.page-about {
  --about-line: rgba(169, 180, 216, 0.22);
  --about-panel: rgba(21, 28, 61, 0.62);
  --tl-pad: 26px;
  --tl-axis: 6px;
  position: relative;
  overflow-x: clip;
  color: var(--paper);
}

.page-about__wrap {
  padding-block: clamp(18px, 3vw, 32px) clamp(56px, 9vw, 96px);
}

/* ---------- 面包屑 ---------- */
.page-about .breadcrumbs {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  margin-bottom: clamp(18px, 3.5vw, 36px);
  font-size: var(--step--1);
  letter-spacing: 0.06em;
  color: var(--mist);
}

.page-about .breadcrumbs__item {
  color: var(--mist);
  text-decoration: none;
}

.page-about .breadcrumbs a.breadcrumbs__item:hover {
  color: var(--cyan);
}

.page-about .breadcrumbs__item[aria-current="page"] {
  color: var(--paper);
}

.page-about .breadcrumbs__sep {
  color: rgba(169, 180, 216, 0.5);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  isolation: isolate;
  padding-block: clamp(16px, 3vw, 40px) clamp(38px, 6vw, 72px);
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  z-index: -1;
  inset: -34% -18% -12% -32%;
  pointer-events: none;
  background:
    radial-gradient(46% 56% at 26% 34%, rgba(27, 42, 107, 0.95), transparent 72%),
    radial-gradient(30% 42% at 74% 10%, rgba(53, 240, 208, 0.13), transparent 70%);
}

.page-about .about-hero__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(26px, 5vw, 54px);
}

.page-about .about-hero__eyebrow {
  margin: 0 0 14px;
  font-family: var(--font-mono);
  font-size: var(--step--1);
  letter-spacing: 0.26em;
  text-transform: uppercase;
  color: var(--cyan);
}

.page-about .about-hero h1 {
  margin: 0 0 18px;
  font-family: var(--font-display);
  font-size: clamp(29px, 5vw, var(--step-4));
  line-height: 1.2;
  letter-spacing: 0.01em;
  color: var(--paper);
}

.page-about .about-hero .lede {
  max-width: 60ch;
  margin: 0 0 26px;
  color: var(--mist);
  line-height: 1.85;
}

.page-about .about-hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.page-about .about-facts {
  align-self: end;
  padding: clamp(18px, 3vw, 26px);
  border: 1px solid var(--about-line);
  border-radius: var(--radius);
  background: linear-gradient(158deg, rgba(21, 28, 61, 0.94), rgba(11, 16, 48, 0.72));
  box-shadow: 7px 7px 0 rgba(217, 210, 190, 0.05);
}

.page-about .about-facts__label {
  margin: 0 0 14px;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--about-line);
  font-size: var(--step--1);
  letter-spacing: 0.18em;
  color: var(--warm);
}

.page-about .about-facts__list {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px 12px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .about-facts__row {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.page-about .about-facts__num {
  font-size: var(--step-2);
  line-height: 1.1;
  color: var(--cyan);
  letter-spacing: 0.02em;
}

.page-about .about-facts__key {
  font-size: var(--step--1);
  color: var(--mist);
}

.page-about .about-facts__note {
  margin: 16px 0 0;
  padding-top: 12px;
  border-top: 1px solid var(--about-line);
  font-size: var(--step--1);
  color: var(--mist);
  line-height: 1.7;
}

/* ---------- 区块骨架 ---------- */
.page-about .about-section {
  padding-block: clamp(34px, 6vw, 70px);
}

.page-about .about-head {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  align-items: baseline;
  gap: 6px 16px;
  margin-bottom: clamp(20px, 3vw, 32px);
  padding-bottom: 14px;
  border-bottom: 1px solid var(--about-line);
}

.page-about .about-head__num {
  font-size: var(--step-1);
  letter-spacing: 0.08em;
  color: var(--orange);
}

