/* ===== 页面作用域基础 ===== */
.page-about {
  --about-hair: rgba(42, 92, 122, .3);
  --about-dark-panel: rgba(20, 60, 52, .66);
  --about-frost-soft: rgba(244, 250, 252, .78);
  --about-on-dark: rgba(244, 250, 252, .8);
  background: linear-gradient(180deg, var(--ice) 0%, var(--frost) 34%, var(--ice) 100%);
  color: var(--text);
  overflow-x: hidden;
}

.page-about h1,
.page-about h2,
.page-about h3 {
  margin: 0;
  font-family: var(--font-sans);
  font-weight: 900;
  letter-spacing: -.02em;
  line-height: 1.16;
}

.page-about h1 { font-size: clamp(32px, 7.2vw, 56px); }
.page-about h2 { font-size: clamp(24px, 4.6vw, 40px); }
.page-about h3 { font-size: clamp(16px, 2.2vw, 19px); }
.page-about p { margin: 0; line-height: 1.7; }

/* ===== 首屏 ===== */
.page-about .about-hero {
  padding-top: clamp(22px, 5vw, 52px);
  padding-bottom: clamp(30px, 5vw, 60px);
}

.page-about .about-hero-grid {
  display: grid;
  gap: clamp(28px, 5vw, 56px);
  align-items: end;
  margin-top: clamp(20px, 3vw, 36px);
}

.page-about .about-hero-lead h1 { margin-top: 14px; }

.page-about .about-lede {
  margin-top: 18px;
  max-width: 56ch;
  font-size: clamp(15px, 1.7vw, 17px);
  color: rgba(15, 31, 29, .84);
}

.page-about .about-lede--dark { color: var(--about-on-dark); }

.page-about .about-hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: clamp(22px, 3vw, 30px);
}

.page-about .about-hero-panel {
  padding: clamp(24px, 3.4vw, 36px);
  background: linear-gradient(158deg, var(--ink) 0%, var(--ink-2) 66%, var(--indigo) 150%);
  color: var(--frost);
  clip-path: var(--cut-shell);
}

.page-about .about-hero-panel .label { color: var(--cyan); }

.page-about .about-nums {
  list-style: none;
  margin: 20px 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 20px 16px;
}

.page-about .about-nums li {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding-left: 12px;
  border-left: 2px solid var(--cyan);
}

.page-about .about-nums .num {
  color: var(--cyan);
  font-size: clamp(26px, 5.4vw, 38px);
  line-height: 1;
}

.page-about .about-num-cap {
  font-size: 12.5px;
  line-height: 1.45;
  color: var(--about-on-dark);
}

/* ===== 开篇图 ===== */
.page-about .about-opening { padding-top: 0; }

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

/* ===== 我们做的是什么 ===== */
.page-about .about-split {
  display: grid;
  gap: clamp(28px, 4vw, 48px);
}

.page-about .about-split-main h2 { margin-top: 12px; }
.page-about .about-split-main p { margin-top: 16px; max-width: 62ch; }

.page-about .about-split-aside {
  display: grid;
  gap: 16px;
  align-content: start;
}

.page-about .about-split-aside .panel {
  padding: clamp(20px, 2.8vw, 28px);
}

.page-about .about-split-aside p {
  font-size: 15px;
  color: rgba(15, 31, 29, .8);
}

.page-about .about-aside-tag {
  font-family: var(--font-mono) !important;
  font-size: 12px;
  letter-spacing: .1em;
  text-transform: uppercase;
  color: var(--indigo);
  margin-bottom: 10px;
}

/* ===== 赛季刻度线 ===== */
.page-about .about-era h2 { margin-top: 12px; }

.page-about .timeline {
  list-style: none;
  position: relative;
  margin: clamp(28px, 4.4vw, 52px) 0 0;
  padding: 0 0 0 30px;
  display: grid;
  gap: 10px;
}

.page-about .timeline::before {
  content: "";
  position: absolute;
  left: 6px;
  top: 12px;
  bottom: 12px;
  width: 2px;
  background: linear-gradient(180deg, var(--cyan) 0%, var(--indigo) 58%, var(--orange) 100%);
  opacity: .85;
}

