.page-about {
  --ab-hair: 1px solid var(--ink-700);
}

.page-about .section {
  padding: clamp(34px, 6.5vw, 68px) 0;
}

.page-about .section__head {
  margin-bottom: clamp(20px, 3.4vw, 32px);
}

.page-about .section__idx {
  margin: 0 0 10px;
  font-family: var(--font-mono);
  font-size: var(--fs-xs);
  letter-spacing: 0.14em;
  color: var(--cyan);
}

.page-about .section__title {
  margin: 0 0 12px;
  font-size: var(--fs-h2);
  line-height: 1.25;
  letter-spacing: -0.01em;
  color: var(--fog);
}

.page-about .section__lead {
  margin: 0;
  max-width: 44em;
  font-size: var(--fs-body);
  line-height: 1.8;
  color: var(--slate);
}

/* 媒体容器 */
.page-about .media {
  margin: 0;
}

.page-about .media__frame {
  overflow: hidden;
  border: var(--ab-hair);
  border-radius: var(--radius-lg);
  background: var(--ink-800);
}

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

.page-about .media__caption {
  margin-top: 10px;
  font-size: var(--fs-xs);
  line-height: 1.6;
  color: var(--slate);
}

/* 首屏 */
.page-about .ab-hero {
  padding-top: clamp(20px, 4vw, 40px);
}

.page-about .ab-hero__grid {
  display: grid;
  gap: clamp(24px, 4vw, 44px);
  align-items: center;
}

.page-about .ab-hero__eyebrow {
  margin: 0 0 14px;
  font-size: var(--fs-xs);
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--signal);
}

.page-about .ab-hero__title {
  margin: 0 0 16px;
  font-size: var(--fs-h1);
  font-weight: 900;
  line-height: 1.18;
  letter-spacing: -0.02em;
  color: var(--fog);
}

.page-about .ab-hero__lead {
  margin: 0 0 22px;
  max-width: 36em;
  font-size: var(--fs-body);
  line-height: 1.85;
  color: var(--fog);
  opacity: 0.85;
}

.page-about .ab-hero__facts {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 10px;
  margin: 0 0 22px;
  padding: 0;
  list-style: none;
}

.page-about .ab-fact {
  padding: 13px 15px;
  border: var(--ab-hair);
  border-radius: var(--radius-md);
  background: var(--ink-800);
}

.page-about .ab-fact__num {
  display: block;
  font-family: var(--font-mono);
  font-size: 1.25rem;
  line-height: 1.1;
  color: var(--amber);
}

.page-about .ab-fact__label {
  display: block;
  margin-top: 6px;
  font-size: var(--fs-xs);
  line-height: 1.5;
  color: var(--slate);
}

.page-about .ab-jump {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.page-about .ab-jump__link {
  display: inline-block;
  padding: 8px 15px;
  border: var(--ab-hair);
  border-radius: var(--radius-pill);
  font-size: var(--fs-xs);
  color: var(--fog);
  text-decoration: none;
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.page-about .ab-jump__link:hover,
.page-about .ab-jump__link:focus-visible {
  color: var(--cyan);
  border-color: var(--cyan);
}

.page-about .ab-hero__media .media__frame {
  aspect-ratio: 3 / 2;
}

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

.page-about .ab-tl__item {
  position: relative;
  padding: 0 0 30px 32px;
}

.page-about .ab-tl__item::before {
  content: "";
  position: absolute;
  left: 9px;
  top: 10px;
  bottom: -6px;
  width: 1px;
  background: var(--ink-700);
}

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

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

.page-about .ab-tl__item::after {
  content: "";
  position: absolute;
  left: 3px;
  top: 6px;
  width: 13px;
  height: 13px;
  border: 2px solid var(--signal);
  border-radius: var(--radius-pill);
  background: var(--ink-900);
  box-shadow: 0 0 0 4px rgba(255, 107, 44, 0.12);
}

.page-about .ab-tl__meta {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 12px;
  margin-bottom: 8px;
}

.page-about .ab-tl__stage {
  font-family: var(--font-mono);
  font-size: var(--fs-xs);
  letter-spacing: 0.12em;
  color: var(--signal);
}

