.page-about {
  --tl-rail: 13px;
  --tl-gap: 44px;
  --about-hair: var(--line-hair);
}

/* ---------- 本页目录 ---------- */
.page-about .about-index {
  display: flex;
  flex-wrap: wrap;
  margin-top: 18px;
  border-top: 1px solid var(--about-hair);
  border-bottom: 1px solid var(--about-hair);
}

.page-about .about-index a {
  flex: 0 0 auto;
  padding: 10px 14px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .1em;
  color: var(--mist-400);
  text-decoration: none;
  border-right: 1px solid var(--about-hair);
  transition: color var(--ease), background-color var(--ease), box-shadow var(--ease);
}

.page-about .about-index a:last-child {
  border-right: 0;
}

.page-about .about-index a:hover,
.page-about .about-index a:focus-visible {
  color: var(--cyan);
  background: var(--cyan-veil);
  outline: none;
}

.page-about .about-index a[aria-current="true"] {
  color: var(--cyan);
  box-shadow: inset 0 -2px 0 var(--cyan);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero__grid {
  display: grid;
  gap: 26px;
  margin-top: 26px;
}

.page-about .about-hero h1 {
  margin: 14px 0 0;
  font-size: clamp(30px, 6.2vw, 64px);
  line-height: 1.06;
  letter-spacing: -.025em;
  font-weight: 800;
  color: var(--mist-100);
}

.page-about .about-hero__lead {
  position: relative;
  margin: 18px 0 0;
  max-width: 62ch;
  font-size: var(--step-1);
  line-height: 1.72;
  color: var(--mist-100);
}

.page-about .about-hero__lead::before {
  content: "";
  display: block;
  width: 44px;
  height: 2px;
  margin-bottom: 16px;
  background: var(--cyan);
}

.page-about .about-hero__facts {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: 0;
  background: var(--about-hair);
  border: 1px solid var(--about-hair);
}

.page-about .about-hero__facts > div {
  background: var(--green-900);
  padding: 14px 16px;
}

.page-about .about-hero__facts dt {
  font-size: 11px;
  letter-spacing: .16em;
  color: var(--mist-400);
}

.page-about .about-hero__facts dd {
  margin: 8px 0 0;
  font-family: var(--font-mono);
  font-size: clamp(22px, 3.4vw, 32px);
  font-weight: 700;
  letter-spacing: -.02em;
  color: var(--mist-100);
  font-variant-numeric: tabular-nums;
}

.page-about .about-hero__media {
  margin: 34px 0 0;
}

/* ---------- 起点判定 ---------- */
.page-about .about-origin__grid {
  display: grid;
  gap: 24px;
  margin-top: 26px;
}

.page-about .about-origin__plate {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 10px 14px;
  padding: 20px;
  background: var(--green-900);
  border: 1px solid var(--line-500);
  border-left: 2px solid var(--gold);
}

.page-about .about-origin__year {
  font-family: var(--font-mono);
  font-size: clamp(42px, 10vw, 82px);
  line-height: .88;
  font-weight: 700;
  letter-spacing: -.035em;
  color: var(--gold);
  font-variant-numeric: tabular-nums;
}

.page-about .about-origin__plate-note {
  flex: 1 1 100%;
  font-size: 11px;
  letter-spacing: .16em;
  color: var(--mist-400);
}

.page-about .about-origin__text h2 {
  margin: 0 0 16px;
  font-size: var(--step-2);
  font-weight: 700;
  letter-spacing: -.015em;
  color: var(--mist-100);
}

.page-about .about-origin__text p {
  margin: 0 0 14px;
  font-size: var(--step-0);
  line-height: 1.78;
  color: var(--mist-100);
}

.page-about .about-origin__list {
  margin: 22px 0 0;
  padding: 0;
  list-style: none;
  border-top: 1px solid var(--line-500);
}

.page-about .about-origin__list li {
  display: grid;
  grid-template-columns: 80px minmax(0, 1fr);
  gap: 14px;
  padding: 13px 0;
  border-bottom: 1px solid var(--about-hair);
  font-size: var(--step--1);
  line-height: 1.68;
}

