.page-about {
  --about-gap: clamp(18px, 3vw, 32px);
  background: var(--ink);
  color: var(--white);
  font-family: var(--font-body);
  line-height: 1.75;
}

.page-about a:focus-visible,
.page-about button:focus-visible,
.page-about summary:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 3px;
  border-radius: 6px;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  padding: clamp(24px, 4.5vw, 56px) 0 clamp(34px, 5vw, 64px);
  border-bottom: 1px solid var(--line);
  background:
    radial-gradient(1100px 420px at 88% -12%, rgba(56, 225, 214, 0.10), transparent 70%),
    radial-gradient(720px 340px at -5% 108%, rgba(18, 60, 58, 0.62), transparent 72%);
}

.page-about .breadcrumb {
  margin-bottom: clamp(16px, 2.6vw, 26px);
}

.page-about .about-hero__grid {
  display: grid;
  gap: clamp(22px, 3.4vw, 40px);
}

.page-about .about-hero__copy {
  min-width: 0;
}

.page-about .eyebrow {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--cyan);
}

.page-about .about-hero__title {
  margin: 12px 0 0;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(40px, 9vw, 86px);
  line-height: 0.98;
  letter-spacing: -0.02em;
}

.page-about .about-hero__title span {
  display: block;
  color: var(--cyan);
}

.page-about .about-hero__lede {
  max-width: 48ch;
  margin: clamp(16px, 2.4vw, 24px) 0 0;
  font-size: clamp(15.5px, 1.7vw, 18px);
  color: rgba(245, 249, 252, 0.82);
}

.page-about .about-hero__cta {
  margin-top: clamp(20px, 3vw, 30px);
}

/* ---------- 图片容器 ---------- */
.page-about .about-figure {
  margin: clamp(20px, 3vw, 30px) 0 0;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--panel-2);
}

.page-about .about-hero__figure {
  margin: 0;
  align-self: end;
  box-shadow: 0 24px 60px rgba(5, 10, 24, 0.55);
}

.page-about .about-figure img {
  display: block;
  width: 100%;
  height: auto;
}

.page-about .about-figure figcaption {
  padding: 10px 14px;
  border-top: 1px solid var(--line);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--mist);
}

/* ---------- 关键数据 ---------- */
.page-about .about-metrics {
  list-style: none;
  margin: clamp(28px, 4vw, 44px) 0 0;
  padding: clamp(18px, 2.6vw, 24px) 0 0;
  border-top: 1px solid var(--line);
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 18px 20px;
}

.page-about .about-metrics__num {
  display: block;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(26px, 3.6vw, 40px);
  line-height: 1.1;
  color: var(--gold);
}

.page-about .about-metrics__label {
  display: block;
  margin-top: 4px;
  font-size: 13px;
  color: var(--mist);
}

/* ---------- 章节导航 ---------- */
.page-about .about-toc {
  margin-top: clamp(24px, 3.5vw, 36px);
}

.page-about .about-toc__list {
  list-style: none;
  display: flex;
  gap: 8px;
  margin: 0;
  padding: 0 0 6px;
  overflow-x: auto;
  scrollbar-width: thin;
}

.page-about .about-toc__link {
  display: inline-flex;
  align-items: baseline;
  gap: 8px;
  white-space: nowrap;
  padding: 8px 14px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: var(--panel-2);
  color: var(--mist);
  font-size: 13px;
  text-decoration: none;
  transition: color 0.2s ease, border-color 0.2s ease;
}

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

.page-about .about-toc__num {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--gold);
}

/* ---------- 章节骨架 ---------- */
.page-about .about-chapter {
  padding: clamp(40px, 6vw, 76px) 0;
  border-bottom: 1px solid var(--line);
}

.page-about .about-chapter--panel {
  background: linear-gradient(180deg, rgba(17, 28, 58, 0.36), rgba(11, 19, 43, 0));
}

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

.page-about .about-chapter__head {
  min-width: 0;
}

.page-about .about-chapter__index {
  display: block;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(44px, 6.4vw, 70px);
  line-height: 0.9;
  color: var(--gold);
  opacity: 0.88;
}

.page-about .about-chapter__head .eyebrow {
  margin-top: 10px;
  color: var(--mist);
}

.page-about .about-chapter__head .section-title {
  margin: 6px 0 0;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(24px, 3.4vw, 36px);
  line-height: 1.2;
  letter-spacing: -0.01em;
}

.page-about .about-chapter__body {
  min-width: 0;
}

.page-about .about-chapter__body > p {
  margin: 0 0 clamp(14px, 2vw, 18px);
  font-size: clamp(15.5px, 1.6vw, 17px);
  color: rgba(245, 249, 252, 0.84);
}

.page-about .about-chapter__note {
  margin: clamp(18px, 2.6vw, 24px) 0 0;
  padding-left: 16px;
  border-left: 2px solid var(--cyan);
  font-size: 15px;
  color: rgba(245, 249, 252, 0.76);
}

.page-about .about-inline-link {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(56, 225, 214, 0.45);
}

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

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

.page-about .about-timeline__item {
  position: relative;
  display: grid;
  grid-template-columns: 62px minmax(0, 1fr);
  gap: 14px;
  padding: 20px 0 20px 20px;
  border-left: 1px solid var(--line-strong);
}

.page-about .about-timeline__item::before {
  content: "";
  position: absolute;
  left: -5px;
  top: 28px;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--cyan);
  box-shadow: 0 0 0 4px rgba(56, 225, 214, 0.14);
}

.page-about .about-timeline__item:last-child::before {
  background: var(--gold);
  box-shadow: 0 0 0 4px rgba(242, 184, 75, 0.16);
}