.page-about .ab-tl__span {
  font-family: var(--font-mono);
  font-size: var(--fs-xs);
  color: var(--slate);
}

.page-about .ab-tl__title {
  margin: 0 0 10px;
  font-size: var(--fs-h3);
  line-height: 1.4;
  color: var(--fog);
}

.page-about .ab-tl__text {
  margin: 0;
  max-width: 50em;
  font-size: var(--fs-body);
  line-height: 1.8;
  color: var(--slate);
}

.page-about .ab-tl__actions {
  margin: 16px 0 0;
}

.page-about .ab-tl__detail {
  margin-top: 14px;
  padding: 12px 16px;
  border: var(--ab-hair);
  border-radius: var(--radius-md);
  background: var(--ink-800);
}

.page-about .ab-tl__detail summary {
  cursor: pointer;
  list-style: none;
  font-size: var(--fs-xs);
  letter-spacing: 0.04em;
  color: var(--cyan);
}

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

.page-about .ab-tl__detail summary::before {
  content: "＋";
  margin-right: 8px;
  font-family: var(--font-mono);
  color: var(--cyan);
}

.page-about .ab-tl__detail[open] summary::before {
  content: "－";
}

.page-about .ab-tl__detail p {
  margin: 10px 0 0;
  font-size: var(--fs-xs);
  line-height: 1.75;
  color: var(--slate);
}

/* 团队分工 */
.page-about .ab-team__grid {
  display: grid;
  gap: 14px;
}

.page-about .ab-team__card {
  padding: 22px 20px;
  border: var(--ab-hair);
  border-radius: var(--radius-lg);
  background: linear-gradient(160deg, var(--ink-800), var(--ink-900));
  transition: border-color var(--dur) var(--ease), transform var(--dur) var(--ease);
}

.page-about .ab-team__card:hover,
.page-about .ab-team__card:focus-within {
  border-color: var(--cyan);
  transform: translateY(-3px);
}

.page-about .ab-team__count {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 2.25rem;
  line-height: 1;
  color: var(--signal);
}

.page-about .ab-team__unit {
  margin-left: 4px;
  font-family: var(--font-sans);
  font-size: var(--fs-xs);
  color: var(--slate);
}

.page-about .ab-team__card:nth-child(2) .ab-team__count {
  color: var(--cyan);
}

.page-about .ab-team__card:nth-child(3) .ab-team__count {
  color: var(--violet);
}

.page-about .ab-team__card:nth-child(4) .ab-team__count {
  color: var(--mint);
}

.page-about .ab-team__name {
  margin: 12px 0 8px;
  font-size: var(--fs-h3);
  color: var(--fog);
}

.page-about .ab-team__desc {
  margin: 0;
  font-size: var(--fs-body);
  line-height: 1.75;
  color: var(--slate);
}

.page-about .ab-team__hover {
  margin: 14px 0 0;
  padding-top: 12px;
  border-top: 1px dashed var(--ink-700);
  font-size: var(--fs-xs);
  line-height: 1.65;
  color: var(--cyan);
}

.page-about .ab-team__media {
  margin-top: clamp(20px, 3.5vw, 32px);
}

.page-about .ab-team__media .media__frame {
  aspect-ratio: 2 / 1;
}

/* 栏目覆盖 */
.page-about .ab-cover__grid {
  display: grid;
  gap: clamp(22px, 4vw, 40px);
  align-items: start;
}

.page-about .ab-cover__media .media__frame {
  aspect-ratio: 10 / 7;
}

.page-about .ab-cover__text {
  margin: 0 0 16px;
  font-size: var(--fs-body);
  line-height: 1.8;
  color: var(--slate);
}

.page-about .ab-cover__stats {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 10px;
  margin: 20px 0;
}

.page-about .ab-stat {
  padding: 14px 8px;
  border: var(--ab-hair);
  border-radius: var(--radius-md);
  background: var(--ink-800);
  text-align: center;
}

.page-about .ab-stat__num {
  display: block;
  font-family: var(--font-mono);
  font-size: 1.25rem;
  line-height: 1.1;
  color: var(--cyan);
}

.page-about .ab-stat__label {
  display: block;
  margin-top: 6px;
  font-size: var(--fs-xs);
  color: var(--slate);
}

