.page-about {
  --about-rail-w: 132px;
  --about-gap: 40px;
  padding-bottom: 84px;
}

/* ---------- 面包屑 ---------- */
.page-about .about-crumb {
  padding: 26px 0 4px;
  font-size: var(--fs-14);
  color: var(--c-stone);
}
.page-about .about-crumb a {
  color: rgba(244, 241, 232, .72);
  text-decoration: none;
  border-bottom: 1px solid transparent;
}
.page-about .about-crumb a:hover {
  color: var(--c-cyan);
  border-bottom-color: rgba(53, 227, 210, .45);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  padding: 40px 0 44px;
  overflow: hidden;
}
.page-about .about-hero::after {
  content: "";
  position: absolute;
  top: -30px;
  right: -70px;
  width: 190px;
  height: 190px;
  border: 1px solid rgba(201, 162, 39, .28);
  transform: rotate(45deg);
  pointer-events: none;
}
.page-about .about-hero__tag {
  margin: 0;
  font-size: var(--fs-12);
  letter-spacing: .12em;
  color: var(--c-gold);
  text-transform: uppercase;
}
.page-about .about-hero__title {
  margin: 14px 0 0;
  font-family: var(--font-display);
  font-weight: 600;
  letter-spacing: .02em;
  line-height: 1.24;
  font-size: var(--fs-28);
  color: var(--c-cream);
  max-width: 20em;
}
.page-about .about-hero__lede {
  margin: 20px 0 0;
  max-width: 44em;
  font-size: var(--fs-16);
  line-height: 1.78;
  color: rgba(244, 241, 232, .8);
}
.page-about .about-hero__facts {
  list-style: none;
  margin: 32px 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}
.page-about .about-hero__facts li {
  background: var(--c-pine-2);
  padding: 16px 16px 18px;
  font-size: var(--fs-12);
  line-height: 1.5;
  color: rgba(244, 241, 232, .68);
}
.page-about .about-hero__facts .mono {
  display: block;
  margin-bottom: 6px;
  font-size: var(--fs-20);
  color: var(--c-gold);
  letter-spacing: .02em;
}

/* ---------- 主体两栏 ---------- */
.page-about .about-body {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 26px;
  padding-top: 8px;
}

/* ---------- 年份轨道 ---------- */
.page-about .year-rail {
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  padding: 10px 0;
}
.page-about .year-rail__label {
  display: none;
}
.page-about .year-rail__list {
  list-style: none;
  margin: 0;
  padding: 0 2px 2px;
  display: flex;
  gap: 8px;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
}
.page-about .year-rail__list li {
  flex: 0 0 auto;
}
.page-about .year-rail__link {
  display: inline-flex;
  align-items: baseline;
  gap: 8px;
  padding: 7px 12px;
  border: 1px solid var(--line);
  text-decoration: none;
  white-space: nowrap;
  font-size: var(--fs-12);
  transition: border-color .18s ease, background-color .18s ease;
}
.page-about .year-rail__y {
  color: var(--c-gold);
  font-size: var(--fs-12);
}
.page-about .year-rail__t {
  color: rgba(244, 241, 232, .72);
}
.page-about .year-rail__link:hover,
.page-about .year-rail__link:focus-visible {
  border-color: var(--c-gold);
  background: rgba(201, 162, 39, .08);
}

/* ---------- 章节列表 ---------- */
.page-about .about-chapters {
  display: grid;
  gap: 54px;
  min-width: 0;
}
.page-about .chapter {
  position: relative;
  scroll-margin-top: 24px;
}
.page-about .chapter__head {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  grid-template-areas:
    "num title"
    ".   meta";
  column-gap: 14px;
  align-items: baseline;
  padding-bottom: 14px;
  margin-bottom: 22px;
  border-bottom: 1px solid var(--line);
}
.page-about .chapter__num {
  grid-area: num;
  font-size: var(--fs-14);
  letter-spacing: .1em;
  color: var(--c-gold);
}
.page-about .chapter__title {
  grid-area: title;
  margin: 0;
  font-family: var(--font-display);
  font-weight: 600;
  letter-spacing: .02em;
  line-height: 1.34;
  font-size: var(--fs-20);
  color: var(--c-cream);
}
.page-about .chapter__meta {
  grid-area: meta;
  margin: 6px 0 0;
  font-size: var(--fs-12);
  color: var(--c-stone);
}
.page-about .chapter:target .chapter__head {
  border-bottom-color: var(--c-gold);
}

