.page-about {
  --about-rail: 216px;
  --about-gap: 40px;
  --about-pad: clamp(18px, 4vw, 30px);
  --about-line: rgba(169, 178, 166, .28);
  --about-body: rgba(242, 239, 230, .8);
  display: block;
  padding: calc(var(--header-h) + 22px) 0 90px;
  color: var(--paper);
  background:
    radial-gradient(900px 480px at 8% 0%, rgba(51, 225, 208, .10), transparent 60%),
    radial-gradient(760px 520px at 92% 24%, rgba(185, 138, 46, .12), transparent 58%),
    var(--green-deep);
}

.page-about *,
.page-about *::before,
.page-about *::after {
  box-sizing: border-box;
}

/* ——— 面包屑 ——— */
.page-about .breadcrumb {
  margin-bottom: 16px;
}

.page-about .breadcrumb__list {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 0;
  padding: 0;
  list-style: none;
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--scan);
}

.page-about .breadcrumb__item + .breadcrumb__item::before {
  content: "/";
  margin-right: 8px;
  color: rgba(169, 178, 166, .5);
}

.page-about .breadcrumb__link {
  color: var(--paper-dim);
  text-decoration: none;
  border-bottom: 1px solid rgba(169, 178, 166, .35);
}

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

.page-about .breadcrumb__link:focus-visible {
  outline: 2px solid var(--neon);
  outline-offset: 2px;
}

/* ——— 首屏 ——— */
.page-about .about-hero {
  position: relative;
  isolation: isolate;
  overflow: hidden;
  padding: 6px 0 46px;
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  background: repeating-linear-gradient(180deg, rgba(169, 178, 166, .06) 0 1px, transparent 1px 5px);
  mask-image: linear-gradient(180deg, #000 42%, transparent 100%);
  -webkit-mask-image: linear-gradient(180deg, #000 42%, transparent 100%);
}

.page-about .about-hero__kicker {
  margin: 0 0 12px;
  color: var(--gold-lt);
}

.page-about .about-hero__title {
  max-width: 16ch;
  margin: 0 0 20px;
  font-size: clamp(30px, 6.6vw, 56px);
  font-weight: 900;
  line-height: 1.1;
  letter-spacing: -.015em;
  color: var(--paper);
  text-shadow: 2px 2px 0 rgba(185, 138, 46, .95), -1px -1px 0 rgba(51, 225, 208, .26);
}

.page-about .about-hero__lede {
  max-width: 42em;
  margin: 0;
  font-size: 17px;
  line-height: 1.78;
  color: rgba(242, 239, 230, .9);
}

.page-about .about-hero__stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: 30px 0 0;
  padding: 0;
  background: var(--about-line);
  border: 1px solid var(--about-line);
  border-radius: var(--radius);
  overflow: hidden;
}

.page-about .about-hero__stat {
  margin: 0;
  padding: 14px 16px;
  background: rgba(20, 24, 26, .5);
}

.page-about .about-hero__stat dt {
  margin: 0 0 6px;
  font-size: 12px;
  letter-spacing: .12em;
  color: var(--scan);
}

.page-about .about-hero__stat dd {
  margin: 0;
  font-size: 20px;
  font-weight: 700;
  letter-spacing: .02em;
  color: var(--gold-lt);
}

/* ——— 两栏骨架 ——— */
.page-about .about-shell {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 30px;
  align-items: start;
}

.page-about .about-toc {
  min-width: 0;
}

.page-about .about-toc__title {
  margin: 0 0 10px;
  color: var(--gold);
}

.page-about .about-toc__list {
  display: flex;
  gap: 8px;
  margin: 0;
  padding: 0 0 8px;
  list-style: none;
  overflow-x: auto;
  scrollbar-width: thin;
}

.page-about .about-toc__link {
  display: block;
  padding: 8px 14px;
  border: 1px solid rgba(169, 178, 166, .34);
  border-radius: var(--radius-pill);
  font-family: var(--font-mono);
  font-size: 13px;
  line-height: 1.2;
  white-space: nowrap;
  color: var(--paper-dim);
  text-decoration: none;
  transition: color .2s ease, border-color .2s ease, background-color .2s ease;
}

.page-about .about-toc__link:hover,
.page-about .about-toc__link:focus-visible {
  color: var(--neon);
  border-color: var(--neon);
  background: rgba(51, 225, 208, .09);
}

.page-about .about-toc__link:focus-visible {
  outline: 2px solid var(--neon);
  outline-offset: 2px;
}

.page-about .about-flow {
  display: flex;
  flex-direction: column;
  gap: 54px;
  min-width: 0;
}

/* ——— 区块 ——— */
.page-about .about-block {
  min-width: 0;
  scroll-margin-top: calc(var(--header-h) + 28px);
}

