.page-about {
  --about-hair: rgba(53, 242, 214, 0.22);
  --about-hair-soft: rgba(244, 241, 234, 0.14);
  --about-glow: rgba(53, 242, 214, 0.10);
  background: var(--ink-900);
  color: var(--paper);
  overflow-x: hidden;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  padding-top: calc(var(--bar-h) + var(--rail-h) + clamp(32px, 7vw, 84px));
  padding-bottom: 0;
  background:
    radial-gradient(ellipse 70% 55% at 78% 8%, rgba(53, 242, 214, 0.13), transparent 65%),
    radial-gradient(ellipse 55% 45% at 8% 42%, rgba(255, 106, 43, 0.09), transparent 70%),
    linear-gradient(180deg, var(--ink-900) 0%, var(--ink-700) 100%);
  isolation: isolate;
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(to right, rgba(53, 242, 214, 0.07) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(53, 242, 214, 0.07) 1px, transparent 1px);
  background-size: 78px 78px;
  -webkit-mask-image: radial-gradient(ellipse 85% 70% at 60% 0%, #000 0%, transparent 78%);
  mask-image: radial-gradient(ellipse 85% 70% at 60% 0%, #000 0%, transparent 78%);
  pointer-events: none;
  z-index: -1;
}

.page-about .about-hero__crumb {
  margin-bottom: clamp(28px, 5vw, 56px);
  font-size: 13px;
  letter-spacing: 0.04em;
  color: var(--gray-500);
}

.page-about .about-hero__layout {
  display: grid;
  grid-template-columns: 1fr;
  gap: 20px;
  align-items: end;
}

.page-about .about-hero__title {
  margin: 14px 0 0;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(40px, 8.5vw, 88px);
  line-height: 1.04;
  letter-spacing: -0.02em;
  color: var(--paper);
}

.page-about .about-hero__title br {
  display: none;
}

.page-about .about-hero__lede {
  margin: 22px 0 0;
  max-width: 36em;
  font-size: 16px;
  line-height: 1.78;
  color: rgba(244, 241, 234, 0.82);
}

.page-about .about-hero__annot {
  color: var(--cyan-300);
  opacity: 0.82;
}

.page-about .about-hero__stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: clamp(32px, 6vw, 60px) 0 0;
  padding: 0;
  list-style: none;
  border-top: 1px solid var(--about-hair-soft);
}

.page-about .about-stat {
  padding: 20px 4px 22px;
  border-top: 1px solid transparent;
  margin-top: -1px;
  position: relative;
}

.page-about .about-stat::before {
  content: "";
  position: absolute;
  top: -1px;
  left: 0;
  width: 26px;
  height: 1px;
  background: var(--cyan-400);
}

.page-about .about-stat dt {
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--gray-500);
}

.page-about .about-stat dd {
  margin: 8px 0 0;
  font-size: 14px;
  color: rgba(244, 241, 234, 0.72);
}

.page-about .about-stat__num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-weight: 600;
  font-size: clamp(30px, 5vw, 42px);
  line-height: 1;
  color: var(--cyan-400);
  margin-right: 6px;
}

.page-about .about-hero__figure {
  margin: clamp(32px, 6vw, 64px) 0 0;
  position: relative;
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 48px), 0 100%);
}

.page-about .about-hero__figure img {
  display: block;
  width: 100%;
  height: auto;
  max-width: 100%;
  object-fit: cover;
  filter: saturate(0.85) brightness(0.72);
}

/* ---------- 章节通用头部 ---------- */
.page-about .about-head {
  display: grid;
  grid-template-columns: 1fr;
  gap: 10px;
  margin-bottom: clamp(32px, 5vw, 56px);
}

.page-about .about-head__idx {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-weight: 600;
  font-size: clamp(46px, 10vw, 104px);
  line-height: 0.85;
  color: transparent;
  -webkit-text-stroke: 1px rgba(53, 242, 214, 0.45);
  letter-spacing: -0.04em;
}

