.page-about {
  --ab-gap: clamp(16px, 2.2vw, 28px);
  --ab-line: rgba(10, 26, 42, .13);
  background: var(--bg);
  color: var(--graphite);
  overflow-x: hidden;
}

.page-about .section {
  padding-block: clamp(40px, 6vw, 76px);
}

.page-about h1,
.page-about h2,
.page-about h3 {
  font-family: var(--font-display);
  color: var(--ink);
  letter-spacing: .02em;
  line-height: 1.22;
  margin: 0;
}

.page-about h2 {
  font-size: var(--step-3);
  font-weight: 700;
}

.page-about h3 {
  font-size: var(--step-1);
  font-weight: 700;
}

/* ---------- 首屏 ---------- */
.page-about .ab-hero {
  padding-top: clamp(14px, 2vw, 24px);
}

.page-about .ab-hero__frame {
  position: relative;
  padding: clamp(18px, 3vw, 34px);
  background:
    radial-gradient(120% 90% at 100% 0%, rgba(201, 162, 39, .16), transparent 58%),
    linear-gradient(180deg, var(--paper), #f3f6f8);
  border: 1px solid var(--line-strong);
  clip-path: polygon(0 0, calc(100% - var(--cut)) 0, 100% var(--cut), 100% 100%, var(--cut) 100%, 0 calc(100% - var(--cut)));
}

.page-about .ab-hero__frame::before,
.page-about .ab-hero__frame::after {
  content: "";
  position: absolute;
  width: 42px;
  height: 3px;
  background: var(--gold);
}

.page-about .ab-hero__frame::before {
  top: 0;
  left: clamp(18px, 3vw, 34px);
}

.page-about .ab-hero__frame::after {
  bottom: 0;
  right: clamp(18px, 3vw, 34px);
  background: var(--gold-deep);
}

.page-about .ab-hero__scale {
  height: 12px;
  margin-bottom: clamp(16px, 2.4vw, 26px);
  background:
    repeating-linear-gradient(90deg, var(--line-strong) 0 1px, transparent 1px 22px) left bottom / 100% 7px no-repeat,
    linear-gradient(90deg, var(--gold), rgba(201, 162, 39, .1) 72%) left top / 100% 2px no-repeat;
}

.page-about .ab-hero__inner {
  display: grid;
  gap: var(--ab-gap);
}

.page-about .ab-hero__main h1 {
  font-size: var(--step-4);
  font-weight: 800;
  margin: 10px 0 0;
}

.page-about .ab-hero__lead {
  margin: 16px 0 0;
  font-size: var(--step-1);
  line-height: 1.75;
  max-width: 46ch;
}

.page-about .ab-hero__meta {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin: 22px 0 0;
  padding: 0;
}

.page-about .ab-hero__meta-item {
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding: 10px 14px;
  min-width: 118px;
  background: var(--paper);
  border: 1px solid var(--line);
  border-left: 3px solid var(--gold);
}

.page-about .ab-hero__meta-k {
  font-family: var(--font-mono);
  font-size: var(--step--1);
  letter-spacing: .12em;
  color: var(--gold-deep);
  text-transform: uppercase;
}

.page-about .ab-hero__meta-v {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: var(--step-1);
  color: var(--ink);
}

.page-about .ab-hero__figure {
  margin: 0;
  position: relative;
  border: 1px solid var(--line-strong);
  background: var(--ink);
}

.page-about .ab-hero__figure img {
  display: block;
  width: 100%;
  height: 100%;
  aspect-ratio: 16 / 10;
  object-fit: cover;
  filter: saturate(.9) contrast(1.05);
}

.page-about .ab-hero__cap {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  padding: 10px 14px;
  font-family: var(--font-mono);
  font-size: var(--step--1);
  letter-spacing: .04em;
  color: var(--gold-bright);
  background: linear-gradient(180deg, rgba(10, 26, 42, 0), rgba(10, 26, 42, .9) 62%);
}

/* ---------- 起点 ---------- */
.page-about .ab-origin__grid {
  display: grid;
  gap: clamp(20px, 3vw, 40px);
}

