.page-about {
  --ab-measure: 62ch;
}

/* 面包屑上下文 */
.page-about .ky-breadcrumb {
  padding-top: 28px;
}

/* ---------- 首屏拼贴 ---------- */
.page-about .ab-hero {
  padding-top: 34px;
}

.page-about .ab-hero__eyebrow {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px;
  margin: 0;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--cyan-400);
}

.page-about .ab-hero__eyebrow span {
  color: var(--ink-700);
}

.page-about .ab-hero__title {
  margin: 16px 0 0;
  max-width: 20ch;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(32px, 6.2vw, 66px);
  line-height: 1.07;
  letter-spacing: -0.02em;
  color: var(--paper-050);
}

.page-about .ab-hero__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--gap);
  margin-top: clamp(24px, 4vw, 44px);
}

.page-about .ab-hero__lead {
  margin: 0;
  max-width: var(--ab-measure);
  font-size: 16.5px;
  line-height: 1.78;
  color: var(--slate-300);
}

.page-about .ab-hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 24px;
}

.page-about .ab-index {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--ink-700);
  border: var(--line);
  border-radius: var(--radius-lg);
  overflow: hidden;
}

.page-about .ab-index__item {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 16px 18px 18px;
  background: var(--ink-800);
}

.page-about .ab-index__item:nth-child(5) {
  grid-column: 1 / -1;
}

.page-about .ab-index__num {
  font-family: var(--font-mono);
  font-size: clamp(20px, 5vw, 26px);
  line-height: 1.15;
  font-variant-numeric: tabular-nums;
  color: var(--paper-050);
  letter-spacing: -0.01em;
}

.page-about .ab-index__item:first-child .ab-index__num {
  color: var(--cyan-400);
}

.page-about .ab-index__label {
  font-size: 13px;
  line-height: 1.6;
  color: var(--slate-300);
}

.page-about .ab-hero__figure {
  margin-top: clamp(32px, 5vw, 64px);
}

/* 章节之间的渐变色带 */
.page-about .ab-band {
  height: 2px;
  border-radius: var(--radius-pill);
  background: linear-gradient(90deg, transparent 0%, var(--cyan-400) 22%, var(--violet-500) 62%, transparent 100%);
  opacity: 0.55;
}

/* ---------- 章节公共 ---------- */
.page-about .ab-head {
  display: grid;
  gap: 6px;
  margin-bottom: clamp(24px, 3.4vw, 42px);
}

.page-about .ab-grid-8-4,
.page-about .ab-grid-7-5 {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(26px, 4vw, 44px);
}

.page-about .ab-prose p {
  margin: 0 0 1.1em;
  max-width: var(--ab-measure);
  font-size: 16.5px;
  line-height: 1.78;
  color: var(--slate-300);
}

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

/* 引述式短句 */
.page-about .ab-note {
  border-left: 2px solid var(--cyan-400);
  padding: 2px 0 2px 18px;
}

.page-about .ab-note__text {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 600;
  font-size: clamp(20px, 2.6vw, 27px);
  line-height: 1.42;
  letter-spacing: -0.01em;
  color: var(--paper-050);
}

.page-about .ab-note__meta {
  margin: 14px 0 0;
  font-size: 13px;
  line-height: 1.7;
  color: var(--slate-300);
}

/* ---------- 三类使用场景 ---------- */
.page-about .ab-scenes {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: clamp(22px, 3vw, 34px);
}

.page-about .ab-scenes__item {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: clamp(14px, 2.4vw, 30px);
  border-top: var(--line);
  padding-top: clamp(18px, 2.6vw, 28px);
}

.page-about .ab-scenes__idx {
  padding-top: 6px;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.08em;
  color: var(--cyan-400);
}

.page-about .ab-scenes__title {
  margin: 0 0 10px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(19px, 2.6vw, 27px);
  line-height: 1.3;
  letter-spacing: -0.01em;
  color: var(--paper-050);
}

.page-about .ab-scenes__text {
  margin: 0;
  max-width: 60ch;
  font-size: 15px;
  line-height: 1.8;
  color: var(--slate-300);
}