.page-about .about-block__head {
  display: flex;
  flex-direction: column;
  gap: 10px;
  margin-bottom: 22px;
}

.page-about .about-block__idx {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: .1em;
  color: var(--gold-lt);
}

.page-about .about-block__title {
  margin: 0;
  font-size: clamp(22px, 3.4vw, 32px);
  font-weight: 800;
  line-height: 1.26;
  letter-spacing: -.005em;
  color: var(--paper);
}

.page-about .about-block__note {
  max-width: 42em;
  margin: 0;
  font-size: 17px;
  line-height: 1.78;
  color: var(--about-body);
}

.page-about .about-block--paper {
  padding: var(--about-pad);
  background: var(--paper);
  color: var(--ink);
  border: var(--border-print);
  border-radius: var(--radius);
  box-shadow: var(--shadow-layer);
}

.page-about .about-block--paper .about-block__idx {
  color: var(--gold);
}

.page-about .about-block--paper .about-block__title {
  color: var(--ink);
}

.page-about .about-block--paper .about-block__note {
  color: var(--ink-soft);
}

/* ——— 图片 ——— */
.page-about .about-figure {
  margin: 0 0 26px;
}

.page-about .about-figure--last {
  margin: 28px 0 0;
}

.page-about .about-figure img,
.page-about .about-number__figure img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  object-fit: cover;
}

/* ——— 条目样例 ——— */
.page-about .about-spec {
  padding: 20px 20px 18px;
  background: var(--paper);
  color: var(--ink);
  border: var(--border-print);
  border-radius: var(--radius);
  box-shadow: var(--shadow-layer);
}

.page-about .about-spec__label {
  margin: 0 0 12px;
  color: var(--gold);
}

.page-about .about-spec__row {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px 14px;
  padding-bottom: 14px;
  border-bottom: 1px dashed rgba(20, 24, 26, .25);
}

.page-about .about-spec__no {
  display: inline-block;
  padding: 4px 12px;
  font-size: 17px;
  font-weight: 700;
  letter-spacing: .04em;
  color: var(--ink);
  background: var(--gold-lt);
  border: 1px solid var(--gold);
  border-radius: 4px;
  box-shadow: 2px 2px 0 rgba(20, 24, 26, .2);
}

.page-about .about-spec__name {
  font-size: 17px;
  font-weight: 600;
  color: var(--ink);
}

.page-about .about-spec__meta {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 12px;
  margin: 16px 0 0;
}

.page-about .about-spec__cell dt {
  margin: 0 0 5px;
  font-size: 12px;
  letter-spacing: .12em;
  color: var(--ink-soft);
}

.page-about .about-spec__cell dd {
  margin: 0;
  font-size: 15px;
  font-weight: 600;
  letter-spacing: .02em;
  color: var(--ink);
}

.page-about .about-spec__foot {
  margin: 16px 0 0;
  font-size: 15px;
  line-height: 1.7;
  color: var(--ink-soft);
}

/* ——— 时间线 ——— */
.page-about .about-years {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 0 0 26px;
}

.page-about .about-years__chip {
  padding: 6px 14px;
  font-size: 14px;
  color: var(--gold-lt);
  text-decoration: none;
  border: 1px solid rgba(230, 198, 122, .45);
  border-radius: var(--radius-pill);
  transition: background-color .2s ease, color .2s ease, border-color .2s ease;
}

.page-about .about-years__chip:hover,
.page-about .about-years__chip:focus-visible {
  color: var(--green-deep);
  background: var(--gold-lt);
  border-color: var(--gold-lt);
}

.page-about .about-years__chip:focus-visible {
  outline: 2px solid var(--neon);
  outline-offset: 2px;
}

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

.page-about .about-timeline::before {
  content: "";
  position: absolute;
  left: 7px;
  top: 10px;
  bottom: 18px;
  width: 2px;
  background: linear-gradient(180deg, var(--gold) 0%, rgba(51, 225, 208, .55) 58%, rgba(169, 178, 166, .16) 100%);
}

.page-about .about-timeline__item {
  position: relative;
  padding: 0 0 28px 36px;
  scroll-margin-top: calc(var(--header-h) + 30px);
}

.page-about .about-timeline__item:last-child {
  padding-bottom: 4px;
}

.page-about .about-timeline__item::before {
  content: "";
  position: absolute;
  left: 0;
  top: 6px;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: var(--green-deep);
  border: 2px solid var(--gold);
  box-shadow: 0 0 0 4px rgba(185, 138, 46, .14);
}

.page-about .about-timeline__year {
  margin: 0 0 4px;
  font-family: var(--font-mono);
  font-size: 20px;
  font-weight: 700;
  letter-spacing: .04em;
  color: var(--gold-lt);
}

.page-about .about-timeline__title {
  margin: 0 0 6px;
  font-size: 18px;
  font-weight: 700;
  line-height: 1.4;
  color: var(--paper);
}

