.page-about {
  --about-rail: 190px;
  --about-gap: clamp(1.5rem, 4vw, 3rem);
  display: block;
}

/* ---------- 面包屑 ---------- */
.page-about .about-crumbs {
  max-width: var(--shell);
  margin: 0 auto;
  padding: clamp(1rem, 3vw, 1.6rem) var(--gutter) 0;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  padding: clamp(1.5rem, 4vw, 3rem) 0 clamp(2rem, 5vw, 3.25rem);
}

.page-about .about-hero__grid {
  display: grid;
  gap: clamp(2rem, 5vw, 3.5rem);
  align-items: center;
}

.page-about .about-hero__tag {
  display: inline-block;
  margin: 0 0 1rem;
  font-family: var(--font-mono);
  font-size: .72rem;
  letter-spacing: .18em;
  color: var(--c-cyan);
  padding: .3rem .7rem;
  border: 1px solid var(--c-line);
  border-radius: 999px;
  background: rgba(41, 240, 222, .06);
}

.page-about .about-hero h1 {
  margin: 0 0 1.1rem;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(1.9rem, 6.2vw, 3.35rem);
  line-height: 1.14;
  letter-spacing: -.02em;
  color: var(--c-ink);
}

.page-about .about-hero__lead {
  margin: 0 0 1.9rem;
  max-width: 46ch;
  font-size: clamp(1rem, 2.2vw, 1.1rem);
  line-height: 1.85;
  color: var(--c-muted);
}

.page-about .about-hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: .75rem;
}

/* 纯 CSS 主题视觉 */
.page-about .about-orbit {
  position: relative;
  width: 100%;
  max-width: 380px;
  aspect-ratio: 1 / 1;
  margin: 1rem auto 3rem;
}

.page-about .about-orbit__ring {
  position: absolute;
  inset: 0;
  border: 1px solid var(--c-line);
  border-radius: 50%;
}

.page-about .about-orbit__ring--mid {
  inset: 13%;
  border-style: dashed;
  border-color: rgba(41, 240, 222, .34);
  animation: about-spin 30s linear infinite;
}

.page-about .about-orbit__ring--inner {
  inset: 28%;
  border-color: rgba(138, 92, 255, .42);
}

.page-about .about-orbit__core {
  position: absolute;
  inset: 40%;
  border-radius: 50%;
  background:
    radial-gradient(circle at 36% 30%,
      rgba(41, 240, 222, .95) 0%,
      rgba(138, 92, 255, .42) 56%,
      rgba(6, 10, 28, 0) 74%);
  box-shadow: var(--glow-cyan);
  animation: about-breathe 2.4s ease-in-out infinite;
}

.page-about .about-orbit__node {
  position: absolute;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--c-cyan);
  box-shadow: var(--glow-cyan);
}

.page-about .about-orbit__node--n { top: -4px; left: calc(50% - 4px); }
.page-about .about-orbit__node--e {
  right: -4px;
  top: calc(50% - 4px);
  background: var(--c-violet);
  box-shadow: var(--glow-violet);
}
.page-about .about-orbit__node--s {
  bottom: -4px;
  left: calc(50% - 4px);
  background: var(--c-mint);
  box-shadow: none;
}
.page-about .about-orbit__node--w {
  left: -4px;
  top: calc(50% - 4px);
  background: var(--c-glow);
  box-shadow: none;
}

.page-about .about-orbit__readout {
  position: absolute;
  left: 50%;
  bottom: -1.9rem;
  transform: translateX(-50%);
  white-space: nowrap;
  font-family: var(--font-mono);
  font-size: .68rem;
  letter-spacing: .14em;
  color: var(--c-muted);
}

/* ---------- 主体两栏骨架 ---------- */
.page-about .about-layout {
  display: grid;
  gap: var(--about-gap);
  align-items: start;
}

/* ---------- 章节索引 ---------- */
.page-about .about-index {
  border: 1px solid var(--c-line);
  border-radius: var(--r-md);
  background: var(--c-panel);
  padding: .85rem 1rem;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
}

.page-about .about-index__label {
  margin: 0 0 .55rem;
  font-family: var(--font-mono);
  font-size: .68rem;
  letter-spacing: .2em;
  color: var(--c-muted);
}

.page-about .about-index__list {
  display: flex;
  gap: 1.25rem;
  margin: 0;
  padding: 0;
  list-style: none;
  white-space: nowrap;
}

.page-about .about-index__link {
  display: inline-flex;
  align-items: baseline;
  gap: .45rem;
  padding: .25rem 0;
  font-size: .85rem;
  color: var(--c-muted);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.page-about .about-index__link .mono {
  font-family: var(--font-mono);
  font-size: .7rem;
  color: var(--c-line);
}

