.page-about {
  display: block;
  background: var(--c-main);
  color: var(--c-text);
  font-family: var(--font-body);
}

/* ---------- 面包屑 ---------- */
.page-about .about-crumb {
  padding-top: clamp(20px, 4vw, 38px);
}

.page-about .breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px;
  margin: 0;
  padding: 0;
  list-style: none;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--c-muted);
}

.page-about .breadcrumb a {
  color: var(--c-muted);
  text-decoration: none;
  transition: color var(--dur) var(--ease);
}

.page-about .breadcrumb a:hover,
.page-about .breadcrumb a:focus-visible {
  color: var(--c-amber);
}

.page-about .breadcrumb a[aria-current="page"] {
  color: var(--c-text);
}

.page-about .breadcrumb-sep {
  color: var(--c-dim);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  padding: clamp(36px, 7vw, 96px) 0 clamp(36px, 6vw, 72px);
  background:
    radial-gradient(120% 90% at 10% 0%, rgba(242, 179, 61, 0.10), transparent 58%),
    linear-gradient(180deg, var(--c-dome) 0%, var(--c-main) 84%);
}

.page-about .about-hero-title {
  margin: 18px 0 0;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(38px, 7.4vw, 74px);
  line-height: 1.02;
  letter-spacing: -0.02em;
  color: var(--c-text);
  max-width: 16ch;
}

.page-about .about-br {
  display: none;
}

.page-about .about-hero-lede {
  max-width: 34em;
  margin: 22px 0 0;
  font-size: 17px;
  line-height: 1.8;
  color: var(--c-muted);
}

.page-about .about-facts {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: 42px 0 0;
  padding: 0;
  background: var(--c-line);
  border: 1px solid var(--c-line);
  border-radius: var(--radius);
  overflow: hidden;
}

.page-about .about-fact {
  margin: 0;
  padding: 18px 16px;
  background: var(--c-panel);
  transition: background var(--dur) var(--ease);
}

.page-about .about-fact:hover {
  background: var(--c-panel-hi);
}

.page-about .about-fact dt {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  color: var(--c-muted);
}

.page-about .about-fact dd {
  margin: 8px 0 0;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 26px;
  line-height: 1.1;
  color: var(--c-text);
}

/* ---------- 章节索引 ---------- */
.page-about .about-index {
  padding: clamp(38px, 5vw, 68px) 0;
  border-top: 1px solid var(--c-line);
  background: var(--c-main);
}

.page-about .about-index-title {
  margin: 0 0 20px;
  font-family: var(--font-mono);
  font-weight: 500;
  font-size: 12px;
  letter-spacing: 0.18em;
  color: var(--c-muted);
}

.page-about .about-index-list {
  list-style: none;
  margin: 0;
  padding: 0;
  border-top: 1px solid var(--c-line);
}

.page-about .about-index-list a {
  display: flex;
  align-items: baseline;
  gap: 16px;
  padding: 14px 0;
  border-bottom: 1px solid var(--c-line);
  font-size: 15px;
  line-height: 1.5;
  color: var(--c-text);
  text-decoration: none;
  transition: color var(--dur) var(--ease), padding-left var(--dur) var(--ease);
}

.page-about .about-index-num {
  flex: none;
  width: 2.4em;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--c-amber);
}

.page-about .about-index-list a:hover,
.page-about .about-index-list a:focus-visible {
  color: var(--c-amber);
  padding-left: 8px;
}

/* ---------- 正文章节 ---------- */
.page-about .about-chapter {
  padding: clamp(42px, 6vw, 86px) 0;
  border-top: 1px solid var(--c-line);
  scroll-margin-top: 96px;
}

.page-about .about-chapter-num {
  margin: 0 0 12px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.2em;
  color: var(--c-amber);
}

.page-about .about-chapter h2 {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(26px, 4.6vw, 42px);
  line-height: 1.12;
  letter-spacing: -0.015em;
  color: var(--c-text);
  max-width: 18ch;
}

.page-about .about-chapter-kicker {
  margin: 10px 0 0;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--c-muted);
}

.page-about .about-body {
  margin-top: 26px;
}

.page-about .about-body > p {
  max-width: 34em;
  margin: 0 0 1.05em;
  font-size: 16px;
  line-height: 1.8;
  color: var(--c-text);
}

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

/* ---------- 分工示意 ---------- */
.page-about .about-diagram-scroll {
  margin: 30px 0 0;
  overflow-x: auto;
  overscroll-behavior-x: contain;
}

.page-about .about-diagram {
  display: block;
  width: 100%;
  min-width: 560px;
  height: auto;
}