.page-about .about-head__title {
  margin: 0;
  font-family: var(--font-display);
  font-size: clamp(21px, 3.3vw, var(--step-3));
  line-height: 1.28;
  color: var(--paper);
}

.page-about .about-head__meta {
  grid-column: 1 / -1;
  font-family: var(--font-mono);
  font-size: var(--step--1);
  letter-spacing: 0.14em;
  color: var(--mist);
}

/* ---------- 时间线 ---------- */
.page-about .about-banner {
  margin: 0 0 clamp(28px, 5vw, 48px);
}

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

.page-about .about-timeline {
  position: relative;
  padding-left: var(--tl-pad);
}

.page-about .about-timeline::before {
  content: "";
  position: absolute;
  left: var(--tl-axis);
  top: 10px;
  bottom: 10px;
  width: 2px;
  background: linear-gradient(180deg, var(--cyan) 0%, rgba(53, 240, 208, 0.35) 55%, rgba(53, 240, 208, 0.05) 100%);
}

.page-about .tl-item {
  position: relative;
  margin-bottom: 12px;
}

.page-about .tl-item::before {
  content: "";
  position: absolute;
  left: calc(var(--tl-axis) - var(--tl-pad));
  top: 20px;
  transform: translateX(-50%);
  width: 12px;
  height: 12px;
  border-radius: 50%;
  border: 2px solid var(--cyan);
  background: var(--night);
  box-sizing: border-box;
}

.page-about .tl-item[open]::before {
  background: var(--cyan);
  box-shadow: 0 0 0 4px rgba(53, 240, 208, 0.16);
}

.page-about .tl-item__head {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 10px 18px;
  padding: 14px 16px;
  border: 1px solid var(--about-line);
  border-radius: var(--radius);
  background: var(--about-panel);
  cursor: pointer;
  list-style: none;
  transition: border-color 180ms ease, background 180ms ease;
}

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

.page-about .tl-item__head:hover {
  border-color: var(--line-strong);
}

.page-about .tl-item__head::after {
  content: "+";
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: var(--step-1);
  line-height: 1;
  color: var(--cyan);
}

.page-about .tl-item[open] .tl-item__head {
  border-color: var(--line-strong);
  background: rgba(21, 28, 61, 0.88);
  border-bottom-left-radius: 0;
  border-bottom-right-radius: 0;
}

.page-about .tl-item[open] .tl-item__head::after {
  content: "−";
}

.page-about .tl-item__year {
  font-size: var(--step--1);
  letter-spacing: 0.14em;
  color: var(--orange);
}

.page-about .tl-item__name {
  font-family: var(--font-display);
  font-size: var(--step-1);
  color: var(--paper);
}

.page-about .tl-item__body {
  padding: 14px 16px 20px;
  border: 1px solid var(--line-strong);
  border-top: 0;
  border-radius: 0 0 var(--radius) var(--radius);
  background: rgba(11, 16, 48, 0.55);
  animation: about-drop 200ms ease both;
}

.page-about .tl-item__body p {
  margin: 0;
  color: var(--mist);
  line-height: 1.85;
}

@keyframes about-drop {
  from {
    opacity: 0;
    transform: translateY(-4px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* ---------- 图文错位 ---------- */
.page-about .about-split {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(22px, 4vw, 44px);
}

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

.page-about .about-split__text p {
  margin: 0 0 16px;
  color: var(--mist);
  line-height: 1.85;
}

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

.page-about .check-list {
  margin: 0 0 18px;
  padding: 0;
  list-style: none;
  border-top: 1px solid var(--about-line);
}

.page-about .check-list li {
  position: relative;
  padding: 11px 0 11px 26px;
  border-bottom: 1px solid var(--about-line);
  color: var(--paper);
  line-height: 1.7;
}

.page-about .check-list li::before {
  content: "";
  position: absolute;
  left: 2px;
  top: 20px;
  width: 9px;
  height: 9px;
  border: 1px solid var(--cyan);
  transform: rotate(45deg);
}

/* ---------- 团队 ---------- */
.page-about .team-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(24px, 4vw, 48px);
  align-items: center;
}

