.page-about{
  --about-rail-top: 96px;
  display: block;
  background: var(--ink);
  color: var(--moss);
  overflow-x: clip;
}

/* ---------- 面包屑 ---------- */
.page-about .crumbs{
  margin-bottom: clamp(20px, 3vw, 32px);
}
.page-about .crumbs__list{
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin: 0;
  padding: 0;
  list-style: none;
  font-size: 12px;
  letter-spacing: .1em;
  color: var(--moss);
}
.page-about .crumbs__list li + li::before{
  content: "/";
  margin-right: 10px;
  color: var(--glass);
}
.page-about .crumbs__a{
  color: var(--moss);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color 200ms var(--ease), border-color 200ms var(--ease);
}
.page-about .crumbs__a:hover,
.page-about .crumbs__a:focus-visible{
  color: var(--cyan);
  border-bottom-color: var(--cyan-40);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero{
  position: relative;
  overflow: hidden;
  padding: clamp(16px, 3vw, 28px) 0 clamp(40px, 7vw, 84px);
  background:
    radial-gradient(90% 120% at 92% -10%, rgb(43 240 196 / .14), transparent 62%),
    linear-gradient(180deg, var(--ink) 0%, var(--char) 100%);
  border-bottom: 1px solid var(--line);
}
.page-about .about-hero::before{
  content: "";
  position: absolute;
  right: -8%;
  top: -40%;
  width: min(620px, 72vw);
  height: 180%;
  z-index: 0;
  background: linear-gradient(140deg, rgb(43 240 196 / .12), rgb(111 216 255 / .05) 45%, transparent 72%);
  clip-path: polygon(42% 0, 100% 0, 64% 100%, 0 100%);
  pointer-events: none;
}
.page-about .about-hero__grid{
  position: relative;
  z-index: 1;
  display: grid;
  gap: clamp(24px, 4vw, 48px);
  align-items: start;
}
.page-about h1{
  margin: 12px 0 0;
  font-family: var(--font-display);
  font-size: clamp(2rem, 5.4vw, 3.5rem);
  line-height: 1.1;
  letter-spacing: .06em;
  font-weight: 700;
  color: var(--mist);
  max-width: 15em;
}
.page-about .lede{
  margin: 18px 0 0;
  max-width: 40em;
  font-size: clamp(15px, 1.6vw, 17px);
  line-height: 1.78;
  letter-spacing: .01em;
  color: var(--moss);
}
.page-about .about-hero__panel{
  display: grid;
  gap: 2px;
  padding: clamp(16px, 2.4vw, 26px);
  background: var(--glass-40);
  border: 1px solid var(--line);
  border-left: 2px solid var(--cyan-40);
}
.page-about .about-kv{
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 16px;
  padding: 10px 0;
  border-bottom: 1px dashed var(--line-soft);
}
.page-about .about-kv:last-child{
  border-bottom: 0;
  padding-bottom: 0;
}
.page-about .about-kv__k{
  font-size: 12px;
  letter-spacing: .12em;
  color: var(--moss);
}
.page-about .about-kv__v{
  font-family: var(--font-mono);
  font-size: clamp(1.1rem, 2.2vw, 1.35rem);
  letter-spacing: .02em;
  color: var(--cyan);
  white-space: nowrap;
}
.page-about .about-kv:first-child .about-kv__v{
  color: var(--mist);
}

/* ---------- 主体分栏 ---------- */
.page-about .about-body{
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(24px, 4vw, 56px);
  padding-block: clamp(32px, 6vw, 64px);
}

