.page-about {
  --pg-accent: #FF2E88;
  --pg-blue: #00D4FF;
  background-color: var(--bg-base);
  color: var(--text-high);
  overflow-x: hidden;
}

/* ===== 顶部横幅 ===== */
.page-about .pg-hero {
  position: relative;
  min-height: clamp(540px, 86vh, 780px);
  display: flex;
  align-items: flex-end;
  overflow: hidden;
  border-bottom: 1px solid var(--line-color);
}

.page-about .pg-hero-bg {
  position: absolute;
  inset: 0;
  z-index: 1;
}

.page-about .pg-hero-bg img.pg-hero-img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
  filter: saturate(0.65) brightness(0.5) contrast(1.1);
}

.page-about .pg-hero-shade {
  position: absolute;
  inset: 0;
  background: linear-gradient(180deg, rgba(11, 14, 20, 0.2) 0%, rgba(11, 14, 20, 0.45) 45%, rgba(11, 14, 20, 0.94) 100%);
}

.page-about .pg-grid {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  z-index: 2;
  opacity: 0.8;
}

.page-about .pg-hero::after {
  content: '';
  position: absolute;
  left: 0;
  right: 0;
  top: 0;
  height: 70%;
  z-index: 3;
  background: linear-gradient(180deg, transparent, rgba(0, 212, 255, 0.08), transparent);
  pointer-events: none;
  animation: pageabout-scan-y 7s ease-in-out infinite;
}

@keyframes pageabout-scan-y {
  0%, 100% { transform: translateY(-100%); opacity: 0; }
  20%, 80% { opacity: 1; }
  50% { transform: translateY(100%); }
}

.page-about .pg-hero-content {
  position: relative;
  z-index: 4;
  width: 100%;
  max-width: var(--container-w);
  margin: 0 auto;
  padding: calc(var(--header-h) + clamp(48px, 8vw, 100px)) var(--container-pad) clamp(36px, 5vw, 56px);
}

.page-about .pg-hero-content h1 {
  font-family: var(--font-heading);
  font-size: clamp(2.1rem, 5.2vw, 4.5rem);
  line-height: 1.04;
  letter-spacing: 0.015em;
  text-transform: uppercase;
  max-width: 14em;
  margin: 18px 0 0;
  color: var(--text-high);
  text-shadow: 0 0 30px rgba(255, 46, 136, 0.25);
}

.page-about .pg-hero-lede {
  margin: 18px 0 34px;
  max-width: 46em;
  color: #C6D0E8;
  font-size: 1.02rem;
  line-height: 1.8;
}

.page-about .pg-hero-stats {
  display: flex;
  flex-wrap: wrap;
  gap: clamp(20px, 4vw, 52px);
  padding-top: 24px;
  border-top: 1px solid var(--line-color);
}

.page-about .pg-stat {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.page-about .pg-stat-num {
  font-family: var(--font-heading);
  font-size: clamp(1.8rem, 3vw, 2.6rem);
  color: var(--pg-accent);
  line-height: 1;
}

.page-about .pg-stat-label {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.12em;
  color: var(--text-dim);
  text-transform: uppercase;
}

/* ===== 面包屑 ===== */
.page-about .breadcrumb {
  max-width: var(--container-w);
  margin: 0 auto;
  padding: 20px var(--container-pad);
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--text-dim);
  border-left: 3px solid var(--pg-accent);
}

.page-about .breadcrumb a {
  color: var(--pg-blue);
  text-decoration: none;
}

.page-about .breadcrumb a:hover {
  color: var(--pg-accent);
}

.page-about .breadcrumb span {
  margin: 0 8px;
  color: var(--line-color);
}

/* ===== 档案主体 ===== */
.page-about .pg-dossier {
  max-width: var(--container-w);
  margin: 0 auto;
  padding: 8px var(--container-pad) clamp(64px, 10vw, 120px);
  display: grid;
  grid-template-columns: 1fr;
  gap: 40px 64px;
  position: relative;
}

/* 章节目录 */
.page-about .pg-toc {
  position: relative;
  border: 1px solid var(--line-color);
  background: var(--bg-surface);
  box-shadow: 6px 6px 0 rgba(0, 0, 0, 0.35);
  padding: 18px 18px 20px;
  order: 2;
}

