.page-about {
  --about-pad: clamp(1.15rem, 4vw, 2.6rem);
  --about-card: rgba(25, 27, 38, .82);
  position: relative;
  isolation: isolate;
  color: var(--paper);
  padding-bottom: clamp(3.2rem, 8vw, 6rem);
  overflow-x: clip;
}

.page-about::before {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  top: 0;
  height: min(880px, 115vh);
  background:
    radial-gradient(58% 46% at 24% 10%, rgba(90, 63, 176, .34), transparent 68%),
    radial-gradient(46% 40% at 84% 2%, rgba(59, 75, 216, .24), transparent 72%);
  pointer-events: none;
  z-index: 0;
}

.page-about .about-shell {
  width: 100%;
  max-width: var(--shell);
  margin-inline: auto;
  padding-inline: var(--about-pad);
  position: relative;
  z-index: 1;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  z-index: 1;
  padding-top: calc(var(--frame-top) + clamp(1.6rem, 5vw, 3.2rem));
  padding-bottom: clamp(1.8rem, 4.5vw, 3rem);
}

.page-about .about-hero__grid {
  display: grid;
  gap: clamp(1.8rem, 4vw, 3rem);
}

.page-about .about-hero__eyebrow {
  margin: 1.2rem 0 0;
  color: var(--gold);
}

.page-about .about-hero .display {
  font-family: var(--font-display);
  font-weight: 300;
  font-size: clamp(2.5rem, 7.6vw, 5rem);
  line-height: 1.04;
  letter-spacing: -0.01em;
  color: var(--paper);
  margin: 1rem 0 1.1rem;
  -webkit-text-stroke: 0.6px rgba(212, 164, 76, .42);
  text-shadow: 0 0 40px rgba(212, 164, 76, .16);
}

.page-about .about-hero__lede {
  max-width: 46ch;
  color: var(--mist);
  margin: 0 0 1.6rem;
}

.page-about .about-hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: .7rem;
}

.page-about .about-hero__index {
  border-top: 1px solid var(--line-gold);
  padding-top: 1rem;
}

.page-about .about-hero__list {
  list-style: none;
  margin: .8rem 0 0;
  padding: 0;
  display: grid;
  gap: .1rem;
}

.page-about .about-hero__list a {
  display: flex;
  gap: .7rem;
  align-items: baseline;
  padding: .42rem 0;
  font-size: .88rem;
  line-height: 1.5;
  color: var(--mist);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color .24s var(--ease), border-color .24s var(--ease);
}

.page-about .about-hero__list a:hover,
.page-about .about-hero__list a:focus-visible {
  color: var(--gold-hi);
  border-bottom-color: rgba(212, 164, 76, .42);
}

.page-about .about-hero__list a span {
  font-family: var(--font-mono);
  font-size: .7rem;
  letter-spacing: .16em;
  color: var(--gold);
}

/* ---------- 主体两栏 ---------- */
.page-about .about-body {
  position: relative;
  z-index: 1;
  display: grid;
  gap: clamp(1.2rem, 4vw, 2.6rem);
  padding-top: clamp(1.4rem, 4vw, 2.4rem);
}

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

/* ---------- 章节导航脊 ---------- */
.page-about .about-rail {
  position: relative;
  min-width: 0;
}

.page-about .about-rail__title {
  color: var(--gold);
  margin: 0 0 .9rem;
}

.page-about .about-rail__list {
  list-style: none;
  margin: 0;
  padding: 0 0 0 1.5rem;
  position: relative;
  display: grid;
  gap: .1rem;
}

.page-about .about-rail__list::before {
  content: "";
  position: absolute;
  left: .34rem;
  top: .5rem;
  bottom: .5rem;
  width: 1px;
  background: linear-gradient(180deg,
    rgba(212, 164, 76, 0) 0%,
    rgba(212, 164, 76, .6) 12%,
    rgba(138, 101, 38, .7) 88%,
    rgba(212, 164, 76, 0) 100%);
}

.page-about .about-rail__link {
  position: relative;
  display: flex;
  gap: .65rem;
  align-items: baseline;
  padding: .5rem .6rem .5rem 0;
  font-size: .85rem;
  line-height: 1.45;
  color: var(--mist);
  text-decoration: none;
  transition: color .24s var(--ease);
}

.page-about .about-rail__link::before {
  content: "";
  position: absolute;
  left: -1.16rem;
  top: 50%;
  width: 7px;
  height: 7px;
  margin-top: -3.5px;
  margin-left: -3.5px;
  border-radius: 50%;
  background: var(--ink);
  border: 1px solid var(--gold-deep);
  transition: background .24s var(--ease), border-color .24s var(--ease), box-shadow .24s var(--ease);
}

