.page-about {
  --ab-ink-soft: #405A62;
  --ab-ink-faint: #5C757D;
  --ab-panel-pad: 20px;
  --ab-focus: 0 0 0 2px rgba(255, 107, 44, .55);
  padding-bottom: 56px;
}

.page-about .ab-shell {
  padding-top: 16px;
}

/* ---------- 面包屑 ---------- */
.page-about .breadcrumbs {
  font-size: 11px;
  letter-spacing: .1em;
  text-transform: uppercase;
  color: var(--mist);
  margin-bottom: 16px;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 6px;
}

.page-about .breadcrumbs a {
  color: var(--mist);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color var(--ease), border-color var(--ease);
}

.page-about .breadcrumbs a:hover,
.page-about .breadcrumbs a:focus-visible {
  color: var(--flame);
  border-bottom-color: var(--flame);
}

.page-about .ab-crumb-sep {
  color: rgba(147, 174, 181, .5);
}

/* ---------- 首屏 ---------- */
.page-about .ab-hero {
  display: grid;
  gap: 20px;
  padding-bottom: 26px;
  border-bottom: var(--line-sand);
}

.page-about .ab-hero-copy {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.page-about .sec-eyebrow {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .16em;
  text-transform: uppercase;
  color: var(--sand);
}

.page-about .ab-h1 {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(29px, 8.2vw, 52px);
  line-height: 1.05;
  letter-spacing: -.015em;
  color: var(--paper);
}

.page-about .ab-lede {
  margin: 0;
  max-width: 40ch;
  font-size: 15px;
  line-height: 1.85;
  color: var(--mist);
}

.page-about .ab-hero-tags {
  list-style: none;
  margin: 4px 0 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.page-about .ab-hero-figure {
  margin: 0;
}

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

.page-about .ab-hero-figure img {
  aspect-ratio: 16 / 9;
  border: var(--line-soft);
}

/* ---------- 段落标题统一 ---------- */
.page-about .sec-label {
  font-family: var(--font-mono);
  letter-spacing: .14em;
}

.page-about .ab-canon,
.page-about .ab-tiers,
.page-about .ab-seasons,
.page-about .ab-division,
.page-about .ab-stages {
  padding-top: 34px;
}

.page-about .ab-fields {
  padding-top: 34px;
}

/* ---------- 01 口径总表 ---------- */
.page-about .ab-canon-grid {
  display: grid;
  gap: 16px;
  margin-top: 16px;
}

.page-about .ab-canon-list {
  list-style: none;
  margin: 0;
  padding: 0;
  border-top: var(--line-soft);
}

.page-about .ab-canon-row {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 2px 14px;
  padding: 13px 10px 13px 12px;
  border-bottom: var(--line-soft);
  border-left: 3px solid transparent;
  transition: background var(--ease-mid), border-color var(--ease-mid);
  outline: none;
}

.page-about .ab-canon-row:hover,
.page-about .ab-canon-row:focus-within {
  background: var(--stand);
  border-left-color: var(--flame);
}

.page-about .ab-canon-row:focus-within {
  box-shadow: var(--ab-focus);
}

.page-about .ab-canon-key {
  margin: 0;
  font-size: 14px;
  font-weight: 700;
  color: var(--paper);
  letter-spacing: .01em;
}

.page-about .ab-canon-val {
  margin: 0;
  font-size: 14px;
  color: var(--flame);
  white-space: nowrap;
}

.page-about .ab-canon-desc {
  grid-column: 1 / -1;
  margin: 0;
  max-width: 42ch;
  font-size: 13px;
  line-height: 1.75;
  color: var(--mist);
}

.page-about .ab-canon-side {
  display: grid;
  gap: 8px;
}

.page-about .ab-canon-note {
  background: var(--stand);
  border-left: 3px solid rgba(216, 179, 106, .32);
  padding: 11px 13px;
  transition: background var(--ease-mid), border-color var(--ease-mid);
}

.page-about .ab-canon-note p {
  margin: 0;
  font-size: 13px;
  line-height: 1.7;
  color: var(--mist);
}

.page-about .ab-note-tag {
  margin-bottom: 5px !important;
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: .18em;
  text-transform: uppercase;
  color: var(--sand);
}

