.page-about {
  --about-seg-1: #143B5E;
  --about-seg-2: #2A6288;
  --about-seg-3: #1F8A7A;
  --about-seg-4: #5E7A93;
  --about-panel: rgba(20, 59, 94, 0.34);
  --about-panel-strong: rgba(20, 59, 94, 0.58);
  --about-hair: rgba(120, 142, 164, 0.24);

  padding-bottom: clamp(48px, 8vw, 96px);
  color: var(--mist-200);
}

.page-about .about-crumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  padding-top: clamp(18px, 3.5vw, 34px);
  font-size: var(--step-12);
  letter-spacing: 0.08em;
  color: var(--slate-500);
}

.page-about .about-crumb a {
  color: var(--slate-500);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color 0.18s var(--ease-out), border-color 0.18s var(--ease-out);
}

.page-about .about-crumb a:hover,
.page-about .about-crumb a:focus-visible {
  color: var(--sand-200);
  border-bottom-color: var(--sand-200);
}

.page-about .about-crumb [aria-current="page"] {
  color: var(--sand-500);
}

.page-about .about-crumb__sep {
  color: rgba(120, 142, 164, 0.55);
}

/* ---------- 首屏 ---------- */

.page-about .about-hero {
  padding: clamp(26px, 5.6vw, 60px) 0 clamp(34px, 6vw, 70px);
}

.page-about .eyebrow {
  margin: 0 0 12px;
  color: var(--sand-500);
  letter-spacing: 0.16em;
}

.page-about .about-hero__title {
  margin: 0 0 0.55em;
  max-width: 20ch;
  font-size: clamp(1.95rem, 6vw, 4.2rem);
  font-weight: 900;
  line-height: 1.08;
  letter-spacing: -0.02em;
  color: var(--paper-50);
}

.page-about .about-hero__lead {
  margin: 0 0 clamp(24px, 4vw, 40px);
  max-width: 62ch;
  font-size: clamp(1rem, 1.5vw, 1.375rem);
  line-height: 1.85;
  color: var(--mist-200);
}

.page-about .about-hero__facts {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: clamp(18px, 3vw, 32px);
  margin: 0;
  padding: clamp(20px, 3vw, 30px) 0 0;
  list-style: none;
  border-top: 1px solid var(--about-hair);
}

.page-about .about-hero__fact {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.page-about .about-hero__num {
  font-family: var(--font-mono);
  font-size: clamp(1.8rem, 4.4vw, 2.75rem);
  font-weight: 500;
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--sand-500);
}

.page-about .about-hero__cap {
  font-size: var(--step-12);
  letter-spacing: 0.06em;
  line-height: 1.5;
  color: var(--slate-500);
}

/* ---------- 章节骨架 ---------- */

.page-about .about-section {
  padding: clamp(40px, 7vw, 84px) 0;
  border-top: 1px solid var(--about-hair);
}

.page-about .about-section--join {
  border-bottom: 1px solid var(--about-hair);
}

.page-about .about-split {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(26px, 5vw, 54px);
}

.page-about .about-main {
  min-width: 0;
}

.page-about .about-h2 {
  margin: 0 0 0.72em;
  max-width: 22ch;
  font-size: clamp(1.4rem, 3.4vw, 2rem);
  font-weight: 900;
  line-height: 1.22;
  letter-spacing: -0.01em;
  color: var(--paper-50);
}

.page-about .about-p {
  margin: 0 0 1.15em;
  max-width: 68ch;
  font-size: var(--step-17);
  line-height: 1.85;
  color: var(--mist-200);
}

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

/* ---------- 数字侧栏 ---------- */

.page-about .about-aside {
  display: grid;
  gap: clamp(16px, 2.6vw, 24px);
  align-self: start;
  min-width: 0;
  padding: clamp(20px, 3vw, 30px);
  border: 1px solid var(--about-hair);
  border-radius: var(--radius-lg);
  background:
    radial-gradient(130% 90% at 100% 0%, rgba(224, 177, 94, 0.11), transparent 62%),
    linear-gradient(160deg, var(--about-panel-strong), rgba(6, 23, 38, 0.94));
}

.page-about .about-aside__title {
  margin: 0;
  font-size: var(--step-12);
  font-weight: 500;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--slate-500);
}

.page-about .about-aside__list {
  display: grid;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .about-aside__row {
  display: flex;
  flex-direction: column;
  gap: 5px;
  padding: 14px 0;
  border-top: 1px solid var(--about-hair);
}

.page-about .about-aside__row:first-child {
  padding-top: 0;
  border-top: 0;
}

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

.page-about .about-aside__value {
  font-family: var(--font-mono);
  font-size: clamp(1.45rem, 3vw, 2rem);
  font-weight: 500;
  line-height: 1.05;
  letter-spacing: -0.02em;
  color: var(--sand-500);
}

