.page-about {
  --about-hair: rgba(168, 243, 228, 0.16);
  --about-body: rgba(234, 243, 240, 0.82);
}

/* ===== 面包屑 ===== */
.page-about .breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  padding-top: 16px;
  padding-bottom: 4px;
  font-size: 13px;
  letter-spacing: 0.04em;
  color: var(--muted);
}

.page-about .breadcrumb a {
  color: var(--cyan-soft);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: border-color 0.2s ease;
}

.page-about .breadcrumb a:hover,
.page-about .breadcrumb a:focus-visible {
  border-bottom-color: var(--cyan);
}

/* ===== 首屏 ===== */
.page-about .about-hero {
  padding-top: clamp(14px, 2.4vw, 26px);
}

.page-about .about-hero__grid {
  display: grid;
  gap: clamp(26px, 5vw, 48px);
}

.page-about .about-hero__title {
  font-family: var(--font-display);
  font-size: clamp(31px, 6.6vw, 62px);
  line-height: 1.12;
  letter-spacing: 0.05em;
  margin: 14px 0 0;
  color: var(--paper);
}

.page-about .about-hero__lede {
  margin-top: 20px;
  max-width: 62ch;
  font-size: clamp(16px, 1.6vw, 18px);
  line-height: 1.85;
  color: var(--about-body);
}

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

.page-about .about-hero__aside {
  display: grid;
  gap: 18px;
  align-content: start;
}

.page-about .about-hero__note {
  font-size: 12px;
  letter-spacing: 0.2em;
  color: var(--muted);
  text-transform: uppercase;
}

.page-about .about-stats {
  margin: 0;
  display: grid;
  gap: 0;
  border-top: 1px solid var(--about-hair);
}

.page-about .about-stats > div {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 16px;
  padding: 13px 0;
  border-bottom: 1px solid var(--about-hair);
}

.page-about .about-stats dt {
  font-size: 13px;
  letter-spacing: 0.05em;
  color: var(--muted);
}

.page-about .about-stats dd {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 20px;
  letter-spacing: 0.02em;
  color: var(--cyan);
  font-variant-numeric: tabular-nums;
}

@media (min-width: 900px) {
  .page-about .about-hero__grid {
    grid-template-columns: repeat(12, minmax(0, 1fr));
    align-items: start;
  }

  .page-about .about-hero__lead {
    grid-column: 1 / span 7;
  }

  .page-about .about-hero__aside {
    grid-column: 9 / span 4;
    grid-template-columns: auto minmax(0, 1fr);
    gap: 20px;
    align-items: start;
  }

  .page-about .about-hero__note {
    writing-mode: vertical-rl;
    letter-spacing: 0.34em;
    max-height: 240px;
  }
}

/* ===== 区块标题 ===== */
.page-about .about-head {
  max-width: 62rem;
  margin-bottom: clamp(22px, 3.2vw, 40px);
}

.page-about .about-head .h2 {
  margin-top: 12px;
  letter-spacing: 0.05em;
  font-size: clamp(24px, 3.6vw, 40px);
  line-height: 1.24;
}

.page-about .about-head__note {
  margin-top: 14px;
  max-width: 56ch;
  font-size: 15.5px;
  line-height: 1.85;
  color: var(--muted);
}

@media (min-width: 900px) {
  .page-about .about-head--split {
    max-width: none;
    display: grid;
    grid-template-columns: minmax(0, 7fr) minmax(0, 4fr);
    gap: clamp(20px, 4vw, 60px);
    align-items: end;
  }

  .page-about .about-head--split .about-head__note {
    margin-top: 0;
  }
}

/* ===== 图框微调 ===== */
.page-about .about-phases__figure,
.page-about .about-team__figure,
.page-about .about-archive__figure {
  margin: 0 0 clamp(24px, 3.6vw, 42px);
}

.page-about .about-team__figure {
  border-radius: var(--radius-xl);
}

/* ===== 时间轴 ===== */
.page-about .timeline {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: clamp(22px, 3vw, 30px);
}

.page-about .timeline__item {
  position: relative;
}

.page-about .timeline__node {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 46px;
  height: 46px;
  border-radius: var(--radius-pill);
  border: 1px solid rgba(79, 224, 192, 0.5);
  background: var(--ink);
  color: var(--cyan);
  font-size: 13px;
  letter-spacing: 0.06em;
}

