.page-about {
  --about-aside-w: 132px;
  --about-gap: 28px;
}

.page-about .crumbs {
  padding-top: 28px;
  font-size: 13px;
  letter-spacing: 0.02em;
}

.page-about .crumbs__sep {
  margin: 0 8px;
  color: var(--rule-sand);
}

.page-about .about-head {
  max-width: 760px;
  padding: 30px 0 4px;
}

.page-about .about-head .eyebrow {
  margin: 0 0 14px;
}

.page-about .about-head h1 {
  margin: 0;
  font-size: clamp(30px, 6.2vw, 54px);
  line-height: 1.14;
  letter-spacing: -0.025em;
  font-weight: 800;
  color: var(--ink-navy);
}

.page-about .about-lede {
  margin: 20px 0 0;
  font-size: 17px;
  line-height: 1.78;
  color: var(--ink-navy-70);
}

/* 概况数据条 */
.page-about .about-facts {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: 36px 0 0;
  background: var(--rule-sand);
  border: 1px solid var(--rule-sand);
  border-radius: var(--r-md);
  overflow: hidden;
}

.page-about .about-fact {
  display: flex;
  flex-direction: column;
  gap: 3px;
  padding: 20px 18px 22px;
  background: var(--card-white);
}

.page-about .about-fact__num {
  font-family: var(--mono);
  font-variant-numeric: tabular-nums;
  font-size: 32px;
  line-height: 1.05;
  font-weight: 700;
  color: var(--turf-green);
  letter-spacing: -0.02em;
}

.page-about .about-fact__label {
  font-size: 14px;
  font-weight: 700;
  color: var(--ink-navy);
}

.page-about .about-fact__note {
  font-size: 12px;
  line-height: 1.6;
  letter-spacing: 0.02em;
  color: var(--ink-navy-70);
}

/* 章节骨架 */
.page-about .about-section {
  display: grid;
  grid-template-columns: 1fr;
  gap: 14px;
  padding: 40px 0 8px;
  border-top: 1px solid var(--rule-sand);
  margin-top: 44px;
}

.page-about .about-section__aside {
  display: flex;
  align-items: baseline;
  gap: 12px;
}

.page-about .about-section__no {
  font-family: var(--mono);
  font-variant-numeric: tabular-nums;
  font-size: 30px;
  line-height: 1;
  font-weight: 700;
  color: var(--rule-sand);
  letter-spacing: -0.02em;
}

.page-about .about-section__kicker {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.18em;
  color: var(--ink-navy-70);
}

.page-about .about-section__body h2 {
  margin: 0 0 18px;
  font-size: clamp(22px, 3.4vw, 32px);
  line-height: 1.24;
  letter-spacing: -0.02em;
  font-weight: 800;
  color: var(--ink-navy);
}

.page-about .about-section__body p {
  margin: 0 0 16px;
  font-size: 16px;
  line-height: 1.82;
  color: var(--ink-navy);
}

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

.page-about .about-section__body a {
  color: var(--turf-green);
  text-decoration: underline;
  text-underline-offset: 3px;
  text-decoration-thickness: 1px;
}

.page-about .about-section__body a:hover {
  color: var(--signal-orange);
}

.page-about .about-note {
  font-size: 13px;
  line-height: 1.75;
  letter-spacing: 0.02em;
  color: var(--ink-navy-70);
  padding-left: 14px;
  border-left: 2px solid var(--rule-sand);
}

/* 图片 */
.page-about .about-figure {
  margin: 26px 0 0;
  border-radius: var(--r-lg);
  overflow: hidden;
  background: var(--ink-navy);
}

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

.page-about .about-figure figcaption {
  padding: 12px 20px 14px;
  font-size: 12px;
  line-height: 1.7;
  letter-spacing: 0.02em;
  color: var(--paper-cream);
  background: var(--ink-navy);
}

.page-about .about-figure--tall img {
  aspect-ratio: 4 / 3;
}

.page-about .about-figure--wide {
  margin: 48px 0 0;
}

.page-about .about-figure--wide img {
  aspect-ratio: 16 / 9;
}

/* 流程 SVG */
.page-about .flow {
  margin: 26px 0 24px;
}

.page-about .flow__svg {
  display: block;
  width: 100%;
  height: auto;
}

.page-about .flow__node rect {
  fill: var(--card-white);
  stroke: var(--rule-sand);
  stroke-width: 1;
}

