.page-about {
  --about-gap: clamp(28px, 5vw, 64px);
  --about-side: 216px;
  --about-hero-pad: clamp(30px, 6vw, 74px);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  padding: var(--about-hero-pad) 0 clamp(26px, 4.5vw, 52px);
  overflow: hidden;
  border-bottom: 1px solid var(--line-soft);
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  background:
    radial-gradient(760px 400px at 6% -22%, rgba(47, 123, 255, .24), transparent 68%),
    radial-gradient(620px 340px at 94% 6%, rgba(35, 230, 208, .13), transparent 72%);
}

.page-about .about-hero > .container {
  position: relative;
  z-index: 1;
}

.page-about .about-hero__crumb {
  margin-bottom: clamp(20px, 3vw, 32px);
}

.page-about .about-hero__kicker {
  margin: 0;
  color: var(--cyan);
}

.page-about .about-hero__title {
  margin: 14px 0 20px;
  max-width: 17ch;
  font-family: var(--font-cn);
  font-weight: 300;
  font-size: clamp(34px, 6.4vw, 78px);
  line-height: 1.05;
  letter-spacing: .01em;
  color: var(--text);
  text-wrap: balance;
}

.page-about .about-hero__lead {
  max-width: 46ch;
  margin: 0;
  color: var(--text-soft);
  font-size: clamp(15px, 1.4vw, 16.5px);
  line-height: 1.8;
}

.page-about .about-hero__stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
  margin-top: clamp(28px, 4vw, 46px);
}

.page-about .about-stat {
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding: 16px 18px;
  border: 1px solid var(--line);
  border-radius: var(--r-md);
  background: linear-gradient(160deg, rgba(13, 20, 32, .92), rgba(11, 17, 27, .82));
}

.page-about .about-stat__num {
  font-size: clamp(24px, 3.2vw, 32px);
  line-height: 1;
  color: var(--text);
  letter-spacing: -.02em;
}

.page-about .about-stat__label {
  font-size: 12.5px;
  color: var(--muted);
  letter-spacing: .04em;
}

/* ---------- 主布局：左侧索引 + 右侧叙述列 ---------- */
.page-about .about-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(24px, 4vw, 52px);
  padding-top: clamp(32px, 6vw, 72px);
  padding-bottom: clamp(40px, 8vw, 96px);
}

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

.page-about .about-index__list {
  display: flex;
  gap: 8px;
  margin: 10px 0 0;
  padding: 0 0 6px;
  list-style: none;
  overflow-x: auto;
  scrollbar-width: none;
  -ms-overflow-style: none;
}

.page-about .about-index__list::-webkit-scrollbar {
  display: none;
}

.page-about .about-index__item {
  flex: 0 0 auto;
}

.page-about .about-index .toc__link {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 9px 14px;
  border: 1px solid var(--line);
  border-radius: var(--pill);
  background: rgba(11, 17, 27, .7);
  color: var(--text-soft);
  font-size: 13px;
  text-decoration: none;
  white-space: nowrap;
  transition: border-color var(--dur) var(--ease), color var(--dur) var(--ease), background-color var(--dur) var(--ease);
}

.page-about .about-index .toc__link:hover {
  color: var(--cyan);
  border-color: rgba(35, 230, 208, .45);
}

.page-about .about-index .toc__link[data-active="true"] {
  color: var(--text);
  border-color: rgba(47, 123, 255, .6);
  background: rgba(47, 123, 255, .14);
  box-shadow: inset 0 0 0 1px rgba(47, 123, 255, .25);
}

.page-about .about-index .toc__index {
  font-size: 11px;
  letter-spacing: .16em;
  color: var(--blue);
}

.page-about .about-index .toc__title {
  margin: 0;
  font-size: 12px;
  letter-spacing: .22em;
  text-transform: uppercase;
  color: var(--muted);
}

/* ---------- 章节块 ---------- */
.page-about .about-stream {
  min-width: 0;
  display: flex;
  flex-direction: column;
  gap: clamp(44px, 7vw, 92px);
}

