.page-about {
  --about-line: rgba(200, 164, 106, 0.55);
}

/* 首屏 */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  background: var(--ink);
  color: var(--silver);
  padding: 26px 0 54px;
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  top: -40%;
  right: -25%;
  width: 85%;
  height: 180%;
  transform: rotate(-8deg);
  background: linear-gradient(150deg, rgba(200, 164, 106, 0.18), rgba(53, 224, 208, 0.08) 58%, transparent 76%);
  pointer-events: none;
}

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

.page-about .about-hero .breadcrumb {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: rgba(232, 234, 237, 0.6);
  margin-bottom: 26px;
}

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

.page-about .about-hero .breadcrumb a:hover {
  text-decoration: underline;
  text-underline-offset: 4px;
}

.page-about .about-crumb-sep {
  color: var(--rule);
}

.page-about .eyebrow {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.12em;
  color: var(--gold);
  margin: 0 0 12px;
}

.page-about h1 {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(28px, 7vw, 52px);
  line-height: 1.2;
  letter-spacing: -0.02em;
  margin: 0 0 18px;
  max-width: 16em;
}

.page-about .about-hero-lead {
  font-size: 16px;
  line-height: 1.9;
  color: rgba(232, 234, 237, 0.78);
  max-width: 30em;
  margin: 0;
}

.page-about .about-hero-facts {
  display: flex;
  flex-wrap: wrap;
  gap: 20px 32px;
  margin: 28px 0 30px;
  padding: 0;
  list-style: none;
}

.page-about .about-fact {
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding-left: 12px;
  border-left: 1px solid var(--gold);
}

.page-about .about-fact-num {
  font-family: var(--font-mono);
  font-size: 21px;
  letter-spacing: 0.02em;
  color: var(--gold-soft);
}

.page-about .about-fact-label {
  font-size: 12px;
  letter-spacing: 0.08em;
  color: rgba(232, 234, 237, 0.62);
}

.page-about .about-hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

/* 时间线 */
.page-about .about-timeline {
  background: var(--paper);
  color: var(--ink);
  padding: 50px 0 58px;
}

.page-about .about-timeline h2,
.page-about .about-batch h2,
.page-about .about-reach h2,
.page-about .about-help h2,
.page-about .about-next h2,
.page-about .about-end-card h2 {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(23px, 4.4vw, 32px);
  line-height: 1.32;
  letter-spacing: -0.01em;
  margin: 0 0 12px;
}

.page-about .about-lead {
  font-size: 15px;
  line-height: 1.95;
  color: var(--muted);
  max-width: 34em;
  margin: 0 0 28px;
}

.page-about .tl-dir-list {
  display: flex;
  gap: 8px;
  overflow-x: auto;
  margin: 0 0 24px;
  padding: 0 0 6px;
  list-style: none;
  scrollbar-width: thin;
}

.page-about .tl-dir-list li {
  flex: 0 0 auto;
}

.page-about .tl-dir-list a {
  display: flex;
  align-items: baseline;
  gap: 6px;
  padding: 7px 12px;
  border: 1px solid var(--hairline);
  border-radius: var(--r-pill);
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--muted);
  text-decoration: none;
  white-space: nowrap;
  transition: color var(--t-fast) var(--ease), border-color var(--t-fast) var(--ease);
}

.page-about .tl-dir-list a:hover {
  color: var(--ink);
  border-color: var(--gold);
}

.page-about .tl-dir-list a[aria-current] {
  color: var(--cyan-deep);
  border-color: var(--cyan-deep);
}

.page-about .tl-dir-year {
  font-weight: 500;
}

.page-about .tl-wrap {
  position: relative;
}

.page-about .tl-thread {
  display: none;
}

.page-about .tl {
  position: relative;
  z-index: 1;
  display: flex;
  flex-direction: column;
  gap: 22px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .tl-item {
  display: grid;
  grid-template-columns: 36px minmax(0, 1fr);
  gap: 12px;
  align-items: start;
}

.page-about .tl-year {
  writing-mode: vertical-rl;
  text-orientation: mixed;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--muted);
  padding-top: 6px;
}

.page-about .tl-body {
  position: relative;
  min-width: 0;
}

.page-about .tl-body::before {
  content: "";
  position: absolute;
  left: -7px;
  top: 24px;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--gold);
  box-shadow: 0 0 0 4px var(--paper);
}

.page-about .tl-card {
  background: #ffffff;
  border: 1px solid var(--hairline);
  border-radius: var(--r-lg);
  padding: 20px 18px 18px;
  transition: border-color var(--t-fast) var(--ease), border-radius var(--t-mid) var(--ease);
}

.page-about .tl-card:hover {
  border-color: var(--gold);
  border-radius: var(--r-md);
}

.page-about .tl-tag {
  display: inline-flex;
  align-items: center;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  color: var(--ink);
  background: var(--gold-soft);
  border-radius: var(--r-pill);
  padding: 4px 11px;
  margin-bottom: 12px;
  text-decoration: none;
}

.page-about .tl-tag--link {
  transition: background var(--t-fast) var(--ease);
}

