.page-about {
  --about-rail: 208px;
  --about-gap: clamp(20px, 3.2vw, 40px);
  padding-bottom: clamp(40px, 6vw, 88px);
}

.page-about .about-crumb {
  padding-block: 16px 4px;
}

/* ---------- 封面 ---------- */
.page-about .cover {
  position: relative;
  margin-top: 12px;
  overflow: hidden;
  isolation: isolate;
  background: var(--ink);
  border-top: 1px solid var(--line-1);
  border-bottom: 1px solid var(--line-1);
}

.page-about .cover::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  background-image:
    linear-gradient(to right, var(--line-2) 1px, transparent 1px),
    linear-gradient(to bottom, var(--line-2) 1px, transparent 1px);
  background-size: 64px 64px;
  -webkit-mask-image: linear-gradient(158deg, #000 18%, transparent 74%);
  mask-image: linear-gradient(158deg, #000 18%, transparent 74%);
}

.page-about .cover__media {
  position: absolute;
  inset: 0;
  z-index: -1;
}

.page-about .cover__media img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
  opacity: 0.52;
}

.page-about .cover__media::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(
    104deg,
    rgba(11, 16, 38, 0.97) 0%,
    rgba(11, 16, 38, 0.9) 44%,
    rgba(11, 16, 38, 0.42) 100%
  );
}

.page-about .cover__inner {
  position: relative;
  z-index: 1;
  display: grid;
  gap: 18px;
  padding-block: clamp(56px, 10vw, 124px) clamp(36px, 6vw, 68px);
}

.page-about .cover__title {
  margin: 0;
  font-family: var(--font-display);
  font-size: clamp(34px, 7.4vw, 84px);
  font-weight: 800;
  line-height: 1.04;
  letter-spacing: 0.055em;
  color: var(--paper);
  text-wrap: balance;
}

.page-about .cover__year {
  font-family: var(--font-mono);
  font-size: 0.86em;
  letter-spacing: 0.02em;
  color: var(--gold);
}

.page-about .cover__lead {
  margin: 0;
  max-width: 48ch;
  font-size: clamp(15px, 1.6vw, 17px);
  line-height: 1.85;
  color: var(--paper-82);
}

.page-about .cover__facts {
  list-style: none;
  margin: 8px 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  max-width: 520px;
  background: rgba(245, 239, 228, 0.14);
  border: 1px solid var(--line-1);
}

.page-about .cover__facts li {
  display: grid;
  gap: 5px;
  padding: 14px 16px;
  background: var(--ink-2);
}

.page-about .cover__k {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  color: var(--slate);
}

.page-about .cover__v {
  font-family: var(--font-mono);
  font-size: 21px;
  line-height: 1;
  color: var(--paper);
}

/* ---------- 主体：索引轨道 + 内容流 ---------- */
.page-about .about-body {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--about-gap);
  padding-block: clamp(32px, 5vw, 64px) 0;
}

.page-about .about-index {
  display: none;
}

.page-about .about-index__label {
  margin: 0 0 14px;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--line-1);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.24em;
  text-transform: uppercase;
  color: var(--cyan);
}

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

.page-about .about-index__list a {
  display: flex;
  align-items: baseline;
  gap: 12px;
  padding: 9px 10px;
  border-left: 2px solid transparent;
  font-size: 14px;
  line-height: 1.5;
  color: var(--paper-70);
  text-decoration: none;
  transition: color 0.2s ease, border-color 0.2s ease, background 0.2s ease;
}

.page-about .about-index__list a span {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--slate);
  transition: color 0.2s ease;
}

.page-about .about-index__list a:hover,
.page-about .about-index__list a:focus-visible {
  color: var(--paper);
  border-left-color: var(--magenta);
  background: rgba(255, 61, 141, 0.08);
  outline: none;
}

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

.page-about .about-index__foot {
  margin: 22px 0 0;
  padding-top: 14px;
  border-top: 1px solid var(--line-1);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  color: var(--slate);
}