.page-about .about-head__title {
  margin: 12px 0 0;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(30px, 5.6vw, 56px);
  line-height: 1.08;
  letter-spacing: -0.02em;
}

.page-about .about-head__title br {
  display: none;
}

.page-about .about-head__annot {
  color: var(--gray-500);
}

/* ---------- 01 流程 ---------- */
.page-about .about-flow {
  background: var(--paper);
  color: var(--ink-900);
}

.page-about .about-flow .sb-eyebrow,
.page-about .about-flow .about-head__annot {
  color: #4C5D5A;
}

.page-about .about-flow .about-head__idx {
  -webkit-text-stroke: 1px rgba(6, 17, 15, 0.28);
}

.page-about .about-flow .about-head__title {
  color: var(--ink-900);
}

.page-about .about-flow__layout {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(28px, 4vw, 48px);
}

.page-about .about-flow__steps {
  position: relative;
  margin: 0;
  padding: 0 0 0 34px;
  list-style: none;
  display: grid;
  gap: clamp(22px, 3.4vw, 32px);
}

.page-about .about-flow__steps::before {
  content: "";
  position: absolute;
  left: 9px;
  top: 8px;
  bottom: 8px;
  width: 1px;
  background: linear-gradient(180deg, var(--cyan-400), rgba(255, 106, 43, 0.65) 55%, rgba(6, 17, 15, 0.12));
}

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

.page-about .about-step::before {
  content: "";
  position: absolute;
  left: -30px;
  top: 7px;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--paper);
  border: 1.5px solid var(--ink-900);
}

.page-about .about-step--key::before {
  background: var(--cyan-400);
  border-color: var(--cyan-400);
  box-shadow: 0 0 0 4px rgba(53, 242, 214, 0.28);
}

.page-about .about-step__no {
  display: block;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.16em;
  color: #6F817E;
}

.page-about .about-step__title {
  margin: 4px 0 6px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(20px, 3vw, 24px);
  line-height: 1.2;
  color: var(--ink-900);
}

.page-about .about-step__text {
  margin: 0;
  max-width: 34em;
  font-size: 15.5px;
  line-height: 1.78;
  color: #2B3B38;
}

.page-about .about-flow__figure {
  margin: 0;
  position: relative;
  border-radius: var(--radius);
  overflow: hidden;
  background: var(--ink-700);
}

.page-about .about-flow__figure img {
  display: block;
  width: 100%;
  height: auto;
  max-width: 100%;
  object-fit: cover;
  aspect-ratio: 4 / 5;
}

.page-about .about-flow__cap {
  position: absolute;
  left: 0;
  bottom: 0;
  padding: 10px 14px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.08em;
  color: var(--cyan-300);
  background: rgba(6, 17, 15, 0.78);
}

/* ---------- 02 时间刻度 ---------- */
.page-about .about-clock {
  background: linear-gradient(180deg, var(--ink-900) 0%, var(--ink-800) 100%);
}

.page-about .about-clock__list {
  display: grid;
  grid-template-columns: 1fr;
  gap: 26px;
  margin: 0;
  padding: 0 0 0 24px;
  list-style: none;
  position: relative;
  border-left: 1px solid var(--about-hair);
}

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

.page-about .about-tick::before {
  content: "";
  position: absolute;
  left: -29px;
  top: 6px;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--orange-500);
  box-shadow: 0 0 0 4px rgba(255, 106, 43, 0.16);
}

.page-about .about-tick__time {
  display: inline-block;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 13px;
  letter-spacing: 0.06em;
  color: var(--orange-300);
  padding: 3px 8px;
  border: 1px solid rgba(255, 106, 43, 0.35);
  border-radius: 999px;
}

.page-about .about-tick__title {
  margin: 10px 0 6px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 20px;
  line-height: 1.25;
  color: var(--paper);
}

.page-about .about-tick__text {
  margin: 0;
  max-width: 30em;
  font-size: 15px;
  line-height: 1.76;
  color: rgba(244, 241, 234, 0.72);
}