.page-about .ab-scenes__meta {
  margin: 14px 0 0;
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: 0.02em;
  line-height: 1.7;
  color: var(--cyan-400);
}

/* ---------- 团队 ---------- */
.page-about .ab-team {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 12px;
}

.page-about .ab-team__row {
  padding: 16px 18px 18px;
  background: var(--ink-800);
  border: var(--line);
  border-radius: var(--radius-md);
  transition: border-color 0.28s var(--ease), background 0.28s var(--ease);
}

.page-about .ab-team__row:hover,
.page-about .ab-team__row:focus-within {
  border-color: var(--cyan-400);
}

.page-about .ab-team__head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 12px;
}

.page-about .ab-team__name {
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 19px;
  letter-spacing: -0.01em;
  color: var(--paper-050);
}

.page-about .ab-team__count {
  font-family: var(--font-mono);
  font-size: 13px;
  font-variant-numeric: tabular-nums;
  color: var(--cyan-400);
}

.page-about .ab-team__role {
  margin: 8px 0 0;
  font-size: 14.5px;
  line-height: 1.72;
  color: var(--slate-300);
}

.page-about .ab-team__tip {
  margin: 0;
  max-height: 0;
  opacity: 0;
  overflow: hidden;
  font-size: 13.5px;
  line-height: 1.72;
  color: var(--green-400);
  transition: max-height 0.28s var(--ease), opacity 0.28s var(--ease), margin-top 0.28s var(--ease);
}

.page-about .ab-team__row:hover .ab-team__tip,
.page-about .ab-team__row:focus-within .ab-team__tip {
  max-height: 6em;
  opacity: 1;
  margin-top: 8px;
}

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

/* ---------- 数据来源 ---------- */
.page-about .ab-flow {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 0;
}

.page-about .ab-flow__item {
  display: grid;
  grid-template-columns: 40px 1fr;
  gap: 14px;
  padding: 18px 0;
  border-top: var(--line);
}

.page-about .ab-flow__item:last-child {
  border-bottom: var(--line);
}

.page-about .ab-flow__num {
  padding-top: 4px;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.08em;
  color: var(--cyan-400);
}

.page-about .ab-flow__title {
  margin: 0 0 8px;
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 18px;
  line-height: 1.4;
  color: var(--paper-050);
}

.page-about .ab-flow__text {
  margin: 0;
  max-width: 58ch;
  font-size: 14.5px;
  line-height: 1.78;
  color: var(--slate-300);
}

.page-about .ab-partner {
  align-self: start;
  padding: clamp(20px, 2.6vw, 28px);
  background:
    linear-gradient(160deg, rgba(33, 230, 193, 0.14), rgba(12, 23, 48, 0) 62%),
    var(--ink-800);
  border: var(--line);
  border-radius: var(--radius-lg);
}

.page-about .ab-partner__num {
  margin: 0;
  font-family: var(--font-mono);
  font-size: clamp(32px, 4vw, 44px);
  line-height: 1.1;
  font-variant-numeric: tabular-nums;
  color: var(--paper-050);
}

.page-about .ab-partner__text {
  margin: 10px 0 0;
  font-size: 14px;
  line-height: 1.75;
  color: var(--slate-300);
}

.page-about .ab-partner__list {
  list-style: none;
  margin: 20px 0 0;
  padding: 0;
  display: grid;
  gap: 10px;
}

.page-about .ab-partner__list li {
  padding-top: 10px;
  border-top: var(--line);
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: 0.02em;
  color: var(--paper-050);
}

/* ---------- 纵向时间轴 ---------- */
.page-about .ab-tl {
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .ab-tl__item {
  position: relative;
  padding-left: 28px;
}

.page-about .ab-tl__item::before {
  content: "";
  position: absolute;
  left: 5px;
  top: 22px;
  bottom: 0;
  width: 1px;
  background: var(--ink-700);
}

.page-about .ab-tl__item:last-child::before {
  display: none;
}

.page-about .ab-tl__item::after {
  content: "";
  position: absolute;
  left: 0;
  top: 20px;
  width: 11px;
  height: 11px;
  border-radius: 50%;
  background: var(--ink-900);
  border: 2px solid var(--amber-300);
}