.page-about .ab-canon-grid:has(.ab-canon-row:nth-child(1):hover) .ab-canon-note:nth-child(1),
.page-about .ab-canon-grid:has(.ab-canon-row:nth-child(1):focus-within) .ab-canon-note:nth-child(1),
.page-about .ab-canon-grid:has(.ab-canon-row:nth-child(2):hover) .ab-canon-note:nth-child(2),
.page-about .ab-canon-grid:has(.ab-canon-row:nth-child(2):focus-within) .ab-canon-note:nth-child(2),
.page-about .ab-canon-grid:has(.ab-canon-row:nth-child(3):hover) .ab-canon-note:nth-child(3),
.page-about .ab-canon-grid:has(.ab-canon-row:nth-child(3):focus-within) .ab-canon-note:nth-child(3),
.page-about .ab-canon-grid:has(.ab-canon-row:nth-child(4):hover) .ab-canon-note:nth-child(4),
.page-about .ab-canon-grid:has(.ab-canon-row:nth-child(4):focus-within) .ab-canon-note:nth-child(4),
.page-about .ab-canon-grid:has(.ab-canon-row:nth-child(5):hover) .ab-canon-note:nth-child(5),
.page-about .ab-canon-grid:has(.ab-canon-row:nth-child(5):focus-within) .ab-canon-note:nth-child(5) {
  background: rgba(255, 107, 44, .13);
  border-left-color: var(--flame);
}

/* ---------- 面板 ---------- */
.page-about .ab-panel {
  padding: var(--ab-panel-pad);
  border: var(--line-ink);
}

.page-about .ab-panel--paper {
  background: var(--paper);
  color: var(--ink);
  border-color: rgba(8, 21, 26, .22);
}

.page-about .ab-panel--paper .sec-label {
  color: var(--ab-ink-soft);
}

.page-about .ab-panel--paper .sec-title {
  color: var(--ink);
}

.page-about .ab-panel--paper .sec-note {
  color: var(--ab-ink-faint);
}

.page-about .ab-panel--sand {
  background: var(--sand-paper);
  color: var(--ink);
  border-color: rgba(8, 21, 26, .2);
}

.page-about .ab-panel--sand .sec-label {
  color: var(--ab-ink-soft);
}

.page-about .ab-panel--sand .sec-title {
  color: var(--ink);
}

/* ---------- 02 字段构成 ---------- */
.page-about .ab-fields-body {
  display: grid;
  gap: 22px;
  margin-top: 18px;
}

.page-about .ab-field-list {
  list-style: none;
  margin: 0;
  padding: 0;
  border-top: var(--line-ink);
}

.page-about .ab-field-item {
  display: grid;
  grid-template-columns: 38px minmax(0, 1fr);
  gap: 12px;
  padding: 12px 0;
  border-bottom: var(--line-ink);
}

.page-about .ab-field-no {
  display: block;
  font-size: 12px;
  font-weight: 700;
  letter-spacing: .08em;
  color: var(--ink);
  padding-top: 2px;
}

.page-about .ab-field-no::before {
  content: "";
  display: block;
  width: 14px;
  height: 2px;
  margin-bottom: 5px;
  background: var(--flame);
}

.page-about .ab-field-name {
  margin: 0 0 3px;
  font-family: var(--font-body);
  font-size: 14.5px;
  font-weight: 700;
  letter-spacing: .01em;
  color: var(--ink);
}

.page-about .ab-field-text {
  margin: 0;
  max-width: 40ch;
  font-size: 13.5px;
  line-height: 1.8;
  color: var(--ab-ink-soft);
}

.page-about .ab-fields-side {
  display: grid;
  gap: 14px;
  align-content: start;
}

.page-about .ab-fields-side .img-frame {
  margin: 0;
}

.page-about .ab-fields-side .img-frame img {
  aspect-ratio: 3 / 2;
  border: var(--line-ink);
}

.page-about .ab-plate {
  border: var(--line-ink);
}

.page-about .ab-panel--paper .ab-plate {
  background: rgba(216, 179, 106, .16);
}

.page-about .ab-plate-title {
  margin: 0 0 6px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .12em;
  text-transform: uppercase;
  color: var(--ab-ink-soft);
}