/* ---------- 03 项目小组 ---------- */
.page-about .about-units {
  background: var(--ink-800);
}

.page-about .about-units__lede {
  margin: 0 0 clamp(28px, 4vw, 44px);
  max-width: 36em;
  font-size: 16px;
  line-height: 1.8;
  color: rgba(244, 241, 234, 0.76);
}

.page-about .about-units__list {
  margin: 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 2px;
}

.page-about .about-unit {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 16px;
  align-items: start;
  padding: 20px 16px;
  border-radius: var(--radius);
  background: rgba(14, 42, 36, 0.55);
  transition: background 220ms var(--ease), transform 220ms var(--ease);
}

.page-about .about-unit:hover {
  background: rgba(53, 242, 214, 0.09);
  transform: translateX(3px);
}

.page-about .about-unit__count {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-weight: 600;
  font-size: clamp(30px, 5vw, 40px);
  line-height: 0.95;
  color: var(--cyan-400);
  min-width: 1.3em;
}

.page-about .about-unit__name {
  margin: 0 0 6px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 19px;
  line-height: 1.25;
  color: var(--paper);
}

.page-about .about-unit__text {
  margin: 0;
  max-width: 34em;
  font-size: 15px;
  line-height: 1.74;
  color: rgba(244, 241, 234, 0.7);
}

/* ---------- 04 版本演进 ---------- */
.page-about .about-vers {
  background: var(--ink-900);
}

.page-about .about-vers__list {
  margin: 0;
  padding: 0 0 0 26px;
  list-style: none;
  position: relative;
  display: grid;
  gap: 10px;
  border-left: 1px solid var(--about-hair);
}

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

.page-about .about-ver::before {
  content: "";
  position: absolute;
  left: -31px;
  top: 20px;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--ink-900);
  border: 1.5px solid var(--cyan-400);
}

.page-about .about-ver details[open]::before {
  background: var(--cyan-400);
}

.page-about .about-ver__sum {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 10px;
  padding: 12px 14px;
  cursor: pointer;
  list-style: none;
  border-radius: var(--radius);
  border: 1px solid transparent;
  transition: background 200ms var(--ease), border-color 200ms var(--ease);
}

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

.page-about .about-ver__sum::after {
  content: "＋";
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: 15px;
  color: var(--cyan-400);
}

.page-about .about-ver details[open] > .about-ver__sum::after {
  content: "－";
  color: var(--orange-500);
}

.page-about .about-ver__sum:hover,
.page-about .about-ver__sum:focus-visible {
  background: rgba(53, 242, 214, 0.07);
  border-color: var(--about-hair);
  outline: none;
}

.page-about .about-ver__sum:focus-visible {
  outline: 2px solid var(--cyan-400);
  outline-offset: 2px;
}

.page-about .about-ver__tag {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-weight: 600;
  font-size: 14px;
  letter-spacing: 0.06em;
  color: var(--orange-300);
  min-width: 2.4em;
}

.page-about .about-ver__name {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(18px, 2.8vw, 22px);
  letter-spacing: -0.01em;
  color: var(--paper);
}

.page-about .about-ver__hint {
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.1em;
  color: var(--gray-500);
  width: 100%;
}

.page-about .about-ver__panel {
  padding: 4px 14px 18px calc(2.4em + 10px);
}

.page-about .about-ver__panel p {
  margin: 0;
  max-width: 34em;
  font-size: 15px;
  line-height: 1.78;
  color: rgba(244, 241, 234, 0.72);
}

/* ---------- 05 合作生态 ---------- */
.page-about .about-eco {
  position: relative;
  background: linear-gradient(160deg, var(--ink-700) 0%, var(--ink-800) 62%, var(--ink-900) 100%);
  overflow: hidden;
}

.page-about .about-eco__bg {
  position: absolute;
  inset: 0;
  z-index: 0;
  pointer-events: none;
}

