.page-about {
  --about-rule: rgba(44, 116, 179, 0.22);
  --about-rule-strong: rgba(44, 116, 179, 0.42);
  background: var(--c-paper);
  color: var(--c-ink);
}

/* ---------- 面包屑 ---------- */
.page-about .about-crumb {
  padding: 16px 0 0;
}

.page-about .about-crumb .breadcrumbs {
  margin: 0;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  color: var(--c-white);
  background:
    radial-gradient(90% 70% at 88% 6%, rgba(34, 224, 196, 0.18), transparent 62%),
    radial-gradient(70% 60% at 6% 100%, rgba(255, 106, 19, 0.16), transparent 60%),
    var(--c-900);
  padding: clamp(30px, 5vw, 62px) 0 clamp(48px, 7vw, 88px);
}

.page-about .about-hero__inner {
  position: relative;
  z-index: 1;
  display: grid;
  gap: clamp(14px, 2.2vw, 24px);
}

.page-about .about-hero__eyebrow {
  margin: 0;
  color: var(--c-orange-soft);
  letter-spacing: 0.16em;
  font-size: var(--fs-xs);
}

.page-about .about-hero__title {
  margin: 0;
  font-size: clamp(2rem, 5.2vw, 3.4rem);
  line-height: 1.08;
  letter-spacing: -0.02em;
  font-weight: 900;
  max-width: 18ch;
}

.page-about .about-hero__lead {
  margin: 0;
  max-width: 58ch;
  color: rgba(255, 255, 255, 0.82);
  font-size: clamp(0.95rem, 1.4vw, 1.05rem);
  line-height: 1.8;
}

.page-about .about-hero__stats {
  list-style: none;
  margin: clamp(8px, 2vw, 20px) 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: rgba(255, 255, 255, 0.14);
  border: 1px solid rgba(255, 255, 255, 0.14);
}

.page-about .about-hero__stat {
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding: 14px 16px;
  background: rgba(6, 35, 63, 0.55);
}

.page-about .about-hero__num {
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: clamp(1.5rem, 3vw, 2rem);
  line-height: 1;
  color: var(--c-cyan);
}

.page-about .about-hero__lbl {
  font-size: var(--fs-xs);
  line-height: 1.6;
  color: rgba(255, 255, 255, 0.72);
}

.page-about .about-hero__rail {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 10px;
  opacity: 0.55;
  background-image: repeating-linear-gradient(
    90deg,
    rgba(34, 224, 196, 0.6) 0 1px,
    transparent 1px 28px
  );
}

/* ---------- 骨架 ---------- */
.page-about .about-shell {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(24px, 4vw, 44px);
  padding-top: clamp(28px, 4vw, 56px);
  padding-bottom: clamp(40px, 6vw, 80px);
}

/* ---------- 章节索引 ---------- */
.page-about .about-rail__title {
  display: none;
}

.page-about .about-rail__list {
  list-style: none;
  margin: 0;
  padding: 0 0 2px;
  display: flex;
  gap: 8px;
  overflow-x: auto;
  scrollbar-width: none;
}

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

.page-about .about-rail__link {
  display: inline-flex;
  align-items: baseline;
  gap: 8px;
  padding: 8px 14px;
  white-space: nowrap;
  text-decoration: none;
  color: var(--c-ink);
  font-size: var(--fs-sm);
  background: var(--c-white);
  border: 1px solid var(--about-rule);
  border-radius: var(--radius);
  transition: border-color var(--dur) var(--ease), background var(--dur) var(--ease), color var(--dur) var(--ease);
}

.page-about .about-rail__link:hover,
.page-about .about-rail__link:focus-visible {
  border-color: var(--c-orange);
  color: var(--c-700);
}

.page-about .about-rail__num {
  font-family: var(--font-mono);
  font-size: var(--fs-xs);
  letter-spacing: 0.08em;
  color: var(--c-orange);
}