.page-about .chapter__text p,
.page-about .chapter > p {
  margin: 0 0 1.1em;
  max-width: 44em;
  font-size: var(--fs-16);
  line-height: 1.78;
  color: rgba(244, 241, 232, .82);
}
.page-about .chapter__text p:last-child,
.page-about .chapter > p:last-child {
  margin-bottom: 0;
}
.page-about .chapter__lede {
  font-size: var(--fs-16);
  line-height: 1.78;
  color: rgba(244, 241, 232, .82);
  max-width: 44em;
  margin: 0 0 1.1em;
}
.page-about .chapter a.about-link,
.page-about .chapter__text p a {
  color: var(--c-cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(53, 227, 210, .4);
}
.page-about .chapter a.about-link:hover,
.page-about .chapter__text p a:hover {
  border-bottom-color: var(--c-cyan);
}

/* 实色米白章节 */
.page-about .chapter--solid {
  background: var(--c-cream);
  padding: 30px 22px 32px;
  color: var(--c-pine);
}
.page-about .chapter--solid .chapter__head {
  border-bottom-color: rgba(11, 33, 27, .16);
}
.page-about .chapter--solid .chapter__title { color: var(--c-pine); }
.page-about .chapter--solid .chapter__num { color: var(--c-clay); }
.page-about .chapter--solid .chapter__meta { color: var(--c-stone); }
.page-about .chapter--solid .chapter__text p,
.page-about .chapter--solid .chapter > p,
.page-about .chapter--solid .chapter__lede {
  color: rgba(11, 33, 27, .84);
}
.page-about .chapter--solid .chapter__text p a,
.page-about .chapter--solid .chapter a.about-link {
  color: var(--c-moss);
  border-bottom-color: rgba(63, 107, 84, .45);
}
.page-about .chapter--solid .media-frame {
  border-color: rgba(11, 33, 27, .16);
  background: rgba(11, 33, 27, .05);
}
.page-about .chapter--solid .media-frame__cap {
  border-top-color: rgba(11, 33, 27, .16);
  color: var(--c-stone);
}

/* 章节内两栏 */
.page-about .chapter__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 24px;
}
.page-about .chapter__media {
  margin: 0;
}

/* ---------- 图片框 ---------- */
.page-about .media-frame {
  position: relative;
  display: flex;
  flex-direction: column;
  overflow: hidden;
  border: 1px solid var(--line);
  background: var(--c-pine-2);
}
.page-about .media-frame img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  aspect-ratio: 3 / 2;
  object-fit: cover;
}
.page-about .media-frame--square img {
  aspect-ratio: 1 / 1;
}
.page-about .media-frame__cap {
  padding: 10px 13px;
  font-size: var(--fs-12);
  line-height: 1.6;
  color: var(--c-stone);
  border-top: 1px solid var(--line);
}

