.page-about {
  --about-rail-w: 202px;
  --about-glass: rgba(237, 242, 238, .06);
  --about-hair: rgba(185, 200, 192, .2);
  --about-soft: rgba(247, 250, 247, .78);
  overflow-x: clip;
  background:
    radial-gradient(900px 520px at 88% -4%, rgba(58, 32, 89, .5), transparent 60%),
    radial-gradient(760px 480px at 4% 34%, rgba(12, 58, 50, .55), transparent 62%),
    linear-gradient(180deg, var(--ink-900) 0%, #041b18 55%, var(--ink-900) 100%);
  color: var(--ivory);
}

/* 面包屑 */
.page-about .breadcrumb ol {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  margin: 0;
  padding: 22px 0 4px;
  list-style: none;
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: .04em;
}
.page-about .breadcrumb li + li::before {
  content: "/";
  margin-right: 8px;
  color: var(--muted);
}
.page-about .breadcrumb a {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: border-color .18s var(--ease);
}
.page-about .breadcrumb a:hover {
  border-bottom-color: var(--cyan);
}
.page-about .breadcrumb [aria-current="page"] {
  color: rgba(247, 250, 247, .66);
}

/* 外壳：左时间轴 + 右编年流 */
.page-about .about-shell {
  display: grid;
  grid-template-columns: 1fr;
  gap: 30px;
  align-items: start;
  padding-bottom: 84px;
}
@media (min-width: 1040px) {
  .page-about .about-shell {
    grid-template-columns: var(--about-rail-w) minmax(0, 1fr);
    gap: 56px;
  }
}

/* 左侧时间轴 */
.page-about .about-rail {
  position: relative;
  min-width: 0;
}
.page-about .rail-title {
  margin: 0 0 10px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: .18em;
  text-transform: uppercase;
  color: rgba(185, 200, 192, .7);
}
.page-about .rail-list {
  display: flex;
  gap: 8px;
  margin: 0;
  padding: 2px 2px 12px;
  list-style: none;
  overflow-x: auto;
  scrollbar-width: thin;
}
.page-about .rail-item {
  flex: 0 0 auto;
}
.page-about .rail-link {
  position: relative;
  display: block;
  padding: 8px 14px;
  border-radius: 999px;
  font-family: var(--font-mono);
  font-size: 13px;
  white-space: nowrap;
  color: rgba(247, 250, 247, .6);
  text-decoration: none;
  background: rgba(237, 242, 238, .05);
  transition: color .18s var(--ease), background-color .18s var(--ease);
}
.page-about .rail-link:hover,
.page-about .rail-link:focus-visible {
  color: var(--cyan-soft);
  background: rgba(47, 227, 198, .1);
}
.page-about .rail-link:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 2px;
}
.page-about .rail-link[aria-current],
.page-about .rail-link.is-active {
  color: var(--ink-900);
  background: var(--cyan);
  font-weight: 500;
}

@media (min-width: 1040px) {
  .page-about .about-rail {
    position: sticky;
    top: calc(var(--header-h) + 26px);
  }
  .page-about .rail-list {
    display: block;
    overflow: visible;
    padding: 4px 0 4px 0;
    border-left: 1px solid rgba(47, 227, 198, .22);
  }
  .page-about .rail-item + .rail-item {
    margin-top: 4px;
  }
  .page-about .rail-link {
    border-radius: 0 999px 999px 0;
    padding: 10px 16px 10px 22px;
    background: transparent;
  }
  .page-about .rail-link::before {
    content: "";
    position: absolute;
    left: -5px;
    top: 50%;
    width: 9px;
    height: 9px;
    transform: translateY(-50%);
    border-radius: 50%;
    background: var(--ink-900);
    border: 1px solid rgba(185, 200, 192, .5);
    transition: background-color .18s var(--ease), border-color .18s var(--ease), box-shadow .18s var(--ease);
  }
  .page-about .rail-link:hover {
    background: rgba(47, 227, 198, .08);
    color: var(--cyan-soft);
  }
  .page-about .rail-link[aria-current],
  .page-about .rail-link.is-active {
    background: rgba(47, 227, 198, .14);
    color: var(--cyan);
  }
  .page-about .rail-link[aria-current]::before,
  .page-about .rail-link.is-active::before {
    background: var(--cyan);
    border-color: var(--cyan);
    box-shadow: 0 0 0 4px rgba(47, 227, 198, .16);
  }
}

