.page-about {
  --rail-w: 268px;
  background-color: var(--paper);
  background-image: repeating-linear-gradient(135deg, rgba(200, 150, 46, 0.05) 0 1px, transparent 1px 10px);
  color: var(--ink);
  font-family: var(--font-body);
}

.page-about a {
  color: inherit;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  border-bottom: 1px solid var(--line);
}

.page-about .about-hero__inner {
  display: grid;
  gap: 24px;
  padding-block: 24px 36px;
}

.page-about .about-hero__copy {
  position: relative;
  padding-top: 14px;
}

.page-about .about-hero__copy::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 56px;
  height: 3px;
  background: linear-gradient(90deg, var(--cinnabar), var(--gold));
}

.page-about .about-hero h1 {
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: clamp(1.9rem, 6.4vw, 3.25rem);
  line-height: 1.18;
  letter-spacing: 0.01em;
  margin: 12px 0 16px;
  color: var(--ink);
}

.page-about .about-hero .lead {
  max-width: 40em;
  color: var(--brown);
  font-size: var(--fs-16);
  line-height: 1.85;
}

.page-about .about-hero__stamp {
  display: inline-block;
  margin-top: 18px;
  padding: 6px 12px;
  font-size: var(--fs-12);
  letter-spacing: 0.08em;
  color: var(--brown);
  background: rgba(232, 199, 122, 0.32);
  border: 1px dashed var(--gold);
  border-radius: 999px;
}

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

.page-about .about-hero__media .media__frame {
  aspect-ratio: 14 / 9;
  overflow: hidden;
  border: 1px solid var(--gold-line);
  border-radius: var(--radius);
  background: var(--brown);
  box-shadow: var(--shadow-card);
}

.page-about .about-hero__media .media__frame img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.page-about .media__caption {
  margin-top: 8px;
  font-size: var(--fs-12);
  color: var(--taupe);
  line-height: 1.6;
}

/* ---------- 分屏骨架 ---------- */
.page-about .about-body {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 28px;
  padding-block: 32px 64px;
}

.page-about .about-main {
  min-width: 0;
}

/* ---------- 左栏索引 ---------- */
.page-about .about-rail {
  background: rgba(255, 253, 247, 0.62);
  -webkit-backdrop-filter: blur(8px);
  backdrop-filter: blur(8px);
  border: 1px solid var(--gold-line);
  border-radius: var(--radius);
  padding: 16px 16px 18px;
  box-shadow: var(--shadow-card);
}

.page-about .rail__title {
  margin: 0;
  font-size: var(--fs-12);
  letter-spacing: 0.16em;
  color: var(--cinnabar);
}

.page-about .rail__list {
  position: relative;
  list-style: none;
  margin: 14px 0 0;
  padding: 0;
}

.page-about .rail__list::before {
  content: "";
  position: absolute;
  left: 6px;
  top: 10px;
  bottom: 10px;
  width: 1px;
  background: linear-gradient(var(--gold-line), rgba(200, 150, 46, 0.14));
}

.page-about .rail__item {
  position: relative;
  padding-left: 24px;
}

.page-about .rail__item::before {
  content: "";
  position: absolute;
  left: 1px;
  top: 50%;
  width: 11px;
  height: 11px;
  margin-top: -5.5px;
  border-radius: 50%;
  border: 1.5px solid var(--gold);
  background: var(--jade);
}

.page-about .rail__item::after {
  content: "";
  position: absolute;
  left: 5px;
  top: 50%;
  width: 3px;
  height: 3px;
  margin-top: -1.5px;
  border-radius: 50%;
  background: var(--gold);
}

.page-about .rail__link {
  display: flex;
  align-items: baseline;
  gap: 10px;
  padding: 10px 0;
  font-size: var(--fs-14);
  line-height: 1.45;
  color: var(--brown);
  text-decoration: none;
  border-bottom: 1px dashed rgba(74, 50, 36, 0.14);
  transition: color 0.22s var(--ease-out);
}

.page-about .rail__item:last-child .rail__link {
  border-bottom: 0;
}

.page-about .rail__link:hover,
.page-about .rail__link:focus-visible {
  color: var(--cinnabar);
}

