.page-about {
  --about-edge: 18px;
  --about-rail: 260px;
}

.page-about .about-wrap {
  width: 100%;
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 var(--about-edge);
}

@media (min-width: 768px) {
  .page-about { --about-edge: var(--edge); }
}

/* ---------- 首屏 ---------- */

.page-about .hero {
  padding: 44px 0 40px;
  border-bottom: 1px solid var(--rail);
}

.page-about .hero__grid {
  display: grid;
  gap: 28px;
  margin-top: 24px;
}

@media (min-width: 940px) {
  .page-about .hero__grid {
    grid-template-columns: 7fr 5fr;
    gap: var(--gutter);
    align-items: end;
  }
}

.page-about .hero__idx {
  margin: 0 0 14px;
  font-size: 12px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--cyan);
}

.page-about .hero__title {
  margin: 0;
  font-family: var(--f-display);
  font-weight: 900;
  font-size: clamp(36px, 7.4vw, 82px);
  line-height: 0.98;
  letter-spacing: -0.03em;
  color: var(--ink);
  max-width: 14ch;
}

.page-about .hero__deck {
  margin: 0;
  font-size: var(--fs-body);
  line-height: 1.75;
  color: var(--ink-dim);
  max-width: 46ch;
}

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

@media (min-width: 560px) {
  .page-about .hero__facts { grid-template-columns: repeat(4, minmax(0, 1fr)); }
}

.page-about .hero__fact {
  background: var(--panel);
  border: 1px solid var(--rail);
  border-radius: var(--r-md);
  padding: 12px 14px;
}

.page-about .hero__fact dt {
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--ink-dim);
}

.page-about .hero__fact dd {
  margin: 6px 0 0;
  font-size: 22px;
  color: var(--amber);
  font-variant-numeric: tabular-nums;
}

/* ---------- 通用章节 ---------- */

.page-about .sec {
  padding: 48px 0;
  border-bottom: 1px solid var(--rail);
}

.page-about .sec:last-of-type { border-bottom: 0; }

@media (min-width: 768px) {
  .page-about .sec { padding: 72px 0; }
}

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

.page-about .sec__title {
  margin: 10px 0 0;
  font-family: var(--f-display);
  font-weight: 800;
  font-size: clamp(24px, 3.4vw, 40px);
  line-height: 1.1;
  letter-spacing: -0.02em;
  color: var(--ink);
}

.page-about .sec__lead {
  margin: 14px 0 0;
  font-size: var(--fs-body);
  line-height: 1.75;
  color: var(--ink-dim);
}

/* ---------- 图形 ---------- */

.page-about .about-figure {
  margin: 0;
  border-radius: var(--r-lg);
  overflow: hidden;
  background: var(--panel);
  border: 1px solid var(--rail);
}

.page-about .about-figure img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  object-fit: cover;
  background: var(--cyan-deep);
}

.page-about .about-figure figcaption {
  padding: 10px 14px 12px;
  font-size: 12px;
  line-height: 1.6;
  color: var(--ink-dim);
  border-top: 1px solid var(--rail);
}

.page-about .about-figure--wide { margin: 28px 0 34px; }
.page-about .about-figure--mid { margin: 24px 0 0; }
.page-about .about-figure--tall { margin: 0; }

@media (min-width: 860px) {
  .page-about .about-figure--wide { max-width: 860px; }
}

/* ---------- 时间线 ---------- */

.page-about .tl {
  display: grid;
  gap: var(--gutter);
}

@media (min-width: 880px) {
  .page-about .tl {
    grid-template-columns: var(--about-rail) minmax(0, 1fr);
    align-items: start;
  }
}

.page-about .tl__rail {
  position: relative;
  display: flex;
  gap: 6px;
  margin: 0;
  padding: 0 0 6px;
  list-style: none;
  overflow-x: auto;
  scroll-snap-type: x mandatory;
  -webkit-overflow-scrolling: touch;
}

.page-about .tl__rail::-webkit-scrollbar { height: 4px; }
.page-about .tl__rail::-webkit-scrollbar-thumb {
  background: var(--rail);
  border-radius: var(--r-pill);
}

@media (min-width: 880px) {
  .page-about .tl__rail {
    flex-direction: column;
    gap: 0;
    overflow: visible;
    padding: 0;
  }
  .page-about .tl__rail::before {
    content: "";
    position: absolute;
    left: 10px;
    top: 18px;
    bottom: 18px;
    width: 1px;
    background: var(--rail);
  }
}

.page-about .tl__item {
  flex: 0 0 auto;
  scroll-snap-align: start;
}

@media (min-width: 880px) {
  .page-about .tl__item { width: 100%; }
}

.page-about .tl__node {
  display: flex;
  align-items: center;
  gap: 10px;
  width: 100%;
  padding: 10px 14px;
  background: var(--panel);
  border: 1px solid var(--rail);
  border-radius: var(--r-pill);
  font: inherit;
  color: var(--ink-dim);
  text-align: left;
  cursor: pointer;
  transition: color var(--t-fast) var(--ease), border-color var(--t-fast) var(--ease), background var(--t-fast) var(--ease);
}

