.page-about {
  --about-radius-lg: 14px;
  --about-radius-sm: 4px;
  --about-offset: 32px;
}

/* ============ 首屏 ============ */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  padding-top: clamp(96px, 13vw, 152px);
  padding-bottom: clamp(48px, 7vw, 84px);
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(to right, rgba(53, 224, 214, 0.07) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(53, 224, 214, 0.05) 1px, transparent 1px);
  background-size: 120px 120px;
  pointer-events: none;
}

.page-about .about-hero > .container {
  position: relative;
  z-index: 1;
}

.page-about .about-hero__title {
  display: flex;
  flex-direction: column;
  margin: 14px 0 0;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(38px, 7.2vw, 96px);
  line-height: 0.98;
  letter-spacing: -0.02em;
  color: var(--white);
}

.page-about .about-hero__line {
  display: block;
  overflow-wrap: break-word;
}

.page-about .about-hero__line + .about-hero__line {
  color: var(--text-on-dark);
  opacity: 0.92;
}

.page-about .about-hero__lede {
  margin: clamp(22px, 3.5vw, 34px) 0 0;
  max-width: 46ch;
  color: var(--text-on-dark);
}

/* 首屏导读索引 */
.page-about .about-index {
  display: grid;
  grid-template-columns: 1fr;
  gap: 4px 24px;
  margin-top: clamp(32px, 5vw, 54px);
  padding-top: 20px;
  border-top: 1px solid var(--ink-500);
}

.page-about .about-index__item {
  display: flex;
  align-items: center;
  gap: 12px;
  min-height: 44px;
  padding: 6px 0;
  color: var(--muted-on-dark);
  text-decoration: none;
  font-size: var(--step-sm);
  border-bottom: 1px solid rgba(31, 61, 87, 0.55);
  transition: color var(--dur) var(--ease);
}

.page-about .about-index__num {
  color: var(--amber-400);
  font-size: 11px;
  flex: 0 0 auto;
}

.page-about .about-index__item:hover,
.page-about .about-index__item:focus-visible {
  color: var(--cyan-200);
}

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

/* ============ 通用区块 ============ */
.page-about .about-band {
  padding-block: clamp(56px, 8vw, 104px);
}

.page-about .about-head {
  margin-bottom: clamp(26px, 4vw, 46px);
}

.page-about .about-eyebrow--ink {
  color: var(--cyan-ink);
}

.page-about .about-head__title {
  margin: 10px 0 0;
  max-width: 24ch;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(25px, 3.6vw, 42px);
  line-height: 1.16;
  letter-spacing: -0.015em;
  color: var(--white);
}

.page-about .about-intro .about-head__title,
.page-about .about-upgrade .about-head__title,
.page-about .about-channel .about-head__title,
.page-about .about-city .about-head__title {
  color: var(--text-on-paper);
}

.page-about .about-copy {
  margin: 0 0 18px;
  max-width: 38ch;
  font-size: var(--step-md);
  line-height: 1.78;
  color: var(--text-on-paper);
}

.page-about .about-copy--wide {
  max-width: 44ch;
}

.page-about .about-copy--dark {
  color: var(--text-on-dark);
}

.page-about .about-inline-link {
  display: inline-block;
  padding-bottom: 2px;
  border-bottom: 1px solid currentColor;
  color: var(--cyan-ink);
  text-decoration: none;
  font-weight: 500;
  transition: color var(--dur) var(--ease);
}

.page-about .about-inline-link--ink {
  color: var(--ink-700);
  margin-top: 4px;
}

.page-about .about-inline-link:hover,
.page-about .about-inline-link:focus-visible {
  color: var(--amber-400);
}

.page-about .about-caption {
  display: block;
  margin-top: 10px;
  font-size: 11px;
  letter-spacing: 0.08em;
  color: var(--mist-300);
}

/* ============ 品牌自述 ============ */
.page-about .about-intro__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 32px;
}

.page-about .about-intro__figure {
  position: relative;
  margin: 0;
  overflow: hidden;
  border: 1px solid var(--paper-300);
  border-radius: var(--about-radius-lg) var(--about-radius-sm) var(--about-radius-lg) var(--about-radius-sm);
  background: var(--ink-700);
}

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

.page-about .about-intro__stamp {
  position: absolute;
  right: 14px;
  bottom: 14px;
}

.page-about .about-note {
  margin-top: 26px;
  padding-left: 18px;
  border-left: 1px solid var(--paper-300);
}