.page-about .rail__link:focus-visible {
  outline: 2px solid var(--gold);
  outline-offset: 3px;
  border-radius: 3px;
}

.page-about .rail__num {
  flex: none;
  font-family: var(--font-mono);
  font-size: var(--fs-12);
  color: var(--gold);
  letter-spacing: 0.06em;
}

.page-about .rail__foot {
  margin-top: 16px;
  padding-top: 14px;
  border-top: 1px solid var(--line);
}

.page-about .rail__stat {
  margin: 0 0 6px;
  font-size: var(--fs-12);
  color: var(--taupe);
  line-height: 1.6;
}

.page-about .rail__stat-num {
  font-family: var(--font-mono);
  font-size: var(--fs-16);
  color: var(--ink);
  margin-right: 4px;
}

.page-about .rail__stamp {
  margin: 12px 0 0;
  font-size: var(--fs-12);
  letter-spacing: 0.06em;
  color: var(--patina);
}

/* ---------- 章节 ---------- */
.page-about .about-sec + .about-sec {
  margin-top: 52px;
}

.page-about .about-sec h2 {
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: clamp(1.45rem, 4.4vw, 2.25rem);
  line-height: 1.25;
  margin: 6px 0 0;
  color: var(--ink);
}

.page-about .about-sec__lead {
  max-width: 42em;
  margin: 16px 0 0;
  color: var(--brown);
  font-size: var(--fs-16);
  line-height: 1.85;
}

.page-about .about-sec .prose {
  margin-top: 16px;
  max-width: 72ch;
}

.page-about .about-sec .prose p {
  margin: 0 0 16px;
  font-size: var(--fs-16);
  line-height: 1.85;
  color: var(--ink);
}

.page-about .about-sec .prose > p:first-child {
  padding-left: 14px;
  border-left: 2px solid var(--gold-soft);
}

.page-about .about-sec .prose a {
  color: var(--cinnabar);
  text-decoration: underline;
  text-decoration-color: var(--gold-line);
  text-underline-offset: 3px;
}

.page-about .about-sec__tail {
  margin: 26px 0 0;
  max-width: 44em;
  font-size: var(--fs-14);
  line-height: 1.8;
  color: var(--taupe);
}

/* ---------- 旁注 ---------- */
.page-about .about-note {
  margin-top: 22px;
  padding: 14px 16px 16px 18px;
  background: rgba(232, 199, 122, 0.18);
  border-left: 3px solid var(--gold);
  border-radius: 0 var(--radius) var(--radius) 0;
  max-width: 46em;
}

.page-about .about-note__no {
  margin: 0 0 6px;
  font-family: var(--font-mono);
  font-size: var(--fs-12);
  letter-spacing: 0.12em;
  color: var(--taupe);
}

.page-about .about-note p:last-child {
  margin: 0;
  font-size: var(--fs-14);
  line-height: 1.8;
  color: var(--brown);
}

/* ---------- 年表 ---------- */
.page-about .about-timeline {
  display: grid;
  gap: 24px;
  margin-top: 24px;
}

.page-about .about-timeline__fig {
  margin: 0;
  max-width: 280px;
}

.page-about .about-timeline__fig .media__frame {
  aspect-ratio: 3 / 4;
  overflow: hidden;
  border: 1px solid var(--gold-line);
  border-radius: var(--radius);
  background: var(--brown);
}

.page-about .about-timeline__fig .media__frame img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.page-about .about-timeline__list {
  position: relative;
  min-width: 0;
}

.page-about .about-timeline__list::before {
  content: "";
  position: absolute;
  left: 5px;
  top: 26px;
  bottom: 22px;
  width: 1px;
  background: linear-gradient(var(--gold-line), rgba(200, 150, 46, 0.12));
}

.page-about .evt {
  border-top: 1px solid var(--line);
}

.page-about .evt:last-child {
  border-bottom: 1px solid var(--line);
}

.page-about .evt__sum {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  padding: 15px 0;
  list-style: none;
  cursor: pointer;
}

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

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

.page-about .evt__dot {
  flex: none;
  width: 11px;
  height: 11px;
  margin-top: 5px;
  border-radius: 50%;
  border: 2px solid var(--gold);
  background: var(--jade);
  box-shadow: 0 0 0 3px rgba(200, 150, 46, 0.16);
}