.page-about .about-block {
  scroll-margin-top: calc(var(--header-h) + 32px);
}

.page-about .about-block__head {
  margin-bottom: 18px;
}

.page-about .about-block__num {
  display: block;
  margin-bottom: 8px;
  font-size: clamp(30px, 4.6vw, 50px);
  line-height: 1;
  letter-spacing: -.03em;
  color: rgba(47, 123, 255, .34);
}

.page-about .about-block__title {
  margin: 0;
  font-family: var(--font-cn);
  font-weight: 400;
  font-size: clamp(22px, 3vw, 32px);
  line-height: 1.25;
  letter-spacing: .005em;
  color: var(--text);
}

.page-about .about-block__lead {
  margin: 0 0 22px;
  color: var(--text-soft);
}

.page-about .about-block__body p {
  margin: 0 0 16px;
  color: var(--text-soft);
}

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

.page-about .about-block .prose {
  max-width: 40ch;
}

.page-about .about-block .prose p {
  margin: 0 0 16px;
}

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

.page-about .about-block .img-frame {
  margin: clamp(22px, 3.4vw, 34px) 0;
}

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

.page-about .about-versions__figure {
  aspect-ratio: 16 / 7;
}

.page-about .about-team__figure {
  aspect-ratio: 3 / 2;
}

/* ---------- 版本时间轴 ---------- */
.page-about .about-timeline {
  list-style: none;
  margin: 0;
  padding: 0;
  position: relative;
}

.page-about .about-timeline::before {
  content: "";
  position: absolute;
  left: 15px;
  top: 10px;
  bottom: 10px;
  width: 1px;
  background: linear-gradient(180deg, rgba(35, 230, 208, .5), rgba(47, 123, 255, .35), rgba(255, 166, 43, .45));
}

.page-about .about-timeline__item {
  position: relative;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 8px;
  padding: 0 0 26px 44px;
}

.page-about .about-timeline__item:last-child {
  padding-bottom: 0;
}

.page-about .about-timeline__item::before {
  content: "";
  position: absolute;
  left: 9px;
  top: 6px;
  width: 13px;
  height: 13px;
  border-radius: 50%;
  background: var(--ink);
  border: 2px solid var(--cyan);
  box-shadow: 0 0 0 4px rgba(35, 230, 208, .1);
}

.page-about .about-timeline__item:nth-child(6)::before {
  border-color: var(--blue);
  box-shadow: 0 0 0 4px rgba(47, 123, 255, .14);
}

.page-about .about-timeline__item:nth-child(7)::before {
  border-color: var(--amber);
  box-shadow: 0 0 0 4px rgba(255, 166, 43, .14);
}

.page-about .about-timeline__marker {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-wrap: wrap;
}

.page-about .about-timeline__ver {
  font-size: clamp(19px, 2.4vw, 24px);
  letter-spacing: -.02em;
  color: var(--text);
}

.page-about .about-timeline__title {
  margin: 6px 0 6px;
  font-size: 17px;
  font-weight: 500;
  color: var(--text);
  letter-spacing: .01em;
}

.page-about .about-timeline__content p {
  margin: 0;
  color: var(--text-soft);
  font-size: 15px;
  line-height: 1.75;
  max-width: 40ch;
}

/* ---------- 团队 ---------- */
.page-about .about-team__cards {
  margin-top: clamp(18px, 3vw, 28px);
}

.page-about .about-team__card {
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding: 20px;
  background: linear-gradient(165deg, rgba(13, 20, 32, .94), rgba(11, 17, 27, .8));
}

.page-about .about-team__count {
  font-size: 32px;
  line-height: 1;
  letter-spacing: -.03em;
  color: var(--blue);
}

.page-about .about-team__card .card__meta {
  margin: 0;
  font-size: 12px;
  letter-spacing: .04em;
  color: var(--muted);
}

.page-about .about-team__card p:not(.card__meta) {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.72;
  color: var(--text-soft);
}

.page-about .about-flow {
  margin-top: clamp(20px, 3vw, 30px);
  padding: 22px;
}

.page-about .about-flow__title {
  margin: 0 0 16px;
  font-size: 16px;
  font-weight: 500;
  letter-spacing: .04em;
  color: var(--text);
}

