.page-about {
  --about-rail: 48px;
  --about-line: rgba(36, 27, 22, 0.12);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  isolation: isolate;
  overflow: hidden;
  padding: calc(var(--bsm-header-h) + clamp(28px, 6vw, 64px)) 0 clamp(40px, 7vw, 76px);
  background:
    radial-gradient(120% 90% at 82% 0%, rgba(53, 240, 192, 0.14), transparent 62%),
    radial-gradient(90% 70% at 0% 100%, rgba(255, 90, 54, 0.13), transparent 66%),
    var(--bsm-night);
  color: var(--bsm-paper);
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  background-image:
    repeating-linear-gradient(90deg, rgba(46, 74, 107, 0.55) 0 1px, transparent 1px 76px),
    repeating-linear-gradient(0deg, rgba(46, 74, 107, 0.35) 0 1px, transparent 1px 76px);
  opacity: 0.42;
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  right: -18%;
  bottom: -34%;
  width: 68%;
  height: 90%;
  z-index: -1;
  pointer-events: none;
  background: linear-gradient(140deg, rgba(255, 90, 54, 0.18), transparent 62%);
  transform: rotate(9deg);
}

.page-about .about-hero__inner {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(18px, 4vw, 32px);
}

.page-about .about-crumb .bsm-breadcrumb__list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  margin: 0;
  padding: 0;
  list-style: none;
  font-size: 13px;
  letter-spacing: 0.04em;
}

.page-about .about-crumb .bsm-breadcrumb__link {
  color: var(--bsm-teal);
  text-decoration: none;
  border-bottom: 1px solid rgba(53, 240, 192, 0.4);
}

.page-about .about-crumb .bsm-breadcrumb__link:hover,
.page-about .about-crumb .bsm-breadcrumb__link:focus-visible {
  border-bottom-color: var(--bsm-teal);
}

.page-about .about-crumb .bsm-breadcrumb__sep {
  color: rgba(251, 247, 239, 0.35);
}

.page-about .about-crumb .bsm-breadcrumb__current {
  color: rgba(251, 247, 239, 0.78);
}

.page-about .about-hero .bsm-eyebrow {
  color: var(--bsm-teal);
}

.page-about .about-hero__title {
  margin: 14px 0 0;
  font-family: var(--bsm-font-serif);
  font-weight: 700;
  font-size: clamp(30px, 6vw, 52px);
  line-height: 1.18;
  letter-spacing: 0.01em;
  color: var(--bsm-paper);
}

.page-about .about-hero__lead {
  margin: 18px 0 0;
  max-width: 46em;
  font-family: var(--bsm-font-sans);
  font-size: clamp(15px, 1.7vw, 17px);
  line-height: 1.85;
  color: rgba(251, 247, 239, 0.88);
}

.page-about .about-hero__note {
  margin: 14px 0 0;
  font-family: var(--bsm-font-sans);
  font-size: 14px;
  line-height: 1.7;
  color: var(--bsm-steel);
}

.page-about .about-hero__figure {
  margin: 0;
  position: relative;
  clip-path: polygon(0 0, 100% 0, 100% 88%, 88% 100%, 0 100%);
  background: var(--bsm-night-2);
}

.page-about .about-hero__figure img {
  display: block;
  width: 100%;
  height: 100%;
  aspect-ratio: 16 / 9;
  object-fit: cover;
}

.page-about .about-hero__metrics {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: 0;
  padding: 18px 0 0;
  list-style: none;
  border-top: 1px solid rgba(46, 74, 107, 0.9);
}

.page-about .about-hero__metric {
  padding: 6px 12px 6px 0;
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.page-about .about-hero__num {
  font-family: var(--bsm-font-num);
  font-size: clamp(30px, 5vw, 42px);
  line-height: 1;
  letter-spacing: 0.02em;
  color: var(--bsm-teal);
}

.page-about .about-hero__plus {
  color: var(--bsm-flame);
  margin-left: 2px;
}

.page-about .about-hero__unit {
  font-family: var(--bsm-font-sans);
  font-size: 13px;
  letter-spacing: 0.08em;
  color: var(--bsm-steel);
}