/* ---------- 章节卡 ---------- */
.page-about .about-chapter {
  position: relative;
  background: var(--c-white);
  border-top: 2px solid var(--c-700);
  padding: clamp(20px, 3vw, 36px);
  margin-bottom: clamp(24px, 4vw, 44px);
  box-shadow: var(--shadow-lift);
}

.page-about .about-chapter::before {
  content: "";
  position: absolute;
  top: 0;
  right: 0;
  width: 72px;
  height: 72px;
  background: linear-gradient(225deg, var(--c-cyan-soft) 0%, rgba(201, 251, 242, 0) 72%);
  opacity: 0.7;
  pointer-events: none;
}

.page-about .about-archive > .about-chapter:last-child {
  margin-bottom: 0;
}

.page-about .about-chapter__head {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 12px;
  margin: 0 0 clamp(14px, 2vw, 22px);
}

.page-about .about-chapter__num {
  font-size: var(--fs-xs);
  letter-spacing: 0.14em;
  color: var(--c-orange);
  border: 1px solid currentColor;
  padding: 2px 6px;
}

.page-about .about-chapter__title {
  margin: 0;
  font-size: clamp(1.3rem, 2.4vw, 1.75rem);
  line-height: var(--lh-tight);
  letter-spacing: -0.02em;
  font-weight: 900;
  color: var(--c-900);
}

.page-about .about-chapter__body p {
  margin: 0 0 1em;
  max-width: 62ch;
  font-size: var(--fs-body);
  line-height: var(--lh-body);
  color: var(--c-ink);
}

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

.page-about .about-lede {
  font-size: clamp(1.05rem, 1.7vw, 1.2rem) !important;
  font-weight: 500;
  line-height: 1.65;
  color: var(--c-700);
  border-left: 3px solid var(--c-cyan);
  padding-left: 14px;
}

.page-about .about-link {
  color: var(--c-700);
  text-decoration: none;
  border-bottom: 1px solid var(--c-orange);
  padding-bottom: 1px;
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.page-about .about-link:hover,
.page-about .about-link:focus-visible {
  color: var(--c-orange);
}

/* ---------- 发展脉络 ---------- */
.page-about .about-miles {
  list-style: none;
  margin: clamp(20px, 3vw, 30px) 0;
  padding: 0;
  border-top: 1px solid var(--about-rule);
}

.page-about .about-miles__item {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 6px;
  padding: 16px 0;
  border-bottom: 1px dashed var(--about-rule);
}

.page-about .about-miles__key {
  color: var(--c-orange);
  letter-spacing: 0.12em;
  padding-top: 2px;
}

.page-about .about-miles__text h3 {
  margin: 0 0 4px;
  font-size: var(--fs-5);
  font-weight: 700;
  color: var(--c-900);
}

.page-about .about-miles__text p {
  margin: 0;
  max-width: none;
  font-size: var(--fs-sm);
  line-height: 1.7;
  color: var(--c-muted);
}

/* ---------- 双栏 ---------- */
.page-about .about-split {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(18px, 3vw, 32px);
  margin: clamp(16px, 2.4vw, 26px) 0;
}

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

.page-about .about-figure .media,
.page-about .about-wide .media {
  border-radius: var(--radius);
  overflow: hidden;
}

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

.page-about .about-figure__cap {
  display: block;
  margin-top: 8px;
  color: var(--c-muted);
  font-size: var(--fs-xs);
  letter-spacing: 0.08em;
}

.page-about .about-wide {
  margin: clamp(20px, 3vw, 30px) 0;
}

/* ---------- 流程刻度 ---------- */
.page-about .about-flow {
  list-style: none;
  margin: clamp(20px, 3vw, 28px) 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 2px;
  background: var(--about-rule);
  border: 1px solid var(--about-rule);
}

.page-about .about-flow__step {
  position: relative;
  padding: 16px 14px;
  background: var(--c-paper);
}

.page-about .about-flow__n {
  display: block;
  width: 22px;
  height: 22px;
  margin-bottom: 10px;
  font-family: var(--font-mono);
  font-size: var(--fs-xs);
  line-height: 22px;
  text-align: center;
  color: var(--c-cyan);
  background: var(--c-900);
}

