.page-about {
  --about-line-bone: rgba(17, 19, 18, 0.14);
  --about-block: clamp(52px, 7vw, 96px);
  --about-gap: clamp(22px, 3vw, 40px);
}

.page-about .about-block {
  padding-block: var(--about-block);
}

.page-about .about-block--bone {
  background: var(--bone);
  color: var(--char);
}

.page-about .about-block--ink {
  background: var(--char);
  color: var(--bone);
}

.page-about .about-kicker {
  font-family: var(--font-mono);
  font-size: var(--step-13);
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--clay);
  margin: 0 0 14px;
}

.page-about .about-block--ink .about-kicker {
  color: var(--cyan);
}

.page-about .about-title {
  font-family: var(--font-serif);
  font-weight: 700;
  font-size: clamp(25px, 3.6vw, 40px);
  line-height: 1.22;
  letter-spacing: -0.01em;
  margin: 0 0 16px;
}

.page-about .about-intro {
  font-size: var(--step-17);
  line-height: 1.85;
  color: var(--muted);
  max-width: 62ch;
  margin: 0;
}

.page-about .about-block--ink .about-intro {
  color: var(--muted-dark);
}

/* ---------- 面包屑 ---------- */

.page-about .crumbs {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: var(--step-13);
  font-family: var(--font-mono);
  letter-spacing: 0.04em;
  padding-top: 6px;
}

.page-about .crumbs__item {
  color: var(--muted-dark);
  text-decoration: none;
}

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

.page-about .crumbs__item.is-current {
  color: var(--bone);
}

.page-about .crumbs__sep {
  color: var(--muted);
}

/* ---------- 首屏 ---------- */

.page-about .about-hero {
  position: relative;
  overflow: hidden;
  padding-block: clamp(22px, 4vw, 40px) clamp(48px, 7vw, 88px);
  background:
    radial-gradient(120% 90% at 84% 4%, rgba(53, 240, 182, 0.12), transparent 56%),
    radial-gradient(90% 76% at 6% 96%, rgba(138, 92, 255, 0.14), transparent 62%),
    var(--ink);
  color: var(--bone);
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image: repeating-linear-gradient(90deg, rgba(243, 239, 230, 0.04) 0 1px, transparent 1px 86px);
}

.page-about .about-hero .shell {
  position: relative;
  z-index: 1;
}

.page-about .about-hero__inner {
  padding-top: clamp(28px, 5vw, 60px);
}

.page-about .about-hero__eyebrow {
  font-family: var(--font-mono);
  font-size: var(--step-13);
  letter-spacing: 0.24em;
  text-transform: uppercase;
  color: var(--cyan);
  margin: 0 0 20px;
}

.page-about .about-hero__title {
  font-family: var(--font-serif);
  font-weight: 700;
  font-size: clamp(32px, 6vw, 62px);
  line-height: 1.14;
  letter-spacing: -0.015em;
  margin: 0 0 24px;
  max-width: 17em;
}

.page-about .about-hero__lead {
  font-size: clamp(16px, 1.6vw, 19px);
  line-height: 1.9;
  color: rgba(243, 239, 230, 0.82);
  max-width: 58ch;
  margin: 0;
}

.page-about .about-hero__stats {
  list-style: none;
  margin: clamp(34px, 5vw, 60px) 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--line);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.page-about .about-stat {
  background: var(--ink);
  padding: 20px 16px 22px;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.page-about .about-stat__num {
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: clamp(28px, 4.6vw, 48px);
  line-height: 1;
  letter-spacing: -0.03em;
  color: var(--cyan);
  text-shadow: 0 0 22px rgba(53, 240, 182, 0.28);
}

.page-about .about-stat__unit {
  font-size: 0.44em;
  margin-left: 4px;
  color: rgba(53, 240, 182, 0.7);
  letter-spacing: 0;
}

.page-about .about-stat__label {
  font-size: var(--step-13);
  color: var(--muted-dark);
  letter-spacing: 0.04em;
}

