.page-about {
  --about-rail: 108px;
  --about-gap: clamp(40px, 7vw, 88px);
}

.page-about .crumbs {
  padding-top: clamp(18px, 3vw, 28px);
}

/* ---------- 首屏 ---------- */
.page-about .about-mast {
  padding-top: clamp(34px, 7vw, 72px);
  padding-bottom: clamp(40px, 6vw, 72px);
  position: relative;
  overflow: hidden;
}

.page-about .about-mast::before {
  content: "";
  position: absolute;
  left: 50%;
  top: 12%;
  width: min(760px, 120vw);
  height: min(760px, 120vw);
  transform: translateX(-38%);
  border: 1px solid var(--line-orbit);
  border-radius: 50%;
  opacity: 0.45;
  pointer-events: none;
}

.page-about .about-mast::after {
  content: "";
  position: absolute;
  left: 50%;
  top: calc(12% + 90px);
  width: min(580px, 92vw);
  height: min(580px, 92vw);
  transform: translateX(-30%);
  border: 1px dashed var(--line-orbit);
  border-radius: 50%;
  opacity: 0.35;
  pointer-events: none;
}

.page-about .about-mast__inner {
  position: relative;
  z-index: 1;
}

.page-about .about-mast__title {
  margin: 18px 0 24px;
  font-size: clamp(2rem, 6.6vw, 4.2rem);
  font-weight: 200;
  letter-spacing: 0.06em;
  line-height: 1.2;
  color: var(--star);
  max-width: 22ch;
}

.page-about .about-lede {
  margin: 0;
  max-width: 62ch;
  font-size: clamp(15px, 1.5vw, 17px);
  line-height: 1.95;
  color: var(--dust);
}

.page-about .about-stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: clamp(32px, 5vw, 52px) 0 0;
  padding: 1px;
  list-style: none;
  background: var(--line-orbit);
  border: 1px solid var(--line-orbit);
  max-width: 900px;
}

.page-about .about-stats li {
  background: var(--ink-night);
  padding: 18px 16px;
}

.page-about .about-stats__num {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(22px, 3.2vw, 32px);
  font-weight: 400;
  letter-spacing: 0.02em;
  color: var(--pulse);
  line-height: 1.1;
}

.page-about .about-stats__key {
  display: block;
  margin-top: 8px;
  font-size: 12.5px;
  letter-spacing: 0.08em;
  color: var(--dust);
}

/* ---------- 章节骨架 ---------- */
.page-about .about-chapter {
  padding-block: var(--about-gap);
  border-top: 1px solid var(--line-orbit);
}

.page-about .about-chapter__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 20px;
}

.page-about .about-rail {
  display: flex;
  align-items: baseline;
  gap: 12px;
}

.page-about .about-rail__idx {
  font-family: var(--font-mono);
  font-size: clamp(26px, 5vw, 34px);
  font-weight: 400;
  color: var(--nebula);
  letter-spacing: 0.04em;
  line-height: 1;
}

.page-about .about-rail__label {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.24em;
  color: var(--dust);
  text-transform: uppercase;
}

.page-about .about-h2 {
  margin: 0 0 22px;
  font-size: clamp(1.5rem, 3.6vw, 2.3rem);
  font-weight: 250;
  letter-spacing: 0.05em;
  line-height: 1.32;
  color: var(--star);
  max-width: 24ch;
}

.page-about .about-copy {
  margin: 0 0 20px;
  font-size: 16px;
  line-height: 1.9;
  color: var(--dust);
  max-width: 34em;
}

.page-about .about-copy--tight {
  margin-top: 28px;
  margin-bottom: 0;
}

.page-about .about-cols {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 18px 40px;
  margin-bottom: clamp(28px, 4vw, 44px);
}

.page-about .about-cols p {
  margin: 0;
  font-size: 16px;
  line-height: 1.9;
  color: var(--dust);
}

/* ---------- 时间线 ---------- */
.page-about .tl {
  position: relative;
  list-style: none;
  margin: 0 0 clamp(30px, 5vw, 48px);
  padding: 0 0 0 34px;
}

.page-about .tl::before {
  content: "";
  position: absolute;
  left: 7px;
  top: 12px;
  bottom: 12px;
  width: 1px;
  background: linear-gradient(180deg, var(--nebula) 0%, var(--line-orbit) 60%, transparent 100%);
}

.page-about .tl__item {
  position: relative;
  padding-bottom: 20px;
}

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

.page-about .tl__dot {
  position: absolute;
  left: -34px;
  top: 9px;
  width: 15px;
  height: 15px;
  border-radius: 50%;
  border: 2px solid var(--nebula);
  background: var(--ink-deep);
  transition: background var(--fast) var(--ease), border-color var(--fast) var(--ease), transform var(--fast) var(--ease);
}

