.page-about {
  --about-year-w: 88px;
  --about-rule: rgba(47, 243, 208, 0.2);
  --about-panel: rgba(12, 42, 32, 0.72);
}

/* 封面 */
.page-about .about-cover {
  position: relative;
  padding: clamp(26px, 6vw, 54px) 0 clamp(30px, 5vw, 44px);
  border-bottom: 1px solid var(--line);
  background:
    repeating-linear-gradient(180deg, rgba(47, 243, 208, 0.045) 0 1px, transparent 1px 6px),
    radial-gradient(130% 90% at 82% 0%, rgba(47, 243, 208, 0.13), transparent 62%),
    linear-gradient(180deg, #0c2a20 0%, #071a14 100%);
  overflow: hidden;
}

.page-about .about-crumbs {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  font-size: 12px;
  letter-spacing: 0.12em;
  color: var(--muted);
}

.page-about .about-crumbs a {
  color: var(--cyan-dim);
  text-decoration: none;
  border-bottom: 1px solid transparent;
}

.page-about .about-crumbs a:hover,
.page-about .about-crumbs a:focus-visible {
  color: var(--cyan);
  border-bottom-color: var(--cyan);
}

.page-about .about-cover .eyebrow {
  margin-top: 20px;
}

.page-about .about-cover h1 {
  margin: 12px 0 0;
  font-family: var(--font-display);
  font-size: clamp(2.1rem, 7.6vw, 4.4rem);
  line-height: 1.05;
  letter-spacing: -0.02em;
  font-weight: 800;
  color: var(--white);
  max-width: 15ch;
}

.page-about .about-cover__lede {
  margin: 20px 0 0;
  max-width: 58ch;
  font-size: clamp(15px, 3.4vw, 17px);
  line-height: 1.85;
  color: rgba(247, 251, 248, 0.82);
}

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

/* 年份刻度 */
.page-about .about-scale {
  margin-top: clamp(28px, 5vw, 42px);
  border-top: 1px solid var(--about-rule);
  overflow-x: auto;
  overscroll-behavior-x: contain;
  scrollbar-width: thin;
}

.page-about .about-scale ul {
  display: grid;
  grid-auto-flow: column;
  grid-auto-columns: minmax(78px, 1fr);
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .about-scale li {
  position: relative;
  padding: 16px 10px 4px 0;
}

.page-about .about-scale li::before {
  content: "";
  position: absolute;
  top: -1px;
  left: 0;
  width: 1px;
  height: 10px;
  background: var(--cyan);
  opacity: 0.55;
}

.page-about .about-scale a {
  display: flex;
  flex-direction: column;
  gap: 5px;
  text-decoration: none;
  color: var(--white);
  transition: color 0.2s var(--ease);
}

.page-about .about-scale a .mono {
  font-family: var(--font-mono);
  font-size: clamp(15px, 3.6vw, 19px);
  font-variant-numeric: tabular-nums;
  letter-spacing: 0.02em;
}

.page-about .about-scale a small {
  font-size: 12px;
  letter-spacing: 0.12em;
  color: var(--muted);
}

.page-about .about-scale a:hover .mono,
.page-about .about-scale a:focus-visible .mono {
  color: var(--cyan);
}

.page-about .about-scale a:hover small,
.page-about .about-scale a:focus-visible small {
  color: var(--orange-soft);
}

/* 章节标题 */
.page-about .about-head {
  margin-bottom: clamp(20px, 4vw, 34px);
}

.page-about .about-head h2 {
  margin: 8px 0 0;
  font-family: var(--font-display);
  font-size: clamp(1.45rem, 4.8vw, 2.1rem);
  line-height: 1.2;
  letter-spacing: -0.01em;
  font-weight: 800;
  color: var(--white);
  max-width: 24ch;
}

/* 起点 */
.page-about .about-origin__grid {
  display: grid;
  gap: clamp(24px, 4vw, 40px);
}

.page-about .about-origin__text p {
  margin: 0 0 16px;
  font-size: 16px;
  line-height: 1.85;
  color: rgba(247, 251, 248, 0.8);
}

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

.page-about .about-figures {
  display: grid;
  gap: 1px;
  margin: 0;
  padding: 0;
  list-style: none;
  border: 1px solid var(--line-soft);
  background: var(--line-soft);
}

.page-about .about-figures li {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  align-items: baseline;
  gap: 14px;
  padding: 16px 18px;
  background: var(--about-panel);
}

.page-about .about-figures strong {
  font-family: var(--font-mono);
  font-size: clamp(22px, 5.2vw, 30px);
  line-height: 1;
  color: var(--cyan);
  font-variant-numeric: tabular-nums;
}

.page-about .about-figures span {
  font-size: 13px;
  line-height: 1.65;
  color: var(--muted);
}

/* 版本演进 */
.page-about .about-track {
  display: grid;
  gap: clamp(18px, 3.4vw, 30px);
}

