.page-about {
  --about-rail: 238px;
  --about-gap: clamp(24px, 3.6vw, 56px);
  --about-panel-ink: #E8EEF9;
}

/* 面包屑 */
.page-about .about-crumbs {
  padding-top: clamp(16px, 2.4vw, 28px);
  padding-bottom: clamp(6px, 1.4vw, 14px);
}

/* 首屏分屏 */
.page-about .about-hero {
  padding-bottom: clamp(34px, 5.5vw, 72px);
}

.page-about .about-hero__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(28px, 4vw, 60px);
  align-items: start;
}

@media (min-width: 900px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
  }
}

.page-about .about-hero__lead .eyebrow {
  margin: 0 0 14px;
}

.page-about .about-hero__lead h1 {
  margin: 0 0 20px;
}

.page-about .about-hero__lead .lead {
  margin: 0 0 26px;
  max-width: 33em;
  font-size: clamp(1rem, 0.5vw + 0.86rem, 1.125rem);
  line-height: 1.85;
  color: var(--ink-2);
}

/* 关键数字索引 */
.page-about .about-index {
  padding: clamp(20px, 2.6vw, 30px);
}

.page-about .about-index__title {
  margin: 0 0 16px;
  font-family: var(--mono);
  font-size: 0.75rem;
  letter-spacing: 0.16em;
  color: var(--ink-2);
}

.page-about .about-index__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 0 26px;
}

@media (min-width: 640px) {
  .page-about .about-index__list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

.page-about .about-index__list li {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  grid-template-rows: auto auto;
  column-gap: 12px;
  padding: 12px 0;
  border-top: 1px solid var(--rule);
}

.page-about .about-index__num {
  grid-row: 1 / 3;
  font-family: var(--mono);
  font-size: 0.6875rem;
  color: var(--blue);
  padding-top: 0.4em;
}

.page-about .about-index__val {
  font-family: var(--mono);
  font-size: 1.1875rem;
  font-weight: 700;
  letter-spacing: -0.01em;
  color: var(--ink);
  line-height: 1.3;
}

.page-about .about-index__label {
  font-size: 0.8125rem;
  line-height: 1.6;
  color: var(--ink-2);
}

.page-about .about-hero__media {
  margin: clamp(24px, 3vw, 34px) 0 0;
}

/* 主体：左轨目录 + 右内容 */
.page-about .about-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--about-gap);
  padding-bottom: clamp(44px, 6vw, 84px);
}

@media (min-width: 1000px) {
  .page-about .about-layout {
    grid-template-columns: var(--about-rail) minmax(0, 1fr);
    align-items: start;
  }
}

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

@media (min-width: 1000px) {
  .page-about .about-rail {
    display: block;
    position: sticky;
    top: 108px;
    padding-top: 46px;
  }
}

.page-about .about-rail__title {
  margin: 0 0 12px;
  font-family: var(--mono);
  font-size: 0.6875rem;
  letter-spacing: 0.18em;
  color: var(--ink-2);
}

.page-about .about-toc {
  list-style: none;
  margin: 0;
  padding: 0;
  position: relative;
}

.page-about .about-toc::before {
  content: "";
  position: absolute;
  left: 7px;
  top: 12px;
  bottom: 12px;
  width: 1px;
  background: var(--rule);
}

.page-about .about-toc a {
  position: relative;
  display: flex;
  align-items: baseline;
  gap: 9px;
  padding: 8px 0 8px 24px;
  font-size: 0.8125rem;
  line-height: 1.5;
  color: var(--ink-2);
  text-decoration: none;
  transition: color 0.25s ease;
}

.page-about .about-toc a::before {
  content: "";
  position: absolute;
  left: 3px;
  top: 13px;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--paper);
  border: 1px solid var(--rule);
  transition: background 0.25s ease, border-color 0.25s ease, box-shadow 0.25s ease;
}

.page-about .about-toc a .num {
  font-family: var(--mono);
  font-size: 0.6875rem;
  color: var(--blue);
}

.page-about .about-toc a:hover {
  color: var(--ink);
}

.page-about .about-toc a[aria-current="true"] {
  color: var(--ink);
  font-weight: 600;
}

.page-about .about-toc a[aria-current="true"]::before {
  background: var(--blue);
  border-color: var(--blue);
  box-shadow: 0 0 0 4px var(--blue-soft);
}

/* 章节 */
.page-about .chapter {
  padding: clamp(36px, 5vw, 68px) 0;
  border-top: 1px solid var(--rule);
}

.page-about .about-body > .chapter:first-child {
  border-top: 0;
  padding-top: 0;
}

.page-about .chapter-head {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 8px;
  margin-bottom: clamp(20px, 2.6vw, 32px);
}

@media (min-width: 720px) {
  .page-about .chapter-head {
    grid-template-columns: 68px minmax(0, 1fr);
    gap: 20px;
    align-items: baseline;
  }
}