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

.page-about .about-note__row {
  display: grid;
  grid-template-columns: 5.5em 1fr;
  gap: 12px;
  padding: 8px 0;
  border-bottom: 1px dashed var(--paper-300);
}

.page-about .about-note__row:last-child {
  border-bottom: none;
}

.page-about .about-note__row dt {
  font-size: 11px;
  letter-spacing: 0.08em;
  color: var(--muted-on-paper);
  padding-top: 3px;
}

.page-about .about-note__row dd {
  margin: 0;
  font-size: var(--step-sm);
  line-height: 1.6;
  color: var(--text-on-paper);
}

/* ============ 时间线 ============ */
.page-about .about-timeline__banner {
  margin: 0 0 clamp(28px, 4vw, 46px);
  overflow: hidden;
  border: 1px solid var(--ink-500);
  border-radius: var(--about-radius-sm) var(--about-radius-lg) var(--about-radius-sm) var(--about-radius-lg);
  background: var(--ink-700);
}

.page-about .about-timeline__banner img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 35 / 12;
  object-fit: cover;
}

.page-about .about-timeline__layout {
  display: grid;
  grid-template-columns: 1fr;
  gap: 26px;
}

.page-about .about-scale {
  display: none;
}

.page-about .about-scale__list {
  list-style: none;
  margin: 0;
  padding: 0 0 0 1px;
  border-left: 1px solid var(--ink-500);
  display: flex;
  flex-direction: column;
  gap: 44px;
}

.page-about .about-scale__link {
  position: relative;
  display: block;
  min-height: 44px;
  padding: 4px 0 4px 20px;
  font-family: var(--font-mono);
  font-size: var(--step-xs);
  letter-spacing: 0.08em;
  color: var(--muted-on-dark);
  text-decoration: none;
  transition: color var(--dur) var(--ease);
}

.page-about .about-scale__link::before {
  content: "";
  position: absolute;
  left: -4px;
  top: 9px;
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--ink-500);
  transition: background var(--dur) var(--ease), box-shadow var(--dur) var(--ease);
}

.page-about .about-scale__link:hover,
.page-about .about-scale__link:focus-visible {
  color: var(--cyan-200);
}

.page-about .about-scale__link:hover::before,
.page-about .about-scale__link:focus-visible::before {
  background: var(--amber-400);
  box-shadow: 0 0 0 4px rgba(242, 166, 59, 0.18);
}

.page-about .about-stage {
  position: relative;
  padding: 26px 22px;
  background: var(--ink-700);
  border: 1px solid var(--ink-500);
  border-radius: var(--about-radius-sm) var(--about-radius-lg) var(--about-radius-sm) var(--about-radius-lg);
}

.page-about .about-stage + .about-stage {
  margin-top: 24px;
}

.page-about .about-stage__top {
  display: flex;
  align-items: center;
  gap: 12px;
  flex-wrap: wrap;
  margin-bottom: 12px;
}

.page-about .about-stage__year {
  font-size: var(--step-xl);
  letter-spacing: 0.06em;
  color: var(--amber-400);
}

.page-about .about-stage__title {
  margin: 0 0 16px;
  font-family: var(--font-serif);
  font-weight: 600;
  font-size: clamp(19px, 2.4vw, 24px);
  line-height: 1.45;
  color: var(--white);
}

.page-about .about-stage__line {
  margin: 0 0 14px;
  font-size: var(--step-md);
  line-height: 1.78;
  color: var(--text-on-dark);
  max-width: 46ch;
}

.page-about .about-stage__line:last-child {
  margin-bottom: 0;
}

.page-about .about-stage__label {
  display: block;
  margin-bottom: 4px;
  font-size: 11px;
  letter-spacing: 0.1em;
  color: var(--cyan-400);
}

/* ============ 升级准备 ============ */
.page-about .about-upgrade__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 34px;
}

.page-about .about-upgrade__head .btn {
  margin-top: 6px;
}

.page-about .about-checklist__wrap {
  padding: 24px 20px;
  border: 1px solid var(--paper-300);
  border-radius: var(--about-radius-lg) var(--about-radius-sm) var(--about-radius-lg) var(--about-radius-sm);
  background: rgba(217, 208, 193, 0.24);
}

.page-about .about-checklist__lead {
  margin: 0 0 16px;
  font-size: 11px;
  letter-spacing: 0.1em;
  color: var(--muted-on-paper);
}

.page-about .about-checklist {
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .about-checklist__item {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  min-height: 44px;
  padding: 11px 0;
  border-bottom: 1px dashed var(--paper-300);
}