/* 版本导轨 */
.page-about .about-rail__title{
  margin: 0 0 12px;
  font-size: 12px;
  letter-spacing: .16em;
  color: var(--moss);
  text-transform: uppercase;
}
.page-about .about-rail__inner{
  display: flex;
  gap: 8px;
  overflow-x: auto;
  padding-bottom: 8px;
  scrollbar-width: thin;
  -webkit-overflow-scrolling: touch;
}
.page-about .rail__link{
  flex: 0 0 auto;
  display: inline-flex;
  align-items: baseline;
  gap: 8px;
  padding: 9px 14px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  text-decoration: none;
  background: rgb(16 36 29 / .35);
  transition: background 200ms var(--ease), border-color 200ms var(--ease);
}
.page-about .rail__year{
  font-family: var(--font-mono);
  font-size: 1rem;
  letter-spacing: .02em;
  color: var(--mist);
  transition: color 200ms var(--ease);
}
.page-about .rail__label{
  font-size: 12px;
  letter-spacing: .08em;
  color: var(--moss);
}
.page-about .rail__link:hover,
.page-about .rail__link:focus-visible{
  border-color: var(--cyan-40);
  background: var(--cyan-08);
}
.page-about .rail__link:focus-visible{
  outline: 2px solid var(--cyan);
  outline-offset: 2px;
}
.page-about .rail__link[aria-current="true"]{
  border-color: var(--cyan-40);
  background: var(--cyan-08);
}
.page-about .rail__link[aria-current="true"] .rail__year{
  color: var(--cyan);
}

/* ---------- 叙事画布 ---------- */
.page-about .about-canvas{
  min-width: 0;
}
.page-about .about-sec{
  padding-block: clamp(28px, 4.5vw, 52px);
  border-top: 1px solid var(--line);
}
.page-about .about-sec:first-child{
  border-top: 0;
  padding-top: 0;
}
.page-about .about-sec--tint{
  background: var(--pine);
  padding-inline: clamp(16px, 3vw, 30px);
  border-top-color: transparent;
}
.page-about .about-sec__head{
  margin-bottom: clamp(16px, 2.5vw, 24px);
}
.page-about .about-sec h2{
  margin: 8px 0 0;
  font-family: var(--font-display);
  font-size: clamp(1.45rem, 3.2vw, 2.05rem);
  line-height: 1.22;
  letter-spacing: .04em;
  font-weight: 600;
  color: var(--mist);
}
.page-about .about-sec p{
  margin: 0 0 14px;
  max-width: 40em;
  font-size: clamp(15px, 1.5vw, 16.5px);
  line-height: 1.78;
  color: var(--moss);
}
.page-about .about-sec p strong{
  color: var(--mist);
  font-weight: 600;
}
.page-about .about-sec__head p{
  margin-top: 12px;
}

/* 用法列表 */
.page-about .about-uses{
  list-style: none;
  margin: 0 0 6px;
  padding: 0;
  display: grid;
  gap: 10px;
}
.page-about .about-uses li{
  position: relative;
  padding-left: 22px;
  font-size: 15px;
  line-height: 1.7;
  color: var(--moss);
}
.page-about .about-uses li::before{
  content: "";
  position: absolute;
  left: 0;
  top: .78em;
  width: 10px;
  height: 1px;
  background: var(--cyan);
}

/* 旧版资料框 */
.page-about .about-fields{
  margin-top: 22px;
  background: var(--paper);
  color: #16201b;
  padding: 14px clamp(14px, 2.5vw, 22px);
  border-left: 3px solid var(--cyan);
}
.page-about .about-fields summary{
  display: flex;
  align-items: center;
  gap: 10px;
  list-style: none;
  cursor: pointer;
  font-size: 14px;
  font-weight: 600;
  letter-spacing: .04em;
  color: #16201b;
}
.page-about .about-fields summary::-webkit-details-marker{
  display: none;
}
.page-about .about-fields summary::before{
  content: "+";
  font-family: var(--font-mono);
  font-size: 16px;
  line-height: 1;
  color: #12684f;
}
.page-about .about-fields[open] summary::before{
  content: "–";
}
.page-about .about-fields summary:focus-visible{
  outline: 2px solid #12684f;
  outline-offset: 3px;
}
.page-about .about-fields dl{
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 4px;
  margin: 14px 0 2px;
  font-size: 13.5px;
}
.page-about .about-fields dt{
  font-weight: 600;
  color: #16201b;
  margin-top: 8px;
}
.page-about .about-fields dd{
  margin: 0;
  line-height: 1.62;
  color: #42534b;
}

