.page-about {
  --about-text: #CBD6E0;
  --about-dim: #93A8BC;
  padding-bottom: clamp(48px, 7vw, 96px);
}

.page-about .about-hero {
  padding: clamp(20px, 3vw, 36px) 0 clamp(28px, 4vw, 52px);
}

.page-about .about-hero__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 28px;
  align-items: end;
}

.page-about .about-hero__eyebrow {
  margin: 0 0 14px;
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--amber);
}

.page-about .about-hero__title {
  margin: 0 0 18px;
  font-family: var(--font-display);
  font-size: clamp(2rem, 5.4vw, var(--step-4));
  font-weight: 700;
  line-height: 1.16;
  letter-spacing: -0.01em;
  color: var(--paper);
  max-width: 20ch;
}

.page-about .about-hero__lead {
  margin: 0;
  max-width: 62ch;
  font-family: var(--font-body);
  font-size: clamp(1rem, 1.5vw, 1.0625rem);
  line-height: 1.9;
  color: var(--about-text);
}

.page-about .about-hero__stats {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1px;
  margin-top: clamp(26px, 4vw, 40px);
  background: var(--ink-500);
  border: 1px solid var(--ink-500);
}

.page-about .about-stat {
  background: var(--ink-800);
  padding: 14px 14px 16px;
}

.page-about .about-stat__num {
  display: block;
  font-size: clamp(1.125rem, 3vw, var(--step-1));
  line-height: 1.2;
  color: var(--amber);
}

.page-about .about-stat__label {
  display: block;
  margin-top: 6px;
  font-size: 12.5px;
  line-height: 1.6;
  color: var(--steel);
}

.page-about .about-hero__figure {
  position: relative;
  margin: 0;
  height: 250px;
  overflow: hidden;
  background: var(--ink-800);
  border: 1px solid var(--ink-500);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - var(--cut)), calc(100% - var(--cut)) 100%, 0 100%);
}

.page-about .about-hero__figure img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
  opacity: 0.88;
}

.page-about .about-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 36px;
  margin-top: clamp(40px, 6vw, 76px);
}

/* 索引轨 */
.page-about .about-track {
  min-width: 0;
}

.page-about .about-track__title {
  display: none;
  margin: 0 0 18px;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--ink-500);
  font-size: 11px;
  letter-spacing: 0.2em;
  color: var(--dim, var(--steel));
}

.page-about .about-node {
  position: relative;
  display: block;
  flex: 0 0 208px;
  padding: 14px 16px;
  margin-right: 10px;
  background: var(--ink-800);
  border-left: 2px solid var(--amber);
  text-decoration: none;
  transition: background var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.page-about .about-node:last-child {
  margin-right: 0;
}

.page-about .about-node__year {
  display: block;
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--amber);
}

.page-about .about-node__label {
  display: block;
  margin-top: 4px;
  font-family: var(--font-display);
  font-size: 15px;
  font-weight: 600;
  line-height: 1.4;
  color: var(--paper);
}

.page-about .about-node__body {
  display: block;
  margin-top: 6px;
  font-family: var(--font-body);
  font-size: 12.5px;
  line-height: 1.7;
  color: var(--about-dim);
}

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

.page-about .about-node:focus-visible {
  outline: 2px solid var(--amber);
  outline-offset: 2px;
}

/* 正文列 */
.page-about .about-body {
  min-width: 0;
}

.page-about .about-section {
  scroll-margin-top: 110px;
  padding-bottom: clamp(34px, 5vw, 64px);
  margin-bottom: clamp(34px, 5vw, 64px);
  border-bottom: 1px solid var(--ink-700);
}

.page-about .about-section:last-of-type {
  border-bottom: 0;
  margin-bottom: 0;
  padding-bottom: 0;
}

.page-about .about-section__num {
  display: inline-block;
  margin: 0 0 14px;
  padding: 2px 9px;
  border: 1px solid var(--ink-500);
  font-size: 12px;
  letter-spacing: 0.18em;
  color: var(--amber);
}

.page-about .about-section__title {
  margin: 0 0 20px;
  font-family: var(--font-display);
  font-size: clamp(1.35rem, 3.4vw, var(--step-2));
  font-weight: 600;
  line-height: 1.3;
  color: var(--paper);
  max-width: 22ch;
}

.page-about .about-para {
  font-family: var(--font-body);
  font-size: clamp(1rem, 1.4vw, 1.0625rem);
  line-height: 1.9;
  color: var(--about-text);
  max-width: 68ch;
}