.page-about .tl__item:hover .tl__dot {
  background: var(--pulse);
  border-color: var(--pulse);
  transform: scale(1.18);
}

.page-about .tl__card {
  border: 1px solid var(--line-orbit);
  background: var(--ink-night);
  padding: 16px 18px;
  transition: border-color var(--fast) var(--ease), transform var(--fast) var(--ease), box-shadow var(--fast) var(--ease);
}

.page-about .tl__card:hover,
.page-about .tl__card:focus-within,
.page-about .tl__card:focus {
  border-color: var(--nebula);
  transform: translate(-3px, -3px);
  box-shadow: inset 0 0 0 2px var(--nebula), 6px 6px 0 var(--shadow-deep);
  outline: none;
}

.page-about .tl__stage {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.2em;
  color: var(--pulse);
  background: rgba(57, 230, 208, 0.08);
  border: 1px solid rgba(57, 230, 208, 0.28);
  padding: 2px 8px;
  margin-bottom: 10px;
}

.page-about .tl__title {
  margin: 0 0 6px;
  font-size: 17px;
  font-weight: 400;
  letter-spacing: 0.03em;
  color: var(--star);
  line-height: 1.5;
}

.page-about .tl__sum {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.8;
  color: var(--dust);
}

.page-about .tl__more {
  margin: 0;
  max-height: none;
  opacity: 1;
  overflow: hidden;
  font-size: 14px;
  line-height: 1.85;
  color: var(--dust);
  transition: max-height 200ms var(--ease), opacity 180ms var(--ease), margin-top 200ms var(--ease);
}

/* ---------- 图片容器微调 ---------- */
.page-about .about-figure {
  margin: clamp(28px, 4vw, 44px) 0 0;
}

.page-about .about-figure--orbit {
  margin-bottom: clamp(28px, 4vw, 44px);
}

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

.page-about .figure__frame {
  overflow: hidden;
}

/* ---------- 索引域列表 ---------- */
.page-about .domain-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 10px;
}

.page-about .domain {
  display: grid;
  grid-template-columns: 52px minmax(0, 1fr);
  gap: 14px;
  align-items: start;
  border: 1px solid var(--line-orbit);
  background: var(--ink-night);
  padding: 16px;
  transition: border-color var(--fast) var(--ease), background var(--fast) var(--ease), transform var(--fast) var(--ease);
}

.page-about .domain:hover,
.page-about .domain:focus-within {
  border-color: var(--nebula);
  background: #0E1630;
  transform: translateX(3px);
}

.page-about .domain__code {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 52px;
  height: 52px;
  font-family: var(--font-mono);
  font-size: 22px;
  color: var(--star);
  background: var(--nebula);
  border: 1px solid var(--nebula);
  box-shadow: 4px 4px 0 var(--shadow-deep);
}

.page-about .domain__name {
  margin: 0 0 6px;
  font-size: 16.5px;
  font-weight: 400;
  letter-spacing: 0.04em;
  color: var(--star);
}

.page-about .domain__desc {
  margin: 0 0 8px;
  font-size: 14.5px;
  line-height: 1.8;
  color: var(--dust);
}

.page-about .domain__fmt {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--pulse);
  background: rgba(57, 230, 208, 0.08);
  border: 1px solid rgba(57, 230, 208, 0.24);
  padding: 2px 7px;
  display: inline-block;
}

/* ---------- 更新时间三处 ---------- */
.page-about .spots {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 12px;
}

.page-about .spot {
  position: relative;
  border: 1px solid var(--line-orbit);
  border-left: 3px solid var(--nebula);
  background: var(--ink-night);
  padding: 18px 18px 18px 20px;
  transition: box-shadow var(--fast) var(--ease), transform var(--fast) var(--ease);
}

.page-about .spot:hover {
  transform: translateY(-2px);
  box-shadow: 6px 6px 0 var(--shadow-deep);
}

.page-about .spot__no {
  display: block;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.22em;
  color: var(--pulse);
  margin-bottom: 8px;
}

.page-about .spot__name {
  margin: 0 0 8px;
  font-size: 16.5px;
  font-weight: 400;
  letter-spacing: 0.04em;
  color: var(--star);
}

.page-about .spot__desc {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.85;
  color: var(--dust);
}

/* ---------- 维护节奏 ---------- */
.page-about .upkeep {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 24px;
}

.page-about .upkeep__title {
  margin: 0 0 16px;
  font-size: 15px;
  font-weight: 400;
  letter-spacing: 0.12em;
  color: var(--star);
  padding-bottom: 10px;
  border-bottom: 1px solid var(--line-orbit);
}

.page-about .upkeep__list {
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .upkeep__list li {
  display: grid;
  grid-template-columns: 62px minmax(0, 1fr);
  gap: 12px;
  align-items: baseline;
  padding: 12px 0;
  border-bottom: 1px dashed var(--line-orbit);
  font-size: 14.5px;
  line-height: 1.8;
  color: var(--dust);
}