/* ---------- 编年条 ---------- */

.page-about .about-chrono {
  background: var(--char);
  color: var(--bone);
}

.page-about .about-chrono__layout {
  display: grid;
  gap: clamp(30px, 4vw, 48px);
}

.page-about .about-chrono__tabs {
  margin-top: clamp(30px, 4vw, 46px);
}

.page-about .about-chrono__list {
  display: flex;
  align-items: flex-end;
  gap: 0;
  overflow-x: auto;
  padding-bottom: 10px;
  scrollbar-width: thin;
}

.page-about .about-node {
  position: relative;
  flex: 1 0 auto;
  min-width: 116px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 14px;
  padding: 20px 8px 18px;
  margin: 0;
  border: 0;
  background: none;
  color: var(--muted-dark);
  font: inherit;
  cursor: pointer;
  transition: color 0.22s var(--ease);
}

.page-about .about-node:not(:last-child)::before {
  content: "";
  position: absolute;
  top: 27px;
  left: 50%;
  right: -50%;
  height: 1px;
  background: var(--clay);
  opacity: 0.6;
}

.page-about .about-node__dot {
  position: relative;
  z-index: 1;
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--moss);
  border: 1px solid var(--clay);
  transition: background 0.22s var(--ease), box-shadow 0.22s var(--ease), transform 0.22s var(--ease);
}

.page-about .about-node:nth-child(1) .about-node__dot { width: 11px; height: 11px; }
.page-about .about-node:nth-child(2) .about-node__dot { width: 14px; height: 14px; }
.page-about .about-node:nth-child(3) .about-node__dot { width: 16px; height: 16px; }
.page-about .about-node:nth-child(4) .about-node__dot { width: 15px; height: 15px; }
.page-about .about-node:nth-child(5) .about-node__dot { width: 18px; height: 18px; }
.page-about .about-node:nth-child(6) .about-node__dot { width: 20px; height: 20px; }
.page-about .about-node:nth-child(7) .about-node__dot { width: 22px; height: 22px; }

.page-about .about-node__label {
  font-family: var(--font-mono);
  font-size: var(--step-13);
  letter-spacing: 0.04em;
  white-space: nowrap;
}

.page-about .about-node:hover .about-node__dot,
.page-about .about-node:focus-visible .about-node__dot {
  background: var(--clay);
}

.page-about .about-node:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 2px;
  border-radius: var(--radius-sm);
}

.page-about .about-node[aria-selected="true"] .about-node__dot {
  background: var(--cyan);
  border-color: var(--cyan);
  box-shadow: 0 0 0 7px rgba(53, 240, 182, 0.16);
}

.page-about .about-node[aria-selected="true"] .about-node__label {
  color: var(--bone);
}

.page-about .about-chrono__panels {
  display: grid;
  gap: 14px;
  margin-top: 6px;
}

.page-about .about-panel {
  background: var(--glass);
  border: 1px solid var(--line);
  border-left: 2px solid var(--clay);
  border-radius: var(--radius);
  padding: clamp(20px, 3vw, 30px);
}

.page-about .about-panel__title {
  font-family: var(--font-serif);
  font-size: var(--step-20);
  font-weight: 700;
  margin: 0 0 10px;
  color: var(--bone);
  letter-spacing: -0.005em;
}

.page-about .about-panel__text {
  font-size: var(--step-15);
  line-height: 1.85;
  color: var(--muted-dark);
  margin: 0 0 16px;
  max-width: 64ch;
}

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

.page-about .about-chrono__figure img {
  display: block;
  width: 100%;
  height: auto;
  border-radius: var(--radius);
  object-fit: cover;
  border: 1px solid var(--line);
}

.page-about .about-chrono__figure figcaption {
  margin-top: 12px;
  font-size: var(--step-13);
  line-height: 1.7;
  color: var(--muted);
  max-width: 34ch;
}