/* 图片 */
.page-about .about-figure{
  margin: clamp(18px, 3vw, 28px) 0 0;
}
.page-about .about-figure img{
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  border: 1px solid var(--line);
  background: var(--panel);
  object-fit: cover;
}
.page-about .about-figure figcaption{
  margin-top: 8px;
  font-size: 12px;
  line-height: 1.6;
  letter-spacing: .06em;
  color: var(--moss);
}

/* 年份叙事 */
.page-about .about-years{
  margin-top: clamp(12px, 2vw, 20px);
}
.page-about .about-year{
  position: relative;
  padding: clamp(16px, 2.4vw, 24px) clamp(14px, 2.4vw, 24px) clamp(16px, 2.4vw, 24px) clamp(20px, 3vw, 30px);
  border-left: 1px solid var(--line);
}
.page-about .about-year:nth-child(even){
  background: rgb(16 36 29 / .55);
}
.page-about .about-year::before{
  content: "";
  position: absolute;
  left: -4px;
  top: clamp(22px, 3vw, 32px);
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--cyan);
  box-shadow: 0 0 0 4px var(--cyan-08);
}
.page-about .about-year--key::before{
  background: var(--orange);
  box-shadow: 0 0 0 4px var(--orange-10);
}
.page-about .about-year__num{
  margin: 0;
  font-family: var(--font-mono);
  font-size: clamp(1.5rem, 3.2vw, 2rem);
  line-height: 1;
  letter-spacing: .02em;
  color: var(--cyan);
}
.page-about .about-year--key .about-year__num{
  color: var(--orange);
}
.page-about .about-year h3{
  margin: 10px 0 8px;
  font-family: var(--font-display);
  font-size: clamp(1.05rem, 2vw, 1.25rem);
  letter-spacing: .05em;
  font-weight: 600;
  color: var(--mist);
}
.page-about .about-year p{
  margin: 0;
  max-width: 42em;
}
.page-about .about-band{
  margin: clamp(16px, 3vw, 26px) 0;
  position: relative;
}
.page-about .about-band img{
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  object-fit: cover;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}
.page-about .about-band figcaption{
  margin-top: 8px;
  font-size: 12px;
  letter-spacing: .06em;
  color: var(--moss);
}

/* 数据团队 */
.page-about .about-team{
  display: grid;
  gap: clamp(18px, 3vw, 28px);
}
.page-about .about-team p{
  margin-bottom: 14px;
}
.page-about .about-quote{
  margin: 20px 0 0;
  padding: 16px 18px;
  background: var(--glass-40);
  border-left: 2px solid var(--cyan);
  color: var(--mist);
  font-size: 15px;
  line-height: 1.72;
  letter-spacing: .02em;
}
.page-about .about-figure--team{
  margin-top: 0;
}

/* 新旧衔接的按钮组 */
.page-about .about-links{
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 22px;
}

/* 运营指标 */
.page-about .about-metrics{
  display: grid;
  gap: clamp(16px, 2.5vw, 28px);
  margin-top: 20px;
}
.page-about .about-metric{
  padding-top: 16px;
  border-top: 2px solid var(--cyan-40);
}
.page-about .about-metric__v{
  margin: 0;
  font-family: var(--font-mono);
  font-size: clamp(1.6rem, 3.6vw, 2.3rem);
  line-height: 1;
  letter-spacing: .02em;
  color: var(--mist);
}
.page-about .about-metric__v em{
  font-style: normal;
  font-size: .45em;
  letter-spacing: .04em;
  color: var(--moss);
  margin-left: 6px;
}
.page-about .about-metric__k{
  display: block;
  margin-top: 12px;
  font-size: 12px;
  letter-spacing: .14em;
  color: var(--cyan);
}
.page-about .about-metric p{
  margin: 10px 0 0;
  font-size: 14px;
  line-height: 1.72;
  color: var(--moss);
}

