.page-about {
  --about-text: #C6D9CF;
  --about-rail-w: 210px;
  --about-gap: clamp(32px, 4.5vw, 72px);
  --about-pad: clamp(18px, 2.4vw, 28px);
  background: var(--night);
  color: var(--score);
  padding-top: calc(var(--header-h) + clamp(24px, 4vw, 56px));
  overflow-x: clip;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  padding-bottom: clamp(40px, 6vw, 72px);
}

.page-about .about-kicker {
  margin: clamp(20px, 3vw, 36px) 0 14px;
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  letter-spacing: 0.18em;
  color: var(--moss);
}

.page-about .about-title {
  margin: 0 0 clamp(18px, 2.4vw, 28px);
  font-size: clamp(2rem, 4.8vw, 3.6rem);
  line-height: 1.06;
  letter-spacing: -0.01em;
  color: var(--score);
  max-width: 18ch;
  overflow-wrap: break-word;
}

.page-about .about-lede {
  max-width: 46em;
  margin: 0;
  font-size: clamp(1rem, 1.1vw, 1.125rem);
  line-height: 1.8;
  color: var(--moss);
}

.page-about .about-figures {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: clamp(32px, 4.5vw, 56px) 0 0;
  padding: 0;
  background: var(--line);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.page-about .about-figure {
  background: var(--turf);
  padding: clamp(18px, 2.2vw, 28px) clamp(16px, 2vw, 24px);
}

.page-about .about-figure dt {
  margin: 0 0 10px;
  font-size: 0.8125rem;
  letter-spacing: 0.12em;
  color: var(--moss);
}

.page-about .about-figure dd {
  display: flex;
  align-items: baseline;
  gap: 6px;
  margin: 0;
  font-family: var(--font-mono);
  font-size: clamp(1.6rem, 2.8vw, 2.3rem);
  line-height: 1;
  color: var(--score);
}

.page-about .about-figure__unit {
  font-family: var(--font-body);
  font-size: 0.875rem;
  letter-spacing: 0.04em;
  color: var(--moss);
}

/* ---------- 画布与目录 ---------- */
.page-about .about-canvas {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(32px, 5vw, 52px);
  padding-top: clamp(48px, 7vw, 92px);
  padding-bottom: clamp(48px, 7vw, 96px);
}

.page-about .about-rail {
  align-self: start;
}

.page-about .about-rail__label {
  margin: 0 0 6px;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--line);
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.18em;
  color: var(--moss);
}

.page-about .about-rail__list {
  display: flex;
  flex-wrap: wrap;
  gap: 4px 18px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .about-rail__link {
  display: flex;
  align-items: baseline;
  gap: 10px;
  padding: 8px 0;
  font-size: 0.875rem;
  line-height: 1.5;
  color: var(--moss);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.page-about .about-rail__link .data-num {
  flex: none;
  font-size: 0.75rem;
  color: var(--stand);
}

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

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

/* ---------- 章节 ---------- */
.page-about .about-chapter {
  padding-bottom: clamp(52px, 6.5vw, 88px);
}

.page-about .about-chapter + .about-chapter {
  padding-top: clamp(52px, 6.5vw, 88px);
  border-top: 1px solid var(--line);
}

.page-about .about-chapter__head {
  display: flex;
  align-items: baseline;
  gap: clamp(12px, 1.8vw, 20px);
  margin-bottom: 14px;
}

.page-about .about-chapter__index {
  flex: none;
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  letter-spacing: 0.1em;
  color: var(--stand);
}

.page-about .about-chapter__title {
  margin: 0;
  color: var(--score);
  overflow-wrap: break-word;
}

.page-about .about-chapter__body {
  max-width: 44em;
}

.page-about .about-chapter__body + .about-chapter__body {
  margin-top: clamp(20px, 3vw, 32px);
}

.page-about .about-chapter__body p {
  margin: 0 0 1.1em;
  font-size: 1.0625rem;
  line-height: 1.8;
  color: var(--about-text);
}

