.page-about {
  background: var(--paper);
  color: var(--brown);
  -webkit-font-smoothing: antialiased;
}

/* ---------- 面包屑 ---------- */
.page-about .crumbs {
  font-size: var(--t-14);
}
.page-about .crumbs ol {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: .35rem;
  margin: 0;
  padding: 0;
  list-style: none;
}
.page-about .crumbs li {
  color: var(--vein);
}
.page-about .crumbs li + li::before {
  content: "/";
  margin-right: .35rem;
  color: var(--hair-strong);
}
.page-about .crumbs a {
  color: var(--brown);
  text-decoration: none;
  border-bottom: 1px solid var(--hair-strong);
  padding-bottom: 1px;
  transition: border-color .18s var(--ease);
}
.page-about .crumbs a:hover {
  border-bottom-color: var(--flesh);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  padding: clamp(22px, 3.6vw, 40px) 0 clamp(44px, 6.5vw, 84px);
}
.page-about .about-hero::before {
  content: "";
  position: absolute;
  top: -24%;
  right: -12%;
  width: clamp(280px, 44vw, 620px);
  aspect-ratio: 1 / 1;
  border-radius: 52% 48% 44% 56% / 48% 44% 56% 52%;
  background: radial-gradient(circle at 36% 30%, rgba(123, 192, 67, .28), rgba(220, 235, 200, .55) 52%, rgba(244, 238, 226, 0) 74%);
  pointer-events: none;
}
.page-about .about-hero .wrap {
  position: relative;
  z-index: 1;
}
.page-about .about-hero .eyebrow {
  margin-top: clamp(20px, 3vw, 34px);
}
.page-about .about-hero h1 {
  margin: clamp(12px, 1.8vw, 20px) 0 0;
  max-width: 16ch;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(2.3rem, 6.6vw, 5.2rem);
  line-height: 1.04;
  letter-spacing: -.035em;
  color: var(--seed);
}
.page-about .about-hero .lede {
  margin: clamp(18px, 2.4vw, 30px) 0 0;
  max-width: 33ch;
  font-size: var(--t-21);
  line-height: 1.72;
  color: var(--brown);
}
.page-about .hero-facts {
  margin: clamp(30px, 4.4vw, 54px) 0 0;
  padding: clamp(18px, 2.4vw, 26px) 0 0;
  border-top: 1px solid var(--hair);
  list-style: none;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: clamp(16px, 3vw, 30px);
}
.page-about .hero-facts__num {
  display: block;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: var(--t-40);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -.02em;
  color: var(--seed);
}
.page-about .hero-facts__label {
  display: block;
  margin-top: 8px;
  font-size: var(--t-14);
  line-height: 1.5;
  letter-spacing: .02em;
  color: var(--vein);
}

/* ---------- 骨架与章节索引 ---------- */
.page-about .about-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(28px, 4vw, 56px);
  padding-bottom: clamp(56px, 8vw, 112px);
}
.page-about .about-body {
  min-width: 0;
}
.page-about .about-index {
  display: none;
}
.page-about .about-index__label {
  margin: 0 0 14px;
  font-family: var(--font-serif);
  font-size: var(--t-14);
  letter-spacing: .18em;
  color: var(--vein);
}
.page-about .about-index__list {
  margin: 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 8px;
}
.page-about .about-index__list a {
  display: flex;
  gap: 8px;
  align-items: baseline;
  padding: 3px 0;
  font-size: var(--t-14);
  line-height: 1.45;
  color: var(--brown);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color .18s var(--ease), border-color .18s var(--ease);
}
.page-about .about-index__list a .num {
  font-size: var(--t-12);
  color: var(--vein);
}
.page-about .about-index__list a:hover {
  color: var(--sun);
  border-bottom-color: rgba(240, 120, 45, .5);
}