.page-about .about-eco__bg img {
  width: 100%;
  height: 100%;
  max-width: 100%;
  object-fit: cover;
  opacity: 0.18;
  filter: saturate(0.6);
}

.page-about .about-eco__inner {
  position: relative;
  z-index: 1;
}

.page-about .about-eco__stamps {
  display: grid;
  grid-template-columns: 1fr;
  gap: 18px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .about-stamp {
  padding: 22px 20px 24px;
  border-radius: 18px 4px 18px 4px;
  border: 1px solid var(--about-hair);
  background: rgba(6, 17, 15, 0.62);
  transition: border-color 220ms var(--ease), transform 220ms var(--ease), background 220ms var(--ease);
}

.page-about .about-stamp--a {
  transform: rotate(-1.4deg);
  border-color: rgba(53, 242, 214, 0.4);
}

.page-about .about-stamp--b {
  transform: rotate(1.1deg);
  border-color: rgba(255, 106, 43, 0.38);
}

.page-about .about-stamp--c {
  transform: rotate(-0.8deg);
}

.page-about .about-stamp:hover,
.page-about .about-stamp:focus-within {
  transform: rotate(0deg) translateY(-3px);
  background: rgba(14, 42, 36, 0.9);
  border-color: var(--cyan-400);
}

.page-about .about-stamp__num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-weight: 600;
  font-size: clamp(38px, 6vw, 52px);
  line-height: 1;
  color: var(--cyan-400);
}

.page-about .about-stamp--b .about-stamp__num {
  color: var(--orange-500);
}

.page-about .about-stamp__unit {
  font-size: 13px;
  color: var(--gray-500);
  margin-left: 4px;
}

.page-about .about-stamp__name {
  margin: 12px 0 8px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 18px;
  color: var(--paper);
}

.page-about .about-stamp__text {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.74;
  color: rgba(244, 241, 234, 0.7);
  max-height: 0;
  opacity: 0;
  overflow: hidden;
  transition: max-height 260ms var(--ease), opacity 260ms var(--ease), margin 260ms var(--ease);
}

.page-about .about-stamp:hover .about-stamp__text,
.page-about .about-stamp:focus-within .about-stamp__text,
.page-about .about-stamp:active .about-stamp__text {
  max-height: 8em;
  opacity: 1;
  margin-top: 4px;
}

.page-about .about-eco__more {
  margin: clamp(26px, 4vw, 40px) 0 0;
  max-width: 36em;
  font-size: 15.5px;
  line-height: 1.8;
  color: rgba(244, 241, 234, 0.76);
}

.page-about .about-eco__link {
  color: var(--cyan-400);
  text-decoration: none;
  border-bottom: 1px solid rgba(53, 242, 214, 0.45);
  margin-left: 6px;
  white-space: nowrap;
}

.page-about .about-eco__link:hover,
.page-about .about-eco__link:focus-visible {
  color: var(--cyan-300);
  border-bottom-color: var(--cyan-300);
  outline: none;
}

/* ---------- 06 认可 ---------- */
.page-about .about-honor {
  background: var(--paper);
  color: var(--ink-900);
}

.page-about .about-honor .sb-eyebrow,
.page-about .about-honor .about-head__annot {
  color: #4C5D5A;
}

.page-about .about-honor .about-head__idx {
  -webkit-text-stroke: 1px rgba(6, 17, 15, 0.28);
}

.page-about .about-honor .about-head__title {
  color: var(--ink-900);
}

.page-about .about-honor__list {
  display: grid;
  grid-template-columns: 1fr;
  gap: 26px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .about-honor__item {
  border-top: 1px solid rgba(6, 17, 15, 0.14);
  padding-top: 18px;
}

.page-about .about-honor__item h3 {
  margin: 0 0 8px;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-weight: 600;
  font-size: clamp(22px, 3.6vw, 30px);
  line-height: 1.1;
  letter-spacing: -0.01em;
  color: var(--ink-900);
}