/* ---------- 一句话立场 ---------- */

.page-about .about-stance {
  padding-block: clamp(38px, 5vw, 68px);
  border-bottom: 1px solid var(--about-line-bone);
}

.page-about .about-stance__line {
  font-family: var(--font-serif);
  font-size: clamp(20px, 2.6vw, 30px);
  line-height: 1.62;
  letter-spacing: -0.005em;
  color: var(--char);
  max-width: 30ch;
  margin: 0 auto 0 0;
  padding-left: clamp(14px, 2vw, 26px);
  border-left: 3px solid var(--cyan);
}

/* ---------- 三道校验 ---------- */

.page-about .about-flow {
  padding-top: clamp(40px, 5vw, 72px);
}

.page-about .about-flow__figure {
  margin: clamp(30px, 4vw, 48px) 0 0;
}

.page-about .about-flow__figure img {
  display: block;
  width: 100%;
  height: auto;
  border-radius: var(--radius);
  object-fit: cover;
}

.page-about .about-flow__figure figcaption {
  margin-top: 12px;
  font-size: var(--step-13);
  color: var(--muted);
}

.page-about .about-flow__steps {
  list-style: none;
  margin: clamp(34px, 4vw, 56px) 0 0;
  padding: 0;
  display: grid;
  gap: 26px;
}

.page-about .about-step {
  position: relative;
  border-top: 2px solid var(--about-line-bone);
  padding-top: 20px;
}

.page-about .about-step::before {
  content: "";
  position: absolute;
  top: -2px;
  left: 0;
  width: 54px;
  height: 2px;
  background: var(--cyan);
}

.page-about .about-step:nth-child(2)::before { background: var(--clay); }
.page-about .about-step:nth-child(3)::before { background: var(--kapok); }

.page-about .about-step__no {
  display: block;
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: clamp(30px, 4vw, 46px);
  line-height: 1;
  letter-spacing: -0.03em;
  color: rgba(17, 19, 18, 0.14);
  margin-bottom: 12px;
}

.page-about .about-step__title {
  font-family: var(--font-serif);
  font-size: var(--step-20);
  font-weight: 700;
  margin: 0 0 10px;
}

.page-about .about-step__text {
  font-size: var(--step-15);
  line-height: 1.85;
  color: var(--muted);
  margin: 0 0 12px;
}

.page-about .about-step__time {
  font-family: var(--font-mono);
  font-size: var(--step-13);
  color: var(--clay);
  margin: 0;
  padding-top: 10px;
  border-top: 1px dashed var(--about-line-bone);
}

.page-about .about-flow__note {
  margin: clamp(30px, 4vw, 44px) 0 0;
  padding: 20px 22px;
  background: rgba(185, 107, 74, 0.08);
  border-left: 3px solid var(--clay);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  font-size: var(--step-15);
  line-height: 1.85;
  color: var(--muted);
  max-width: 74ch;
}

/* ---------- 团队 ---------- */

.page-about .about-team__grid {
  display: grid;
  gap: clamp(32px, 4vw, 52px);
}

.page-about .about-team__note {
  margin: 22px 0 0;
  font-size: var(--step-15);
  line-height: 1.85;
  color: var(--muted-dark);
  max-width: 52ch;
}

.page-about .about-chart__title {
  font-family: var(--font-mono);
  font-size: var(--step-13);
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--muted);
  margin: 0 0 22px;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--line);
}

.page-about .about-roles {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 24px;
}

.page-about .about-role {
  display: grid;
  gap: 8px;
}

.page-about .about-role__name {
  font-family: var(--font-mono);
  font-size: var(--step-15);
  color: var(--bone);
  letter-spacing: 0.02em;
}

.page-about .about-role__bar {
  display: block;
  width: var(--w, 20%);
  min-width: 42px;
  height: 12px;
  border-radius: 999px;
  background: linear-gradient(90deg, rgba(53, 240, 182, 0.9), rgba(53, 240, 182, 0.35));
  transition: filter 0.22s var(--ease);
}