.page-about .flow__node--last rect {
  fill: var(--turf-green);
  stroke: var(--turf-green);
}

.page-about .flow__node text {
  font-family: var(--sans);
  font-size: 15px;
  font-weight: 700;
  fill: var(--ink-navy);
}

.page-about .flow__node--last text {
  fill: var(--card-white);
}

.page-about .flow__link line {
  stroke: var(--rule-sand);
  stroke-width: 1.5;
}

.page-about .flow__link polygon {
  fill: var(--rule-sand);
}

.page-about .flow__cap text {
  font-family: var(--mono);
  font-size: 11.5px;
  fill: var(--ink-navy-70);
  letter-spacing: 0.02em;
}

.page-about .flow figcaption {
  margin-top: 10px;
  font-size: 12px;
  line-height: 1.7;
  letter-spacing: 0.02em;
  color: var(--ink-navy-70);
}

/* 术语表 */
.page-about .terms {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1px;
  margin: 22px 0 26px;
  background: var(--rule-sand);
  border: 1px solid var(--rule-sand);
  border-radius: var(--r-md);
  overflow: hidden;
}

.page-about .term {
  display: grid;
  gap: 7px;
  padding: 16px 18px 18px;
  background: var(--card-white);
}

.page-about .term__key {
  display: inline-block;
  justify-self: start;
  padding: 4px 12px;
  border-radius: var(--r-pill);
  background: var(--paper-deep);
  font-family: var(--mono);
  font-variant-numeric: tabular-nums;
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.02em;
  color: var(--ink-navy);
}

.page-about .term__val {
  font-size: 14px;
  line-height: 1.75;
  color: var(--ink-navy-70);
}

/* 年龄段色例 */
.page-about .tier-legend {
  padding: 20px 20px 18px;
  border-radius: var(--r-md);
  background: var(--paper-deep);
}

.page-about .tier-legend__lead {
  margin: 0 0 14px;
  font-size: 13px;
  line-height: 1.7;
  color: var(--ink-navy);
  font-weight: 700;
}

.page-about .tier-legend__list {
  margin: 0 0 16px;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 10px;
}

.page-about .tier-legend__item {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  font-size: 13px;
  line-height: 1.7;
  color: var(--ink-navy);
}

.page-about .tier-legend__dot {
  flex: none;
  width: 12px;
  height: 12px;
  margin-top: 5px;
  border-radius: 50%;
  background: var(--ink-navy);
}

.page-about .tier-legend__item.u19 .tier-legend__dot { background: var(--tier-u19); }
.page-about .tier-legend__item.u17 .tier-legend__dot { background: var(--tier-u17); }
.page-about .tier-legend__item.u15 .tier-legend__dot { background: var(--tier-u15); }

/* 团队分工 */
.page-about .team-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1px;
  margin: 22px 0 24px;
  background: var(--rule-sand);
  border: 1px solid var(--rule-sand);
  border-radius: var(--r-md);
  overflow: hidden;
}

.page-about .team-cell {
  display: grid;
  grid-template-columns: auto 1fr;
  grid-template-rows: auto auto;
  column-gap: 14px;
  row-gap: 3px;
  padding: 16px 18px 18px;
  background: var(--card-white);
}

.page-about .team-cell__num {
  grid-row: 1 / 3;
  align-self: start;
  font-family: var(--mono);
  font-variant-numeric: tabular-nums;
  font-size: 34px;
  line-height: 1;
  font-weight: 700;
  color: var(--signal-orange);
  letter-spacing: -0.02em;
}

.page-about .team-cell__role {
  font-size: 14px;
  font-weight: 700;
  color: var(--ink-navy);
}

.page-about .team-cell__desc {
  font-size: 12.5px;
  line-height: 1.7;
  color: var(--ink-navy-70);
}

