.page-about {
  background: var(--venue);
  color: var(--ivory);
}

.page-about img {
  max-width: 100%;
  height: auto;
}

/* ---------- 页头 ---------- */

.page-about .about-hero {
  position: relative;
  overflow: hidden;
  background: linear-gradient(158deg, var(--moss) 0%, var(--venue) 62%);
  border-bottom: 1px solid var(--line-soft);
}

.page-about .about-hero__bg {
  position: absolute;
  inset: 0;
  opacity: .22;
}

.page-about .about-hero__bg img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  filter: grayscale(.5) contrast(1.08);
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  top: -34%;
  right: -16%;
  width: 56%;
  height: 178%;
  background: linear-gradient(168deg, rgba(47, 138, 114, .26), rgba(47, 138, 114, 0) 64%);
  transform: rotate(13deg);
  clip-path: polygon(0 0, 100% 0, 100% 100%, 22% 100%);
  pointer-events: none;
}

.page-about .about-hero__inner {
  position: relative;
  z-index: 1;
  padding-block: 44px 56px;
}

.page-about .about-hero h1 {
  margin: 22px 0 20px;
  max-width: 17em;
  font-size: clamp(1.7rem, 5.2vw, 3rem);
  font-weight: 700;
  line-height: 1.24;
  letter-spacing: -0.02em;
  color: var(--ivory);
}

.page-about .about-hero__lede {
  margin: 0 0 28px;
  max-width: 44em;
  font-size: 16.5px;
  line-height: 1.85;
  color: rgba(237, 233, 223, .8);
}

.page-about .hero-marks {
  display: flex;
  flex-wrap: wrap;
  gap: 10px 28px;
  margin: 0 0 30px;
  padding: 0;
  list-style: none;
}

.page-about .hero-marks li {
  display: flex;
  align-items: baseline;
  gap: 8px;
  font-size: 12.5px;
  letter-spacing: .08em;
  color: var(--stone);
}

.page-about .hero-marks .num {
  font-size: 17px;
  color: var(--ivory);
  letter-spacing: -0.01em;
}

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

/* ---------- 主布局与左侧刻度 ---------- */

.page-about .about-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 40px;
  padding-block: 56px 0;
}

.page-about .about-axis {
  display: none;
}

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

@media (min-width: 1000px) {
  .page-about .about-layout {
    grid-template-columns: 124px minmax(0, 1fr);
    gap: 60px;
    padding-block: 88px 0;
  }

  .page-about .about-axis {
    display: block;
    position: sticky;
    top: calc(var(--bar-h) + 36px);
    align-self: start;
  }

  .page-about .about-hero__inner {
    padding-block: 76px 92px;
  }
}

.page-about .about-axis__list {
  position: relative;
  display: grid;
  gap: 32px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .about-axis__list::before {
  content: "";
  position: absolute;
  left: 6px;
  top: 9px;
  bottom: 9px;
  width: 1px;
  background: linear-gradient(180deg, var(--teal) 0%, var(--teal) 20%, var(--rock) 58%, rgba(63, 75, 69, .18) 100%);
}

.page-about .about-axis__node {
  display: grid;
  grid-template-columns: 12px minmax(0, 1fr);
  align-items: center;
  gap: 9px;
  text-decoration: none;
  color: var(--stone);
  font-size: 12px;
  letter-spacing: .1em;
  transition: color .24s var(--ease), transform .24s var(--ease);
}

.page-about .about-axis__node:hover {
  color: var(--ivory);
  transform: translateX(4px);
}

.page-about .about-axis__dot {
  justify-self: center;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--rock);
  box-shadow: 0 0 0 4px var(--venue);
  transition: background .24s var(--ease), transform .24s var(--ease);
}

.page-about .about-axis__node[aria-current="true"] {
  color: var(--ivory);
}

.page-about .about-axis__node[aria-current="true"] .about-axis__dot {
  background: var(--teal);
  transform: scale(1.6);
}

/* ---------- 区块 ---------- */

.page-about .pa-sec {
  padding-block: 48px;
  border-top: 1px solid var(--line-soft);
}

.page-about .pa-sec:first-child {
  border-top: 0;
  padding-top: 0;
}

.page-about .pa-head {
  margin-bottom: 22px;
}

.page-about .pa-index {
  display: block;
  margin-bottom: 12px;
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: .2em;
  color: var(--teal);
}

.page-about .pa-sec h2 {
  margin: 0;
  font-size: clamp(1.32rem, 3.4vw, 1.9rem);
  font-weight: 700;
  line-height: 1.34;
  letter-spacing: -0.02em;
  color: var(--ivory);
}

.page-about .pa-sec p {
  margin: 0 0 16px;
  max-width: 46em;
  font-size: 16.5px;
  line-height: 1.82;
  color: rgba(237, 233, 223, .76);
}

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

.page-about .pa-sec strong {
  color: var(--ivory);
  font-weight: 600;
}

.page-about .pa-sec a {
  color: var(--teal);
  text-decoration: none;
  border-bottom: 1px solid rgba(47, 138, 114, .45);
  transition: color .2s var(--ease), border-color .2s var(--ease);
}

.page-about .pa-sec a:hover {
  color: var(--ivory);
  border-bottom-color: var(--ivory);
}