@media (min-width: 880px) {
  .page-about .tl__node {
    background: transparent;
    border-color: transparent;
    border-radius: var(--r-md);
    padding: 10px 12px 10px 0;
    align-items: flex-start;
  }
}

.page-about .tl__node:hover { color: var(--ink); }

.page-about .tl__node[aria-selected="true"] {
  color: var(--ink);
  border-color: var(--cyan);
  background: var(--panel-2);
}

@media (min-width: 880px) {
  .page-about .tl__node[aria-selected="true"] {
    background: transparent;
    border-color: transparent;
  }
}

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

.page-about .tl__dot {
  flex: 0 0 auto;
  width: 22px;
  height: 22px;
  border-radius: 50%;
  border: 1px solid var(--rail);
  background: var(--void);
  position: relative;
  display: none;
}

@media (min-width: 880px) {
  .page-about .tl__dot { display: block; margin-top: 2px; }
}

.page-about .tl__node[aria-selected="true"] .tl__dot {
  border-color: var(--cyan);
  background: var(--cyan-deep);
  box-shadow: 0 0 0 4px rgba(0, 229, 208, 0.12);
}

.page-about .tl__meta {
  display: flex;
  flex-direction: column;
  gap: 2px;
  min-width: 0;
}

.page-about .tl__ver {
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--cyan);
  text-transform: uppercase;
}

.page-about .tl__name {
  font-size: 14px;
  line-height: 1.4;
  white-space: nowrap;
}

@media (min-width: 880px) {
  .page-about .tl__name { white-space: normal; }
}

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

.page-about .tl__panel {
  background: var(--panel);
  border: 1px solid var(--rail);
  border-left: 2px solid var(--cyan);
  border-radius: var(--r-lg);
  padding: 22px 20px;
}

.page-about .tl__panel[hidden] { display: none; }

@media (min-width: 768px) {
  .page-about .tl__panel { padding: 30px 32px; }
}

.page-about .tl__tag {
  margin: 0;
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--amber);
}

.page-about .tl__head {
  margin: 10px 0 12px;
  font-family: var(--f-display);
  font-weight: 800;
  font-size: 20px;
  line-height: 1.35;
  color: var(--ink);
}

.page-about .tl__text {
  margin: 0;
  max-width: 60ch;
  font-size: var(--fs-body);
  line-height: 1.75;
  color: var(--ink-dim);
}

/* ---------- 栏目树 ---------- */

.page-about .tree {
  margin-top: 30px;
}

.page-about .tree__root {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  margin: 0 0 20px;
  padding: 10px 18px;
  border-radius: var(--r-pill);
  background: var(--cyan-deep);
  border: 1px solid var(--cyan-edge);
  color: var(--ink);
  font-size: 14px;
}

.page-about .tree__root .mono {
  font-size: 11px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--cyan);
}

.page-about .tree__branches {
  display: grid;
  gap: var(--gap);
}

@media (min-width: 780px) {
  .page-about .tree__branches { grid-template-columns: 7fr 5fr; }
}

.page-about .tree__branch-head {
  margin: 0 0 8px;
  font-size: 12px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--ink-dim);
  font-weight: 500;
}

.page-about .tree__leaves {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 6px;
  align-content: start;
}

.page-about .tree__leaves li {
  display: grid;
  gap: 4px;
  padding: 12px 16px;
  background: var(--panel);
  border: 1px solid var(--rail);
  border-left: 2px solid transparent;
  border-radius: var(--r-md);
  transition: border-left-color var(--t-fast) var(--ease), background var(--t-fast) var(--ease);
}

.page-about .tree__leaves li:hover,
.page-about .tree__leaves li:focus-within {
  border-left-color: var(--cyan);
  background: var(--panel-2);
}

.page-about .tree__leaves a {
  color: var(--ink);
  text-decoration: none;
  font-size: 15px;
  font-weight: 500;
}

.page-about .tree__leaves a:hover { color: var(--cyan); }

.page-about .tree__leaves a:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 2px;
  border-radius: 4px;
}

.page-about .tree__leaves span {
  font-size: 13px;
  line-height: 1.6;
  color: var(--ink-dim);
}

.page-about .tree__leaves--legal li { border-left-color: rgba(255, 181, 71, 0.4); }

.page-about .tree__notes {
  display: grid;
  gap: var(--gap);
  margin-top: 22px;
}

@media (min-width: 780px) {
  .page-about .tree__notes { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

.page-about .tree__note {
  padding: 18px 20px;
  border-radius: var(--r-lg);
  background: var(--panel-2);
  border: 1px solid var(--rail);
}

.page-about .tree__note-head {
  margin: 0 0 8px;
  font-size: 15px;
  font-weight: 600;
  color: var(--amber);
}

.page-about .tree__note-text {
  margin: 0;
  font-size: 14px;
  line-height: 1.75;
  color: var(--ink-dim);
}

/* ---------- 治理流程 ---------- */

.page-about .flow {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin: 30px 0 0;
  padding: 0;
}

.page-about .flow__step {
  flex: 1 1 132px;
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 12px 18px;
  border-radius: var(--r-pill);
  background: var(--cyan-deep);
  border: 1px solid var(--cyan-edge);
}

