.page-about {
  position: relative;
  padding-bottom: clamp(1.5rem, 4vw, 3rem);
  overflow-x: clip;
}

.page-about .about-head {
  padding-top: .4rem;
  padding-bottom: clamp(1.8rem, 5vw, 3.4rem);
  border-bottom: 1px solid var(--paper-10);
}

.page-about .about-head .eyebrow {
  color: var(--gold);
  letter-spacing: .22em;
}

.page-about .page-head__title {
  font-family: var(--font-display);
  font-weight: 300;
  font-size: clamp(1.8rem, 6.2vw, 3.5rem);
  line-height: 1.14;
  letter-spacing: .05em;
  max-width: 21ch;
  margin: .55rem 0 1.5rem;
}

.page-about .about-head__grid {
  display: grid;
  gap: 1.6rem;
}

.page-about .about-head__grid .lead {
  margin: 0;
  max-width: 60ch;
}

.page-about .about-head__facts {
  list-style: none;
  margin: 0;
  padding: .95rem 0 0;
  border-top: 1px solid var(--gold-30);
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: .85rem 1rem;
}

.page-about .about-head__facts li {
  display: flex;
  flex-direction: column;
  gap: .18rem;
  min-width: 0;
}

.page-about .about-fact__num {
  font-family: var(--font-mono);
  font-size: 1.32rem;
  letter-spacing: .04em;
  color: var(--gold);
  line-height: 1.1;
}

.page-about .about-fact__label {
  font-size: .74rem;
  letter-spacing: .06em;
  color: var(--paper-70);
  line-height: 1.5;
}

/* ---------- 时间线 ---------- */

.page-about .about-timeline {
  padding: clamp(2.2rem, 6vw, 4.6rem) 0 clamp(2.4rem, 6vw, 4.8rem);
  background:
    linear-gradient(180deg,
      rgba(14, 42, 34, 0) 0%,
      rgba(14, 42, 34, .58) 14%,
      rgba(14, 42, 34, .58) 86%,
      rgba(14, 42, 34, 0) 100%);
}

.page-about .about-timeline__fig {
  margin: 1.6rem 0 clamp(1.8rem, 4vw, 2.8rem);
}

.page-about .timeline {
  list-style: none;
  margin: 0;
  padding: 0 0 0 1.7rem;
  position: relative;
}

.page-about .timeline::before {
  content: "";
  position: absolute;
  left: .5rem;
  top: .5rem;
  bottom: .5rem;
  width: 2px;
  border-radius: 2px;
  background: linear-gradient(180deg,
    var(--gold) 0%,
    var(--gold-30) 34%,
    rgba(216, 169, 74, .12) 100%);
}

.page-about .timeline__item {
  position: relative;
  padding: 0 0 1.5rem;
}

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

.page-about .timeline__item::before {
  content: "";
  position: absolute;
  left: calc(-1.2rem - 4px);
  top: .68rem;
  width: 9px;
  height: 9px;
  border-radius: 1px;
  background: var(--gold);
  transform: rotate(45deg);
  transition: background var(--dur) var(--ease), box-shadow var(--dur) var(--ease);
}

.page-about .timeline__item:hover::before {
  background: var(--lime);
  box-shadow: 0 0 0 5px rgba(184, 224, 74, .16);
}

.page-about .timeline__stamp {
  display: flex;
  align-items: baseline;
  gap: .7rem;
  margin-bottom: .55rem;
}

.page-about .timeline__code {
  font-family: var(--font-mono);
  font-size: 1.05rem;
  letter-spacing: .1em;
  color: var(--gold);
}

.page-about .timeline__label {
  font-size: .72rem;
  letter-spacing: .18em;
  color: var(--paper-45);
  transition: color var(--dur) var(--ease);
}

.page-about .timeline__item:hover .timeline__label {
  color: var(--lime);
}

.page-about .timeline__body {
  background: rgba(27, 29, 28, .74);
  border: 1px solid var(--paper-10);
  border-top: 2px solid var(--gold-30);
  padding: 1.1rem 1.15rem 1.2rem;
  transition: border-color var(--dur) var(--ease), background var(--dur) var(--ease);
}

.page-about .timeline__item:hover .timeline__body {
  border-color: var(--gold-45);
  border-top-color: var(--gold);
  background: rgba(27, 29, 28, .94);
}

.page-about .timeline__title {
  margin: 0 0 .55rem;
  font-family: var(--font-display);
  font-size: clamp(1.02rem, 2.4vw, 1.22rem);
  letter-spacing: .06em;
  line-height: 1.45;
  color: var(--paper);
}

.page-about .timeline__text {
  margin: 0;
  font-size: .9rem;
  line-height: 1.85;
  color: var(--paper-86);
}

.page-about .timeline__tags {
  margin: .9rem 0 0;
}

/* ---------- 栏目地图 ---------- */

.page-about .about-map {
  position: relative;
  padding: clamp(2.4rem, 6vw, 4.6rem) 0;
  background: var(--ink);
  border-bottom: 1px solid var(--gold-16);
}