.page-about .about-origin__k {
  font-family: var(--font-mono);
  letter-spacing: .06em;
  color: var(--cyan);
}

.page-about .about-origin__v {
  color: var(--mist-100);
}

/* ---------- 三段式登记 ---------- */
.page-about .about-record__h {
  margin: 22px 0 0;
  font-size: var(--step-2);
  font-weight: 700;
  letter-spacing: -.015em;
  color: var(--mist-100);
}

.page-about .about-record__intro {
  margin: 16px 0 0;
  max-width: 70ch;
  font-size: var(--step-0);
  line-height: 1.78;
  color: var(--mist-100);
}

.page-about .about-record__grid {
  display: grid;
  gap: 30px;
  margin-top: 30px;
}

.page-about .about-record__steps {
  margin: 0;
  padding: 0;
  list-style: none;
  counter-reset: rec;
}

.page-about .about-record__steps li {
  position: relative;
  margin-left: 13px;
  padding: 0 0 24px 34px;
  border-left: 1px solid var(--line-500);
}

.page-about .about-record__steps li:last-child {
  padding-bottom: 0;
  border-left-color: transparent;
}

.page-about .about-record__steps li::before {
  counter-increment: rec;
  content: "0" counter(rec);
  position: absolute;
  left: -1px;
  top: 0;
  transform: translateX(-50%);
  width: 26px;
  height: 26px;
  display: grid;
  place-items: center;
  background: var(--ink-950);
  border: 1px solid var(--line-500);
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--cyan);
}

.page-about .about-record__steps h3 {
  margin: 2px 0 8px;
  font-size: var(--step-1);
  font-weight: 700;
  color: var(--mist-100);
}

.page-about .about-record__steps p {
  margin: 0;
  font-size: var(--step--1);
  line-height: 1.72;
  color: var(--mist-100);
}

.page-about .about-record__media {
  margin: 0;
  border: 1px solid var(--line-500);
}

.page-about .about-record__demo {
  margin-top: 30px;
}

.page-about .about-sample {
  max-width: 760px;
}

.page-about .about-sample__meta {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
  gap: 1px;
  margin: 16px 0 0;
  background: var(--about-hair);
  border: 1px solid var(--about-hair);
}

.page-about .about-sample__meta > div {
  background: var(--ink-950);
  padding: 10px 12px;
}

.page-about .about-sample__meta dt {
  font-size: 11px;
  letter-spacing: .14em;
  color: var(--mist-400);
}

.page-about .about-sample__meta dd {
  margin: 6px 0 0;
  font-family: var(--font-mono);
  font-size: var(--step-0);
  color: var(--mist-100);
  font-variant-numeric: tabular-nums;
}

.page-about .about-sample .fold {
  margin-top: 16px;
}

/* ---------- 任期轴 ---------- */
.page-about .about-axis__h {
  margin: 22px 0 0;
  font-size: var(--step-2);
  font-weight: 700;
  letter-spacing: -.015em;
  color: var(--mist-100);
}

.page-about .about-axis__intro {
  margin: 16px 0 0;
  max-width: 70ch;
  font-size: var(--step-0);
  line-height: 1.78;
  color: var(--mist-100);
}

.page-about .about-axis__figure {
  margin: 26px 0 0;
  border: 1px solid var(--line-500);
}

.page-about .about-tl {
  position: relative;
  margin: 32px 0 0;
  padding: 0 0 0 var(--tl-gap);
  list-style: none;
}

.page-about .about-tl::before {
  content: "";
  position: absolute;
  left: var(--tl-rail);
  top: 8px;
  bottom: 8px;
  width: 1px;
  background: linear-gradient(
    180deg,
    var(--gold) 0%,
    var(--line-500) 16%,
    var(--line-500) 100%
  );
}