.page-about .about-aside__unit {
  margin-left: 5px;
  font-size: 0.42em;
  letter-spacing: 0.06em;
  color: var(--slate-500);
}

.page-about .about-aside__label {
  font-size: var(--step-14);
  line-height: 1.65;
  color: var(--mist-200);
}

.page-about .about-aside__note {
  margin: 0;
  font-size: var(--step-14);
  line-height: 1.75;
  color: var(--slate-500);
}

/* ---------- 图片框 ---------- */

.page-about .media-frame {
  display: block;
  margin: 0;
  border: 1px solid var(--about-hair);
  border-radius: var(--radius-md);
  overflow: hidden;
  background: linear-gradient(150deg, rgba(20, 59, 94, 0.72), rgba(6, 23, 38, 0.92));
}

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

.page-about .about-data-figure,
.page-about .about-history-figure {
  margin-top: clamp(24px, 3.6vw, 38px);
}

.page-about .about-history-figure {
  margin-bottom: clamp(26px, 4vw, 42px);
}

/* ---------- 团队堆叠条形 ---------- */

.page-about .about-bars {
  margin-top: clamp(22px, 3.4vw, 34px);
}

.page-about .about-bar {
  display: flex;
  width: 100%;
  height: 54px;
  border: 1px solid var(--about-hair);
  border-radius: var(--radius-pill);
  overflow: hidden;
  background: rgba(120, 142, 164, 0.1);
}

.page-about .about-bar__seg {
  display: block;
  height: 100%;
  transition: filter 0.18s var(--ease-out);
}

.page-about .about-bar__seg:hover {
  filter: brightness(1.4);
}

.page-about .about-bar__seg--a {
  width: 30.4%;
  background: var(--about-seg-1);
}

.page-about .about-bar__seg--b {
  width: 26.1%;
  background: var(--about-seg-2);
}

.page-about .about-bar__seg--c {
  width: 23.9%;
  background: var(--about-seg-3);
}

.page-about .about-bar__seg--d {
  width: 19.6%;
  background: var(--about-seg-4);
}

.page-about .about-legend {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 10px;
  margin: 18px 0 0;
  padding: 0;
  list-style: none;
}

.page-about .about-legend__item {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: var(--step-14);
  color: var(--mist-200);
}

.page-about .about-legend__dot {
  flex: none;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  box-shadow: 0 0 0 1px rgba(200, 214, 228, 0.3);
}

.page-about .about-legend__dot--a {
  background: var(--about-seg-1);
}

.page-about .about-legend__dot--b {
  background: var(--about-seg-2);
}

.page-about .about-legend__dot--c {
  background: var(--about-seg-3);
}

.page-about .about-legend__dot--d {
  background: var(--about-seg-4);
}

.page-about .about-legend__name {
  flex: 1 1 auto;
  min-width: 0;
}

.page-about .about-legend__count {
  font-family: var(--font-mono);
  font-size: var(--step-17);
  color: var(--sand-500);
}

/* ---------- 比赛日流程 ---------- */

.page-about .about-flow {
  display: grid;
  gap: 12px;
  margin: clamp(22px, 3.4vw, 32px) 0 0;
  padding: 0;
  list-style: none;
}

.page-about .about-flow__node {
  border: 1px solid var(--about-hair);
  border-radius: var(--radius-md);
  background: rgba(20, 59, 94, 0.24);
  transition: border-color 0.18s var(--ease-out), background-color 0.18s var(--ease-out);
}

.page-about .about-flow__node:hover {
  border-color: var(--line-sand);
}

.page-about .about-flow__node[open] {
  border-color: var(--line-sand);
  background: rgba(20, 59, 94, 0.44);
  box-shadow: inset 3px 0 0 var(--sand-500);
}

.page-about .about-flow__summary {
  display: flex;
  align-items: baseline;
  gap: 14px;
  padding: 16px 20px;
  cursor: pointer;
  list-style: none;
}

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

.page-about .about-flow__summary::marker {
  content: "";
}

.page-about .about-flow__summary:focus-visible {
  outline: 2px solid var(--sand-500);
  outline-offset: 2px;
}

.page-about .about-flow__num {
  flex: none;
  min-width: 3.4em;
  font-family: var(--font-mono);
  font-size: var(--step-17);
  letter-spacing: 0.02em;
  color: var(--jade-400);
}

.page-about .about-flow__name {
  font-size: var(--step-17);
  font-weight: 500;
  line-height: 1.5;
  color: var(--paper-50);
}

.page-about .about-flow__text {
  margin: 0;
  padding: 14px 20px 18px;
  max-width: 62ch;
  border-top: 1px solid var(--about-hair);
  font-size: var(--step-14);
  line-height: 1.8;
  color: var(--mist-200);
}