/* ---------- 章节 ---------- */
.page-about .chapter {
  scroll-margin-top: 96px;
}
.page-about .chapter + .chapter {
  margin-top: clamp(72px, 11vw, 148px);
}
.page-about .chapter__head {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  align-items: end;
  gap: clamp(12px, 2vw, 26px);
  padding-bottom: clamp(10px, 1.6vw, 18px);
  border-bottom: 1px solid var(--hair);
}
.page-about .chapter__num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: clamp(2.2rem, 6vw, 3.9rem);
  font-weight: 700;
  line-height: .84;
  letter-spacing: -.05em;
  color: rgba(123, 192, 67, .6);
}
.page-about .chapter__title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(1.5rem, 3.4vw, 2.5rem);
  line-height: 1.2;
  letter-spacing: -.02em;
  color: var(--seed);
}
.page-about .chapter__body,
.page-about .chapter__split {
  margin-top: clamp(22px, 3vw, 36px);
}
.page-about .chapter__body p,
.page-about .chapter__text p {
  max-width: 34ch;
  margin: 0 0 1.1em;
  font-size: var(--t-17);
  line-height: 1.85;
  color: var(--brown);
}
.page-about .chapter__body p:last-child,
.page-about .chapter__text p:last-child {
  margin-bottom: 0;
}
.page-about .chapter__split {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(22px, 3.4vw, 44px);
  align-items: start;
}

/* ---------- 图片 ---------- */
.page-about .about-figure {
  margin: 0;
}
.page-about .about-figure img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
  border-radius: var(--radius-card);
  background: var(--cream);
}
.page-about .about-figure figcaption {
  margin-top: 10px;
  font-family: var(--font-serif);
  font-size: var(--t-14);
  line-height: 1.7;
  color: var(--vein);
}
.page-about .about-figure--portrait img {
  aspect-ratio: 3 / 4;
  box-shadow: 0 0 0 1px rgba(200, 255, 87, .9), var(--shadow-float);
}
.page-about .about-figure--square {
  max-width: 440px;
  margin: clamp(28px, 4vw, 48px) auto 0;
}
.page-about .about-figure--square img {
  aspect-ratio: 1 / 1;
  box-shadow: 0 0 0 1px rgba(58, 49, 40, .14);
}
.page-about .about-figure--wide {
  margin-top: clamp(30px, 4.4vw, 54px);
}
.page-about .about-figure--wide img {
  aspect-ratio: 2 / 1;
  box-shadow: 0 0 0 1px rgba(200, 255, 87, .8), var(--shadow-float);
}

/* ---------- 团队分工 ---------- */
.page-about .team-list {
  margin: clamp(22px, 3vw, 34px) 0 0;
  display: grid;
}
.page-about .team-list__row {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 6px;
  padding: clamp(14px, 2vw, 20px) 0;
  border-top: 1px solid var(--hair);
}
.page-about .team-list__row:last-child {
  border-bottom: 1px solid var(--hair);
}
.page-about .team-list dt {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: var(--t-17);
  letter-spacing: .01em;
  color: var(--seed);
}
.page-about .team-list dd {
  margin: 0;
  max-width: 36ch;
  font-size: var(--t-17);
  line-height: 1.8;
  color: var(--brown);
}

/* ---------- 上线四道手 ---------- */
.page-about .run-flow {
  margin: clamp(28px, 4vw, 46px) 0 0;
  padding: 0;
  list-style: none;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: clamp(14px, 2.4vw, 22px);
}
.page-about .run-flow li {
  display: grid;
  gap: 5px;
  padding-top: 12px;
  border-top: 2px solid var(--flesh);
  font-size: var(--t-14);
  line-height: 1.5;
  color: var(--brown);
}
.page-about .run-flow__n {
  font-family: var(--font-mono);
  font-size: var(--t-12);
  letter-spacing: .12em;
  color: var(--sun);
}

