.page-about {
  background: var(--ink);
  color: var(--silver);
  font-family: var(--font-sans);
}

.page-about h2 {
  font-size: clamp(22px, 3.6vw, 32px);
  line-height: 1.28;
  font-weight: 800;
  letter-spacing: -0.005em;
  color: var(--paper);
  margin: 0 0 16px;
}

.page-about h3 {
  font-size: clamp(18px, 2.4vw, 20px);
  font-weight: 800;
  color: var(--paper);
  margin: 0 0 10px;
}

.page-about p {
  font-size: 16px;
  line-height: 1.8;
  margin: 0 0 14px;
}

.page-about a:focus-visible,
.page-about summary:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 2px;
}

.page-about .about-link {
  color: var(--electric);
  text-decoration: none;
  background-image: linear-gradient(var(--cyan), var(--cyan));
  background-repeat: no-repeat;
  background-size: 0% 1px;
  background-position: 0 100%;
  transition: background-size 180ms var(--ease), color 180ms var(--ease);
}

.page-about .about-link:hover {
  color: var(--cyan);
  background-size: 100% 1px;
}

/* ---------- 首屏 ---------- */

.page-about .about-intro {
  position: relative;
  overflow: hidden;
  padding: clamp(20px, 4vw, 36px) 0 clamp(40px, 7vw, 76px);
  border-bottom: 1px solid var(--line-soft);
}

.page-about .about-intro::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background: linear-gradient(
    115deg,
    transparent 54%,
    rgba(46, 123, 255, 0.07) 54%,
    rgba(46, 123, 255, 0.07) 63%,
    transparent 63%
  );
}

.page-about .about-intro .container {
  position: relative;
  z-index: 1;
}

.page-about .about-intro .breadcrumb {
  margin-bottom: clamp(20px, 4vw, 36px);
}

.page-about .about-intro__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(26px, 4vw, 48px);
  align-items: start;
}

.page-about .about-intro h1 {
  font-size: clamp(30px, 6.4vw, 54px);
  line-height: 1.12;
  font-weight: 900;
  letter-spacing: -0.01em;
  color: var(--paper);
  margin: 10px 0 18px;
  transform: skewX(-3deg);
  transform-origin: left bottom;
}

.page-about .about-intro .lede {
  max-width: 60ch;
  font-size: clamp(16px, 1.6vw, 18px);
  line-height: 1.8;
  color: var(--silver);
  margin: 0;
}

.page-about .about-intro__panel {
  border: 1px solid var(--line);
  background:
    linear-gradient(180deg, rgba(46, 123, 255, 0.07), transparent 62%),
    var(--ink-2);
  box-shadow: var(--shadow-panel);
}

.page-about .about-intro__row {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 14px;
  padding: 12px 18px;
  border-bottom: 1px solid var(--line-soft);
  font-size: 14px;
}

.page-about .about-intro__row:last-child {
  border-bottom: 0;
}

.page-about .about-intro__k {
  color: var(--stone);
  letter-spacing: 0.04em;
}

.page-about .about-intro__v {
  font-family: var(--font-mono);
  font-size: 15px;
  letter-spacing: 0.06em;
  color: var(--cyan);
}

/* ---------- 为什么会有这个站 ---------- */

.page-about .about-why {
  padding: clamp(48px, 8vw, 92px) 0;
}

.page-about .about-why__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(28px, 4vw, 52px);
  align-items: start;
}

.page-about .about-why__copy p {
  max-width: 62ch;
}

.page-about .about-why__list {
  list-style: none;
  margin: 0;
  padding: 0;
  border-top: 1px solid var(--line);
}

.page-about .about-why__item {
  border-bottom: 1px solid var(--line);
  padding: 16px 0 18px;
  transition: padding-left 180ms var(--ease), background 180ms var(--ease);
}

.page-about .about-why__item:hover {
  padding-left: 10px;
  background: rgba(46, 123, 255, 0.06);
}

.page-about .about-why__label {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--electric);
  margin: 0 0 6px;
  transition: color 180ms var(--ease);
}

.page-about .about-why__item:hover .about-why__label {
  color: var(--cyan);
}

.page-about .about-why__desc {
  margin: 0;
  font-size: 15px;
  line-height: 1.75;
  color: var(--silver);
}

/* ---------- 版本沿革 ---------- */

.page-about .about-history {
  padding: clamp(48px, 8vw, 92px) 0;
  background: var(--ink-2);
  border-top: 1px solid var(--line-soft);
  border-bottom: 1px solid var(--line-soft);
}

.page-about .about-head {
  max-width: 720px;
  margin-bottom: clamp(24px, 4vw, 40px);
}