.page-about .about-honor__item p {
  margin: 0;
  max-width: 26em;
  font-size: 15px;
  line-height: 1.76;
  color: #33433F;
}

/* ---------- 结尾行动 ---------- */
.page-about .about-cta {
  background:
    radial-gradient(ellipse 65% 80% at 88% 20%, rgba(53, 242, 214, 0.14), transparent 68%),
    linear-gradient(180deg, var(--ink-900) 0%, var(--ink-700) 100%);
}

.page-about .about-cta__inner {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(26px, 4vw, 48px);
  align-items: start;
}

.page-about .about-cta__title {
  margin: 12px 0 0;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(28px, 5.2vw, 48px);
  line-height: 1.1;
  letter-spacing: -0.02em;
  color: var(--paper);
}

.page-about .about-cta__title br {
  display: none;
}

.page-about .about-cta__text {
  margin: 18px 0 0;
  max-width: 34em;
  font-size: 15.5px;
  line-height: 1.8;
  color: rgba(244, 241, 234, 0.74);
}

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

.page-about .about-cta__actions .sb-btn {
  flex: 1 1 140px;
  justify-content: center;
  text-align: center;
}

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

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

  .page-about .about-honor__list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 30px 40px;
  }
}

@media (min-width: 900px) {
  .page-about .about-hero__title br,
  .page-about .about-head__title br,
  .page-about .about-cta__title br {
    display: inline;
  }

  .page-about .about-hero__layout {
    grid-template-columns: minmax(0, 1fr) auto;
    gap: 48px;
  }

  .page-about .about-hero__annot {
    writing-mode: vertical-rl;
    font-size: 12px;
    letter-spacing: 0.22em;
    padding-bottom: 8px;
    align-self: end;
  }

  .page-about .about-hero__figure {
    clip-path: polygon(0 0, 100% 0, 100% calc(100% - 84px), 0 100%);
  }

  .page-about .about-head {
    grid-template-columns: clamp(90px, 12vw, 150px) minmax(0, 1fr) auto;
    gap: 32px;
    align-items: start;
  }

  .page-about .about-head__annot {
    writing-mode: vertical-rl;
    font-size: 12px;
    letter-spacing: 0.2em;
    max-height: 220px;
    padding-top: 6px;
  }

  .page-about .about-flow__layout {
    grid-template-columns: minmax(0, 1.35fr) minmax(0, 0.85fr);
    gap: clamp(40px, 5vw, 72px);
    align-items: start;
  }

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

  .page-about .about-clock__list {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 32px;
    padding: 40px 0 0;
    border-left: 0;
    border-top: 1px solid var(--about-hair);
  }

  .page-about .about-tick::before {
    left: 0;
    top: -45px;
  }

  .page-about .about-unit {
    grid-template-columns: 110px minmax(0, 1fr);
    gap: 24px;
    padding: 24px 20px;
  }

  .page-about .about-vers__list {
    padding-left: 34px;
  }

  .page-about .about-ver::before {
    left: -39px;
    top: 24px;
  }

  .page-about .about-ver__sum {
    align-items: center;
    padding: 14px 18px;
  }

  .page-about .about-ver__hint {
    width: auto;
    margin-left: 6px;
  }

  .page-about .about-ver__panel {
    padding-left: 5.4em;
  }

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

  .page-about .about-cta__inner {
    grid-template-columns: minmax(0, 1.15fr) minmax(0, 0.85fr);
    align-items: center;
  }

  .page-about .about-cta__actions {
    justify-content: flex-end;
  }

  .page-about .about-cta__actions .sb-btn {
    flex: 0 0 auto;
  }
}

@media (min-width: 1180px) {
  .page-about .about-hero__title {
    font-size: clamp(64px, 6.6vw, 92px);
  }

  .page-about .about-flow__figure img {
    aspect-ratio: 4 / 5;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-unit,
  .page-about .about-stamp,
  .page-about .about-stamp__text,
  .page-about .about-ver__sum {
    transition: none;
  }
}