/* ---------- 双轨视觉演示 ---------- */
.page-about .tone-switch {
  margin: clamp(24px, 3.4vw, 40px) 0;
  position: relative;
}
.page-about .tone-input {
  position: absolute;
  width: 1px;
  height: 1px;
  opacity: 0;
  pointer-events: none;
}
.page-about .tone-options {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 14px;
}
.page-about .tone-label {
  cursor: pointer;
  padding: 8px 18px;
  border-radius: var(--radius-pill);
  border: 1px solid var(--hair-strong);
  background: transparent;
  color: var(--brown);
  font-size: var(--t-14);
  font-weight: 700;
  letter-spacing: .02em;
  transition: background-color .18s var(--ease), color .18s var(--ease), border-color .18s var(--ease);
}
.page-about .tone-label:hover {
  border-color: var(--seed);
}
.page-about .tone-input:focus-visible ~ .tone-options .tone-label {
  outline: 2px solid var(--neon);
  outline-offset: 3px;
}
.page-about .tone-stage {
  display: grid;
}
.page-about .tone-panel {
  grid-area: 1 / 1;
  padding: clamp(20px, 3.2vw, 34px);
  border-radius: var(--radius-soft);
  opacity: 0;
  pointer-events: none;
  transition: opacity .22s var(--ease);
}
.page-about .tone-panel__kicker {
  margin: 0 0 14px;
  font-size: var(--t-12);
  letter-spacing: .2em;
  text-transform: uppercase;
}
.page-about .tone-panel__big {
  margin: 0;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: clamp(2.3rem, 6vw, 3.8rem);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -.03em;
}
.page-about .tone-panel__big .unit {
  margin-left: .3em;
  font-family: var(--font-body);
  font-size: var(--t-17);
  font-weight: 400;
}
.page-about .tone-panel__serif {
  margin: 0 0 16px;
  max-width: 24ch;
  font-family: var(--font-serif);
  font-size: var(--t-21);
  line-height: 1.9;
}
.page-about .tone-panel__note {
  margin: 16px 0 0;
  max-width: 32ch;
  font-size: var(--t-14);
  line-height: 1.8;
}
.page-about .tone-panel--dark {
  background: var(--seed);
  color: var(--paper);
  box-shadow: var(--shadow-float);
}
.page-about .tone-panel--dark .tone-panel__kicker {
  color: rgba(200, 255, 87, .8);
}
.page-about .tone-panel--dark .tone-panel__big {
  color: var(--neon);
}
.page-about .tone-panel--dark .tone-panel__big .unit {
  color: rgba(200, 255, 87, .6);
}
.page-about .tone-panel--dark .tone-panel__note {
  color: rgba(244, 238, 226, .72);
}
.page-about .tone-panel--light {
  background: var(--salt);
  border: 1px solid var(--hair);
}
.page-about .tone-panel--light .tone-panel__kicker {
  color: var(--vein);
}
.page-about .tone-panel--light .tone-panel__serif {
  color: var(--brown);
}
.page-about .tone-panel--light .tone-panel__note {
  color: var(--vein);
}
.page-about #tone-dark:checked ~ .tone-stage .tone-panel--dark,
.page-about #tone-light:checked ~ .tone-stage .tone-panel--light {
  opacity: 1;
  pointer-events: auto;
}
.page-about #tone-dark:checked ~ .tone-options .tone-label[for="tone-dark"] {
  background: var(--seed);
  color: var(--neon);
  border-color: var(--seed);
}
.page-about #tone-light:checked ~ .tone-options .tone-label[for="tone-light"] {
  background: var(--salt);
  color: var(--seed);
  border-color: var(--seed);
}

/* ---------- 节奏 ---------- */
.page-about .cadence {
  margin: clamp(24px, 3.4vw, 40px) 0 clamp(24px, 3.4vw, 38px);
  padding: 0;
  list-style: none;
  display: grid;
  gap: clamp(20px, 3vw, 30px);
}
.page-about .cadence > li {
  padding-top: clamp(14px, 2vw, 20px);
  border-top: 2px solid var(--seed);
}
.page-about .cadence__num {
  display: inline-block;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: clamp(1.9rem, 4.4vw, 3rem);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -.03em;
  color: var(--seed);
}
.page-about .cadence__unit {
  margin-left: .3em;
  font-size: var(--t-14);
  color: var(--vein);
}
.page-about .cadence__text {
  margin: 12px 0 0;
  max-width: 30ch;
  font-size: var(--t-17);
  line-height: 1.8;
  color: var(--brown);
}

/* ---------- 覆盖范围 ---------- */
.page-about .cover-tags {
  margin: clamp(18px, 2.4vw, 26px) 0 clamp(18px, 2.4vw, 26px);
  padding: 0;
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

