.page-about {
  --about-flow: linear-gradient(90deg, var(--indigo) 0%, var(--cinnabar) 100%);
}

.page-about .breadcrumb {
  padding-top: 20px;
}

/* ---------- 卷首 ---------- */
.page-about .about-hero {
  padding-block: clamp(26px, 4.5vw, 56px) clamp(44px, 7vw, 92px);
}

.page-about .about-hero__grid {
  display: grid;
  gap: 24px;
  margin-top: 18px;
}

.page-about .about-hero__index {
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding-left: 16px;
  border-left: 3px solid var(--cinnabar);
}

.page-about .about-hero__year {
  font-family: var(--font-mono);
  font-weight: 500;
  font-size: clamp(40px, 8vw, 66px);
  line-height: 1;
  letter-spacing: 0.01em;
  color: var(--ink);
}

.page-about .about-hero__ver {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--cinnabar);
}

.page-about .about-hero__lead h1 {
  margin: 0;
  font-family: var(--font-title);
  font-weight: 700;
  font-size: clamp(30px, 4.8vw, 52px);
  line-height: 1.28;
  color: var(--ink);
  text-wrap: balance;
}

.page-about .about-hero__intro {
  margin: 20px 0 0;
  max-width: 56ch;
  font-size: clamp(16px, 1.5vw, 18px);
  line-height: 1.9;
  color: var(--ink-deep);
}

.page-about .about-facts {
  margin: 32px 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--edge);
  border: 1px solid var(--edge);
}

.page-about .about-facts > div {
  background: var(--paper-card);
  padding: 14px 16px;
  min-width: 0;
}

.page-about .about-facts dt {
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--stone);
}

.page-about .about-facts dd {
  margin: 6px 0 0;
  font-family: var(--font-mono);
  font-size: 19px;
  color: var(--ink);
}

@media (min-width: 720px) {
  .page-about .about-facts {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

@media (min-width: 900px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 0.26fr) minmax(0, 1fr);
    gap: clamp(32px, 5vw, 72px);
    align-items: start;
  }
}

/* ---------- 通用章节 ---------- */
.page-about .about-section {
  padding-block: clamp(44px, 6vw, 84px);
}

.page-about .about-section + .about-section {
  border-top: 1px solid var(--edge);
}

.page-about .about-section h2 {
  margin: 10px 0 0;
  font-family: var(--font-title);
  font-weight: 700;
  font-size: clamp(24px, 3.4vw, 36px);
  line-height: 1.34;
  color: var(--ink);
  text-wrap: balance;
}

.page-about .about-lead {
  margin: 16px 0 0;
  max-width: 62ch;
  font-size: 16px;
  line-height: 1.9;
  color: var(--ink-deep);
}

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

.page-about .about-figure .figure__frame {
  background: var(--paper-card);
  border: 1px solid var(--edge);
  padding: 8px;
  box-shadow: var(--shadow-paper);
}

.page-about .about-figure .figure__img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
}

.page-about .about-figure .figure__caption {
  margin-top: 12px;
  font-size: 13px;
  line-height: 1.7;
  color: var(--stone);
}

/* ---------- 品牌声明 ---------- */
.page-about .about-statement__grid {
  display: grid;
  gap: 32px;
}

.page-about .about-statement__prose {
  margin-top: 20px;
}

.page-about .about-statement__prose p {
  margin: 0 0 18px;
}

.page-about .about-note {
  margin: 26px 0 0;
  padding: 16px 18px;
  max-width: 46ch;
  background: var(--paper-card);
  border-left: 3px solid var(--gold);
  font-size: 14px;
  line-height: 1.8;
  color: var(--stone);
  transition: transform 0.2s ease, box-shadow 0.2s ease, color 0.2s ease;
}

.page-about .about-note:hover,
.page-about .about-note:focus-within {
  transform: translate(-2px, -2px);
  box-shadow: var(--shadow-paper);
  color: var(--ink-deep);
}

