.page-about {
  --about-text: rgba(242, 237, 228, 0.88);
  --about-soft: rgba(242, 237, 228, 0.68);
}

/* ---- Hero ---- */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  padding: 40px 0 48px;
  background-color: var(--bg);
  background-image: repeating-linear-gradient(90deg, var(--line-soft) 0 1px, transparent 1px 24px);
  border-bottom: 1px solid var(--line);
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  top: -22%;
  right: -14%;
  width: 64%;
  height: 148%;
  background: linear-gradient(155deg, rgba(63, 224, 200, 0.14), rgba(63, 224, 200, 0) 62%);
  transform: rotate(-6deg);
  pointer-events: none;
}

.page-about .about-hero-inner {
  position: relative;
  z-index: 1;
}

.page-about .about-kicker {
  margin: 20px 0 14px;
  font-size: var(--f12);
  letter-spacing: 0.2em;
  color: var(--orange);
  text-transform: uppercase;
}

.page-about .about-title {
  margin: 0 0 20px;
  font-family: var(--sans);
  font-weight: 900;
  font-size: 28px;
  line-height: 1.18;
  letter-spacing: -0.02em;
  color: var(--paper);
  max-width: 24ch;
}

.page-about .about-lead {
  margin: 0 0 32px;
  max-width: 66ch;
  font-size: var(--f16);
  line-height: 1.85;
  color: var(--about-soft);
}

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

.page-about .about-stat {
  margin: 0;
  padding: 16px 14px;
  background: var(--bg-2);
}

.page-about .about-stat-label {
  margin: 0 0 8px;
  font-size: var(--f12);
  letter-spacing: 0.1em;
  color: var(--ash);
}

.page-about .about-stat-num {
  display: flex;
  align-items: baseline;
  gap: 6px;
  margin: 0;
  font-size: var(--f28);
  line-height: 1.05;
  color: var(--cyan);
}

.page-about .about-stat-unit {
  font-size: var(--f12);
  letter-spacing: 0.04em;
  color: var(--ash);
}

/* ---- Shell：左目录 + 右长文 ---- */
.page-about .about-shell {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 28px;
  padding: 40px 0 64px;
}

/* ---- 章节目录 ---- */
.page-about .about-index-head {
  margin: 0 0 12px;
  font-size: var(--f12);
  letter-spacing: 0.22em;
  color: var(--ash);
}

.page-about .about-index-list {
  display: flex;
  gap: 8px;
  margin: 0;
  padding: 0 0 8px;
  list-style: none;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  scrollbar-width: thin;
}

.page-about .index-link {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 8px 12px;
  border: 1px solid var(--line);
  color: var(--ash);
  font-size: var(--f14);
  text-decoration: none;
  white-space: nowrap;
  transition: color var(--t-fast), border-color var(--t-fast), background var(--t-fast);
}

.page-about .index-link:hover {
  color: var(--cyan-soft);
  border-color: var(--cyan-line);
}

.page-about .index-link[aria-current="true"] {
  color: var(--cyan);
  border-color: var(--cyan-line);
}

.page-about .index-num {
  font-size: var(--f12);
  color: var(--orange);
}

/* ---- 章节 ---- */
.page-about .about-chapter {
  padding: 28px 0 56px;
  border-top: 1px solid var(--line);
  scroll-margin-top: calc(var(--band-h) + 32px);
}

.page-about .about-stream > .about-chapter:first-child {
  border-top: 0;
  padding-top: 0;
}

.page-about .about-chapter-head {
  display: flex;
  align-items: center;
  gap: 14px;
  margin-bottom: 22px;
  padding-bottom: 16px;
  border-bottom: 1px solid var(--line-soft);
}

.page-about .about-num {
  flex: none;
  font-size: 72px;
  line-height: 0.78;
  letter-spacing: -0.05em;
  color: rgba(63, 224, 200, 0.12);
  -webkit-text-stroke: 1px rgba(63, 224, 200, 0.75);
}

.page-about .about-chapter-meta {
  display: flex;
  align-items: center;
  gap: 14px;
  min-width: 0;
}