.page-about .ab-tl__details {
  border-bottom: var(--line);
  padding-bottom: 16px;
  margin-bottom: 18px;
}

.page-about .ab-tl__sum {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 10px;
  padding-top: 16px;
  list-style: none;
  cursor: pointer;
}

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

.page-about .ab-tl__sum::after {
  content: "展开";
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--cyan-400);
}

.page-about .ab-tl__details[open] .ab-tl__sum::after {
  content: "收起";
}

.page-about .ab-tl__stage {
  font-family: var(--font-display);
  font-weight: 600;
  font-size: clamp(18px, 2.3vw, 22px);
  line-height: 1.35;
  letter-spacing: -0.01em;
  color: var(--paper-050);
}

.page-about .ab-tl__tag {
  padding: 3px 11px;
  border: 1px solid var(--ink-700);
  border-radius: var(--radius-pill);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--amber-300);
}

.page-about .ab-tl__body {
  padding-top: 12px;
}

.page-about .ab-tl__body p {
  margin: 0;
  max-width: 56ch;
  font-size: 14.5px;
  line-height: 1.78;
  color: var(--slate-300);
}

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

/* ---------- 质量保障 ---------- */
.page-about .ab-assure {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(22px, 3vw, 34px);
}

.page-about .ab-assure__item {
  padding-top: 18px;
  border-top: 2px solid var(--ink-700);
}

.page-about .ab-assure__item:first-child {
  border-top-color: var(--cyan-400);
}

.page-about .ab-assure__title {
  margin: 0 0 10px;
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 18px;
  line-height: 1.4;
  color: var(--paper-050);
}

.page-about .ab-assure__text {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.8;
  color: var(--slate-300);
}

/* ---------- 收尾引导 ---------- */
.page-about .ab-next {
  padding-bottom: clamp(72px, 9vw, 120px);
}

.page-about .ab-next__lead {
  margin: 0 0 clamp(20px, 3vw, 32px);
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(22px, 3.2vw, 34px);
  line-height: 1.25;
  letter-spacing: -0.02em;
  color: var(--paper-050);
}

.page-about .ab-next__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: 1fr;
  gap: 1px;
  background: var(--ink-700);
  border: var(--line);
  border-radius: var(--radius-lg);
  overflow: hidden;
}

.page-about .ab-next__item {
  background: var(--ink-800);
}

.page-about .ab-next__link {
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding: 20px;
  text-decoration: none;
  transition: background 0.28s var(--ease);
}

.page-about .ab-next__link:hover,
.page-about .ab-next__link:focus-visible {
  background: var(--ink-700);
}

.page-about .ab-next__title {
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 19px;
  letter-spacing: -0.01em;
  color: var(--paper-050);
}

.page-about .ab-next__link:hover .ab-next__title,
.page-about .ab-next__link:focus-visible .ab-next__title {
  color: var(--cyan-400);
}

.page-about .ab-next__meta {
  font-size: 13.5px;
  line-height: 1.7;
  color: var(--slate-300);
}

/* ---------- 平板与桌面 ---------- */
@media (min-width: 900px) {
  .page-about .ab-hero__grid {
    grid-template-columns: 7fr 5fr;
    align-items: end;
  }

  .page-about .ab-grid-8-4 {
    grid-template-columns: 8fr 4fr;
    gap: clamp(28px, 4.4vw, 68px);
    align-items: start;
  }

  .page-about .ab-grid-7-5 {
    grid-template-columns: 7fr 5fr;
    gap: clamp(28px, 4.4vw, 68px);
    align-items: start;
  }

  .page-about .ab-scenes__item:nth-child(2) {
    margin-left: 8%;
  }

  .page-about .ab-scenes__item:nth-child(3) {
    margin-left: 16%;
  }
}

@media (min-width: 760px) {
  .page-about .ab-assure {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: clamp(26px, 3.6vw, 46px) clamp(28px, 4.4vw, 72px);
  }

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

@media (hover: none) {
  .page-about .ab-team__tip {
    max-height: 8em;
    opacity: 1;
    margin-top: 8px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .ab-team__tip,
  .page-about .ab-team__row,
  .page-about .ab-next__link {
    transition: none;
  }
}