.page-about .about-flow__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.page-about .about-flow__step {
  display: grid;
  grid-template-columns: 34px minmax(0, 1fr);
  gap: 12px;
  align-items: start;
  padding: 11px 0;
  border-top: 1px solid var(--line-soft);
}

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

.page-about .about-flow__idx {
  font-size: 12px;
  letter-spacing: .1em;
  color: var(--cyan);
  padding-top: 3px;
}

.page-about .about-flow__step strong {
  display: block;
  font-size: 14.5px;
  font-weight: 500;
  color: var(--text);
  margin-bottom: 3px;
}

.page-about .about-flow__step span:not(.about-flow__idx) {
  display: block;
  font-size: 14px;
  line-height: 1.7;
  color: var(--text-soft);
}

/* ---------- 数据来源 ---------- */
.page-about .about-sources {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 14px;
}

.page-about .about-source {
  display: flex;
  flex-direction: column;
  gap: 10px;
  align-items: flex-start;
  padding: 20px;
  border: 1px solid var(--line);
  border-radius: var(--r-lg);
  background:
    linear-gradient(150deg, rgba(22, 38, 58, .5), rgba(11, 17, 27, .9) 55%);
  border-top: 2px solid rgba(47, 123, 255, .5);
}

.page-about .about-source:nth-child(2) {
  border-top-color: rgba(255, 166, 43, .6);
}

.page-about .about-source:nth-child(3) {
  border-top-color: rgba(35, 230, 208, .55);
}

.page-about .about-source__kicker {
  color: var(--muted);
}

.page-about .about-source__title {
  margin: 0;
  font-size: 18px;
  font-weight: 500;
  letter-spacing: .01em;
  color: var(--text);
}

.page-about .about-source p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.75;
  color: var(--text-soft);
}

.page-about .about-sources__note {
  margin-top: clamp(18px, 3vw, 26px);
  padding: 22px;
  border-left: 3px solid var(--amber);
}

.page-about .about-sources__note-title {
  margin: 0 0 12px;
  font-size: 16px;
  font-weight: 500;
  color: var(--amber);
  letter-spacing: .02em;
}

.page-about .about-sources__note p {
  margin: 0 0 12px;
  font-size: 15px;
  line-height: 1.78;
  color: var(--text-soft);
  max-width: 42ch;
}

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

/* ---------- 三条承诺 ---------- */
.page-about .about-promises {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 14px;
}

.page-about .about-promise {
  position: relative;
  padding: 22px 20px 20px;
  border-radius: var(--r-lg);
  border: 1px solid var(--line);
  background: rgba(11, 17, 27, .78);
  overflow: hidden;
}

.page-about .about-promise::after {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  width: 4px;
  height: 100%;
  background: var(--cyan);
}

.page-about .about-promise--blue::after {
  background: var(--blue);
}

.page-about .about-promise--amber::after {
  background: var(--amber);
}

.page-about .about-promise__idx {
  display: block;
  margin-bottom: 8px;
  font-size: 12px;
  letter-spacing: .2em;
  color: var(--muted);
}

.page-about .about-promise__title {
  margin: 0 0 8px;
  font-size: clamp(20px, 2.6vw, 26px);
  font-weight: 300;
  letter-spacing: .01em;
  color: var(--text);
}

.page-about .about-promise p {
  margin: 0;
  font-size: 14.8px;
  line-height: 1.78;
  color: var(--text-soft);
  max-width: 40ch;
}

/* ---------- 生态与合作 ---------- */
.page-about .about-partners {
  margin-bottom: clamp(20px, 3vw, 30px);
}

.page-about .about-partner {
  padding: 20px;
  background: linear-gradient(165deg, rgba(13, 20, 32, .9), rgba(11, 17, 27, .78));
}

.page-about .about-partner .card__title {
  margin: 0 0 8px;
  font-size: 16px;
  font-weight: 500;
  color: var(--text);
}

.page-about .about-partner p {
  margin: 0;
  font-size: 14.2px;
  line-height: 1.75;
  color: var(--text-soft);
}