.page-about .about-tl__item {
  position: relative;
  padding: 0 0 30px;
}

.page-about .about-tl__item:last-child {
  padding-bottom: 0;
}

.page-about .about-tl__item::before {
  content: "";
  position: absolute;
  left: calc(var(--tl-rail) - var(--tl-gap) - 5px);
  top: 16px;
  width: 11px;
  height: 11px;
  box-sizing: border-box;
  background: var(--ink-950);
  border: 1px solid var(--line-500);
}

.page-about .about-tl__item--gold::before {
  background: var(--gold);
  border-color: var(--gold);
  box-shadow: 0 0 0 4px rgba(217, 180, 94, .16);
}

.page-about .about-tl__k {
  display: block;
  margin-bottom: 8px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .14em;
  color: var(--mist-400);
  font-variant-numeric: tabular-nums;
}

.page-about .about-tl__item--gold .about-tl__k {
  color: var(--gold);
}

.page-about .about-tl__card {
  padding: 18px 18px 16px;
  background: var(--green-900);
  border: 1px solid var(--line-500);
  transition: border-color var(--ease), background-color var(--ease);
}

.page-about .about-tl__item:hover .about-tl__card,
.page-about .about-tl__item:focus-within .about-tl__card {
  border-color: var(--cyan);
  background: var(--green-700);
}

.page-about .about-tl__id {
  display: inline-block;
  margin-bottom: 10px;
  padding: 2px 7px;
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: .16em;
  color: var(--cyan);
  border: 1px solid var(--line-500);
}

.page-about .about-tl__card h3 {
  margin: 0 0 8px;
  font-size: var(--step-1);
  font-weight: 700;
  color: var(--mist-100);
}

.page-about .about-tl__card p {
  margin: 0;
  font-size: var(--step--1);
  line-height: 1.72;
  color: var(--mist-100);
}

.page-about .about-tl__meter {
  display: grid;
  grid-template-columns: 76px minmax(0, 1fr) 46px;
  align-items: center;
  gap: 10px;
  margin-top: 14px;
  padding-top: 12px;
  border-top: 1px solid var(--about-hair);
}

.page-about .about-tl__meter-k {
  font-size: 11px;
  letter-spacing: .1em;
  color: var(--mist-400);
}

.page-about .about-tl__meter .meter {
  height: 6px;
}

.page-about .about-tl__meter-v {
  font-family: var(--font-mono);
  font-size: 13px;
  text-align: right;
  color: var(--mist-100);
  font-variant-numeric: tabular-nums;
}

/* ---------- 修订留痕 ---------- */
.page-about .about-revision__h {
  margin: 22px 0 0;
  font-size: var(--step-2);
  font-weight: 700;
  letter-spacing: -.015em;
  color: var(--mist-100);
}

.page-about .about-revision__grid {
  display: grid;
  gap: 1px;
  margin-top: 26px;
  background: var(--about-hair);
  border: 1px solid var(--about-hair);
}

.page-about .about-revision__cell {
  background: var(--green-900);
  padding: 20px 18px;
  border-left: 2px solid transparent;
  transition: border-color var(--ease), background-color var(--ease);
}

.page-about .about-revision__cell:hover {
  background: var(--green-700);
  border-left-color: var(--orange);
}

.page-about .about-revision__cell h3 {
  margin: 0 0 10px;
  font-size: var(--step-1);
  font-weight: 700;
  color: var(--mist-100);
}

.page-about .about-revision__cell p {
  margin: 0;
  font-size: var(--step--1);
  line-height: 1.72;
  color: var(--mist-100);
}

.page-about .about-revision__fold {
  margin-top: 24px;
  border-top: 1px solid var(--line-500);
  padding-top: 4px;
}

/* ---------- 运营主体 ---------- */
.page-about .about-entity__grid {
  display: grid;
  gap: 26px;
  margin-top: 24px;
}

.page-about .about-entity__text h2 {
  margin: 0 0 16px;
  font-size: var(--step-2);
  font-weight: 700;
  letter-spacing: -.015em;
  color: var(--mist-100);
}