.page-about .ab-plate p:last-child {
  margin-bottom: 0;
  font-size: 13.5px;
  line-height: 1.8;
  color: var(--ab-ink-soft);
}

/* ---------- 03 梯队编号 ---------- */
.page-about .ab-tier-strip {
  list-style: none;
  margin: 18px 0 0;
  padding: 0 0 6px;
  display: flex;
  gap: 8px;
  overflow-x: auto;
  scroll-snap-type: x mandatory;
  -webkit-overflow-scrolling: touch;
}

.page-about .ab-tier {
  position: relative;
  flex: 0 0 auto;
  scroll-snap-align: start;
  min-width: 82px;
  display: flex;
  flex-direction: column;
  gap: 3px;
  padding: 11px 14px 11px 16px;
  border: var(--line-sand);
  background: linear-gradient(180deg, rgba(216, 179, 106, .16), rgba(216, 179, 106, .03));
}

.page-about .ab-tier::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 3px;
  background: var(--sand);
}

.page-about .ab-tier-code {
  font-size: 17px;
  font-weight: 700;
  color: var(--sand);
  letter-spacing: .02em;
}

.page-about .ab-tier-note {
  font-size: 11px;
  letter-spacing: .06em;
  color: var(--mist);
}

.page-about .ab-tiers-body {
  display: grid;
  gap: 20px;
  margin-top: 20px;
}

.page-about .ab-tiers-text p {
  margin: 0 0 14px;
  max-width: 40ch;
  font-size: 14px;
  line-height: 1.85;
  color: var(--mist);
}

.page-about .ab-tiers-text p:last-child {
  margin-bottom: 0;
}

.page-about .ab-tier-figure {
  margin: 0;
}

.page-about .ab-tier-figure img {
  aspect-ratio: 12 / 7;
  border: var(--line-sand);
}

/* ---------- 04 赛季档位 ---------- */
.page-about .ab-season-stack {
  list-style: none;
  margin: 18px 0 0;
  padding: 0;
  display: grid;
  gap: 10px;
}

.page-about .ab-season-card {
  background: var(--stand);
  border: var(--line-soft);
  border-left: 4px solid var(--sand);
  padding: 14px 16px;
}

.page-about .ab-season-card:nth-child(2) {
  margin-left: 10px;
}

.page-about .ab-season-card:nth-child(3) {
  margin-left: 20px;
}

.page-about .ab-season-tag {
  margin: 0 0 6px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .14em;
  text-transform: uppercase;
  color: var(--sand);
}

.page-about .ab-season-text {
  margin: 0;
  max-width: 46ch;
  font-size: 13.5px;
  line-height: 1.8;
  color: var(--mist);
}

.page-about .ab-season-note {
  margin-top: 16px;
}

.page-about .ab-season-note .ab-plate-title {
  color: var(--sand);
}

.page-about .ab-season-note p:last-child {
  color: var(--mist);
}

/* ---------- 05 栏目分工 ---------- */
.page-about .ab-div-grid {
  display: grid;
  gap: 12px;
  margin-top: 18px;
}

.page-about .ab-div-item {
  padding: 16px;
  border: var(--line-soft);
  border-top: 3px solid var(--flame);
  background: rgba(19, 62, 74, .55);
}

.page-about .ab-div-idx {
  margin: 0 0 8px;
  font-size: 12px;
  letter-spacing: .14em;
  color: var(--flame);
}

.page-about .ab-div-name {
  margin: 0 0 6px;
  font-family: var(--font-display);
  font-size: 18px;
  font-weight: 700;
  letter-spacing: .01em;
  color: var(--paper);
}

.page-about .ab-div-text {
  margin: 0 0 10px;
  font-size: 13.5px;
  line-height: 1.8;
  color: var(--mist);
}

.page-about .ab-div-link {
  margin: 0;
}

.page-about .ab-link {
  color: var(--flame);
  text-decoration: none;
  font-size: 13px;
  border-bottom: 1px solid rgba(255, 107, 44, .4);
  transition: color var(--ease), border-color var(--ease);
}

.page-about .ab-link:hover,
.page-about .ab-link:focus-visible {
  color: var(--flame-soft);
  border-bottom-color: var(--flame-soft);
}

