.page-about {
  --about-hair: rgba(140, 147, 166, .26);
  --about-paper-line: rgba(227, 178, 60, .3);
  color: var(--paper);
}

.page-about > section {
  padding-block: clamp(44px, 6vw, 92px);
  position: relative;
}

.page-about > section + section {
  border-top: 1px solid var(--about-hair);
}

.page-about > section:first-child {
  padding-top: clamp(22px, 3vw, 40px);
}

.page-about > section:last-child {
  padding-bottom: clamp(48px, 7vw, 104px);
}

.page-about .breadcrumb {
  display: flex;
  align-items: center;
  gap: 8px;
  flex-wrap: wrap;
  font-family: var(--font-mono);
  font-size: var(--t-12);
  letter-spacing: .04em;
  color: var(--mist);
  margin-bottom: clamp(24px, 4vw, 52px);
}

.page-about .breadcrumb a {
  color: var(--mist);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color .16s var(--ease), border-color .16s var(--ease);
}

.page-about .breadcrumb a:hover,
.page-about .breadcrumb a:focus-visible {
  color: var(--turquoise);
  border-bottom-color: var(--turquoise);
}

.page-about .breadcrumb [aria-current="page"] {
  color: var(--barley);
}

.page-about .kicker {
  font-family: var(--font-mono);
  font-size: var(--t-12);
  letter-spacing: .16em;
  color: var(--crimson);
  margin: 0 0 14px;
}

.page-about .section__head {
  display: flex;
  align-items: baseline;
  gap: 14px;
  flex-wrap: wrap;
  margin-bottom: clamp(24px, 3.6vw, 46px);
}

.page-about .section__index {
  font-family: var(--font-mono);
  font-size: var(--t-13);
  letter-spacing: .12em;
  color: var(--crimson);
}

.page-about .section__title {
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(24px, 3.4vw, 44px);
  line-height: 1.24;
  letter-spacing: -.01em;
  color: var(--paper);
  margin: 0;
  max-width: 24ch;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  background-image:
    radial-gradient(120% 90% at 90% 0%, rgba(23, 163, 152, .13), transparent 62%),
    radial-gradient(80% 70% at 4% 100%, rgba(217, 58, 43, .13), transparent 60%);
}

.page-about .about-hero__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(24px, 3.4vw, 44px);
  align-items: start;
}

.page-about .about-hero__lead h1 {
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(32px, 6.4vw, 72px);
  line-height: 1.1;
  letter-spacing: -.02em;
  color: var(--paper);
  margin: 0 0 clamp(18px, 2.4vw, 26px);
}

.page-about .about-hero__intro {
  font-size: var(--t-18);
  line-height: 1.85;
  color: var(--mist);
  margin: 0;
  max-width: 46ch;
}

.page-about .about-hero__meta {
  margin: clamp(20px, 2.6vw, 30px) 0 0;
  font-family: var(--font-mono);
  font-size: var(--t-13);
  letter-spacing: .04em;
  color: var(--barley);
}

.page-about .about-hero__aside {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 16px;
  padding-left: clamp(14px, 2vw, 22px);
  border-left: 1px solid var(--about-paper-line);
}

.page-about .about-hero__aside .vertical-note {
  color: var(--gold);
  letter-spacing: .26em;
  margin: 0;
}

.page-about .about-hero__stages {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 16px;
}

.page-about .about-hero__stages li {
  display: grid;
  grid-template-columns: 26px minmax(0, 1fr);
  column-gap: 8px;
  row-gap: 4px;
  padding-bottom: 14px;
  border-bottom: 1px solid var(--about-hair);
}

.page-about .about-hero__stages li:last-child {
  border-bottom: 0;
  padding-bottom: 0;
}

.page-about .about-hero__num {
  font-family: var(--font-mono);
  font-size: var(--t-13);
  color: var(--crimson);
  line-height: 1.6;
}

.page-about .about-hero__stages strong {
  font-family: var(--font-display);
  font-size: var(--t-18);
  color: var(--paper);
  font-weight: 700;
  line-height: 1.5;
}

.page-about .about-hero__desc {
  grid-column: 2;
  font-size: var(--t-13);
  line-height: 1.75;
  color: var(--mist);
}