@media (min-width: 900px) {
  .page-about .about-statement__grid {
    grid-template-columns: minmax(0, 1fr) minmax(0, 0.58fr);
    gap: clamp(32px, 5vw, 72px);
    align-items: start;
  }
}

/* ---------- 演进时间轴 ---------- */
.page-about .about-timeline__figure {
  margin: clamp(24px, 4vw, 40px) 0 clamp(28px, 4vw, 48px);
}

.page-about .about-timeline__body {
  display: grid;
  gap: 28px;
}

.page-about .era-index {
  min-width: 0;
}

.page-about .era-index ol {
  list-style: none;
  margin: 0;
  padding: 0 0 8px;
  display: flex;
  gap: 8px;
  overflow-x: auto;
}

.page-about .era-index li {
  flex: 0 0 auto;
}

.page-about .era-index a {
  display: flex;
  flex-direction: column;
  gap: 3px;
  min-width: 104px;
  padding: 9px 12px;
  border: 1px solid var(--edge);
  background: var(--paper-card);
  text-decoration: none;
  color: var(--ink);
  transition: border-color 0.18s ease, box-shadow 0.18s ease;
}

.page-about .era-index a:hover {
  border-color: var(--cinnabar-soft);
}

.page-about .era-index a:focus-visible {
  outline: 2px solid var(--cinnabar);
  outline-offset: 2px;
}

.page-about .era-index a[aria-current="true"] {
  border-color: var(--cinnabar);
  box-shadow: inset 3px 0 0 var(--cinnabar);
}

.page-about .era-index__ver {
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.08em;
  color: var(--cinnabar);
}

.page-about .era-index__name {
  font-size: 12px;
  line-height: 1.5;
  color: var(--stone);
}

.page-about .era-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 28px 24px;
}

.page-about .era {
  --era-accent: var(--indigo);
  position: relative;
  min-width: 0;
  padding-top: 26px;
}

.page-about .era:nth-child(3),
.page-about .era:nth-child(4) {
  --era-accent: var(--cinnabar);
}

.page-about .era::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: var(--era-accent);
}

.page-about .era::after {
  content: "";
  position: absolute;
  top: -5px;
  left: 0;
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--paper);
  border: 3px solid var(--era-accent);
  box-sizing: border-box;
}

.page-about .era__ver {
  display: block;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--era-accent);
}

.page-about .era__title {
  margin: 8px 0 0;
  font-family: var(--font-title);
  font-size: 19px;
  line-height: 1.45;
  color: var(--ink);
}

.page-about .era__body {
  margin: 10px 0 0;
  font-size: 15px;
  line-height: 1.85;
  color: var(--ink-deep);
}

.page-about .era__more {
  margin-top: 12px;
  border-top: 1px dashed var(--edge);
  padding-top: 8px;
}

.page-about .era__more summary {
  cursor: pointer;
  list-style: none;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--era-accent);
  padding: 4px 0;
}

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

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

.page-about .era__more[open] summary::before {
  content: "－ ";
}

.page-about .era__more summary:focus-visible {
  outline: 2px solid var(--cinnabar);
  outline-offset: 2px;
}

.page-about .era__more p {
  margin: 8px 0 0;
  font-size: 14px;
  line-height: 1.85;
  color: var(--stone);
}

@media (min-width: 760px) {
  .page-about .era-list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (min-width: 1024px) {
  .page-about .about-timeline__body {
    grid-template-columns: 176px minmax(0, 1fr);
    gap: clamp(28px, 4vw, 56px);
    align-items: start;
  }

  .page-about .era-index {
    position: sticky;
    top: calc(var(--topbar-h) + 28px);
  }

  .page-about .era-index ol {
    flex-direction: column;
    overflow: visible;
    padding-bottom: 0;
  }

  .page-about .era-index a {
    min-width: 0;
  }
}

@media (min-width: 1360px) {
  .page-about .era-list {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 20px;
  }

  .page-about .era__title {
    font-size: 18px;
  }
}

/* ---------- 内容整理 ---------- */
.page-about .about-method__grid {
  display: grid;
  gap: 32px;
}