.page-about .about-era {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 12px;
}

.page-about .about-era__year {
  display: inline-flex;
  align-items: center;
  width: fit-content;
  padding: 5px 12px;
  border: 1px solid var(--line);
  background: rgba(47, 243, 208, 0.08);
  color: var(--cyan);
}

.page-about .about-era__year .mono {
  font-family: var(--font-mono);
  font-size: 14px;
  letter-spacing: 0.06em;
  font-variant-numeric: tabular-nums;
}

.page-about .about-era__body {
  min-width: 0;
}

.page-about .about-node {
  padding: clamp(16px, 3vw, 24px);
  border: 1px solid var(--line-soft);
  background: linear-gradient(180deg, rgba(12, 42, 32, 0.96), rgba(7, 26, 20, 0.96));
  transition: border-color 0.24s var(--ease), transform 0.24s var(--ease);
}

.page-about .about-node:hover {
  border-color: var(--cyan);
  transform: translateY(-3px);
}

.page-about .about-node__tag {
  margin: 0 0 10px;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.page-about .about-node h3 {
  margin: 0 0 10px;
  font-size: clamp(16px, 3.8vw, 19px);
  line-height: 1.4;
  font-weight: 700;
  color: var(--white);
}

.page-about .about-node p {
  margin: 0;
  font-size: 14px;
  line-height: 1.85;
  color: rgba(247, 251, 248, 0.78);
}

.page-about .about-media {
  margin: clamp(22px, 4vw, 34px) 0 0;
}

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

.page-about .about-media--archive {
  margin: 0;
}

/* 历史资料 */
.page-about .about-archive__panel {
  padding: clamp(20px, 4vw, 44px);
  border: 1px solid var(--paper-edge);
  color: var(--brown);
  background-image: repeating-linear-gradient(90deg, transparent 0 31px, rgba(27, 23, 18, 0.05) 31px 32px);
}

.page-about .about-archive__eyebrow {
  color: #b8410f;
}

.page-about .about-archive__panel h2 {
  margin: 8px 0 clamp(16px, 3vw, 26px);
  font-family: var(--font-display);
  font-size: clamp(1.4rem, 4.6vw, 2rem);
  line-height: 1.22;
  font-weight: 800;
  color: var(--brown);
  max-width: 22ch;
}

.page-about .about-archive__grid {
  display: grid;
  gap: clamp(20px, 3.4vw, 32px);
}

.page-about .about-archive__text p {
  margin: 0 0 14px;
  font-size: 15px;
  line-height: 1.9;
  color: rgba(27, 23, 18, 0.82);
}

.page-about .about-file {
  border: 1px solid var(--paper-edge);
  background: rgba(255, 255, 255, 0.52);
  margin-top: 12px;
}

.page-about .about-file summary {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px;
  padding: 13px 16px;
  cursor: pointer;
  font-size: 14px;
  font-weight: 700;
  color: var(--brown);
  list-style: none;
}

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

.page-about .about-file summary::after {
  content: "+";
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: 18px;
  line-height: 1;
  color: #b8410f;
}

.page-about .about-file[open] summary::after {
  content: "–";
}

.page-about .about-file summary:focus-visible {
  outline: 2px solid #b8410f;
  outline-offset: -2px;
}

.page-about .about-file__body {
  padding: 12px 16px 16px;
  border-top: 1px dashed var(--paper-edge);
}

.page-about .about-file__body p {
  margin: 0;
  font-size: 14px;
  line-height: 1.85;
  color: rgba(27, 23, 18, 0.8);
}

/* 团队 */
.page-about .about-meter {
  display: flex;
  height: 10px;
  margin-bottom: clamp(16px, 3vw, 24px);
  border: 1px solid var(--line-soft);
  background: rgba(7, 26, 20, 0.8);
}

.page-about .about-meter__seg {
  height: 100%;
}

.page-about .about-meter__seg--ops { flex: 18; background: var(--cyan); }
.page-about .about-meter__seg--edit { flex: 12; background: var(--cyan-dim); }
.page-about .about-meter__seg--tech { flex: 8; background: var(--orange); }
.page-about .about-meter__seg--care { flex: 4; background: var(--orange-soft); }

.page-about .about-roster {
  display: grid;
  gap: 1px;
  margin: 0;
  padding: 0;
  list-style: none;
  border: 1px solid var(--line-soft);
  background: var(--line-soft);
}

.page-about .about-roster__item {
  display: grid;
  gap: 6px;
  padding: 18px;
  background: var(--about-panel);
  transition: background 0.24s var(--ease);
}

.page-about .about-roster__item:hover {
  background: rgba(20, 184, 166, 0.14);
}

.page-about .about-roster__num {
  font-family: var(--font-mono);
  font-size: clamp(24px, 5.4vw, 34px);
  line-height: 1;
  color: var(--cyan);
  font-variant-numeric: tabular-nums;
}