.page-about .chapter-num {
  margin: 0;
  font-family: var(--mono);
  font-size: 0.8125rem;
  letter-spacing: 0.14em;
  color: var(--blue);
}

.page-about .chapter-title {
  margin: 0;
  font-size: clamp(1.4rem, 2vw + 0.9rem, 2.375rem);
  font-weight: 700;
  line-height: 1.28;
  letter-spacing: -0.01em;
  color: var(--ink);
}

.page-about .prose {
  max-width: 68ch;
  margin: 0;
  font-size: 0.9375rem;
  line-height: 1.85;
  color: var(--ink-2);
}

/* 图片通用 */
.page-about img {
  max-width: 100%;
  height: auto;
  display: block;
  object-fit: cover;
}

.page-about .about-history__media {
  margin: clamp(24px, 3vw, 36px) 0;
}

/* 三件坚持 */
.page-about .about-cards {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(16px, 2vw, 24px);
}

@media (min-width: 780px) {
  .page-about .about-cards {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

.page-about .about-card {
  display: flex;
  flex-direction: column;
  gap: 12px;
  padding: clamp(20px, 2.4vw, 28px);
}

.page-about .about-card .tag {
  align-self: flex-start;
}

.page-about .about-card .card-title {
  margin: 0;
  font-size: 1.0625rem;
  line-height: 1.55;
  letter-spacing: -0.01em;
}

.page-about .about-card p:last-child {
  margin: 0;
  font-size: 0.9375rem;
  line-height: 1.82;
  color: var(--ink-2);
}

/* 发展历程 */
.page-about .about-track {
  border-top: 1px solid var(--rule);
}

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

.page-about .about-node > summary {
  display: grid;
  grid-template-columns: 78px minmax(0, 1fr) auto;
  gap: 6px 14px;
  align-items: baseline;
  padding: 18px 6px;
  cursor: pointer;
  list-style: none;
}

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

.page-about .about-node > summary::marker {
  content: "";
}

.page-about .about-node__gen {
  font-family: var(--mono);
  font-size: 0.6875rem;
  letter-spacing: 0.1em;
  color: var(--blue);
}

.page-about .about-node__title {
  font-size: 1rem;
  font-weight: 600;
  line-height: 1.55;
  color: var(--ink);
}

.page-about .about-node__hint {
  width: 1.4em;
  text-align: center;
  font-family: var(--mono);
  font-size: 1rem;
  color: var(--ink-2);
}

.page-about .about-node__hint::before {
  content: "+";
}

.page-about .about-node[open] .about-node__hint::before {
  content: "–";
}

.page-about .about-node[open] .about-node__hint {
  color: var(--blue);
}

.page-about .about-node__body {
  max-width: 64ch;
  padding: 0 6px 22px 98px;
}

.page-about .about-node__body p {
  margin: 0;
  font-size: 0.9375rem;
  line-height: 1.85;
  color: var(--ink-2);
}

@media (max-width: 640px) {
  .page-about .about-node__body {
    padding-left: 6px;
  }
}

/* 团队 */
.page-about .about-roles {
  margin: 0;
  border-top: 1px solid var(--rule);
}

.page-about .about-role {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 6px;
  padding: 20px 4px;
  border-bottom: 1px solid var(--rule);
}

@media (min-width: 760px) {
  .page-about .about-role {
    grid-template-columns: 208px minmax(0, 1fr);
    gap: 28px;
    align-items: baseline;
  }
}

.page-about .about-role dt {
  font-family: var(--mono);
  font-size: 0.8125rem;
  letter-spacing: 0.06em;
  color: var(--blue);
}

.page-about .about-role dd {
  margin: 0;
  max-width: 64ch;
  font-size: 0.9375rem;
  line-height: 1.85;
  color: var(--ink-2);
}

.page-about .about-roles__total {
  margin: 22px 0 0;
  max-width: 68ch;
  font-size: 0.9375rem;
  line-height: 1.85;
  color: var(--ink);
}

/* 版本归档 */
.page-about .about-archive {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(22px, 3vw, 40px);
  align-items: start;
}

@media (min-width: 880px) {
  .page-about .about-archive {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
  }
}

.page-about .about-lines {
  list-style: none;
  margin: 20px 0 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.page-about .about-lines li {
  padding: 6px 12px;
  border: 1px solid var(--rule);
  border-radius: var(--r-s);
  background: var(--card);
  font-family: var(--mono);
  font-size: 0.75rem;
  color: var(--ink-2);
}

.page-about .about-archive__note {
  margin: 20px 0 0;
  max-width: 66ch;
  font-size: 0.875rem;
  line-height: 1.8;
  color: var(--ink-2);
  padding-left: 14px;
  border-left: 2px solid var(--cyan);
}

