/* ===== 发展历程页 · 作用域 .page-about ===== */
.page-about {
  --ab-axis-w: 140px;
  --ab-pad: clamp(20px, 3.2vw, 40px);
  background: var(--paper-050);
  color: var(--text-900);
  font-family: var(--font-body);
}

/* --- 面包屑条 --- */
.page-about .ab-topline {
  background: var(--paper-050);
  border-bottom: 1px solid var(--line-200);
  padding: 12px 0;
}

/* --- 首屏 --- */
.page-about .ab-hero {
  position: relative;
  overflow: hidden;
  background: var(--ink-900);
  color: var(--paper-000);
  padding: clamp(36px, 6vw, 80px) 0 clamp(52px, 8vw, 104px);
  border-bottom: 4px solid var(--signal-500);
}

.page-about .ab-hero__cut {
  position: absolute;
  top: -12%;
  right: -6%;
  width: 46%;
  height: 132%;
  background: var(--ink-700);
  clip-path: polygon(30% 0, 100% 0, 100% 100%, 0 100%);
  pointer-events: none;
}

.page-about .ab-hero__stamp {
  position: absolute;
  right: clamp(16px, 5vw, 72px);
  bottom: clamp(14px, 3vw, 36px);
  z-index: 3;
  font-family: var(--font-mono);
  font-size: clamp(2rem, 7vw, 4.6rem);
  font-weight: 700;
  letter-spacing: .06em;
  line-height: 1;
  color: transparent;
  -webkit-text-stroke: 1px rgba(34, 216, 203, .5);
  pointer-events: none;
}

.page-about .ab-hero__inner {
  position: relative;
  z-index: 2;
}

.page-about .ab-hero__kicker {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  margin: 0 0 20px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .16em;
  text-transform: uppercase;
  color: var(--cyan-400);
}

.page-about .ab-hero__kicker::before {
  content: "";
  width: 8px;
  height: 8px;
  background: var(--cyan-400);
  flex: none;
}

.page-about .ab-hero__title {
  margin: 0 0 22px;
  max-width: 15em;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(2rem, 5.6vw, 4.2rem);
  line-height: 1.06;
  letter-spacing: -.018em;
  color: var(--paper-000);
}

.page-about .ab-hero__hl {
  color: var(--signal-500);
  font-family: var(--font-mono);
  letter-spacing: .01em;
  padding: 0 .06em;
}

.page-about .ab-hero__lede {
  margin: 0 0 28px;
  max-width: 46em;
  font-size: clamp(1rem, 1.5vw, 1.125rem);
  line-height: 1.76;
  color: var(--paper-050);
  opacity: .9;
}

.page-about .ab-hero__meta {
  display: flex;
  flex-wrap: wrap;
  gap: 10px 26px;
  margin: 0;
  padding: 0;
  list-style: none;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .08em;
  color: var(--line-400);
}

.page-about .ab-hero__meta li {
  position: relative;
  padding-left: 14px;
}

.page-about .ab-hero__meta li::before {
  content: "";
  position: absolute;
  left: 0;
  top: .55em;
  width: 6px;
  height: 6px;
  background: var(--signal-500);
}

/* --- 规模数据带 --- */
.page-about .ab-band {
  background: var(--ink-700);
  color: var(--paper-000);
}

.page-about .ab-band__inner {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: clamp(28px, 4vw, 44px) 0;
  background: var(--ink-600);
  border: 1px solid var(--ink-600);
}

.page-about .ab-band__cell {
  background: var(--ink-700);
  padding: clamp(18px, 2.6vw, 28px) clamp(14px, 2.4vw, 26px);
}

.page-about .ab-band__num {
  display: block;
  margin-bottom: 10px;
  font-family: var(--font-mono);
  font-size: clamp(1.7rem, 3.6vw, 2.6rem);
  font-weight: 700;
  line-height: 1;
  letter-spacing: .02em;
  color: var(--cyan-400);
}

.page-about .ab-band__num--signal {
  color: var(--signal-500);
}

.page-about .ab-band__label {
  display: block;
  font-size: 13px;
  line-height: 1.6;
  letter-spacing: .03em;
  color: var(--line-400);
}