.page-about .about-checklist__item:last-child {
  border-bottom: none;
}

.page-about .about-checklist__box {
  flex: 0 0 auto;
  width: 20px;
  height: 20px;
  margin: 4px 0 0;
  accent-color: var(--amber-400);
  cursor: pointer;
}

.page-about .about-checklist__box:focus-visible {
  outline: 2px solid var(--amber-400);
  outline-offset: 3px;
}

.page-about .about-checklist__label {
  cursor: pointer;
  font-size: var(--step-md);
  line-height: 1.66;
  color: var(--text-on-paper);
}

.page-about .about-checklist__box:checked + .about-checklist__label .about-checklist__text {
  color: var(--muted-on-paper);
  text-decoration: line-through;
  text-decoration-color: var(--amber-400);
}

.page-about .about-upgrade__foot {
  margin: 20px 0 0;
  font-size: var(--step-sm);
  line-height: 1.7;
  color: var(--muted-on-paper);
}

/* ============ 团队 ============ */
.page-about .about-team__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 32px;
}

.page-about .about-team__figure {
  display: flex;
  align-items: baseline;
  gap: 12px;
  margin: 0 0 14px;
}

.page-about .about-team__num {
  font-size: clamp(56px, 9vw, 88px);
  line-height: 0.9;
  letter-spacing: -0.02em;
  color: var(--amber-400);
}

.page-about .about-team__unit {
  font-size: var(--step-sm);
  color: var(--muted-on-dark);
  letter-spacing: 0.06em;
}

.page-about .about-team__cards {
  display: grid;
  grid-template-columns: 1fr;
  gap: 18px;
}

.page-about .about-team__card {
  padding: 22px 20px;
  background: var(--ink-700);
  border: 1px solid var(--ink-500);
  border-left: 2px solid var(--cyan-400);
  border-radius: var(--about-radius-sm) var(--about-radius-lg) var(--about-radius-sm) var(--about-radius-sm);
}

.page-about .about-team__card-title {
  margin: 0 0 10px;
  font-size: var(--step-xs);
  letter-spacing: 0.08em;
  color: var(--cyan-200);
}

.page-about .about-team__card .about-copy {
  margin-bottom: 0;
  max-width: 40ch;
  font-size: var(--step-sm);
  line-height: 1.75;
}

/* ============ 资质 ============ */
.page-about .about-certs__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 30px;
  align-items: start;
}

.page-about .about-certs__figure {
  margin: 0;
  overflow: hidden;
  border: 1px solid var(--ink-500);
  border-radius: 50% 50% var(--about-radius-lg) var(--about-radius-lg) / 18% 18% var(--about-radius-lg) var(--about-radius-lg);
  background: var(--ink-800);
}

.page-about .about-certs__figure img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
}

.page-about .about-cert-tabs {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.page-about .about-cert-tabs__input {
  position: absolute;
  width: 1px;
  height: 1px;
  opacity: 0;
  pointer-events: none;
}

.page-about .about-cert-tabs__label {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  padding: 8px 16px;
  border: 1px solid var(--ink-500);
  border-radius: 999px;
  font-size: var(--step-sm);
  color: var(--muted-on-dark);
  cursor: pointer;
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease), background var(--dur) var(--ease);
}

.page-about .about-cert-tabs__label:hover {
  border-color: var(--cyan-400);
  color: var(--cyan-200);
}

.page-about .about-cert-tabs__input:checked + .about-cert-tabs__label {
  background: var(--amber-400);
  border-color: var(--amber-400);
  color: var(--ink-900);
  font-weight: 600;
}

.page-about .about-cert-tabs__input:focus-visible + .about-cert-tabs__label {
  outline: 2px solid var(--amber-400);
  outline-offset: 2px;
}

.page-about .about-cert-tabs__panels {
  flex: 0 0 100%;
  margin-top: 20px;
  padding-top: 20px;
  border-top: 1px solid var(--ink-500);
}

.page-about .about-cert-tabs__panel {
  display: none;
}

.page-about .about-cert-tabs__input:nth-of-type(1):checked ~ .about-cert-tabs__panels .about-cert-tabs__panel:nth-child(1),
.page-about .about-cert-tabs__input:nth-of-type(2):checked ~ .about-cert-tabs__panels .about-cert-tabs__panel:nth-child(2),
.page-about .about-cert-tabs__input:nth-of-type(3):checked ~ .about-cert-tabs__panels .about-cert-tabs__panel:nth-child(3) {
  display: block;
}

