.page-about {
  --about-pad: clamp(46px, 7vw, 92px);
  --about-rule: var(--ink-grid);
  display: block;
}

/* ---------- 面包屑 ---------- */
.page-about .about-crumb {
  padding-top: 20px;
  padding-bottom: 4px;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  padding: 26px 0 var(--about-pad);
  background: radial-gradient(120% 92% at 12% 0%, rgba(47, 127, 209, 0.20) 0%, rgba(11, 27, 51, 0) 62%);
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 3px;
  background: linear-gradient(90deg,
    var(--flag-blue) 0 20%,
    var(--flag-white) 20% 40%,
    var(--flag-red) 40% 60%,
    var(--flag-green) 60% 80%,
    var(--flag-yellow) 80% 100%);
}

.page-about .about-hero__inner {
  display: grid;
  gap: 34px;
}

.page-about .about-hero__eyebrow {
  margin: 0 0 14px;
  font-size: 12px;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--flag-yellow);
}

.page-about .about-hero h1 {
  margin: 0 0 18px;
  max-width: 17em;
  font-family: var(--font-display);
  font-size: clamp(30px, 6.4vw, 54px);
  line-height: 1.2;
  letter-spacing: 0.02em;
  color: var(--text-strong);
}

.page-about .about-hero__lead {
  margin: 0;
  max-width: 36em;
  font-size: 17px;
  line-height: 1.95;
  color: var(--text-body);
}

.page-about .about-hero__facts {
  list-style: none;
  margin: 0;
  padding: 0;
  border-left: var(--stroke-fat) solid var(--amber);
}

.page-about .about-hero__facts li {
  display: flex;
  align-items: baseline;
  flex-wrap: wrap;
  gap: 12px;
  padding: 13px 0 13px 18px;
  border-bottom: 1px solid var(--about-rule);
}

.page-about .about-hero__facts li:last-child {
  border-bottom: 0;
}

.page-about .stat .stat__value {
  font-size: 1.5em;
  color: var(--flag-yellow);
  line-height: 1;
}

.page-about .stat .stat__unit {
  margin-left: 5px;
  font-size: 0.72em;
  color: var(--text-mute);
}

.page-about .about-hero__fact-label {
  flex: 1 1 auto;
  min-width: 0;
  font-size: 13px;
  line-height: 1.6;
  color: var(--text-mute);
}

/* ---------- 通用分节 ---------- */
.page-about .about-section {
  padding: var(--about-pad) 0;
  border-top: var(--stroke) solid var(--about-rule);
}

.page-about .section-head__eyebrow {
  margin: 0 0 8px;
  font-size: 12px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--flag-blue);
}

.page-about .section-head__title {
  margin: 0;
  max-width: 20em;
  font-family: var(--font-display);
  font-size: clamp(23px, 3.6vw, 34px);
  line-height: 1.3;
  letter-spacing: 0.03em;
  color: var(--text-strong);
}

.page-about .about-lead {
  margin: 18px 0 0;
  max-width: 42em;
  font-size: 16px;
  line-height: 1.95;
  color: var(--text-body);
}

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

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

.page-about .btn {
  display: inline-block;
  text-decoration: none;
}

/* ---------- 媒体框 ---------- */
.page-about .media-frame {
  position: relative;
  margin: 0;
  overflow: hidden;
  border: var(--stroke) solid var(--about-rule);
  background: var(--ink-archive);
  box-shadow: var(--hard-shadow-sm);
}

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

.page-about .media-frame__caption {
  display: block;
  padding: 10px 14px;
  border-top: var(--stroke) solid var(--about-rule);
  background: var(--ink-void);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--text-mute);
}

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

.page-about .timeline__item {
  position: relative;
  padding: 0 0 26px 30px;
  border-left: var(--stroke) solid var(--about-rule);
}

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

.page-about .timeline__item::before {
  content: "";
  position: absolute;
  left: -8px;
  top: 24px;
  width: 11px;
  height: 11px;
  background: var(--flag-blue);
  border: var(--stroke) solid var(--ink-void);
}

.page-about .timeline__item[data-tone="green"]::before { background: var(--flag-green); }
.page-about .timeline__item[data-tone="yellow"]::before { background: var(--flag-yellow); }
.page-about .timeline__item[data-tone="amber"]::before { background: var(--amber); }

/* ---------- 可展开节点 ---------- */
.page-about .node {
  border: var(--stroke) solid var(--about-rule);
  background: var(--ink-archive);
  transition: border-color 0.18s ease, box-shadow 0.18s ease;
}

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

.page-about .node[open] {
  border-color: var(--flag-blue);
  box-shadow: var(--hard-shadow-sm);
}

.page-about .node > summary {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr) auto;
  align-items: center;
  gap: 14px;
  padding: 16px 18px;
  cursor: pointer;
  list-style: none;
}

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

.page-about .node__phase {
  padding: 3px 8px;
  border: 1px solid var(--about-rule);
  font-size: 11.5px;
  letter-spacing: 0.12em;
  color: var(--flag-yellow);
  white-space: nowrap;
}