/* --- 时间线骨架 --- */
.page-about .ab-timeline {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 0;
  padding-top: clamp(36px, 6vw, 72px);
  padding-bottom: clamp(48px, 7vw, 96px);
}

.page-about .ab-axis {
  display: none;
}

.page-about .ab-stages {
  display: flex;
  flex-direction: column;
  gap: clamp(28px, 4vw, 52px);
  min-width: 0;
}

/* --- 阶段面板 --- */
.page-about .ab-stage {
  position: relative;
  min-width: 0;
  padding: var(--ab-pad);
  background: var(--paper-000);
  border: 1px solid var(--line-200);
  box-shadow: var(--shadow-1);
  scroll-margin-top: 148px;
}

.page-about .ab-stage::after {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 44px;
  height: 4px;
  background: var(--signal-500);
}

.page-about .ab-stage__head {
  display: flex;
  align-items: flex-start;
  gap: clamp(14px, 2.2vw, 26px);
  padding-bottom: 16px;
  margin-bottom: clamp(18px, 2.6vw, 28px);
  border-bottom: 1px solid var(--line-200);
}

.page-about .ab-stage__no {
  flex: none;
  font-family: var(--font-mono);
  font-size: clamp(2rem, 4.4vw, 3.1rem);
  font-weight: 700;
  line-height: .88;
  letter-spacing: .02em;
  color: var(--signal-500);
}

.page-about .ab-stage__head-text {
  min-width: 0;
}

.page-about .ab-stage__year {
  margin: 0 0 6px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .14em;
  text-transform: uppercase;
  color: var(--line-400);
}

.page-about .ab-stage__title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(1.25rem, 2.4vw, 1.9rem);
  line-height: 1.22;
  letter-spacing: -.012em;
  color: var(--ink-900);
}

.page-about .ab-stage__body p,
.page-about .ab-stage p {
  margin: 0 0 16px;
  max-width: 46em;
  font-size: 16.5px;
  line-height: 1.78;
  color: var(--text-700);
}

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

.page-about .ab-stage a {
  color: var(--signal-700);
  text-decoration: underline;
  text-underline-offset: 3px;
  text-decoration-thickness: 1px;
}

.page-about .ab-stage a:hover {
  color: var(--signal-500);
}

.page-about .ab-stage a:focus-visible {
  outline: 2px solid var(--signal-500);
  outline-offset: 2px;
}

.page-about .ab-stage__lede {
  margin: 0 0 clamp(18px, 2.6vw, 28px);
  max-width: 44em;
  padding-left: 16px;
  border-left: 3px solid var(--cyan-400);
  font-size: clamp(1rem, 1.6vw, 1.1rem);
  line-height: 1.74;
  color: var(--ink-900);
}

.page-about .ab-stage__list {
  margin: 0 0 16px;
  padding: 0;
  list-style: none;
}

.page-about .ab-stage__list li {
  position: relative;
  margin-bottom: 12px;
  padding-left: 22px;
  font-size: 16px;
  line-height: 1.72;
  color: var(--text-700);
}

.page-about .ab-stage__list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: .78em;
  width: 10px;
  height: 1px;
  background: var(--signal-500);
}

.page-about .ab-stage__list li b {
  color: var(--ink-900);
  font-weight: 700;
}

/* --- 双栏与图 --- */
.page-about .ab-cols {
  min-width: 0;
}

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

.page-about .ab-figure img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  object-fit: cover;
  border: 1px solid var(--line-200);
  background: var(--paper-050);
}

.page-about .ab-figure figcaption {
  margin-top: 10px;
  font-size: 13px;
  line-height: 1.65;
  color: var(--line-400);
}

.page-about .ab-figure--wide {
  margin-top: clamp(22px, 3.4vw, 36px);
}

/* --- 折线图 --- */
.page-about .ab-curve {
  margin: 0 0 clamp(20px, 3vw, 32px);
  padding: clamp(16px, 2.4vw, 24px) clamp(14px, 2.4vw, 24px) 4px;
  background: var(--paper-050);
  border: 1px solid var(--line-200);
}