.page-about .about-para p {
  margin: 0 0 16px;
}

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

/* 岗位横条 */
.page-about .about-roles {
  display: grid;
  gap: 10px;
  margin: 28px 0 0;
}

.page-about .about-role {
  background: var(--ink-800);
  border-left: 3px solid var(--ink-500);
  transition: border-color var(--dur) var(--ease), background var(--dur) var(--ease);
}

.page-about .about-role[open] {
  border-left-color: var(--amber);
  background: var(--ink-700);
}

.page-about .about-role__head {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 6px 14px;
  padding: 14px 18px;
  cursor: pointer;
  list-style: none;
}

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

.page-about .about-role__head::marker {
  content: "";
}

.page-about .about-role__head:focus-visible {
  outline: 2px solid var(--amber);
  outline-offset: -2px;
}

.page-about .about-role__num {
  min-width: 2.4em;
  font-size: var(--step-0);
  color: var(--amber);
}

.page-about .about-role__label {
  font-family: var(--font-display);
  font-size: 1.0625rem;
  font-weight: 600;
  color: var(--paper);
}

.page-about .about-role__hint {
  margin-left: auto;
  font-size: 12.5px;
  color: var(--steel);
}

.page-about .about-role__body {
  margin: 0;
  padding: 0 18px 16px 18px;
  font-family: var(--font-body);
  font-size: 0.9375rem;
  line-height: 1.85;
  color: var(--about-text);
  max-width: 66ch;
}

/* 图 */
.page-about .about-figure {
  margin: 28px 0 0;
  max-width: 660px;
}

.page-about .about-figure img {
  display: block;
  width: 100%;
  height: auto;
  border: 1px solid var(--ink-500);
  background: var(--ink-800);
  clip-path: polygon(var(--cut) 0, 100% 0, 100% 100%, 0 100%, 0 var(--cut));
}

.page-about .about-figure__caption {
  margin-top: 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  line-height: 1.7;
  color: var(--steel);
}

/* 覆盖点阵 */
.page-about .about-matrix {
  position: relative;
  height: 176px;
  margin: 26px 0 0;
  border: 1px solid var(--ink-500);
  background-color: var(--ink-800);
  background-image: radial-gradient(circle, var(--ink-500) 1.5px, transparent 1.7px);
  background-size: 18px 18px;
  background-position: 9px 9px;
  overflow: hidden;
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - var(--cut)), calc(100% - var(--cut)) 100%, 0 100%);
}

.page-about .about-matrix::after {
  content: "";
  position: absolute;
  inset: auto 0 0 0;
  height: 52%;
  background: linear-gradient(to top, rgba(224, 166, 60, 0.22), rgba(224, 166, 60, 0));
  pointer-events: none;
}

.page-about .about-matrix__tag {
  position: absolute;
  top: 14px;
  left: 16px;
  padding: 3px 9px;
  background: var(--ink-900);
  border: 1px solid var(--amber);
  font-size: 11px;
  letter-spacing: 0.18em;
  color: var(--amber);
}

.page-about .about-matrix__note {
  margin: 10px 0 0;
  font-family: var(--font-mono);
  font-size: 12px;
  line-height: 1.7;
  color: var(--steel);
}

/* 节奏卡 */
.page-about .about-cadence {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 12px;
  margin: 26px 0;
  padding: 0;
  list-style: none;
}

.page-about .about-cadence__item {
  padding: 18px 18px 20px;
  background: var(--ink-800);
  border-top: 2px solid var(--ink-500);
}

.page-about .about-cadence__item:nth-child(1) {
  border-top-color: var(--amber);
}

.page-about .about-cadence__item:nth-child(2) {
  border-top-color: var(--sage);
}

.page-about .about-cadence__item:nth-child(3) {
  border-top-color: var(--signal);
}

.page-about .about-cadence__tag {
  display: inline-block;
  padding: 2px 8px;
  border: 1px solid var(--ink-500);
  font-size: 11px;
  letter-spacing: 0.16em;
  color: var(--amber-soft);
}

.page-about .about-cadence__title {
  margin: 12px 0 8px;
  font-family: var(--font-display);
  font-size: var(--step-0);
  font-weight: 600;
  color: var(--paper);
}

.page-about .about-cadence__text {
  margin: 0;
  font-family: var(--font-body);
  font-size: 0.9375rem;
  line-height: 1.85;
  color: var(--about-text);
}