.page-about .ab-panel--sand .ab-link {
  color: #A8380E;
  border-bottom-color: rgba(168, 56, 14, .45);
}

.page-about .ab-panel--sand .ab-link:hover,
.page-about .ab-panel--sand .ab-link:focus-visible {
  color: #7E2A0B;
  border-bottom-color: #7E2A0B;
}

.page-about .ab-flow {
  margin-top: 24px;
  padding-top: 18px;
  border-top: var(--line-sand);
}

.page-about .ab-flow-title {
  margin: 0 0 12px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .14em;
  text-transform: uppercase;
  color: var(--sand);
}

.page-about .ab-flow-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 10px;
}

.page-about .ab-flow-step {
  display: grid;
  grid-template-columns: 32px minmax(0, 1fr);
  gap: 10px;
  align-items: start;
}

.page-about .ab-flow-no {
  display: block;
  padding-top: 3px;
  font-size: 12px;
  letter-spacing: .08em;
  color: var(--flame);
}

.page-about .ab-flow-step p {
  margin: 0;
  max-width: 46ch;
  font-size: 13.5px;
  line-height: 1.8;
  color: var(--mist);
}

/* ---------- 06 版本演进时间线 ---------- */
.page-about .ab-timeline {
  list-style: none;
  position: relative;
  margin: 20px 0 0;
  padding: 0;
}

.page-about .ab-timeline::before {
  content: "";
  position: absolute;
  left: 9px;
  top: 14px;
  bottom: 14px;
  width: 1px;
  background: rgba(216, 179, 106, .38);
}

.page-about .ab-tl-node {
  position: relative;
  padding-left: 34px;
}

.page-about .ab-tl-det {
  border-bottom: var(--line-soft);
}

.page-about .ab-tl-sum {
  display: flex;
  align-items: baseline;
  gap: 12px;
  padding: 15px 0;
  cursor: pointer;
  list-style: none;
  font-family: var(--font-display);
  font-size: 16.5px;
  font-weight: 700;
  letter-spacing: .01em;
  color: var(--paper);
  transition: color var(--ease);
}

.page-about .ab-tl-sum::-webkit-details-marker {
  display: none;
}

.page-about .ab-tl-sum:hover,
.page-about .ab-tl-sum:focus-visible {
  color: var(--flame);
}

.page-about .ab-tl-sum::after {
  content: "+";
  margin-left: auto;
  padding-left: 10px;
  font-family: var(--font-mono);
  font-size: 15px;
  color: var(--flame);
}

.page-about .ab-tl-det[open] .ab-tl-sum::after {
  content: "−";
}

.page-about .ab-tl-mark {
  position: absolute;
  left: 0;
  top: 19px;
  width: 19px;
  height: 19px;
  background: var(--night);
  border: 1px solid var(--sand);
  transform: rotate(45deg);
}

.page-about .ab-tl-det[open] .ab-tl-mark {
  background: var(--flame);
  border-color: var(--flame);
}

.page-about .ab-tl-step {
  font-size: 12px;
  letter-spacing: .1em;
  color: var(--sand);
}

.page-about .ab-tl-name {
  min-width: 0;
}

.page-about .ab-tl-panel {
  padding: 0 0 16px;
}

.page-about .ab-tl-panel p {
  margin: 0;
  max-width: 44ch;
  font-size: 13.5px;
  line-height: 1.85;
  color: var(--mist);
}

/* ---------- 07 纠错与反馈 ---------- */
.page-about .ab-fix-grid {
  display: grid;
  gap: 20px;
  margin-top: 16px;
}

.page-about .ab-fix-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 14px;
}

.page-about .ab-fix-step {
  display: grid;
  grid-template-columns: 34px minmax(0, 1fr);
  gap: 12px;
  align-items: start;
  padding-bottom: 14px;
  border-bottom: 1px solid rgba(8, 21, 26, .16);
}

.page-about .ab-fix-step:last-child {
  padding-bottom: 0;
  border-bottom: 0;
}

.page-about .ab-fix-no {
  display: block;
  padding-top: 2px;
  font-size: 12px;
  font-weight: 700;
  letter-spacing: .08em;
  color: var(--ink);
}