.page-about .about-open {
  padding: 24px 22px;
  border-radius: var(--r-lg);
  border: 1px solid rgba(35, 230, 208, .28);
  background:
    radial-gradient(520px 220px at 8% 0%, rgba(35, 230, 208, .12), transparent 70%),
    rgba(11, 17, 27, .85);
}

.page-about .about-open__title {
  margin: 0 0 10px;
  font-size: clamp(18px, 2.3vw, 22px);
  font-weight: 400;
  color: var(--text);
  letter-spacing: .01em;
}

.page-about .about-open p {
  margin: 0 0 18px;
  font-size: 15px;
  line-height: 1.78;
  color: var(--text-soft);
  max-width: 42ch;
}

/* ---------- 收尾 ---------- */
.page-about .about-closing {
  border-top: 1px solid var(--line-soft);
  background:
    radial-gradient(900px 380px at 78% 110%, rgba(47, 123, 255, .16), transparent 70%),
    var(--ink);
  padding: clamp(40px, 7vw, 88px) 0 clamp(48px, 8vw, 96px);
}

.page-about .about-closing__inner {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(24px, 4vw, 48px);
  align-items: center;
}

.page-about .about-closing__figure {
  width: min(100%, 340px);
  aspect-ratio: 1 / 1;
  margin: 0;
}

.page-about .about-closing__figure img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.page-about .about-closing__text .index-label {
  color: var(--cyan);
}

.page-about .about-closing__title {
  margin: 12px 0 14px;
  font-family: var(--font-cn);
  font-weight: 300;
  font-size: clamp(26px, 4.2vw, 46px);
  line-height: 1.14;
  letter-spacing: .005em;
  color: var(--text);
  max-width: 20ch;
}

.page-about .about-closing__lead {
  margin: 0 0 22px;
  max-width: 44ch;
  color: var(--text-soft);
  font-size: 15.5px;
  line-height: 1.8;
}

/* ---------- 媒体查询 ---------- */
@media (min-width: 640px) {
  .page-about .about-hero__stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 12px;
  }

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

  .page-about .about-source:nth-child(3) {
    grid-column: span 2;
  }

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

@media (min-width: 900px) {
  .page-about .about-layout {
    grid-template-columns: var(--about-side) minmax(0, 1fr);
    gap: clamp(36px, 5vw, 72px);
  }

  .page-about .about-index {
    position: sticky;
    top: calc(var(--header-h) + 30px);
    align-self: start;
  }

  .page-about .about-index__list {
    display: block;
    overflow: visible;
    padding-bottom: 0;
  }

  .page-about .about-index__item {
    display: block;
    margin-bottom: 4px;
  }

  .page-about .about-index .toc__link {
    display: flex;
    width: 100%;
    padding: 9px 12px;
    border-color: transparent;
    background: transparent;
    border-radius: var(--r-sm);
    border-left: 2px solid transparent;
  }

  .page-about .about-index .toc__link[data-active="true"] {
    border-left-color: var(--blue);
    border-radius: 0 var(--r-sm) var(--r-sm) 0;
    box-shadow: none;
  }

  .page-about .about-timeline__item {
    grid-template-columns: minmax(0, 1fr);
    padding-left: 52px;
  }

  .page-about .about-timeline::before {
    left: 17px;
  }

  .page-about .about-timeline__item::before {
    left: 11px;
  }

  .page-about .about-closing__inner {
    grid-template-columns: minmax(0, 320px) minmax(0, 1fr);
  }

  .page-about .about-closing__figure {
    width: 100%;
  }
}

@media (min-width: 1100px) {
  .page-about .about-sources {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .page-about .about-source:nth-child(3) {
    grid-column: auto;
  }

  .page-about .about-timeline__item {
    grid-template-columns: 170px minmax(0, 1fr);
    gap: 20px;
    padding-left: 52px;
  }

  .page-about .about-timeline__marker {
    flex-direction: column;
    align-items: flex-start;
    gap: 8px;
  }

  .page-about .about-timeline__title {
    margin-top: 0;
  }
}

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