.page-about .about-flow__t {
  margin: 0 0 6px;
  font-size: var(--fs-sm);
  font-weight: 700;
  color: var(--c-700);
}

.page-about .about-flow__d {
  margin: 0;
  font-size: var(--fs-xs);
  line-height: 1.65;
  color: var(--c-muted);
}

.page-about .about-flow__step:last-child {
  background: var(--c-900);
}

.page-about .about-flow__step:last-child .about-flow__t {
  color: var(--c-white);
}

.page-about .about-flow__step:last-child .about-flow__d {
  color: rgba(255, 255, 255, 0.72);
}

.page-about .about-flow__step:last-child .about-flow__n {
  background: var(--c-orange);
  color: var(--c-900);
}

/* ---------- 展开组 ---------- */
.page-about .expand {
  margin: clamp(18px, 3vw, 26px) 0;
  background: var(--c-paper);
  border: 1px solid var(--about-rule);
}

.page-about .expand__trigger {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  width: 100%;
  padding: 14px 16px;
  font: inherit;
  font-weight: 700;
  text-align: left;
  color: var(--c-700);
  background: none;
  border: 0;
  cursor: pointer;
  transition: color var(--dur) var(--ease);
}

.page-about .expand__trigger:hover,
.page-about .expand__trigger:focus-visible {
  color: var(--c-orange);
}

.page-about .expand__body {
  padding: 0 16px 16px;
}

.page-about .expand__body ul {
  margin: 0;
  padding-left: 18px;
}

.page-about .expand__body li {
  margin-bottom: 6px;
  font-size: var(--fs-sm);
  line-height: 1.75;
  color: var(--c-ink);
}

.page-about .expand__body li:last-child {
  margin-bottom: 0;
}

.page-about .expand__body strong {
  color: var(--c-700);
}

/* ---------- 赛区网络图 ---------- */
.page-about .about-netwrap {
  margin: clamp(20px, 3vw, 30px) 0;
  padding: clamp(12px, 2vw, 20px);
  background: linear-gradient(135deg, rgba(201, 251, 242, 0.5), var(--c-paper) 62%);
  border: 1px solid var(--about-rule);
}

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

.page-about .about-net__link,
.page-about .about-net__links path {
  fill: none;
  stroke: var(--c-400);
  stroke-width: 1.5;
  stroke-dasharray: 5 6;
  opacity: 0.7;
}

.page-about .about-net__node {
  outline: none;
}

.page-about .about-net__node rect {
  fill: var(--c-white);
  stroke: var(--about-rule-strong);
  stroke-width: 1;
  transition: fill var(--dur) var(--ease), stroke var(--dur) var(--ease);
}

.page-about .about-net__node:hover rect,
.page-about .about-net__node:focus-visible rect {
  fill: var(--c-cyan-soft);
  stroke: var(--c-cyan);
  stroke-width: 2;
}

.page-about .about-net__k {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  fill: var(--c-muted);
}

.page-about .about-net__v {
  font-family: var(--font-body);
  font-size: 14px;
  font-weight: 700;
  fill: var(--c-ink);
}

.page-about .about-net__node--core rect {
  fill: var(--c-900);
  stroke: var(--c-900);
}

.page-about .about-net__node--core .about-net__k {
  fill: rgba(255, 255, 255, 0.6);
}

.page-about .about-net__node--core .about-net__v {
  fill: var(--c-white);
}

.page-about .about-net__node--core:hover rect,
.page-about .about-net__node--core:focus-visible rect {
  fill: var(--c-700);
  stroke: var(--c-cyan);
}

.page-about .about-net__node--out rect {
  stroke: var(--c-orange);
}

.page-about .about-netwrap__cap {
  margin-top: 10px;
  font-size: var(--fs-xs);
  line-height: 1.7;
  color: var(--c-muted);
}

/* ---------- 数据格 ---------- */
.page-about .about-facts {
  list-style: none;
  margin: clamp(20px, 3vw, 28px) 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 2px;
  background: var(--about-rule);
  border: 1px solid var(--about-rule);
}