.page-about .ab-curve__cap {
  margin: 0 0 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .12em;
  color: var(--line-400);
}

.page-about .ab-curve__svg {
  display: block;
  width: 100%;
  max-width: 720px;
  height: auto;
}

.page-about .ab-curve__labels {
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: .04em;
  fill: var(--text-700);
}

/* --- 标签页 --- */
.page-about .ab-tabs {
  position: relative;
  margin-bottom: clamp(8px, 1.5vw, 16px);
}

.page-about .ab-tabs .tabs__list {
  position: relative;
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  padding: 0;
  margin: 0 0 20px;
  border-bottom: 1px solid var(--line-200);
}

.page-about .ab-tabs .tabs__tab {
  appearance: none;
  -webkit-appearance: none;
  cursor: pointer;
  padding: 10px 16px;
  border: 1px solid var(--line-200);
  border-bottom: 0;
  border-radius: var(--radius) var(--radius) 0 0;
  background: var(--paper-050);
  color: var(--text-700);
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: .06em;
}

.page-about .ab-tabs .tabs__tab[aria-selected="true"] {
  background: var(--ink-900);
  border-color: var(--ink-900);
  color: var(--paper-000);
  font-weight: 700;
}

.page-about .ab-tabs .tabs__tab:focus-visible {
  outline: 2px solid var(--signal-500);
  outline-offset: 2px;
}

.page-about .ab-tabs .tabs__ink {
  position: absolute;
  bottom: -1px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--signal-500);
  transition: transform .22s var(--ease), width .22s var(--ease);
}

.page-about .ab-tabs .tabs__panel {
  outline: none;
}

.page-about .ab-tabs .tabs__panel[hidden] {
  display: none !important;
}

.page-about .ab-tabs .tabs__panel:focus-visible {
  outline: 2px solid var(--signal-500);
  outline-offset: 4px;
}

.page-about .ab-tabnum {
  margin: 0 0 10px;
  font-family: var(--font-mono);
  font-size: clamp(1.6rem, 3vw, 2.2rem);
  font-weight: 700;
  line-height: 1;
  color: var(--cyan-700);
}

/* --- 手风琴 --- */
.page-about .ab-accordion {
  border-top: 1px solid var(--line-200);
}

.page-about .ab-accordion .accordion__item {
  border-bottom: 1px solid var(--line-200);
}

.page-about .ab-accordion .accordion__trigger {
  display: flex;
  align-items: baseline;
  gap: 14px;
  width: 100%;
  padding: 16px 0;
  border: 0;
  background: none;
  text-align: left;
  cursor: pointer;
  font-family: inherit;
  color: var(--ink-900);
}

.page-about .ab-accordion .accordion__trigger:focus-visible {
  outline: 2px solid var(--signal-500);
  outline-offset: 2px;
}

.page-about .ab-acc__no {
  flex: none;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .1em;
  color: var(--signal-500);
}

.page-about .ab-acc__title {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(1rem, 1.6vw, 1.15rem);
  line-height: 1.4;
}

.page-about .ab-accordion .accordion__panel {
  padding: 0 0 18px 34px;
}

.page-about .ab-accordion .accordion__panel p {
  margin: 0;
  max-width: 44em;
  font-size: 16px;
  line-height: 1.74;
  color: var(--text-700);
}

/* --- 事实条目 --- */
.page-about .ab-facts {
  margin: 0;
  border-top: 1px solid var(--line-200);
}

.page-about .ab-facts__row {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 6px 20px;
  padding: 18px 0;
  border-bottom: 1px solid var(--line-200);
}

.page-about .ab-facts__key {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .12em;
  text-transform: uppercase;
  color: var(--signal-700);
  padding-top: .25em;
}

.page-about .ab-facts__val {
  margin: 0;
  max-width: 46em;
  font-size: 16px;
  line-height: 1.76;
  color: var(--text-700);
}

/* --- 路线图 --- */
.page-about .ab-road {
  margin: 0;
  padding: 0;
  list-style: none;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  background: var(--line-200);
  border: 1px solid var(--line-200);
}