.page-about .tl-tag--link:hover {
  background: var(--gold);
}

.page-about .tl-card h3 {
  font-family: var(--font-display);
  font-size: 19px;
  line-height: 1.45;
  letter-spacing: -0.01em;
  margin: 0 0 10px;
}

.page-about .tl-card p {
  font-size: 14px;
  line-height: 1.9;
  color: var(--muted);
  margin: 0;
}

.page-about .tl-facts {
  display: flex;
  flex-wrap: wrap;
  gap: 14px 26px;
  margin: 16px 0 0;
  padding: 14px 0 0;
  border-top: 1px solid var(--hairline);
}

.page-about .tl-fact {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.page-about .tl-fact-num {
  font-family: var(--font-mono);
  font-size: 17px;
  color: var(--ink);
}

.page-about .tl-fact-label {
  font-size: 11px;
  letter-spacing: 0.06em;
  color: var(--muted);
}

.page-about .tl-more {
  margin-top: 14px;
}

.page-about .tl-more summary {
  list-style: none;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 7px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.04em;
  color: var(--cyan-deep);
  transition: color var(--t-fast) var(--ease);
}

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

.page-about .tl-more summary::before {
  content: "+";
  font-size: 14px;
  line-height: 1;
}

.page-about .tl-more[open] summary::before {
  content: "−";
}

.page-about .tl-more summary:hover,
.page-about .tl-more summary:focus-visible {
  color: var(--ink);
}

.page-about .tl-more summary:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 3px;
}

.page-about .tl-more p {
  margin: 10px 0 0;
  font-size: 14px;
  line-height: 1.85;
  color: var(--muted);
}

.page-about .about-figure {
  margin: 34px 0 0;
}

.page-about .about-figure img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  border-radius: var(--r-lg);
  object-fit: cover;
}

.page-about .about-figure figcaption,
.page-about .reach-figure figcaption {
  margin-top: 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.04em;
  color: var(--muted);
}

/* 批次制度 */
.page-about .about-batch {
  background: var(--ink);
  color: var(--silver);
  padding: 50px 0 54px;
}

.page-about .about-batch-lead {
  font-size: 15px;
  line-height: 1.95;
  color: rgba(232, 234, 237, 0.74);
  max-width: 32em;
  margin: 0 0 28px;
}

.page-about .batch-list {
  display: grid;
  gap: 14px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .batch-item {
  background: var(--graphite);
  border: 1px solid var(--rule);
  border-radius: var(--r-lg);
  padding: 22px 20px;
  transition: border-color var(--t-fast) var(--ease);
}

.page-about .batch-item:hover {
  border-color: var(--gold);
}

.page-about .batch-num {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--gold);
}

.page-about .batch-item h3 {
  font-family: var(--font-sans);
  font-weight: 500;
  font-size: 17px;
  line-height: 1.5;
  margin: 8px 0 8px;
  color: var(--silver);
}

.page-about .batch-item p {
  margin: 0;
  font-size: 14px;
  line-height: 1.85;
  color: rgba(232, 234, 237, 0.72);
}

.page-about .about-batch-cta {
  margin: 28px 0 0;
}

/* 用户与覆盖 */
.page-about .about-reach {
  background: var(--paper);
  color: var(--ink);
  padding: 50px 0 54px;
}

.page-about .reach-grid {
  display: grid;
  gap: 28px;
  align-items: start;
}

.page-about .reach-stats {
  display: grid;
  grid-template-columns: 1fr;
  gap: 14px;
  margin: 0 0 22px;
  padding: 0;
  list-style: none;
}

.page-about .reach-stat {
  border-top: 2px solid var(--gold);
  padding: 12px 0 0;
}

.page-about .reach-num {
  display: block;
  font-family: var(--font-mono);
  font-size: 21px;
  color: var(--ink);
}

.page-about .reach-label {
  display: block;
  margin-top: 4px;
  font-size: 12px;
  letter-spacing: 0.04em;
  color: var(--muted);
}

.page-about .reach-note {
  font-size: 14px;
  line-height: 1.9;
  color: var(--muted);
  margin: 0;
  padding-left: 14px;
  border-left: 1px solid var(--about-line);
}

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

.page-about .reach-figure img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  border-radius: var(--r-lg);
  object-fit: cover;
}

/* 帮助中心 */
.page-about .about-help {
  background: var(--paper);
  color: var(--ink);
  padding: 8px 0 54px;
  border-top: 1px solid var(--hairline);
  padding-top: 44px;
}

.page-about .help-topics {
  display: grid;
  grid-template-columns: 1fr;
  gap: 12px;
  margin: 0 0 24px;
  padding: 0;
  list-style: none;
}

.page-about .help-topic {
  background: #ffffff;
  border: 1px solid var(--hairline);
  border-radius: var(--r-md);
  padding: 18px 16px;
  transition: border-color var(--t-fast) var(--ease), border-radius var(--t-mid) var(--ease);
}

.page-about .help-topic:hover {
  border-color: var(--gold);
  border-radius: var(--r-sm);
}

.page-about .help-topic-num {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--gold);
}