.page-about .about-chapter-title {
  margin: 0;
  font-size: var(--f20);
  font-weight: 700;
  letter-spacing: -0.01em;
  color: var(--paper);
}

.page-about .about-chapter-note {
  margin: 0;
  max-height: 58px;
  overflow: hidden;
  font-size: var(--f12);
  letter-spacing: 0.22em;
  color: var(--clay);
  white-space: nowrap;
  writing-mode: vertical-rl;
}

.page-about .about-body p {
  max-width: 68ch;
  margin: 0 0 16px;
  font-size: var(--f16);
  line-height: 1.85;
  color: var(--about-text);
}

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

/* ---- 时间线 ---- */
.page-about .tl-scroll {
  margin-top: 28px;
  padding: 32px 0 14px;
  overflow-x: auto;
  overflow-y: hidden;
  -webkit-overflow-scrolling: touch;
  scrollbar-width: thin;
  border-top: 1px solid var(--line-soft);
}

.page-about .tl {
  display: flex;
  min-width: max-content;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .tl-item {
  position: relative;
  flex: 0 0 236px;
  width: 236px;
  padding: 26px 26px 0 0;
}

.page-about .tl-item::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 1px;
  background: var(--line);
}

.page-about .tl-item:last-child::before {
  right: 26px;
}

.page-about .tl-dot {
  position: absolute;
  top: -4px;
  left: 0;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--cyan);
  box-shadow: 0 0 0 4px rgba(63, 224, 200, 0.14);
}

.page-about .tl-year {
  display: block;
  margin-bottom: 8px;
  font-size: var(--f20);
  letter-spacing: 0.04em;
  color: var(--orange);
}

.page-about .tl-title {
  margin: 0 0 8px;
  font-size: var(--f16);
  font-weight: 700;
  line-height: 1.5;
  color: var(--paper);
}

.page-about .tl-text {
  margin: 0;
  font-size: var(--f14);
  line-height: 1.75;
  color: var(--ash);
}

/* ---- 图片 ---- */
.page-about .about-figure {
  margin: 28px 0 0;
  background: var(--bg-2);
  border: 1px solid var(--line);
}

.page-about .about-figure-accent {
  border-color: var(--cyan-line);
}

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

.page-about .about-figure figcaption {
  padding: 12px 16px;
  border-top: 1px solid var(--line);
  font-size: var(--f12);
  line-height: 1.75;
  color: var(--ash);
}

/* ---- 流程 ---- */
.page-about .flow {
  display: grid;
  gap: 1px;
  margin: 26px 0 0;
  padding: 0;
  list-style: none;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .flow-step {
  padding: 20px 18px;
  background: var(--bg-2);
  transition: background var(--t-base);
}

.page-about .flow-step:hover {
  background: rgba(63, 224, 200, 0.06);
}

.page-about .flow-num {
  display: block;
  margin-bottom: 10px;
  font-size: var(--f12);
  letter-spacing: 0.2em;
  color: var(--orange);
}

.page-about .flow-title {
  margin: 0 0 8px;
  font-size: var(--f16);
  font-weight: 700;
  color: var(--paper);
}

.page-about .flow-text {
  margin: 0;
  font-size: var(--f14);
  line-height: 1.78;
  color: var(--ash);
}

/* ---- 团队分工 ---- */
.page-about .team-total {
  margin: 24px 0 12px;
  font-size: var(--f14);
  color: var(--about-soft);
}

.page-about .team-total strong {
  font-size: var(--f20);
  color: var(--cyan);
  margin: 0 4px;
}

.page-about .team-bar {
  display: flex;
  flex-direction: column;
  border: 1px solid var(--line);
  background: var(--bg-2);
}

.page-about .team-seg {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  width: 100%;
  padding: 14px 16px;
  border-bottom: 1px solid var(--line);
  cursor: default;
  outline: none;
  transition: background var(--t-fast);
}

.page-about .team-seg:last-child {
  border-bottom: 0;
}

.page-about .team-seg:hover,
.page-about .team-seg:focus-visible {
  background: rgba(63, 224, 200, 0.1);
}