/* 版本演进 */
.page-about .ver {
  margin: 22px 0 22px;
}

.page-about .ver__svg {
  display: block;
  width: 100%;
  height: auto;
}

.page-about .ver__axis {
  stroke: var(--rule-sand);
  stroke-width: 1;
}

.page-about .ver__bar--1 { fill: var(--turf-light); }
.page-about .ver__bar--2 { fill: var(--turf-green); }
.page-about .ver__bar--3 { fill: var(--ink-navy); }

.page-about .ver__tag {
  font-family: var(--mono);
  font-size: 16px;
  font-weight: 700;
  fill: var(--ink-navy);
  letter-spacing: 0.02em;
}

.page-about .ver__bar--2 + .ver__tag,
.page-about .ver__tag:nth-of-type(2) { fill: var(--card-white); }

.page-about .ver__cap {
  font-family: var(--mono);
  font-size: 11.5px;
  fill: var(--ink-navy-70);
  letter-spacing: 0.02em;
}

.page-about .ver figcaption {
  margin-top: 10px;
  font-size: 12px;
  line-height: 1.7;
  letter-spacing: 0.02em;
  color: var(--ink-navy-70);
}

.page-about .ver-fold {
  border: 1px solid var(--rule-sand);
  border-radius: var(--r-md);
  background: var(--card-white);
  overflow: hidden;
}

.page-about .ver-fold > summary {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 16px 20px;
  cursor: pointer;
  list-style: none;
  font-size: 14px;
  font-weight: 700;
  color: var(--ink-navy);
  transition: background 200ms ease-out;
}

.page-about .ver-fold > summary::-webkit-details-marker {
  display: none;
}

.page-about .ver-fold > summary::before {
  content: "";
  flex: none;
  width: 10px;
  height: 10px;
  border-radius: 3px;
  background: var(--rule-sand);
  transition: background 200ms ease-out;
}

.page-about .ver-fold[open] > summary::before {
  background: var(--turf-green);
}

.page-about .ver-fold > summary:hover {
  background: var(--paper-deep);
}

.page-about .ver-fold__body {
  padding: 4px 20px 20px;
  border-top: 1px solid var(--rule-sand);
}

.page-about .ver-list {
  margin: 0;
}

.page-about .ver-list dt {
  margin-top: 16px;
  font-family: var(--mono);
  font-variant-numeric: tabular-nums;
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.02em;
  color: var(--turf-green);
}

.page-about .ver-list dd {
  margin: 6px 0 0;
  font-size: 14px;
  line-height: 1.78;
  color: var(--ink-navy-70);
}

/* 边界列表 */
.page-about .nope {
  margin: 20px 0 22px;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 14px;
}

.page-about .nope li {
  position: relative;
  padding-left: 24px;
  font-size: 15.5px;
  line-height: 1.78;
  color: var(--ink-navy);
}

.page-about .nope li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 11px;
  width: 12px;
  height: 2px;
  background: var(--signal-orange);
}

@media (min-width: 620px) {
  .page-about .about-facts {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

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

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

  .page-about .about-figure--tall img {
    aspect-ratio: 16 / 11;
  }
}

@media (min-width: 900px) {
  .page-about {
    --about-aside-w: 156px;
    --about-gap: 44px;
  }

  .page-about .crumbs {
    padding-top: 38px;
  }

  .page-about .about-head {
    padding: 44px 0 6px;
  }

  .page-about .about-facts {
    margin-top: 48px;
  }

  .page-about .about-section {
    grid-template-columns: var(--about-aside-w) minmax(0, 1fr);
    gap: var(--about-gap);
    padding: 52px 0 12px;
    margin-top: 60px;
  }

  .page-about .about-section__aside {
    flex-direction: column;
    gap: 10px;
    position: sticky;
    top: calc(var(--topbar-h) + 28px);
    align-self: start;
  }

  .page-about .about-section__no {
    font-size: 44px;
  }

  .page-about .about-section__body {
    max-width: 720px;
  }

  .page-about .about-section__body p {
    font-size: 16.5px;
  }

  .page-about .about-figure--tall {
    max-width: 420px;
  }

  .page-about .about-figure--tall img {
    aspect-ratio: 4 / 5;
  }

  .page-about .about-figure--wide {
    margin-top: 60px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .ver-fold > summary,
  .page-about .ver-fold > summary::before {
    transition: none;
  }
}
</style>
<<<END>>>