.page-about .help-topic h3 {
  font-family: var(--font-sans);
  font-weight: 500;
  font-size: 16px;
  line-height: 1.5;
  margin: 6px 0 6px;
}

.page-about .help-topic p {
  margin: 0;
  font-size: 14px;
  line-height: 1.85;
  color: var(--muted);
}

.page-about .help-foot {
  font-size: 14px;
  line-height: 1.9;
  color: var(--muted);
  max-width: 36em;
  margin: 0 0 22px;
}

.page-about .help-cta {
  margin: 0;
}

/* 未来方向 */
.page-about .about-next {
  background: var(--ink);
  color: var(--silver);
  padding: 50px 0 54px;
}

.page-about .next-list {
  display: grid;
  gap: 14px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .next-item {
  background: var(--graphite);
  border: 1px solid var(--rule);
  border-radius: var(--r-lg);
  padding: 20px 18px;
  transition: border-color var(--t-fast) var(--ease), transform var(--t-mid) var(--ease);
}

.page-about .next-item:hover {
  border-color: var(--gold);
}

.page-about .next-num {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--cyan);
}

.page-about .next-item h3 {
  font-family: var(--font-sans);
  font-weight: 500;
  font-size: 17px;
  line-height: 1.5;
  margin: 8px 0 8px;
  color: var(--silver);
}

.page-about .next-item p {
  margin: 0;
  font-size: 14px;
  line-height: 1.85;
  color: rgba(232, 234, 237, 0.72);
}

/* 结尾 */
.page-about .about-end {
  background: var(--ink);
  color: var(--silver);
  padding: 0 0 56px;
  border-top: 1px solid var(--hairline-light);
}

.page-about .about-end-media {
  margin: 0 0 26px;
}

.page-about .about-end-media img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  border-radius: var(--r-lg);
  object-fit: cover;
  opacity: 0.55;
}

.page-about .about-end-card {
  background: var(--graphite);
  border: 1px solid var(--rule);
  border-radius: var(--r-xl);
  padding: 26px 20px;
}

.page-about .about-end-card p {
  font-size: 15px;
  line-height: 1.9;
  color: rgba(232, 234, 237, 0.76);
  max-width: 32em;
  margin: 0 0 22px;
}

.page-about .about-end-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

/* 中等屏幕 */
@media (min-width: 560px) {
  .page-about .reach-stats {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

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

@media (min-width: 820px) {
  .page-about .batch-list {
    grid-template-columns: 1.15fr 1fr 1fr;
    gap: 18px;
  }

  .page-about .next-list {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 18px;
  }

  .page-about .about-end-card {
    padding: 32px 30px;
  }
}

/* 桌面：侧轨目录 + 右错位时间线 */
@media (min-width: 900px) {
  .page-about .about-hero {
    padding: 34px 0 68px;
  }

  .page-about .about-timeline {
    padding: 64px 0 72px;
  }

  .page-about .tl-layout {
    display: grid;
    grid-template-columns: 104px minmax(0, 1fr);
    gap: 44px;
    align-items: start;
  }

  .page-about .tl-dir {
    position: sticky;
    top: 96px;
  }

  .page-about .tl-dir-list {
    flex-direction: column;
    overflow: visible;
    gap: 16px;
    margin: 0;
    padding: 0;
  }

  .page-about .tl-dir-list a {
    flex-direction: column;
    align-items: flex-start;
    gap: 3px;
    padding: 0 0 0 12px;
    border: 0;
    border-left: 1px solid var(--hairline);
    border-radius: 0;
    font-size: 13px;
  }

  .page-about .tl-dir-list a[aria-current] {
    border-left-color: var(--cyan);
  }

  .page-about .tl-thread {
    display: block;
    position: absolute;
    inset: 0;
    width: 100%;
    height: 100%;
    z-index: 0;
    opacity: 0.85;
    pointer-events: none;
  }

  .page-about .tl-item {
    grid-template-columns: 52px minmax(0, 1fr);
    gap: 20px;
    margin-bottom: 16px;
  }

  .page-about .tl-item:nth-child(1) {
    margin-right: 22%;
  }

  .page-about .tl-item:nth-child(2) {
    margin-left: 6%;
    margin-right: 14%;
  }

  .page-about .tl-item:nth-child(3) {
    margin-left: 12%;
    margin-right: 7%;
  }

  .page-about .tl-item:nth-child(4) {
    margin-left: 18%;
  }

  .page-about .tl-card {
    padding: 26px 26px 22px;
  }

  .page-about .tl-body::before {
    top: 30px;
  }

  .page-about .reach-grid {
    grid-template-columns: minmax(0, 1.3fr) minmax(0, 0.7fr);
    gap: 44px;
  }

  .page-about .about-batch,
  .page-about .about-reach,
  .page-about .about-next {
    padding: 64px 0 68px;
  }

  .page-about .about-help {
    padding: 56px 0 68px;
  }
}

@media (min-width: 1180px) {
  .page-about .help-topics {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .tl-card,
  .page-about .help-topic,
  .page-about .next-item,
  .page-about .batch-item,
  .page-about .tl-tag--link,
  .page-about .tl-dir-list a {
    transition: none;
  }
}
<<<END>>>