.page-about .about-chapter__body p:last-child {
  margin-bottom: 0;
}

.page-about a:not(.btn):not(.about-rail__link):not(.about-next__link) {
  color: var(--pulse);
  text-decoration: underline;
  text-underline-offset: 3px;
  text-decoration-thickness: 1px;
}

/* ---------- 团队分工 ---------- */
.page-about .about-roles {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  margin: clamp(26px, 3.6vw, 44px) 0 0;
  background: var(--line);
}

.page-about .about-role {
  background: var(--turf);
  padding: var(--about-pad);
}

.page-about .about-role__name {
  margin: 0 0 10px;
  padding-left: 12px;
  border-left: 2px solid var(--pulse);
  font-family: var(--font-body);
  font-size: 1rem;
  font-weight: 600;
  letter-spacing: 0.06em;
  color: var(--score);
}

.page-about .about-role p {
  margin: 0;
  font-size: 0.9375rem;
  line-height: 1.75;
  color: var(--about-text);
}

.page-about .about-inline-media {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(20px, 3vw, 32px);
  align-items: center;
  margin-top: clamp(28px, 4vw, 48px);
}

.page-about .about-note {
  margin: 0;
  padding-left: clamp(16px, 2vw, 24px);
  border-left: 2px solid var(--line);
  font-family: var(--font-serif);
  font-size: 1rem;
  line-height: 1.9;
  color: var(--moss);
}

/* ---------- 时效清单 ---------- */
.page-about .about-assure {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  margin: clamp(24px, 3.5vw, 40px) 0 0;
  padding: 0;
  list-style: none;
  background: var(--line);
}

.page-about .about-assure li {
  display: flex;
  align-items: baseline;
  gap: 10px;
  padding: clamp(18px, 2.2vw, 26px) clamp(16px, 2vw, 24px);
  background: var(--mid);
}

.page-about .about-assure__num {
  font-family: var(--font-mono);
  font-size: clamp(1.75rem, 3vw, 2.4rem);
  line-height: 1;
  color: var(--flare);
}

.page-about .about-assure__txt {
  font-size: 0.9375rem;
  line-height: 1.6;
  color: var(--about-text);
}

/* ---------- 栏目 ---------- */
.page-about .about-columns {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  margin: clamp(26px, 3.6vw, 44px) 0 0;
  padding: 0;
  list-style: none;
  background: var(--line);
}

.page-about .about-columns__item {
  background: var(--turf);
  padding: var(--about-pad);
}

.page-about .about-columns__name {
  margin: 0 0 8px;
  font-family: var(--font-serif);
  font-size: 1.125rem;
  font-weight: 600;
  color: var(--score);
}

.page-about .about-columns__item p {
  margin: 0;
  font-size: 0.9375rem;
  line-height: 1.75;
  color: var(--about-text);
}

/* ---------- 开放能力 ---------- */
.page-about .about-apis {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: clamp(20px, 3vw, 32px) 0 0;
  padding: 0;
  list-style: none;
}

.page-about .about-apis li {
  padding: 7px 14px;
  border: 1px solid var(--edge);
  border-radius: var(--radius);
  background: rgba(127, 227, 208, 0.05);
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  letter-spacing: 0.06em;
  color: var(--pulse);
}

/* ---------- 服务与支持 ---------- */
.page-about .about-subtitle {
  margin: clamp(28px, 4vw, 42px) 0 0;
  font-family: var(--font-serif);
  font-size: 1.125rem;
  font-weight: 600;
  color: var(--score);
}

.page-about .about-a11y {
  margin-top: clamp(16px, 2.4vw, 24px);
  padding-top: clamp(18px, 2.6vw, 26px);
  border-top: 1px solid var(--line);
}

.page-about .about-a11y .tabs__list {
  display: flex;
  flex-wrap: wrap;
  gap: 6px 22px;
}

.page-about .about-a11y .tabs__panel p {
  max-width: 42em;
  margin: 18px 0 0;
  font-size: 0.9375rem;
  line-height: 1.8;
  color: var(--about-text);
}