.page-about .about-timeline__text {
  max-width: 40em;
  margin: 0;
  font-size: 16px;
  line-height: 1.78;
  color: var(--about-body);
}

/* ——— 四道工序 ——— */
.page-about .about-steps {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(min(208px, 100%), 1fr));
  gap: 14px;
}

.page-about .about-step {
  position: relative;
  background: var(--paper);
  color: var(--ink);
  border: var(--border-print);
  border-radius: var(--radius);
  box-shadow: 5px 5px 0 rgba(185, 138, 46, .55);
}

.page-about .about-step__head {
  position: relative;
  display: block;
  padding: 16px 44px 14px 16px;
  cursor: pointer;
  list-style: none;
}

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

.page-about .about-step__head::after {
  content: "";
  position: absolute;
  top: 22px;
  right: 20px;
  width: 9px;
  height: 9px;
  border-right: 2px solid var(--gold);
  border-bottom: 2px solid var(--gold);
  transform: rotate(45deg);
  transition: transform .25s ease;
}

.page-about .about-step[open] .about-step__head::after {
  transform: rotate(-135deg);
}

.page-about .about-step__head:focus-visible {
  outline: 2px solid var(--neon);
  outline-offset: -2px;
}

.page-about .about-step__no {
  display: block;
  margin-bottom: 6px;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: .12em;
  color: var(--gold);
}

.page-about .about-step__name {
  display: block;
  font-size: 18px;
  font-weight: 700;
  line-height: 1.35;
  color: var(--ink);
}

.page-about .about-step__body {
  padding: 14px 16px 18px;
  border-top: 1px dashed rgba(20, 24, 26, .22);
}

.page-about .about-step__body p {
  margin: 0 0 10px;
  font-size: 15px;
  line-height: 1.72;
  color: var(--ink-soft);
}

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

.page-about .about-step__deliver {
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: .02em;
  color: var(--gold);
}

/* ——— 编号规则 ——— */
.page-about .about-number {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 24px;
  align-items: start;
}

.page-about .about-number__left {
  min-width: 0;
}

.page-about .about-number__parts {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 0 0 20px;
  padding: 0;
  list-style: none;
}

.page-about .about-number__part {
  display: flex;
  flex-direction: column;
  gap: 3px;
  min-width: 96px;
  padding: 10px 14px;
  background: var(--paper-2);
  border: 1px solid rgba(20, 24, 26, .2);
  border-radius: 4px;
}

.page-about .about-number__key {
  font-size: 16px;
  font-weight: 700;
  color: var(--ink);
}

.page-about .about-number__label {
  font-size: 12px;
  letter-spacing: .04em;
  color: var(--ink-soft);
}

.page-about .tablist {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-bottom: 18px;
  border-bottom: 2px solid rgba(20, 24, 26, .15);
}

.page-about .tab {
  appearance: none;
  margin-bottom: -2px;
  padding: 9px 14px;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: .04em;
  color: var(--ink-soft);
  background: transparent;
  border: 0;
  border-bottom: 3px solid transparent;
  border-radius: 4px 4px 0 0;
  cursor: pointer;
  transition: color .2s ease, background-color .2s ease, border-color .2s ease;
}

.page-about .tab:hover {
  color: var(--ink);
}

.page-about .tab[aria-selected="true"] {
  color: var(--ink);
  background: rgba(51, 225, 208, .14);
  border-bottom-color: var(--neon);
}

.page-about .tab:focus-visible {
  outline: 2px solid var(--neon);
  outline-offset: 2px;
}

.page-about .tabpanel {
  outline: none;
}

.page-about .tabpanel[hidden] {
  display: none;
}

.page-about .tabpanel:focus-visible {
  outline: 2px solid var(--neon);
  outline-offset: 4px;
}

.page-about .about-number__code {
  display: inline-block;
  margin: 0 0 12px;
  padding: 6px 14px;
  font-size: 16px;
  font-weight: 700;
  letter-spacing: .06em;
  color: var(--neon);
  background: var(--green-deep);
  border-radius: 4px;
  box-shadow: 3px 3px 0 rgba(20, 24, 26, .25);
}

.page-about .about-number__desc {
  margin: 0;
  font-size: 16px;
  line-height: 1.75;
  color: var(--ink-soft);
}

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

/* ——— 社区互认 ——— */
.page-about .about-community {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 12px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .about-community__item {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 12px;
  align-items: start;
  padding: 14px 16px;
  background: rgba(242, 239, 230, .045);
  border: 1px solid var(--about-line);
  border-left: 3px solid var(--gold);
  border-radius: 0 var(--radius) var(--radius) 0;
}

.page-about .about-community__no {
  padding-top: 2px;
  font-size: 13px;
  font-weight: 700;
  color: var(--gold-lt);
}