.page-about .timeline li { position: relative; }

.page-about .era-dot {
  position: absolute;
  left: -23px;
  top: 27px;
  width: 10px;
  height: 10px;
  background: var(--cyan);
  transform: translate(-50%, -50%) rotate(45deg);
  box-shadow: 0 0 0 3px rgba(11, 42, 37, .9);
  transition: background .22s var(--ease);
}

.page-about .era {
  background: var(--about-dark-panel);
  clip-path: var(--cut-sm);
  transition: background .22s var(--ease);
}

.page-about .era[open] { background: rgba(20, 60, 52, .92); }

.page-about .era summary {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 15px 18px;
  cursor: pointer;
  list-style: none;
}

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

.page-about .era summary:focus-visible {
  outline: none;
  box-shadow: inset 0 0 0 2px var(--orange);
}

.page-about .era-season {
  flex: 0 0 auto;
  font-size: 13px;
  letter-spacing: .08em;
  color: var(--cyan);
}

.page-about .era-name {
  flex: 1 1 auto;
  font-weight: 700;
  font-size: clamp(15px, 1.7vw, 17px);
  color: var(--frost);
}

.page-about .era-plus {
  position: relative;
  flex: 0 0 15px;
  width: 15px;
  height: 15px;
}

.page-about .era-plus::before,
.page-about .era-plus::after {
  content: "";
  position: absolute;
  background: var(--cyan);
  transition: transform .22s var(--ease);
}

.page-about .era-plus::before { left: 0; top: 6px; width: 15px; height: 2px; }
.page-about .era-plus::after  { left: 6px; top: 0; width: 2px; height: 15px; }

.page-about .era[open] .era-plus::after { transform: scaleY(0); }

.page-about .era-body { padding: 0 18px 18px; }

.page-about .era-body p {
  font-size: 15px;
  color: var(--about-on-dark);
  max-width: 68ch;
}

.page-about .about-era-figure {
  margin: clamp(32px, 5vw, 58px) 0 0;
}

/* ===== 团队分工 ===== */
.page-about .about-team h2 { margin-top: 12px; }

.page-about .team-bars {
  list-style: none;
  margin: clamp(28px, 4.4vw, 48px) 0 0;
  padding: 0;
  display: grid;
  gap: clamp(22px, 3vw, 32px);
}

.page-about .bar-head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 12px;
}

.page-about .bar-name {
  font-weight: 700;
  font-size: clamp(16px, 2vw, 19px);
}

.page-about .bar-num {
  font-size: clamp(24px, 3.6vw, 34px);
  color: var(--ink);
  transition: color .22s var(--ease);
}

.page-about .team-bars li:hover .bar-num,
.page-about .team-bars li:focus-within .bar-num { color: var(--indigo); }

.page-about .bar-track {
  margin-top: 10px;
  height: 10px;
  background: rgba(42, 92, 122, .16);
  clip-path: var(--cut-sm);
  overflow: hidden;
}

.page-about .bar-fill {
  display: block;
  height: 100%;
  width: 0;
  transition: width .6s var(--ease);
}

.page-about .bar-fill--content { width: 56.5%; background: linear-gradient(90deg, var(--indigo), var(--cyan)); }
.page-about .bar-fill--data    { width: 30.5%; background: linear-gradient(90deg, var(--indigo), var(--orange)); }
.page-about .bar-fill--lang    { width: 13%;   background: linear-gradient(90deg, var(--steel), var(--indigo)); }

.page-about .bar-note {
  margin-top: 10px;
  max-width: 66ch;
  font-size: 14.5px;
  color: rgba(15, 31, 29, .78);
}

/* ===== 数据来源 ===== */
.page-about .about-source-grid {
  display: grid;
  gap: clamp(28px, 4.4vw, 52px);
  align-items: center;
}

.page-about .about-source-copy h2 { margin-top: 12px; }

.page-about .tab-list {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: clamp(20px, 2.8vw, 28px);
}