.page-about .team-donut {
  position: relative;
  width: min(228px, 62vw);
  aspect-ratio: 1 / 1;
  margin-inline: auto;
}

.page-about .team-donut__ring {
  width: 100%;
  height: 100%;
  border-radius: 50%;
  background: conic-gradient(
    var(--cyan) 0deg 141deg,
    var(--orange) 141deg 274deg,
    var(--sign) 274deg 360deg
  );
  -webkit-mask: radial-gradient(circle at 50% 50%, transparent 0 57%, #000 57%);
  mask: radial-gradient(circle at 50% 50%, transparent 0 57%, #000 57%);
}

.page-about .team-donut__center {
  position: absolute;
  inset: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 2px;
  pointer-events: none;
}

.page-about .team-donut__total {
  font-size: var(--step-4);
  line-height: 1;
  color: var(--paper);
}

.page-about .team-donut__unit {
  font-size: var(--step--1);
  letter-spacing: 0.2em;
  color: var(--mist);
}

.page-about .team-legend {
  display: grid;
  gap: 10px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .team-legend__item {
  display: grid;
  grid-template-columns: auto auto minmax(0, 1fr);
  align-items: baseline;
  gap: 4px 12px;
  padding: 13px 16px;
  border: 1px solid var(--about-line);
  border-left-width: 3px;
  border-radius: var(--radius);
  background: var(--about-panel);
  transition: background 180ms ease, border-color 180ms ease;
}

.page-about .team-legend__item:hover {
  background: rgba(21, 28, 61, 0.9);
  border-color: var(--line-strong);
}

.page-about .team-legend__item--edit {
  border-left-color: var(--cyan);
}

.page-about .team-legend__item--build {
  border-left-color: var(--orange);
}

.page-about .team-legend__item--care {
  border-left-color: var(--sign);
}

.page-about .team-legend__dot {
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: currentColor;
}

.page-about .team-legend__item--edit .team-legend__dot {
  color: var(--cyan);
}

.page-about .team-legend__item--build .team-legend__dot {
  color: var(--orange);
}

.page-about .team-legend__item--care .team-legend__dot {
  color: var(--sign);
}

.page-about .team-legend__name {
  font-family: var(--font-display);
  font-size: var(--step-1);
  color: var(--paper);
}

.page-about .team-legend__count {
  justify-self: end;
  font-size: var(--step--1);
  letter-spacing: 0.08em;
  color: var(--cyan);
}

.page-about .team-legend__desc {
  grid-column: 2 / -1;
  font-size: var(--step--1);
  line-height: 1.7;
  color: var(--mist);
}

.page-about .about-footnote {
  margin: 22px 0 0;
  padding: 14px 16px;
  border-left: 2px solid var(--orange);
  background: rgba(255, 122, 26, 0.06);
  font-size: var(--step--1);
  line-height: 1.8;
  color: var(--mist);
}

/* ---------- 合作生态 ---------- */
.page-about .eco-list {
  margin: 0;
  border-top: 1px solid var(--about-line);
}

.page-about .eco-list__row {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 4px;
  padding: 12px 0;
  border-bottom: 1px solid var(--about-line);
}

.page-about .eco-list__term {
  font-family: var(--font-display);
  font-size: var(--step-0);
  color: var(--cyan);
}

.page-about .eco-list__desc {
  margin: 0;
  font-size: var(--step--1);
  line-height: 1.75;
  color: var(--mist);
}

/* ---------- 荣誉 ---------- */
.page-about .honor-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 14px;
}

.page-about .honor-card {
  border-top: 3px solid var(--cyan);
}

.page-about .honor-card:nth-child(2) {
  border-top-color: var(--orange);
}

.page-about .honor-card:nth-child(3) {
  border-top-color: var(--warm);
}

.page-about .honor-card .paper-card__label {
  font-family: var(--font-mono);
  letter-spacing: 0.18em;
  color: var(--orange);
}