.page-about .about-rail__link:hover,
.page-about .about-rail__link:focus-visible {
  color: var(--paper);
}

.page-about .about-rail__link:hover::before,
.page-about .about-rail__link:focus-visible::before,
.page-about .about-rail__link.is-active::before {
  background: var(--gold-hi);
  border-color: var(--gold-hi);
  box-shadow: 0 0 14px rgba(244, 215, 148, .75);
}

.page-about .about-rail__link.is-active {
  color: var(--gold-hi);
}

.page-about .about-rail__num {
  font-family: var(--font-mono);
  font-size: .7rem;
  letter-spacing: .14em;
  color: var(--gold);
}

.page-about .about-rail__name {
  display: inline;
}

/* ---------- 章节 ---------- */
.page-about .about-chapter {
  position: relative;
  padding-block: clamp(1.9rem, 5vw, 3.2rem);
}

.page-about .about-chapter + .about-chapter {
  border-top: 1px solid var(--line-gold);
}

.page-about .about-chapter__head {
  margin-bottom: clamp(1.1rem, 3vw, 1.8rem);
}

.page-about .about-chapter__head .eyebrow {
  color: var(--gold);
}

.page-about .about-chapter h2 {
  font-family: var(--font-display);
  font-weight: 400;
  font-size: clamp(1.5rem, 3.6vw, 2.3rem);
  line-height: 1.22;
  letter-spacing: -0.005em;
  color: var(--paper);
  margin: .65rem 0 0;
  max-width: 24ch;
}

.page-about .about-chapter__intro {
  margin: 0 0 clamp(1.2rem, 3vw, 1.8rem);
  max-width: 62ch;
  color: var(--mist);
}

.page-about .about-chapter__note {
  margin: clamp(1.2rem, 3vw, 1.8rem) 0 0;
  max-width: 62ch;
  font-size: .93rem;
  line-height: 1.8;
  color: var(--mist);
  border-left: 1px solid var(--line-gold);
  padding-left: 1rem;
}

.page-about .about-chapter__text p {
  margin: 0 0 1rem;
  max-width: 62ch;
  color: var(--paper);
}

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

.page-about .about-chapter__split {
  display: grid;
  gap: clamp(1.4rem, 4vw, 2.4rem);
  align-items: start;
}

.page-about .about-inline-link {
  color: var(--gold-hi);
  text-underline-offset: 3px;
  text-decoration-color: rgba(212, 164, 76, .5);
}

.page-about .about-inline-link:hover {
  text-decoration-color: var(--gold-hi);
}

/* ---------- 图片 ---------- */
.page-about .about-figure {
  margin: 0;
  position: relative;
}

.page-about .about-figure img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
  background: var(--ink-2);
  border: 1px solid var(--line-gold);
  box-shadow: 0 24px 60px rgba(0, 0, 0, .55);
}

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

.page-about .about-figure--tall img {
  aspect-ratio: 1 / 1;
}

.page-about .about-figure--wide img {
  aspect-ratio: 1200 / 520;
  margin-bottom: clamp(1.4rem, 4vw, 2.2rem);
}

.page-about .about-figure figcaption {
  margin-top: .7rem;
  font-size: .78rem;
  line-height: 1.6;
  letter-spacing: .02em;
  color: var(--mist);
}

/* ---------- 数据卡 ---------- */
.page-about .about-stats {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
  gap: 1px;
  background: var(--line-gold);
  border: 1px solid var(--line-gold);
  box-shadow: 0 22px 50px rgba(0, 0, 0, .45);
}

.page-about .about-stat {
  background: var(--ink-2);
  padding: clamp(1rem, 2.8vw, 1.5rem);
  display: flex;
  flex-direction: column;
  gap: .55rem;
  transition: background .3s var(--ease);
}

.page-about .about-stat:hover {
  background: #14161f;
}

.page-about .about-stat__num {
  margin: 0;
  font-family: var(--font-mono);
  font-size: clamp(1.4rem, 3.6vw, 2.05rem);
  line-height: 1.1;
  letter-spacing: .01em;
  color: var(--gold-hi);
  text-shadow: 0 0 26px rgba(212, 164, 76, .22);
}

.page-about .about-stat__label {
  margin: 0;
  font-size: .82rem;
  line-height: 1.65;
  color: var(--mist);
}

/* ---------- 资料条目 ---------- */
.page-about .about-list {
  list-style: none;
  margin: 0;
  padding: 0;
  border-top: 1px solid var(--line-gold);
}

.page-about .about-list > li {
  display: grid;
  grid-template-columns: 6.2rem minmax(0, 1fr);
  gap: 1rem;
  align-items: baseline;
  padding: .95rem 0;
  border-bottom: 1px solid var(--line-gold);
  font-size: .93rem;
  line-height: 1.8;
  color: var(--paper);
}

