.page-about {
  --ab-rail: 132px;
  --ab-block: clamp(28px, 4.4vw, 56px);
}

.page-about .ab-crumb {
  padding-top: clamp(18px, 3vw, 32px);
}

.page-about .ab-head__note {
  font-size: .78rem;
  letter-spacing: .06em;
  color: var(--index-gray);
  margin: 0;
}

/* ---------- 首屏 ---------- */

.page-about .ab-hero {
  padding-top: clamp(18px, 3vw, 34px);
  padding-bottom: var(--ab-block);
}

.page-about .ab-hero__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--ab-block);
}

@media (min-width: 920px) {
  .page-about .ab-hero__grid {
    grid-template-columns: minmax(0, 1.06fr) minmax(0, .94fr);
    align-items: start;
    gap: clamp(32px, 5vw, 76px);
  }
}

.page-about .ab-hero h1 {
  font-family: var(--font-display);
  font-size: var(--step-1);
  line-height: 1.14;
  letter-spacing: -.02em;
  margin: clamp(12px, 2vw, 20px) 0 0;
}

.page-about .ab-hero .lede {
  margin-top: clamp(16px, 2.4vw, 26px);
  max-width: 46em;
}

.page-about .ab-facts {
  list-style: none;
  margin: clamp(26px, 4vw, 42px) 0 0;
  padding: 2px;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
  gap: 2px;
  background: var(--mortar-light);
  border: 2px solid var(--mortar-deep);
}

.page-about .ab-facts > li {
  background: var(--brick);
  padding: 14px 16px;
  display: flex;
  flex-direction: column;
  gap: 6px;
  min-width: 0;
}

.page-about .ab-facts__num {
  font-size: clamp(1.05rem, 2.2vw, 1.4rem);
  font-weight: 700;
  line-height: 1.1;
  letter-spacing: -.01em;
  color: var(--stoppage);
  overflow-wrap: break-word;
}

.page-about .ab-facts__label {
  font-size: .8rem;
  line-height: 1.5;
  color: var(--index-gray);
}

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

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

/* ---------- 区块标题 ---------- */

.page-about .ab-timeline h2,
.page-about .ab-versions h2,
.page-about .ab-team h2,
.page-about .ab-review h2,
.page-about .ab-meta h2 {
  font-family: var(--font-display);
  font-size: var(--step-2);
  line-height: 1.2;
  letter-spacing: -.015em;
  margin: 0;
}

.page-about .ab-intro {
  margin: clamp(18px, 2.4vw, 26px) 0 0;
  max-width: 68ch;
  line-height: 1.78;
  color: rgba(239, 235, 225, .84);
}

.page-about .ab-intro--ink {
  color: #4a4741;
}

/* ---------- 时间轴 ---------- */

.page-about .ab-track {
  list-style: none;
  margin: clamp(10px, 1.8vw, 18px) 0 0;
  padding: 0;
}

.page-about .ab-step {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 10px;
  padding: clamp(22px, 3.2vw, 34px) 0;
  border-top: 1px solid var(--seam-dark);
}

.page-about .ab-step:first-child {
  border-top: 2px solid var(--mortar-deep);
}

@media (min-width: 860px) {
  .page-about .ab-step {
    grid-template-columns: var(--ab-rail) minmax(0, 1fr);
    gap: clamp(24px, 4vw, 60px);
    align-items: start;
  }
}

.page-about .ab-step__year {
  font-size: clamp(1.4rem, 2.8vw, 1.9rem);
  font-weight: 700;
  line-height: 1;
  letter-spacing: .02em;
  color: var(--pitch);
  margin: 0;
  padding-left: 16px;
  position: relative;
  transition: color var(--dur) var(--ease);
}

.page-about .ab-step__year::before {
  content: "";
  position: absolute;
  left: 0;
  top: .24em;
  width: 8px;
  height: 8px;
  background: var(--pitch-soft);
  transition: background-color var(--dur) var(--ease);
}