.page-about .about-map::before {
  content: "";
  position: absolute;
  inset: 0 0 auto 0;
  height: 3px;
  background: linear-gradient(90deg,
    var(--gold) 0%,
    var(--blue) 38%,
    var(--magenta) 72%,
    var(--lime) 100%);
}

.page-about .map-legend {
  list-style: none;
  margin: 1.2rem 0 1.5rem;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: .55rem 1.2rem;
  font-size: .72rem;
  letter-spacing: .14em;
  color: var(--paper-70);
}

.page-about .map-legend li {
  display: flex;
  align-items: center;
  gap: .45rem;
}

.page-about .map-grid {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: .9rem;
}

.page-about .map-node {
  min-width: 0;
}

.page-about .map-node__link {
  display: flex;
  flex-direction: column;
  gap: .4rem;
  height: 100%;
  padding: 1.05rem 1.1rem 1.15rem;
  background: var(--deep);
  border: 1px solid var(--paper-10);
  border-left: 3px solid var(--blue);
  color: var(--paper);
  text-decoration: none;
  transition: border-color var(--dur) var(--ease),
              background var(--dur) var(--ease),
              transform var(--dur) var(--ease);
}

.page-about .map-node:nth-child(2) .map-node__link { border-left-color: var(--blue-lt); }
.page-about .map-node:nth-child(3) .map-node__link { border-left-color: var(--lime); }
.page-about .map-node:nth-child(4) .map-node__link { border-left-color: var(--lime); }
.page-about .map-node:nth-child(5) .map-node__link { border-left-color: var(--magenta); }
.page-about .map-node:nth-child(6) .map-node__link { border-left-color: var(--magenta); }

.page-about .map-node__link:hover,
.page-about .map-node__link:focus-visible {
  border-color: var(--gold-45);
  background: rgba(216, 169, 74, .06);
  transform: translateY(-3px);
}

.page-about .map-node__code {
  font-family: var(--font-mono);
  font-size: .7rem;
  letter-spacing: .16em;
  color: var(--gold);
}

.page-about .map-node__name {
  font-family: var(--font-display);
  font-size: 1.02rem;
  letter-spacing: .1em;
  color: var(--paper);
}

.page-about .map-node__text {
  font-size: .83rem;
  line-height: 1.75;
  color: var(--paper-70);
}

.page-about .map-node__go {
  margin-top: auto;
  padding-top: .5rem;
  font-size: .72rem;
  letter-spacing: .12em;
  color: var(--blue-lt);
  border-bottom: 1px solid transparent;
  align-self: flex-start;
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.page-about .map-node__link:hover .map-node__go,
.page-about .map-node__link:focus-visible .map-node__go {
  color: var(--gold);
  border-bottom-color: var(--gold-45);
}

/* ---------- 设备支持 ---------- */

.page-about .about-support {
  padding: clamp(2.4rem, 6vw, 4.8rem) 0;
  background: var(--paper);
  color: var(--ink);
}

.page-about .about-support .section-head h2 {
  color: var(--ink);
}

.page-about .about-support .section-head__meta {
  color: rgba(7, 18, 15, .58);
}

.page-about .support-grid {
  margin-top: 1.5rem;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  background: rgba(7, 18, 15, .18);
  border: 1px solid rgba(7, 18, 15, .18);
}

.page-about .support-card {
  background: var(--paper);
  padding: 1.25rem 1.15rem 1.35rem;
  min-width: 0;
}

.page-about .support-card__title {
  margin: 0 0 .65rem;
  padding-bottom: .55rem;
  border-bottom: 1px solid rgba(7, 18, 15, .2);
  font-family: var(--font-display);
  font-size: .96rem;
  letter-spacing: .16em;
  color: var(--ink);
}

.page-about .support-card__text {
  margin: 0;
  font-size: .86rem;
  line-height: 1.85;
  color: rgba(7, 18, 15, .76);
}

/* ---------- 维护原则 ---------- */

.page-about .about-work {
  padding: clamp(2.4rem, 6vw, 4.8rem) 0;
}

.page-about .work-grid {
  display: grid;
  gap: clamp(1.6rem, 4vw, 3rem);
}

.page-about .work-copy {
  min-width: 0;
}

.page-about .work-copy .prose {
  margin: 1rem 0 0;
  font-size: .92rem;
  line-height: 1.9;
  color: var(--paper-86);
}

.page-about .work-list {
  list-style: none;
  margin: 1.3rem 0 0;
  padding: 0;
  border-top: 1px solid var(--paper-10);
}

.page-about .work-list li {
  display: grid;
  grid-template-columns: 2.2rem minmax(0, 1fr);
  gap: .85rem;
  padding: .95rem 0;
  border-bottom: 1px solid var(--paper-10);
  font-size: .88rem;
  line-height: 1.85;
  color: var(--paper-86);
}

.page-about .work-list__num {
  font-family: var(--font-mono);
  font-size: .76rem;
  letter-spacing: .1em;
  color: var(--gold);
  padding-top: .4rem;
}

