.page-about {
  background: var(--night);
  color: var(--white);
  overflow-x: hidden;
}

.page-about .about-hero {
  position: relative;
  padding: clamp(24px, 5vw, 64px) 0 clamp(30px, 5vw, 56px);
  border-bottom: 1px solid var(--line);
  background-image:
    linear-gradient(180deg, rgba(20, 27, 77, 0.85), rgba(11, 16, 51, 0) 78%),
    repeating-linear-gradient(90deg, rgba(40, 51, 110, 0.42) 0 1px, transparent 1px 108px),
    repeating-linear-gradient(0deg, rgba(40, 51, 110, 0.28) 0 1px, transparent 1px 108px);
  background-position: 0 0, 0 0, 0 0;
}

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

.page-about .about-hero__title {
  margin: 16px 0 0;
  font-family: var(--font-display);
  font-size: clamp(38px, 8.2vw, 96px);
  font-weight: 800;
  line-height: 0.95;
  letter-spacing: -0.02em;
}

.page-about .about-hero__title span {
  display: block;
  font-weight: 300;
  color: var(--mist);
}

.page-about .about-hero__lede {
  max-width: 46ch;
  margin: 22px 0 0;
  color: rgba(255, 255, 255, 0.82);
  font-size: var(--step-17);
  line-height: 1.75;
  border-left: 2px solid var(--red);
  padding-left: 16px;
}

.page-about .about-hero__facts {
  display: flex;
  flex-wrap: wrap;
  gap: 12px 30px;
  margin: 30px 0 0;
  padding: 16px 0 0;
  border-top: 1px solid var(--line);
  list-style: none;
}

.page-about .about-hero__facts li {
  display: flex;
  align-items: baseline;
  gap: 8px;
  font-size: var(--step-12);
  letter-spacing: 0.12em;
  color: var(--mist);
}

.page-about .about-hero__facts .num {
  font-size: var(--step-22);
  color: var(--white);
  letter-spacing: 0;
}

.page-about .about-body {
  padding: clamp(26px, 4vw, 56px) 0 clamp(48px, 8vw, 96px);
}

.page-about .about-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(22px, 3vw, 40px);
}

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

/* 轨道：移动端为横向刻度条 */
.page-about .about-rail {
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  padding: 12px 0 4px;
}

.page-about .about-rail__title {
  margin: 0;
  font-size: var(--step-12);
  letter-spacing: 0.14em;
  color: var(--mist);
}

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

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

.page-about .about-rail__link {
  display: flex;
  align-items: baseline;
  gap: 8px;
  padding: 7px 12px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  color: var(--white);
  text-decoration: none;
  white-space: nowrap;
  transition: border-color 120ms ease, background-color 120ms ease;
}

.page-about .about-rail__link:hover,
.page-about .about-rail__link:focus-visible {
  border-color: var(--blue);
  background: var(--night-2);
}

.page-about .about-rail__year {
  font-size: var(--step-12);
  color: var(--mist);
}

.page-about .about-rail__label {
  font-size: var(--step-14);
}

.page-about .about-rail__item.is-current .about-rail__year {
  color: var(--yellow);
}

.page-about .about-rail__item.is-current .about-rail__link {
  border-color: var(--yellow);
}

/* 章节 */
.page-about .about-section {
  padding: clamp(26px, 4.4vw, 54px) 0;
  border-top: 1px solid var(--line-soft);
}

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

.page-about .about-section__num {
  display: block;
  font-size: var(--step-34);
  line-height: 1;
  color: var(--mist);
  letter-spacing: 0.02em;
}

.page-about .about-section__title {
  margin: 6px 0 18px;
  font-family: var(--font-display);
  font-size: clamp(23px, 3.4vw, 34px);
  font-weight: 800;
  line-height: 1.22;
  letter-spacing: -0.01em;
}

.page-about .about-section__text {
  max-width: 42ch;
  margin: 0 0 14px;
  color: rgba(255, 255, 255, 0.82);
  font-size: var(--step-17);
  line-height: 1.75;
}

.page-about .about-section__note {
  max-width: 46ch;
  margin: 18px 0 0;
  padding: 12px 0 0 14px;
  border-left: 1px solid var(--line);
  font-size: var(--step-14);
  line-height: 1.7;
  color: var(--mist);
}