.page-about .about-timeline__year {
  font-family: var(--font-mono);
  font-size: 17px;
  letter-spacing: 0.04em;
  color: var(--gold);
  line-height: 1.5;
}

.page-about .about-timeline__text h3 {
  margin: 0 0 6px;
  font-size: 17px;
  font-weight: 600;
  line-height: 1.45;
}

.page-about .about-timeline__text p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.72;
  color: rgba(245, 249, 252, 0.74);
}

/* ---------- 改版卡片 ---------- */
.page-about .about-cards {
  display: grid;
  gap: 14px;
  margin-top: clamp(20px, 3vw, 28px);
}

.page-about .about-card {
  padding: 20px 18px;
  border: 1px solid var(--line);
  border-top: 2px solid var(--cyan);
  border-radius: var(--radius-sm) var(--radius) var(--radius) var(--radius);
  background: var(--panel);
}

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

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

.page-about .about-card__kicker {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--mist);
}

.page-about .about-card__title {
  margin: 8px 0 6px;
  font-size: 18px;
  font-weight: 600;
  line-height: 1.4;
}

.page-about .about-card__text {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.7;
  color: rgba(245, 249, 252, 0.76);
}

/* ---------- 维护节奏标签页 ---------- */
.page-about .about-rhythm {
  margin-top: clamp(22px, 3vw, 30px);
}

.page-about .tab-list {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  padding-bottom: 14px;
  border-bottom: 1px solid var(--line);
}

.page-about .tab {
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: 0.02em;
  padding: 9px 15px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: var(--panel-2);
  color: var(--mist);
  cursor: pointer;
  transition: color 0.2s ease, background-color 0.2s ease, border-color 0.2s ease;
}

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

.page-about .tab[aria-selected="true"] {
  background: var(--cyan);
  border-color: var(--cyan);
  color: var(--ink);
}

.page-about .tab-panel {
  padding-top: clamp(18px, 2.6vw, 24px);
}

.page-about .tab-panel h3 {
  margin: 0 0 8px;
  font-size: 18px;
  font-weight: 600;
  color: var(--white);
}

.page-about .tab-panel p {
  margin: 0;
  font-size: 15px;
  line-height: 1.75;
  color: rgba(245, 249, 252, 0.78);
}

/* ---------- 团队协作 ---------- */
.page-about .about-team {
  padding: clamp(20px, 3.6vw, 36px);
  border: 1px solid var(--line);
  border-radius: 28px 28px 28px 8px;
  background: linear-gradient(158deg, rgba(18, 60, 58, 0.92), rgba(17, 28, 58, 0.94) 62%, rgba(11, 19, 43, 0.96));
}

.page-about .about-team__lede {
  margin: 0 0 clamp(14px, 2vw, 20px);
  font-size: 15.5px;
  line-height: 1.75;
  color: rgba(245, 249, 252, 0.86);
}

.page-about .about-team__item {
  padding: 14px 0;
  border-top: 1px solid rgba(143, 166, 178, 0.28);
}

.page-about .about-team__summary {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  cursor: pointer;
  list-style: none;
  font-size: 17px;
  font-weight: 600;
  color: var(--white);
}

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

.page-about .about-team__summary::after {
  content: "+";
  font-family: var(--font-mono);
  font-size: 18px;
  color: var(--cyan);
}

.page-about .about-team__item[open] .about-team__summary::after {
  content: "−";
  color: var(--gold);
}

.page-about .about-team__body {
  margin: 10px 0 0;
  font-size: 14.5px;
  line-height: 1.75;
  color: rgba(245, 249, 252, 0.78);
}

/* ---------- 服务步骤 ---------- */
.page-about .about-steps {
  list-style: none;
  margin: clamp(20px, 3vw, 28px) 0 0;
  padding: 0;
  display: grid;
  gap: 12px;
}

.page-about .about-step {
  display: grid;
  grid-template-columns: 40px minmax(0, 1fr);
  gap: 12px;
  padding: 16px;
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  background: var(--panel-2);
}

.page-about .about-step__num {
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.06em;
  color: var(--gold);
  padding-top: 2px;
}

.page-about .about-step h3 {
  margin: 0 0 6px;
  font-size: 16.5px;
  font-weight: 600;
}

.page-about .about-step p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.7;
  color: rgba(245, 249, 252, 0.76);
}

.page-about .about-links {
  display: flex;
  flex-wrap: wrap;
  gap: 10px 24px;
  margin-top: clamp(22px, 3vw, 30px);
}

.page-about .about-links .link-arrow {
  color: var(--cyan);
  font-size: 14.5px;
}

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

/* ---------- 响应式 ---------- */
@media (min-width: 620px) {
  .page-about .about-cards {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

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

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

  .page-about .about-toc__list {
    flex-wrap: wrap;
    overflow-x: visible;
  }

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

@media (min-width: 920px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 1.15fr) minmax(0, 0.85fr);
    align-items: end;
    gap: clamp(26px, 4vw, 56px);
  }

  .page-about .about-chapter__grid {
    grid-template-columns: 190px minmax(0, 1fr);
    gap: clamp(28px, 5vw, 64px);
  }

  .page-about .about-chapter__head {
    position: sticky;
    top: 96px;
    align-self: start;
  }

  .page-about .about-timeline__item {
    grid-template-columns: 84px minmax(0, 1fr);
    gap: 20px;
  }
}

@media (min-width: 1140px) {
  .page-about .about-timeline {
    padding-right: clamp(0px, 3vw, 40px);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-toc__link,
  .page-about .tab {
    transition: none;
  }
}