.page-about .pg-toc::before {
  content: '';
  position: absolute;
  left: -3px;
  top: 18px;
  bottom: 18px;
  width: 3px;
  background: linear-gradient(180deg, var(--pg-blue), var(--pg-accent));
  opacity: 0.5;
}

.page-about .pg-toc .section-label {
  display: block;
  margin-bottom: 10px;
}

.page-about .pg-toc-list {
  display: flex;
  overflow-x: auto;
  gap: 4px;
  list-style: none;
  margin: 12px 0 14px;
  padding: 0;
  -webkit-overflow-scrolling: touch;
}

.page-about .pg-toc-list li {
  flex: 0 0 auto;
}

.page-about .pg-toc-list a {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 9px 12px;
  margin-right: 2px;
  border: 1px solid transparent;
  color: var(--text-high);
  text-decoration: none;
  font-size: 0.84rem;
  white-space: nowrap;
  transition: color 0.2s ease, background-color 0.2s ease, border-color 0.2s ease;
}

.page-about .pg-toc-list a:hover,
.page-about .pg-toc-list a:focus-visible {
  color: var(--pg-accent);
  border-color: var(--line-color);
  background: rgba(255, 46, 136, 0.06);
}

.page-about .pg-toc-idx {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  color: var(--pg-blue);
}

.page-about .pg-toc-note {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  line-height: 1.6;
  color: var(--text-dim);
  margin: 0 0 16px;
  letter-spacing: 0.05em;
}

.page-about .pg-toc .btn {
  width: 100%;
  justify-content: center;
}

/* 档案内容列 */
.page-about .pg-files {
  display: flex;
  flex-direction: column;
  gap: 64px;
  position: relative;
  min-width: 0;
}

/* 章节 */
.page-about .pg-chapter {
  scroll-margin-top: calc(var(--header-h) + 40px);
  position: relative;
}

.page-about .pg-chapter + .pg-chapter {
  border-top: 1px solid var(--line-color);
  padding-top: 56px;
}

.page-about .pg-chapter-head {
  display: flex;
  align-items: flex-start;
  gap: 16px;
  border-bottom: 2px solid var(--line-color);
  padding-bottom: 18px;
  margin-bottom: 30px;
}

.page-about .pg-chap-num {
  font-family: var(--font-mono);
  font-size: clamp(1.5rem, 3vw, 2.4rem);
  line-height: 1;
  color: var(--pg-accent);
  background: rgba(255, 46, 136, 0.08);
  border: 1px solid rgba(255, 46, 136, 0.28);
  border-left-width: 4px;
  padding: 7px 10px;
  white-space: nowrap;
}

.page-about .pg-chapter-head h2 {
  font-family: var(--font-heading);
  font-size: clamp(1.55rem, 3vw, 2.4rem);
  line-height: 1.12;
  text-transform: uppercase;
  letter-spacing: 0.02em;
  margin: 8px 0 0;
  color: var(--text-high);
}

.page-about .pg-chapter-body p {
  font-size: 0.95rem;
  line-height: 1.85;
  color: #AEB9CF;
  margin: 0 0 16px;
  max-width: 44em;
}

.page-about .pg-note {
  font-family: var(--font-mono);
  font-size: 0.82rem;
  line-height: 1.7;
  color: var(--text-dim);
  border-left: 2px solid #FF8A00;
  padding-left: 14px;
  margin-top: 22px;
}

.page-about .pg-inline-scan {
  position: relative;
  height: 2px;
  margin: 26px 0 16px;
  background: rgba(255, 46, 136, 0.08);
  overflow: hidden;
}

.page-about .pg-inline-scan::after {
  content: '';
  position: absolute;
  top: 0;
  left: -30%;
  width: 24%;
  height: 100%;
  background: linear-gradient(90deg, transparent, var(--pg-accent));
  animation: pageabout-scanrun 2.4s linear infinite;
}

@keyframes pageabout-scanrun {
  0% { left: -30%; opacity: 0.4; }
  15% { opacity: 1; }
  85% { opacity: 1; }
  100% { left: 110%; opacity: 0.4; }
}

/* 运营主体卡片 */
.page-about .pg-entity-card {
  margin: 26px 0 6px;
  border: 1px solid var(--line-color);
  background: var(--bg-surface);
  box-shadow: 8px 8px 0 rgba(0, 0, 0, 0.25);
}

