.page-about {
  --about-gap: clamp(24px, 4vw, 56px);
  --about-chapter-pad: clamp(48px, 8vw, 104px);
  position: relative;
  overflow-x: clip;
}

.page-about .about-link {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(56, 242, 210, .35);
  transition: border-color var(--dur) var(--ease), color var(--dur) var(--ease);
}

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

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  padding: clamp(44px, 8vw, 96px) 0 clamp(40px, 6vw, 72px);
  background:
    radial-gradient(120% 92% at 90% 4%, rgba(56, 242, 210, .11), transparent 58%),
    radial-gradient(96% 74% at 4% 96%, rgba(255, 107, 44, .09), transparent 62%);
}

.page-about .about-hero-inner {
  display: grid;
  gap: var(--about-gap);
}

.page-about .about-hero-rail {
  display: flex;
  align-items: center;
  gap: 14px;
  flex-wrap: wrap;
}

.page-about .about-hero-rail-line {
  flex: 1 1 60px;
  min-width: 40px;
  height: 1px;
  background: var(--hair-strong);
}

.page-about .about-hero-kicker {
  color: var(--cyan);
}

.page-about .about-hero-rail-note {
  color: var(--mist);
}

.page-about .about-hero-title {
  margin: 0 0 clamp(18px, 3vw, 28px);
  font-size: clamp(38px, 8.6vw, 92px);
  line-height: .98;
  letter-spacing: .01em;
  color: var(--star);
}

.page-about .about-hero-lede {
  margin: 0;
  max-width: 52ch;
  font-size: var(--fs-16);
  line-height: 1.9;
  color: var(--mist);
}

.page-about .about-hero-lede::first-line {
  color: var(--star);
}

.page-about .about-hero-facts {
  list-style: none;
  margin: clamp(30px, 5vw, 48px) 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--hair);
  border-top: 1px solid var(--hair);
  border-bottom: 1px solid var(--hair);
}

.page-about .about-fact {
  background: rgba(18, 39, 72, .45);
  padding: 18px 16px;
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.page-about .about-fact-num {
  font-size: clamp(30px, 7vw, 46px);
  line-height: 1;
  color: var(--star);
}

.page-about .about-fact:nth-child(2) .about-fact-num {
  color: var(--cyan);
}

.page-about .about-fact:nth-child(3) .about-fact-num {
  color: var(--sand);
}

.page-about .about-fact:nth-child(4) .about-fact-num {
  color: var(--grass);
}

.page-about .about-fact-label {
  font-size: var(--fs-12);
  letter-spacing: .12em;
  color: var(--mist);
}

/* ---------- 章节通用 ---------- */
.page-about .about-chapter {
  padding: var(--about-chapter-pad) 0;
  border-top: 1px solid var(--hair);
  position: relative;
}

.page-about .about-chapter-grid {
  display: grid;
  gap: clamp(20px, 3.6vw, 40px);
}

.page-about .about-chapter-head {
  display: grid;
  grid-template-columns: auto 1fr;
  align-items: baseline;
  gap: 12px 16px;
  align-content: start;
}

.page-about .about-chapter-num {
  font-size: clamp(28px, 5vw, 44px);
  line-height: 1;
  color: var(--orange);
}

.page-about .about-chapter-title {
  margin: 0;
  font-size: clamp(26px, 5.6vw, 46px);
  line-height: 1.06;
  color: var(--star);
}

.page-about .about-chapter-tag {
  grid-column: 2;
  font-family: var(--font-num);
  font-size: var(--fs-12);
  letter-spacing: .18em;
  text-transform: uppercase;
  color: var(--mist);
  border: 1px solid var(--hair);
  padding: 3px 9px;
  justify-self: start;
}

.page-about .about-chapter-body > * + * {
  margin-top: 20px;
}

.page-about .about-lead {
  margin: 0;
  font-size: var(--fs-20);
  line-height: 1.85;
  color: var(--star);
  font-weight: 500;
}

.page-about .about-chapter-body p {
  color: var(--mist);
  line-height: 1.9;
}

.page-about .about-sub-title {
  margin: 34px 0 0;
  font-family: var(--font-display);
  font-size: var(--fs-20);
  letter-spacing: .02em;
  color: var(--star);
}

.page-about .about-aside {
  margin-top: 26px;
  padding-left: 18px;
  border-left: 2px solid var(--blue-600);
  font-size: var(--fs-14);
  line-height: 1.85;
  color: var(--mist);
}