.page-about .ab-origin__side {
  border-top: 2px solid var(--gold);
  padding-top: 14px;
}

.page-about .ab-origin__side h2 {
  margin-top: 10px;
  font-size: var(--step-3);
}

.page-about .ab-origin__kicker {
  margin: 12px 0 0;
  font-family: var(--font-mono);
  font-size: var(--step-0);
  color: var(--gold-deep);
  letter-spacing: .04em;
  line-height: 1.6;
}

.page-about .ab-origin__body p {
  margin: 0 0 16px;
  line-height: 1.8;
}

.page-about .ab-origin__body .callout {
  margin: 20px 0;
}

/* ---------- 时间轴 ---------- */
.page-about .ab-timeline {
  background:
    linear-gradient(180deg, rgba(10, 26, 42, .04), transparent 30%),
    var(--bg);
}

.page-about .ab-timeline__intro,
.page-about .ab-team__intro,
.page-about .ab-rhythm__intro {
  margin: 12px 0 0;
  max-width: 60ch;
  line-height: 1.75;
}

.page-about .ab-timeline__layout {
  display: grid;
  gap: clamp(20px, 3vw, 40px);
  margin-top: clamp(24px, 3.4vw, 40px);
}

.page-about .ab-years {
  border: 1px solid var(--line);
  background: var(--paper);
  padding: 12px 14px;
}

.page-about .ab-years__title {
  margin: 0 0 10px;
}

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

.page-about .ab-years__link {
  display: inline-block;
  padding: 5px 10px;
  font-family: var(--font-mono);
  font-size: var(--step-0);
  letter-spacing: .08em;
  color: var(--ink-2);
  text-decoration: none;
  border: 1px solid var(--line);
  border-bottom: 2px solid var(--gold);
  transition: background var(--dur) var(--ease), color var(--dur) var(--ease), transform var(--dur) var(--ease);
}

.page-about .ab-years__link:hover,
.page-about .ab-years__link:focus-visible {
  background: var(--ink);
  color: var(--gold-bright);
  transform: translateY(-2px);
}

.page-about .ab-years__link:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 2px;
}

.page-about .ab-track {
  list-style: none;
  margin: 0;
  padding: 0 0 0 22px;
  border-left: 1px dashed var(--line-strong);
  display: grid;
  gap: clamp(16px, 2.4vw, 26px);
}

.page-about .ab-node {
  position: relative;
  background: var(--paper);
  border: 1px solid var(--line);
  padding: 16px 18px 18px;
  clip-path: polygon(0 0, calc(100% - 14px) 0, 100% 14px, 100% 100%, 0 100%);
  transition: border-color var(--dur) var(--ease), transform var(--dur) var(--ease), box-shadow var(--dur) var(--ease);
}

.page-about .ab-node::before {
  content: "";
  position: absolute;
  left: -30px;
  top: 22px;
  width: 9px;
  height: 9px;
  background: var(--amber);
  box-shadow: 0 0 0 3px var(--bg);
  transform: rotate(45deg);
}

.page-about .ab-node:hover {
  transform: translateY(-3px);
  border-color: var(--gold);
  box-shadow: 0 10px 24px rgba(10, 26, 42, .08);
}

.page-about .ab-node__top {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px;
}

.page-about .ab-node__year {
  font-family: var(--font-mono);
  font-size: var(--step-2);
  font-weight: 700;
  letter-spacing: .06em;
  color: var(--gold-deep);
}

.page-about .ab-node__title {
  margin: 10px 0 8px;
}

.page-about .ab-node__text {
  margin: 0;
  line-height: 1.78;
}

.page-about .ab-node__note {
  margin: 12px 0 0;
  padding-left: 12px;
  border-left: 2px solid var(--gold);
  font-size: var(--step-0);
  line-height: 1.7;
  color: var(--ink-2);
}

.page-about .ab-track__figure {
  list-style: none;
}

.page-about .ab-timeline__figure {
  margin: 0;
  border: 1px solid var(--line-strong);
  background: var(--ink);
}

