.page-about {
  --ab-paper-line: rgba(38, 51, 58, .14);
  --ab-deep-line: rgba(224, 172, 99, .22);
  --ab-gap: clamp(56px, 8vw, 112px);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  isolation: isolate;
  overflow: hidden;
  background: var(--ky-copper-900);
  color: var(--ky-paper);
  padding-block: clamp(36px, 6vw, 72px) clamp(48px, 8vw, 100px);
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: -2;
  background-image:
    linear-gradient(to right, rgba(224, 172, 99, .09) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(224, 172, 99, .09) 1px, transparent 1px);
  background-size: 76px 76px;
  -webkit-mask-image: radial-gradient(120% 90% at 20% 0%, #000 20%, transparent 78%);
  mask-image: radial-gradient(120% 90% at 20% 0%, #000 20%, transparent 78%);
  pointer-events: none;
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  z-index: -1;
  top: -26vw;
  right: -18vw;
  width: 70vw;
  height: 70vw;
  max-width: 820px;
  max-height: 820px;
  background: radial-gradient(circle at center, rgba(122, 92, 255, .40), rgba(31, 182, 196, .14) 46%, transparent 70%);
  pointer-events: none;
}

.page-about .about-hero__inner {
  display: grid;
  gap: clamp(30px, 5vw, 52px);
}

.page-about .about-hero__crumb {
  margin-bottom: 22px;
}

.page-about .about-hero__crumb .ky-breadcrumb__item,
.page-about .about-hero__crumb .ky-breadcrumb__item a {
  color: rgba(246, 241, 231, .72);
}

.page-about .about-hero__crumb .ky-breadcrumb__item a:hover,
.page-about .about-hero__crumb .ky-breadcrumb__item a:focus-visible {
  color: var(--ky-copper-300);
}

.page-about .about-hero__eyebrow {
  margin: 0 0 18px;
  color: var(--ky-copper-300);
  letter-spacing: .2em;
}

.page-about .about-hero__title {
  margin: 0;
  font-family: var(--ky-font-display);
  font-weight: 300;
  font-size: clamp(42px, 9vw, 88px);
  line-height: 1.06;
  letter-spacing: -.02em;
  color: var(--ky-paper);
}

.page-about .about-hero__lede {
  margin: 24px 0 0;
  max-width: 34em;
  color: rgba(246, 241, 231, .84);
}

.page-about .about-hero__index {
  list-style: none;
  margin: 34px 0 0;
  padding: 0;
  display: grid;
  gap: 2px;
}

.page-about .about-hero__index a {
  display: flex;
  align-items: baseline;
  gap: 14px;
  padding: 10px 12px 10px 0;
  border-left: 2px solid var(--ab-deep-line);
  padding-left: 14px;
  color: rgba(246, 241, 231, .8);
  text-decoration: none;
  font-size: 15px;
  transition: color 200ms var(--ky-ease), border-color 200ms var(--ky-ease), padding-left 200ms var(--ky-ease);
}

.page-about .about-hero__index a:hover,
.page-about .about-hero__index a:focus-visible {
  color: var(--ky-paper);
  border-left-color: var(--ky-copper-300);
  padding-left: 20px;
}

.page-about .about-hero__idx {
  font-family: var(--ky-font-mono);
  font-size: 12px;
  letter-spacing: .14em;
  color: var(--ky-copper-300);
}

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

.page-about .about-hero__figure .ky-figure__media {
  border: 1px solid var(--ab-deep-line);
  background: rgba(20, 24, 26, .35);
}

.page-about .about-hero__figure .ky-figure__caption {
  margin-top: 12px;
  color: rgba(246, 241, 231, .62);
}

/* ---------- 通用章节框架 ---------- */
.page-about .about-section {
  padding-block: var(--ab-gap);
  position: relative;
}

.page-about .about-section--paper {
  background: var(--ky-paper);
  color: var(--ky-ink);
}

.page-about .about-section--karst {
  background: var(--ky-karst-100);
  color: var(--ky-ink);
}

.page-about .about-section--karst::before,
.page-about .about-section--paper::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 14px;
  background:
    linear-gradient(135deg, transparent 50%, var(--ky-copper-600) 50%) 0 0 / 22px 14px repeat-x;
  opacity: .35;
  pointer-events: none;
}

.page-about .about-head {
  max-width: 26em;
  margin-bottom: clamp(28px, 4vw, 48px);
}

.page-about .ky-index {
  margin: 0 0 14px;
  font-family: var(--ky-font-mono);
  font-size: 12px;
  letter-spacing: .18em;
  color: var(--ky-copper-600);
}