.page-about .tab {
  font: inherit;
  font-size: 13.5px;
  letter-spacing: .04em;
  padding: 9px 18px;
  border: 1px solid rgba(53, 224, 200, .42);
  background: transparent;
  color: var(--frost);
  clip-path: var(--cut-sm);
  cursor: pointer;
  transition: background .2s var(--ease), color .2s var(--ease), border-color .2s var(--ease);
}

.page-about .tab:hover { border-color: var(--cyan); }

.page-about .tab[aria-selected="true"] {
  background: var(--cyan);
  border-color: var(--cyan);
  color: var(--text);
}

.page-about .tab:focus-visible {
  outline: 2px solid var(--orange);
  outline-offset: 3px;
}

.page-about .tab-panel {
  margin-top: 18px;
  padding: clamp(18px, 2.6vw, 24px);
  background: rgba(11, 42, 37, .55);
  clip-path: var(--cut-panel);
  color: var(--about-on-dark);
  font-size: 15px;
}

.page-about .about-source-figure { margin: 0; }

/* ===== 内容标准与合作生态 ===== */
.page-about .about-standard h2 { margin-top: 12px; }

.page-about .standard-grid {
  display: grid;
  gap: clamp(16px, 2.4vw, 24px);
  margin-top: clamp(28px, 4.4vw, 44px);
}

.page-about .standard-card {
  padding: clamp(22px, 2.8vw, 30px);
  background: var(--about-frost-soft);
  border-top: 3px solid var(--indigo);
  clip-path: var(--cut-panel);
}

.page-about .standard-card h3 { margin-bottom: 10px; }

.page-about .standard-card p {
  font-size: 14.8px;
  color: rgba(15, 31, 29, .8);
}

.page-about .standard-en {
  display: block;
  margin-bottom: 8px;
  font-family: var(--font-serif);
  font-style: italic;
  font-size: 14px;
  color: var(--indigo);
  letter-spacing: .02em;
}

/* ===== 承诺区 ===== */
.page-about .about-promise h2 { margin-top: 12px; }

.page-about .promise-list {
  list-style: none;
  margin: clamp(26px, 4vw, 42px) 0 0;
  padding: 0;
  display: grid;
  gap: 16px;
}

.page-about .promise-list li {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 16px;
  padding: 18px;
  background: rgba(53, 224, 200, .07);
  border-left: 3px solid var(--orange);
}

.page-about .promise-num {
  font-size: clamp(19px, 2.6vw, 25px);
  line-height: 1.1;
  color: var(--cyan);
}

.page-about .promise-list h3 {
  margin-bottom: 6px;
  color: var(--frost);
}

.page-about .promise-list p {
  font-size: 14.5px;
  color: var(--about-on-dark);
}

.page-about .about-cta {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: clamp(28px, 4vw, 42px);
}

/* ===== 响应式 ===== */
@media (min-width: 760px) {
  .page-about .about-split-aside { gap: 18px; }

  .page-about .promise-list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 20px 24px;
  }

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

@media (min-width: 900px) {
  .page-about .about-hero-grid {
    grid-template-columns: minmax(0, 1.2fr) minmax(0, .8fr);
  }

  .page-about .timeline {
    padding-left: 46px;
    gap: 12px;
  }

  .page-about .timeline::before { left: 10px; }
  .page-about .era-dot { left: -35px; }

  .page-about .era summary { padding: 18px 24px; }
  .page-about .era-body { padding: 0 24px 22px; }
}

@media (min-width: 960px) {
  .page-about .about-split {
    grid-template-columns: minmax(0, 1.35fr) minmax(0, .85fr);
    align-items: start;
  }

  .page-about .about-source-grid {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, .95fr);
  }

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

@media (prefers-reduced-motion: reduce) {
  .page-about .bar-fill,
  .page-about .era-plus::before,
  .page-about .era-plus::after,
  .page-about .era-dot,
  .page-about .bar-num,
  .page-about .tab { transition: none; }
}
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