.page-about .about-aside .about-link {
  margin: 0 2px;
}

/* ---------- 01 核心价值 ---------- */
.page-about .about-values {
  list-style: none;
  margin: 30px 0 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--hair);
}

.page-about .about-value {
  background: var(--sky-900);
  padding: 22px 0 22px 18px;
  border-left: 2px solid var(--hair-strong);
  display: grid;
  gap: 8px;
  transition: border-color var(--dur) var(--ease), background var(--dur) var(--ease);
}

.page-about .about-value:hover {
  border-left-color: var(--cyan);
  background: rgba(18, 39, 72, .6);
}

.page-about .about-value-key {
  font-family: var(--font-num);
  font-size: var(--fs-12);
  letter-spacing: .18em;
  color: var(--sand);
}

.page-about .about-value p {
  margin: 0;
  font-size: var(--fs-16);
  color: var(--mist);
}

/* ---------- 02 时间线 ---------- */
.page-about .about-timeline {
  list-style: none;
  margin: 34px 0 0;
  padding: 0;
}

.page-about .about-timeline-item {
  position: relative;
  padding: 0 0 36px 30px;
  border-left: 1px solid var(--hair-strong);
}

.page-about .about-timeline-item:last-child {
  padding-bottom: 0;
  border-left-color: transparent;
}

.page-about .about-timeline-item::before {
  content: "";
  position: absolute;
  left: -5px;
  top: 8px;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--sky-900);
  border: 1px solid var(--mist);
  transition: border-color var(--dur) var(--ease), background var(--dur) var(--ease);
}

.page-about .about-timeline-item:hover::before,
.page-about .about-timeline-item:focus-within::before {
  border-color: var(--cyan);
  background: var(--cyan);
}

.page-about .about-timeline-marker {
  display: flex;
  align-items: baseline;
  gap: 12px;
}

.page-about .about-timeline-year {
  font-size: clamp(28px, 6vw, 42px);
  line-height: 1;
  color: var(--cyan);
}

.page-about .about-timeline-ver {
  font-family: var(--font-num);
  font-size: var(--fs-12);
  letter-spacing: .18em;
  text-transform: uppercase;
  color: var(--mist);
  border: 1px solid var(--hair);
  padding: 2px 8px;
}

.page-about .about-timeline-title {
  margin: 12px 0 8px;
  font-family: var(--font-display);
  font-size: var(--fs-20);
  line-height: 1.4;
  letter-spacing: .02em;
  color: var(--star);
}

.page-about .about-timeline-item p {
  margin: 0 0 8px;
  font-size: var(--fs-14);
  color: var(--mist);
}

.page-about .about-timeline-more {
  font-family: var(--font-num);
  font-size: var(--fs-12);
  letter-spacing: .04em;
  color: var(--blue-600);
  filter: brightness(1.7);
}

/* ---------- 03 青训 ---------- */
.page-about .about-chapter--youth {
  background:
    radial-gradient(80% 60% at 100% 0%, rgba(47, 163, 107, .08), transparent 60%),
    var(--sky-900);
}

.page-about .about-youth-head {
  display: grid;
  grid-template-columns: auto 1fr;
  align-items: baseline;
  gap: 12px 16px;
  margin-bottom: clamp(28px, 5vw, 52px);
}

.page-about .about-youth-head .about-chapter-title {
  grid-column: 2;
}

.page-about .about-youth-head .about-chapter-tag {
  grid-column: 2;
}

.page-about .about-youth-grid {
  display: grid;
  gap: clamp(28px, 5vw, 56px);
}

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

.page-about .about-youth-frame img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.page-about .about-youth-figure .media-caption {
  display: block;
  margin-top: 12px;
  font-size: var(--fs-12);
  line-height: 1.7;
  color: var(--mist);
}

.page-about .about-youth-text > * + * {
  margin-top: 20px;
}

.page-about .about-youth-text p {
  color: var(--mist);
  line-height: 1.95;
}

.page-about .about-age-list {
  margin-top: 30px;
  border-top: 1px solid var(--hair);
}

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

.page-about .about-age > summary,
.page-about .about-partner > summary {
  cursor: pointer;
  list-style: none;
  display: flex;
  align-items: baseline;
  gap: 14px;
  padding: 16px 0;
  transition: color var(--dur) var(--ease);
}