/* 内容流通用 */
.page-about .about-flow {
  min-width: 0;
  display: grid;
  gap: 8px;
}
.page-about .eyebrow {
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: .18em;
  color: var(--cyan);
  margin: 0;
}

/* 首屏 */
.page-about .about-hero {
  padding: 6px 0 34px;
}
.page-about .about-hero h1 {
  margin: 14px 0 18px;
  font-family: var(--font-display);
  font-size: clamp(32px, 6vw, 58px);
  font-weight: 700;
  line-height: 1.06;
  letter-spacing: -.01em;
  color: var(--ivory);
  max-width: 22ch;
}
.page-about .about-lead {
  margin: 0 0 30px;
  max-width: 64ch;
  font-size: 16.5px;
  line-height: 1.9;
  color: var(--about-soft);
}
.page-about .about-hero-figure {
  margin: 0;
}

/* 媒体画框补充 */
.page-about .media-frame {
  position: relative;
  border-radius: var(--radius);
  overflow: hidden;
  border: 1px solid rgba(47, 227, 198, .16);
  background: rgba(12, 58, 50, .5);
}
.page-about .media-frame img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  object-fit: cover;
  filter: saturate(.82) hue-rotate(-6deg);
}
.page-about .media-caption {
  display: block;
  padding: 10px 14px;
  font-family: var(--font-mono);
  font-size: 12px;
  line-height: 1.7;
  color: rgba(247, 250, 247, .6);
  background: rgba(6, 35, 31, .72);
  border-top: 1px solid var(--about-hair);
}

/* 章节 */
.page-about .flow-section {
  position: relative;
  padding: 44px 0 6px;
  scroll-margin-top: calc(var(--header-h) + 22px);
}
.page-about .flow-section h2 {
  margin: 10px 0 16px;
  font-family: var(--font-display);
  font-size: clamp(25px, 3.6vw, 36px);
  font-weight: 600;
  line-height: 1.16;
  letter-spacing: -.005em;
  color: var(--ivory);
  max-width: 26ch;
}
.page-about .flow-section p {
  margin: 0 0 14px;
  max-width: 66ch;
  font-size: 16px;
  line-height: 1.9;
  color: var(--about-soft);
}
.page-about .flow-section a {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(47, 227, 198, .45);
  transition: color .18s var(--ease), border-color .18s var(--ease);
}
.page-about .flow-section a:hover {
  color: var(--cyan-soft);
  border-bottom-color: var(--cyan-soft);
}

/* 阶段面板：靛紫与墨绿交替 */
.page-about .phase-track {
  display: grid;
  gap: 14px;
  margin: 24px 0 0;
}
.page-about .phase {
  position: relative;
  padding: 24px 24px 22px 28px;
  border-radius: var(--radius);
  overflow: hidden;
  background: linear-gradient(135deg, rgba(12, 58, 50, .94), rgba(6, 35, 31, .8));
  border: 1px solid rgba(47, 227, 198, .16);
  box-shadow: 0 16px 34px rgba(3, 16, 14, .4);
}
.page-about .phase::after {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 4px;
  background: linear-gradient(180deg, var(--cyan) 0%, rgba(47, 227, 198, 0) 88%);
}
.page-about .phase--violet {
  background: linear-gradient(135deg, rgba(58, 32, 89, .92), rgba(6, 35, 31, .78));
  border-color: rgba(140, 246, 228, .2);
}
.page-about .phase--violet::after {
  background: linear-gradient(180deg, var(--amber) 0%, rgba(255, 154, 77, 0) 88%);
}
.page-about .phase-year {
  display: inline-block;
  padding: 4px 11px;
  border: 1px solid rgba(47, 227, 198, .42);
  border-radius: 4px;
  transform: skewX(-9deg);
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: .08em;
  color: var(--cyan);
}
.page-about .phase--violet .phase-year {
  border-color: rgba(255, 154, 77, .5);
  color: var(--amber);
}
.page-about .phase-year > span {
  display: inline-block;
  transform: skewX(9deg);
}
.page-about .phase h3 {
  margin: 14px 0 8px;
  font-family: var(--font-display);
  font-size: 22px;
  font-weight: 600;
  line-height: 1.25;
  color: var(--ivory);
}
.page-about .phase p {
  margin: 0 0 10px;
  max-width: 58ch;
  font-size: 15.5px;
  line-height: 1.85;
  color: rgba(247, 250, 247, .76);
}
.page-about .phase-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 20px;
  margin: 14px 0 0;
  padding-top: 12px;
  border-top: 1px dashed rgba(185, 200, 192, .26);
  font-family: var(--font-mono);
  font-size: 12.5px;
  color: rgba(247, 250, 247, .58);
}