.page-about .about-link {
  color: var(--blue);
  text-decoration: none;
  border-bottom: 1px solid rgba(44, 123, 229, 0.5);
  padding-bottom: 1px;
}

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

/* 视角切换 */
.page-about .about-tabs {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 20px 0 18px;
}

.page-about .about-tab {
  padding: 8px 14px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: transparent;
  color: var(--mist);
  font-family: var(--font-body);
  font-size: var(--step-12);
  letter-spacing: 0.08em;
  cursor: pointer;
  transition: background-color 120ms ease, color 120ms ease, border-color 120ms ease;
}

.page-about .about-tab:hover,
.page-about .about-tab:focus-visible {
  border-color: var(--blue);
  color: var(--white);
}

.page-about .about-tab[aria-pressed="true"] {
  background: var(--paper);
  border-color: var(--paper);
  color: var(--paper-ink);
}

.page-about .about-meanings {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 14px;
}

.page-about .about-meaning {
  padding: 18px 18px 20px;
  background: var(--paper);
  border: 1px solid var(--paper-line);
  border-radius: var(--radius);
  color: var(--paper-ink);
  transition: transform 120ms ease, opacity 120ms ease;
}

.page-about .about-meaning.is-hidden {
  display: none;
}

.page-about .about-meaning__tag {
  display: inline-block;
  margin: 0 0 12px;
  padding: 3px 9px;
  font-size: var(--step-12);
  letter-spacing: 0.12em;
  color: var(--white);
}

.page-about .about-meaning__tag--red {
  background: var(--red);
}

.page-about .about-meaning__tag--green {
  background: var(--green);
}

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

.page-about .about-meaning__title {
  margin: 0 0 10px;
  font-family: var(--font-display);
  font-size: var(--step-22);
  font-weight: 800;
  line-height: 1.35;
  color: var(--paper-ink);
}

.page-about .about-meaning__text {
  margin: 0 0 14px;
  font-size: var(--step-14);
  line-height: 1.8;
  color: #2A2E42;
}

.page-about .about-meaning .about-link {
  color: #1B4C99;
  border-bottom-color: rgba(27, 76, 153, 0.45);
  font-size: var(--step-14);
}

.page-about .about-meaning .about-link:hover,
.page-about .about-meaning .about-link:focus-visible {
  color: var(--red);
  border-bottom-color: var(--red);
}

/* 一场比赛的流程 */
.page-about .about-workflow {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 22px;
}

.page-about .about-steps {
  margin: 22px 0 0;
  padding: 0 0 0 18px;
  border-left: 1px solid var(--line);
  list-style: none;
}

.page-about .about-step {
  position: relative;
  padding: 0 0 20px;
}

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

.page-about .about-step::before {
  content: "";
  position: absolute;
  left: -22px;
  top: 7px;
  width: 7px;
  height: 7px;
  background: var(--yellow);
}

.page-about .about-step__head {
  margin: 0 0 6px;
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 10px;
  font-size: var(--step-17);
  font-weight: 700;
  letter-spacing: 0.01em;
}

.page-about .about-step__head .num {
  font-size: var(--step-12);
  letter-spacing: 0.08em;
  color: var(--yellow);
  border: 1px solid rgba(245, 197, 24, 0.45);
  padding: 2px 6px;
}

.page-about .about-step__text {
  margin: 0;
  max-width: 40ch;
  font-size: var(--step-14);
  line-height: 1.75;
  color: rgba(255, 255, 255, 0.74);
}

/* 图片 */
.page-about .about-figure {
  margin: 0;
}

.page-about .about-figure img,
.page-about .about-break img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  object-fit: cover;
  border: 1px solid var(--line);
}

.page-about .media__caption,
.page-about .about-break__caption {
  margin-top: 8px;
  font-size: var(--step-12);
  letter-spacing: 0.04em;
  color: var(--mist);
  line-height: 1.6;
}

.page-about .about-figure--banner {
  margin: 4px 0 20px;
}

/* 九年断点 */
.page-about .about-break {
  margin: clamp(26px, 4.5vw, 52px) 0;
  padding-top: clamp(22px, 3.4vw, 36px);
  border-top: 1px solid var(--line);
}

.page-about .about-break img {
  border-color: rgba(40, 51, 110, 0.9);
}

/* 团队规模横条 */
.page-about .about-bars {
  margin: 22px 0 0;
  display: grid;
  gap: 16px;
  max-width: 540px;
}