.page-about .about-age > summary::-webkit-details-marker,
.page-about .about-partner > summary::-webkit-details-marker {
  display: none;
}

.page-about .about-age > summary:hover,
.page-about .about-age > summary:focus-visible,
.page-about .about-partner > summary:hover,
.page-about .about-partner > summary:focus-visible {
  color: var(--cyan);
}

.page-about .about-age-code {
  font-size: var(--fs-16);
  letter-spacing: .06em;
  color: var(--cyan);
  min-width: 3.4em;
}

.page-about .about-age-name {
  flex: 1;
  font-family: var(--font-display);
  font-size: var(--fs-16);
  letter-spacing: .02em;
  color: var(--star);
}

.page-about .about-age-sign {
  position: relative;
  width: 12px;
  height: 12px;
  flex: 0 0 12px;
  align-self: center;
}

.page-about .about-age-sign::before,
.page-about .about-age-sign::after {
  content: "";
  position: absolute;
  background: var(--mist);
  transition: transform var(--dur) var(--ease), background var(--dur) var(--ease);
}

.page-about .about-age-sign::before {
  top: 5px;
  left: 0;
  width: 12px;
  height: 1px;
}

.page-about .about-age-sign::after {
  left: 5px;
  top: 0;
  width: 1px;
  height: 12px;
}

.page-about details[open] > summary .about-age-sign::after {
  transform: scaleY(0);
}

.page-about details[open] > summary .about-age-sign::before {
  background: var(--cyan);
}

.page-about .about-age p,
.page-about .about-partner p {
  margin: 0 0 18px;
  padding-left: 0;
  font-size: var(--fs-14);
  line-height: 1.9;
  color: var(--mist);
  max-width: 62ch;
}

/* ---------- 04 输送 ---------- */
.page-about .about-pipeline-lead {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 20px;
  align-items: center;
  padding: clamp(20px, 3vw, 30px) 0;
  border-top: 1px solid var(--hair);
  border-bottom: 1px solid var(--hair);
}

.page-about .about-pipeline-num {
  font-size: clamp(56px, 15vw, 112px);
  line-height: .86;
  color: var(--sand);
}

.page-about .about-pipeline-title {
  margin: 0 0 6px;
  font-size: var(--fs-16);
  line-height: 1.6;
  color: var(--star);
}

.page-about .about-pipeline-note {
  margin: 0;
  font-size: var(--fs-14);
  color: var(--mist);
}

.page-about .about-spec-list {
  list-style: none;
  margin: 22px 0 0;
  padding: 0;
}

.page-about .about-spec-list li {
  display: grid;
  gap: 6px;
  padding: 16px 0;
  border-bottom: 1px solid var(--hair);
}

.page-about .about-spec-key {
  color: var(--cyan);
}

.page-about .about-spec-val {
  font-size: var(--fs-14);
  line-height: 1.85;
  color: var(--mist);
}

/* ---------- 05 团队 ---------- */
.page-about .about-roles {
  margin-top: 30px;
  display: grid;
  gap: 1px;
  background: var(--hair);
  border: 1px solid var(--hair);
}

.page-about .about-role {
  background: var(--sky-900);
  padding: 22px 18px;
  display: grid;
  gap: 8px;
  transition: background var(--dur) var(--ease);
}

.page-about .about-role:hover {
  background: rgba(18, 39, 72, .72);
}

.page-about .about-role-count {
  font-size: clamp(30px, 7vw, 44px);
  line-height: 1;
  color: var(--cyan);
}

.page-about .about-role-name {
  margin: 0;
  font-family: var(--font-display);
  font-size: var(--fs-20);
  letter-spacing: .02em;
  color: var(--star);
}

.page-about .about-role p {
  margin: 0;
  font-size: var(--fs-14);
  line-height: 1.85;
  color: var(--mist);
}

/* ---------- 06 甘肃 ---------- */
.page-about .about-chapter--gansu {
  background:
    radial-gradient(90% 60% at 0% 100%, rgba(233, 196, 106, .07), transparent 62%);
}

.page-about .about-gansu-head {
  display: grid;
  grid-template-columns: auto 1fr;
  align-items: baseline;
  gap: 12px 16px;
  margin-bottom: clamp(24px, 4vw, 44px);
}

