.page-about {
  background: var(--paper-50);
  color: var(--ink-900);
  overflow-x: clip;
}

/* ---------- 面包屑 ---------- */
.page-about .crumbs-wrap {
  padding-top: var(--space-3);
}

.page-about .crumbs {
  font-size: 13px;
  letter-spacing: .02em;
  color: var(--chart-600);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  padding-block: var(--space-5) var(--space-5);
  background:
    radial-gradient(85% 120% at 94% -10%, rgba(35, 224, 196, .16), transparent 62%),
    radial-gradient(70% 110% at 0% 110%, rgba(255, 122, 69, .11), transparent 60%);
}

.page-about .about-hero__grid {
  display: grid;
  gap: var(--space-4);
}

.page-about .about-hero__title {
  font-family: var(--font-serif);
  font-weight: 700;
  font-size: clamp(28px, 4.4vw, 50px);
  line-height: 1.32;
  letter-spacing: -0.01em;
  color: var(--abyss-900);
  margin: 10px 0 0;
  max-width: 17em;
}

.page-about .about-hero__lead {
  font-size: 16px;
  line-height: 1.9;
  color: var(--abyss-700);
  margin: 0;
  max-width: 34em;
  padding-top: var(--space-2);
  border-top: 2px solid var(--signal-500);
}

@media (min-width: 900px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 1.4fr) minmax(0, 1fr);
    gap: var(--space-5);
    align-items: end;
  }
}

/* ---------- 关键数字条 ---------- */
.page-about .fact-strip {
  list-style: none;
  margin: var(--space-5) 0 0;
  padding: var(--space-4) 0 0;
  border-top: 1px solid var(--hairline-light);
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: var(--space-3) var(--space-3);
}

@media (min-width: 800px) {
  .page-about .fact-strip {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

.page-about .fact {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.page-about .fact__num {
  font-family: var(--font-num);
  font-weight: 700;
  font-size: clamp(30px, 4.2vw, 46px);
  line-height: 1;
  letter-spacing: .01em;
  color: var(--abyss-900);
  font-variant-numeric: tabular-nums;
}

.page-about .fact__label {
  font-size: 13px;
  line-height: 1.6;
  color: var(--chart-600);
}

/* ---------- 通用小标题区 ---------- */
.page-about .about-head .section-title {
  max-width: 22em;
}

.page-about .about-prose {
  margin-top: var(--space-4);
}

.page-about .about-prose p {
  margin: 0 0 var(--space-3);
  line-height: 1.9;
}

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

/* ---------- 引文 ---------- */
.page-about .pullquote {
  margin: var(--space-5) 0 0;
  padding: 0 0 0 var(--space-3);
  border-left: 3px solid var(--signal-500);
  font-family: var(--font-serif);
  font-style: italic;
  font-size: clamp(19px, 2.4vw, 26px);
  line-height: 1.65;
  color: var(--abyss-900);
  max-width: 26em;
}

/* ---------- 主题带 ---------- */
.page-about .theme-band {
  margin-block: var(--space-5);
}

.page-about .theme-band__title {
  font-family: var(--font-num);
  font-weight: 700;
  letter-spacing: .06em;
  font-size: clamp(18px, 2.6vw, 28px);
  font-variant-numeric: tabular-nums;
}

/* ---------- 版本时间轴 ---------- */
.page-about .about-versions {
  padding-top: var(--space-4);
}

.page-about .ver-track {
  list-style: none;
  margin: var(--space-4) 0 0;
  padding: 0 0 var(--space-3);
  display: flex;
  gap: var(--space-3);
  overflow-x: auto;
  scroll-snap-type: x proximity;
  -webkit-overflow-scrolling: touch;
  scrollbar-width: thin;
}

.page-about .ver-node {
  flex: 0 0 min(300px, 78vw);
  scroll-snap-align: start;
  position: relative;
  padding: 44px var(--space-3) var(--space-3);
  border: 1px solid var(--hairline-light);
  border-radius: var(--radius-lg);
  background: linear-gradient(180deg, #ffffff 0%, var(--paper-50) 100%);
  box-shadow: var(--shadow-soft);
}

.page-about .ver-node::before {
  content: "";
  position: absolute;
  top: 24px;
  left: 0;
  right: 0;
  height: 2px;
  background: var(--chart-300);
}