.page-about .about-community__item p {
  margin: 0;
  font-size: 15px;
  line-height: 1.72;
  color: var(--about-body);
}

/* ——— 团队与节奏 ——— */
.page-about .about-roster {
  display: flex;
  flex-direction: column;
  border-top: 2px solid var(--ink);
}

.page-about .about-roster__row {
  display: grid;
  grid-template-columns: 44px minmax(0, 1fr);
  gap: 4px 14px;
  align-items: baseline;
  padding: 14px 4px;
  border-bottom: 1px dashed rgba(20, 24, 26, .24);
}

.page-about .about-roster__num {
  font-size: 22px;
  font-weight: 700;
  letter-spacing: .02em;
  color: var(--gold);
}

.page-about .about-roster__role {
  font-size: 17px;
  font-weight: 700;
  color: var(--ink);
}

.page-about .about-roster__desc {
  grid-column: 2;
  font-size: 15px;
  line-height: 1.7;
  color: var(--ink-soft);
}

.page-about .about-team__scale {
  margin: 22px 0 0;
  padding: 12px 16px;
  font-size: 15px;
  line-height: 1.72;
  color: var(--ink-soft);
  background: rgba(51, 225, 208, .1);
  border-left: 3px solid var(--neon);
  border-radius: 0 4px 4px 0;
}

.page-about .about-cadence {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 14px;
  margin-top: 26px;
}

.page-about .about-cadence__card {
  padding: 18px;
  color: var(--paper);
  background: var(--green-deep);
  border: 2px solid var(--ink);
  border-radius: var(--radius);
  box-shadow: 5px 5px 0 rgba(20, 24, 26, .22);
}

.page-about .about-cadence__card .label {
  display: block;
  margin-bottom: 8px;
  color: var(--neon);
}

.page-about .about-cadence__title {
  margin: 0 0 8px;
  font-size: 19px;
  font-weight: 800;
  color: var(--gold-lt);
}

.page-about .about-cadence__text {
  margin: 0;
  font-size: 15px;
  line-height: 1.72;
  color: rgba(242, 239, 230, .82);
}

/* ——— 结尾 ——— */
.page-about .about-outro {
  margin-top: 60px;
  padding: var(--about-pad);
  border: 2px solid rgba(51, 225, 208, .45);
  border-radius: var(--radius);
  box-shadow: var(--shadow-soft);
  background:
    linear-gradient(135deg, rgba(51, 225, 208, .16), rgba(185, 138, 46, .16) 62%, rgba(20, 24, 26, .22)),
    rgba(20, 24, 26, .5);
}

.page-about .about-outro__kicker {
  margin: 0 0 10px;
  color: var(--neon);
}

.page-about .about-outro__title {
  margin: 0 0 12px;
  font-size: clamp(21px, 3vw, 28px);
  font-weight: 800;
  line-height: 1.3;
  color: var(--paper);
}

.page-about .about-outro__text {
  max-width: 40em;
  margin: 0 0 22px;
  font-size: 16px;
  line-height: 1.75;
  color: rgba(242, 239, 230, .84);
}

.page-about .about-outro__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

/* ——— 断点 ——— */
@media (min-width: 620px) {
  .page-about .about-spec__meta {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

@media (min-width: 680px) {
  .page-about .about-hero__stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

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

@media (min-width: 760px) {
  .page-about .about-community {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 14px;
  }

  .page-about .about-roster__row {
    grid-template-columns: 56px 168px minmax(0, 1fr);
    gap: 0 18px;
  }

  .page-about .about-roster__desc {
    grid-column: auto;
  }
}

@media (min-width: 900px) {
  .page-about .about-number {
    grid-template-columns: 5fr 6fr;
    gap: 30px;
  }
}

@media (min-width: 1060px) {
  .page-about .about-shell {
    grid-template-columns: var(--about-rail) minmax(0, 1fr);
    gap: var(--about-gap);
  }

  .page-about .about-toc {
    position: sticky;
    top: calc(var(--header-h) + 20px);
  }

  .page-about .about-toc__list {
    flex-direction: column;
    gap: 2px;
    overflow: visible;
    padding-bottom: 0;
    border-left: 2px solid var(--about-line);
  }

  .page-about .about-toc__link {
    margin-left: -2px;
    padding: 8px 14px;
    white-space: normal;
    border: 0;
    border-left: 2px solid transparent;
    border-radius: 0;
  }

  .page-about .about-toc__link:hover,
  .page-about .about-toc__link:focus-visible {
    border-left-color: var(--neon);
    background: rgba(51, 225, 208, .08);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-step__head::after,
  .page-about .about-toc__link,
  .page-about .tab,
  .page-about .about-years__chip {
    transition: none;
  }

  .page-about .about-hero::after {
    display: none;
  }
}