.page-about .about-gansu-head .about-chapter-title,
.page-about .about-gansu-head .about-chapter-tag {
  grid-column: 2;
}

.page-about .about-gansu-banner {
  margin-bottom: clamp(28px, 4vw, 48px);
}

.page-about .about-gansu-frame img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.page-about .about-gansu-caption {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 12px;
  margin-top: 14px;
}

.page-about .about-gansu-caption .index-label {
  color: var(--orange);
}

.page-about .about-gansu-caption p {
  margin: 0;
  flex: 1 1 260px;
  font-size: var(--fs-14);
  line-height: 1.8;
  color: var(--mist);
}

.page-about .about-gansu-grid {
  display: grid;
  gap: clamp(26px, 4vw, 48px);
}

.page-about .about-gansu-points {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--hair);
  border-top: 1px solid var(--hair);
  border-bottom: 1px solid var(--hair);
}

.page-about .about-gansu-points li {
  background: var(--sky-900);
  padding: 20px 0;
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 16px;
  align-items: start;
}

.page-about .about-point-num {
  font-size: clamp(26px, 5vw, 36px);
  line-height: 1;
  color: var(--grass);
}

.page-about .about-gansu-points p {
  margin: 0;
  font-size: var(--fs-14);
  line-height: 1.85;
  color: var(--mist);
}

/* ---------- 07 合作 ---------- */
.page-about .about-partners {
  margin-top: 28px;
  border-top: 1px solid var(--hair);
}

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

.page-about .about-partner-tag {
  color: var(--orange);
  min-width: 2.4em;
}

.page-about .about-partner-name {
  flex: 1;
  font-family: var(--font-display);
  font-size: var(--fs-20);
  letter-spacing: .02em;
  color: var(--star);
}

/* ---------- 页尾 ---------- */
.page-about .about-closing {
  position: relative;
  padding: clamp(48px, 8vw, 96px) 0 clamp(56px, 9vw, 110px);
  border-top: 1px solid var(--hair);
  background:
    radial-gradient(100% 80% at 12% 100%, rgba(255, 107, 44, .12), transparent 60%),
    radial-gradient(80% 60% at 92% 8%, rgba(56, 242, 210, .08), transparent 62%);
}

.page-about .about-closing-inner {
  display: grid;
  gap: clamp(26px, 4vw, 48px);
}

.page-about .about-closing-title {
  margin: 0 0 16px;
  font-size: clamp(28px, 6vw, 54px);
  line-height: 1.04;
  color: var(--star);
}

.page-about .about-closing-copy p {
  margin: 0 0 26px;
  max-width: 46ch;
  font-size: var(--fs-16);
  line-height: 1.9;
  color: var(--mist);
}

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

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

.page-about .about-closing-frame img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

/* ---------- 宽度适配 ---------- */
@media (min-width: 700px) {
  .page-about .about-hero-facts {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

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

  .page-about .about-youth-grid {
    grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
    align-items: start;
  }

  .page-about .about-gansu-grid {
    grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
  }

  .page-about .about-closing-inner {
    grid-template-columns: minmax(0, 6fr) minmax(0, 6fr);
    align-items: center;
  }
}

@media (min-width: 980px) {
  .page-about .about-chapter-grid {
    grid-template-columns: minmax(0, 4fr) minmax(0, 8fr);
    gap: clamp(32px, 4vw, 64px);
  }

  .page-about .about-chapter-head {
    position: sticky;
    top: 108px;
  }

  .page-about .about-chapter--youth .about-youth-grid {
    grid-template-columns: minmax(0, 4fr) minmax(0, 7fr);
    gap: clamp(36px, 5vw, 72px);
  }

  .page-about .about-hero-inner {
    grid-template-columns: minmax(0, 2fr) minmax(0, 10fr);
    align-items: start;
  }

  .page-about .about-hero-rail {
    flex-direction: column;
    align-items: flex-start;
    gap: 16px;
    padding-top: 12px;
  }

  .page-about .about-hero-rail-line {
    flex: 0 0 auto;
    width: 1px;
    height: 96px;
    min-width: 0;
  }

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

  .page-about .about-hero-facts {
    margin-top: clamp(40px, 6vw, 64px);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-value,
  .page-about .about-role,
  .page-about .about-age-sign::before,
  .page-about .about-age-sign::after,
  .page-about .about-timeline-item::before,
  .page-about .about-link {
    transition: none;
  }
}