.page-about .about-head__sub {
  margin: 0;
  font-size: 16px;
  line-height: 1.8;
  color: var(--silver);
}

.page-about .about-head .eyebrow {
  margin-bottom: 10px;
}

.page-about .about-history__fig {
  margin: 0 0 clamp(28px, 5vw, 48px);
  border: 1px solid var(--line);
  background: var(--ink);
  overflow: hidden;
}

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

.page-about .about-history__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(28px, 4vw, 48px);
  align-items: start;
}

.page-about .about-tl {
  list-style: none;
  margin: 0;
  padding: 0;
  position: relative;
}

.page-about .about-tl::before {
  content: "";
  position: absolute;
  left: 5px;
  top: 10px;
  bottom: 10px;
  width: 1px;
  background: linear-gradient(180deg, var(--cyan), var(--line) 42%, var(--line));
  opacity: 0.55;
}

.page-about .about-tl__item {
  position: relative;
  padding: 0 0 clamp(26px, 4vw, 38px) 30px;
}

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

.page-about .about-tl__node {
  position: absolute;
  left: 0;
  top: 9px;
  width: 11px;
  height: 11px;
  border: 1px solid var(--cyan);
  border-radius: 50%;
  background: var(--ink-2);
  transition: background 180ms var(--ease), box-shadow 180ms var(--ease);
}

.page-about .about-tl__item--live .about-tl__node {
  background: var(--cyan);
  box-shadow: 0 0 0 5px rgba(78, 240, 224, 0.14);
}

.page-about .about-tl__item:hover .about-tl__node,
.page-about .about-tl__item:target .about-tl__node {
  background: var(--cyan);
  box-shadow: 0 0 0 5px rgba(78, 240, 224, 0.2);
}

.page-about .about-tl__body {
  border: 1px solid var(--line);
  background: var(--ink-3);
  padding: 16px 18px;
  transition: border-color 180ms var(--ease), transform 180ms var(--ease);
}

.page-about .about-tl__body:hover {
  border-color: var(--electric);
}

.page-about .about-tl__item:target .about-tl__body {
  border-color: var(--cyan);
  transform: translateY(-2px);
}

.page-about .about-tl__ver {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.18em;
  color: var(--cyan);
  margin: 0 0 6px;
}

.page-about .about-tl__body h3 {
  font-size: 19px;
  margin: 0 0 8px;
}

.page-about .about-tl__body p {
  margin: 0;
  font-size: 15px;
  line-height: 1.78;
  color: var(--silver);
}

.page-about .about-tl__tag {
  margin: 14px 0 0;
}

.page-about .about-gauge {
  border: 1px solid var(--line);
  background: var(--ink);
  padding: 18px;
}

.page-about .about-gauge__title {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--stone);
  margin: 0 0 6px;
}

.page-about .about-gauge__row {
  display: block;
  padding: 13px 0;
  border-top: 1px solid var(--line-soft);
  text-decoration: none;
  color: inherit;
  transition: background 180ms var(--ease), padding-left 180ms var(--ease);
}

.page-about .about-gauge__row:hover {
  background: rgba(46, 123, 255, 0.08);
  padding-left: 10px;
}

.page-about .about-gauge__ver {
  display: block;
  font-family: var(--font-mono);
  font-size: 15px;
  font-weight: 700;
  letter-spacing: 0.06em;
  color: var(--electric);
}

.page-about .about-gauge__desc {
  display: block;
  margin-top: 4px;
  font-size: 13.5px;
  line-height: 1.6;
  color: var(--silver);
}

.page-about .about-gauge__state {
  display: inline-block;
  margin-top: 9px;
  padding: 2px 8px;
  border: 1px solid var(--line);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.1em;
}

.page-about .about-gauge__state--done {
  color: var(--stone);
  border-color: var(--line);
}

.page-about .about-gauge__state--live {
  color: var(--ink);
  background: var(--cyan);
  border-color: var(--cyan);
}

/* ---------- 米白反转区：团队与流程 ---------- */

.page-about .about-paper {
  background: var(--paper);
  color: var(--ink-2);
  padding: clamp(48px, 8vw, 92px) 0;
}

.page-about .about-paper h2,
.page-about .about-paper h3,
.page-about .about-paper h4 {
  color: var(--ink-2);
}

.page-about .about-paper .eyebrow {
  color: var(--clay);
}

.page-about .about-paper .about-head__sub {
  color: #46536b;
}

.page-about .about-flow {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(26px, 4vw, 44px);
  align-items: start;
  margin-bottom: clamp(36px, 6vw, 60px);
}