/* 筛选角度 */
.page-about .filter-list {
  display: grid;
  gap: 12px;
  margin: 22px 0 18px;
  padding: 0;
  list-style: none;
}
@media (min-width: 720px) {
  .page-about .filter-list {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}
.page-about .filter-list li {
  padding: 18px 18px 20px;
  border-radius: var(--radius);
  background: var(--about-glass);
  border: 1px solid var(--about-hair);
  border-left: 3px solid rgba(47, 227, 198, .55);
  transition: background-color .18s var(--ease), border-color .18s var(--ease);
}
.page-about .filter-list li:hover {
  background: rgba(47, 227, 198, .1);
  border-left-color: var(--cyan);
}
.page-about .filter-key {
  display: block;
  margin-bottom: 8px;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: .12em;
  color: var(--cyan);
}
.page-about .filter-desc {
  display: block;
  font-size: 15px;
  line-height: 1.82;
  color: var(--about-soft);
}
.page-about .filter-note {
  margin-top: 4px;
}

/* 档案条目区 */
.page-about .entry-figure {
  margin: 22px 0 26px;
}
.page-about .entry-stack {
  display: grid;
  gap: 14px;
}
.page-about .entry {
  position: relative;
  padding: 20px 22px 18px;
  border-radius: var(--radius);
  background: linear-gradient(160deg, rgba(237, 242, 238, .1), rgba(6, 35, 31, .62));
  border: 1px solid var(--about-hair);
  backdrop-filter: blur(6px);
}
.page-about .entry::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 74px;
  height: 3px;
  background: var(--cyan);
  transform: skewX(-28deg);
  transform-origin: left top;
}
.page-about .entry-title {
  margin: 4px 0 8px;
  font-family: var(--font-display);
  font-size: 21px;
  font-weight: 600;
  line-height: 1.25;
  color: var(--ivory);
}
.page-about .entry-sum {
  margin: 0;
  max-width: 58ch;
  font-size: 15px;
  line-height: 1.82;
  color: rgba(247, 250, 247, .74);
}
.page-about .entry-toggle {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin-top: 14px;
  padding: 7px 16px;
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: .06em;
  color: var(--cyan);
  background: transparent;
  border: 1px solid rgba(47, 227, 198, .45);
  border-radius: 999px;
  cursor: pointer;
  transition: background-color .18s var(--ease), color .18s var(--ease), border-color .18s var(--ease);
}
.page-about .entry-toggle:hover {
  background: rgba(47, 227, 198, .14);
}
.page-about .entry-toggle:focus-visible {
  outline: 2px solid var(--cyan-soft);
  outline-offset: 2px;
}
.page-about .entry-toggle[aria-expanded="true"] {
  background: var(--cyan);
  border-color: var(--cyan);
  color: var(--ink-900);
}
.page-about .entry-panel {
  display: block;
  margin-top: 14px;
  padding-top: 14px;
  border-top: 1px dashed rgba(185, 200, 192, .26);
}
.page-about .entry-panel[hidden],
.page-about .entry-panel.is-collapsed {
  display: none;
}
.page-about .entry-panel p {
  margin: 0;
  max-width: 62ch;
  font-size: 15px;
  line-height: 1.86;
  color: rgba(247, 250, 247, .8);
}