.page-about .about-archive__media {
  margin: 0;
}

/* 更新节奏面板 */
.page-about .about-rhythm {
  margin-top: clamp(24px, 3vw, 38px);
  padding: clamp(22px, 2.8vw, 34px);
  border: 1px solid rgba(255, 255, 255, 0.08);
  border-radius: var(--r);
  background: var(--night);
  color: var(--about-panel-ink);
}

.page-about .about-rhythm .panel-title {
  margin: 0 0 18px;
  font-family: var(--mono);
  font-size: 0.6875rem;
  letter-spacing: 0.18em;
  color: var(--cyan);
}

.page-about .about-rhythm__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 0;
}

@media (min-width: 760px) {
  .page-about .about-rhythm__list {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 0 28px;
  }
}

.page-about .about-rhythm__list li {
  padding: 16px 0;
  border-top: 1px solid rgba(255, 255, 255, 0.14);
}

.page-about .about-rhythm__list .num {
  display: block;
  margin-bottom: 6px;
  font-family: var(--mono);
  font-size: 1.125rem;
  font-weight: 700;
  letter-spacing: -0.01em;
  color: #FFFFFF;
}

.page-about .about-rhythm__list span:last-child {
  display: block;
  font-size: 0.875rem;
  line-height: 1.72;
  color: rgba(232, 238, 249, 0.72);
}

/* 服务覆盖 */
.page-about .about-coverage {
  margin-top: clamp(22px, 3vw, 34px);
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  background: var(--rule);
  border: 1px solid var(--rule);
  border-radius: var(--r);
  overflow: hidden;
}

@media (min-width: 640px) {
  .page-about .about-coverage {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (min-width: 960px) {
  .page-about .about-coverage {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

.page-about .about-coverage__item {
  padding: clamp(20px, 2.4vw, 28px);
  background: var(--card);
}

.page-about .about-coverage__val {
  margin: 0 0 8px;
  font-family: var(--mono);
  font-size: clamp(1.375rem, 1.4vw + 0.95rem, 1.875rem);
  font-weight: 700;
  letter-spacing: -0.02em;
  line-height: 1.2;
  color: var(--ink);
}

.page-about .about-coverage__item:nth-child(6) .about-coverage__val {
  color: var(--blue);
}

.page-about .about-coverage__label {
  margin: 0;
  font-size: 0.875rem;
  line-height: 1.68;
  color: var(--ink-2);
}

.page-about .about-coverage__foot {
  margin: clamp(20px, 2.6vw, 30px) 0 0;
  max-width: 68ch;
  font-size: 0.9375rem;
  line-height: 1.85;
  color: var(--ink-2);
}

/* 荣誉与合作 */
.page-about .about-eco {
  margin-top: clamp(22px, 3vw, 34px);
  padding: clamp(20px, 2.6vw, 32px);
  border: 1px solid var(--rule);
  border-radius: var(--r);
  background: linear-gradient(135deg, var(--blue-soft) 0%, var(--violet-soft) 62%, var(--cyan-soft) 100%);
}

.page-about .about-eco__title {
  margin: 0 0 16px;
  font-family: var(--mono);
  font-size: 0.6875rem;
  letter-spacing: 0.18em;
  color: var(--violet);
}

.page-about .about-eco__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 12px 28px;
}

@media (min-width: 700px) {
  .page-about .about-eco__list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

.page-about .about-eco__list li {
  position: relative;
  padding-left: 20px;
  font-size: 0.9375rem;
  line-height: 1.72;
  color: var(--ink);
}

.page-about .about-eco__list li::before {
  content: "";
  position: absolute;
  left: 2px;
  top: 0.68em;
  width: 8px;
  height: 2px;
  background: var(--blue);
}

.page-about .about-eco__closing {
  margin: 22px 0 0;
  max-width: 68ch;
  font-size: 0.9375rem;
  line-height: 1.85;
  color: var(--ink-2);
}

/* 章节跳转 */
.page-about .about-next {
  margin-top: clamp(38px, 5vw, 64px);
  padding: clamp(24px, 3vw, 36px);
  border: 1px solid var(--rule);
  border-radius: var(--r);
  background: var(--card);
}

.page-about .about-next__title {
  margin: 0 0 16px;
  font-size: 1.125rem;
  font-weight: 700;
  letter-spacing: -0.01em;
  color: var(--ink);
}

.page-about .about-next__foot {
  margin-top: 22px;
  padding-top: 18px;
  border-top: 1px solid var(--rule);
  display: flex;
  justify-content: flex-end;
}

/* 窄屏兜底 */
@media (max-width: 480px) {
  .page-about .about-index__val {
    font-size: 1.0625rem;
  }

  .page-about .about-node > summary {
    grid-template-columns: minmax(0, 1fr) auto;
  }

  .page-about .about-node__gen {
    grid-column: 1 / -1;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-toc a,
  .page-about .about-toc a::before {
    transition: none;
  }
}