.page-about .flow__num {
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--cyan);
}

.page-about .flow__name {
  font-size: 14px;
  color: var(--ink);
}

.page-about .gov {
  display: grid;
  gap: var(--gutter);
  margin-top: 26px;
}

@media (min-width: 860px) {
  .page-about .gov {
    grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
    align-items: start;
    gap: 32px;
  }
}

.page-about .gov__text {
  display: grid;
  gap: 6px;
}

.page-about .gov__item {
  padding: 16px 18px;
  background: var(--panel);
  border: 1px solid var(--rail);
  border-radius: var(--r-md);
}

.page-about .gov__key {
  margin: 0 0 6px;
  font-size: 12px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--violet);
}

.page-about .gov__val {
  margin: 0;
  font-size: 14px;
  line-height: 1.75;
  color: var(--ink-dim);
}

/* ---------- 团队 ---------- */

.page-about .roles {
  list-style: none;
  margin: 30px 0 0;
  padding: 0;
  display: grid;
  gap: 6px;
}

.page-about .roles__row {
  display: grid;
  grid-template-columns: 44px 1fr;
  grid-template-areas:
    "n k"
    "n d";
  gap: 4px 14px;
  align-items: center;
  padding: 16px 18px;
  background: var(--panel);
  border: 1px solid var(--rail);
  border-radius: var(--r-md);
  transition: border-color var(--t-fast) var(--ease);
}

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

@media (min-width: 780px) {
  .page-about .roles__row {
    grid-template-columns: 72px 180px 1fr;
    grid-template-areas: "n k d";
    gap: 24px;
    padding: 18px 22px;
  }
}

.page-about .roles__n {
  grid-area: n;
  font-size: clamp(26px, 3.4vw, 40px);
  font-weight: 700;
  line-height: 1;
  color: var(--amber);
  font-variant-numeric: tabular-nums;
}

.page-about .roles__k {
  grid-area: k;
  font-size: 16px;
  font-weight: 600;
  color: var(--ink);
}

.page-about .roles__d {
  grid-area: d;
  font-size: 14px;
  line-height: 1.7;
  color: var(--ink-dim);
}

/* ---------- 地域 ---------- */

.page-about .regions {
  display: grid;
  gap: var(--gutter);
  margin-top: 30px;
}

@media (min-width: 860px) {
  .page-about .regions {
    grid-template-columns: minmax(0, 4fr) minmax(0, 7fr);
    align-items: start;
    gap: 32px;
  }
  .page-about .about-figure--tall { max-width: 340px; }
}

.page-about .regions__text p {
  margin: 0 0 14px;
  font-size: var(--fs-body);
  line-height: 1.75;
  color: var(--ink-dim);
  max-width: 62ch;
}

.page-about .regions__list {
  list-style: none;
  margin: 20px 0 0;
  padding: 0;
  display: grid;
  gap: 6px;
}

.page-about .regions__list li {
  position: relative;
  padding: 12px 16px 12px 34px;
  background: var(--panel);
  border: 1px solid var(--rail);
  border-radius: var(--r-md);
  font-size: 14px;
  line-height: 1.65;
  color: var(--ink-dim);
}

.page-about .regions__list li::before {
  content: "";
  position: absolute;
  left: 16px;
  top: 20px;
  width: 8px;
  height: 8px;
  border-radius: 2px;
  background: var(--cyan);
}

/* ---------- 收尾协作 ---------- */

.page-about .sec--tail { padding-bottom: 64px; }

.page-about .tail {
  max-width: 62ch;
  margin-top: 26px;
}

.page-about .tail__lead {
  margin: 0 0 22px;
  font-size: var(--fs-body);
  line-height: 1.75;
  color: var(--ink-dim);
}

.page-about .tail__steps {
  list-style: none;
  margin: 0;
  padding: 0;
  counter-reset: tailstep;
}

.page-about .tail__steps li {
  display: grid;
  grid-template-columns: 28px 1fr;
  gap: 14px;
  align-items: baseline;
  padding: 13px 0;
  border-bottom: 1px solid var(--rail);
  font-size: 14px;
  line-height: 1.7;
  color: var(--ink-dim);
}

.page-about .tail__steps li:first-child { border-top: 1px solid var(--rail); }

.page-about .tail__steps .mono {
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--amber);
}

.page-about .tail__note {
  margin: 24px 0 0;
  padding: 16px 18px;
  border-radius: var(--r-md);
  background: var(--cyan-deep);
  border: 1px solid var(--cyan-edge);
  font-size: 14px;
  line-height: 1.75;
  color: var(--ink);
}

/* ---------- 窄屏兜底 ---------- */

@media (max-width: 420px) {
  .page-about .about-wrap { padding: 0 14px; }
  .page-about .hero__title { font-size: 30px; }
  .page-about .roles__row { grid-template-columns: 36px 1fr; }
  .page-about .flow__step { flex: 1 1 100%; }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .tl__node,
  .page-about .tree__leaves li,
  .page-about .roles__row {
    transition: none;
  }
}
</main>