.page-about .about-list__key {
  font-family: var(--font-mono);
  font-size: .7rem;
  letter-spacing: .16em;
  color: var(--gold);
}

/* ---------- 协作面板 ---------- */
.page-about .about-panel {
  background: linear-gradient(160deg, rgba(90, 63, 176, .22), rgba(25, 27, 38, .92) 62%);
  border: 1px solid var(--line-gold);
  padding: clamp(1.2rem, 3.2vw, 1.8rem);
  box-shadow: 0 22px 54px rgba(0, 0, 0, .5);
}

.page-about .about-panel__num {
  margin: 0;
  font-family: var(--font-mono);
  font-size: clamp(1.8rem, 5vw, 2.6rem);
  line-height: 1;
  color: var(--gold-hi);
  text-shadow: 0 0 30px rgba(212, 164, 76, .26);
}

.page-about .about-panel__cap {
  margin: .7rem 0 1.1rem;
  font-size: .85rem;
  line-height: 1.7;
  color: var(--mist);
}

.page-about .about-panel__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: .6rem;
}

.page-about .about-panel__list li {
  position: relative;
  padding-left: 1.05rem;
  font-size: .86rem;
  line-height: 1.7;
  color: var(--paper);
}

.page-about .about-panel__list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: .62em;
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: var(--teal);
  box-shadow: 0 0 10px rgba(38, 198, 166, .6);
}

/* ---------- 里程碑 ---------- */
.page-about .about-mile {
  list-style: none;
  margin: 0;
  padding: 0;
  position: relative;
  display: grid;
  gap: clamp(1rem, 2.6vw, 1.5rem);
}

.page-about .about-mile::before {
  content: "";
  position: absolute;
  left: calc(1.1rem - .5px);
  top: .6rem;
  bottom: .6rem;
  width: 1px;
  background: linear-gradient(180deg,
    rgba(212, 164, 76, .06) 0%,
    rgba(212, 164, 76, .55) 18%,
    rgba(138, 101, 38, .6) 82%,
    rgba(212, 164, 76, 0) 100%);
}

.page-about .about-mile__item {
  position: relative;
  display: grid;
  grid-template-columns: 2.2rem minmax(0, 1fr);
  gap: clamp(.8rem, 2.4vw, 1.3rem);
  align-items: start;
}

.page-about .about-mile__badge {
  position: relative;
  z-index: 1;
  width: 2.2rem;
  height: 2.2rem;
  border-radius: 50%;
  display: grid;
  place-items: center;
  font-family: var(--font-mono);
  font-size: .7rem;
  letter-spacing: .06em;
  color: var(--gold-hi);
  background: radial-gradient(circle at 30% 25%, rgba(244, 215, 148, .22), rgba(6, 6, 10, .95) 72%);
  border: 1px solid rgba(212, 164, 76, .45);
  box-shadow: 0 0 0 4px rgba(6, 6, 10, 1), 0 0 18px rgba(212, 164, 76, .14);
  transition: box-shadow .3s var(--ease), border-color .3s var(--ease);
}

.page-about .about-mile__item:hover .about-mile__badge,
.page-about .about-mile__item:focus-within .about-mile__badge {
  border-color: var(--gold-hi);
  box-shadow: 0 0 0 4px rgba(6, 6, 10, 1), 0 0 26px rgba(244, 215, 148, .42);
}

.page-about .about-mile__card {
  background: var(--about-card);
  border: 1px solid var(--line-gold);
  padding: clamp(1rem, 2.6vw, 1.4rem);
  transition: transform .3s var(--ease), border-color .3s var(--ease);
}

.page-about .about-mile__item:hover .about-mile__card,
.page-about .about-mile__item:focus-within .about-mile__card {
  transform: translateX(4px);
  border-color: rgba(212, 164, 76, .45);
}

.page-about .about-mile__card .mono-label {
  color: var(--gold);
}

.page-about .about-mile__card h3 {
  font-family: var(--font-display);
  font-weight: 400;
  font-size: clamp(1.02rem, 2.4vw, 1.26rem);
  line-height: 1.4;
  color: var(--paper);
  margin: .45rem 0 .5rem;
}

.page-about .about-mile__card p {
  margin: 0;
  font-size: .9rem;
  line-height: 1.8;
  color: var(--mist);
}

.page-about .about-mile__note {
  color: var(--gold-hi) !important;
  font-size: .84rem !important;
}

/* ---------- 支持 ---------- */
.page-about .about-support__mail {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: .7rem;
  margin-top: 1.4rem;
  padding-top: 1.1rem;
  border-top: 1px solid var(--line-gold);
}