.page-about .ab-fix-step p {
  margin: 0;
  max-width: 42ch;
  font-size: 13.5px;
  line-height: 1.8;
  color: var(--ab-ink-soft);
}

.page-about .ab-fix-side {
  display: grid;
  gap: 14px;
  align-content: start;
}

.page-about .ab-terms {
  background: rgba(255, 255, 255, .55);
  border: var(--line-ink);
}

.page-about .ab-terms-sum {
  padding: 12px 14px;
  cursor: pointer;
  list-style: none;
  font-size: 13px;
  font-weight: 700;
  color: var(--ink);
  border-left: 3px solid var(--flame);
}

.page-about .ab-terms-sum::-webkit-details-marker {
  display: none;
}

.page-about .ab-terms-sum::after {
  content: " +";
  font-family: var(--font-mono);
  color: var(--ab-ink-soft);
}

.page-about .ab-terms[open] .ab-terms-sum::after {
  content: " −";
}

.page-about .ab-terms-body {
  padding: 0 14px 14px;
}

.page-about .ab-terms-body p {
  margin: 0 0 10px;
  font-size: 13px;
  line-height: 1.8;
  color: var(--ab-ink-soft);
}

.page-about .ab-terms-body p:last-child {
  margin-bottom: 0;
}

.page-about .ab-terms-body strong {
  color: var(--ink);
}

.page-about .ab-panel--sand .ab-plate {
  background: rgba(255, 255, 255, .55);
  border: var(--line-ink);
}

.page-about .ab-panel--sand .ab-plate-title {
  color: var(--ab-ink-soft);
}

.page-about .ab-panel--sand .ab-plate p:last-child {
  color: var(--ab-ink-soft);
}

/* ---------- 收束入口 ---------- */
.page-about .ab-next {
  margin-top: 34px;
  padding-top: 20px;
  border-top: var(--line-sand);
}

.page-about .ab-next-title {
  margin: 0 0 12px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .14em;
  text-transform: uppercase;
  color: var(--sand);
}

.page-about .ab-next-links {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.page-about .ab-next-links .btn {
  flex: 0 1 auto;
}

/* ---------- 响应式 ---------- */
@media (min-width: 640px) {
  .page-about {
    --ab-panel-pad: 26px;
  }

  .page-about .ab-canon-grid {
    grid-template-columns: minmax(0, 1.4fr) minmax(0, .9fr);
    align-items: start;
  }

  .page-about .ab-fields-body {
    grid-template-columns: minmax(0, 1.3fr) minmax(0, .85fr);
    align-items: start;
  }

  .page-about .ab-tiers-body {
    grid-template-columns: minmax(0, 1.1fr) minmax(0, .9fr);
    align-items: start;
  }

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

  .page-about .ab-flow-list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 14px 24px;
  }

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

@media (min-width: 1024px) {
  .page-about .ab-shell {
    padding-top: 26px;
  }

  .page-about {
    --ab-panel-pad: 34px;
  }

  .page-about .ab-hero {
    grid-template-columns: minmax(0, 1.1fr) minmax(0, .9fr);
    align-items: end;
    gap: 32px;
    padding-bottom: 34px;
  }

  .page-about .ab-canon,
  .page-about .ab-tiers,
  .page-about .ab-seasons,
  .page-about .ab-division,
  .page-about .ab-stages,
  .page-about .ab-fields {
    padding-top: 46px;
  }

  .page-about .ab-canon-row {
    padding: 15px 14px;
  }

  .page-about .ab-field-item {
    grid-template-columns: 52px minmax(0, 1fr);
    padding: 14px 0;
  }

  .page-about .ab-div-grid {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .ab-season-card:nth-child(2) {
    margin-left: 20px;
  }

  .page-about .ab-season-card:nth-child(3) {
    margin-left: 40px;
  }

  .page-about .ab-tl-sum {
    font-size: 18px;
  }

  .page-about .ab-next {
    display: flex;
    align-items: baseline;
    gap: 22px;
  }

  .page-about .ab-next-title {
    margin-bottom: 0;
    flex: 0 0 auto;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .ab-canon-row,
  .page-about .ab-canon-note,
  .page-about .ab-link,
  .page-about .ab-tl-sum,
  .page-about .breadcrumbs a {
    transition: none;
  }
}