.page-about .about-h2 {
  margin: 0;
  font-family: var(--ky-font-display);
  font-weight: 300;
  font-size: clamp(26px, 4.2vw, 42px);
  line-height: 1.24;
  letter-spacing: -.01em;
  color: var(--ky-karst-800);
}

/* ---------- 01 定位 ---------- */
.page-about .about-position {
  display: grid;
  gap: 22px;
  max-width: 62ch;
}

.page-about .about-position .ky-text {
  margin: 0;
}

.page-about .about-position__aside {
  margin-top: 30px;
  padding: 18px 20px;
  border-left: 3px solid var(--ky-copper-600);
  background: var(--ky-paper-raised);
  max-width: 52ch;
}

.page-about .about-position__aside .ky-text {
  margin: 0;
}

.page-about .about-position a,
.page-about .about-channels a,
.page-about .about-principles a {
  color: var(--ky-karst-800);
  text-decoration: underline;
  text-decoration-color: var(--ky-neon-cyan);
  text-decoration-thickness: 2px;
  text-underline-offset: 3px;
}

.page-about .about-position a:hover,
.page-about .about-channels a:hover,
.page-about .about-principles a:hover {
  color: var(--ky-copper-600);
}

/* ---------- 02 四条通道 ---------- */
.page-about .about-channels {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--ab-paper-line);
  border-block: 1px solid var(--ab-paper-line);
}

.page-about .about-channel {
  background: var(--ky-karst-100);
  padding: clamp(24px, 3.4vw, 38px) clamp(18px, 3vw, 32px);
  display: grid;
  gap: 10px;
  transition: background 220ms var(--ky-ease), transform 220ms var(--ky-ease);
}

.page-about .about-channel:hover {
  background: var(--ky-paper-raised);
}

.page-about .about-channel__no {
  font-family: var(--ky-font-mono);
  font-size: 12px;
  letter-spacing: .22em;
  color: var(--ky-copper-600);
}

.page-about .about-channel__title {
  margin: 0;
  font-family: var(--ky-font-display);
  font-weight: 400;
  font-size: clamp(19px, 2.3vw, 24px);
  letter-spacing: .01em;
  color: var(--ky-karst-800);
}

.page-about .about-channel .ky-text {
  margin: 0;
  max-width: 58ch;
}

.page-about .about-channels__note {
  margin: 32px 0 0;
  padding-left: 18px;
  border-left: 2px dashed var(--ky-copper-600);
  color: var(--ky-karst-400);
  max-width: 54ch;
}

/* ---------- 03 历程 ---------- */
.page-about .about-history {
  display: grid;
  gap: clamp(32px, 5vw, 48px);
}

.page-about .about-timeline {
  list-style: none;
  margin: 0;
  padding: 0 0 0 34px;
  position: relative;
}

.page-about .about-timeline::before {
  content: "";
  position: absolute;
  left: 10px;
  top: 10px;
  bottom: 10px;
  width: 1px;
  background: linear-gradient(to bottom,
    var(--ky-copper-600) 0%,
    var(--ky-copper-600) 62%,
    rgba(169, 102, 43, .18) 100%);
}

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

.page-about .about-stage + .about-stage {
  margin-top: 6px;
}

.page-about .about-stage__box {
  border-bottom: 1px solid var(--ab-paper-line);
}

.page-about .about-stage:last-child .about-stage__box {
  border-bottom: 0;
}

.page-about .about-stage__sum {
  display: flex;
  align-items: baseline;
  gap: 14px;
  padding: 16px 0;
  cursor: pointer;
  list-style: none;
  position: relative;
}

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

.page-about .about-stage__sum:focus-visible {
  outline: 2px solid var(--ky-neon-cyan);
  outline-offset: 3px;
}

.page-about .about-stage__node {
  position: absolute;
  left: -30px;
  top: 24px;
  width: 13px;
  height: 13px;
  border-radius: 50%;
  background: var(--ky-paper);
  border: 2px solid var(--ky-copper-600);
  transition: background 200ms var(--ky-ease), border-color 200ms var(--ky-ease);
}

.page-about .about-stage__box[open] .about-stage__node {
  background: var(--ky-copper-600);
  border-color: var(--ky-copper-300);
}

.page-about .about-stage__num {
  font-family: var(--ky-font-mono);
  font-weight: 700;
  font-size: clamp(24px, 3.6vw, 34px);
  letter-spacing: -.02em;
  color: var(--ky-copper-600);
  min-width: 2.2em;
}

.page-about .about-stage__meta {
  display: flex;
  flex-direction: column;
  gap: 3px;
  flex: 1 1 auto;
}

.page-about .about-stage__years {
  font-family: var(--ky-font-mono);
  font-size: 12px;
  letter-spacing: .14em;
  color: var(--ky-karst-400);
}

