.page-about {
  --about-rail: 168px;
  --about-cut: 18px;
  --bar: 0%;
  position: relative;
  overflow-x: clip;
  background: var(--ink);
  color: var(--text);
}

.page-about::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  background-image:
    repeating-linear-gradient(0deg, rgba(108, 126, 140, .06) 0 1px, transparent 1px 72px),
    repeating-linear-gradient(90deg, rgba(108, 126, 140, .06) 0 1px, transparent 1px 72px);
  -webkit-mask-image: linear-gradient(180deg, rgba(0, 0, 0, .9), rgba(0, 0, 0, .22) 42%, rgba(0, 0, 0, .7));
  mask-image: linear-gradient(180deg, rgba(0, 0, 0, .9), rgba(0, 0, 0, .22) 42%, rgba(0, 0, 0, .7));
}

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

/* ---------- 首屏 ---------- */

.page-about .about-hero {
  position: relative;
  padding: 92px 0 64px;
  border-bottom: 1px solid var(--line);
  overflow: hidden;
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  inset: -30% -12% auto -12%;
  height: 150%;
  z-index: 0;
  pointer-events: none;
  background:
    radial-gradient(58% 58% at 74% 0%, rgba(43, 240, 155, .13), transparent 66%),
    radial-gradient(52% 52% at 6% 18%, rgba(77, 166, 255, .11), transparent 62%),
    radial-gradient(40% 40% at 46% 92%, rgba(255, 138, 61, .07), transparent 70%);
}

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

.page-about .breadcrumbs {
  margin-bottom: 34px;
}

.page-about .about-title {
  margin: 20px 0 22px;
  font-family: var(--font-display);
  font-weight: 200;
  font-size: clamp(40px, 11vw, 96px);
  line-height: .98;
  letter-spacing: -.02em;
  color: var(--white);
}

.page-about .about-lede {
  max-width: 62ch;
  margin: 0;
  font-size: 17px;
  line-height: 1.8;
  color: var(--text);
}

.page-about .about-jump {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 10px;
  margin: 36px 0 0;
  padding: 0;
  list-style: none;
}

.page-about .about-jump a {
  display: inline-flex;
  align-items: center;
  min-height: 40px;
  padding: 8px 14px;
  border: 1px solid var(--line);
  background: rgba(16, 22, 27, .6);
  color: var(--text);
  font-size: 13px;
  letter-spacing: .03em;
  text-decoration: none;
  transition: border-color .18s var(--ease), color .18s var(--ease), transform .18s var(--ease);
}

.page-about .about-jump a:hover,
.page-about .about-jump a:focus-visible {
  border-color: var(--green);
  color: var(--white);
  transform: translateY(-2px);
}

/* ---------- 区块骨架 ---------- */

.page-about .about-block {
  padding: 76px 0;
}

.page-about .block-grid {
  display: grid;
  gap: 24px;
}

.page-about .block-rail {
  display: flex;
  align-items: baseline;
  gap: 12px;
}

.page-about .block-num {
  font-family: var(--font-mono);
  font-size: 30px;
  font-weight: 500;
  line-height: 1;
  color: var(--green);
  letter-spacing: -.02em;
}

.page-about .block-label {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .16em;
  text-transform: uppercase;
  color: var(--snow);
}

.page-about .block-title {
  margin: 0 0 20px;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(26px, 5.6vw, 46px);
  line-height: 1.06;
  letter-spacing: -.03em;
  color: var(--white);
}

.page-about .block-intro {
  max-width: 66ch;
  margin: 0 0 28px;
  font-size: 16px;
  line-height: 1.8;
  color: var(--text);
}

.page-about .block-intro strong {
  color: var(--white);
  font-weight: 600;
}

.page-about .block-main .prose p {
  max-width: 68ch;
  margin: 0 0 18px;
  font-size: 16px;
  line-height: 1.85;
}

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

/* ---------- 定位标签 ---------- */

.page-about .focus-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 30px 0 0;
  padding: 0;
  list-style: none;
}

.page-about .focus-tags .chip {
  border: 1px solid var(--line);
  background: var(--panel);
  color: var(--text);
}

/* ---------- 指标 ---------- */

.page-about .wide-figure {
  margin: 0 0 32px;
  border: 1px solid var(--line);
  background: var(--panel);
}

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

.page-about .metric-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 18px;
}

.page-about .metric {
  position: relative;
  padding: 26px 20px 24px;
  background: var(--panel);
  border: 1px solid var(--line);
  clip-path: polygon(0 0, calc(100% - var(--about-cut)) 0, 100% var(--about-cut), 100% 100%, 0 100%);
  transition: background .22s var(--ease), transform .22s var(--ease);
}

.page-about .metric:nth-child(even) {
  clip-path: polygon(0 0, 100% 0, 100% 100%, var(--about-cut) 100%, 0 calc(100% - var(--about-cut)));
}

.page-about .metric::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 42px;
  height: 3px;
  background: var(--green);
}

.page-about .metric:nth-child(even)::before {
  left: auto;
  right: 0;
  background: var(--blue);
}

.page-about .metric:hover,
.page-about .metric:focus-within {
  background: var(--panel-2);
  transform: translateY(-4px);
}

.page-about .metric-key {
  display: block;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: .12em;
  color: var(--snow);
  margin-bottom: 16px;
}

.page-about .metric-name {
  margin: 0 0 12px;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: 22px;
  line-height: 1.15;
  letter-spacing: -.02em;
  color: var(--white);
}

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

.page-about .term {
  position: relative;
  display: inline-block;
  border-bottom: 1px dashed rgba(43, 240, 155, .5);
  cursor: help;
  outline: none;
}