.page-about .honor-card .paper-card__title {
  font-family: var(--font-display);
  line-height: 1.4;
}

.page-about .honor-card .paper-card__body {
  line-height: 1.75;
}

/* ---------- 栏目索引 ---------- */
.page-about .column-index {
  display: grid;
  gap: 0;
  margin: 0;
  padding: 0;
  list-style: none;
  border-top: 1px solid var(--about-line);
  counter-reset: none;
}

.page-about .column-index__item {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 4px 18px;
  padding: 16px 0;
  border-bottom: 1px solid var(--about-line);
  transition: background 180ms ease;
}

.page-about .column-index__item:hover {
  background: rgba(21, 28, 61, 0.5);
}

.page-about .column-index__no {
  font-size: var(--step--1);
  letter-spacing: 0.12em;
  color: var(--orange);
  padding-top: 4px;
}

.page-about .column-index__name {
  margin: 0 0 6px;
  font-family: var(--font-display);
  font-size: var(--step-1);
  color: var(--paper);
}

.page-about .column-index__desc {
  margin: 0;
  font-size: var(--step--1);
  line-height: 1.78;
  color: var(--mist);
}

/* ---------- 收尾 ---------- */
.page-about .about-cta {
  margin-top: clamp(38px, 6vw, 72px);
}

.page-about .about-cta__inner {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(20px, 4vw, 40px);
  padding: clamp(24px, 4vw, 44px);
  border: 1px solid var(--line-strong);
  border-radius: var(--radius);
  background:
    linear-gradient(140deg, rgba(27, 42, 107, 0.85), rgba(11, 16, 48, 0.9) 62%),
    var(--night);
}

.page-about .about-cta__title {
  margin: 0 0 12px;
  font-family: var(--font-display);
  font-size: clamp(20px, 3vw, var(--step-2));
  line-height: 1.35;
  color: var(--paper);
}

.page-about .about-cta__text p {
  margin: 0;
  max-width: 62ch;
  color: var(--mist);
  line-height: 1.85;
}

.page-about .about-cta__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  align-content: start;
}

/* ---------- 响应式 ---------- */
@media (min-width: 700px) {
  .page-about .about-head {
    grid-template-columns: auto minmax(0, 1fr) auto;
  }

  .page-about .about-head__meta {
    grid-column: 3;
  }

  .page-about .eco-list__row {
    grid-template-columns: minmax(0, 0.7fr) minmax(0, 1.3fr);
    align-items: baseline;
    gap: 6px 20px;
  }

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

@media (min-width: 880px) {
  .page-about {
    --tl-pad: 34px;
  }

  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 1.55fr) minmax(0, 1fr);
    align-items: end;
  }

  .page-about .about-split {
    grid-template-columns: minmax(0, 0.92fr) minmax(0, 1.08fr);
    align-items: start;
  }

  .page-about .about-split--reverse {
    grid-template-columns: minmax(0, 1.08fr) minmax(0, 0.92fr);
  }

  .page-about .about-split--reverse .about-split__visual {
    order: 2;
  }

  .page-about .about-split--reverse .about-split__text {
    order: 1;
  }

  .page-about .team-layout {
    grid-template-columns: minmax(0, 0.72fr) minmax(0, 1.28fr);
  }

  .page-about .team-legend__desc {
    max-height: 0;
    overflow: hidden;
    opacity: 0;
    transition: max-height 220ms ease, opacity 220ms ease;
  }

  .page-about .team-legend__item:hover .team-legend__desc {
    max-height: 8em;
    opacity: 1;
  }

  .page-about .about-cta__inner {
    grid-template-columns: minmax(0, 1.4fr) minmax(0, 0.6fr);
    justify-content: space-between;
    align-items: center;
  }

  .page-about .about-cta__actions {
    justify-content: flex-end;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .tl-item__body {
    animation: none;
  }

  .page-about .tl-item__head,
  .page-about .team-legend__item,
  .page-about .column-index__item,
  .page-about .team-legend__desc {
    transition: none;
  }
}