.page-about .about-roster__name {
  font-size: 15px;
  font-weight: 700;
  color: var(--white);
}

.page-about .about-roster__desc {
  font-size: 13px;
  line-height: 1.75;
  color: var(--muted);
  transition: color 0.24s var(--ease);
}

.page-about .about-roster__item:hover .about-roster__desc {
  color: rgba(247, 251, 248, 0.92);
}

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

.page-about .about-step {
  padding: 20px 18px;
  background: var(--about-panel);
}

.page-about .about-step__idx {
  display: block;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.18em;
  color: var(--orange);
}

.page-about .about-step h3 {
  margin: 10px 0 8px;
  font-size: 16px;
  font-weight: 700;
  color: var(--white);
}

.page-about .about-step p {
  margin: 0;
  font-size: 14px;
  line-height: 1.8;
  color: rgba(247, 251, 248, 0.78);
}

.page-about .about-promise {
  display: grid;
  gap: 10px;
  margin: clamp(20px, 3.4vw, 28px) 0 0;
  padding: 0;
  list-style: none;
}

.page-about .about-promise li {
  position: relative;
  padding-left: 20px;
  font-size: 14px;
  line-height: 1.8;
  color: rgba(247, 251, 248, 0.82);
}

.page-about .about-promise li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.62em;
  width: 8px;
  height: 8px;
  background: var(--cyan);
}

/* 合作生态 */
.page-about .about-partners__lede {
  margin: 0 0 clamp(18px, 3vw, 26px);
  max-width: 62ch;
  font-size: 15px;
  line-height: 1.85;
  color: rgba(247, 251, 248, 0.8);
}

.page-about .about-partners__grid {
  display: grid;
  gap: 1px;
  margin: 0;
  padding: 0;
  list-style: none;
  border: 1px solid var(--line-soft);
  background: var(--line-soft);
}

.page-about .about-partner {
  display: grid;
  gap: 8px;
  padding: 20px 16px;
  background: var(--about-panel);
}

.page-about .about-partner strong {
  font-family: var(--font-mono);
  font-size: clamp(24px, 6vw, 32px);
  line-height: 1;
  color: var(--cyan);
  font-variant-numeric: tabular-nums;
}

.page-about .about-partner strong small {
  font-size: 0.45em;
  margin-left: 2px;
  color: var(--cyan-dim);
}

.page-about .about-partner span {
  font-size: 13px;
  line-height: 1.7;
  color: var(--muted);
}

/* 下一步 */
.page-about .about-next__panel {
  display: grid;
  gap: clamp(20px, 3.4vw, 28px);
  padding: clamp(20px, 4vw, 40px);
  border: 1px solid rgba(255, 106, 42, 0.5);
  background: linear-gradient(120deg, rgba(255, 106, 42, 0.16), rgba(47, 243, 208, 0.07) 72%);
}

.page-about .about-next__panel h2 {
  margin: 8px 0 12px;
  font-family: var(--font-display);
  font-size: clamp(1.35rem, 4.4vw, 1.9rem);
  line-height: 1.25;
  font-weight: 800;
  color: var(--white);
  max-width: 20ch;
}

.page-about .about-next__text {
  margin: 0;
  max-width: 52ch;
  font-size: 14px;
  line-height: 1.85;
  color: rgba(247, 251, 248, 0.82);
}

.page-about .about-next__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  align-content: start;
}

/* 平板起 */
@media (min-width: 640px) {
  .page-about .about-partners__grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

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

@media (min-width: 860px) {
  .page-about .about-origin__grid {
    grid-template-columns: 1.25fr 0.85fr;
    align-items: start;
  }

  .page-about .about-era {
    grid-template-columns: var(--about-year-w) minmax(0, 1fr);
    gap: clamp(20px, 3vw, 40px);
    align-items: start;
  }

  .page-about .about-era__year {
    position: sticky;
    top: 88px;
    justify-content: flex-start;
    width: auto;
    padding: 2px 0 2px 14px;
    border: 0;
    border-left: 2px solid var(--cyan);
    background: transparent;
  }

  .page-about .about-era__year .mono {
    font-size: clamp(20px, 2.4vw, 27px);
    font-weight: 700;
  }

  .page-about .about-era__body {
    border-left: 1px solid var(--line);
    padding-left: clamp(14px, 2.4vw, 26px);
  }

  .page-about .about-era:nth-child(even) .about-era__body {
    padding-left: clamp(22px, 4vw, 46px);
  }

  .page-about .about-archive__grid {
    grid-template-columns: 1.15fr 0.85fr;
    align-items: start;
  }

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

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

  .page-about .about-next__panel {
    grid-template-columns: 1.3fr 0.7fr;
    align-items: center;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-node,
  .page-about .about-roster__item,
  .page-about .about-roster__desc,
  .page-about .about-scale a {
    transition: none;
  }

  .page-about .about-node:hover {
    transform: none;
  }
}