.page-about {
  --about-track-w: 212px;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  padding-top: 8px;
  padding-bottom: 44px;
  border-bottom: 1px solid var(--line-soft);
}

.page-about .about-hero-grid {
  display: grid;
  gap: 30px;
  margin-top: 18px;
}

.page-about .about-hero-lead .lede {
  margin: 18px 0 0;
  max-width: 48ch;
  color: var(--muted);
}

.page-about .about-hero-year {
  font-family: var(--font-mono);
  color: var(--lime);
  letter-spacing: -.03em;
}

.page-about .about-hero-actions {
  margin-top: 26px;
  gap: 12px;
  flex-wrap: wrap;
}

.page-about .about-hero-board {
  padding: 18px 18px 12px;
  border: 1px solid var(--line);
  background:
    linear-gradient(155deg, rgba(25, 230, 208, .08), transparent 62%),
    var(--panel);
}

.page-about .about-board-title {
  margin: 0 0 6px;
  font-size: 11px;
  letter-spacing: .24em;
  color: var(--cyan);
  text-transform: uppercase;
}

.page-about .about-board-list {
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .about-board-list li {
  display: flex;
  align-items: baseline;
  gap: 14px;
  padding: 11px 0;
  border-bottom: 1px dashed var(--line-soft);
}

.page-about .about-board-list li:last-child {
  border-bottom: 0;
}

.page-about .about-board-list .data-num {
  font-family: var(--font-mono);
  font-size: 26px;
  line-height: 1;
  letter-spacing: -.03em;
  color: var(--cyan);
  min-width: 78px;
}

.page-about .about-board-list li:first-child .data-num {
  color: var(--lime);
}

.page-about .about-unit {
  font-size: .55em;
  margin-left: 2px;
}

.page-about .about-board-key {
  font-size: 13px;
  color: var(--muted);
}

/* ---------- 侧轨 + 正文 ---------- */
.page-about .about-shell {
  margin-top: 34px;
  margin-bottom: 56px;
}

.page-about .about-track {
  margin-bottom: 30px;
  padding: 8px 0;
  border-top: 1px solid var(--line-soft);
  border-bottom: 1px solid var(--line-soft);
}

.page-about .about-track-title {
  display: none;
}

.page-about .about-track-list {
  list-style: none;
  margin: 0;
  padding: 0 0 4px;
  display: flex;
  gap: 6px;
  overflow-x: auto;
  scroll-snap-type: x proximity;
  -webkit-overflow-scrolling: touch;
}

.page-about .about-track-list li {
  flex: 0 0 auto;
  scroll-snap-align: start;
}

.page-about .about-track a {
  display: inline-flex;
  align-items: baseline;
  gap: 7px;
  padding: 7px 12px;
  font-size: 13px;
  white-space: nowrap;
  color: var(--muted);
  text-decoration: none;
  border: 1px solid transparent;
  transition: color .2s var(--ease), border-color .2s var(--ease), background-color .2s var(--ease);
}

.page-about .about-track a:hover,
.page-about .about-track a:focus-visible {
  color: var(--text);
  border-color: var(--line);
  background: var(--deep);
}

.page-about .about-track-num {
  font-size: 11px;
  color: var(--cyan);
}

.page-about .about-sec {
  margin-bottom: 56px;
  scroll-margin-top: 96px;
}

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

.page-about .about-sec-lede {
  margin: 12px 0 0;
  max-width: 58ch;
  font-size: 15.5px;
  line-height: 1.78;
  color: var(--muted);
}

.page-about .about-copy {
  margin-top: 14px;
  max-width: 62ch;
}

.page-about .about-copy p {
  margin: 0 0 14px;
  line-height: 1.85;
}

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

.page-about .about-body a:not(.btn) {
  color: var(--cyan);
  text-decoration: underline;
  text-decoration-thickness: 1px;
  text-underline-offset: 3px;
}