/* ---------- 结尾行动区 ---------- */
.page-about .about-cta{
  position: relative;
  overflow: hidden;
  margin-top: clamp(24px, 5vw, 56px);
  padding: clamp(36px, 6vw, 72px) 0;
  border-top: 1px solid var(--line);
  background: linear-gradient(115deg, var(--pine) 0%, var(--char) 58%, var(--ink) 100%);
}
.page-about .about-cta::before{
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(100deg, rgb(43 240 196 / .13), transparent 48%);
  clip-path: polygon(0 0, 58% 0, 34% 100%, 0 100%);
  pointer-events: none;
}
.page-about .about-cta__inner{
  position: relative;
  z-index: 1;
  display: grid;
  gap: 22px;
}
.page-about .about-cta h2{
  margin: 8px 0 0;
  font-family: var(--font-display);
  font-size: clamp(1.4rem, 3vw, 2rem);
  line-height: 1.22;
  letter-spacing: .05em;
  font-weight: 600;
  color: var(--mist);
}
.page-about .about-cta p{
  margin: 12px 0 0;
  max-width: 36em;
  font-size: 15px;
  line-height: 1.75;
  color: var(--moss);
}
.page-about .about-cta__actions{
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

/* ---------- 响应式 ---------- */
@media (min-width: 760px){
  .page-about .about-team{
    grid-template-columns: minmax(0, 1.1fr) minmax(0, .9fr);
    align-items: start;
  }
  .page-about .about-metrics{
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
  .page-about .about-fields dl{
    grid-template-columns: max-content minmax(0, 1fr);
    gap: 8px 18px;
    align-items: baseline;
  }
  .page-about .about-fields dt{
    margin-top: 0;
    white-space: nowrap;
  }
}

@media (min-width: 820px){
  .page-about .about-cta__inner{
    grid-template-columns: minmax(0, 1fr) auto;
    align-items: end;
  }
}

@media (min-width: 900px){
  .page-about .about-hero__grid{
    grid-template-columns: minmax(0, 1.25fr) minmax(270px, .75fr);
    align-items: end;
  }
}

@media (min-width: 980px){
  .page-about .about-body{
    grid-template-columns: minmax(210px, .68fr) minmax(0, 1.45fr);
    align-items: start;
  }
  .page-about .about-rail{
    position: sticky;
    top: var(--about-rail-top);
    align-self: start;
  }
  .page-about .about-rail__inner{
    flex-direction: column;
    gap: 0;
    overflow: visible;
    padding-bottom: 0;
    position: relative;
  }
  .page-about .about-rail__inner::before{
    content: "";
    position: absolute;
    left: 0;
    top: 14px;
    bottom: 14px;
    width: 1px;
    background: var(--line);
  }
  .page-about .rail__link{
    width: 100%;
    border: 0;
    border-radius: 0;
    background: transparent;
    padding: 13px 0 13px 22px;
    position: relative;
  }
  .page-about .rail__link::before{
    content: "";
    position: absolute;
    left: -4px;
    top: 50%;
    transform: translateY(-50%);
    width: 7px;
    height: 7px;
    border-radius: 50%;
    background: var(--glass);
    border: 1px solid var(--line);
    transition: background 200ms var(--ease), box-shadow 200ms var(--ease);
  }
  .page-about .rail__link--key::before{
    background: var(--orange);
    border-color: var(--orange);
  }
  .page-about .rail__link[aria-current="true"]{
    background: transparent;
  }
  .page-about .rail__link[aria-current="true"]::before{
    background: var(--cyan);
    border-color: var(--cyan);
    box-shadow: 0 0 0 5px var(--cyan-08);
  }
  .page-about .rail__link[aria-current="true"] .rail__label{
    color: var(--mist);
  }
  .page-about .rail__link:hover{
    background: transparent;
  }
}

@media (min-width: 1180px){
  .page-about .about-sec{
    padding-block: clamp(36px, 4vw, 56px);
  }
}

@media (prefers-reduced-motion: reduce){
  .page-about *{
    transition-duration: .01ms !important;
    animation-duration: .01ms !important;
  }
}
</main>