/* ---------- 里程碑时间线 ---------- */
.page-about .about-timeline {
  --tl-pad: clamp(20px, 3vw, 30px);
  position: relative;
  margin: clamp(24px, 3.4vw, 40px) 0 0;
  padding: 0 0 0 var(--tl-pad);
  list-style: none;
}
.page-about .about-timeline::before {
  content: "";
  position: absolute;
  left: 5px;
  top: 8px;
  bottom: 8px;
  width: 2px;
  border-radius: 2px;
  background: linear-gradient(180deg, var(--flesh), rgba(123, 192, 67, .22));
}
.page-about .about-timeline__item {
  position: relative;
  padding-bottom: clamp(26px, 4vw, 40px);
}
.page-about .about-timeline__item:last-child {
  padding-bottom: 0;
}
.page-about .about-timeline__item::before {
  content: "";
  position: absolute;
  top: 8px;
  left: calc(-1 * var(--tl-pad));
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--sun);
  box-shadow: 0 0 0 4px var(--paper), 0 0 0 5px rgba(240, 120, 45, .35);
  transition: transform .18s var(--ease), box-shadow .18s var(--ease);
}
.page-about .about-timeline__item:hover::before {
  transform: scale(1.22);
  box-shadow: 0 0 0 4px var(--paper), 0 0 0 6px rgba(240, 120, 45, .55);
}
.page-about .about-timeline__year {
  margin: 0;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: var(--t-21);
  font-weight: 700;
  letter-spacing: -.01em;
  color: var(--seed);
}
.page-about .about-timeline__title {
  margin: 4px 0 6px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: var(--t-17);
  line-height: 1.4;
  color: var(--seed);
}
.page-about .about-timeline__text {
  margin: 0;
  max-width: 34ch;
  font-size: var(--t-17);
  line-height: 1.8;
  color: var(--brown);
}

/* ---------- 结尾引导 ---------- */
.page-about .about-cta {
  margin-top: clamp(60px, 9vw, 120px);
}
.page-about .about-cta__inner {
  display: grid;
  gap: clamp(20px, 3vw, 32px);
  padding: clamp(24px, 4vw, 44px);
  border: 1px solid var(--hair);
  border-radius: var(--radius-soft);
  background: linear-gradient(120deg, rgba(220, 235, 200, .9), rgba(252, 251, 247, .5) 62%), var(--salt);
}
.page-about .about-cta h2 {
  margin: 10px 0 0;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(1.35rem, 2.8vw, 2rem);
  line-height: 1.3;
  letter-spacing: -.02em;
  color: var(--seed);
  max-width: 22ch;
}
.page-about .about-cta__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

/* ---------- 断点 ---------- */
@media (min-width: 640px) {
  .page-about .team-list__row {
    grid-template-columns: 130px minmax(0, 1fr);
    gap: clamp(16px, 3vw, 32px);
    align-items: baseline;
  }
}

@media (min-width: 720px) {
  .page-about .chapter__split {
    grid-template-columns: minmax(0, 1fr) minmax(0, 248px);
  }
  .page-about .chapter__split .about-figure {
    margin-top: clamp(0px, 2.4vw, 46px);
  }
}

@media (min-width: 760px) {
  .page-about .hero-facts {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
  .page-about .run-flow {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
  .page-about .about-cta__inner {
    grid-template-columns: minmax(0, 1fr) auto;
    align-items: center;
  }
}

@media (min-width: 840px) {
  .page-about .cadence {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

@media (min-width: 1024px) {
  .page-about .about-layout {
    grid-template-columns: minmax(0, 1fr) 172px;
    gap: clamp(40px, 5vw, 76px);
  }
  .page-about .about-index {
    display: block;
    position: sticky;
    top: 112px;
    align-self: start;
    padding-left: 16px;
    border-left: 1px solid var(--hair);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .tone-panel,
  .page-about .tone-label,
  .page-about .about-index__list a,
  .page-about .about-timeline__item::before,
  .page-about .crumbs a {
    transition: none;
  }
  .page-about .about-timeline__item:hover::before {
    transform: none;
  }
}