.page-about .about-hero__figure {
  margin: clamp(28px, 4vw, 52px) 0 0;
}

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

.page-about .about-hero__figure::before {
  content: "";
  display: block;
  height: 6px;
  background: linear-gradient(90deg,
    var(--crimson) 0 20%,
    var(--gold) 20% 40%,
    var(--turquoise) 40% 60%,
    var(--barley) 60% 80%,
    var(--clay) 80% 100%);
}

.page-about figcaption {
  margin-top: 12px;
  font-family: var(--font-mono);
  font-size: var(--t-12);
  line-height: 1.8;
  color: var(--rock);
}

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

.page-about .about-origin__head .section__title {
  max-width: 20ch;
}

.page-about .about-origin__body .prose {
  font-size: var(--t-18);
  line-height: 2;
  color: var(--mist);
  margin: 0 0 1.5em;
}

.page-about .about-origin__rules {
  list-style: none;
  counter-reset: originrule;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 14px;
}

.page-about .about-origin__rules li {
  counter-increment: originrule;
  position: relative;
  padding-left: 46px;
  font-size: var(--t-16);
  line-height: 1.85;
  color: var(--paper);
}

.page-about .about-origin__rules li::before {
  content: "0" counter(originrule);
  position: absolute;
  left: 0;
  top: 2px;
  font-family: var(--font-mono);
  font-size: var(--t-13);
  color: var(--crimson);
  letter-spacing: .06em;
}

.page-about .about-origin__tail {
  margin: clamp(22px, 3vw, 32px) 0 0;
  font-size: var(--t-16);
  line-height: 1.85;
  color: var(--mist);
}

.page-about a {
  color: var(--turquoise);
  text-decoration: none;
  border-bottom: 1px solid rgba(23, 163, 152, .5);
  transition: color .16s var(--ease), border-color .16s var(--ease);
}

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

/* ---------- 时间轴 ---------- */
.page-about .about-phases__track {
  list-style: none;
  margin: 0;
  padding: 0 0 0 22px;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 18px;
  position: relative;
}

.page-about .about-phases__track::before {
  content: "";
  position: absolute;
  left: 7px;
  top: 0;
  bottom: 0;
  width: 1px;
  background: linear-gradient(180deg, var(--gold), rgba(227, 178, 60, .12));
}

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

.page-about .about-phase::before {
  content: "";
  position: absolute;
  left: -15px;
  top: 30px;
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--crimson);
  border: 2px solid var(--gold);
  transform: translateX(-50%);
  z-index: 1;
}

.page-about .about-phase__card {
  background: var(--ink);
  border: 1px solid var(--about-hair);
  padding: clamp(18px, 2.2vw, 24px);
  transition: transform .16s var(--ease), border-color .16s var(--ease), box-shadow .16s var(--ease);
  position: relative;
}

.page-about .about-phase__card::after {
  content: "";
  position: absolute;
  inset: 6px -6px -6px 6px;
  border: 1px solid rgba(180, 89, 59, .34);
  z-index: -1;
  pointer-events: none;
}

.page-about .about-phase__card:hover {
  transform: translateY(-4px);
  border-color: var(--gold);
  box-shadow: 0 10px 26px rgba(10, 18, 40, .5);
}

.page-about .about-phase__card .tag {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: var(--t-12);
  letter-spacing: .08em;
  padding: 4px 9px;
  margin-bottom: 14px;
  border: 1px solid currentColor;
  color: var(--crimson);
}

.page-about .about-phase__card .tag--turquoise { color: var(--turquoise); }
.page-about .about-phase__card .tag--gold { color: var(--gold); }

.page-about .about-phase__title {
  font-family: var(--font-display);
  font-size: var(--t-20);
  line-height: 1.42;
  font-weight: 700;
  color: var(--paper);
  margin: 0 0 12px;
}

.page-about .about-phase__text {
  font-size: var(--t-16);
  line-height: 1.85;
  color: var(--mist);
  margin: 0;
}

.page-about .about-phase__meta {
  margin: 16px 0 0;
  padding-top: 12px;
  border-top: 1px dashed var(--about-hair);
  font-family: var(--font-mono);
  font-size: var(--t-12);
  letter-spacing: .04em;
  color: var(--rock);
}

.page-about .about-phases__figure {
  margin: clamp(30px, 4vw, 52px) 0 0;
}

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

/* ---------- 数字档案 ---------- */
.page-about .about-figures__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  margin: 0;
  background: var(--about-hair);
  border: 1px solid var(--about-hair);
}