.page-about .about-flow__text > p {
  color: #3f4c63;
  font-size: 15.5px;
  line-height: 1.78;
  max-width: 46ch;
}

.page-about .about-flow__steps {
  list-style: none;
  margin: 20px 0 0;
  padding: 0;
}

.page-about .about-flow__step {
  display: grid;
  grid-template-columns: 40px minmax(0, 1fr);
  gap: 16px;
  position: relative;
  padding-bottom: 22px;
}

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

.page-about .about-flow__step::before {
  content: "";
  position: absolute;
  left: 19px;
  top: 40px;
  bottom: 6px;
  width: 1px;
  background: rgba(11, 27, 58, 0.28);
  transform: skewX(-6deg);
}

.page-about .about-flow__step:last-child::before {
  display: none;
}

.page-about .about-flow__num {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 38px;
  height: 38px;
  position: relative;
  z-index: 1;
  background: var(--ink-2);
  color: var(--paper);
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.06em;
}

.page-about .about-flow__step h4 {
  margin: 5px 0 6px;
  font-size: 17px;
  font-weight: 800;
}

.page-about .about-flow__step p {
  margin: 0;
  font-size: 15px;
  line-height: 1.76;
  color: #3f4c63;
}

.page-about .about-flow__fig {
  margin: 0;
  border: 1px solid rgba(11, 27, 58, 0.2);
  overflow: hidden;
}

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

.page-about .about-team {
  border-top: 1px solid rgba(11, 27, 58, 0.2);
  padding-top: clamp(24px, 4vw, 36px);
}

.page-about .about-team h3 {
  margin: 0 0 20px;
  font-size: 20px;
}

.page-about .about-team__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: 1fr;
  gap: 22px;
}

.page-about .about-team__list li {
  border-left: 2px solid var(--ink-2);
  padding-left: 16px;
}

.page-about .about-team__num {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(30px, 5vw, 42px);
  font-weight: 700;
  line-height: 1;
  color: var(--ink-2);
  letter-spacing: -0.02em;
}

.page-about .about-team__role {
  margin: 10px 0 6px;
  font-size: 16px;
  font-weight: 800;
  color: var(--ink-2);
  line-height: 1.4;
}

.page-about .about-team__list li p:last-child {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.72;
  color: #3f4c63;
}

/* ---------- 栏目与专题 ---------- */

.page-about .about-catalog {
  padding: clamp(48px, 8vw, 92px) 0;
}

.page-about .about-catalog__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(26px, 4vw, 48px);
  align-items: start;
}

.page-about .about-tree {
  display: grid;
  gap: 12px;
}

.page-about .about-tree__node {
  border: 1px solid var(--line);
  background: var(--ink-2);
}

.page-about .about-tree summary {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  list-style: none;
  cursor: pointer;
  padding: 15px 18px;
  font-size: 16px;
  font-weight: 700;
  color: var(--paper);
  transition: background 180ms var(--ease), color 180ms var(--ease);
}

.page-about .about-tree summary::-webkit-details-marker {
  display: none;
}

.page-about .about-tree summary::after {
  content: "+";
  font-family: var(--font-mono);
  font-size: 17px;
  line-height: 1;
  color: var(--electric);
}

.page-about .about-tree__node[open] summary::after {
  content: "\2212";
  color: var(--cyan);
}

.page-about .about-tree summary:hover {
  background: rgba(46, 123, 255, 0.09);
}

.page-about .about-tree__lead {
  margin: 0;
  padding: 0 18px 12px;
  font-size: 14.5px;
  line-height: 1.72;
  color: var(--silver);
}

.page-about .about-tree__list {
  list-style: none;
  margin: 0;
  padding: 0 18px 14px;
}

.page-about .about-tree__list li {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 16px;
  padding: 10px 0;
  border-top: 1px solid var(--line-soft);
  font-size: 14.5px;
  color: var(--paper);
}

.page-about .about-tree__note {
  font-size: 13px;
  color: var(--stone);
  text-align: right;
  flex: 0 0 auto;
}

.page-about .about-catalog__side {
  display: grid;
  gap: 12px;
  align-content: start;
  border-left: 2px solid var(--electric);
  padding: 4px 0 4px 18px;
}

.page-about .about-catalog__side p {
  margin: 0;
  font-size: 15px;
  line-height: 1.76;
  color: var(--silver);
}

.page-about .about-catalog__side .btn {
  justify-self: start;
}

.page-about .about-catalog__hint {
  margin-top: 6px;
  font-size: 14px;
  color: var(--stone);
}