.page-about .ver-node::after {
  content: "";
  position: absolute;
  top: 19px;
  left: var(--space-3);
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--signal-500);
  box-shadow: 0 0 0 5px rgba(35, 224, 196, .20);
}

.page-about .ver-node__tag {
  font-family: var(--font-num);
  font-weight: 700;
  font-size: 15px;
  letter-spacing: .12em;
  color: var(--sunset-500);
  margin: 0 0 6px;
  font-variant-numeric: tabular-nums;
}

.page-about .ver-node__title {
  font-family: var(--font-serif);
  font-size: 19px;
  font-weight: 600;
  line-height: 1.45;
  margin: 0 0 8px;
  color: var(--abyss-900);
}

.page-about .ver-node__desc {
  margin: 0;
  font-size: 14px;
  line-height: 1.8;
  color: var(--chart-600);
}

.page-about .ver-node__more {
  margin: var(--space-2) 0 0;
  padding-top: var(--space-2);
  border-top: 1px dashed var(--hairline-light);
  font-size: 13px;
  line-height: 1.75;
  color: var(--abyss-700);
  transition: max-height .25s var(--ease-out), opacity .25s var(--ease-out),
              margin .25s var(--ease-out), padding .25s var(--ease-out);
}

@media (hover: hover) and (min-width: 900px) {
  .page-about .ver-node__more {
    max-height: 0;
    opacity: 0;
    overflow: hidden;
    margin-top: 0;
    padding-top: 0;
    border-top-color: transparent;
  }

  .page-about .ver-node:hover .ver-node__more,
  .page-about .ver-node:focus-within .ver-node__more {
    max-height: 140px;
    opacity: 1;
    margin-top: var(--space-2);
    padding-top: var(--space-2);
    border-top-color: var(--hairline-light);
  }
}

/* ---------- 图片容器 ---------- */
.page-about .about-figure {
  margin-block: var(--space-4);
}

.page-about .about-figure--partners {
  margin-top: 0;
}

/* ---------- 团队分工 ---------- */
.page-about .roles {
  margin: var(--space-4) 0 0;
  display: grid;
  gap: 1px;
  background: var(--hairline-light);
  border: 1px solid var(--hairline-light);
  border-radius: var(--radius-lg);
  overflow: hidden;
}

.page-about .role {
  background: var(--paper-50);
  padding: var(--space-3);
  display: grid;
  gap: 6px;
  transition: background .2s var(--ease-out);
}

.page-about .role:hover {
  background: #ffffff;
}

.page-about .role__name {
  margin: 0;
  font-family: var(--font-serif);
  font-size: 17px;
  font-weight: 600;
  color: var(--abyss-900);
  line-height: 1.5;
}

.page-about .role__desc {
  margin: 0;
  font-size: 14px;
  line-height: 1.85;
  color: var(--chart-600);
}

@media (min-width: 800px) {
  .page-about .role {
    grid-template-columns: 230px minmax(0, 1fr);
    gap: var(--space-3);
    align-items: baseline;
    padding: var(--space-3) var(--space-4);
  }
}

/* ---------- 流程 ---------- */
.page-about .flow-svg {
  display: block;
  width: 100%;
  height: 56px;
  margin: var(--space-4) 0 var(--space-4);
}

.page-about .flow-svg__track {
  stroke: var(--chart-300);
  stroke-width: 1.5;
  stroke-dasharray: 8 10;
}

.page-about .flow-svg__tick {
  stroke: var(--signal-500);
  stroke-width: 3;
  stroke-linecap: round;
}

.page-about .flow {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: var(--space-3);
}

@media (min-width: 880px) {
  .page-about .flow {
    grid-template-columns: repeat(5, minmax(0, 1fr));
  }
}

.page-about .flow-step {
  padding: var(--space-3);
  background: #ffffff;
  border: 1px solid var(--hairline-light);
  border-radius: var(--radius-md);
  border-top: 3px solid var(--signal-100);
  transition: border-top-color .2s var(--ease-out);
}

.page-about .flow-step:hover {
  border-top-color: var(--signal-500);
}

.page-about .flow-step__index {
  font-family: var(--font-num);
  font-weight: 700;
  font-size: 13px;
  letter-spacing: .12em;
  color: var(--sunset-500);
  font-variant-numeric: tabular-nums;
}