.page-about .team-seg-num {
  font-size: var(--f20);
  line-height: 1;
  color: var(--cyan);
}

.page-about .team-seg-label {
  flex: 1;
  font-size: var(--f14);
  color: var(--paper);
}

.page-about .team-seg-desc {
  position: absolute;
  top: calc(100% + 8px);
  left: 0;
  z-index: 6;
  width: 260px;
  max-width: 80vw;
  padding: 12px 14px;
  border: 1px solid var(--cyan-line);
  background: var(--deep);
  color: var(--paper);
  font-size: var(--f12);
  line-height: 1.7;
  opacity: 0;
  visibility: hidden;
  transform: translateY(6px);
  transition: opacity var(--t-base), transform var(--t-base), visibility var(--t-base);
  pointer-events: none;
}

.page-about .team-seg:hover .team-seg-desc,
.page-about .team-seg:focus-visible .team-seg-desc {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.page-about .team-seg:last-child .team-seg-desc {
  left: auto;
  right: 0;
}

/* ---- 原则 ---- */
.page-about .principle-list {
  display: grid;
  gap: 22px;
  margin: 26px 0 0;
  padding: 0;
  list-style: none;
}

.page-about .principle {
  padding: 4px 0 4px 20px;
  border-left: 2px solid var(--line);
  transition: border-color var(--t-base);
}

.page-about .principle:hover {
  border-left-color: var(--cyan);
}

.page-about .principle-title {
  margin: 0 0 8px;
  font-size: var(--f20);
  font-weight: 700;
  color: var(--paper);
}

.page-about .principle-text {
  margin: 0;
  font-size: var(--f14);
  line-height: 1.78;
  color: var(--ash);
}

/* ---- 合作 ---- */
.page-about .partner-grid {
  display: grid;
  gap: 1px;
  margin: 26px 0 0;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .partner-item {
  padding: 20px 18px;
  background: var(--bg-2);
}

.page-about .partner-item-wide {
  background: linear-gradient(140deg, rgba(63, 224, 200, 0.12), rgba(7, 26, 22, 0) 70%), var(--bg-2);
}

.page-about .partner-num {
  display: block;
  margin-bottom: 6px;
  font-size: var(--f28);
  line-height: 1;
  color: var(--orange);
  letter-spacing: -0.02em;
}

.page-about .partner-title {
  margin: 0 0 8px;
  font-size: var(--f16);
  font-weight: 700;
  color: var(--paper);
}

.page-about .partner-text {
  margin: 0;
  font-size: var(--f14);
  line-height: 1.75;
  color: var(--ash);
}

/* ---- 站内跳转 ---- */
.page-about .about-routes {
  margin-top: 32px;
  padding-top: 24px;
  border-top: 1px solid var(--line-soft);
}

.page-about .about-routes-text {
  margin: 0 0 14px;
  font-size: var(--f14);
  color: var(--about-soft);
}

.page-about .route-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .about-link {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding-bottom: 2px;
  border-bottom: 1px solid var(--cyan-line);
  color: var(--cyan);
  font-size: var(--f14);
  text-decoration: none;
  transition: color var(--t-fast), border-color var(--t-fast);
}

.page-about .about-link::after {
  content: "→";
  font-family: var(--mono);
  font-size: var(--f12);
}

.page-about .about-link:hover {
  color: var(--cyan-soft);
  border-color: var(--cyan-soft);
}

/* ---- 收尾 ---- */
.page-about .about-closing {
  position: relative;
  margin-top: 40px;
  padding: 28px 22px;
  background: linear-gradient(135deg, rgba(255, 138, 61, 0.1), rgba(7, 26, 22, 0) 62%), var(--bg-2);
  border: 1px solid var(--clay);
  overflow: hidden;
}

.page-about .about-closing::before {
  content: "";
  position: absolute;
  top: -30%;
  left: -10%;
  width: 46%;
  height: 160%;
  background: linear-gradient(160deg, rgba(255, 138, 61, 0.12), rgba(255, 138, 61, 0) 70%);
  transform: rotate(6deg);
  pointer-events: none;
}