.page-about .about-method__prose {
  margin-top: 20px;
}

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

.page-about .method-list {
  list-style: none;
  margin: 26px 0 0;
  padding: 0;
  display: grid;
  gap: 18px;
}

.page-about .method-list li {
  display: grid;
  grid-template-columns: 40px minmax(0, 1fr);
  gap: 14px;
  padding-top: 16px;
  border-top: 1px solid var(--edge);
}

.page-about .method-list__idx {
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.08em;
  color: var(--gold);
  padding-top: 3px;
}

.page-about .method-list h3 {
  margin: 0;
  font-family: var(--font-sans);
  font-weight: 700;
  font-size: 17px;
  line-height: 1.5;
  color: var(--ink);
}

.page-about .method-list p {
  margin: 6px 0 0;
  font-size: 15px;
  line-height: 1.85;
  color: var(--ink-deep);
}

@media (min-width: 900px) {
  .page-about .about-method__grid {
    grid-template-columns: minmax(0, 0.7fr) minmax(0, 1fr);
    gap: clamp(32px, 5vw, 72px);
    align-items: start;
  }

  .page-about .about-method__figure {
    position: sticky;
    top: calc(var(--topbar-h) + 28px);
  }
}

/* ---------- 团队与协作 ---------- */
.page-about .about-team__grid {
  display: grid;
  gap: 28px;
  margin-top: 32px;
}

.page-about .role {
  display: grid;
  grid-template-columns: 56px minmax(0, 1fr);
  gap: 16px;
  padding: 20px 0;
  border-top: 1px solid var(--edge);
}

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

.page-about .role__num {
  font-family: var(--font-mono);
  font-size: 30px;
  line-height: 1;
  color: var(--cinnabar);
}

.page-about .role h3 {
  margin: 0;
  font-family: var(--font-sans);
  font-weight: 700;
  font-size: 17px;
  color: var(--ink);
}

.page-about .role p {
  margin: 6px 0 0;
  font-size: 15px;
  line-height: 1.85;
  color: var(--ink-deep);
}

.page-about .about-team__aside {
  background: var(--ink);
  color: var(--paper);
  padding: clamp(24px, 3vw, 34px);
  box-shadow: var(--shadow-paper);
}

.page-about .about-team__aside h3 {
  margin: 0 0 14px;
  font-family: var(--font-title);
  font-size: 20px;
  line-height: 1.5;
  color: var(--paper);
}

.page-about .about-team__aside p {
  margin: 0 0 16px;
  font-size: 14.5px;
  line-height: 1.9;
  color: rgba(246, 240, 228, 0.86);
}

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

.page-about .aside-figures {
  display: flex;
  flex-wrap: wrap;
  gap: 22px 32px;
  margin: 0 0 18px;
  padding: 16px 0;
  border-top: 1px solid rgba(198, 161, 91, 0.42);
  border-bottom: 1px solid rgba(198, 161, 91, 0.42);
}

.page-about .aside-figures > div {
  display: flex;
  flex-direction: column;
  gap: 4px;
  min-width: 0;
}

.page-about .aside-figures__num {
  font-family: var(--font-mono);
  font-size: 26px;
  line-height: 1;
  color: var(--gold);
}

.page-about .aside-figures__label {
  font-size: 12px;
  letter-spacing: 0.06em;
  color: rgba(246, 240, 228, 0.75);
}

@media (min-width: 900px) {
  .page-about .about-team__grid {
    grid-template-columns: minmax(0, 1fr) minmax(0, 0.62fr);
    gap: clamp(28px, 4vw, 56px);
    align-items: start;
  }
}

/* ---------- 接下来的入口 ---------- */
.page-about .about-next__panel {
  background: var(--paper-card);
  border: 1px solid var(--edge);
  border-left: 4px solid var(--cinnabar);
  padding: clamp(24px, 4vw, 48px);
}

.page-about .about-next__links {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 26px;
}

/* ---------- 动效偏好 ---------- */
@media (prefers-reduced-motion: reduce) {
  .page-about .about-note,
  .page-about .era-index a {
    transition: none;
  }

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