.page-about {
  display: block;
  background: var(--c-cool);
  color: var(--c-navy);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  background: var(--c-navy);
  color: var(--c-cool);
  padding-top: calc(var(--h-bar) + clamp(28px, 5vw, 64px));
  overflow: hidden;
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  right: -80px;
  top: -120px;
  width: 420px;
  height: 420px;
  background: radial-gradient(circle, rgba(228, 0, 43, .38) 0%, rgba(228, 0, 43, 0) 68%);
  pointer-events: none;
}

.page-about .about-hero__inner {
  position: relative;
  z-index: 1;
  padding-bottom: clamp(36px, 6vw, 72px);
}

.page-about .about-hero .tb-crumbs {
  color: var(--c-steel);
}

.page-about .about-hero .tb-kicker {
  color: var(--c-cyan);
}

.page-about .about-hero__grid {
  display: grid;
  gap: clamp(28px, 5vw, 56px);
  margin-top: clamp(24px, 4vw, 44px);
}

.page-about .about-hero__title {
  font-family: var(--f-display);
  font-size: clamp(32px, 6.2vw, 64px);
  line-height: 1.06;
  letter-spacing: -0.02em;
  font-weight: 900;
  color: var(--c-white);
  margin: 14px 0 20px;
}

.page-about .about-hero__lead {
  max-width: 620px;
  color: rgba(244, 246, 249, .84);
  font-size: var(--fs-sm);
  line-height: 1.9;
}

.page-about .about-hero__band {
  height: 14px;
  background: var(--checker);
  background-size: var(--checker-size);
}

.page-about .about-board {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 2px;
  background: rgba(168, 180, 196, .38);
  border: 2px solid rgba(168, 180, 196, .38);
}

.page-about .about-board__cell {
  background: var(--c-navy-2);
  padding: 18px 16px 16px;
  display: flex;
  flex-direction: column;
  gap: 8px;
  min-width: 0;
}

.page-about .about-board__label {
  font-size: var(--fs-xs);
  line-height: 1.55;
  color: var(--c-steel);
  letter-spacing: .02em;
}

.page-about .about-num {
  display: block;
  font-family: var(--f-mono);
  font-size: clamp(28px, 3.4vw, 40px);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--c-red);
  font-variant-numeric: tabular-nums;
}

.page-about .about-num--light {
  color: var(--c-red-lift);
}

/* ---------- 正文布局 ---------- */
.page-about .about-layout {
  padding-top: clamp(36px, 6vw, 76px);
  padding-bottom: clamp(48px, 8vw, 96px);
}

.page-about .about-index {
  margin-bottom: 32px;
}

.page-about .about-index__title {
  font-family: var(--f-mono);
  font-size: 11px;
  letter-spacing: .28em;
  color: var(--c-steel);
  margin: 0 0 12px;
}

.page-about .about-index__list {
  list-style: none;
  margin: 0;
  padding: 0 0 6px;
  display: flex;
  gap: 8px;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
}

.page-about .about-index__list > li {
  flex: 0 0 auto;
}

.page-about .about-index__link {
  display: flex;
  align-items: baseline;
  gap: 8px;
  white-space: nowrap;
  padding: 9px 14px;
  border: 2px solid var(--c-line);
  background: var(--c-white);
  color: var(--c-navy);
  text-decoration: none;
  font-size: var(--fs-xs);
  transition: border-color var(--dur) var(--ease), color var(--dur) var(--ease), background var(--dur) var(--ease);
}

.page-about .about-index__num {
  font-family: var(--f-mono);
  font-size: 11px;
  letter-spacing: .08em;
  color: var(--c-steel);
}

.page-about .about-index__link:hover,
.page-about .about-index__link:focus-visible,
.page-about .about-index__link.is-active,
.page-about .about-index__link[aria-current="true"] {
  border-color: var(--c-red);
  color: var(--c-red);
}

.page-about .about-index__link:hover .about-index__num,
.page-about .about-index__link.is-active .about-index__num {
  color: var(--c-red);
}

/* ---------- 章节 ---------- */
.page-about .about-section {
  padding-bottom: clamp(40px, 6vw, 72px);
  margin-bottom: clamp(40px, 6vw, 72px);
  border-bottom: 1px solid rgba(168, 180, 196, .55);
  scroll-margin-top: calc(var(--h-bar) + 24px);
}