/* ---------- 通用小节标题 ---------- */
.page-about .about-head {
  max-width: 52em;
}

.page-about .about-head__title {
  margin: 12px 0 0;
  font-family: var(--bsm-font-serif);
  font-size: clamp(24px, 4vw, 36px);
  line-height: 1.25;
  color: var(--bsm-ink);
}

.page-about .about-head__lead {
  margin: 14px 0 0;
  font-family: var(--bsm-font-sans);
  font-size: clamp(15px, 1.7vw, 17px);
  line-height: 1.85;
  color: #4a3f38;
}

.page-about .about-head--night .about-head__title {
  color: var(--bsm-paper);
}

.page-about .about-head--night .about-head__lead {
  color: rgba(251, 247, 239, 0.82);
}

.page-about .about-head--night .bsm-eyebrow {
  color: var(--bsm-teal);
}

/* ---------- 时间轴 ---------- */
.page-about .about-journey {
  background: var(--bsm-cream);
}

.page-about .about-timeline {
  position: relative;
  margin: clamp(26px, 5vw, 46px) 0 0;
  padding: 0;
  list-style: none;
}

.page-about .about-timeline::before {
  content: "";
  position: absolute;
  top: 10px;
  bottom: 10px;
  left: 13px;
  width: 2px;
  background: linear-gradient(180deg, var(--bsm-teal), rgba(53, 240, 192, 0.22) 58%, rgba(255, 90, 54, 0.85));
}

.page-about .about-stage {
  position: relative;
  margin-bottom: 16px;
  padding-left: 44px;
}

.page-about .about-stage::before {
  content: "";
  position: absolute;
  left: 7px;
  top: 26px;
  width: 12px;
  height: 12px;
  background: var(--bsm-cream);
  border: 2px solid var(--bsm-teal);
  transform: rotate(45deg);
}

.page-about .about-stage--current::before {
  background: var(--bsm-flame);
  border-color: var(--bsm-flame);
}

.page-about .about-stage__box {
  background: var(--bsm-paper);
  border-left: 3px solid var(--bsm-teal);
  clip-path: var(--bsm-cut);
  transition: background 0.2s ease;
}

.page-about .about-stage--current .about-stage__box {
  border-left-color: var(--bsm-flame);
}

.page-about .about-stage__box[open] {
  background: #fffdf8;
}

.page-about .about-stage__summary {
  position: relative;
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 6px 14px;
  padding: 18px 46px 18px 20px;
  cursor: pointer;
  list-style: none;
}

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

.page-about .about-stage__summary::after {
  content: "+";
  position: absolute;
  right: 18px;
  top: 16px;
  font-family: var(--bsm-font-num);
  font-size: 22px;
  line-height: 1;
  color: var(--bsm-line);
}

.page-about .about-stage__box[open] > .about-stage__summary::after {
  content: "−";
  color: var(--bsm-flame);
}

.page-about .about-stage__summary:focus-visible {
  outline: 2px solid var(--bsm-teal);
  outline-offset: -3px;
}

.page-about .about-stage__index {
  font-family: var(--bsm-font-num);
  font-size: 20px;
  line-height: 1;
  letter-spacing: 0.06em;
  color: var(--bsm-flame);
}

.page-about .about-stage__meta {
  font-family: var(--bsm-font-accent);
  font-size: 12px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: #8a6a52;
}

.page-about .about-stage__title {
  flex: 1 1 100%;
  font-family: var(--bsm-font-serif);
  font-size: clamp(17px, 2.4vw, 22px);
  line-height: 1.4;
  color: var(--bsm-ink);
}

.page-about .about-stage__body {
  padding: 0 20px 22px;
}

.page-about .about-stage__body p {
  margin: 0;
  font-family: var(--bsm-font-sans);
  font-size: 15px;
  line-height: 1.85;
  color: #40352d;
}

.page-about .about-points {
  margin: 14px 0 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 8px;
}

.page-about .about-points li {
  position: relative;
  padding-left: 18px;
  font-family: var(--bsm-font-sans);
  font-size: 14px;
  line-height: 1.75;
  color: #4a3f38;
}

.page-about .about-points li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.78em;
  width: 10px;
  height: 2px;
  background: var(--bsm-teal);
}