.page-about .about-figure {
  background: var(--ink);
  padding: 22px 18px 24px;
  display: grid;
  grid-template-areas: "value" "label" "note";
  align-content: start;
  gap: 8px;
  transition: background .16s var(--ease);
}

.page-about .about-figure:hover {
  background: #223363;
}

.page-about .about-figure__value {
  grid-area: value;
  margin: 0;
  display: flex;
  align-items: baseline;
  gap: 4px;
}

.page-about .about-figure__num {
  font-family: var(--font-mono);
  font-size: clamp(38px, 5vw, 72px);
  line-height: 1;
  letter-spacing: -.03em;
  color: var(--barley);
}

.page-about .about-figure__unit {
  font-family: var(--font-display);
  font-size: var(--t-18);
  color: var(--gold);
}

.page-about .about-figure__label {
  grid-area: label;
  font-family: var(--font-mono);
  font-size: var(--t-12);
  letter-spacing: .1em;
  color: var(--mist);
}

.page-about .about-figure__note {
  grid-area: note;
  margin: 0;
  font-size: var(--t-13);
  line-height: 1.75;
  color: var(--mist);
}

/* ---------- 团队 ---------- */
.page-about .about-team__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(26px, 3.6vw, 48px);
  align-items: start;
}

.page-about .about-team__copy .section__title {
  max-width: 18ch;
}

.page-about .about-team__lead {
  font-size: var(--t-18);
  line-height: 1.9;
  color: var(--mist);
  margin: 0 0 clamp(20px, 2.8vw, 30px);
  max-width: 40ch;
}

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

.page-about .about-team__cell {
  background: var(--ink-deep);
  padding: 18px;
  border-top: 3px solid var(--rock);
}

.page-about .about-team__cell--crimson { border-top-color: var(--crimson); }
.page-about .about-team__cell--turquoise { border-top-color: var(--turquoise); }
.page-about .about-team__cell--gold { border-top-color: var(--gold); }
.page-about .about-team__cell--clay { border-top-color: var(--clay); }

.page-about .about-team__cell h3 {
  font-family: var(--font-display);
  font-size: var(--t-18);
  font-weight: 700;
  color: var(--paper);
  margin: 0 0 8px;
}

.page-about .about-team__cell p {
  margin: 0;
  font-size: var(--t-16);
  line-height: 1.8;
  color: var(--mist);
}

.page-about .about-team__tail {
  margin: clamp(20px, 2.6vw, 28px) 0 0;
  font-size: var(--t-16);
  line-height: 1.9;
  color: var(--mist);
  padding-left: 16px;
  border-left: 2px solid var(--clay);
}

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

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

/* ---------- 更新节奏 ---------- */
.page-about .about-cadence__intro {
  font-size: var(--t-18);
  line-height: 2;
  color: var(--mist);
  margin: 0 0 clamp(24px, 3.4vw, 40px);
}

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

.page-about .about-cadence__item {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 8px;
  padding: 20px 0;
  background: var(--ink-deep);
}

.page-about .about-cadence__when {
  font-family: var(--font-mono);
  font-size: var(--t-13);
  letter-spacing: .08em;
  color: var(--gold);
}

.page-about .about-cadence__body h3 {
  font-family: var(--font-display);
  font-size: var(--t-20);
  font-weight: 700;
  color: var(--paper);
  margin: 0 0 8px;
}

.page-about .about-cadence__body p {
  margin: 0;
  font-size: var(--t-16);
  line-height: 1.9;
  color: var(--mist);
}

/* ---------- 自我要求 ---------- */
.page-about .about-standard__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(22px, 3vw, 40px);
}

.page-about .about-standard__intro {
  font-size: var(--t-16);
  line-height: 1.9;
  color: var(--mist);
  margin: 16px 0 0;
  max-width: 30ch;
}

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

.page-about .about-standard__card {
  background: var(--paper);
  color: var(--ink-deep);
  padding: 20px 20px 22px;
  border-left: 5px solid var(--crimson);
}

.page-about .about-standard__card:nth-child(2) { border-left-color: var(--turquoise); }
.page-about .about-standard__card:nth-child(3) { border-left-color: var(--clay); }

.page-about .about-standard__card h3 {
  font-family: var(--font-display);
  font-size: var(--t-18);
  font-weight: 700;
  color: var(--ink-deep);
  margin: 0 0 10px;
}