.page-about .about-index__link:hover,
.page-about .about-index__link.is-active {
  color: var(--c-cyan);
  border-bottom-color: var(--c-cyan);
}

.page-about .about-index__link.is-active .mono {
  color: var(--c-cyan);
}

/* ---------- 章节通用 ---------- */
.page-about .about-section {
  padding-block: clamp(2rem, 5vw, 3.25rem);
  border-top: 1px solid var(--c-line);
}

.page-about .about-head {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: .35rem .85rem;
  align-items: baseline;
  margin-bottom: clamp(1.25rem, 3vw, 2rem);
}

.page-about .about-head .section-note {
  grid-column: 2;
  margin: 0;
  font-family: var(--font-mono);
  font-size: .72rem;
  letter-spacing: .1em;
  color: var(--c-muted);
}

.page-about .about-section p {
  max-width: 62ch;
  line-height: 1.85;
  color: var(--c-muted);
}

.page-about .about-lede {
  margin: 0 0 1.75rem;
  font-size: 1.02rem;
}

/* ---------- 01 自述 ---------- */
.page-about .about-split {
  display: grid;
  gap: clamp(1.5rem, 4vw, 2.5rem);
  align-items: start;
}

.page-about .about-split__body p:first-child {
  margin-top: 0;
}

.page-about .about-stats {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(8.5rem, 1fr));
  gap: 1px;
  margin-top: 1.9rem;
  padding: 1px;
  background: var(--c-line);
  border: 1px solid var(--c-line);
  border-radius: var(--r-md);
  overflow: hidden;
}

.page-about .about-stats .stat {
  display: flex;
  flex-direction: column;
  gap: .3rem;
  padding: 1rem 1.05rem;
  background: var(--c-panel);
}

.page-about .about-stats .stat-value {
  font-family: var(--font-mono);
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--c-glow);
  letter-spacing: -.01em;
}

.page-about .about-stats .stat-label {
  font-size: .78rem;
  color: var(--c-muted);
}

.page-about .about-shot {
  margin: 0;
  border: 1px solid var(--c-line);
  border-radius: var(--r-lg);
  background: var(--c-panel);
  overflow: hidden;
  box-shadow: var(--shadow-card);
}

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

.page-about .about-shot--square {
  max-width: 420px;
  margin-inline: auto;
}

.page-about .about-shot--wide {
  margin-top: clamp(1.75rem, 4vw, 2.5rem);
}

/* ---------- 02 时间轴 ---------- */
.page-about .about-timeline {
  position: relative;
  margin: 0;
  padding: 0 0 0 1.75rem;
  list-style: none;
  border-left: 1px solid var(--c-line);
}

.page-about .about-stage {
  position: relative;
  padding-bottom: 1.85rem;
}

.page-about .about-stage:last-child {
  padding-bottom: 0;
}

.page-about .about-stage__anchor {
  position: absolute;
  inset: -1rem 0 auto -1.75rem;
  height: 1px;
  overflow: hidden;
  text-indent: -999px;
}

.page-about .about-stage__node {
  position: absolute;
  left: -1.75rem;
  top: .45rem;
  width: 9px;
  height: 9px;
  margin-left: -4.5px;
  border-radius: 50%;
  background: var(--c-panel);
  border: 1px solid var(--c-cyan);
  box-shadow: var(--glow-cyan);
}

.page-about .about-stage__no {
  display: block;
  margin-bottom: .35rem;
  font-family: var(--font-mono);
  font-size: .7rem;
  letter-spacing: .16em;
  color: var(--c-violet);
}

.page-about .about-stage__title {
  margin: 0 0 .5rem;
  font-size: clamp(1.02rem, 2.4vw, 1.2rem);
  font-weight: 800;
  color: var(--c-ink);
}

.page-about .about-stage__text {
  margin: 0;
  font-size: .95rem;
}

/* ---------- 03 团队 ---------- */
.page-about .about-team {
  display: grid;
  gap: clamp(1.5rem, 4vw, 2.5rem);
  align-items: center;
  margin-bottom: clamp(1.75rem, 4vw, 2.5rem);
}

.page-about .about-donut {
  position: relative;
  width: min(240px, 66vw);
  aspect-ratio: 1 / 1;
  margin-inline: auto;
}

.page-about .about-donut__ring {
  position: absolute;
  inset: 0;
  border-radius: 50%;
  background: conic-gradient(
    var(--c-cyan) 0 16.3%,
    var(--c-violet) 16.3% 41.9%,
    var(--c-mint) 41.9% 60.5%,
    var(--c-line) 60.5% 100%
  );
}

.page-about .about-donut__hole {
  position: absolute;
  inset: 24%;
  border-radius: 50%;
  background: var(--c-panel);
  display: grid;
  place-content: center;
  text-align: center;
}