.page-about .about-stage__figure {
  margin: 18px 0 0;
}

.page-about .about-stage__figure img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 2 / 1;
  object-fit: cover;
  clip-path: var(--bsm-cut-sm);
}

.page-about .about-stage__figure figcaption {
  margin-top: 8px;
  font-family: var(--bsm-font-sans);
  font-size: 13px;
  line-height: 1.7;
  color: #7a6857;
}

/* ---------- v3.2 对照 ---------- */
.page-about .about-version {
  background: var(--bsm-night);
  color: var(--bsm-paper);
}

.page-about .about-compare {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 18px;
  margin-top: clamp(24px, 4vw, 40px);
}

.page-about .about-compare__col {
  padding: 22px 22px 24px;
  clip-path: var(--bsm-cut);
  background: rgba(16, 42, 76, 0.86);
  border-top: 2px solid var(--bsm-line);
}

.page-about .about-compare__col--now {
  background: rgba(53, 240, 192, 0.08);
  border-top-color: var(--bsm-flame);
}

.page-about .about-compare__title {
  margin: 0 0 14px;
  font-family: var(--bsm-font-accent);
  font-size: 13px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--bsm-steel);
}

.page-about .about-compare__col--now .about-compare__title {
  color: var(--bsm-flame);
}

.page-about .about-compare__list {
  margin: 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 14px;
}

.page-about .about-compare__list li {
  position: relative;
  padding-left: 18px;
  font-family: var(--bsm-font-sans);
  font-size: 14px;
  line-height: 1.8;
  color: rgba(251, 247, 239, 0.82);
}

.page-about .about-compare__list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.8em;
  width: 8px;
  height: 8px;
  border: 1px solid var(--bsm-line);
  transform: rotate(45deg);
}

.page-about .about-compare__col--now .about-compare__list li::before {
  border-color: var(--bsm-teal);
  background: var(--bsm-teal);
}

.page-about .about-version__foot {
  display: grid;
  gap: 16px;
  margin-top: 26px;
  padding-top: 22px;
  border-top: 1px solid rgba(46, 74, 107, 0.9);
}

.page-about .about-version__foot p {
  margin: 0;
  font-family: var(--bsm-font-sans);
  font-size: 15px;
  line-height: 1.8;
  color: rgba(251, 247, 239, 0.78);
}

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

/* ---------- 团队 ---------- */
.page-about .about-team {
  background: var(--bsm-paper);
}

.page-about .about-team__inner {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(22px, 4vw, 40px);
  align-items: start;
}

.page-about .about-team__figure {
  margin: 0;
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 18px), calc(100% - 18px) 100%, 0 100%);
}

.page-about .about-team__figure img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 3 / 2;
  object-fit: cover;
}

.page-about .about-team__copy p {
  margin: 14px 0 0;
  font-family: var(--bsm-font-sans);
  font-size: 15px;
  line-height: 1.85;
  color: #4a3f38;
}

.page-about .about-team__title {
  margin: 12px 0 0;
  font-family: var(--bsm-font-serif);
  font-size: clamp(24px, 4vw, 34px);
  line-height: 1.28;
  color: var(--bsm-ink);
}

.page-about .about-review {
  position: relative;
  margin: 26px 0 0;
  padding: 22px 0 0;
  list-style: none;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 20px;
  border-top: 1px solid var(--bsm-line);
}

.page-about .about-review__step {
  position: relative;
  padding-left: 16px;
  border-left: 2px solid var(--bsm-teal);
}

.page-about .about-review__step:hover,
.page-about .about-review__step:focus-within {
  border-left-color: var(--bsm-flame);
}

.page-about .about-review__num {
  font-family: var(--bsm-font-num);
  font-size: 24px;
  line-height: 1;
  letter-spacing: 0.05em;
  color: var(--bsm-flame);
}

.page-about .about-review__name {
  margin: 8px 0 0;
  font-family: var(--bsm-font-serif);
  font-size: 18px;
  line-height: 1.35;
  color: var(--bsm-ink);
}

.page-about .about-review__desc {
  margin: 8px 0 0;
  font-family: var(--bsm-font-sans);
  font-size: 14px;
  line-height: 1.8;
  color: #5a4c41;
}