/* ---------- 年份带 ---------- */

.page-about .year-line {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: 30px 0 0;
  padding: 0;
  list-style: none;
  background: var(--line-soft);
  border: 1px solid var(--line-soft);
}

.page-about .year-line li {
  position: relative;
  padding: 20px 16px 24px;
  background: linear-gradient(180deg, var(--moss), var(--venue));
}

.page-about .year-line li::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 2px;
  background: linear-gradient(90deg, var(--rock), var(--teal));
  opacity: .55;
}

.page-about .year-line li:last-child::after {
  background: linear-gradient(90deg, var(--warn), var(--teal));
  opacity: .85;
}

.page-about .year-line__year {
  display: block;
  margin-bottom: 8px;
  font-family: var(--mono);
  font-size: 26px;
  line-height: 1;
  letter-spacing: -0.01em;
  color: var(--ivory);
}

.page-about .year-line__stage {
  display: block;
  font-size: 12.5px;
  line-height: 1.6;
  letter-spacing: .04em;
  color: var(--stone);
}

@media (min-width: 720px) {
  .page-about .year-line {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

/* ---------- 数字锚点 ---------- */

.page-about .anchors {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
  gap: 1px;
  margin: 28px 0 30px;
  background: var(--line-soft);
  border-block: 1px solid var(--line-soft);
}

.page-about .anchor {
  padding: 24px 20px 22px;
  background: var(--venue);
}

.page-about .anchor__num {
  display: block;
  margin-bottom: 12px;
  font-family: var(--mono);
  font-size: clamp(2rem, 5.4vw, 3.4rem);
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--ivory);
}

.page-about .anchor__unit {
  margin-left: 6px;
  font-size: .34em;
  letter-spacing: .06em;
  color: var(--stone);
}

.page-about .anchor__label {
  display: block;
  font-size: 12.5px;
  letter-spacing: .12em;
  color: var(--stone);
}

/* ---------- 三个查询角度 ---------- */

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

.page-about .dim {
  padding: 22px 20px;
  background: var(--venue);
}

.page-about .dim__key {
  display: inline-block;
  margin-bottom: 14px;
  padding: 3px 9px;
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: .14em;
  color: var(--teal);
  border: 1px solid rgba(47, 138, 114, .45);
}

.page-about .dim__desc {
  display: block;
  font-size: 15px;
  line-height: 1.76;
  color: rgba(237, 233, 223, .75);
}

@media (min-width: 760px) {
  .page-about .dim-list {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

/* ---------- 配图 ---------- */

.page-about .pa-figure {
  margin: 32px 0 4px;
  border: 1px solid var(--line-soft);
  background: var(--moss);
  overflow: hidden;
}

.page-about .pa-figure img {
  display: block;
  width: 100%;
  object-fit: cover;
  opacity: .9;
}

.page-about .pa-figure figcaption {
  padding: 12px 16px;
  border-top: 1px solid var(--line-soft);
  font-size: 12.5px;
  line-height: 1.7;
  letter-spacing: .04em;
  color: var(--stone);
}

/* ---------- 使用场景 ---------- */

.page-about .scene-list {
  display: grid;
  gap: 26px;
  margin: 28px 0 26px;
  padding: 0;
  list-style: none;
}

.page-about .scene {
  padding-top: 18px;
  border-top: 2px solid var(--rock);
  transition: border-color .24s var(--ease);
}

.page-about .scene:hover {
  border-top-color: var(--teal);
}

.page-about .scene__title {
  margin: 0 0 10px;
  font-size: 1rem;
  font-weight: 600;
  letter-spacing: -0.01em;
  color: var(--ivory);
}

.page-about .scene p {
  margin: 0;
  max-width: none;
  font-size: 15px;
  line-height: 1.78;
  color: rgba(237, 233, 223, .72);
}

@media (min-width: 820px) {
  .page-about .scene-list {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 30px;
  }
}

/* ---------- 下一步链接 ---------- */

.page-about .next-links {
  display: grid;
  gap: 1px;
  margin: 28px 0 0;
  padding: 0;
  list-style: none;
  background: var(--line-soft);
  border: 1px solid var(--line-soft);
}

.page-about .next-links a {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 14px;
  padding: 18px;
  font-size: 15px;
  color: var(--ivory);
  text-decoration: none;
  background: var(--venue);
  border-bottom: 0;
  transition: background .24s var(--ease), color .24s var(--ease);
}

.page-about .next-links a:hover {
  background: var(--moss);
  color: var(--teal);
  border-bottom-color: transparent;
}

.page-about .next-links a span {
  flex: none;
  font-family: var(--mono);
  font-size: 11.5px;
  letter-spacing: .12em;
  color: var(--stone);
}

@media (min-width: 700px) {
  .page-about .next-links {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

/* ---------- 收尾留白 ---------- */

.page-about .about-stream {
  padding-bottom: 72px;
}

@media (min-width: 1000px) {
  .page-about .about-stream {
    padding-bottom: 120px;
  }
}

/* ---------- 减弱动效 ---------- */

@media (prefers-reduced-motion: reduce) {
  .page-about .about-axis__node,
  .page-about .about-axis__dot,
  .page-about .scene,
  .page-about .next-links a,
  .page-about .pa-sec a {
    transition: none;
  }

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