.page-about .about-donut__num {
  font-family: var(--font-mono);
  font-size: 2rem;
  font-weight: 700;
  line-height: 1;
  color: var(--c-glow);
}

.page-about .about-donut__unit {
  font-size: .78rem;
  color: var(--c-muted);
}

.page-about .about-legend {
  display: grid;
  gap: .7rem;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .about-legend__item {
  display: grid;
  grid-template-columns: 10px minmax(0, 1fr) auto;
  align-items: center;
  gap: .6rem;
  font-size: .9rem;
}

.page-about .about-legend__dot {
  width: 10px;
  height: 10px;
  border-radius: 2px;
}

.page-about .about-legend__dot--a { background: var(--c-cyan); }
.page-about .about-legend__dot--b { background: var(--c-violet); }
.page-about .about-legend__dot--c { background: var(--c-mint); }
.page-about .about-legend__dot--d { background: var(--c-line); }

.page-about .about-legend__name {
  color: var(--c-ink);
}

.page-about .about-legend__val {
  font-family: var(--font-mono);
  font-size: .95rem;
  color: var(--c-glow);
}

.page-about .about-roles {
  display: grid;
  gap: 1px;
  margin: 0 0 clamp(1.75rem, 4vw, 2.5rem);
  padding: 1px;
  list-style: none;
  background: var(--c-line);
  border: 1px solid var(--c-line);
  border-radius: var(--r-md);
  overflow: hidden;
}

.page-about .about-role {
  background: var(--c-panel);
  padding: 1.15rem 1.15rem 1.25rem;
  transition: background var(--dur) var(--ease);
}

.page-about .about-role:hover,
.page-about .about-role:focus-within {
  background: var(--c-panel-hi);
}

.page-about .about-role__title {
  margin: 0 0 .5rem;
  font-size: 1rem;
  font-weight: 800;
  color: var(--c-ink);
}

.page-about .about-role__title::before {
  content: "";
  display: inline-block;
  width: 14px;
  height: 2px;
  margin-right: .55rem;
  vertical-align: middle;
  background: var(--c-cyan);
}

.page-about .about-role__text {
  margin: 0;
  font-size: .92rem;
}

/* ---------- 04 流程 ---------- */
.page-about .about-steps {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.5rem;
  margin: 0;
  padding: 0;
  list-style: none;
  counter-reset: none;
}

.page-about .about-step {
  position: relative;
  padding-top: 1.15rem;
  border-top: 2px solid var(--c-line);
}

.page-about .about-step::before {
  content: "";
  position: absolute;
  top: -2px;
  left: 0;
  width: 38px;
  height: 2px;
  background: var(--c-cyan);
}

.page-about .about-step:nth-child(3)::before,
.page-about .about-step:nth-child(4)::before {
  background: var(--c-violet);
}

.page-about .about-step:nth-child(5)::before {
  background: var(--c-mint);
}

.page-about .about-step__no {
  display: block;
  margin-bottom: .45rem;
  font-family: var(--font-mono);
  font-size: .72rem;
  letter-spacing: .16em;
  color: var(--c-glow);
}

.page-about .about-step__title {
  margin: 0 0 .45rem;
  font-size: 1rem;
  font-weight: 800;
  color: var(--c-ink);
}

.page-about .about-step__text {
  margin: 0;
  font-size: .9rem;
}

/* ---------- 05 栏目 ---------- */
.page-about .about-cols {
  display: grid;
  gap: 1rem;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .about-col {
  position: relative;
  padding: 1.3rem 1.2rem 1.4rem;
  background: var(--c-panel);
  border: 1px solid var(--c-line);
  border-radius: var(--r-md);
  clip-path: polygon(0 0, calc(100% - 18px) 0, 100% 18px, 100% 100%, 18px 100%, 0 calc(100% - 18px));
  transition: border-color var(--dur) var(--ease), transform var(--dur) var(--ease);
}

.page-about .about-col:hover {
  border-color: rgba(41, 240, 222, .5);
  transform: translateY(-2px);
}

.page-about .about-col__tag {
  display: inline-block;
  margin-bottom: .7rem;
  padding: .2rem .55rem;
  font-size: .68rem;
  letter-spacing: .12em;
  color: var(--c-cyan);
  border: 1px solid rgba(41, 240, 222, .32);
  border-radius: var(--r-sm);
}

.page-about .about-col__title {
  margin: 0 0 .5rem;
  font-size: 1rem;
  font-weight: 800;
  color: var(--c-ink);
}

.page-about .about-col__text {
  margin: 0 !important;
  font-size: .9rem;
}

.page-about .about-note-panel {
  margin-top: 1.5rem;
  padding: 1.1rem 1.2rem;
  border-left: 2px solid var(--c-violet);
  background: linear-gradient(90deg, rgba(138, 92, 255, .1), rgba(138, 92, 255, 0) 72%);
  border-radius: 0 var(--r-md) var(--r-md) 0;
}