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

/* 反馈流程 */
.page-about .ab-flow__list {
  margin: 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 14px;
}

.page-about .ab-flow__item {
  padding: 22px 20px;
  border: var(--ab-hair);
  border-radius: var(--radius-lg);
  background: var(--ink-800);
}

.page-about .ab-flow__no {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 34px;
  height: 34px;
  border-radius: var(--radius-pill);
  font-family: var(--font-mono);
  font-size: var(--fs-xs);
  color: var(--ink-900);
  background: var(--amber);
}

.page-about .ab-flow__item:nth-child(2) .ab-flow__no {
  background: var(--cyan);
}

.page-about .ab-flow__item:nth-child(3) .ab-flow__no {
  background: var(--violet);
}

.page-about .ab-flow__item:nth-child(4) .ab-flow__no {
  background: var(--mint);
}

.page-about .ab-flow__title {
  margin: 14px 0 8px;
  font-size: var(--fs-h3);
  color: var(--fog);
}

.page-about .ab-flow__text {
  margin: 0;
  font-size: var(--fs-body);
  line-height: 1.75;
  color: var(--slate);
}

/* 服务与响应信息板 */
.page-about .ab-board__grid {
  display: grid;
  gap: 16px;
}

.page-about .ab-board__col {
  padding: 26px 22px;
  border: var(--ab-hair);
  border-top: 3px solid var(--signal);
  border-radius: var(--radius-lg);
  background: var(--ink-800);
}

.page-about .ab-board__col:nth-child(2) {
  border-top-color: var(--cyan);
}

.page-about .ab-board__col:nth-child(3) {
  border-top-color: var(--amber);
}

.page-about .ab-board__idx {
  margin: 0 0 10px;
  font-family: var(--font-mono);
  font-size: var(--fs-xs);
  letter-spacing: 0.14em;
  color: var(--slate);
}

.page-about .ab-board__num {
  margin: 0 0 12px;
  font-family: var(--font-mono);
  font-size: clamp(1.75rem, 6vw, 2.25rem);
  line-height: 1.1;
  color: var(--fog);
}

.page-about .ab-board__text {
  margin: 0 0 18px;
  font-size: var(--fs-body);
  line-height: 1.8;
  color: var(--slate);
}

.page-about .ab-board__link {
  display: inline-block;
  font-size: var(--fs-xs);
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(44, 229, 200, 0.4);
  padding-bottom: 2px;
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.page-about .ab-board__link:hover,
.page-about .ab-board__link:focus-visible {
  color: var(--signal);
  border-color: var(--signal);
}

/* 入场节奏 */
@keyframes ab-rise {
  from {
    opacity: 0;
    transform: translateY(10px);
  }
  to {
    opacity: 1;
    transform: none;
  }
}

.page-about .ab-hero__intro,
.page-about .ab-hero__media {
  animation: ab-rise 320ms var(--ease) both;
}

.page-about .ab-hero__media {
  animation-delay: 80ms;
}

.page-about .ab-tl__item,
.page-about .ab-team__card,
.page-about .ab-flow__item,
.page-about .ab-board__col,
.page-about .ab-cover__media,
.page-about .ab-cover__body {
  animation: ab-rise 280ms var(--ease) both;
  animation-delay: calc(var(--i, 0) * 70ms);
}

@media (prefers-reduced-motion: reduce) {
  .page-about .ab-hero__intro,
  .page-about .ab-hero__media,
  .page-about .ab-tl__item,
  .page-about .ab-team__card,
  .page-about .ab-flow__item,
  .page-about .ab-board__col,
  .page-about .ab-cover__media,
  .page-about .ab-cover__body {
    animation: none;
    transition: none;
  }
}

/* 断点 */
@media (min-width: 620px) {
  .page-about .ab-hero__facts {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

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

  .page-about .ab-stat__num {
    font-size: 1.5rem;
  }

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

@media (min-width: 900px) {
  .page-about .ab-hero__grid {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, 0.95fr);
    gap: 48px;
  }

  .page-about .ab-cover__grid {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1.05fr);
    align-items: center;
  }
}

@media (min-width: 1060px) {
  .page-about .ab-team__grid {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

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

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

.page-about {
  --i: inherit;
}