.page-about .node__title {
  min-width: 0;
  font-family: var(--font-display);
  font-size: 17px;
  line-height: 1.5;
  letter-spacing: 0.04em;
  color: var(--text-strong);
}

.page-about .node > summary::after {
  content: "＋";
  font-family: var(--font-index);
  font-size: 15px;
  color: var(--text-mute);
}

.page-about .node[open] > summary::after {
  content: "－";
  color: var(--amber);
}

.page-about .node__body {
  padding: 16px 18px 20px;
  border-top: 1px solid var(--about-rule);
}

.page-about .node__body p {
  margin: 0 0 14px;
  max-width: 40em;
  font-size: 15px;
  line-height: 1.9;
  color: var(--text-body);
}

.page-about .node__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 8px;
}

.page-about .node__list li {
  position: relative;
  padding-left: 18px;
  font-size: 14.5px;
  line-height: 1.8;
  color: var(--text-mute);
}

.page-about .node__list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 10px;
  width: 8px;
  height: 3px;
  background: var(--flag-blue);
}

/* ---------- 团队 ---------- */
.page-about .about-team__figure {
  margin-top: 30px;
}

.page-about .team-grid {
  display: grid;
  gap: 20px;
  margin-top: 30px;
}

.page-about .team-card {
  padding: 24px 22px;
  border: var(--stroke) solid var(--about-rule);
  background: var(--ink-archive);
  box-shadow: var(--hard-shadow-sm);
  transition: border-color 0.2s ease;
}

.page-about .team-card:hover,
.page-about .team-card:focus-within {
  border-color: var(--amber);
}

.page-about .team-card__index {
  margin: 0;
  font-size: 11.5px;
  letter-spacing: 0.18em;
  color: var(--flag-yellow);
}

.page-about .team-card h3 {
  margin: 10px 0 10px;
  font-family: var(--font-display);
  font-size: 21px;
  letter-spacing: 0.05em;
  color: var(--text-strong);
}

.page-about .team-card p {
  margin: 0 0 16px;
  font-size: 15px;
  line-height: 1.85;
  color: var(--text-body);
}

.page-about .team-card__keys {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .team-card__keys li {
  padding: 4px 9px;
  border: 1px solid var(--about-rule);
  font-family: var(--font-index);
  font-size: 11.5px;
  letter-spacing: 0.1em;
  color: var(--text-mute);
  opacity: 0.6;
  transition: opacity 0.2s ease, color 0.2s ease, border-color 0.2s ease;
}

.page-about .team-card:hover .team-card__keys li,
.page-about .team-card:focus-within .team-card__keys li {
  opacity: 1;
  color: var(--flag-white);
  border-color: var(--flag-blue);
}

/* ---------- 四道工序 ---------- */
.page-about .steps {
  display: grid;
  gap: 0;
  margin-top: 30px;
  border: var(--stroke) solid var(--about-rule);
  background: var(--ink-archive);
}

.page-about .step {
  padding: 22px 20px;
  border-top: var(--stroke) solid var(--about-rule);
}

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

.page-about .step::before {
  content: "";
  display: block;
  width: 34px;
  height: 3px;
  margin-bottom: 14px;
  background: var(--flag-blue);
}

.page-about .step:nth-child(2)::before { background: var(--flag-yellow); }
.page-about .step:nth-child(3)::before { background: var(--flag-green); }
.page-about .step:nth-child(4)::before { background: var(--amber); }

.page-about .step__no {
  margin: 0;
  font-size: 11.5px;
  letter-spacing: 0.18em;
  color: var(--text-mute);
}

.page-about .step h3 {
  margin: 10px 0 8px;
  font-family: var(--font-display);
  font-size: 18px;
  letter-spacing: 0.06em;
  color: var(--text-strong);
}

.page-about .step p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.85;
  color: var(--text-body);
}

/* ---------- 联赛层级 ---------- */
.page-about .levels {
  display: grid;
  gap: 28px;
  margin-top: 30px;
}

.page-about .level-list {
  list-style: none;
  margin: 0;
  padding: 0;
  border-top: var(--stroke) solid var(--about-rule);
}

.page-about .level-list li {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 14px;
  padding: 16px 2px;
  border-bottom: var(--stroke) solid var(--about-rule);
}

.page-about .level-list__dot {
  width: 12px;
  height: 12px;
  margin-top: 7px;
  background: var(--flag-blue);
}

.page-about .level-list__dot--blue { background: var(--flag-blue); }
.page-about .level-list__dot--green { background: var(--flag-green); }
.page-about .level-list__dot--yellow { background: var(--flag-yellow); }
.page-about .level-list__dot--amber { background: var(--amber); }

.page-about .level-list h3 {
  margin: 0 0 6px;
  font-family: var(--font-display);
  font-size: 17px;
  letter-spacing: 0.05em;
  color: var(--text-strong);
}

.page-about .level-list p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.8;
  color: var(--text-body);
}

/* ---------- 奖项与专题 ---------- */
.page-about .awards-grid {
  display: grid;
  gap: 30px;
  margin-top: 30px;
}