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

/* ---------- 章节 ---------- */
.page-about .ab-section {
  padding-block: clamp(30px, 5vw, 64px);
  border-top: 1px solid var(--line-1);
  scroll-margin-top: calc(var(--topbar-h) + 24px);
}

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

.page-about .ab-section .section-head {
  margin-bottom: clamp(22px, 3.4vw, 38px);
}

.page-about .section-title {
  max-width: 22ch;
}

.page-about .section-note {
  max-width: 60ch;
}

.page-about .ab-section p {
  max-width: 64ch;
  line-height: 1.8;
}

/* ---------- 时间线 ---------- */
.page-about .timeline {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  counter-reset: node;
  max-width: 70ch;
}

.page-about .timeline__item {
  position: relative;
  padding: 0 0 clamp(28px, 4.4vw, 46px) clamp(28px, 4vw, 46px);
}

.page-about .timeline__item::before {
  content: "";
  position: absolute;
  left: 0;
  top: 12px;
  bottom: 0;
  width: 1px;
  background: var(--line-1);
}

.page-about .timeline__item::after {
  content: "";
  position: absolute;
  left: -4px;
  top: 12px;
  width: 9px;
  height: 9px;
  background: var(--gold);
  transform: rotate(45deg);
  box-shadow: 0 0 0 4px var(--ink);
}

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

.page-about .timeline__item:last-child::before {
  display: none;
}

.page-about .timeline__no {
  display: inline-block;
  margin-bottom: 8px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.2em;
  color: var(--gold);
}

.page-about .timeline__stage {
  margin: 0 0 10px;
  font-family: var(--font-display);
  font-size: clamp(20px, 2.6vw, 26px);
  font-weight: 700;
  letter-spacing: 0.1em;
  color: var(--paper);
}

.page-about .timeline__text {
  margin: 0;
  font-size: 15.5px;
  line-height: 1.85;
  color: var(--paper-70);
}

/* ---------- 内容中心 ---------- */
.page-about .center-grid {
  display: grid;
  gap: clamp(20px, 3vw, 34px);
}

.page-about .center-grid__text {
  display: grid;
  gap: 14px;
}

.page-about .center-grid__text p {
  margin: 0;
  font-size: 15.5px;
  line-height: 1.85;
  color: var(--paper-70);
}

.page-about .center-grid__text p:first-child {
  color: var(--paper-82);
}

.page-about .center-grid .figure {
  margin: 0;
}

.page-about .center-facts {
  list-style: none;
  margin: clamp(22px, 3.4vw, 36px) 0 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: rgba(245, 239, 228, 0.12);
  border: 1px solid var(--line-1);
}

.page-about .center-facts li {
  display: grid;
  gap: 8px;
  padding: 16px 18px;
  background: var(--ink-2);
}

.page-about .fact__k {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  color: var(--cyan);
}

.page-about .fact__d {
  margin: 0;
  font-size: 14px;
  line-height: 1.7;
  color: var(--paper-70);
}

/* ---------- 团队 ---------- */
.page-about .team-grid {
  display: grid;
  gap: clamp(20px, 3vw, 32px);
}

.page-about .roles {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: clamp(12px, 2vw, 18px);
}

.page-about .role {
  display: grid;
  gap: 10px;
  padding: 18px 20px;
  border: 1px solid var(--line-1);
  border-left: 2px solid var(--stone);
  background: rgba(18, 27, 63, 0.6);
  transition: border-color 0.2s ease, background 0.2s ease;
}

.page-about .role:hover {
  border-left-color: var(--cyan);
  background: rgba(53, 240, 220, 0.06);
}

.page-about .role__head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 12px;
}

.page-about .role__tag {
  font-family: var(--font-display);
  font-size: 16px;
  font-weight: 700;
  letter-spacing: 0.12em;
  color: var(--paper);
}

.page-about .role__num {
  font-family: var(--font-mono);
  font-size: 18px;
  color: var(--gold);
}

