.page-about {
  position: relative;
  overflow-x: clip;
}

.page-about::before {
  content: "";
  position: absolute;
  inset: 0 0 auto 0;
  height: 620px;
  pointer-events: none;
  z-index: 0;
  background:
    radial-gradient(620px 320px at 10% 0%, rgba(34, 227, 210, .15), transparent 70%),
    radial-gradient(560px 300px at 90% 6%, rgba(255, 138, 30, .12), transparent 72%);
}

.page-about > .qb-section {
  position: relative;
  z-index: 1;
}

.page-about .about-link {
  color: var(--qb-cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(34, 227, 210, .4);
  transition: border-color 160ms var(--qb-speed), color 160ms var(--qb-speed);
}

.page-about .about-link:hover,
.page-about .about-link:focus-visible {
  color: var(--qb-white);
  border-bottom-color: var(--qb-orange);
}

/* ---------- 首屏：目录式声明 ---------- */

.page-about .about-intro {
  padding-top: calc(var(--qb-header-h) + 28px);
}

.page-about .about-intro__kicker {
  margin-top: 22px;
  color: var(--qb-cyan);
}

.page-about .about-intro__title {
  margin: 16px 0 0;
  font-size: clamp(34px, 7.4vw, 76px);
  line-height: 1.08;
  max-width: 22ch;
}

.page-about .about-intro__lead {
  margin-top: 22px;
  max-width: 62ch;
  color: var(--qb-mist);
}

.page-about .about-stats {
  list-style: none;
  margin: 40px 0 0;
  padding: 1px 0 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--qb-line);
  border-top: 1px solid var(--qb-line);
  border-bottom: 1px solid var(--qb-line);
}

.page-about .about-stats__item {
  background: var(--qb-night);
  padding: 18px 14px;
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.page-about .about-stats__item .qb-stat__value {
  color: var(--qb-white);
  font-size: clamp(24px, 4.4vw, 34px);
}

.page-about .about-stats__item .qb-stat__label {
  color: var(--qb-mist);
  font-size: 13px;
  letter-spacing: .02em;
}

.page-about .about-index {
  margin-top: 46px;
}

.page-about .about-index__title {
  margin-bottom: 12px;
}

.page-about .about-index__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: 1fr;
  gap: 1px;
  background: var(--qb-line);
  border-top: 1px solid var(--qb-line);
  border-bottom: 1px solid var(--qb-line);
}

.page-about .about-index__link {
  display: flex;
  align-items: baseline;
  gap: 12px;
  padding: 14px 12px;
  background: var(--qb-night);
  color: var(--qb-white);
  text-decoration: none;
  border-left: 2px solid transparent;
  transition: background 160ms var(--qb-speed), border-color 160ms var(--qb-speed), transform 160ms var(--qb-speed);
}

.page-about .about-index__link .qb-toc__index {
  color: var(--qb-cyan);
  flex: 0 0 auto;
}

.page-about .about-index__text {
  font-size: 15px;
  line-height: 1.5;
}

.page-about .about-index__link:hover,
.page-about .about-index__link:focus-visible {
  background: var(--qb-board);
  border-left-color: var(--qb-orange);
  transform: translateX(2px);
}

.page-about .about-index__link[aria-current="true"],
.page-about .about-index__link[aria-current="location"] {
  border-left-color: var(--qb-cyan);
  background: var(--qb-board);
}

/* ---------- 章节通用标题 ---------- */

.page-about .about-head {
  max-width: 68ch;
}

.page-about .about-head__title {
  margin: 12px 0 0;
  font-size: clamp(26px, 4.4vw, 40px);
  line-height: 1.2;
}

.page-about .about-head__lead {
  margin: 14px 0 0;
  color: var(--qb-mist);
}

/* ---------- 时间线 ---------- */

.page-about .about-timeline__media {
  margin: 34px 0 0;
}

.page-about .about-years {
  list-style: none;
  margin: 40px 0 0;
  padding: 0;
}

.page-about .about-year {
  position: relative;
  padding: 24px 0 24px 26px;
  border-left: 1px solid var(--qb-line);
}

.page-about .about-year + .about-year {
  border-top: 1px solid rgba(22, 34, 74, .7);
}

.page-about .about-year::before {
  content: "";
  position: absolute;
  left: -4.5px;
  top: 31px;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--qb-cyan);
  box-shadow: 0 0 0 4px rgba(34, 227, 210, .14);
}

.page-about .about-year__mark {
  display: flex;
  align-items: baseline;
  gap: 10px;
}

.page-about .about-year__num {
  color: var(--qb-cyan);
  font-size: 24px;
  letter-spacing: .02em;
}