.page-about .about-body a:not(.btn):hover {
  color: var(--lime);
}

/* ---------- 引文 ---------- */
.page-about .about-quote {
  margin: 28px 0 0;
  padding: 22px 22px 20px;
  background: var(--deep);
  border-left: 3px solid var(--cyan);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 18px), calc(100% - 18px) 100%, 0 100%);
}

.page-about .about-quote p:first-child {
  margin: 0;
  font-family: var(--font-serif);
  font-size: clamp(17px, 4.2vw, 24px);
  line-height: 1.65;
  color: var(--text);
}

.page-about .about-quote-src {
  margin: 14px 0 0;
  font-size: 11.5px;
  letter-spacing: .12em;
  color: var(--muted);
}

/* ---------- 时间轴 ---------- */
.page-about .about-band {
  margin: 24px 0 26px;
  background: var(--deep);
  clip-path: polygon(0 0, 100% 5%, 100% 100%, 0 95%);
}

.page-about .about-band img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 8 / 3;
  object-fit: cover;
  opacity: .45;
}

.page-about .about-stops {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 12px;
}

.page-about .about-stop {
  position: relative;
  display: grid;
  gap: 6px;
  padding: 16px 18px;
  background: var(--deep);
  border: 1px solid var(--line-soft);
  border-left: 3px solid var(--line);
  transition: border-color .25s var(--ease), background-color .25s var(--ease);
}

.page-about .about-stop::before {
  content: "";
  position: absolute;
  left: -6px;
  top: 24px;
  width: 9px;
  height: 9px;
  background: var(--line);
  transform: rotate(45deg);
  transition: background-color .25s var(--ease);
}

.page-about .about-stop:hover,
.page-about .about-stop:focus-within {
  border-left-color: var(--cyan);
  background: var(--panel);
}

.page-about .about-stop:hover::before,
.page-about .about-stop:focus-within::before {
  background: var(--lime);
}

.page-about .about-stop-year {
  font-family: var(--font-mono);
  font-size: 30px;
  line-height: 1;
  letter-spacing: -.03em;
  color: var(--muted);
  transition: color .25s var(--ease);
}

.page-about .about-stop:hover .about-stop-year,
.page-about .about-stop:focus-within .about-stop-year {
  color: var(--lime);
}

.page-about .about-stop-body h3 {
  margin: 0 0 6px;
  font-size: 17px;
  line-height: 1.4;
}

.page-about .about-stop-body p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.75;
  color: var(--muted);
}

/* ---------- 工序 ---------- */
.page-about .about-figure {
  margin: 26px 0 0;
}

.page-about .about-figure img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 3 / 2;
  object-fit: cover;
  border: 1px solid var(--line-soft);
}

.page-about .about-figure figcaption {
  margin-top: 10px;
  font-size: 12.5px;
  line-height: 1.65;
  color: var(--muted);
}

.page-about .about-steps {
  list-style: none;
  margin: 24px 0 0;
  padding: 0;
  display: grid;
  gap: 14px;
}

.page-about .about-step {
  padding: 22px 18px 18px;
  background: var(--panel);
  border: 1px solid var(--line-soft);
  transition: border-color .25s var(--ease), background-color .25s var(--ease);
}

.page-about .about-step:hover {
  border-color: var(--cyan);
  background: var(--panel-2);
}

.page-about .about-step-num {
  display: block;
  margin-bottom: 10px;
  font-size: 11px;
  letter-spacing: .22em;
  color: var(--cyan);
}

.page-about .about-step h3 {
  margin: 0 0 8px;
  font-size: 17px;
}

.page-about .about-step p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.75;
  color: var(--muted);
}

/* ---------- 合作 ---------- */
.page-about .about-cards {
  list-style: none;
  margin: 24px 0 0;
  padding: 0;
  display: grid;
  gap: 14px;
}

.page-about .about-card {
  padding: 20px 18px;
  background: var(--deep);
  border: 1px solid var(--line-soft);
  transition: border-color .25s var(--ease), background-color .25s var(--ease);
}

.page-about .about-card:hover,
.page-about .about-card:focus-within {
  border-color: var(--cyan);
  background: var(--panel);
}