.page-about .about-standard__card p {
  margin: 0;
  font-size: var(--t-16);
  line-height: 1.85;
  color: #2b3a63;
}

/* ---------- 下一步 ---------- */
.page-about .about-next__title {
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(22px, 3vw, 36px);
  line-height: 1.3;
  color: var(--paper);
  margin: 0 0 clamp(22px, 3vw, 36px);
}

.page-about .about-next__links {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  background: var(--about-hair);
  border: 1px solid var(--about-hair);
}

.page-about .about-next__link {
  display: block;
  background: var(--ink);
  padding: 18px 20px;
  text-decoration: none;
  border-bottom: 0;
  transition: background .16s var(--ease), padding-left .16s var(--ease);
}

.page-about .about-next__link:hover,
.page-about .about-next__link:focus-visible {
  background: #223363;
  padding-left: 26px;
}

.page-about .about-next__label {
  display: block;
  font-family: var(--font-display);
  font-size: var(--t-20);
  font-weight: 700;
  color: var(--barley);
  margin-bottom: 6px;
}

.page-about .about-next__desc {
  display: block;
  font-size: var(--t-13);
  line-height: 1.75;
  color: var(--mist);
}

/* ---------- 断点 ---------- */
@media (min-width: 720px) {
  .page-about .about-figures__grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .page-about .about-standard__cards {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 1px;
    background: var(--about-hair);
    border: 1px solid var(--about-hair);
  }

  .page-about .about-standard__card {
    border-left: 0;
    border-top: 5px solid var(--crimson);
    padding: 20px 18px 22px;
  }

  .page-about .about-standard__card:nth-child(2) { border-top-color: var(--turquoise); }
  .page-about .about-standard__card:nth-child(3) { border-top-color: var(--clay); }

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

  .page-about .about-cadence__item {
    grid-template-columns: 190px minmax(0, 1fr);
    align-items: start;
    gap: 20px;
    padding: 22px 4px;
  }

  .page-about .about-cadence__when {
    padding-top: 4px;
  }

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

  .page-about .about-hero__figure {
    margin-top: clamp(32px, 4vw, 56px);
  }
}

@media (min-width: 900px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 4fr);
    gap: clamp(28px, 4vw, 56px);
  }

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

  .page-about .about-origin__grid {
    grid-template-columns: minmax(0, 4fr) minmax(0, 7fr);
    gap: clamp(28px, 4vw, 56px);
  }

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

  .page-about .about-team__grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 4fr);
    gap: clamp(28px, 4vw, 52px);
  }

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

  .page-about .about-standard__grid {
    grid-template-columns: minmax(0, 4fr) minmax(0, 7fr);
    gap: clamp(28px, 4vw, 56px);
    align-items: start;
  }

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

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

  /* 时间轴：三列、上下交错、横轴贯穿 */
  .page-about .about-phases__track {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    grid-template-rows: auto auto;
    column-gap: clamp(16px, 2.2vw, 28px);
    row-gap: 0;
    padding-left: 0;
  }

  .page-about .about-phases__track::before {
    left: 0;
    right: 0;
    top: 50%;
    bottom: auto;
    width: auto;
    height: 1px;
    background: linear-gradient(90deg, transparent, var(--gold) 9%, var(--gold) 91%, transparent);
    opacity: .45;
  }

  .page-about .about-phase:nth-child(1),
  .page-about .about-phase:nth-child(3) {
    grid-row: 1;
    align-self: end;
    margin-bottom: 30px;
  }

  .page-about .about-phase:nth-child(2) {
    grid-row: 2;
    align-self: start;
    margin-top: 30px;
  }

  .page-about .about-phase::before {
    left: 50%;
    transform: translateX(-50%);
  }

  .page-about .about-phase:nth-child(1)::before,
  .page-about .about-phase:nth-child(3)::before {
    top: auto;
    bottom: -36px;
  }

  .page-about .about-phase:nth-child(2)::before {
    top: -36px;
    bottom: auto;
  }

  .page-about .about-phases__figure {
    margin-top: clamp(34px, 4.4vw, 60px);
    width: 86%;
    margin-left: auto;
  }
}

@media (min-width: 1180px) {
  .page-about .about-phases__figure {
    width: 72%;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-phase__card,
  .page-about .about-figure,
  .page-about .about-next__link,
  .page-about a {
    transition: none;
  }

  .page-about .about-phase__card:hover {
    transform: none;
  }
}
<<<END>>>