.page-about .about-role:nth-child(2) .about-role__bar {
  background: linear-gradient(90deg, rgba(185, 107, 74, 0.95), rgba(185, 107, 74, 0.35));
}

.page-about .about-role:nth-child(3) .about-role__bar {
  background: linear-gradient(90deg, rgba(232, 179, 61, 0.95), rgba(232, 179, 61, 0.3));
}

.page-about .about-role:hover .about-role__bar,
.page-about .about-role:focus-within .about-role__bar {
  filter: brightness(1.18);
}

.page-about .about-role__duty {
  font-size: var(--step-13);
  line-height: 1.78;
  color: var(--muted-dark);
  max-width: 46ch;
}

.page-about .about-team__link {
  margin: 30px 0 0;
  padding-top: 20px;
  border-top: 1px solid var(--line);
  font-size: var(--step-15);
  line-height: 1.8;
  color: var(--muted-dark);
}

.page-about .about-team__link a {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(53, 240, 182, 0.4);
}

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

/* ---------- 四条内容线 ---------- */

.page-about .about-lines__list {
  margin-top: clamp(30px, 4vw, 48px);
  border-top: 1px solid var(--about-line-bone);
}

.page-about .about-line {
  display: grid;
  gap: 8px;
  padding: 24px 0;
  border-bottom: 1px solid var(--about-line-bone);
}

.page-about .about-line__no {
  font-family: var(--font-mono);
  font-size: var(--step-13);
  letter-spacing: 0.14em;
  color: var(--clay);
}

.page-about .about-line__title {
  font-family: var(--font-serif);
  font-size: var(--step-20);
  font-weight: 700;
  margin: 0 0 8px;
}

.page-about .about-line__text {
  margin: 0;
  font-size: var(--step-15);
  line-height: 1.85;
  color: var(--muted);
  max-width: 62ch;
}

.page-about .about-line__who {
  margin: 0;
  font-size: var(--step-13);
  line-height: 1.7;
  color: var(--clay);
}

/* ---------- 协作生态 ---------- */

.page-about .about-network {
  background:
    radial-gradient(80% 60% at 20% 12%, rgba(226, 84, 42, 0.1), transparent 60%),
    radial-gradient(70% 60% at 88% 78%, rgba(138, 92, 255, 0.12), transparent 62%),
    var(--char);
  color: var(--bone);
}

.page-about .about-network__grid {
  display: grid;
  gap: clamp(30px, 4vw, 46px);
  margin-top: clamp(30px, 4vw, 48px);
}

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

.page-about .about-net__link {
  stroke: var(--rock);
  stroke-width: 1;
  stroke-dasharray: 4 6;
  opacity: 0.65;
}

.page-about .about-net__node {
  fill: var(--moss);
  stroke: var(--rock);
  stroke-width: 1;
}

.page-about .about-net__node--v { fill: rgba(138, 92, 255, 0.7); stroke: var(--violet); }
.page-about .about-net__node--k { fill: rgba(226, 84, 42, 0.7); stroke: var(--kapok); }
.page-about .about-net__node--c { fill: rgba(53, 240, 182, 0.55); stroke: var(--cyan); }

.page-about .about-net__hub {
  fill: var(--ink);
  stroke: var(--cyan);
  stroke-width: 2;
}

.page-about .about-net__hub-ring {
  fill: none;
  stroke: var(--cyan);
  stroke-width: 1;
  stroke-dasharray: 3 7;
  opacity: 0.5;
}

.page-about .about-network__text {
  margin: 20px 0 0;
  font-size: var(--step-15);
  line-height: 1.85;
  color: var(--muted-dark);
  max-width: 48ch;
}

.page-about .about-network__facts {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 18px;
  margin: 30px 0 0;
  padding-top: 22px;
  border-top: 1px solid var(--line);
}

.page-about .about-fact dt {
  font-size: var(--step-13);
  color: var(--muted);
  letter-spacing: 0.04em;
  margin-bottom: 8px;
}