.page-about .ab-road__item {
  background: var(--paper-000);
  padding: clamp(18px, 2.6vw, 26px);
}

.page-about .ab-road__no {
  display: block;
  margin-bottom: 10px;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: .14em;
  color: var(--violet-500);
}

.page-about .ab-road__title {
  margin: 0 0 8px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(1.05rem, 1.8vw, 1.25rem);
  line-height: 1.35;
  color: var(--ink-900);
}

.page-about .ab-road__item p {
  margin: 0;
  font-size: 15.5px;
  line-height: 1.74;
  color: var(--text-700);
}

.page-about .ab-road__cta {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: clamp(20px, 3vw, 30px);
}

/* --- 媒体查询 --- */
@media (min-width: 560px) {
  .page-about .ab-band__inner {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .ab-facts__row {
    grid-template-columns: 128px minmax(0, 1fr);
    gap: 0 24px;
  }
}

@media (min-width: 820px) {
  .page-about .ab-cols {
    display: grid;
    grid-template-columns: minmax(0, 1.1fr) minmax(0, .9fr);
    gap: clamp(24px, 3.4vw, 44px);
    align-items: start;
  }

  .page-about .ab-cols--aside-left {
    grid-template-columns: minmax(0, .9fr) minmax(0, 1.1fr);
  }

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

@media (min-width: 900px) {
  .page-about .ab-timeline {
    grid-template-columns: var(--ab-axis-w) minmax(0, 1fr);
    gap: 0 clamp(28px, 4vw, 64px);
    align-items: start;
  }

  .page-about .ab-axis {
    display: block;
    position: sticky;
    top: 132px;
    align-self: start;
  }

  .page-about .ab-axis__rail {
    position: relative;
    display: flex;
    flex-direction: column;
    gap: 26px;
    margin: 0;
    padding: 4px 0 4px 22px;
    border-left: 1px solid var(--line-200);
  }

  .page-about .ab-axis__link {
    position: relative;
    display: block;
    text-decoration: none;
    color: var(--text-700);
  }

  .page-about .ab-axis__link::before {
    content: "";
    position: absolute;
    left: -26px;
    top: 4px;
    width: 9px;
    height: 9px;
    background: var(--paper-050);
    border: 1px solid var(--line-400);
    transition: background .18s var(--ease), border-color .18s var(--ease);
  }

  .page-about .ab-axis__link:hover::before,
  .page-about .ab-axis__link:focus-visible::before,
  .page-about .ab-axis__link[aria-current="true"]::before {
    background: var(--signal-500);
    border-color: var(--signal-500);
  }

  .page-about .ab-axis__link:focus-visible {
    outline: 2px solid var(--signal-500);
    outline-offset: 3px;
  }

  .page-about .ab-axis__year {
    display: block;
    font-family: var(--font-mono);
    font-size: 15px;
    font-weight: 700;
    letter-spacing: .04em;
    line-height: 1.2;
    color: var(--ink-900);
  }

  .page-about .ab-axis__link[aria-current="true"] .ab-axis__year {
    color: var(--signal-500);
  }

  .page-about .ab-axis__tag {
    display: block;
    margin-top: 2px;
    font-size: 11px;
    letter-spacing: .1em;
    color: var(--line-400);
  }

  .page-about .ab-stage {
    margin-right: 48px;
  }

  .page-about .ab-stage:nth-child(2) {
    margin-left: 24px;
    margin-right: 24px;
  }

  .page-about .ab-stage:nth-child(4) {
    margin-left: 24px;
    margin-right: 24px;
  }

  .page-about .ab-stage:nth-child(6) {
    margin-left: 48px;
    margin-right: 0;
  }
}

@media (max-width: 900px) {
  .page-about .ab-hero__stamp {
    display: none;
  }

  .page-about .ab-hero__cut {
    width: 62%;
    right: -18%;
    opacity: .7;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .ab-tabs .tabs__ink,
  .page-about .ab-axis__link::before {
    transition: none;
  }
}
<<<END>>>