/* ---------- 发展阶段时间轴 ---------- */
.page-about .about-timeline {
  --tl-pad: 30px;
  position: relative;
  display: grid;
  gap: clamp(24px, 3.4vw, 40px);
  margin: clamp(26px, 3.6vw, 44px) 0 0;
  padding: 0 0 0 var(--tl-pad);
  list-style: none;
}

.page-about .about-timeline::before {
  content: "";
  position: absolute;
  left: 6px;
  top: 8px;
  bottom: 8px;
  width: 1px;
  background: linear-gradient(to bottom, var(--line) 0%, var(--line) 76%, transparent 100%);
}

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

.page-about .about-stage__dot {
  position: absolute;
  left: calc(-1 * var(--tl-pad) + 2.5px);
  top: 7px;
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--flare);
  box-shadow: 0 0 0 3px rgba(255, 138, 61, 0.16);
}

.page-about .about-stage__tag {
  margin: 0 0 6px;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.16em;
  color: var(--moss);
}

.page-about .about-stage__name {
  margin: 0 0 8px;
  font-family: var(--font-serif);
  font-size: clamp(1.125rem, 1.6vw, 1.375rem);
  font-weight: 600;
  color: var(--score);
}

.page-about .about-stage__desc {
  max-width: 40em;
  margin: 0;
  font-size: 0.9375rem;
  line-height: 1.75;
  color: var(--about-text);
  overflow-wrap: break-word;
}

/* ---------- 图片 ---------- */
.page-about .about-chapter .media {
  margin: clamp(28px, 4vw, 48px) 0 0;
  overflow: hidden;
}

.page-about .media__img {
  display: block;
  max-width: 100%;
}

/* ---------- 收尾 ---------- */
.page-about .about-next {
  margin-top: clamp(56px, 8vw, 104px);
  padding: clamp(48px, 7vw, 88px) 0;
  background: var(--turf);
  border-top: 1px solid var(--line);
}

.page-about .about-next__title {
  margin: 0 0 14px;
  color: var(--score);
}

.page-about .about-next__text {
  max-width: 40em;
  margin: 0 0 clamp(24px, 3vw, 36px);
  font-size: 1.0625rem;
  line-height: 1.8;
  color: var(--moss);
}

.page-about .about-next__actions {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 18px 24px;
  margin: 0;
}

.page-about .about-next__link {
  padding-bottom: 3px;
  border-bottom: 1px solid var(--edge);
  font-size: 0.9375rem;
  letter-spacing: 0.04em;
  color: var(--pulse);
  text-decoration: none;
  transition: border-color var(--dur) var(--ease);
}

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

/* ---------- 断点 ---------- */
@media (min-width: 480px) {
  .page-about .about-assure {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

@media (min-width: 768px) {
  .page-about .about-figures {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

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

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

  .page-about .about-inline-media {
    grid-template-columns: minmax(0, 1.1fr) minmax(0, 0.9fr);
  }
}

@media (min-width: 1024px) {
  .page-about .about-canvas {
    grid-template-columns: var(--about-rail-w) minmax(0, 1fr);
    gap: var(--about-gap);
  }

  .page-about .about-rail {
    position: sticky;
    top: calc(var(--header-h) + 28px);
  }

  .page-about .about-rail__list {
    flex-direction: column;
    flex-wrap: nowrap;
    gap: 0;
  }

  .page-about .about-rail__link {
    padding: 9px 0;
  }

  .page-about .about-rail__link:hover,
  .page-about .about-rail__link:focus-visible {
    border-bottom-color: transparent;
  }

  .page-about .about-rail__link:hover span:last-child,
  .page-about .about-rail__link:focus-visible span:last-child {
    text-decoration: underline;
    text-underline-offset: 4px;
  }

  .page-about .about-chapter__index {
    font-size: 0.875rem;
  }
}

@media (min-width: 1440px) {
  .page-about {
    --about-rail-w: 236px;
  }
}

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