/* 相关入口 */
.page-about .about-next {
  margin-top: clamp(48px, 7vw, 88px);
  padding-top: clamp(28px, 4vw, 44px);
  border-top: 1px dashed var(--ink-500);
}

.page-about .about-next__title {
  margin: 0 0 10px;
  font-family: var(--font-display);
  font-size: clamp(1.2rem, 3vw, var(--step-1));
  font-weight: 600;
  color: var(--paper);
}

.page-about .about-next__note {
  margin: 0 0 22px;
  font-family: var(--font-body);
  font-size: 0.9375rem;
  color: var(--steel);
}

.page-about .about-next__list {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  margin: 0;
  padding: 0;
  list-style: none;
  background: var(--ink-500);
  border: 1px solid var(--ink-500);
}

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

.page-about .about-next__item:hover {
  background: var(--ink-700);
}

.page-about .about-next__link {
  font-family: var(--font-display);
  font-size: 1rem;
  font-weight: 600;
  color: var(--amber);
  text-decoration: none;
  min-height: 0;
}

.page-about .about-next__link:hover,
.page-about .about-next__link:focus-visible {
  color: var(--amber-soft);
}

.page-about .about-next__link:focus-visible {
  outline: 2px solid var(--amber);
  outline-offset: 3px;
}

.page-about .about-next__desc {
  font-family: var(--font-body);
  font-size: 0.875rem;
  line-height: 1.7;
  color: var(--about-dim);
}

/* 入场 */
.page-about .reveal {
  opacity: 0;
  transform: translateY(14px);
}

.page-about .reveal.is-visible {
  opacity: 1;
  transform: none;
  transition: opacity 320ms var(--ease), transform 320ms var(--ease);
}

/* 中等屏 */
@media (min-width: 640px) {
  .page-about .about-hero__figure {
    height: 320px;
  }

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

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

/* 移动端：索引轨改为横向滚动 */
@media (max-width: 991px) {
  .page-about .about-track__inner {
    display: flex;
    overflow-x: auto;
    padding-bottom: 16px;
    border-bottom: 1px solid var(--ink-500);
    scrollbar-width: thin;
    -webkit-overflow-scrolling: touch;
  }

  .page-about .about-node {
    scroll-snap-align: start;
  }
}

/* 桌面端 */
@media (min-width: 992px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 1.4fr) minmax(0, 1fr);
    gap: 56px;
  }

  .page-about .about-hero__figure {
    height: 100%;
    min-height: 420px;
    max-height: 520px;
  }

  .page-about .about-layout {
    grid-template-columns: 236px minmax(0, 1fr);
    gap: 60px;
    align-items: start;
  }

  .page-about .about-track__inner {
    position: sticky;
    top: 96px;
    display: block;
    padding-bottom: 0;
    border-bottom: 0;
  }

  .page-about .about-track__title {
    display: block;
  }

  .page-about .about-node {
    flex: none;
    margin-right: 0;
    padding: 0 0 24px 26px;
    background: transparent;
    border-left: 0;
  }

  .page-about .about-node::before {
    content: "";
    position: absolute;
    left: 0;
    top: 5px;
    width: 11px;
    height: 11px;
    border-radius: 50%;
    background: var(--ink-900);
    border: 2px solid var(--sage);
    transition: border-color var(--dur) var(--ease), background var(--dur) var(--ease);
  }

  .page-about .about-node::after {
    content: "";
    position: absolute;
    left: 7px;
    top: 20px;
    bottom: 0;
    width: 1px;
    background: var(--sage);
    opacity: 0.45;
  }

  .page-about .about-node:last-child::after {
    content: none;
  }

  .page-about .about-node:hover,
  .page-about .about-node:focus-visible {
    background: transparent;
  }

  .page-about .about-node:hover::before,
  .page-about .about-node:focus-visible::before {
    border-color: var(--amber);
    background: var(--amber);
  }

  .page-about .about-node:hover .about-node__label,
  .page-about .about-node:focus-visible .about-node__label {
    color: var(--amber-soft);
  }
}

@media (min-width: 1200px) {
  .page-about .about-layout {
    grid-template-columns: 260px minmax(0, 1fr);
    gap: 72px;
  }

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

@media (prefers-reduced-motion: reduce) {
  .page-about .reveal {
    opacity: 1;
    transform: none;
  }

  .page-about .about-node,
  .page-about .about-role,
  .page-about .about-next__item {
    transition: none;
  }
}

.page-about {
  --dim: currentColor;
}