.page-about .about-bar__label {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 12px;
  margin: 0 0 7px;
  font-size: var(--step-14);
  color: var(--mist);
}

.page-about .about-bar__label .num {
  color: var(--white);
  font-size: var(--step-17);
  letter-spacing: 0.02em;
}

.page-about .about-bar__track {
  height: 10px;
  background: var(--night-2);
  border: 1px solid var(--line);
}

.page-about .about-bar__fill {
  display: block;
  height: 100%;
}

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

.page-about .about-bar__fill--green {
  background: var(--green);
}

.page-about .about-stats {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 12px;
  margin: 24px 0 0;
  padding: 0;
  list-style: none;
}

.page-about .about-stats li {
  display: flex;
  align-items: baseline;
  gap: 12px;
  padding: 10px 0 10px 14px;
  border-left: 1px solid var(--line);
  font-size: var(--step-14);
  color: var(--mist);
}

.page-about .about-stats .num {
  font-size: var(--step-22);
  color: var(--white);
}

/* 读者 */
.page-about .about-readers {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 12px;
  margin: 20px 0 0;
}

.page-about .about-readers__card {
  padding: 16px 16px 18px;
  background: var(--night-2);
  border: 1px solid var(--line);
  border-left: 2px solid var(--red);
}

.page-about .about-readers__card:nth-child(2) {
  border-left-color: var(--yellow);
}

.page-about .about-readers__card:nth-child(3) {
  border-left-color: var(--green);
}

.page-about .about-readers__num {
  margin: 0 0 6px;
  font-size: var(--step-34);
  line-height: 1;
  color: var(--white);
}

.page-about .about-readers__label {
  margin: 0;
  font-size: var(--step-12);
  letter-spacing: 0.1em;
  color: var(--mist);
}

/* 合作与收束 */
.page-about .about-cta {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin: 24px 0 0;
}

@media (min-width: 620px) {
  .page-about .about-meanings {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

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

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

@media (min-width: 900px) {
  .page-about .about-layout {
    grid-template-columns: var(--rail) minmax(0, 1fr);
    gap: clamp(30px, 4vw, 64px);
  }

  .page-about .about-rail {
    position: sticky;
    top: calc(var(--header-h) + 24px);
    align-self: start;
    border-top: 0;
    border-bottom: 0;
    border-left: 1px solid var(--line);
    padding: 4px 0 4px 18px;
  }

  .page-about .about-rail__list {
    display: block;
    margin-top: 14px;
    padding: 0;
    overflow: visible;
  }

  .page-about .about-rail__item {
    position: relative;
    padding: 9px 0;
  }

  .page-about .about-rail__item::before {
    content: "";
    position: absolute;
    left: -21px;
    top: 16px;
    width: 7px;
    height: 7px;
    background: var(--line);
  }

  .page-about .about-rail__item.is-current::before {
    background: var(--yellow);
  }

  .page-about .about-rail__link {
    flex-direction: column;
    align-items: flex-start;
    gap: 2px;
    padding: 0;
    border: 0;
    background: transparent;
  }

  .page-about .about-rail__link:hover,
  .page-about .about-rail__link:focus-visible {
    background: transparent;
    border: 0;
  }

  .page-about .about-rail__link:hover .about-rail__label {
    color: var(--blue);
  }

  .page-about .about-rail__year {
    font-size: var(--step-12);
    letter-spacing: 0.1em;
  }

  .page-about .about-rail__label {
    font-size: var(--step-14);
    color: var(--white);
    transition: color 120ms ease;
  }

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

  .page-about .about-workflow {
    grid-template-columns: minmax(0, 1.15fr) minmax(0, 0.85fr);
    gap: clamp(24px, 3.4vw, 44px);
    align-items: start;
  }

  .page-about .about-figure {
    position: sticky;
    top: calc(var(--header-h) + 32px);
  }
}

@media (min-width: 1200px) {
  .page-about .about-section__text {
    font-size: var(--step-17);
  }

  .page-about .about-workflow {
    grid-template-columns: minmax(0, 1.2fr) minmax(0, 0.8fr);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-tab,
  .page-about .about-meaning,
  .page-about .about-rail__link,
  .page-about .about-rail__label {
    transition: none;
  }
}
<<<END>>>