.page-about .ab-timeline__figure img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 4 / 3;
  object-fit: cover;
}

.page-about .ab-timeline__figure .media-frame__caption {
  padding: 10px 14px;
  background: var(--ink-2);
  color: var(--on-ink-text);
  font-family: var(--font-mono);
  font-size: var(--step--1);
  letter-spacing: .04em;
}

/* ---------- 团队 ---------- */
.page-about .ab-team__grid {
  display: grid;
  gap: 14px;
  margin-top: clamp(22px, 3vw, 36px);
}

.page-about .ab-team__cell {
  position: relative;
  padding: 20px 18px 22px;
  background: var(--paper);
  border: 1px solid var(--line);
  border-top: 3px solid var(--ink-2);
  clip-path: polygon(0 0, calc(100% - 16px) 0, 100% 16px, 100% 100%, 0 100%);
  transition: transform var(--dur) var(--ease), border-color var(--dur) var(--ease), background var(--dur) var(--ease);
}

.page-about .ab-team__cell:hover,
.page-about .ab-team__cell:focus-visible {
  transform: translateY(-3px);
  border-color: var(--gold);
  background: #fff;
}

.page-about .ab-team__cell:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 3px;
}

.page-about .ab-team__cell--edit {
  border-top-color: var(--gold);
}

.page-about .ab-team__cell--test {
  border-top-color: var(--cyan);
}

.page-about .ab-team__cell--support {
  border-top-color: var(--ok);
}

.page-about .ab-team__cell--prod {
  border-top-color: var(--amber);
}

.page-about .ab-team__count {
  margin: 0;
  font-family: var(--font-mono);
  font-size: var(--step-4);
  font-weight: 700;
  line-height: 1;
  letter-spacing: .04em;
  color: var(--ink);
  opacity: .16;
}

.page-about .ab-team__role {
  margin: -6px 0 10px;
}

.page-about .ab-team__text {
  margin: 0;
  line-height: 1.78;
  font-size: var(--step-0);
}

/* ---------- 覆盖 ---------- */
.page-about .ab-cover {
  background: linear-gradient(180deg, rgba(19, 45, 69, .06), transparent 70%);
}

.page-about .ab-cover__grid {
  display: grid;
  gap: clamp(20px, 3vw, 36px);
  margin-top: clamp(20px, 3vw, 32px);
  align-items: start;
}

.page-about .ab-cover__body p {
  margin: 0 0 16px;
  line-height: 1.8;
}

.page-about .ab-cover__figure {
  margin: 0;
  border: 1px solid var(--line-strong);
  background: var(--ink-2);
}

.page-about .ab-cover__figure img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 5 / 3;
  object-fit: cover;
}

.page-about .ab-cover__figure .media-frame__caption {
  padding: 10px 14px;
  color: var(--on-ink-text);
  font-family: var(--font-mono);
  font-size: var(--step--1);
  letter-spacing: .04em;
}

.page-about .ab-stats {
  list-style: none;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: clamp(24px, 3vw, 36px) 0 0;
  padding: 0;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .ab-stat {
  background: var(--paper);
  padding: 18px 16px;
}

.page-about .ab-stat__num {
  display: block;
  font-family: var(--font-mono);
  font-size: var(--step-3);
  font-weight: 700;
  color: var(--gold-deep);
  letter-spacing: .02em;
}

.page-about .ab-stat__label {
  display: block;
  margin-top: 6px;
  font-size: var(--step-0);
  color: var(--ink-2);
}

/* ---------- 节奏 ---------- */
.page-about .ab-rhythm__list {
  list-style: none;
  display: grid;
  gap: 14px;
  margin: clamp(22px, 3vw, 34px) 0 0;
  padding: 0;
  counter-reset: ab-rhythm;
}

.page-about .ab-rhythm__item {
  position: relative;
  padding: 18px 18px 20px;
  background: var(--paper);
  border: 1px solid var(--line);
  border-left: 3px solid var(--gold);
}