.page-about .about-fact dd {
  margin: 0;
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: clamp(26px, 3.4vw, 38px);
  line-height: 1;
  color: var(--cyan);
  letter-spacing: -0.02em;
}

.page-about .about-network__banner {
  margin: clamp(36px, 5vw, 60px) 0 0;
}

.page-about .about-network__banner img {
  display: block;
  width: 100%;
  height: auto;
  border-radius: var(--radius);
  object-fit: cover;
  border: 1px solid var(--line);
}

.page-about .about-network__banner figcaption {
  margin-top: 12px;
  font-size: var(--step-13);
  color: var(--muted);
}

/* ---------- 版本演进 ---------- */

.page-about .about-versions__grid {
  display: grid;
  gap: clamp(32px, 4vw, 52px);
}

.page-about .about-versions__list {
  list-style: none;
  margin: 0;
  padding: 0 0 0 26px;
  border-left: 1px solid var(--about-line-bone);
  display: grid;
  gap: 34px;
}

.page-about .about-ver {
  position: relative;
}

.page-about .about-ver::before {
  content: "";
  position: absolute;
  left: -31px;
  top: 7px;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--bone);
  border: 2px solid var(--clay);
}

.page-about .about-ver--now::before {
  background: var(--cyan);
  border-color: var(--cyan);
  box-shadow: 0 0 0 5px rgba(53, 240, 182, 0.22);
}

.page-about .about-ver__tag {
  font-family: var(--font-mono);
  font-size: var(--step-13);
  letter-spacing: 0.12em;
  color: var(--clay);
  display: block;
  margin-bottom: 6px;
}

.page-about .about-ver--now .about-ver__tag {
  color: var(--ink);
}

.page-about .about-ver__title {
  font-family: var(--font-serif);
  font-size: var(--step-20);
  font-weight: 700;
  margin: 0 0 8px;
}

.page-about .about-ver__text {
  margin: 0;
  font-size: var(--step-15);
  line-height: 1.85;
  color: var(--muted);
  max-width: 60ch;
}

/* ---------- 结尾导流 ---------- */

.page-about .about-next__inner {
  display: grid;
  gap: 20px;
  justify-items: start;
}

.page-about .about-next__title {
  font-family: var(--font-serif);
  font-size: clamp(26px, 3.6vw, 40px);
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: -0.01em;
  margin: 0;
}

.page-about .about-next__text {
  margin: 0;
  font-size: var(--step-17);
  line-height: 1.85;
  color: var(--muted-dark);
  max-width: 58ch;
}

.page-about .about-next__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  margin-top: 10px;
}

/* ---------- 响应式 ---------- */

@media (min-width: 700px) {
  .page-about .about-hero__stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .about-stat {
    padding: 26px 22px 28px;
  }

  .page-about .about-line {
    grid-template-columns: 54px minmax(0, 1fr) 210px;
    align-items: start;
    gap: 28px;
  }

  .page-about .about-line__who {
    text-align: right;
    padding-top: 6px;
  }
}

@media (min-width: 900px) {
  .page-about .about-chrono__layout {
    grid-template-columns: minmax(0, 1fr) 300px;
    align-items: start;
  }

  .page-about .about-chrono__list {
    overflow-x: visible;
  }

  .page-about .about-flow__steps {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 30px;
  }

  .page-about .about-team__grid {
    grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
    align-items: start;
  }

  .page-about .about-network__grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    align-items: center;
  }

  .page-about .about-versions__grid {
    grid-template-columns: minmax(0, 4fr) minmax(0, 7fr);
    align-items: start;
  }
}

@media (min-width: 1100px) {
  .page-about .about-chrono__layout {
    grid-template-columns: minmax(0, 1fr) 340px;
    gap: 64px;
  }

  .page-about .about-roles {
    gap: 30px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about *,
  .page-about *::before,
  .page-about *::after {
    transition-duration: 0.001ms !important;
    animation-duration: 0.001ms !important;
  }
}

.page-about {
  --w: 1rem;
}