.page-about .about-section:last-child {
  border-bottom: 0;
  margin-bottom: 0;
  padding-bottom: 0;
}

.page-about .about-section .tb-h2 {
  margin: 10px 0 20px;
}

.page-about .about-prose-gap {
  margin-top: 26px;
}

.page-about .about-next {
  margin: 26px 0 0;
  padding-left: 16px;
  border-left: 3px solid var(--c-cyan);
  font-size: var(--fs-xs);
  line-height: 1.85;
  color: var(--c-steel);
}

.page-about .about-next a {
  color: var(--c-red);
  text-decoration: none;
  border-bottom: 1px solid currentColor;
}

.page-about .about-next a:hover {
  color: var(--c-red-deep);
}

.page-about .about-mail {
  font-family: var(--f-mono);
  color: var(--c-navy);
  word-break: break-all;
}

/* ---------- 主张块 ---------- */
.page-about .about-motto {
  margin-top: 30px;
  background: var(--c-white);
  border: 2px solid var(--c-navy);
  border-left: 8px solid var(--c-red);
  box-shadow: var(--hard);
  padding: 22px 22px 22px 20px;
}

.page-about .about-motto__line {
  font-family: var(--f-display);
  font-size: clamp(24px, 3.2vw, 34px);
  font-weight: 900;
  letter-spacing: -0.02em;
  line-height: 1.1;
  margin: 0 0 12px;
  color: var(--c-navy);
}

.page-about .about-motto__text {
  margin: 0;
  font-size: var(--fs-sm);
  line-height: 1.85;
  color: var(--c-navy);
}

/* ---------- 图片 ---------- */
.page-about .about-shot {
  margin: 28px 0 0;
}

.page-about .about-shot--side {
  margin-top: 20px;
}

.page-about .about-figure {
  position: relative;
  overflow: hidden;
  border: 2px solid var(--c-navy);
  background: var(--c-navy-2);
  box-shadow: var(--hard);
}

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

.page-about .about-figure--14x9 {
  aspect-ratio: 14 / 9;
}

.page-about .about-figure--4x3 {
  aspect-ratio: 4 / 3;
}

.page-about .about-figure--8x3 {
  aspect-ratio: 8 / 3;
}

.page-about .about-figure--texture {
  margin-top: 26px;
  box-shadow: none;
  border-color: var(--c-navy);
}

.page-about .about-figure__tag {
  position: absolute;
  left: 0;
  bottom: 0;
  padding: 6px 12px;
  background: var(--c-red);
  color: var(--c-white);
  font-family: var(--f-mono);
  font-size: 12px;
  letter-spacing: .1em;
}

.page-about .about-shot__caption {
  margin: 12px 0 0;
  font-size: var(--fs-xs);
  line-height: 1.7;
  color: var(--c-steel);
}

/* ---------- 团队比例条 ---------- */
.page-about .about-roles {
  list-style: none;
  margin: 28px 0 0;
  padding: 0;
  display: grid;
  gap: 2px;
  background: rgba(168, 180, 196, .55);
  border: 2px solid var(--c-navy);
}

.page-about .about-roles__row {
  background: var(--c-white);
  padding: 18px 18px 16px;
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  align-items: baseline;
  gap: 8px 16px;
}

.page-about .about-roles__name {
  font-family: var(--f-display);
  font-size: var(--fs-md);
  font-weight: 700;
  letter-spacing: -0.01em;
  color: var(--c-navy);
}

.page-about .about-roles__num {
  font-family: var(--f-mono);
  font-size: var(--fs-md);
  font-weight: 700;
  color: var(--c-red);
  font-variant-numeric: tabular-nums;
}

.page-about .about-roles__desc {
  grid-column: 1 / -1;
  margin: 0;
  font-size: var(--fs-xs);
  line-height: 1.75;
  color: var(--c-steel);
}

.page-about .about-roles__bar {
  grid-column: 1 / -1;
  display: block;
  height: 10px;
  background: var(--c-cool);
  border: 1px solid var(--c-line);
}