.page-about .closing-title {
  position: relative;
  margin: 0 0 10px;
  font-size: var(--f20);
  font-weight: 700;
  line-height: 1.5;
  color: var(--paper);
}

.page-about .closing-text {
  position: relative;
  margin: 0 0 20px;
  max-width: 60ch;
  font-size: var(--f14);
  line-height: 1.78;
  color: var(--about-soft);
}

.page-about .closing-actions {
  position: relative;
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

/* ---- 740px ---- */
@media (min-width: 740px) {
  .page-about .about-hero {
    padding: 56px 0 64px;
  }

  .page-about .about-title {
    font-size: 44px;
    max-width: 22ch;
  }

  .page-about .about-stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

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

  .page-about .about-num {
    font-size: 120px;
  }

  .page-about .about-chapter-head {
    gap: 20px;
    margin-bottom: 28px;
  }

  .page-about .about-chapter-title {
    font-size: var(--f28);
  }

  .page-about .about-chapter-note {
    max-height: 76px;
  }

  .page-about .about-chapter {
    padding: 36px 0 88px;
  }

  .page-about .flow {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .page-about .principle-list {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 26px;
  }

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

  .page-about .partner-item-wide {
    grid-column: 1 / -1;
  }

  .page-about .route-list {
    flex-direction: row;
    flex-wrap: wrap;
    gap: 24px;
  }

  .page-about .about-closing {
    padding: 36px 32px;
  }

  .page-about .closing-title {
    font-size: var(--f28);
  }
}

/* ---- 1024px：左侧固定章节目录 ---- */
@media (min-width: 1024px) {
  .page-about .about-shell {
    grid-template-columns: 208px minmax(0, 1fr);
    gap: 64px;
    padding: 56px 0 88px;
  }

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

  .page-about .about-index-list {
    display: block;
    padding: 0;
    overflow: visible;
  }

  .page-about .about-index-list li + li {
    margin-top: 2px;
  }

  .page-about .index-link {
    padding: 7px 0 7px 14px;
    border: 0;
    border-left: 2px solid transparent;
    background: none;
  }

  .page-about .index-link:hover {
    border-color: transparent;
    color: var(--cyan-soft);
  }

  .page-about .index-link[aria-current="true"] {
    border-left-color: var(--cyan);
    border-color: var(--cyan);
    color: var(--cyan);
    background: linear-gradient(90deg, rgba(63, 224, 200, 0.14), rgba(63, 224, 200, 0) 80%);
  }

  .page-about .tl-scroll {
    padding-right: 4px;
  }

  .page-about .tl-item {
    flex-basis: 268px;
    width: 268px;
    padding-right: 34px;
  }

  .page-about .tl-item:last-child::before {
    right: 34px;
  }

  .page-about .about-figure-right {
    max-width: 88%;
    margin-left: auto;
  }

  /* 桌面端恢复横向比例条 */
  .page-about .team-bar {
    flex-direction: row;
    height: 96px;
  }

  .page-about .team-seg {
    flex-direction: column;
    align-items: flex-start;
    justify-content: center;
    gap: 6px;
    width: auto;
    padding: 14px 16px;
    border-bottom: 0;
    border-right: 1px solid var(--line);
  }

  .page-about .team-seg:last-child {
    border-right: 0;
  }

  .page-about .seg-data { flex: 24 1 0; }
  .page-about .seg-video { flex: 15 1 0; }
  .page-about .seg-tech { flex: 14 1 0; }
  .page-about .seg-ops { flex: 9 1 0; }

  .page-about .team-seg-label {
    flex: none;
    font-size: var(--f12);
    color: var(--about-soft);
  }

  .page-about .team-seg-desc {
    top: calc(100% + 10px);
    width: 240px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .team-seg-desc,
  .page-about .index-link,
  .page-about .about-link,
  .page-about .flow-step,
  .page-about .principle {
    transition: none;
  }

  .page-about .team-seg-desc {
    transform: none;
  }
}