/* ---------- 数据来源三点流程 ---------- */

.page-about .about-chain {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 14px;
  margin: clamp(22px, 3.4vw, 34px) 0 0;
  padding: 0;
  list-style: none;
}

.page-about .about-chain__item {
  position: relative;
  padding: 20px 20px 22px;
  border: 1px solid var(--about-hair);
  border-radius: var(--radius-md);
  background: rgba(20, 59, 94, 0.22);
  transition: border-color 0.18s var(--ease-out);
}

.page-about .about-chain__item:hover {
  border-color: var(--line-sand);
}

.page-about .about-chain__idx {
  display: block;
  margin-bottom: 10px;
  font-family: var(--font-mono);
  font-size: var(--step-14);
  letter-spacing: 0.12em;
  color: var(--coral-400);
}

.page-about .about-chain__name {
  margin: 0 0 6px;
  font-size: var(--step-17);
  font-weight: 500;
  line-height: 1.4;
  color: var(--paper-50);
}

.page-about .about-chain__desc {
  margin: 0;
  font-size: var(--step-14);
  line-height: 1.75;
  color: var(--slate-500);
}

/* ---------- 发展历程时间轴 ---------- */

.page-about .about-timeline {
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .about-timeline__item {
  position: relative;
  padding-left: 34px;
  padding-bottom: clamp(22px, 3.4vw, 34px);
}

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

.page-about .about-timeline__item:not(:last-child)::before {
  content: "";
  position: absolute;
  left: 5px;
  top: 20px;
  bottom: 0;
  width: 1px;
  background: linear-gradient(180deg, rgba(224, 177, 94, 0.55), rgba(224, 177, 94, 0.05));
}

.page-about .about-timeline__dot {
  position: absolute;
  left: 0;
  top: 6px;
  display: block;
  width: 11px;
  height: 11px;
  border-radius: 50%;
  box-shadow: 0 0 0 4px var(--ink-900);
}

.page-about .about-timeline__dot--jade {
  background: var(--jade-400);
}

.page-about .about-timeline__dot--sand {
  background: var(--sand-500);
}

.page-about .about-timeline__mark {
  display: block;
  margin-bottom: 6px;
  font-family: var(--font-mono);
  font-size: var(--step-14);
  letter-spacing: 0.08em;
  color: var(--sand-500);
}

.page-about .about-timeline__title {
  margin: 0 0 6px;
  font-size: var(--step-22);
  font-weight: 500;
  line-height: 1.4;
  color: var(--paper-50);
}

.page-about .about-timeline__text {
  margin: 0;
  max-width: 60ch;
  font-size: var(--step-14);
  line-height: 1.8;
  color: var(--mist-200);
}

/* ---------- 专栏系列 ---------- */

.page-about .about-series {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 12px;
  margin: clamp(20px, 3vw, 28px) 0 clamp(22px, 3vw, 30px);
  padding: 0;
  list-style: none;
}

.page-about .about-series__item {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 10px;
  padding: 16px 18px;
  border: 1px solid var(--about-hair);
  border-radius: var(--radius-md);
  background: rgba(108, 43, 72, 0.16);
  transition: border-color 0.18s var(--ease-out), background-color 0.18s var(--ease-out);
}

.page-about .about-series__item:hover {
  border-color: rgba(224, 177, 94, 0.45);
  background: rgba(108, 43, 72, 0.32);
}

.page-about .about-series__item p {
  margin: 0;
  font-size: var(--step-14);
  line-height: 1.7;
  color: var(--mist-200);
}

/* ---------- 链接与按钮 ---------- */

.page-about .about-link {
  display: inline-block;
  padding-bottom: 2px;
  font-size: var(--step-17);
  color: var(--sand-200);
  text-decoration: none;
  border-bottom: 1px solid var(--line-sand);
  transition: color 0.18s var(--ease-out), border-color 0.18s var(--ease-out);
}

.page-about .about-link:hover,
.page-about .about-link:focus-visible {
  color: var(--sand-500);
  border-bottom-color: var(--sand-500);
}

.page-about .about-cta {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: clamp(20px, 3vw, 30px);
}

/* ---------- 自适应 ---------- */

@media (min-width: 560px) {
  .page-about .about-legend {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

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

@media (min-width: 760px) {
  .page-about .about-hero__facts {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

@media (min-width: 960px) {
  .page-about .about-split {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
  }

  .page-about .about-split--history {
    align-items: start;
  }
}

@media (min-width: 1080px) {
  .page-about .about-chain {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 24px;
  }

  .page-about .about-chain__item:not(:last-child)::after {
    content: "";
    position: absolute;
    top: 50%;
    right: -24px;
    width: 24px;
    height: 1px;
    background: var(--sand-500);
    opacity: 0.6;
  }
}