.page-about .about-year__phase {
  font-size: 12px;
  letter-spacing: .12em;
  color: var(--qb-mist);
  border: 1px solid var(--qb-line);
  padding: 2px 8px;
}

.page-about .about-year__body {
  margin-top: 12px;
}

.page-about .about-year__body h3 {
  margin: 0 0 8px;
}

.page-about .about-year__body p {
  margin: 0;
  color: var(--qb-mist);
  max-width: 64ch;
}

/* ---------- 团队 ---------- */

.page-about .about-team__split {
  display: grid;
  grid-template-columns: 1fr;
  gap: 30px;
  margin-top: 34px;
}

.page-about .about-team__subhead,
.page-about .about-team__flowhead {
  margin: 0 0 18px;
}

.page-about .about-team__flowhead {
  margin-top: 44px;
}

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

.page-about .about-bars {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 20px;
}

.page-about .about-bar__head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 8px;
}

.page-about .about-bar__count {
  color: var(--qb-white);
  font-size: 14px;
}

.page-about .about-bar__track {
  height: 8px;
  background: var(--qb-board);
  border: 1px solid var(--qb-line);
  overflow: hidden;
}

.page-about .about-bar__fill {
  display: block;
  height: 100%;
  transition: transform 200ms var(--qb-speed);
  transform-origin: left center;
}

.page-about .about-bar--ops .about-bar__fill { width: 31.6%; background: linear-gradient(90deg, var(--qb-cyan), rgba(34, 227, 210, .5)); }
.page-about .about-bar--video .about-bar__fill { width: 28.9%; background: linear-gradient(90deg, var(--qb-orange), rgba(255, 138, 30, .5)); }
.page-about .about-bar--data .about-bar__fill { width: 23.7%; background: linear-gradient(90deg, var(--qb-gold), rgba(255, 209, 102, .5)); }
.page-about .about-bar--tech .about-bar__fill { width: 15.8%; background: linear-gradient(90deg, var(--qb-mist), rgba(168, 182, 217, .4)); }

.page-about .about-bar__note {
  margin: 8px 0 0;
  font-size: 13px;
  line-height: 1.6;
  color: var(--qb-mist);
}

.page-about .about-bar:hover .about-bar__fill {
  transform: scaleX(1.02);
}

.page-about .about-bar:hover .about-bar__note {
  color: var(--qb-white);
}

.page-about .about-flow {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: 1fr;
  gap: 1px;
  background: var(--qb-line);
  border: 1px solid var(--qb-line);
}

.page-about .about-flow__step {
  background: var(--qb-board);
  padding: 18px 16px;
  transition: background 160ms var(--qb-speed);
}

.page-about .about-flow__step:hover {
  background: var(--qb-lift);
}

.page-about .about-flow__num {
  display: block;
  font-family: var(--qb-mono);
  font-size: 12px;
  letter-spacing: .12em;
  color: var(--qb-orange);
}

.page-about .about-flow__name {
  margin: 8px 0 4px;
  font-weight: 700;
  color: var(--qb-white);
}

.page-about .about-flow__desc {
  margin: 0;
  font-size: 13px;
  line-height: 1.65;
  color: var(--qb-mist);
}

/* ---------- 三条内容线 ---------- */

.page-about .about-line-list {
  margin-top: 34px;
  border-top: 1px solid var(--qb-line);
}

.page-about .about-line {
  display: grid;
  grid-template-columns: 1fr;
  gap: 14px;
  padding: 26px 0;
  border-bottom: 1px solid var(--qb-line);
  transition: background 160ms var(--qb-speed);
}

.page-about .about-line__num {
  font-size: 30px;
  color: rgba(34, 227, 210, .55);
  line-height: 1;
}

.page-about .about-line__main h3 {
  margin: 0 0 10px;
}

.page-about .about-line__main p {
  margin: 0;
  color: var(--qb-mist);
  max-width: 60ch;
}

.page-about .about-line__keys {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 8px;
}

.page-about .about-line__keys li {
  display: flex;
  align-items: baseline;
  gap: 8px;
  font-size: 13px;
  color: var(--qb-mist);
  border-left: 1px solid var(--qb-line);
  padding-left: 10px;
}

.page-about .about-line__keys .qb-num {
  color: var(--qb-white);
  font-size: 16px;
}

.page-about .about-lines__foot {
  margin: 26px 0 0;
  color: var(--qb-mist);
  font-size: 14px;
}

/* ---------- 区域 ---------- */

.page-about .about-region__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 30px;
  margin-top: 34px;
}

.page-about .about-dots {
  display: grid;
  grid-template-columns: repeat(10, minmax(0, 1fr));
  gap: 10px;
  padding: 22px;
  background: var(--qb-board);
  border: 1px solid var(--qb-line);
}

