s var(--ease), color .22s var(--ease), border-color .22s var(--ease);
}

.page-about .about-cta__links a:hover {
  background: var(--paper);
  border-color: var(--paper);
  color: var(--blue-deep);
}

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

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

  .page-about .about-care__card:first-child {
    grid-column: 1 / -1;
  }
}

@media (min-width: 860px) {
  .page-about .about-reach {
    grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
    align-items: start;
  }

  .page-about .about-team {
    grid-template-columns: minmax(0, 7fr) minmax(0, 4fr);
    align-items: start;
  }

  .page-about .about-team__figure {
    margin-top: clamp(26px, 5vw, 54px);
  }
}

@media (min-width: 980px) {
  .page-about .about-body {
    grid-template-columns: var(--about-rail) minmax(0, 1fr);
    gap: clamp(36px, 4vw, 60px);
  }

  .page-about .about-index {
    position: sticky;
    top: 1.5rem;
    align-self: start;
    padding: 1.1rem 1rem 1.1rem 1.1rem;
  }

  .page-about .about-index__list {
    flex-direction: column;
    gap: 0;
    padding: 0;
    overflow: visible;
    border-left: 1px solid var(--rule);
  }

  .page-about .about-index__list a {
    position: relative;
    width: 100%;
    padding: .55rem 0 .55rem 1rem;
    border: 0;
    border-radius: 0;
    white-space: normal;
    font-size: .9375rem;
    color: var(--ink-2);
  }

  .page-about .about-index__list a::before {
    content: "";
    position: absolute;
    left: -1px;
    top: .42rem;
    bottom: .42rem;
    width: 2px;
    background: transparent;
    transition: background .2s var(--ease);
  }

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

  .page-about .about-index__list a:hover::before,
  .page-about .about-index__list a:focus-visible::before {
    background: var(--blue);
  }
}

@media (min-width: 980px) and (hover: hover) {
  .page-about .about-timeline__more {
    grid-template-rows: 0fr;
    margin-top: 0;
    opacity: 0;
  }

  .page-about .about-timeline__item:hover .about-timeline__more,
  .page-about .about-timeline__item:focus-within .about-timeline__more {
    grid-template-rows: 1fr;
    margin-top: .5rem;
    opacity: 1;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-timeline__more,
  .page-about .tabs__panel,
  .page-about .about-acc__item summary::after,
  .page-about .about-timeline__item::before,
  .page-about .about-index__list a,
  .page-about .tabs__tab {
    transition: none;
    animation: none;
  }
}