/* ---------- 房间分类图 ---------- */
.page-about .room-map {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 16px;
  margin: 26px 0 22px;
}
.page-about .room-map__col {
  padding: 18px 18px 20px;
  border: 1px solid rgba(11, 33, 27, .18);
  border-top: 2px solid var(--c-moss);
  background: rgba(11, 33, 27, .045);
}
.page-about .room-map__col--game {
  border-top-color: var(--c-clay);
}
.page-about .room-map__title {
  display: flex;
  align-items: baseline;
  gap: 10px;
  margin: 0 0 6px;
  font-family: var(--font-display);
  font-weight: 600;
  letter-spacing: .02em;
  font-size: var(--fs-20);
  color: var(--c-pine);
}
.page-about .room-map__title .mono {
  font-size: var(--fs-14);
  color: var(--c-clay);
}
.page-about .room-map__desc {
  margin: 0 0 14px;
  font-size: var(--fs-12);
  color: var(--c-stone);
}
.page-about .room-map__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 9px 16px;
}
.page-about .room-map__list li {
  position: relative;
  padding-left: 15px;
  font-size: var(--fs-14);
  line-height: 1.6;
  color: rgba(11, 33, 27, .8);
}
.page-about .room-map__list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: .72em;
  width: 7px;
  height: 1px;
  background: var(--c-clay);
}

/* ---------- 团队卡片 ---------- */
.page-about .team-cards {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 14px;
  margin-top: 22px;
}
.page-about .team-card {
  border: 1px solid var(--line);
  background: rgba(20, 51, 40, .55);
  backdrop-filter: blur(6px);
  -webkit-backdrop-filter: blur(6px);
}
.page-about .team-card__summary {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 16px 16px;
  cursor: pointer;
  list-style: none;
}
.page-about .team-card__summary::-webkit-details-marker { display: none; }
.page-about .team-card__summary::marker { content: ""; }
.page-about .team-card__num {
  font-size: var(--fs-12);
  color: var(--c-gold);
}
.page-about .team-card__name {
  font-family: var(--font-display);
  font-size: var(--fs-16);
  letter-spacing: .04em;
  color: var(--c-cream);
}
.page-about .team-card__hint {
  margin-left: auto;
  font-size: var(--fs-12);
  color: var(--c-cyan);
}
.page-about .team-card__hint--open { display: none; }
.page-about .team-card[open] .team-card__hint--open { display: inline; }
.page-about .team-card[open] .team-card__hint--closed { display: none; }
.page-about .team-card__body {
  border-top: 1px solid var(--line);
  padding: 14px 16px 18px;
}
.page-about .team-card__body p {
  margin: 0;
  font-size: var(--fs-14);
  line-height: 1.78;
  color: rgba(244, 241, 232, .78);
}

/* ---------- 长期做法 ---------- */
.page-about .principle-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}
.page-about .principle {
  background: var(--c-pine-2);
  padding: 22px 20px 24px;
}
.page-about .principle__num {
  display: block;
  margin-bottom: 10px;
  font-size: var(--fs-12);
  color: var(--c-gold);
}
.page-about .principle__title {
  margin: 0 0 10px;
  font-family: var(--font-display);
  font-weight: 600;
  letter-spacing: .02em;
  font-size: var(--fs-16);
  color: var(--c-cream);
}
.page-about .principle p {
  margin: 0;
  font-size: var(--fs-14);
  line-height: 1.78;
  color: rgba(244, 241, 232, .76);
}

/* ---------- 收束区 ---------- */
.page-about .about-cta {
  position: relative;
  margin-top: 64px;
  padding: 30px 22px 32px;
  border: 1px solid rgba(201, 162, 39, .3);
  background: linear-gradient(140deg, rgba(20, 51, 40, .92), rgba(10, 15, 18, .96));
  overflow: hidden;
}
.page-about .about-cta::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 72px;
  height: 2px;
  background: var(--c-gold);
}
.page-about .about-cta__title {
  margin: 0 0 12px;
  font-family: var(--font-display);
  font-weight: 600;
  letter-spacing: .02em;
  font-size: var(--fs-20);
  color: var(--c-cream);
}
.page-about .about-cta__text {
  margin: 0;
  max-width: 42em;
  font-size: var(--fs-14);
  line-height: 1.78;
  color: rgba(244, 241, 232, .78);
}
.page-about .about-cta__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 22px;
}