.page-about .flow-step__title {
  font-family: var(--font-serif);
  font-size: 16px;
  font-weight: 600;
  margin: 6px 0 8px;
  color: var(--abyss-900);
  line-height: 1.5;
}

.page-about .flow-step__desc {
  margin: 0;
  font-size: 13px;
  line-height: 1.8;
  color: var(--chart-600);
}

/* ---------- 合作 ---------- */
.page-about .about-partners__text p {
  font-size: 15px;
  line-height: 1.9;
  color: var(--ink-900);
  margin: var(--space-3) 0 0;
}

.page-about .about-partners__link {
  margin-top: var(--space-3);
}

/* ---------- 覆盖范围 ---------- */
.page-about .coverage {
  position: relative;
  padding: var(--space-5) var(--space-3);
  border-radius: var(--radius-xl);
  background:
    radial-gradient(90% 130% at 88% -6%, rgba(35, 224, 196, .20), transparent 60%),
    radial-gradient(70% 110% at 0% 110%, rgba(255, 122, 69, .16), transparent 62%),
    var(--abyss-900);
  color: var(--paper-50);
  overflow: hidden;
}

@media (min-width: 760px) {
  .page-about .coverage {
    padding: var(--space-5) var(--space-5);
  }
}

.page-about .coverage .eyebrow {
  color: var(--signal-500);
}

.page-about .coverage__title {
  font-family: var(--font-serif);
  font-weight: 600;
  font-size: clamp(22px, 3vw, 32px);
  line-height: 1.4;
  margin: 8px 0 0;
  color: var(--paper-50);
  max-width: 18em;
}

.page-about .coverage__list {
  list-style: none;
  margin: var(--space-4) 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: var(--space-4) var(--space-3);
}

@media (min-width: 880px) {
  .page-about .coverage__list {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

.page-about .coverage__num {
  display: block;
  font-family: var(--font-num);
  font-weight: 700;
  font-size: clamp(32px, 4.8vw, 54px);
  line-height: 1;
  color: var(--signal-500);
  font-variant-numeric: tabular-nums;
}

.page-about .coverage__label {
  display: block;
  margin-top: var(--space-1);
  font-size: 13px;
  line-height: 1.7;
  color: var(--chart-300);
}

.page-about .coverage__note {
  margin: var(--space-4) 0 0;
  padding-top: var(--space-3);
  border-top: 1px solid var(--hairline-dark);
  font-size: 14px;
  line-height: 1.85;
  color: var(--chart-300);
  max-width: 46em;
}

/* ---------- 后续入口 ---------- */
.page-about .next-list {
  list-style: none;
  margin: var(--space-4) 0 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--hairline-light);
  border: 1px solid var(--hairline-light);
  border-radius: var(--radius-lg);
  overflow: hidden;
}

.page-about .next-item {
  background: var(--paper-50);
  padding: var(--space-3) var(--space-3);
  display: grid;
  gap: 6px;
  transition: background .2s var(--ease-out);
}

.page-about .next-item:hover {
  background: #ffffff;
}

.page-about .next-item__link {
  justify-self: start;
  font-family: var(--font-serif);
  font-size: 18px;
  font-weight: 600;
  line-height: 1.5;
  color: var(--abyss-900);
  text-decoration: none;
  border-bottom: 2px solid transparent;
  padding-bottom: 2px;
  transition: border-color .2s var(--ease-out), color .2s var(--ease-out);
}

.page-about .next-item__link:hover,
.page-about .next-item__link:focus-visible {
  border-bottom-color: var(--signal-500);
  color: var(--abyss-700);
}

.page-about .next-item__desc {
  margin: 0;
  font-size: 14px;
  line-height: 1.85;
  color: var(--chart-600);
}

@media (min-width: 800px) {
  .page-about .next-item {
    grid-template-columns: 260px minmax(0, 1fr);
    gap: var(--space-3);
    align-items: baseline;
    padding: var(--space-3) var(--space-4);
  }
}

/* ---------- 动效降级 ---------- */
@media (prefers-reduced-motion: reduce) {
  .page-about .ver-node__more,
  .page-about .role,
  .page-about .flow-step,
  .page-about .next-item,
  .page-about .next-item__link {
    transition: none !important;
  }
}