.page-about .about-dots span {
  display: block;
  aspect-ratio: 1 / 1;
  border-radius: 50%;
  background: var(--qb-line);
  transition: transform 160ms var(--qb-speed);
}

.page-about .about-dots span.is-core {
  background: var(--qb-cyan);
  box-shadow: 0 0 10px rgba(34, 227, 210, .4);
}

.page-about .about-dots span.is-mid {
  background: var(--qb-orange);
  opacity: .78;
}

.page-about .about-dots span.is-far {
  background: rgba(168, 182, 217, .28);
}

.page-about .about-dots span:hover {
  transform: scale(1.45);
}

.page-about .about-legend {
  list-style: none;
  margin: 18px 0 0;
  padding: 0;
  display: grid;
  gap: 10px;
}

.page-about .about-legend__item {
  display: flex;
  align-items: baseline;
  gap: 10px;
  font-size: 13px;
  color: var(--qb-mist);
}

.page-about .about-legend__dot {
  flex: 0 0 auto;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  transform: translateY(1px);
}

.page-about .about-legend__dot--core { background: var(--qb-cyan); }
.page-about .about-legend__dot--mid { background: var(--qb-orange); }
.page-about .about-legend__dot--far { background: rgba(168, 182, 217, .5); }

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

.page-about .about-region__text p {
  margin: 0 0 16px;
  color: var(--qb-mist);
}

/* ---------- 社群共建 ---------- */

.page-about .about-build__grid {
  margin-top: 34px;
}

.page-about .about-build__card .qb-card__head {
  margin-bottom: 8px;
}

.page-about .about-build__card .qb-card__head .qb-index {
  color: var(--qb-orange);
}

.page-about .about-build__card .qb-card__body p {
  margin: 0;
  color: var(--qb-mist);
}

.page-about .about-build__foot {
  margin: 26px 0 0;
  color: var(--qb-mist);
  font-size: 14px;
}

/* ---------- 内容标准 ---------- */

.page-about .about-rules {
  list-style: none;
  margin: 34px 0 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--qb-line);
  border-top: 1px solid var(--qb-line);
  border-bottom: 1px solid var(--qb-line);
}

.page-about .about-rule {
  background: var(--qb-night);
  padding: 20px 0;
  display: grid;
  gap: 10px;
}

.page-about .about-rule p {
  margin: 0;
  color: var(--qb-mist);
  max-width: 68ch;
}

/* ---------- 结尾跳转 ---------- */

.page-about .about-next__card {
  padding: 28px 22px;
  background: linear-gradient(135deg, var(--qb-board), var(--qb-night) 65%);
}

.page-about .about-next__kicker {
  color: var(--qb-cyan);
}

.page-about .about-next__title {
  margin: 12px 0 20px;
}

.page-about .about-next__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

/* ---------- 媒体查询 ---------- */

@media (min-width: 640px) {
  .page-about .about-stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

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

  .page-about .about-index__link {
    padding: 16px 14px;
  }

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

  .page-about .about-rule {
    grid-template-columns: 132px minmax(0, 1fr);
    align-items: baseline;
    gap: 20px;
  }
}

@media (min-width: 900px) {
  .page-about .about-year {
    display: grid;
    grid-template-columns: 136px minmax(0, 1fr);
    gap: 32px;
    padding: 28px 0 28px 32px;
  }

  .page-about .about-year__mark {
    flex-direction: column;
    align-items: flex-start;
    gap: 8px;
    position: sticky;
    top: calc(var(--qb-header-h) + 24px);
  }

  .page-about .about-year__num {
    font-size: 34px;
  }

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

  .page-about .about-year::before {
    top: 36px;
  }

  .page-about .about-team__split {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, .95fr);
    align-items: start;
    gap: 44px;
  }

  .page-about .about-flow {
    grid-template-columns: repeat(5, minmax(0, 1fr));
  }

  .page-about .about-line {
    grid-template-columns: 84px minmax(0, 1fr) 220px;
    gap: 30px;
    align-items: start;
    padding: 30px 0;
  }

  .page-about .about-line__num {
    font-size: 40px;
  }

  .page-about .about-region__grid {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
    gap: 44px;
    align-items: start;
  }

  .page-about .about-next__card {
    padding: 40px 36px;
  }
}

@media (min-width: 1180px) {
  .page-about .about-index__list {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .page-about .about-region__grid {
    grid-template-columns: minmax(0, .95fr) minmax(0, 1.05fr);
  }
}

.page-about img {
  max-width: 100%;
  height: auto;
  object-fit: cover;
}
<<<END>>>