/* 浏览路径 */
.page-about .path-list {
  display: grid;
  gap: 12px;
  margin: 22px 0 18px;
  padding: 0;
  list-style: none;
  counter-reset: none;
}
.page-about .path-list li {
  display: grid;
  grid-template-columns: 46px minmax(0, 1fr);
  align-items: start;
  gap: 14px;
  padding: 16px 18px;
  border-radius: var(--radius);
  background: rgba(12, 58, 50, .52);
  border: 1px solid rgba(47, 227, 198, .14);
}
.page-about .path-num {
  font-family: var(--font-mono);
  font-size: 20px;
  font-weight: 500;
  line-height: 1.2;
  color: var(--flame);
}
.page-about .path-list p {
  margin: 0;
  font-size: 15.5px;
  line-height: 1.82;
  color: var(--about-soft);
}
.page-about .cross-note {
  margin-top: 6px;
}

/* 规模仪表 */
.page-about .about-stats {
  display: grid;
  gap: 12px;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  margin: 22px 0 20px;
}
@media (min-width: 860px) {
  .page-about .about-stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}
.page-about .about-stats .stat {
  position: relative;
  padding: 18px 16px 16px;
  border-radius: var(--radius);
  background: linear-gradient(180deg, rgba(237, 242, 238, .09), rgba(6, 35, 31, .55));
  border: 1px solid var(--about-hair);
  overflow: hidden;
}
.page-about .about-stats .stat::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  height: 2px;
  background: linear-gradient(90deg, var(--cyan), rgba(47, 227, 198, 0));
}
.page-about .about-stats .stat-value {
  display: block;
  font-family: var(--font-mono);
  font-size: 30px;
  font-weight: 500;
  line-height: 1.1;
  letter-spacing: -.01em;
  color: var(--cyan);
}
.page-about .about-stats .stat:nth-child(3) .stat-value,
.page-about .about-stats .stat:nth-child(4) .stat-value {
  color: var(--amber);
}
.page-about .about-stats .stat-label {
  display: block;
  margin-top: 8px;
  font-size: 13px;
  line-height: 1.6;
  color: rgba(247, 250, 247, .68);
}

/* 团队角色 */
.page-about .team-figure {
  margin: 20px 0 26px;
}
.page-about .role-list {
  display: grid;
  gap: 14px;
  margin: 0 0 18px;
  padding: 0;
  list-style: none;
}
@media (min-width: 780px) {
  .page-about .role-list {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}
.page-about .role {
  padding: 20px 18px 22px;
  border-radius: var(--radius);
  background: rgba(58, 32, 89, .34);
  border: 1px solid rgba(140, 246, 228, .18);
}
.page-about .role:nth-child(2) {
  background: rgba(12, 58, 50, .72);
  border-color: rgba(47, 227, 198, .2);
}
.page-about .role:nth-child(3) {
  background: rgba(92, 30, 51, .38);
  border-color: rgba(255, 154, 77, .22);
}
.page-about .role h3 {
  margin: 0 0 10px;
  font-family: var(--font-display);
  font-size: 20px;
  font-weight: 600;
  line-height: 1.25;
  color: var(--ivory);
}
.page-about .role p {
  margin: 0;
  font-size: 15px;
  line-height: 1.82;
  color: var(--about-soft);
}
.page-about .team-note {
  margin-top: 4px;
}

/* 窄屏修饰 */
@media (max-width: 560px) {
  .page-about .phase {
    padding: 20px 18px 18px 22px;
  }
  .page-about .path-list li {
    grid-template-columns: 36px minmax(0, 1fr);
    gap: 10px;
    padding: 14px 14px;
  }
  .page-about .about-stats .stat-value {
    font-size: 26px;
  }
  .page-about .about-shell {
    padding-bottom: 60px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about * {
    transition-duration: .01ms !important;
  }
}