/* ---------- 平板及桌面 ---------- */
@media (min-width: 720px) {
  .page-about .about-hero { padding: 56px 0 52px; }
  .page-about .about-hero__title { font-size: var(--fs-40); }
  .page-about .about-hero__facts { grid-template-columns: repeat(4, minmax(0, 1fr)); }
  .page-about .about-hero__facts li { padding: 18px 18px 20px; }

  .page-about .chapter__title { font-size: var(--fs-28); }
  .page-about .chapter--solid { padding: 40px 36px 42px; }
  .page-about .about-chapters { gap: 70px; }

  .page-about .room-map { grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 22px; }
  .page-about .team-cards { gap: 16px; }
  .page-about .about-cta { padding: 40px 36px 42px; }
  .page-about .about-cta__title { font-size: var(--fs-28); }
}

@media (min-width: 900px) {
  .page-about .chapter__grid {
    grid-template-columns: minmax(0, 1.15fr) minmax(0, .85fr);
    gap: 34px;
    align-items: start;
  }
  .page-about .chapter__grid--flip {
    grid-template-columns: minmax(0, .85fr) minmax(0, 1.15fr);
  }
  .page-about .chapter__grid--flip .chapter__media { order: -1; }
  .page-about .team-cards { grid-template-columns: repeat(3, minmax(0, 1fr)); }
  .page-about .principle-list { grid-template-columns: repeat(3, minmax(0, 1fr)); }
}

@media (min-width: 1024px) {
  .page-about .about-body {
    grid-template-columns: var(--about-rail-w) minmax(0, 1fr);
    gap: var(--about-gap);
    align-items: start;
  }

  .page-about .year-rail {
    position: sticky;
    top: 30px;
    border-top: 0;
    border-bottom: 0;
    padding: 0;
  }
  .page-about .year-rail__label {
    display: block;
    margin: 0 0 16px;
    font-size: var(--fs-12);
    letter-spacing: .14em;
    color: var(--c-stone);
  }
  .page-about .year-rail__list {
    display: block;
    overflow: visible;
    padding: 0 0 0 18px;
    position: relative;
  }
  .page-about .year-rail__list::before {
    content: "";
    position: absolute;
    left: 4px;
    top: 12px;
    bottom: 12px;
    width: 1px;
    background: linear-gradient(180deg, var(--c-clay), rgba(89, 99, 94, .4) 72%, rgba(89, 99, 94, 0));
  }
  .page-about .year-rail__list li { flex: initial; }
  .page-about .year-rail__link {
    display: flex;
    flex-direction: column;
    gap: 3px;
    padding: 9px 0;
    border: 0;
    white-space: normal;
    position: relative;
    background: transparent;
  }
  .page-about .year-rail__link::before {
    content: "";
    position: absolute;
    left: -18px;
    top: 16px;
    width: 9px;
    height: 9px;
    border-radius: 50%;
    border: 1px solid var(--c-clay);
    background: var(--c-pine);
    transition: background-color .2s ease, border-color .2s ease, box-shadow .2s ease;
  }
  .page-about .year-rail__link:hover,
  .page-about .year-rail__link:focus-visible {
    background: transparent;
    border-color: transparent;
  }
  .page-about .year-rail__link:hover::before,
  .page-about .year-rail__link:focus-visible::before {
    background: var(--c-cyan);
    border-color: var(--c-cyan);
    box-shadow: 0 0 0 4px rgba(53, 227, 210, .14);
  }
  .page-about .year-rail__link:hover .year-rail__t,
  .page-about .year-rail__link:focus-visible .year-rail__t {
    color: var(--c-cream);
  }
  .page-about .year-rail__y { font-size: var(--fs-14); }
  .page-about .year-rail__t { font-size: var(--fs-12); line-height: 1.4; }

  .page-about .about-hero__title { font-size: var(--fs-56); }
  .page-about .media-frame--square { max-width: 420px; }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .year-rail__link,
  .page-about .year-rail__link::before {
    transition: none;
  }
}