.page-about .about-card-k {
  margin: 0 0 10px;
  font-family: var(--font-mono);
  font-size: 22px;
  line-height: 1;
  letter-spacing: -.02em;
  color: var(--lime);
}

.page-about .about-card h3 {
  margin: 0 0 8px;
  font-size: 16.5px;
}

.page-about .about-card p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.75;
  color: var(--muted);
}

.page-about .about-coop {
  margin-top: 22px;
  padding: 20px 18px;
  background: var(--deep);
  border-left: 3px solid var(--orange);
}

.page-about .about-coop h3 {
  margin: 0 0 12px;
  font-size: 16px;
}

.page-about .about-coop ul {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 10px;
}

.page-about .about-coop li {
  position: relative;
  padding-left: 18px;
  font-size: 14.5px;
  line-height: 1.75;
  color: var(--muted);
}

.page-about .about-coop li::before {
  content: "";
  position: absolute;
  left: 0;
  top: .7em;
  width: 8px;
  height: 2px;
  background: var(--cyan);
}

/* ---------- 成都 ---------- */
.page-about .about-place {
  display: grid;
  gap: 22px;
}

.page-about .about-place-media img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 4 / 3;
  object-fit: cover;
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 26px), calc(100% - 26px) 100%, 0 100%);
}

.page-about .about-place-text p {
  margin: 12px 0 0;
  max-width: 56ch;
  line-height: 1.85;
  color: var(--muted);
}

.page-about .about-place-actions {
  margin-top: 24px;
  gap: 12px;
  flex-wrap: wrap;
}

/* ---------- 断点 ---------- */
@media (min-width: 720px) {
  .page-about .about-stop {
    grid-template-columns: 132px minmax(0, 1fr);
    align-items: start;
    gap: 22px;
    padding: 18px 20px;
  }

  .page-about .about-stop-year {
    font-size: 40px;
  }

  .page-about .about-stops {
    gap: 14px;
  }

  .page-about .about-steps {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 16px;
  }

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

@media (min-width: 900px) {
  .page-about .about-hero-grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 4fr);
    gap: 56px;
    align-items: end;
  }

  .page-about .about-shell {
    display: grid;
    grid-template-columns: var(--about-track-w) minmax(0, 1fr);
    column-gap: 56px;
    align-items: start;
  }

  .page-about .about-track {
    position: sticky;
    top: 108px;
    margin-bottom: 0;
    padding: 2px 0 0 16px;
    border-top: 0;
    border-bottom: 0;
    border-left: 1px solid var(--line);
  }

  .page-about .about-track-title {
    display: block;
    margin: 0 0 14px;
    font-size: 10.5px;
    letter-spacing: .24em;
    color: var(--muted);
  }

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

  .page-about .about-track-list li {
    margin-bottom: 2px;
  }

  .page-about .about-track a {
    display: flex;
    width: 100%;
    padding: 9px 10px;
    white-space: normal;
    border: 0;
    border-left: 2px solid transparent;
    margin-left: -17px;
    line-height: 1.5;
  }

  .page-about .about-track a:hover,
  .page-about .about-track a:focus-visible {
    color: var(--text);
    background: linear-gradient(90deg, rgba(25, 230, 208, .13), transparent 78%);
    border-left-color: var(--cyan);
  }

  .page-about .about-stop:nth-child(2) {
    margin-left: 20px;
  }

  .page-about .about-stop:nth-child(3) {
    margin-left: 40px;
  }

  .page-about .about-stop:nth-child(4) {
    margin-left: 60px;
  }

  .page-about .about-stop:nth-child(5) {
    margin-left: 80px;
  }

  .page-about .about-place {
    grid-template-columns: minmax(0, 5fr) minmax(0, 6fr);
    gap: 44px;
    align-items: center;
  }

  .page-about .about-sec {
    margin-bottom: 64px;
  }

  .page-about .about-shell {
    margin-bottom: 80px;
  }
}