.page-about .pg-entity-row {
  display: grid;
  grid-template-columns: 96px 1fr;
  border-bottom: 1px solid var(--line-color);
  font-size: 0.88rem;
}

.page-about .pg-entity-row:last-child {
  border-bottom: none;
}

.page-about .pg-entity-label {
  display: flex;
  align-items: center;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--pg-blue);
  padding: 14px 12px;
  border-right: 1px solid var(--line-color);
}

.page-about .pg-entity-value {
  display: flex;
  align-items: center;
  padding: 14px 16px;
  color: var(--text-high);
}

/* 流程图片 */
.page-about .pg-flow-img {
  width: 100%;
  height: auto;
  max-width: 800px;
  margin: 28px auto 24px;
  display: block;
  border: 1px solid var(--line-color);
  box-shadow: 8px 8px 0 rgba(0, 0, 0, 0.25);
}

/* 演进时间轴：使用共享 timeline 类，此处仅补充间距 */
.page-about .pg-evolve-timeline {
  margin: 20px 0 28px;
}

.page-about .pg-evolve-timeline .timeline-item span {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: #FF8A00;
}

.page-about .pg-evolve-timeline .timeline-item p {
  font-size: 0.88rem;
  margin: 4px 0 0;
}

/* 更新规则 */
.page-about .pg-rule-list {
  list-style: none;
  margin: 28px 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: 1fr;
  gap: 14px;
}

.page-about .pg-rule-list li {
  display: flex;
  align-items: center;
  gap: 12px;
  border: 1px solid var(--line-color);
  background: var(--bg-surface);
  padding: 14px 16px;
  font-size: 0.88rem;
  line-height: 1.6;
  color: #AEB9CF;
}

.page-about .pg-rule-week {
  background: rgba(255, 138, 0, 0.12);
  color: #FF8A00;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  padding: 4px 8px;
  white-space: nowrap;
  border-radius: 2px;
}

/* 运营原则 */
.page-about .pg-principle {
  display: grid;
  grid-template-columns: 1fr;
  gap: 24px;
  margin: 40px 0 0;
  align-items: center;
  border-top: 1px dashed var(--line-color);
  padding-top: 36px;
}

.page-about .pg-principle-text {
  border-left: 3px solid var(--pg-blue);
  padding-left: 18px;
}

.page-about .pg-principle-text h3 {
  font-family: var(--font-heading);
  font-size: 1.4rem;
  line-height: 1.2;
  margin: 10px 0 12px;
  text-transform: uppercase;
  color: var(--text-high);
}

.page-about .pg-principle-text p {
  font-size: 0.92rem;
  line-height: 1.8;
  color: #AEB9CF;
  margin: 0;
  max-width: 40em;
}

.page-about .pg-principle-media img {
  width: 100%;
  height: auto;
  max-width: 460px;
  display: block;
  border: 1px solid var(--line-color);
  box-shadow: 8px 8px 0 rgba(0, 0, 0, 0.25);
  object-fit: cover;
}

/* 回访支持网格 */
.page-about .pg-return-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 16px;
  margin-top: 28px;
}

.page-about .pg-return-card {
  border: 1px solid var(--line-color);
  border-top: 3px solid var(--pg-accent);
  background: var(--bg-surface);
  box-shadow: 4px 4px 0 rgba(0, 0, 0, 0.25);
  padding: 18px 18px 16px;
}

.page-about .pg-return-card h3 {
  font-family: var(--font-heading);
  font-size: 1.08rem;
  text-transform: uppercase;
  letter-spacing: 0.02em;
  color: var(--text-high);
  margin: 0 0 8px;
}

.page-about .pg-return-card p {
  font-size: 0.85rem;
  line-height: 1.7;
  color: #9AA6BD;
  margin: 0;
}

/* 联系网格 */
.page-about .pg-contact-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 14px;
  margin: 26px 0 18px;
}

.page-about .pg-contact-card {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  border: 1px solid var(--line-color);
  background: var(--bg-surface);
  padding: 18px 20px;
  text-decoration: none;
  color: var(--text-high);
  transition: border-color 0.2s ease, box-shadow 0.2s ease, transform 0.2s ease;
}