.page-about .ab-rhythm__cycle {
  margin: 0 0 8px;
  font-family: var(--font-mono);
  font-size: var(--step--1);
  letter-spacing: .16em;
  color: var(--gold-deep);
}

.page-about .ab-rhythm__title {
  margin: 0 0 8px;
  font-size: var(--step-1);
}

.page-about .ab-rhythm__text {
  margin: 0;
  font-size: var(--step-0);
  line-height: 1.75;
}

/* ---------- 收束 ---------- */
.page-about .ab-cta__panel {
  padding: clamp(22px, 3.4vw, 42px);
  border: 1px solid var(--on-ink-line);
}

.page-about .ab-cta__panel .eyebrow {
  color: var(--gold-bright);
}

.page-about .ab-cta__panel h2 {
  color: #fff;
  margin-top: 10px;
}

.page-about .ab-cta__grid {
  display: grid;
  gap: clamp(20px, 3vw, 36px);
}

.page-about .ab-cta__lead {
  margin: 14px 0 0;
  color: var(--on-ink-text);
  line-height: 1.8;
  max-width: 52ch;
}

.page-about .ab-cta__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 22px;
}

.page-about .ab-cta__side {
  border-top: 1px solid var(--on-ink-line);
  padding-top: 18px;
}

.page-about .ab-cta__row {
  display: flex;
  flex-direction: column;
  gap: 3px;
  padding: 10px 0;
  border-bottom: 1px dashed var(--on-ink-line);
}

.page-about .ab-cta__k {
  font-family: var(--font-mono);
  font-size: var(--step--1);
  letter-spacing: .14em;
  color: var(--gold-bright);
}

.page-about .ab-cta__v {
  color: #fff;
  font-size: var(--step-0);
  line-height: 1.6;
  word-break: break-word;
}

.page-about .ab-cta__note {
  margin: 14px 0 0;
  font-size: var(--step--1);
  line-height: 1.7;
  color: var(--on-ink-muted);
}

/* ---------- 断点 ---------- */
@media (min-width: 700px) {
  .page-about .ab-hero__inner {
    grid-template-columns: 1.15fr .85fr;
    align-items: center;
  }

  .page-about .ab-hero__figure img {
    aspect-ratio: 4 / 5;
  }

  .page-about .ab-origin__grid {
    grid-template-columns: minmax(0, 4fr) minmax(0, 8fr);
    align-items: start;
  }

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

  .page-about .ab-cover__grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
  }

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

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

  .page-about .ab-cta__grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
  }

  .page-about .ab-cta__side {
    border-top: none;
    border-left: 1px solid var(--on-ink-line);
    padding-top: 0;
    padding-left: clamp(18px, 2.4vw, 28px);
  }
}

@media (min-width: 960px) {
  .page-about .ab-hero__main h1 {
    font-size: var(--step-5);
  }

  .page-about .ab-timeline__layout {
    grid-template-columns: 168px minmax(0, 1fr);
    align-items: start;
  }

  .page-about .ab-years {
    position: sticky;
    top: 104px;
    padding: 16px;
  }

  .page-about .ab-years__list {
    flex-direction: column;
    gap: 6px;
  }

  .page-about .ab-years__link {
    display: block;
    width: 100%;
    text-align: left;
  }

  .page-about .ab-team__grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    grid-template-areas:
      "edit edit test"
      "edit edit support"
      "prod prod support";
  }

  .page-about .ab-team__cell--edit {
    grid-area: edit;
  }

  .page-about .ab-team__cell--test {
    grid-area: test;
  }

  .page-about .ab-team__cell--support {
    grid-area: support;
  }

  .page-about .ab-team__cell--prod {
    grid-area: prod;
  }

  .page-about .ab-team__cell--edit .ab-team__count {
    font-size: var(--step-5);
  }

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

@media (prefers-reduced-motion: reduce) {
  .page-about .ab-node,
  .page-about .ab-team__cell,
  .page-about .ab-years__link {
    transition: none;
  }

  .page-about .ab-node:hover,
  .page-about .ab-team__cell:hover,
  .page-about .ab-years__link:hover {
    transform: none;
  }
}