.page-about .evt__head {
  display: flex;
  flex-direction: column;
  gap: 4px;
  min-width: 0;
}

.page-about .evt__phase {
  font-family: var(--font-mono);
  font-size: var(--fs-12);
  letter-spacing: 0.1em;
  color: var(--cinnabar);
}

.page-about .evt__title {
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: var(--fs-18);
  line-height: 1.45;
  color: var(--ink);
}

.page-about .evt__hint {
  flex: none;
  margin-left: auto;
  align-self: center;
  font-family: var(--font-mono);
  font-size: var(--fs-14);
  color: var(--gold);
  line-height: 1;
}

.page-about .evt__hint::before {
  content: "＋";
}

.page-about .evt[open] .evt__hint::before {
  content: "－";
}

.page-about .evt__body {
  padding: 0 0 18px 23px;
}

.page-about .evt__body p {
  margin: 0;
  font-size: var(--fs-14);
  line-height: 1.85;
  color: var(--brown);
}

/* ---------- 团队 ---------- */
.page-about .about-team {
  display: grid;
  gap: 22px;
  margin-top: 24px;
}

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

.page-about .about-team__fig .media__frame {
  aspect-ratio: 4 / 3;
  overflow: hidden;
  border: 1px solid var(--gold-line);
  border-radius: var(--radius);
  background: var(--brown);
}

.page-about .about-team__fig .media__frame img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.page-about .about-team__list {
  margin: 0;
  display: grid;
  gap: 14px;
}

.page-about .team-item {
  padding: 14px 16px;
  background: var(--jade);
  border-top: 3px solid var(--gold);
  border-radius: 0 0 var(--radius) var(--radius);
  box-shadow: var(--shadow-card);
}

.page-about .team-item dt {
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: var(--fs-18);
  color: var(--ink);
  margin-bottom: 6px;
}

.page-about .team-item dd {
  margin: 0;
  font-size: var(--fs-14);
  line-height: 1.8;
  color: var(--brown);
}

/* ---------- 段位阶梯 ---------- */
.page-about .about-sec--wide .ranks {
  margin-top: 34px;
  margin-bottom: 8px;
}

.page-about .ranks {
  list-style: none;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 16px 14px;
}

.page-about .rank {
  display: grid;
  grid-template-rows: 1fr auto;
  gap: 10px;
  min-width: 0;
}

.page-about .rank__text {
  align-self: end;
  min-width: 0;
}

.page-about .rank__name {
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: var(--fs-18);
  margin: 0 0 6px;
  color: var(--ink);
}

.page-about .rank__goal {
  margin: 0 0 8px;
  font-size: var(--fs-14);
  line-height: 1.75;
  color: var(--brown);
}

.page-about .rank__layout {
  margin: 0;
  font-family: var(--font-mono);
  font-size: var(--fs-12);
  letter-spacing: 0.04em;
  color: var(--patina);
}

.page-about .rank__bar {
  display: flex;
  align-items: flex-start;
  justify-content: center;
  padding-top: 6px;
  border-radius: 3px 3px 0 0;
  background: linear-gradient(180deg, var(--gold-soft), rgba(200, 150, 46, 0.5));
  transition: transform 0.32s var(--ease-out), background 0.32s var(--ease-out);
}

.page-about .rank__lvl {
  font-family: var(--font-mono);
  font-size: var(--fs-12);
  color: var(--brown);
  letter-spacing: 0.08em;
}

.page-about .rank:hover .rank__bar,
.page-about .rank:focus-within .rank__bar {
  transform: translateY(-5px);
  background: linear-gradient(180deg, var(--cinnabar), var(--darkred));
}

.page-about .rank:hover .rank__lvl,
.page-about .rank:focus-within .rank__lvl {
  color: var(--jade);
}

.page-about .rank:nth-child(1) .rank__bar { height: 34px; }
.page-about .rank:nth-child(2) .rank__bar { height: 58px; }
.page-about .rank:nth-child(3) .rank__bar { height: 82px; }
.page-about .rank:nth-child(4) .rank__bar { height: 106px; }
.page-about .rank:nth-child(5) .rank__bar { height: 130px; }