.page-about .ab-step:hover .ab-step__year,
.page-about .ab-step:focus-within .ab-step__year {
  color: var(--stoppage);
}

.page-about .ab-step:hover .ab-step__year::before,
.page-about .ab-step:focus-within .ab-step__year::before {
  background: var(--stoppage);
}

.page-about .ab-step__body h3 {
  font-family: var(--font-display);
  font-size: var(--step-3);
  line-height: 1.3;
  letter-spacing: -.01em;
  margin: 0 0 10px;
}

.page-about .ab-step__body p {
  margin: 0;
  max-width: 62ch;
  line-height: 1.8;
}

/* ---------- 版本对照 ---------- */

.page-about .ab-versions {
  padding-bottom: var(--ab-block);
}

.page-about .vtab-nav {
  list-style: none;
  margin: clamp(22px, 3vw, 32px) 0 clamp(18px, 2.6vw, 26px);
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.page-about .vtab-nav a {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: .8rem;
  letter-spacing: .02em;
  text-decoration: none;
  color: var(--mortar-light);
  padding: 9px 14px;
  border: 2px solid var(--seam);
  transition: border-color var(--dur) var(--ease), background-color var(--dur) var(--ease), color var(--dur) var(--ease);
}

.page-about .vtab-nav a:hover,
.page-about .vtab-nav a:focus-visible {
  border-color: var(--pitch);
  background: var(--pitch);
  color: var(--mortar-light);
}

.page-about .vpanel {
  border: 2px solid var(--mortar-deep);
  border-left: 6px solid var(--pitch);
  background: var(--scoreboard);
  padding: clamp(20px, 2.8vw, 30px);
  scroll-margin-top: 110px;
}

.page-about .vpanel__title {
  font-family: var(--font-display);
  font-size: var(--step-3);
  line-height: 1.25;
  letter-spacing: -.01em;
  margin: 0;
}

.page-about .vpanel__season {
  margin: 8px 0 0;
  font-size: .8rem;
  letter-spacing: .04em;
  color: var(--pitch-soft);
}

.page-about .vpanel__grid {
  margin: clamp(16px, 2.2vw, 24px) 0 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  background: var(--seam);
}

.page-about .vpanel__grid > div {
  background: var(--scoreboard);
  padding: 12px 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 4px;
}

@media (min-width: 720px) {
  .page-about .vpanel__grid > div {
    grid-template-columns: 150px minmax(0, 1fr);
    gap: 20px;
    align-items: baseline;
  }
}

.page-about .vpanel__grid dt {
  font-family: var(--font-mono);
  font-size: .78rem;
  letter-spacing: .05em;
  color: var(--index-gray);
}

.page-about .vpanel__grid dd {
  margin: 0;
  line-height: 1.74;
  color: var(--mortar-light);
}

@supports selector(:has(*)) {
  .page-about .vpanel {
    display: none;
  }

  .page-about .vtabs:not(:has(.vpanel:target)) .vpanel:first-of-type {
    display: block;
  }

  .page-about .vpanel:target {
    display: block;
  }
}

.page-about .ab-versions__figure {
  margin: clamp(30px, 4vw, 46px) 0 0;
}

.page-about .ab-versions__more {
  margin: clamp(20px, 2.6vw, 28px) 0 0;
  max-width: 68ch;
  line-height: 1.76;
  color: rgba(239, 235, 225, .84);
}

.page-about .ab-versions a {
  color: var(--pitch-soft);
}

/* ---------- 团队分工 ---------- */

.page-about .ab-roles {
  list-style: none;
  margin: clamp(22px, 3vw, 32px) 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  background: var(--seam-dark);
  border: 2px solid var(--mortar-deep);
}

.page-about .ab-role {
  background: var(--mortar-light);
  padding: 16px 18px;
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  grid-template-areas:
    "name num"
    "desc desc"
    "bar bar";
  gap: 6px 16px;
  align-items: baseline;
}