.page-about .role__desc {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.78;
  color: var(--paper-70);
}

.page-about .team-figure {
  margin: 0;
}

.page-about .team-foot {
  margin: clamp(20px, 3vw, 30px) 0 0;
  padding: 16px 18px;
  border-left: 2px solid var(--clay);
  background: rgba(181, 106, 76, 0.08);
  font-size: 14.5px;
  line-height: 1.8;
  color: var(--paper-82);
}

/* ---------- 服务方式 ---------- */
.page-about .values {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: rgba(245, 239, 228, 0.12);
  border: 1px solid var(--line-1);
}

.page-about .values__item {
  display: grid;
  gap: 10px;
  align-content: start;
  padding: clamp(20px, 3vw, 30px);
  background: var(--ink-2);
  border-left: 2px solid transparent;
  transition: border-color 0.2s ease, background 0.2s ease;
}

.page-about .values__item:hover {
  border-left-color: var(--magenta);
  background: var(--ink);
}

.page-about .values__k {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.2em;
  color: var(--magenta);
}

.page-about .values__h {
  margin: 0;
  font-family: var(--font-display);
  font-size: 19px;
  font-weight: 700;
  letter-spacing: 0.09em;
  color: var(--paper);
}

.page-about .values__p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.8;
  color: var(--paper-70);
}

/* ---------- 下一步 ---------- */
.page-about .ab-next {
  border-top: 1px solid var(--line-1);
}

.page-about .next-panel {
  padding: clamp(22px, 4vw, 42px);
  border: 1px solid var(--line-1);
  background:
    radial-gradient(circle at 88% 10%, rgba(255, 61, 141, 0.16), transparent 58%),
    radial-gradient(circle at 6% 94%, rgba(53, 240, 220, 0.13), transparent 56%),
    var(--ink-2);
}

.page-about .next-panel .section-title {
  margin-bottom: clamp(18px, 3vw, 28px);
}

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

.page-about .next-links a {
  display: grid;
  gap: 6px;
  padding: 16px 18px;
  border: 1px solid var(--line-1);
  background: rgba(11, 16, 38, 0.62);
  text-decoration: none;
  transition: border-color 0.2s ease, background 0.2s ease;
}

.page-about .next-links a:hover,
.page-about .next-links a:focus-visible {
  border-color: var(--cyan);
  background: rgba(53, 240, 220, 0.07);
  outline: none;
}

.page-about .next-links strong {
  font-family: var(--font-display);
  font-size: 15px;
  font-weight: 700;
  letter-spacing: 0.06em;
  color: var(--paper);
}

.page-about .next-links span {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.04em;
  line-height: 1.6;
  color: var(--slate);
}

.page-about .next-links a:hover span,
.page-about .next-links a:focus-visible span {
  color: var(--paper-70);
}

/* ---------- 响应式 ---------- */
@media (min-width: 620px) {
  .page-about .cover__facts {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    max-width: 640px;
  }

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

@media (min-width: 780px) {
  .page-about .center-grid {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1.05fr);
    align-items: start;
  }

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

@media (min-width: 860px) {
  .page-about .team-grid {
    grid-template-columns: minmax(0, 1.4fr) minmax(0, 0.85fr);
    align-items: start;
  }

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

@media (min-width: 960px) {
  .page-about .about-body {
    grid-template-columns: var(--about-rail) minmax(0, 1fr);
    gap: clamp(32px, 4vw, 60px);
  }

  .page-about .about-index {
    display: block;
    position: sticky;
    top: calc(var(--topbar-h) + 28px);
    align-self: start;
  }

  .page-about .role:nth-child(even) {
    transform: translateX(clamp(0px, 2.2vw, 26px));
  }

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

@media (prefers-reduced-motion: reduce) {
  .page-about .about-index__list a,
  .page-about .values__item,
  .page-about .role,
  .page-about .next-links a {
    transition: none;
  }

  .page-about .role:nth-child(even) {
    transform: none;
  }
}