.page-about .about-entity__text p {
  margin: 0 0 14px;
  font-size: var(--step-0);
  line-height: 1.78;
  color: var(--mist-100);
}

.page-about .about-entity__facts {
  margin: 0;
  border: 1px solid var(--line-500);
}

.page-about .about-entity__facts > div {
  display: grid;
  grid-template-columns: 110px minmax(0, 1fr);
  gap: 12px;
  padding: 13px 16px;
  border-bottom: 1px solid var(--about-hair);
}

.page-about .about-entity__facts > div:last-child {
  border-bottom: 0;
}

.page-about .about-entity__facts dt {
  font-size: 11px;
  letter-spacing: .14em;
  color: var(--mist-400);
}

.page-about .about-entity__facts dd {
  margin: 0;
  font-size: var(--step--1);
  line-height: 1.6;
  color: var(--mist-100);
  overflow-wrap: anywhere;
}

.page-about .about-entity__mail {
  font-family: var(--font-mono);
}

/* ---------- 引用路径 ---------- */
.page-about .about-next__h {
  margin: 22px 0 0;
  font-size: var(--step-2);
  font-weight: 700;
  letter-spacing: -.015em;
  color: var(--mist-100);
}

.page-about .about-next__intro {
  margin: 16px 0 0;
  max-width: 70ch;
  font-size: var(--step-0);
  line-height: 1.78;
  color: var(--mist-100);
}

.page-about .about-next__grid {
  display: grid;
  gap: 1px;
  margin-top: 26px;
  background: var(--about-hair);
  border: 1px solid var(--about-hair);
}

.page-about .about-next__link {
  display: block;
  padding: 22px 20px;
  background: var(--green-900);
  color: inherit;
  text-decoration: none;
  transition: background-color var(--ease), box-shadow var(--ease);
}

.page-about .about-next__link:hover,
.page-about .about-next__link:focus-visible {
  background: var(--green-700);
  box-shadow: inset 2px 0 0 var(--cyan);
  outline: none;
}

.page-about .about-next__num {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .18em;
  color: var(--cyan);
}

.page-about .about-next__link h3 {
  margin: 10px 0 8px;
  font-size: var(--step-1);
  font-weight: 700;
  color: var(--mist-100);
}

.page-about .about-next__link p {
  margin: 0;
  font-size: var(--step--1);
  line-height: 1.72;
  color: var(--mist-100);
}

.page-about .about-next__foot {
  margin: 22px 0 0;
  font-size: var(--step--1);
  line-height: 1.72;
  color: var(--mist-400);
}

.page-about .about-next__foot a {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid var(--line-500);
  transition: border-color var(--ease), color var(--ease);
}

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

/* ---------- 响应式 ---------- */
@media (min-width: 720px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 1.55fr) minmax(0, 1fr);
    align-items: end;
    gap: 40px;
  }

  .page-about .about-origin__grid {
    grid-template-columns: minmax(0, 280px) minmax(0, 1fr);
    gap: 40px;
    align-items: start;
  }

  .page-about .about-record__grid {
    grid-template-columns: minmax(0, 1fr) minmax(0, 320px);
    gap: 40px;
    align-items: start;
  }

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

  .page-about .about-entity__grid {
    grid-template-columns: minmax(0, 1fr) minmax(0, 380px);
    gap: 40px;
    align-items: start;
  }

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

@media (min-width: 900px) {
  .page-about {
    --tl-gap: 132px;
  }

  .page-about .about-tl__item {
    display: grid;
    grid-template-columns: 112px minmax(0, 1fr);
    gap: 20px;
    align-items: start;
  }

  .page-about .about-tl__k {
    margin-bottom: 0;
    padding-top: 18px;
    text-align: right;
  }

  .page-about .about-tl__card {
    max-width: 780px;
  }
}

@media (min-width: 1120px) {
  .page-about .about-hero__facts {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-index a,
  .page-about .about-tl__card,
  .page-about .about-revision__cell,
  .page-about .about-next__link,
  .page-about .about-next__foot a {
    transition: none;
  }
}