@media (min-width: 720px) {
  .page-about .ab-role {
    grid-template-columns: 168px 84px minmax(0, 1fr);
    grid-template-areas:
      "name num desc"
      "bar bar bar";
    gap: 6px 24px;
  }
}

.page-about .ab-role__name {
  grid-area: name;
  font-weight: 700;
}

.page-about .ab-role__num {
  grid-area: num;
  font-weight: 700;
  color: var(--pitch);
}

.page-about .ab-role__desc {
  grid-area: desc;
  font-size: .92rem;
  line-height: 1.7;
  color: #4a4741;
}

.page-about .ab-role__bar {
  grid-area: bar;
  display: block;
  height: 10px;
  margin-top: 6px;
  background: rgba(38, 37, 33, .12);
}

.page-about .ab-role__bar > span {
  display: block;
  height: 100%;
  width: var(--share, 12%);
  background: var(--pitch);
}

.page-about .ab-role--check { --share: 46.2%; }
.page-about .ab-role--visit { --share: 23.1%; }
.page-about .ab-role--rule  { --share: 15.4%; }
.page-about .ab-role--edit  { --share: 15.4%; }

.page-about .ab-sub-h {
  font-family: var(--font-display);
  font-size: var(--step-3);
  line-height: 1.3;
  letter-spacing: -.01em;
  margin: clamp(38px, 5vw, 58px) 0 0;
}

.page-about .ab-flow {
  list-style: none;
  margin: clamp(20px, 2.6vw, 28px) 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  border-top: 2px solid var(--mortar-deep);
}

@media (min-width: 760px) {
  .page-about .ab-flow {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

.page-about .ab-flow > li {
  padding: 16px 0;
  border-bottom: 1px solid var(--seam-dark);
}

@media (min-width: 760px) {
  .page-about .ab-flow > li {
    border-bottom: 0;
    border-left: 1px solid var(--seam-dark);
    padding: 20px 22px;
  }

  .page-about .ab-flow > li:first-child {
    border-left: 0;
    padding-left: 0;
  }
}

.page-about .ab-flow__time {
  display: block;
  font-size: .92rem;
  font-weight: 700;
  letter-spacing: .04em;
  color: var(--stoppage);
}

.page-about .ab-flow > li p {
  margin: 8px 0 0;
  font-size: .94rem;
  line-height: 1.72;
  color: #4a4741;
}

.page-about .ab-note {
  margin: clamp(22px, 3vw, 30px) 0 0;
  padding-left: 14px;
  border-left: 4px solid var(--pitch-soft);
  font-size: .93rem;
  line-height: 1.78;
  color: #4a4741;
}

/* ---------- 看台复核 ---------- */

.page-about .ab-review {
  padding-bottom: var(--ab-block);
}

.page-about .ab-review__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--ab-block);
  margin-top: clamp(20px, 3vw, 32px);
}

@media (min-width: 920px) {
  .page-about .ab-review__grid {
    grid-template-columns: minmax(0, 1.55fr) minmax(0, .45fr);
    gap: clamp(32px, 5vw, 72px);
    align-items: start;
  }
}

.page-about .ab-review__text > p {
  margin: 0;
  max-width: 62ch;
  line-height: 1.8;
}

.page-about .ab-checks {
  list-style: none;
  margin: clamp(20px, 2.6vw, 28px) 0 0;
  padding: 0;
}

.page-about .ab-checks > li {
  display: grid;
  grid-template-columns: 40px minmax(0, 1fr);
  gap: 16px;
  padding: 16px 0;
  border-top: 1px solid var(--seam);
  line-height: 1.76;
}

.page-about .ab-checks .mono {
  font-size: .8rem;
  letter-spacing: .08em;
  color: var(--stoppage);
}

.page-about .ab-review__aside {
  border: 2px solid var(--mortar-deep);
  background: var(--scoreboard);
  padding: clamp(18px, 2.4vw, 24px);
}