.page-about a.pg-contact-card:hover,
.page-about a.pg-contact-card:focus-visible {
  border-color: var(--pg-accent);
  box-shadow: 4px 4px 0 rgba(255, 46, 136, 0.2);
  transform: translate(-1px, -1px);
}

.page-about .pg-contact-key {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--pg-blue);
  flex: 0 0 auto;
}

.page-about .pg-contact-val {
  font-family: var(--font-mono);
  font-size: 0.86rem;
  color: var(--text-high);
  text-align: right;
  word-break: break-all;
}

/* 底部链接带 */
.page-about .pg-footer-links {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 12px;
  margin-top: 48px;
  padding-top: 32px;
  border-top: 2px solid var(--line-color);
}

.page-about .pg-footer-link-card {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  border: 1px solid var(--line-color);
  background: var(--bg-surface);
  color: var(--text-high);
  text-decoration: none;
  padding: 18px 12px;
  font-family: var(--font-heading);
  font-size: 0.95rem;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  transition: border-color 0.2s ease, color 0.2s ease, background-color 0.2s ease;
}

.page-about .pg-footer-link-card:hover,
.page-about .pg-footer-link-card:focus-visible {
  border-color: var(--pg-blue);
  color: var(--pg-blue);
  background: rgba(0, 212, 255, 0.06);
}

/* ===== 桌面端断点 ===== */
@media (min-width: 880px) {
  .page-about .pg-dossier {
    grid-template-columns: 220px minmax(0, 1fr);
    gap: 64px;
    align-items: start;
  }

  .page-about .pg-toc {
    order: 1;
    position: sticky;
    top: calc(var(--header-h) + 28px);
    z-index: 5;
  }

  .page-about .pg-toc-list {
    display: block;
    overflow: visible;
    margin: 16px 0 18px;
  }

  .page-about .pg-toc-list li {
    border-bottom: 1px solid var(--line-color);
  }

  .page-about .pg-toc-list a {
    justify-content: flex-start;
    border: none;
    border-left: 2px solid transparent;
    border-radius: 0;
    margin: 0;
    padding: 12px 2px;
    white-space: normal;
  }

  .page-about .pg-toc-list a:hover {
    border-left-color: var(--pg-accent);
    border: none;
    border-left: 2px solid var(--pg-accent);
    background: none;
  }

  .page-about .pg-toc-list a:hover,
  .page-about .pg-toc-list a:focus-visible {
    background: none;
    border-left: 2px solid var(--pg-accent);
    color: var(--text-high);
  }

  .page-about .pg-toc-list a:hover .pg-toc-idx {
    color: var(--pg-accent);
  }

  .page-about .pg-toc-note {
    margin-bottom: 18px;
  }

  .page-about .pg-files {
    order: 2;
    gap: 72px;
  }

  .page-about .pg-files::before {
    content: '';
    position: absolute;
    left: -32px;
    top: 0;
    bottom: 0;
    width: 1px;
    background: repeating-linear-gradient(180deg, var(--line-color) 0, var(--line-color) 5px, transparent 5px, transparent 10px);
    opacity: 0.6;
  }

  .page-about .pg-chapter + .pg-chapter {
    padding-top: 64px;
  }

  .page-about .pg-return-grid {
    grid-template-columns: 1fr 1fr;
  }

  .page-about .pg-contact-grid {
    grid-template-columns: repeat(3, 1fr);
  }

  .page-about .pg-contact-card {
    flex-direction: column;
    align-items: flex-start;
    gap: 8px;
  }

  .page-about .pg-contact-val {
    text-align: left;
    word-break: normal;
  }

  .page-about .pg-footer-links {
    grid-template-columns: repeat(4, 1fr);
  }

  .page-about .pg-principle {
    grid-template-columns: minmax(0, 1fr) 260px;
    gap: 40px;
  }
}

/* ===== 大屏优化 ===== */
@media (min-width: 1200px) {
  .page-about .pg-dossier {
    grid-template-columns: 260px minmax(0, 1fr);
    gap: 88px;
  }

  .page-about .pg-files::before {
    left: -44px;
  }

  .page-about .pg-chapter-head {
    gap: 20px;
  }

  .page-about .pg-principle {
    grid-template-columns: minmax(0, 1fr) 320px;
  }

  .page-about .pg-principle-media img {
    max-width: 320px;
    margin-left: auto;
  }
}