.page-about .phase-panel {
  margin-top: 14px;
  background: var(--panel);
  border: 1px solid var(--about-hair);
  border-radius: var(--radius-lg);
  overflow: hidden;
  transition: background-color 0.25s ease, border-color 0.25s ease;
}

.page-about .phase-panel[open] {
  background: var(--panel-lift);
  border-color: rgba(79, 224, 192, 0.34);
}

.page-about .phase-panel__head {
  display: flex;
  align-items: baseline;
  gap: 10px;
  padding: 18px 20px 16px;
  cursor: pointer;
  list-style: none;
  user-select: none;
}

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

.page-about .phase-panel__head::after {
  content: "+";
  margin-left: 12px;
  font-family: var(--font-mono);
  font-size: 18px;
  line-height: 1;
  color: var(--cyan);
  transition: transform 0.25s ease;
}

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

.page-about .phase-panel__name {
  font-family: var(--font-display);
  font-size: 19px;
  letter-spacing: 0.07em;
  color: var(--paper);
}

.page-about .phase-panel__mark {
  margin-left: auto;
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--cyan-soft);
}

.page-about .phase-panel__body {
  padding: 0 20px 22px;
}

.page-about .phase-panel__body p {
  margin: 0;
  font-size: 15.5px;
  line-height: 1.85;
  color: var(--about-body);
}

.page-about .phase-panel__body p a {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(79, 224, 192, 0.4);
}

.page-about .phase-panel__body p a:hover,
.page-about .phase-panel__body p a:focus-visible {
  border-bottom-color: var(--cyan);
}

.page-about .phase-facts {
  list-style: none;
  margin: 16px 0 0;
  padding: 0;
  display: grid;
  gap: 9px;
}

.page-about .phase-facts li {
  display: grid;
  grid-template-columns: 14px minmax(0, 1fr);
  gap: 10px;
  font-size: 14.5px;
  line-height: 1.7;
  color: var(--muted);
}

.page-about .phase-facts li::before {
  content: "";
  width: 6px;
  height: 6px;
  margin-top: 9px;
  border-radius: 2px;
  background: var(--cyan);
}

@media (min-width: 860px) {
  .page-about .timeline {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: clamp(18px, 2.2vw, 28px);
  }

  .page-about .timeline::before {
    content: "";
    position: absolute;
    top: 23px;
    left: 0;
    right: 0;
    height: 1px;
    background: linear-gradient(90deg, rgba(79, 224, 192, 0.5), rgba(79, 224, 192, 0.08));
  }

  .page-about .timeline__item {
    z-index: 1;
  }

  .page-about .timeline__item:nth-child(2) {
    margin-top: 30px;
  }

  .page-about .timeline__item:nth-child(3) {
    margin-top: 60px;
  }
}

/* ===== 团队名册 ===== */
.page-about .team-roster {
  border-top: 1px solid var(--about-hair);
}

.page-about .team-row {
  display: grid;
  gap: 8px;
  padding: clamp(18px, 2.4vw, 26px) 0;
  border-bottom: 1px solid var(--about-hair);
}

.page-about .team-row__name {
  margin: 0;
  font-family: var(--font-display);
  font-size: 18px;
  letter-spacing: 0.06em;
  color: var(--cyan-soft);
}

.page-about .team-row__desc {
  margin: 0;
  font-size: 15.5px;
  line-height: 1.85;
  color: var(--about-body);
}

@media (min-width: 820px) {
  .page-about .team-row {
    grid-template-columns: minmax(0, 200px) minmax(0, 1fr);
    gap: clamp(18px, 3vw, 46px);
    align-items: baseline;
  }
}

/* ===== 双栏档案 ===== */
.page-about .archive-split {
  display: grid;
  gap: 22px;
}

.page-about .archive-col {
  padding: clamp(22px, 3vw, 34px);
  border: 1px solid var(--about-hair);
  border-radius: var(--radius-xl);
  background: var(--panel);
}

.page-about .archive-col--youth {
  background: var(--panel-lift);
}

.page-about .archive-col__label {
  font-size: 11px;
  letter-spacing: 0.26em;
  color: var(--muted);
}