.page-about .ab-review__stat + .ab-review__stat {
  margin-top: 22px;
  padding-top: 22px;
  border-top: 1px solid var(--seam);
}

.page-about .ab-review__num {
  margin: 0;
  font-size: clamp(2.3rem, 6vw, 3.2rem);
  font-weight: 700;
  line-height: 1;
  color: var(--stoppage);
}

.page-about .ab-review__label {
  margin: 8px 0 0;
  font-size: .86rem;
  line-height: 1.6;
  color: var(--index-gray);
}

.page-about .ab-review__more {
  margin: clamp(26px, 3.4vw, 38px) 0 0;
  font-size: .94rem;
  line-height: 1.78;
  color: rgba(239, 235, 225, .84);
}

.page-about .ab-review__more a {
  color: var(--pitch-soft);
}

/* ---------- 站点信息 ---------- */

.page-about .ab-meta {
  padding-bottom: var(--ab-block);
}

.page-about .ab-meta__figure {
  margin: clamp(20px, 3vw, 32px) 0 clamp(24px, 3.4vw, 36px);
}

.page-about .ab-meta__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  background: var(--seam-dark);
  border: 2px solid var(--mortar-deep);
}

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

.page-about .ab-meta__list > li {
  background: var(--mortar-light);
  padding: 13px 16px;
  display: flex;
  flex-wrap: wrap;
  gap: 4px 14px;
  align-items: baseline;
  min-width: 0;
}

.page-about .ab-meta__key {
  font-size: .76rem;
  letter-spacing: .06em;
  color: #6f6a60;
  flex: 0 0 auto;
}

.page-about .ab-meta__val {
  font-weight: 700;
  min-width: 0;
  overflow-wrap: break-word;
}

.page-about .ab-meta__note {
  margin: clamp(20px, 2.6vw, 28px) 0 0;
  max-width: 68ch;
  font-size: .93rem;
  line-height: 1.8;
  color: #4a4741;
}

.page-about .ab-meta__links {
  margin: clamp(18px, 2.4vw, 26px) 0 0;
  display: flex;
  flex-wrap: wrap;
  gap: 10px 22px;
  font-family: var(--font-mono);
  font-size: .84rem;
}

.page-about .ab-meta__links a {
  color: var(--pitch);
  text-decoration: none;
  padding-bottom: 2px;
  border-bottom: 2px solid rgba(46, 107, 69, .32);
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.page-about .ab-meta__links a:hover,
.page-about .ab-meta__links a:focus-visible {
  color: var(--stoppage);
  border-color: var(--stoppage);
}

.page-about .ab-totop {
  margin: clamp(28px, 4vw, 44px) 0 0;
  padding-top: 16px;
  border-top: 1px solid var(--seam-dark);
  font-family: var(--font-mono);
  font-size: .82rem;
}

.page-about .ab-totop a {
  color: #6f6a60;
  text-decoration: none;
  border-bottom: 1px solid currentColor;
  transition: color var(--dur) var(--ease);
}

.page-about .ab-totop a:hover,
.page-about .ab-totop a:focus-visible {
  color: var(--stoppage);
}

/* ---------- 深底区块的链接与正文色 ---------- */

.page-about .section--paper {
  color: var(--mortar-deep);
}

.page-about .section--paper a {
  color: var(--pitch);
}

.page-about .ab-team a,
.page-about .ab-meta a.ab-inline {
  text-decoration: none;
  border-bottom: 1px solid rgba(46, 107, 69, .4);
  transition: border-color var(--dur) var(--ease), color var(--dur) var(--ease);
}

.page-about .ab-team a:hover,
.page-about .ab-team a:focus-visible {
  color: var(--stoppage);
  border-color: var(--stoppage);
}

@media (prefers-reduced-motion: reduce) {
  .page-about *,
  .page-about *::before,
  .page-about *::after {
    transition: none !important;
  }
}