.page-about .about-team__tail {
  margin-top: 22px;
  padding-top: 16px;
  border-top: 1px dashed var(--about-line);
  color: #6a5849;
}

/* ---------- 下一步 ---------- */
.page-about .about-next {
  background: var(--bsm-cream);
}

.page-about .about-next__inner {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(20px, 4vw, 40px);
  align-items: start;
}

.page-about .about-next__title {
  margin: 12px 0 0;
  font-family: var(--bsm-font-serif);
  font-size: clamp(24px, 4vw, 34px);
  line-height: 1.28;
  color: var(--bsm-ink);
}

.page-about .about-next__copy p {
  margin: 14px 0 0;
  font-family: var(--bsm-font-sans);
  font-size: 15px;
  line-height: 1.85;
  color: #4a3f38;
}

.page-about .about-next__links {
  margin: 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 1px;
  background: var(--about-line);
}

.page-about .about-next__link {
  display: flex;
  align-items: baseline;
  gap: 14px;
  padding: 16px 18px;
  background: var(--bsm-paper);
  text-decoration: none;
  color: var(--bsm-ink);
  font-family: var(--bsm-font-sans);
  font-size: 15px;
  letter-spacing: 0.02em;
  transition: background 0.16s ease, color 0.16s ease;
}

.page-about .about-next__link:hover,
.page-about .about-next__link:focus-visible {
  background: var(--bsm-night);
  color: var(--bsm-paper);
}

.page-about .about-next__linknum {
  font-family: var(--bsm-font-num);
  font-size: 16px;
  color: var(--bsm-flame);
}

.page-about .about-next__link:hover .about-next__linknum,
.page-about .about-next__link:focus-visible .about-next__linknum {
  color: var(--bsm-teal);
}

/* ---------- 平板及以上 ---------- */
@media (min-width: 760px) {
  .page-about .about-hero__metrics {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .about-review {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 18px;
  }

  .page-about .about-compare {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 20px;
  }

  .page-about .about-version__foot {
    grid-template-columns: minmax(0, 1fr) auto;
    align-items: center;
  }
}

/* ---------- 桌面 ---------- */
@media (min-width: 900px) {
  .page-about .about-hero__inner {
    grid-template-columns: minmax(0, 1.1fr) minmax(0, 0.9fr);
    align-items: end;
    column-gap: clamp(32px, 5vw, 68px);
  }

  .page-about .about-crumb {
    grid-column: 1 / -1;
  }

  .page-about .about-hero__copy {
    padding-bottom: 8px;
  }

  .page-about .about-hero__figure {
    align-self: stretch;
  }

  .page-about .about-hero__metrics {
    grid-column: 1 / -1;
    margin-top: 10px;
  }
}

@media (min-width: 960px) {
  .page-about .about-timeline::before {
    left: 118px;
  }

  .page-about .about-stage {
    padding-left: 158px;
    margin-bottom: 20px;
  }

  .page-about .about-stage::before {
    left: 112px;
    top: 34px;
  }

  .page-about .about-stage__index {
    position: absolute;
    left: 0;
    top: 24px;
    font-size: 46px;
    color: rgba(36, 27, 22, 0.16);
    letter-spacing: 0.02em;
  }

  .page-about .about-stage--current .about-stage__index {
    color: rgba(255, 90, 54, 0.55);
  }

  .page-about .about-stage__summary {
    padding: 22px 52px 22px 26px;
    align-items: center;
  }

  .page-about .about-stage__title {
    flex: 1 1 auto;
  }

  .page-about .about-stage__summary::after {
    top: 22px;
    right: 22px;
  }

  .page-about .about-stage__body {
    padding: 0 26px 26px;
  }

  .page-about .about-team__inner {
    grid-template-columns: minmax(0, 0.85fr) minmax(0, 1.15fr);
    gap: clamp(32px, 5vw, 56px);
  }

  .page-about .about-next__inner {
    grid-template-columns: minmax(0, 1fr) minmax(0, 0.9fr);
    gap: clamp(32px, 5vw, 56px);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-stage__box,
  .page-about .about-next__link {
    transition: none;
  }
}
<<<END>>>