.page-about .about-stage__name {
  font-family: var(--ky-font-display);
  font-weight: 400;
  font-size: clamp(17px, 2.1vw, 21px);
  color: var(--ky-karst-800);
}

.page-about .about-stage__toggle {
  position: relative;
  width: 18px;
  height: 18px;
  flex: 0 0 auto;
  align-self: center;
}

.page-about .about-stage__toggle::before,
.page-about .about-stage__toggle::after {
  content: "";
  position: absolute;
  top: 50%;
  left: 0;
  width: 18px;
  height: 1px;
  background: var(--ky-copper-600);
  transition: transform 200ms var(--ky-ease), opacity 200ms var(--ky-ease);
}

.page-about .about-stage__toggle::after {
  transform: rotate(90deg);
}

.page-about .about-stage__box[open] .about-stage__toggle::after {
  transform: rotate(0deg);
  opacity: 0;
}

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

.page-about .about-stage__body p {
  margin: 0;
  max-width: 58ch;
  line-height: 1.85;
  color: var(--ky-ink);
}

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

.page-about .about-history__figure .ky-figure__media {
  border: 1px solid var(--ab-paper-line);
  background: var(--ky-karst-100);
}

.page-about .about-history__figure .ky-figure__caption {
  margin-top: 12px;
  color: var(--ky-karst-400);
}

/* ---------- 04 团队 ---------- */
.page-about .about-section--deep {
  background: var(--ky-karst-800);
  color: rgba(246, 241, 231, .86);
  position: relative;
  overflow: hidden;
}

.page-about .about-section--deep::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(115deg, transparent 46%, rgba(224, 172, 99, .10) 47%, transparent 48%),
    linear-gradient(65deg, transparent 62%, rgba(224, 172, 99, .07) 63%, transparent 64%);
  background-size: 180px 140px, 240px 160px;
  pointer-events: none;
}

.page-about .about-team {
  position: relative;
  display: grid;
  gap: clamp(32px, 5vw, 52px);
}

.page-about .about-index--deep {
  color: var(--ky-copper-300);
}

.page-about .about-h2--deep {
  color: var(--ky-paper);
}

.page-about .about-team__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: clamp(20px, 3vw, 28px);
}

.page-about .about-team__item {
  padding-left: 20px;
  border-left: 2px solid var(--ab-deep-line);
  transition: border-color 200ms var(--ky-ease);
}

.page-about .about-team__item:hover {
  border-left-color: var(--ky-copper-300);
}

.page-about .about-team__name {
  margin: 0 0 8px;
  font-family: var(--ky-font-sans);
  font-weight: 500;
  font-size: 16px;
  letter-spacing: .06em;
  color: var(--ky-copper-300);
}

.page-about .about-team__item p {
  margin: 0;
  max-width: 54ch;
  line-height: 1.85;
  color: rgba(246, 241, 231, .82);
}

.page-about .about-team__daily {
  margin: 30px 0 0;
  max-width: 58ch;
  color: rgba(246, 241, 231, .78);
}

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

.page-about .about-team__figure .ky-figure__media {
  border: 1px solid var(--ab-deep-line);
  background: rgba(20, 24, 26, .35);
}

.page-about .about-team__figure .ky-figure__caption {
  margin-top: 12px;
  color: rgba(246, 241, 231, .6);
}

/* ---------- 05 覆盖 ---------- */
.page-about .about-reach {
  display: grid;
  gap: clamp(30px, 4vw, 44px);
}

.page-about .about-reach__figures {
  display: grid;
  gap: 26px;
}

.page-about .about-figure {
  padding-left: 16px;
  border-left: 2px solid var(--ky-copper-600);
}

.page-about .about-figure__num {
  margin: 0;
  font-family: var(--ky-font-mono);
  font-weight: 700;
  font-size: clamp(34px, 6vw, 54px);
  line-height: 1;
  letter-spacing: -.03em;
  color: var(--ky-copper-600);
}

.page-about .about-figure__unit {
  font-size: .44em;
  margin-left: 4px;
  color: var(--ky-karst-400);
  letter-spacing: 0;
}

.page-about .about-figure__label {
  margin: 8px 0 0;
  font-size: 13px;
  letter-spacing: .08em;
  color: var(--ky-karst-400);
}

.page-about .about-reach__ridge {
  display: grid;
  gap: 18px;
}

.page-about .about-ridge {
  width: 100%;
  height: auto;
  max-width: 420px;
}

.page-about .about-reach__note {
  margin: 0;
  max-width: 56ch;
  color: var(--ky-karst-800);
}