.page-about .about-roles__bar i {
  display: block;
  height: 100%;
  background: var(--c-navy);
  transition: background var(--dur) var(--ease);
}

.page-about .about-roles__row:nth-child(1) .about-roles__bar i { width: 32.5%; }
.page-about .about-roles__row:nth-child(2) .about-roles__bar i { width: 17.5%; }
.page-about .about-roles__row:nth-child(3) .about-roles__bar i { width: 38.8%; }
.page-about .about-roles__row:nth-child(4) .about-roles__bar i { width: 11.2%; }

.page-about .about-roles__row:hover .about-roles__bar i,
.page-about .about-roles__row:focus-within .about-roles__bar i {
  background: var(--c-red);
}

/* ---------- 生产流程 ---------- */
.page-about .about-pipeline {
  margin-top: 28px;
}

.page-about .about-steps {
  display: grid;
  gap: 10px;
}

.page-about .about-step {
  border: 2px solid var(--c-navy);
  background: var(--c-white);
}

.page-about .about-step__sum {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 16px 18px;
  cursor: pointer;
  list-style: none;
  transition: background var(--dur) var(--ease);
}

.page-about .about-step__sum::-webkit-details-marker {
  display: none;
}

.page-about .about-step__sum::after {
  content: "+";
  margin-left: auto;
  font-family: var(--f-mono);
  font-size: 22px;
  line-height: 1;
  color: var(--c-red);
}

.page-about .about-step[open] .about-step__sum {
  background: var(--c-cool);
}

.page-about .about-step[open] .about-step__sum::after {
  content: "\2212";
}

.page-about .about-step__code {
  flex: 0 0 auto;
  font-family: var(--f-mono);
  font-size: 12px;
  letter-spacing: .06em;
  padding: 5px 10px;
  background: var(--c-navy);
  color: var(--c-white);
  white-space: nowrap;
}

.page-about .about-step:last-child .about-step__code {
  background: var(--c-red);
}

.page-about .about-step__name {
  font-family: var(--f-display);
  font-size: var(--fs-sm);
  font-weight: 700;
  letter-spacing: -.01em;
  color: var(--c-navy);
}

.page-about .about-step__body {
  padding: 0 18px 18px;
  border-top: 1px solid rgba(168, 180, 196, .55);
  margin-top: 0;
}

.page-about .about-step__body p {
  margin: 14px 0 0;
  font-size: var(--fs-sm);
  line-height: 1.85;
  color: var(--c-navy);
}

/* ---------- 时间轴 ---------- */
.page-about .about-timeline {
  list-style: none;
  margin: 30px 0 0;
  padding: 0;
}

.page-about .about-timeline__item {
  position: relative;
  padding: 24px 0 24px 24px;
  border-left: 2px solid var(--c-line);
}

.page-about .about-timeline__item::before {
  content: "";
  position: absolute;
  left: -7px;
  top: 32px;
  width: 12px;
  height: 12px;
  background: var(--c-red);
  clip-path: polygon(50% 0, 100% 50%, 50% 100%, 0 50%);
}

.page-about .about-timeline__item:last-child {
  border-left-color: transparent;
}

.page-about .about-timeline__year {
  display: block;
  font-family: var(--f-mono);
  font-size: 26px;
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--c-navy);
  font-variant-numeric: tabular-nums;
}

.page-about .about-timeline__body {
  margin-top: 10px;
}

.page-about .about-timeline__body .tb-h4 {
  margin: 0 0 8px;
}

.page-about .about-timeline__body p {
  margin: 0;
  font-size: var(--fs-sm);
  line-height: 1.85;
  color: var(--c-navy);
}

/* ---------- 数据来源 ---------- */
.page-about .about-partners {
  display: grid;
  gap: 2px;
  margin-top: 28px;
  background: rgba(168, 180, 196, .5);
  border: 2px solid var(--c-navy);
}

.page-about .about-partners__cell {
  background: var(--c-navy);
  color: var(--c-cool);
  padding: 24px 20px;
}

.page-about .about-partners__cell p {
  margin: 12px 0 0;
  font-size: var(--fs-xs);
  line-height: 1.8;
  color: rgba(244, 246, 249, .78);
}