.page-about .upkeep__list li:last-child {
  border-bottom: none;
}

.page-about .upkeep__k {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--pulse);
  background: rgba(57, 230, 208, 0.08);
  border: 1px solid rgba(57, 230, 208, 0.24);
  padding: 3px 0;
  text-align: center;
}

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

/* ---------- 终端视图 ---------- */
.page-about .term-grid {
  margin-top: clamp(24px, 4vw, 36px);
}

.page-about .term {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.page-about .term__version {
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.2em;
  color: var(--pulse);
}

.page-about .term__name {
  margin: 0;
  font-size: 16.5px;
  font-weight: 400;
  letter-spacing: 0.04em;
  color: var(--star);
}

.page-about .term__desc {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.85;
  color: var(--dust);
}

/* ---------- 团队分工 ---------- */
.page-about .team {
  margin: clamp(20px, 3vw, 30px) 0 0;
  border-top: 1px solid var(--line-orbit);
}

.page-about .team__row {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 6px;
  padding: 16px 0;
  border-bottom: 1px solid var(--line-orbit);
  transition: background var(--fast) var(--ease), padding-left var(--fast) var(--ease);
}

.page-about .team__row:hover {
  background: var(--ink-night);
  padding-left: 12px;
}

.page-about .team__name {
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.12em;
  color: var(--star);
}

.page-about .team__duty {
  font-size: 14.5px;
  line-height: 1.85;
  color: var(--dust);
}

/* ---------- 尾部指路 ---------- */
.page-about .about-next {
  border-top: 1px solid var(--line-orbit);
  background: var(--ink-night);
  padding-block: clamp(36px, 6vw, 64px);
}

.page-about .about-next__title {
  margin: 0 0 24px;
  font-size: clamp(1.25rem, 2.6vw, 1.7rem);
  font-weight: 250;
  letter-spacing: 0.06em;
  color: var(--star);
}

.page-about .about-next__links {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 10px;
}

.page-about .about-next__link {
  display: grid;
  grid-template-columns: 42px minmax(0, 1fr);
  gap: 14px;
  align-items: center;
  padding: 15px 16px;
  border: 1px solid var(--line-orbit);
  background: var(--ink-deep);
  color: var(--star);
  text-decoration: none;
  transition: border-color var(--fast) var(--ease), transform var(--fast) var(--ease), box-shadow var(--fast) var(--ease);
}

.page-about .about-next__link:hover,
.page-about .about-next__link:focus-visible {
  border-color: var(--pulse);
  transform: translate(-3px, -3px);
  box-shadow: 6px 6px 0 var(--shadow-deep);
  outline: none;
}

.page-about .about-next__idx {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 42px;
  height: 42px;
  font-family: var(--font-mono);
  font-size: 16px;
  color: var(--ink-deep);
  background: var(--pulse);
}

.page-about .about-next__label {
  font-size: 15px;
  line-height: 1.6;
  letter-spacing: 0.03em;
}

/* ---------- 中等屏幕 ---------- */
@media (min-width: 640px) {
  .page-about .domain-list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

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

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

@media (min-width: 900px) {
  .page-about .about-chapter__grid {
    grid-template-columns: var(--about-rail) minmax(0, 1fr);
    gap: 52px;
  }

  .page-about .about-rail {
    display: block;
    position: sticky;
    top: 96px;
    align-self: start;
  }

  .page-about .about-rail__idx {
    display: block;
    font-size: 42px;
    margin-bottom: 10px;
  }

  .page-about .about-rail__label {
    display: block;
    writing-mode: vertical-rl;
    letter-spacing: 0.34em;
    font-size: 11px;
  }

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

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

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

  .page-about .upkeep {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, 0.95fr);
    align-items: start;
    gap: 40px;
  }

  .page-about .team__row {
    grid-template-columns: 190px minmax(0, 1fr);
    align-items: baseline;
    gap: 24px;
  }

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

  .page-about .tl__more {
    max-height: 0;
    opacity: 0;
    margin-top: 0;
  }

  .page-about .tl__card:hover .tl__more,
  .page-about .tl__card:focus .tl__more,
  .page-about .tl__card:focus-within .tl__more {
    max-height: 260px;
    opacity: 1;
    margin-top: 10px;
  }
}

@media (min-width: 1200px) {
  .page-about .about-mast__title {
    max-width: 18ch;
  }

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

@media (prefers-reduced-motion: reduce) {
  .page-about .tl__dot,
  .page-about .tl__card,
  .page-about .tl__more,
  .page-about .domain,
  .page-about .spot,
  .page-about .team__row,
  .page-about .about-next__link {
    transition: none;
  }
}