.page-about {
  --about-narrow: 34rem;
  --about-gap: clamp(28px, 5vw, 64px);
  padding-bottom: clamp(48px, 8vw, 96px);
}

/* ---------- 页面头部 ---------- */
.page-about .about-hero {
  padding: clamp(18px, 3.5vw, 34px) 0 clamp(34px, 6vw, 70px);
  border-bottom: var(--line);
}

.page-about .about-hero__inner {
  max-width: var(--about-narrow);
  margin-top: clamp(26px, 5vw, 54px);
}

.page-about .about-hero__inner .display-1 {
  margin: 14px 0 0;
  line-height: 1.05;
  letter-spacing: -0.02em;
  text-wrap: balance;
}

.page-about .about-hero__inner .lede {
  margin: clamp(18px, 3vw, 26px) 0 0;
}

.page-about .about-hero__inner .note {
  margin: 16px 0 0;
  padding-left: 14px;
  border-left: 3px solid var(--frame);
}

/* ---------- 使命窄栏 ---------- */
.page-about .about-mission {
  padding: clamp(44px, 7vw, 92px) 0;
}

.page-about .about-mission__grid {
  display: grid;
  gap: var(--about-gap);
  align-items: start;
}

.page-about .about-mission__copy .display-2 {
  margin: 14px 0 0;
}

.page-about .about-mission__lead {
  margin: clamp(18px, 3vw, 28px) 0 0;
  padding-left: 18px;
  border-left: 4px solid var(--cyan);
  font-family: var(--font-display);
  font-size: clamp(1.25rem, 3.4vw, 1.85rem);
  line-height: 1.42;
  letter-spacing: -0.01em;
  color: var(--ink);
}

.page-about .about-mission__body {
  margin: 22px 0 0;
  color: var(--ink-2);
  line-height: 1.78;
}

.page-about .about-mission__links {
  margin: 18px 0 0;
  font-size: 0.94rem;
  color: var(--ink-2);
}

.page-about .about-mission__links a {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(111, 242, 216, 0.45);
  padding-bottom: 1px;
}

.page-about .about-mission__links a:hover,
.page-about .about-mission__links a:focus-visible {
  border-bottom-color: var(--cyan);
  border-bottom-width: 2px;
}

.page-about .about-mission__media {
  margin: 0;
}

/* ---------- 覆盖范围 ---------- */
.page-about .about-scope {
  padding: clamp(44px, 7vw, 92px) 0;
  border-top: var(--line);
}

.page-about .about-scope__head {
  max-width: 52rem;
}

.page-about .about-scope__head .lede {
  margin-top: clamp(14px, 2.4vw, 22px);
}

.page-about .about-scope__media {
  margin: clamp(26px, 4.5vw, 48px) 0 0;
}

.page-about .about-scope__grid {
  display: grid;
  gap: var(--about-gap);
  margin-top: clamp(28px, 5vw, 56px);
  align-items: start;
}

.page-about .about-ring {
  position: relative;
  width: min(240px, 62vw);
  aspect-ratio: 1;
  margin-inline: auto;
}

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

.page-about .about-ring__svg circle {
  fill: none;
  stroke-width: 22;
}

.page-about .about-ring__svg circle:nth-of-type(1) { stroke: var(--cyan); }
.page-about .about-ring__svg circle:nth-of-type(2) { stroke: var(--orange); }
.page-about .about-ring__svg circle:nth-of-type(3) { stroke: var(--mist); }
.page-about .about-ring__svg circle:nth-of-type(4) { stroke: var(--clay); }

.page-about .about-ring__core {
  position: absolute;
  inset: 0;
  margin: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  pointer-events: none;
}

.page-about .about-ring__core .data {
  font-size: clamp(2.4rem, 9vw, 3.4rem);
  font-weight: 700;
  line-height: 1;
  color: var(--ink);
  font-variant-numeric: tabular-nums;
}

.page-about .about-ring__unit {
  margin-top: 8px;
  font-size: 11px;
  letter-spacing: 0.18em;
  color: var(--ink-2);
}

.page-about .about-cats {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 14px;
}

.page-about .about-cat {
  border: var(--line);
  border-left-width: 5px;
  background: var(--panel);
  padding: 16px 18px;
  box-shadow: var(--shadow-soft);
}

.page-about .about-cat:nth-child(1) { border-left-color: var(--cyan); }
.page-about .about-cat:nth-child(2) { border-left-color: var(--orange); }
.page-about .about-cat:nth-child(3) { border-left-color: var(--mist); }
.page-about .about-cat:nth-child(4) { border-left-color: var(--clay); }

.page-about .about-cat__name {
  margin: 0;
  font-family: var(--font-display);
  font-size: 1.05rem;
  font-weight: 700;
  letter-spacing: -0.01em;
  color: var(--ink);
}