/* ---------- 成果 ---------- */
.page-about .about-results {
  display: grid;
  gap: 2px;
  margin-top: 28px;
  background: rgba(168, 180, 196, .5);
  border: 2px solid var(--c-navy);
}

.page-about .about-results__cell {
  background: var(--c-white);
  padding: 22px 18px;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.page-about .about-results__label {
  font-size: var(--fs-xs);
  line-height: 1.6;
  color: var(--c-steel);
}

/* ---------- 参与 ---------- */
.page-about .about-section--join {
  border-bottom: 0;
}

.page-about .about-join {
  display: grid;
  gap: 24px;
  margin-top: 24px;
  padding: clamp(22px, 3.4vw, 36px);
  background: var(--c-white);
  border: 2px solid var(--c-navy);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 22px), calc(100% - 96px) 100%, 0 100%);
}

.page-about .about-join__main p {
  margin: 0;
  font-size: var(--fs-sm);
  line-height: 1.85;
  color: var(--c-navy);
}

.page-about .about-join__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 22px;
}

.page-about .about-join__meta {
  border-top: 1px solid rgba(168, 180, 196, .6);
  padding-top: 18px;
}

.page-about .about-join__mlabel {
  font-family: var(--f-mono);
  font-size: 11px;
  letter-spacing: .18em;
  color: var(--c-steel);
  margin: 0 0 4px;
}

.page-about .about-join__mail {
  font-family: var(--f-mono);
  font-size: var(--fs-sm);
  color: var(--c-navy);
  word-break: break-all;
  margin: 0 0 16px;
}

.page-about .about-join__mtext {
  margin: 0;
  font-size: var(--fs-sm);
  color: var(--c-navy);
}

/* ---------- 响应式 ---------- */
@media (min-width: 640px) {
  .page-about .about-results {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

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

@media (min-width: 720px) {
  .page-about .about-timeline__item {
    display: grid;
    grid-template-columns: 116px minmax(0, 1fr);
    gap: 28px;
    align-items: start;
    padding: 26px 0 26px 26px;
  }

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

@media (min-width: 900px) {
  .page-about .about-hero__grid {
    grid-template-columns: 7fr 5fr;
    align-items: end;
    gap: clamp(32px, 5vw, 72px);
  }

  .page-about .about-join {
    grid-template-columns: minmax(0, 1.5fr) minmax(0, 1fr);
    gap: clamp(24px, 4vw, 48px);
    align-items: start;
  }

  .page-about .about-join__meta {
    border-top: 0;
    border-left: 1px solid rgba(168, 180, 196, .6);
    padding-top: 0;
    padding-left: 24px;
  }
}

@media (min-width: 1024px) {
  .page-about .about-layout {
    display: grid;
    grid-template-columns: 208px minmax(0, 1fr);
    gap: clamp(32px, 4.5vw, 76px);
    align-items: start;
  }

  .page-about .about-index {
    position: sticky;
    top: calc(var(--h-bar) + 28px);
    margin-bottom: 0;
  }

  .page-about .about-index__list {
    flex-direction: column;
    gap: 2px;
    overflow: visible;
    padding-bottom: 0;
  }

  .page-about .about-index__list > li {
    flex: 1 1 auto;
    width: 100%;
  }

  .page-about .about-index__link {
    width: 100%;
    border: 0;
    border-left: 3px solid var(--c-line);
    background: transparent;
    padding: 10px 14px;
  }

  .page-about .about-index__link:hover,
  .page-about .about-index__link:focus-visible,
  .page-about .about-index__link.is-active,
  .page-about .about-index__link[aria-current="true"] {
    border-left-color: var(--c-red);
    background: var(--c-white);
  }

  .page-about .about-pipeline {
    display: grid;
    grid-template-columns: minmax(0, 1.3fr) minmax(0, 1fr);
    gap: clamp(24px, 3.6vw, 48px);
    align-items: start;
  }

  .page-about .about-shot--side {
    margin-top: 0;
  }

  .page-about .about-results {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .about-hero__title {
    max-width: 16em;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-index__link,
  .page-about .about-roles__bar i,
  .page-about .about-step__sum {
    transition: none;
  }
}
<<<END>>>