.page-about .awards-grid__h {
  margin: 0;
  font-family: var(--font-display);
  font-size: 19px;
  line-height: 1.5;
  letter-spacing: 0.04em;
  color: var(--text-strong);
}

.page-about .awards-grid .about-lead {
  margin-top: 12px;
}

.page-about .award-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  list-style: none;
  margin: 20px 0 0;
  padding: 0;
}

.page-about .award-tags .tag {
  display: inline-flex;
  align-items: center;
  height: 26px;
  padding: 0 10px;
  border: 1px solid var(--about-rule);
  font-family: var(--font-index);
  font-size: 12px;
  letter-spacing: 0.08em;
}

/* ---------- 合作生态 ---------- */
.page-about .coop-list {
  list-style: none;
  margin: 26px 0 0;
  padding: 0;
  display: grid;
  gap: 0;
  border-top: var(--stroke) solid var(--about-rule);
}

.page-about .coop-list li {
  padding: 18px 2px;
  border-bottom: var(--stroke) solid var(--about-rule);
}

.page-about .coop-list__key {
  display: block;
  margin-bottom: 8px;
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--amber);
}

.page-about .coop-list p {
  margin: 0;
  max-width: 40em;
  font-size: 15px;
  line-height: 1.85;
  color: var(--text-body);
}

/* ---------- 成长节点 ---------- */
.page-about .about-milestone {
  background-image: radial-gradient(circle, rgba(52, 89, 148, 0.42) 1px, transparent 1px);
  background-size: 22px 22px;
}

.page-about .milestones {
  list-style: none;
  margin: 30px 0 0;
  padding: 0;
  display: grid;
  gap: 16px;
}

.page-about .milestones li {
  position: relative;
  padding-left: 26px;
  max-width: 44em;
  font-size: 15px;
  line-height: 1.9;
  color: var(--text-body);
}

.page-about .milestones li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 10px;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--flag-yellow);
  box-shadow: 0 0 0 3px rgba(232, 179, 60, 0.22);
}

.page-about .milestones strong {
  color: var(--flag-white);
  font-family: var(--font-index);
  font-size: 1.02em;
}

/* ---------- 联系 ---------- */
.page-about .contact-grid {
  display: grid;
  gap: 20px;
  margin-top: 30px;
}

.page-about .contact-card {
  padding: 24px 22px;
  border: var(--stroke) solid var(--about-rule);
  border-left: var(--stroke-fat) solid var(--amber);
  background: var(--ink-archive);
  box-shadow: var(--hard-shadow-sm);
}

.page-about .contact-card h3 {
  margin: 0 0 12px;
  font-family: var(--font-display);
  font-size: 20px;
  letter-spacing: 0.05em;
  color: var(--text-strong);
}

.page-about .contact-card p {
  margin: 0 0 18px;
  font-size: 15px;
  line-height: 1.85;
  color: var(--text-body);
}

.page-about .contact-lines {
  display: grid;
  gap: 10px;
  margin-top: 26px;
  font-size: 14.5px;
  line-height: 1.8;
  color: var(--text-body);
}

.page-about .contact-lines p {
  margin: 0;
}

.page-about .contact-lines .mono {
  margin-right: 12px;
  font-size: 12px;
  letter-spacing: 0.12em;
  color: var(--text-mute);
}

.page-about .contact-lines__note {
  max-width: 42em;
  padding-top: 8px;
  border-top: 1px solid var(--about-rule);
  color: var(--text-mute);
}

/* ---------- 响应式 ---------- */
@media (min-width: 600px) {
  .page-about .milestones {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 16px 34px;
  }
}

@media (min-width: 780px) {
  .page-about .steps {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .step {
    border-top: 0;
    border-left: var(--stroke) solid var(--about-rule);
  }

  .page-about .step:first-child {
    border-left: 0;
  }

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

  .page-about .awards-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 40px;
  }
}

@media (min-width: 860px) {
  .page-about .team-grid {
    grid-template-columns: repeat(5, minmax(0, 1fr));
    gap: 24px;
  }

  .page-about .team-card:nth-child(1) { grid-column: 1 / span 3; }
  .page-about .team-card:nth-child(2) { grid-column: 4 / span 2; }
  .page-about .team-card:nth-child(3) { grid-column: 2 / span 3; }
}

@media (min-width: 900px) {
  .page-about .about-hero__inner {
    grid-template-columns: minmax(0, 1.3fr) minmax(0, 0.7fr);
    align-items: end;
    gap: 56px;
  }

  .page-about .levels {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1.15fr);
    gap: 42px;
    align-items: start;
  }

  .page-about .about-team__figure {
    margin-top: 36px;
  }
}

@media (min-width: 1080px) {
  .page-about .about-hero {
    padding-top: 40px;
  }

  .page-about .timeline {
    margin-top: 44px;
  }
}

/* ---------- 动效降级 ---------- */
@media (prefers-reduced-motion: reduce) {
  .page-about .node,
  .page-about .team-card,
  .page-about .team-card__keys li {
    transition: none;
  }
}