.page-about .about-cat__meta {
  margin: 8px 0 0;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  color: var(--ink-2);
}

.page-about .about-cat__meta .data {
  color: var(--orange);
  font-size: 13px;
  letter-spacing: 0;
}

.page-about .about-cat__desc {
  margin: 10px 0 0;
  font-size: 0.92rem;
  line-height: 1.7;
  color: var(--ink-2);
}

.page-about .about-scope__note {
  margin: clamp(26px, 4vw, 40px) 0 0;
  padding-top: 16px;
  border-top: 1px dashed var(--frame);
  font-size: 0.9rem;
  line-height: 1.75;
  color: var(--ink-2);
}

.page-about .about-scope__note a {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(111, 242, 216, 0.45);
}

/* ---------- 编校原则 ---------- */
.page-about .about-rules {
  padding: clamp(44px, 7vw, 92px) 0;
  border-top: var(--line);
}

.page-about .about-rules__grid {
  display: grid;
  gap: var(--about-gap);
  margin-top: clamp(26px, 4vw, 44px);
  align-items: start;
}

.page-about .about-rules__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 16px;
  counter-reset: about-rule;
}

.page-about .about-rule {
  border: var(--line);
  border-left-width: 6px;
  background: linear-gradient(180deg, rgba(46, 95, 85, 0.24), rgba(18, 48, 42, 0.72));
  padding: clamp(18px, 3vw, 26px);
  box-shadow: var(--shadow-soft);
  transition: border-color 0.22s var(--ease), box-shadow 0.22s var(--ease), transform 0.22s var(--ease);
}

.page-about .about-rule:hover,
.page-about .about-rule:focus-within {
  border-color: var(--cyan);
  box-shadow: var(--shadow-cyan);
  transform: translate(-2px, -2px);
}

.page-about .about-rule__idx {
  margin: 0;
  font-size: 0.84rem;
  letter-spacing: 0.18em;
  color: var(--cyan);
}

.page-about .about-rule__name {
  margin: 10px 0 0;
  font-family: var(--font-display);
  font-size: clamp(1.05rem, 2.4vw, 1.25rem);
  font-weight: 700;
  letter-spacing: -0.01em;
  color: var(--ink);
}

.page-about .about-rule__desc {
  margin: 12px 0 0;
  font-size: 0.93rem;
  line-height: 1.78;
  color: var(--ink-2);
}

.page-about .about-rules__texture {
  margin: 0;
}

/* ---------- 团队 ---------- */
.page-about .about-team {
  padding: clamp(44px, 7vw, 92px) 0;
  border-top: var(--line);
}

.page-about .about-team__grid {
  list-style: none;
  margin: clamp(24px, 4vw, 40px) 0 0;
  padding: 0;
  display: grid;
  gap: 12px;
}

.page-about .about-team__row {
  display: grid;
  grid-template-columns: minmax(5rem, auto) minmax(0, 1fr) 1.8rem;
  align-items: center;
  gap: 14px;
  padding: 12px 14px;
  border: var(--line);
  background: var(--panel);
}

.page-about .about-team__k {
  font-family: var(--font-display);
  font-size: 0.94rem;
  font-weight: 700;
  color: var(--ink);
  white-space: nowrap;
}

.page-about .about-team__track {
  display: block;
  height: 14px;
  background: rgba(46, 95, 85, 0.42);
  border: 1px solid var(--frame);
  overflow: hidden;
}

.page-about .about-team__bar {
  display: block;
  height: 100%;
  background: linear-gradient(90deg, var(--cyan), var(--mist));
}

.page-about .about-team__bar--a { width: 41.7%; }
.page-about .about-team__bar--b { width: 25%; }
.page-about .about-team__bar--c { width: 16.7%; }
.page-about .about-team__bar--d { width: 16.7%; }

.page-about .about-team__v {
  text-align: right;
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--orange);
}

.page-about .about-team__notes {
  margin-top: clamp(20px, 3vw, 30px);
  display: grid;
  gap: 14px;
  max-width: 46rem;
}

.page-about .about-team__notes p {
  margin: 0;
  padding-left: 14px;
  border-left: 3px solid var(--frame);
  font-size: 0.92rem;
  line-height: 1.78;
  color: var(--ink-2);
}

/* ---------- 演进阶段 ---------- */
.page-about .about-stages {
  padding: clamp(44px, 7vw, 92px) 0;
  border-top: var(--line);
}

.page-about .about-stages__list {
  display: grid;
  gap: 14px;
  margin-top: clamp(26px, 4vw, 44px);
}

.page-about .about-stage {
  border: var(--line);
  background: var(--panel);
  box-shadow: var(--shadow-soft);
  transition: border-color 0.22s var(--ease), box-shadow 0.22s var(--ease);
}