/* ---------- 三级流程 ---------- */
.page-about .checks {
  list-style: none;
  margin: 26px 0 0;
  padding: 0;
  display: grid;
  gap: 14px;
}

.page-about .check {
  padding: 16px 16px 18px;
  background: var(--jade);
  border: 1px solid var(--line);
  border-top: 3px solid var(--gold);
  border-radius: 0 0 var(--radius) var(--radius);
  box-shadow: var(--shadow-card);
}

.page-about .check__no {
  margin: 0 0 8px;
  font-family: var(--font-mono);
  font-size: var(--fs-12);
  letter-spacing: 0.12em;
  color: var(--cinnabar);
}

.page-about .check__name {
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: var(--fs-18);
  margin: 0 0 8px;
  color: var(--ink);
}

.page-about .check__desc {
  margin: 0;
  font-size: var(--fs-14);
  line-height: 1.8;
  color: var(--brown);
}

.page-about .about-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 28px;
}

/* ---------- 继续翻阅 ---------- */
.page-about .about-next {
  margin-top: 52px;
  padding-top: 24px;
  border-top: 2px solid var(--line-strong);
}

.page-about .about-next h2 {
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: var(--fs-24);
  margin: 0;
  color: var(--ink);
}

.page-about .next__list {
  list-style: none;
  margin: 14px 0 0;
  padding: 0;
}

.page-about .next__item {
  border-bottom: 1px dashed var(--line);
}

.page-about .next__item:first-child {
  border-top: 1px dashed var(--line);
}

.page-about .next__link {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 4px 14px;
  padding: 13px 2px;
  text-decoration: none;
  color: var(--ink);
  transition: color 0.22s var(--ease-out), padding-left 0.22s var(--ease-out);
}

.page-about .next__link:hover,
.page-about .next__link:focus-visible {
  color: var(--cinnabar);
  padding-left: 8px;
}

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

.page-about .next__label {
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: var(--fs-18);
}

.page-about .next__desc {
  font-size: var(--fs-14);
  line-height: 1.7;
  color: var(--taupe);
}

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

/* ---------- 媒体查询 ---------- */
@media (min-width: 720px) {
  .page-about .checks {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

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

  .page-about .ranks {
    grid-template-columns: repeat(5, minmax(0, 1fr));
    gap: 10px;
  }

  .page-about .about-hero__inner {
    gap: 32px;
    padding-block: 32px 48px;
  }
}

@media (min-width: 900px) {
  .page-about .about-body {
    grid-template-columns: var(--rail-w) minmax(0, 1fr);
    gap: 56px;
    padding-block: 44px 80px;
  }

  .page-about .about-rail {
    position: sticky;
    top: 28px;
    align-self: start;
  }

  .page-about .about-hero__inner {
    grid-template-columns: minmax(0, 1.02fr) minmax(0, 1fr);
    align-items: center;
    gap: 48px;
    padding-block: 40px 56px;
  }

  .page-about .about-timeline {
    grid-template-columns: 250px minmax(0, 1fr);
    gap: 40px;
    align-items: start;
  }

  .page-about .about-timeline__fig {
    position: sticky;
    top: 32px;
  }

  .page-about .about-team {
    grid-template-columns: minmax(0, 0.9fr) minmax(0, 1.35fr);
    gap: 32px;
    align-items: start;
  }

  .page-about .about-team__list {
    grid-template-columns: minmax(0, 1fr);
    gap: 12px;
  }

  .page-about .about-sec--wide .ranks {
    margin-top: 44px;
  }

  .page-about .rank:nth-child(1) .rank__bar { height: 44px; }
  .page-about .rank:nth-child(2) .rank__bar { height: 76px; }
  .page-about .rank:nth-child(3) .rank__bar { height: 108px; }
  .page-about .rank:nth-child(4) .rank__bar { height: 140px; }
  .page-about .rank:nth-child(5) .rank__bar { height: 172px; }
}

@media (min-width: 1160px) {
  .page-about .about-hero__inner {
    padding-block: 52px 64px;
  }

  .page-about .about-sec + .about-sec {
    margin-top: 64px;
  }
}

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

  .page-about .rank:hover .rank__bar,
  .page-about .rank:focus-within .rank__bar {
    transform: none;
  }
}