.page-about .about-cert-tabs__num {
  margin: 0 0 10px;
  font-size: var(--step-sm);
  letter-spacing: 0.08em;
  color: var(--amber-400);
}

.page-about .about-cert-tabs__panel .about-copy {
  margin-bottom: 0;
  max-width: 44ch;
}

/* ============ 渠道 ============ */
.page-about .about-channel__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 22px;
}

.page-about .about-channel__card {
  padding: 24px 22px;
  background: rgba(217, 208, 193, 0.28);
  border: 1px solid var(--paper-300);
  border-radius: var(--about-radius-lg) var(--about-radius-sm) var(--about-radius-lg) var(--about-radius-sm);
}

.page-about .about-channel__num {
  margin: 0 0 10px;
  font-size: var(--step-xs);
  letter-spacing: 0.1em;
  color: var(--cyan-ink);
}

.page-about .about-channel__title {
  margin: 0 0 12px;
  font-family: var(--font-serif);
  font-weight: 600;
  font-size: clamp(18px, 2.2vw, 23px);
  line-height: 1.45;
  color: var(--text-on-paper);
}

.page-about .about-channel__card .about-copy {
  max-width: 42ch;
}

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

/* ============ 郑州 ============ */
.page-about .about-city__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 24px;
}

.page-about .about-city__body {
  position: relative;
  padding-left: 18px;
  border-left: 1px solid var(--paper-300);
}

.page-about .about-city__body .about-copy {
  max-width: 44ch;
}

/* ============ 收尾 ============ */
.page-about .about-close {
  position: relative;
  overflow: hidden;
}

.page-about .about-close::after {
  content: "";
  position: absolute;
  right: -60px;
  bottom: -80px;
  width: 260px;
  height: 260px;
  border-radius: 50%;
  border: 1px solid var(--ink-500);
  pointer-events: none;
}

.page-about .about-close__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 28px;
  align-items: center;
}

.page-about .about-close__title {
  margin: 10px 0 12px;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(26px, 4vw, 46px);
  line-height: 1.14;
  letter-spacing: -0.015em;
  color: var(--white);
}

.page-about .about-close__lede {
  margin: 0;
  max-width: 42ch;
  font-size: var(--step-md);
  line-height: 1.78;
  color: var(--text-on-dark);
}

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

/* ============ 响应式 ============ */
@media (min-width: 600px) {
  .page-about .about-index {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .page-about .about-index__item {
    border-bottom: none;
    border-left: 1px solid var(--ink-500);
    padding-left: 12px;
  }

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

  .page-about .about-checklist__wrap {
    padding: 28px 26px;
  }

  .page-about .about-close__actions {
    gap: 14px;
  }
}

@media (min-width: 900px) {
  .page-about .about-index {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    column-gap: 28px;
  }

  .page-about .about-intro__grid {
    grid-template-columns: 5fr 7fr;
    gap: 48px;
    align-items: start;
  }

  .page-about .about-timeline__layout {
    grid-template-columns: 156px minmax(0, 1fr);
    gap: 56px;
  }

  .page-about .about-scale {
    display: block;
    position: sticky;
    top: calc(var(--bar-h) + 32px);
    align-self: start;
  }

  .page-about .about-upgrade__grid {
    grid-template-columns: 5fr 7fr;
    gap: 48px;
    align-items: start;
  }

  .page-about .about-team__grid {
    grid-template-columns: 5fr 7fr;
    gap: 44px;
    align-items: start;
  }

  .page-about .about-certs__grid {
    grid-template-columns: 5fr 7fr;
    gap: 48px;
    align-items: center;
  }

  .page-about .about-channel__grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 26px;
    align-items: start;
  }

  .page-about .about-city__grid {
    grid-template-columns: 5fr 7fr;
    gap: 48px;
    align-items: start;
  }

  .page-about .about-close__grid {
    grid-template-columns: 7fr 5fr;
    gap: 40px;
  }

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

@media (min-width: 1024px) {
  .page-about .about-stage {
    padding: 30px 28px;
  }

  .page-about .about-stage:nth-child(odd) {
    margin-right: var(--about-offset);
  }

  .page-about .about-stage:nth-child(even) {
    margin-left: var(--about-offset);
  }

  .page-about .about-stage + .about-stage {
    margin-top: var(--about-offset);
  }

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

  .page-about .about-channel__card--offset {
    margin-top: var(--about-offset);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-index__item,
  .page-about .about-scale__link,
  .page-about .about-scale__link::before,
  .page-about .about-cert-tabs__label,
  .page-about .about-inline-link {
    transition: none;
  }
}