/* ---------- 覆盖范围 ---------- */

.page-about .about-reach {
  position: relative;
  overflow: hidden;
  border-top: 1px solid var(--line-soft);
  border-bottom: 1px solid var(--line-soft);
  background: var(--ink-2);
  padding: clamp(56px, 9vw, 104px) 0;
}

.page-about .about-reach__bg {
  position: absolute;
  inset: 0;
  z-index: 0;
}

.page-about .about-reach__bg img {
  display: block;
  width: 100%;
  height: 100%;
  max-width: none;
  object-fit: cover;
  opacity: 0.34;
}

.page-about .about-reach__bg::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(
    100deg,
    var(--ink) 6%,
    rgba(11, 27, 58, 0.78) 46%,
    rgba(11, 27, 58, 0.26) 100%
  );
}

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

.page-about .about-reach__lead {
  max-width: 58ch;
  font-size: 16px;
  line-height: 1.8;
  color: var(--silver);
}

.page-about .about-reach__stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 22px 24px;
  margin: 26px 0 0;
}

.page-about .about-reach__stats > div {
  border-top: 1px solid var(--line);
  padding-top: 12px;
}

.page-about .about-reach__stats dt {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.12em;
  color: var(--stone);
  margin-bottom: 8px;
}

.page-about .about-reach__stats dd {
  margin: 0;
  font-family: var(--font-mono);
  font-size: clamp(26px, 4.4vw, 36px);
  font-weight: 700;
  line-height: 1.1;
  color: var(--paper);
  letter-spacing: -0.02em;
}

.page-about .about-reach__stats dd small {
  margin-left: 6px;
  font-family: var(--font-sans);
  font-size: 13px;
  font-weight: 400;
  letter-spacing: 0;
  color: var(--silver);
}

.page-about .about-reach__note {
  max-width: 56ch;
  margin: 26px 0 0;
  font-size: 14.5px;
  line-height: 1.78;
  color: var(--stone);
}

/* ---------- 内容准则 ---------- */

.page-about .about-rules {
  padding: clamp(48px, 8vw, 92px) 0;
}

.page-about .about-rules__list {
  list-style: none;
  counter-reset: rule;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: 1fr;
  gap: 26px;
}

.page-about .about-rules__list li {
  counter-increment: rule;
  border-top: 1px solid var(--line);
  padding-top: 16px;
}

.page-about .about-rules__list li::before {
  content: "0" counter(rule);
  display: block;
  margin-bottom: 8px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--electric);
}

.page-about .about-rules__list h3 {
  margin: 0 0 8px;
  font-size: 18px;
}

.page-about .about-rules__list p {
  margin: 0;
  font-size: 15px;
  line-height: 1.78;
  color: var(--silver);
}

.page-about .about-rules__foot {
  display: grid;
  grid-template-columns: 1fr;
  gap: 14px;
  align-items: center;
  margin-top: clamp(28px, 4vw, 42px);
  padding: 20px;
  border: 1px solid var(--line);
  border-left: 3px solid var(--gold);
  background: var(--ink-2);
}

.page-about .about-rules__foot p {
  margin: 0;
  font-size: 15px;
  line-height: 1.76;
  color: var(--silver);
}

.page-about .about-rules__foot .btn,
.page-about .about-rules__foot .about-link {
  justify-self: start;
  font-size: 15px;
}

/* ---------- 响应式 ---------- */

@media (min-width: 760px) {
  .page-about .about-team__list {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .page-about .about-reach__stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 0 28px;
  }

  .page-about .about-rules__list {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 28px;
  }

  .page-about .about-rules__foot {
    grid-template-columns: minmax(0, 1fr) auto;
    gap: 12px 20px;
  }

  .page-about .about-rules__foot p {
    grid-column: 1 / -1;
  }
}

@media (min-width: 900px) {
  .page-about .about-intro__grid {
    grid-template-columns: minmax(0, 1.6fr) minmax(260px, 1fr);
  }

  .page-about .about-why__grid {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, 1fr);
    gap: 56px;
  }

  .page-about .about-history__grid {
    grid-template-columns: minmax(0, 1.55fr) minmax(240px, 1fr);
    gap: 56px;
  }

  .page-about .about-gauge {
    position: sticky;
    top: calc(var(--header-h-slim) + 20px);
  }

  .page-about .about-flow {
    grid-template-columns: minmax(0, 1.15fr) minmax(0, 1fr);
    gap: 48px;
  }

  .page-about .about-catalog__grid {
    grid-template-columns: minmax(0, 1.6fr) minmax(240px, 1fr);
    gap: 56px;
  }
}
<<<END>>>