.page-about .about-stage:hover,
.page-about .about-stage:focus-within {
  border-color: rgba(111, 242, 216, 0.55);
  box-shadow: var(--shadow-cyan);
}

.page-about .about-stage__head {
  margin: 0;
  font-size: inherit;
  font-weight: inherit;
}

.page-about .about-stage__trigger {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr) auto auto;
  align-items: center;
  gap: 12px;
  width: 100%;
  padding: 16px 18px;
  background: transparent;
  border: 0;
  color: inherit;
  font: inherit;
  text-align: left;
  cursor: pointer;
}

.page-about .about-stage__idx {
  font-size: 0.82rem;
  letter-spacing: 0.16em;
  color: var(--orange);
}

.page-about .about-stage__name {
  font-family: var(--font-display);
  font-size: clamp(1rem, 2.4vw, 1.15rem);
  font-weight: 700;
  letter-spacing: -0.01em;
  color: var(--ink);
}

.page-about .about-stage__hint {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  color: var(--ink-2);
  white-space: nowrap;
}

.page-about .about-stage__panel {
  padding: 14px 18px 18px;
  border-top: 1px dashed var(--frame);
  font-size: 0.93rem;
  line-height: 1.78;
  color: var(--ink-2);
}

.page-about .about-stage__panel p {
  margin: 0;
  max-width: 52rem;
}

/* ---------- 边界 ---------- */
.page-about .about-limits {
  padding: clamp(44px, 7vw, 92px) 0 0;
}

.page-about .about-limits__panel {
  border: var(--line);
  border-top: 6px solid var(--clay);
  background: linear-gradient(135deg, rgba(180, 87, 58, 0.18), rgba(18, 48, 42, 0.88) 58%);
  padding: clamp(22px, 4vw, 42px);
  box-shadow: var(--shadow-soft);
}

.page-about .about-limits__panel .display-3 {
  margin: 12px 0 0;
}

.page-about .about-limits__list {
  list-style: none;
  margin: clamp(20px, 3vw, 34px) 0 0;
  padding: 0;
  display: grid;
  gap: 16px;
}

.page-about .about-limits__list li {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 12px;
  align-items: start;
  padding-top: 14px;
  border-top: 1px solid var(--frame);
}

.page-about .about-limits__no {
  font-size: 0.82rem;
  letter-spacing: 0.16em;
  color: var(--clay);
  padding-top: 2px;
}

.page-about .about-limits__list p {
  margin: 0;
  font-size: 0.95rem;
  line-height: 1.72;
  color: var(--ink);
}

.page-about .about-limits__foot {
  margin: clamp(24px, 3.4vw, 34px) 0 0;
  padding-top: 16px;
  border-top: 1px dashed var(--frame);
  font-size: 0.9rem;
  line-height: 1.75;
  color: var(--ink-2);
}

.page-about .about-limits__foot a {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(111, 242, 216, 0.45);
}

/* ---------- 响应式 ---------- */
@media (min-width: 720px) {
  .page-about .about-limits__list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 18px 30px;
  }
}

@media (min-width: 880px) {
  .page-about .about-mission__grid {
    grid-template-columns: minmax(0, 1.02fr) minmax(0, 1fr);
  }

  .page-about .about-mission__copy {
    max-width: var(--about-narrow);
  }

  .page-about .about-mission__media {
    margin-top: 10px;
  }

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

  .page-about .about-ring {
    width: 100%;
    max-width: 250px;
    margin-inline: 0;
    position: sticky;
    top: calc(var(--topbar-h) + 24px);
  }
}

@media (min-width: 960px) {
  .page-about .about-rules__grid {
    grid-template-columns: minmax(0, 1fr) minmax(0, 320px);
  }

  .page-about .about-stages__list {
    gap: 18px;
  }

  .page-about .about-stage:nth-child(1) { margin-left: 0; }
  .page-about .about-stage:nth-child(2) { margin-left: 6%; }
  .page-about .about-stage:nth-child(3) { margin-left: 12%; }
  .page-about .about-stage:nth-child(4) { margin-left: 18%; }
}

@media (max-width: 519px) {
  .page-about .about-team__row {
    grid-template-columns: minmax(0, 1fr) 1.6rem;
    grid-template-areas:
      "key val"
      "track track";
    row-gap: 10px;
  }

  .page-about .about-team__k { grid-area: key; }
  .page-about .about-team__v { grid-area: val; }
  .page-about .about-team__track { grid-area: track; }

  .page-about .about-stage__trigger {
    grid-template-columns: auto minmax(0, 1fr) auto;
    row-gap: 6px;
  }

  .page-about .about-stage__hint {
    grid-column: 2 / 3;
    grid-row: 2 / 3;
  }

  .page-about .about-stage__trigger .accordion__icon {
    grid-column: 3 / 4;
    grid-row: 1 / 3;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-rule,
  .page-about .about-stage {
    transition: none;
  }

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