.page-about .about-support__mail .mono-label {
  color: var(--gold);
}

.page-about .about-support__addr {
  font-family: var(--font-mono);
  font-size: .88rem;
  color: var(--paper);
  word-break: break-all;
}

.page-about .about-support__copy {
  padding: .45rem .9rem;
  font-size: .78rem;
}

/* ---------- 收尾 ---------- */
.page-about .about-cta {
  margin-top: clamp(2rem, 6vw, 3.6rem);
}

.page-about .about-cta__board {
  padding: clamp(1.5rem, 4vw, 2.6rem);
  background:
    radial-gradient(70% 120% at 12% 0%, rgba(59, 75, 216, .2), transparent 66%),
    var(--card);
}

.page-about .about-cta__board .mono-label {
  color: var(--gold);
}

.page-about .about-cta__board h2 {
  font-family: var(--font-display);
  font-weight: 400;
  font-size: clamp(1.4rem, 3.4vw, 2.1rem);
  line-height: 1.25;
  color: var(--paper);
  margin: .7rem 0 .9rem;
  max-width: 22ch;
}

.page-about .about-cta__text {
  margin: 0 0 1.5rem;
  max-width: 62ch;
  font-size: .93rem;
  line-height: 1.85;
  color: var(--mist);
}

.page-about .about-cta__actions {
  display: flex;
  flex-wrap: wrap;
  gap: .7rem;
}

/* ---------- 媒体查询 ---------- */
@media (max-width: 999px) {
  .page-about .about-rail {
    position: sticky;
    top: var(--frame-top);
    z-index: 6;
    margin-inline: calc(-1 * var(--about-pad));
    padding: .55rem var(--about-pad) .7rem;
    background: linear-gradient(180deg,
      rgba(6, 6, 10, .96) 0%,
      rgba(6, 6, 10, .86) 72%,
      rgba(6, 6, 10, 0) 100%);
    backdrop-filter: blur(10px);
  }

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

  .page-about .about-rail__list {
    display: flex;
    gap: .45rem;
    overflow-x: auto;
    padding-left: 0;
    scrollbar-width: none;
  }

  .page-about .about-rail__list::-webkit-scrollbar {
    display: none;
  }

  .page-about .about-rail__list::before {
    display: none;
  }

  .page-about .about-rail__link {
    white-space: nowrap;
    padding: .4rem .8rem;
    font-size: .78rem;
    border: 1px solid var(--line-gold);
    border-radius: 999px;
    background: rgba(25, 27, 38, .72);
  }

  .page-about .about-rail__link::before {
    display: none;
  }

  .page-about .about-rail__link.is-active {
    border-color: rgba(244, 215, 148, .6);
    background: rgba(212, 164, 76, .12);
  }
}

@media (min-width: 820px) {
  .page-about .about-chapter__split {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, .95fr);
  }

  .page-about .about-chapter__split--reverse {
    grid-template-columns: minmax(0, 1fr) minmax(240px, .8fr);
  }
}

@media (min-width: 1000px) {
  .page-about .about-body {
    grid-template-columns: 236px minmax(0, 1fr);
    gap: clamp(2.4rem, 4.5vw, 4.2rem);
    align-items: start;
  }

  .page-about .about-rail {
    position: sticky;
    top: calc(var(--frame-top) + 2rem);
    align-self: start;
  }

  .page-about .about-chapter + .about-chapter {
    padding-top: clamp(2.4rem, 5vw, 3.6rem);
  }
}

@media (min-width: 920px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 1.25fr) minmax(240px, .75fr);
    align-items: end;
  }
}

@media (max-width: 520px) {
  .page-about .about-list > li {
    grid-template-columns: minmax(0, 1fr);
    gap: .3rem;
  }

  .page-about .about-hero__actions .btn,
  .page-about .about-cta__actions .btn {
    flex: 1 1 auto;
    text-align: center;
  }
}

@media (hover: hover) and (min-width: 900px) {
  .page-about .about-mile__note {
    max-height: 0;
    margin-top: 0;
    overflow: hidden;
    opacity: 0;
    transition: max-height .34s var(--ease), opacity .34s var(--ease), margin-top .34s var(--ease);
  }

  .page-about .about-mile__item:hover .about-mile__note,
  .page-about .about-mile__item:focus-within .about-mile__note {
    max-height: 9rem;
    margin-top: .6rem;
    opacity: 1;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-mile__card,
  .page-about .about-mile__badge,
  .page-about .about-stat,
  .page-about .about-rail__link::before {
    transition: none;
  }

  .page-about .about-mile__item:hover .about-mile__card,
  .page-about .about-mile__item:focus-within .about-mile__card {
    transform: none;
  }
}