/* ---------- 职能卡片 ---------- */
.page-about .about-roles {
  list-style: none;
  display: grid;
  gap: 1px;
  margin: 30px 0 0;
  padding: 0;
  background: var(--c-line);
  border: 1px solid var(--c-line);
  border-radius: var(--radius);
  overflow: hidden;
}

.page-about .about-role {
  padding: 22px 20px 24px;
  background: var(--c-panel);
  transition: background var(--dur) var(--ease);
}

.page-about .about-role:hover {
  background: var(--c-panel-hi);
}

.page-about .about-role h3 {
  margin: 0 0 10px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 20px;
  line-height: 1.3;
  color: var(--c-text);
}

.page-about .about-role p {
  margin: 0;
  font-size: 14px;
  line-height: 1.75;
  color: var(--c-muted);
}

/* ---------- 更新日志式列表 ---------- */
.page-about .about-log {
  list-style: none;
  margin: 30px 0 0;
  padding: 0;
  border-top: 1px solid var(--c-line);
}

.page-about .about-log-item {
  display: grid;
  grid-template-columns: 1fr;
  gap: 6px;
  padding: 16px 0;
  border-bottom: 1px solid var(--c-line);
  transition: border-color var(--dur) var(--ease);
}

.page-about .about-log-item:hover,
.page-about .about-log-item:focus-within {
  border-color: var(--c-amber);
}

.page-about .about-log-tag {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--c-amber);
  transition: color var(--dur) var(--ease);
}

.page-about .about-log-item:hover .about-log-tag {
  color: var(--c-orange);
}

.page-about .about-log-text {
  font-size: 15px;
  line-height: 1.72;
  color: var(--c-text);
}

/* ---------- 适配清单 ---------- */
.page-about .about-specs {
  list-style: none;
  margin: 30px 0 0;
  padding: 0;
  border-top: 1px solid var(--c-line);
}

.page-about .about-specs .spec-row {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  justify-content: space-between;
  gap: 6px 20px;
  padding: 14px 0;
  border-bottom: 1px solid var(--c-line);
  transition: border-color var(--dur) var(--ease);
}

.page-about .about-specs .spec-row:hover {
  border-color: var(--c-amber);
}

.page-about .about-specs .spec-name {
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.06em;
  color: var(--c-muted);
}

.page-about .about-specs .spec-state {
  font-size: 15px;
  font-weight: 500;
  line-height: 1.6;
  color: var(--c-celadon);
  text-align: right;
}

/* ---------- 图片 ---------- */
.page-about .about-figure {
  margin: 32px 0 0;
}

.page-about .about-figure img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  object-fit: cover;
  border: 1px solid var(--c-line);
  border-radius: var(--radius);
}

.page-about .about-figure figcaption {
  margin-top: 12px;
  font-family: var(--font-mono);
  font-size: 12px;
  line-height: 1.7;
  letter-spacing: 0.04em;
  color: var(--c-muted);
}

/* ---------- 收尾分流 ---------- */
.page-about .about-next {
  padding: clamp(44px, 6vw, 88px) 0 clamp(52px, 7vw, 96px);
  border-top: 1px solid var(--c-line);
  background:
    radial-gradient(90% 80% at 88% 100%, rgba(87, 183, 154, 0.08), transparent 62%),
    var(--c-dome);
}

.page-about .about-next-title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(26px, 4.6vw, 42px);
  line-height: 1.12;
  letter-spacing: -0.015em;
  color: var(--c-text);
}

.page-about .about-next-lede {
  max-width: 34em;
  margin: 20px 0 0;
  font-size: 16px;
  line-height: 1.8;
  color: var(--c-muted);
}

.page-about .about-next-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin: 30px 0 0;
}

/* ---------- 响应式 ---------- */
@media (min-width: 620px) {
  .page-about .about-br {
    display: inline;
  }
}

@media (min-width: 720px) {
  .page-about .about-roles {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .page-about .about-log-item {
    grid-template-columns: 168px minmax(0, 1fr);
    gap: 20px;
    align-items: baseline;
  }
}

@media (min-width: 760px) {
  .page-about .about-facts {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .about-fact {
    padding: 20px 18px;
  }
}

@media (min-width: 900px) {
  .page-about .about-chapter {
    display: grid;
    grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
    column-gap: clamp(32px, 5vw, 80px);
    align-items: start;
  }

  .page-about .about-body {
    margin-top: 4px;
  }

  .page-about .about-chapter h2 {
    max-width: 14ch;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-fact,
  .page-about .about-index-list a,
  .page-about .about-role,
  .page-about .about-log-item,
  .page-about .about-log-tag,
  .page-about .about-specs .spec-row,
  .page-about .breadcrumb a {
    transition: none;
  }
}