.page-about .about-note-panel__text {
  margin: 0 !important;
  font-size: .92rem;
}

/* ---------- 06 合作 ---------- */
.page-about .about-partners {
  display: grid;
  gap: clamp(1.5rem, 4vw, 2.5rem);
  align-items: start;
}

.page-about .about-partners__body p:first-child {
  margin-top: 0;
}

.page-about .about-facts {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: 0;
  padding: 1px;
  list-style: none;
  background: var(--c-line);
  border: 1px solid var(--c-line);
  border-radius: var(--r-md);
  overflow: hidden;
}

.page-about .about-fact {
  display: flex;
  flex-direction: column;
  gap: .3rem;
  padding: 1.05rem 1rem;
  background: var(--c-panel);
}

.page-about .about-fact__num {
  font-family: var(--font-mono);
  font-size: 1.45rem;
  font-weight: 700;
  color: var(--c-glow);
}

.page-about .about-fact__label {
  font-size: .78rem;
  color: var(--c-muted);
  line-height: 1.5;
}

/* ---------- 收束区 ---------- */
.page-about .about-cta {
  margin-top: clamp(2.5rem, 6vw, 4rem);
  padding-block: clamp(2rem, 5vw, 3.25rem);
  border-top: 1px solid var(--c-line);
  background:
    radial-gradient(120% 140% at 12% 0%, rgba(41, 240, 222, .09), rgba(6, 10, 28, 0) 60%),
    var(--c-void);
}

.page-about .about-cta__title {
  margin: 0 0 1.5rem;
  font-size: clamp(1.25rem, 3.4vw, 1.75rem);
  font-weight: 900;
  letter-spacing: -.01em;
  color: var(--c-ink);
}

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

.page-about .about-cta__link {
  display: flex;
  flex-direction: column;
  gap: .4rem;
  padding: 1.15rem 1.2rem;
  text-decoration: none;
  background: var(--c-panel);
  border: 1px solid var(--c-line);
  border-radius: var(--r-md);
  transition: border-color var(--dur) var(--ease), background var(--dur) var(--ease);
}

.page-about .about-cta__link:hover {
  border-color: rgba(138, 92, 255, .6);
  background: var(--c-panel-hi);
}

.page-about .about-cta__link-title {
  font-size: 1.02rem;
  font-weight: 800;
  color: var(--c-cyan);
}

.page-about .about-cta__link-desc {
  font-size: .88rem;
  line-height: 1.65;
  color: var(--c-muted);
}

/* ---------- 动效 ---------- */
@keyframes about-spin {
  to { transform: rotate(360deg); }
}

@keyframes about-breathe {
  0%, 100% { opacity: .78; transform: scale(.96); }
  50% { opacity: 1; transform: scale(1.04); }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-orbit__ring--mid,
  .page-about .about-orbit__core {
    animation: none;
  }
  .page-about .about-col:hover {
    transform: none;
  }
}

/* ---------- 响应式 ---------- */
@media (min-width: 720px) {
  .page-about .about-steps {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 1.75rem 1.5rem;
  }

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

@media (min-width: 960px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, .95fr);
  }

  .page-about .about-split {
    grid-template-columns: minmax(0, 1.15fr) minmax(0, .85fr);
  }

  .page-about .about-team {
    grid-template-columns: minmax(0, 260px) minmax(0, 1fr);
  }

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

  .page-about .about-partners {
    grid-template-columns: minmax(0, 1.2fr) minmax(0, .8fr);
  }
}

@media (min-width: 1024px) {
  .page-about .about-layout {
    grid-template-columns: var(--about-rail) minmax(0, 1fr);
    gap: clamp(2rem, 5vw, 4rem);
  }

  .page-about .about-index {
    position: sticky;
    top: 104px;
    border: 0;
    background: none;
    padding: 0;
    overflow: visible;
  }

  .page-about .about-index__list {
    flex-direction: column;
    gap: 0;
    white-space: normal;
  }

  .page-about .about-index__link {
    display: flex;
    width: 100%;
    padding: .6rem 0 .6rem .85rem;
    border-bottom: 0;
    border-left: 1px solid var(--c-line);
    font-size: .86rem;
    line-height: 1.5;
  }

  .page-about .about-index__link:hover,
  .page-about .about-index__link.is-active {
    border-left-color: var(--c-cyan);
    border-bottom-color: transparent;
    color: var(--c-cyan);
  }

  .page-about .about-steps {
    grid-template-columns: repeat(5, minmax(0, 1fr));
    gap: 1.25rem;
  }

  .page-about .about-head {
    grid-template-columns: auto auto minmax(0, 1fr);
  }

  .page-about .about-head .section-note {
    grid-column: 3;
    justify-self: end;
    text-align: right;
  }
}