.page-about .about-facts__item {
  background: var(--c-white);
  padding: 18px 16px;
}

.page-about .about-facts__num {
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: clamp(1.8rem, 3vw, 2.4rem);
  line-height: 1;
  color: var(--c-700);
}

.page-about .about-facts__unit {
  margin-left: 4px;
  font-size: var(--fs-sm);
  font-weight: 700;
  color: var(--c-orange);
}

.page-about .about-facts__desc {
  margin: 8px 0 0;
  max-width: none;
  font-size: var(--fs-sm);
  line-height: 1.7;
  color: var(--c-muted);
}

/* ---------- 结尾引导 ---------- */
.page-about .about-cta {
  position: relative;
  overflow: hidden;
  color: var(--c-white);
  background: var(--c-900);
  padding: clamp(32px, 5vw, 64px) 0;
}

.page-about .about-cta::after {
  content: "";
  position: absolute;
  top: -40%;
  right: -10%;
  width: 60%;
  height: 180%;
  background: linear-gradient(120deg, rgba(255, 106, 19, 0.22), rgba(255, 106, 19, 0) 62%);
  transform: rotate(8deg);
  pointer-events: none;
}

.page-about .about-cta__inner {
  position: relative;
  z-index: 1;
  display: grid;
  gap: 18px;
}

.page-about .about-cta__title {
  margin: 0 0 8px;
  font-size: var(--fs-3);
  line-height: 1.3;
  letter-spacing: -0.02em;
  color: var(--c-white);
}

.page-about .about-cta__text {
  margin: 0;
  max-width: 52ch;
  font-size: var(--fs-sm);
  line-height: 1.75;
  color: rgba(255, 255, 255, 0.75);
}

/* ---------- 响应式 ---------- */
@media (min-width: 640px) {
  .page-about .about-miles__item {
    grid-template-columns: 92px minmax(0, 1fr);
    gap: 18px;
    align-items: start;
  }
}

@media (min-width: 700px) {
  .page-about .about-facts {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

@media (min-width: 800px) {
  .page-about .about-split {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
    align-items: start;
  }

  .page-about .about-cta__inner {
    grid-template-columns: minmax(0, 1fr) auto;
    align-items: center;
    gap: 32px;
  }
}

@media (min-width: 820px) {
  .page-about .about-flow {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

@media (min-width: 860px) {
  .page-about .about-hero__stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

@media (min-width: 960px) {
  .page-about .about-shell {
    grid-template-columns: 210px minmax(0, 1fr);
    gap: clamp(32px, 4vw, 64px);
  }

  .page-about .about-rail {
    position: sticky;
    top: calc(var(--header-h) + 28px);
    align-self: start;
  }

  .page-about .about-rail__title {
    display: block;
    margin: 0 0 14px;
    color: var(--c-muted);
    font-size: var(--fs-xs);
    letter-spacing: 0.12em;
  }

  .page-about .about-rail__list {
    flex-direction: column;
    gap: 0;
    overflow: visible;
    padding-bottom: 0;
    border-left: 1px solid var(--about-rule);
  }

  .page-about .about-rail__link {
    position: relative;
    display: flex;
    padding: 12px 10px 12px 18px;
    white-space: normal;
    background: none;
    border: 0;
    border-radius: 0;
    font-size: var(--fs-sm);
    color: var(--c-muted);
  }

  .page-about .about-rail__link::before {
    content: "";
    position: absolute;
    left: -1px;
    top: 12px;
    bottom: 12px;
    width: 2px;
    background: var(--c-orange);
    transform: scaleY(0);
    transform-origin: top;
    transition: transform var(--dur) var(--ease);
  }

  .page-about .about-rail__link:hover,
  .page-about .about-rail__link:focus-visible {
    color: var(--c-900);
  }

  .page-about .about-rail__link:hover::before,
  .page-about .about-rail__link:focus-visible::before {
    transform: scaleY(1);
  }
}
<<<END>>>