/* ---------- 06 原则 ---------- */
.page-about .about-principles {
  display: grid;
  gap: clamp(20px, 3vw, 30px);
}

.page-about .about-principle {
  position: relative;
  background: var(--ky-paper-raised);
  border: 1px solid var(--ky-copper-600);
  padding: clamp(22px, 3vw, 32px);
  transition: border-color 200ms var(--ky-ease), transform 200ms var(--ky-ease);
}

.page-about .about-principle:hover {
  transform: translateY(-2px);
  border-color: var(--ky-copper-300);
}

.page-about .about-principle__mark {
  position: absolute;
  top: -1px;
  right: -1px;
  width: 22px;
  height: 22px;
  background:
    linear-gradient(135deg, transparent 48%, var(--ky-copper-600) 49%, var(--ky-copper-600) 51%, transparent 52%);
  opacity: .8;
}

.page-about .about-principle__title {
  margin: 0 0 12px;
  font-family: var(--ky-font-display);
  font-weight: 400;
  font-size: clamp(19px, 2.4vw, 24px);
  color: var(--ky-karst-800);
}

.page-about .about-principle .ky-text {
  margin: 0;
  max-width: 52ch;
}

.page-about .about-principles__note {
  margin: 30px 0 0;
  max-width: 56ch;
  color: var(--ky-karst-400);
}

.page-about .about-actions {
  margin-top: 34px;
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
}

.page-about .about-actions .ky-btn {
  text-decoration: none;
}

/* ---------- 收尾 ---------- */
.page-about .about-coda {
  background: var(--ky-copper-900);
  color: rgba(246, 241, 231, .8);
  padding-block: clamp(30px, 4vw, 46px);
}

.page-about .about-coda__inner {
  display: grid;
  gap: 24px;
  align-items: center;
}

.page-about .about-coda__region {
  margin: 0 0 10px;
  font-family: var(--ky-font-mono);
  font-size: 12px;
  letter-spacing: .2em;
  color: var(--ky-copper-300);
}

.page-about .about-coda__line {
  margin: 4px 0 0;
  font-size: 14px;
  line-height: 1.7;
}

.page-about .about-back {
  justify-self: start;
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 11px 20px;
  border: 1px solid var(--ky-copper-300);
  color: var(--ky-copper-300);
  font-size: 14px;
  letter-spacing: .08em;
  text-decoration: none;
  transition: background 200ms var(--ky-ease), color 200ms var(--ky-ease);
}

.page-about .about-back::before {
  content: "\2190";
  font-family: var(--ky-font-mono);
}

.page-about .about-back:hover,
.page-about .about-back:focus-visible {
  background: var(--ky-copper-300);
  color: var(--ky-copper-900);
}

/* ---------- 响应式 ---------- */
@media (min-width: 720px) {
  .page-about .about-hero__index {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    column-gap: 26px;
  }

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

  .page-about .about-team__list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 28px 32px;
  }

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

  .page-about .about-reach__figures {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 20px;
  }

  .page-about .about-coda__inner {
    grid-template-columns: minmax(0, 1fr) auto;
  }

  .page-about .about-back {
    justify-self: end;
  }
}

@media (min-width: 960px) {
  .page-about .about-hero__inner {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, .95fr);
    align-items: center;
  }

  .page-about .about-timeline {
    padding-left: 56px;
  }

  .page-about .about-timeline::before {
    left: 14px;
  }

  .page-about .about-stage__node {
    left: -46px;
  }

  .page-about .about-history {
    grid-template-columns: minmax(0, 1.15fr) minmax(0, .85fr);
    align-items: start;
  }

  .page-about .about-history__figure {
    position: sticky;
    top: 40px;
  }

  .page-about .about-team {
    grid-template-columns: minmax(0, 1.2fr) minmax(0, .8fr);
    align-items: start;
  }

  .page-about .about-team__figure {
    position: sticky;
    top: 40px;
  }

  .page-about .about-reach {
    grid-template-columns: minmax(0, 1fr) minmax(0, .9fr);
    align-items: center;
  }

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

@media (min-width: 1180px) {
  .page-about .about-channel {
    grid-template-columns: 4em minmax(0, 14em) minmax(0, 1fr);
    align-items: baseline;
    column-gap: 24px;
  }

  .page-about .about-channel__no {
    grid-column: 1;
    align-self: baseline;
  }

  .page-about .about-channel__title {
    grid-column: 2;
  }

  .page-about .about-channel .ky-text {
    grid-column: 3;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-principle:hover {
    transform: none;
  }

  .page-about .about-hero__index a:hover,
  .page-about .about-hero__index a:focus-visible {
    padding-left: 14px;
  }
}
<<<END>>>