.page-about .about-work__fig {
  margin: 0;
}

/* ---------- 继续浏览 ---------- */

.page-about .about-next {
  padding: clamp(2.2rem, 6vw, 4.4rem) 0;
  background: var(--deep);
  border-top: 1px solid var(--gold-16);
}

.page-about .next-grid {
  list-style: none;
  margin: 1.4rem 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
}

.page-about .next-card {
  min-width: 0;
}

.page-about .next-card a {
  display: grid;
  grid-template-columns: 2.6rem minmax(0, 1fr);
  grid-template-areas:
    "num title"
    "num text";
  gap: .2rem .8rem;
  padding: 1.05rem .1rem;
  border-bottom: 1px solid var(--paper-10);
  text-decoration: none;
  transition: padding-left var(--dur) var(--ease), background var(--dur) var(--ease);
}

.page-about .next-card:first-child a {
  border-top: 1px solid var(--paper-10);
}

.page-about .next-card a:hover,
.page-about .next-card a:focus-visible {
  padding-left: .55rem;
  background: rgba(216, 169, 74, .06);
}

.page-about .next-card__code {
  grid-area: num;
  font-family: var(--font-mono);
  font-size: .8rem;
  letter-spacing: .1em;
  color: var(--gold);
  padding-top: .28rem;
}

.page-about .next-card__title {
  grid-area: title;
  font-family: var(--font-display);
  font-size: 1rem;
  letter-spacing: .1em;
  color: var(--paper);
  transition: color var(--dur) var(--ease);
}

.page-about .next-card a:hover .next-card__title,
.page-about .next-card a:focus-visible .next-card__title {
  color: var(--gold);
}

.page-about .next-card__text {
  grid-area: text;
  font-size: .84rem;
  line-height: 1.7;
  color: var(--paper-70);
}

/* ---------- 页尾过渡 ---------- */

.page-about .about-close {
  padding: clamp(2rem, 5vw, 4rem) 0 clamp(2.4rem, 6vw, 4.6rem);
}

.page-about .about-close__fig {
  margin: 0 0 1.4rem;
}

.page-about .about-close__line {
  margin: 0;
  max-width: 46ch;
  font-size: .94rem;
  line-height: 1.95;
  color: var(--paper-70);
}

.page-about .about-close__actions {
  margin: 1.5rem 0 0;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 1rem 1.4rem;
}

.page-about .about-close__back {
  font-size: .78rem;
  letter-spacing: .14em;
  color: var(--blue-lt);
  text-decoration: none;
  border-bottom: 1px solid var(--gold-45);
  padding-bottom: .18rem;
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.page-about .about-close__back:hover,
.page-about .about-close__back:focus-visible {
  color: var(--gold);
  border-bottom-color: var(--gold);
}

/* ---------- 响应式 ---------- */

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

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

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

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

  .page-about .next-card:nth-child(2) a {
    border-top: 1px solid var(--paper-10);
  }
}

@media (min-width: 900px) {
  .page-about .about-head__grid {
    grid-template-columns: minmax(0, 1.55fr) minmax(0, 1fr);
    gap: clamp(2rem, 5vw, 3.8rem);
    align-items: start;
  }

  .page-about .about-head__facts {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    padding-top: 1.1rem;
  }

  .page-about .timeline {
    padding-left: 2.6rem;
  }

  .page-about .timeline::before {
    left: 1.2rem;
  }

  .page-about .timeline__item {
    display: grid;
    grid-template-columns: 122px minmax(0, 1fr);
    gap: clamp(1.4rem, 3vw, 2.6rem);
    align-items: start;
    padding-bottom: 1.8rem;
  }

  .page-about .timeline__item::before {
    left: calc(-1.4rem - 4px);
  }

  .page-about .timeline__stamp {
    flex-direction: column;
    align-items: flex-start;
    gap: .3rem;
    margin: 0;
    padding-top: .45rem;
  }

  .page-about .timeline__code {
    font-size: 1.3rem;
  }

  .page-about .timeline__label {
    font-size: .7rem;
    line-height: 1.6;
  }

  .page-about .timeline__body {
    padding: 1.35rem 1.5rem 1.5rem;
  }

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

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

  .page-about .work-grid {
    grid-template-columns: minmax(0, 1.28fr) minmax(0, 1fr);
    align-items: start;
  }

  .page-about .next-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    column-gap: clamp(1.4rem, 4vw, 3rem);
  }

  .page-about .next-card:nth-child(3) a {
    border-top: 1px solid var(--paper-10);
  }
}

@media (min-width: 1100px) {
  .page-about .page-head__title {
    max-width: 24ch;
  }

  .page-about .about-head {
    padding-bottom: clamp(2.4rem, 4vw, 3.8rem);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .timeline__item::before,
  .page-about .timeline__body,
  .page-about .timeline__label,
  .page-about .map-node__link,
  .page-about .map-node__go,
  .page-about .next-card a,
  .page-about .next-card__title,
  .page-about .about-close__back {
    transition: none;
  }

  .page-about .map-node__link:hover,
  .page-about .map-node__link:focus-visible {
    transform: none;
  }
}