.page-about .archive-col__title {
  margin: 10px 0 0;
  font-family: var(--font-display);
  font-size: clamp(20px, 2.6vw, 26px);
  letter-spacing: 0.06em;
  color: var(--paper);
}

.page-about .archive-col__count {
  margin: 10px 0 0;
  font-family: var(--font-mono);
  font-size: 26px;
  letter-spacing: 0.02em;
  color: var(--cyan);
  font-variant-numeric: tabular-nums;
}

.page-about .archive-col__intro {
  margin: 14px 0 0;
  font-size: 15.5px;
  line-height: 1.85;
  color: var(--about-body);
}

.page-about .archive-fields {
  margin: 22px 0 0;
  border-top: 1px solid var(--about-hair);
}

.page-about .archive-fields > div {
  padding: 14px 0;
  border-bottom: 1px solid var(--about-hair);
}

.page-about .archive-fields dt {
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.06em;
  color: var(--cyan-soft);
}

.page-about .archive-fields dd {
  margin: 6px 0 0;
  font-size: 14.5px;
  line-height: 1.75;
  color: var(--muted);
}

@media (min-width: 880px) {
  .page-about .archive-split {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: clamp(22px, 3vw, 38px);
    align-items: start;
  }

  .page-about .archive-col--youth {
    margin-top: 62px;
  }
}

/* ===== 收录与发布 ===== */
.page-about .standard-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: clamp(16px, 2.2vw, 24px);
}

.page-about .standard-item {
  display: grid;
  grid-template-columns: 44px minmax(0, 1fr);
  gap: 16px;
  padding: clamp(18px, 2.4vw, 26px) 0;
  border-bottom: 1px solid var(--about-hair);
}

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

.page-about .standard-item__idx {
  font-size: 13px;
  letter-spacing: 0.06em;
  color: var(--cyan);
  padding-top: 4px;
}

.page-about .standard-item .h3 {
  margin: 0;
  font-family: var(--font-display);
  font-size: 19px;
  letter-spacing: 0.05em;
  color: var(--paper);
}

.page-about .standard-item p {
  margin: 10px 0 0;
  max-width: 72ch;
  font-size: 15.5px;
  line-height: 1.85;
  color: var(--about-body);
}

/* ===== 合作与服务 ===== */
.page-about .coop-list {
  display: grid;
  gap: 16px;
}

.page-about .coop-item {
  padding: clamp(20px, 2.6vw, 28px);
  border-radius: var(--radius-lg);
  border: 1px solid var(--about-hair);
  background: var(--veil);
  border-left: 3px solid rgba(79, 224, 192, 0.55);
}

.page-about .coop-item__title {
  margin: 0;
  font-family: var(--font-display);
  font-size: 18px;
  letter-spacing: 0.06em;
  color: var(--paper);
}

.page-about .coop-item__desc {
  margin: 12px 0 0;
  font-size: 15px;
  line-height: 1.85;
  color: var(--about-body);
}

.page-about .coop-item__tag {
  margin: 16px 0 0;
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--cyan-soft);
}

.page-about .coop-cta {
  margin-top: clamp(24px, 3.4vw, 38px);
  padding: clamp(20px, 2.8vw, 30px);
  border-radius: var(--radius-lg);
  border: 1px solid rgba(79, 224, 192, 0.3);
  background: var(--panel-lift);
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}

.page-about .coop-cta__text {
  margin: 0;
  font-size: 15.5px;
  line-height: 1.7;
  color: var(--paper);
}

@media (min-width: 860px) {
  .page-about .coop-list {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: clamp(16px, 2vw, 24px);
  }
}

/* ===== 落款 ===== */
.page-about .about-signoff {
  padding: clamp(26px, 3.4vw, 44px) 0 clamp(10px, 1.6vw, 18px);
}

.page-about .about-signoff__line {
  margin: 0;
  font-size: 12px;
  line-height: 1.9;
  letter-spacing: 0.04em;
  color: var(--muted);
}

/* ===== 窄屏兜底 ===== */
@media (max-width: 560px) {
  .page-about .standard-item {
    grid-template-columns: minmax(0, 1fr);
    gap: 8px;
  }

  .page-about .standard-item__idx {
    padding-top: 0;
  }

  .page-about .about-stats dd {
    font-size: 18px;
  }

  .page-about .archive-col__count {
    font-size: 22px;
  }
}