.page-about .term:focus-visible {
  border-bottom-color: var(--green);
  box-shadow: 0 0 0 2px rgba(43, 240, 155, .35);
}

.page-about .term-pop {
  position: absolute;
  left: 0;
  top: calc(100% + 10px);
  z-index: 6;
  width: min(260px, 74vw);
  padding: 12px 14px;
  background: #0C1217;
  border: 1px solid var(--green);
  color: var(--text);
  font-family: var(--font-body);
  font-size: 13px;
  font-weight: 400;
  line-height: 1.65;
  letter-spacing: 0;
  opacity: 0;
  visibility: hidden;
  transform: translateY(-6px);
  transition: opacity .18s var(--ease), transform .18s var(--ease), visibility .18s;
  pointer-events: none;
}

.page-about .term:hover .term-pop,
.page-about .term:focus-visible .term-pop,
.page-about .term.is-open .term-pop {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.page-about .metric-note {
  margin-top: 26px;
  padding: 20px 22px;
  background: var(--panel);
  border-left: 3px solid var(--orange);
}

.page-about .metric-note p {
  color: var(--text);
}

.page-about .metric-note strong {
  color: var(--white);
  font-weight: 600;
}

/* ---------- 数据来源 ---------- */

.page-about .data-split {
  display: grid;
  grid-template-columns: 1fr;
  gap: 26px;
}

.page-about .data-figure {
  margin: 0;
  border: 1px solid var(--line);
  background: var(--panel);
}

.page-about .data-points {
  margin: 24px 0 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 12px;
}

.page-about .data-points li {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 14px;
  line-height: 1.6;
  color: var(--white);
}

.page-about .dot {
  width: 9px;
  height: 9px;
  flex: 0 0 9px;
  background: var(--green);
  transform: rotate(45deg);
}

.page-about .dot--blue { background: var(--blue); }
.page-about .dot--orange { background: var(--orange); }

/* ---------- 团队 ---------- */

.page-about .team-bars {
  display: grid;
  gap: 28px;
}

.page-about .team-row {
  display: grid;
  gap: 10px;
}

.page-about .team-head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 16px;
}

.page-about .team-name {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: 17px;
  letter-spacing: -.01em;
  color: var(--white);
}

.page-about .team-count {
  font-family: var(--font-mono);
  font-size: 28px;
  font-weight: 700;
  line-height: 1;
  color: var(--green);
}

.page-about .team-bar {
  position: relative;
  height: 6px;
  background: var(--panel-2);
  overflow: hidden;
}

.page-about .team-bar::after {
  content: "";
  position: absolute;
  inset: 0 auto 0 0;
  width: var(--bar, 0%);
  background: linear-gradient(90deg, var(--green), rgba(43, 240, 155, .25));
}

.page-about .team-bar--blue::after {
  background: linear-gradient(90deg, var(--blue), rgba(77, 166, 255, .22));
}

.page-about .team-bar--orange::after {
  background: linear-gradient(90deg, var(--orange), rgba(255, 138, 61, .22));
}

.page-about .team-duty {
  margin: 0;
  max-width: 64ch;
  font-size: 14px;
  line-height: 1.75;
  color: var(--text);
}

/* ---------- 时间线 ---------- */

.page-about .era-banner {
  position: relative;
  margin: 0 0 34px;
  border: 1px solid var(--line);
  background: var(--panel);
}

.page-about .era-banner::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(90deg, rgba(7, 9, 11, .82), rgba(7, 9, 11, .18) 45%, rgba(7, 9, 11, .82));
  pointer-events: none;
}

.page-about .era-list {
  position: relative;
  margin: 0;
  padding: 0 0 0 24px;
  list-style: none;
}

.page-about .era-list::before {
  content: "";
  position: absolute;
  left: 5px;
  top: 8px;
  bottom: 8px;
  width: 1px;
  background: linear-gradient(180deg, var(--green), var(--blue) 55%, var(--line));
}

.page-about .era-item {
  position: relative;
  margin-bottom: 14px;
}

.page-about .era-item::before {
  content: "";
  position: absolute;
  left: -24px;
  top: 20px;
  width: 11px;
  height: 11px;
  background: var(--ink);
  border: 2px solid var(--green);
  transform: rotate(45deg);
}

.page-about .era-item:last-child::before {
  border-color: var(--blue);
  box-shadow: 0 0 0 4px rgba(77, 166, 255, .16);
}

.page-about .era-fold {
  border: 1px solid var(--line);
  background: var(--panel);
  transition: border-color .18s var(--ease);
}

.page-about .era-fold:hover,
.page-about .era-fold[open] {
  border-color: rgba(43, 240, 155, .45);
}

.page-about .era-summary {
  display: grid;
  grid-template-columns: 1fr;
  gap: 6px;
  padding: 18px 44px 18px 20px;
  cursor: pointer;
  list-style: none;
  position: relative;
}

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

.page-about .era-summary::after {
  content: "+";
  position: absolute;
  right: 18px;
  top: 18px;
  font-family: var(--font-mono);
  font-size: 18px;
  line-height: 1;
  color: var(--green);
  transition: transform .18s var(--ease);
}

.page-about .era-fold[open] .era-summary::after {
  content: "–";
}

.page-about .era-tick {
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: .14em;
  color: var(--snow);
  text-transform: uppercase;
}

.page-about .era-title {
  font-family: var(--font-display);
  font-weight: 900;
  font-size: 17px;
  line-height: 1.3;
  letter-spacing: -.01em;
  color: var(--white);
}

.page-about .era-fold .fold-body {
  padding: 0 20px 20px;
}

.page-about .era-fold .fold-body p {
  margin: 0;
  max-width: 66ch;
  font-size: 14px;
  line-height: 1.8;
  color: var(--text);
}

/* ---------- 费用 ---------- */

.page-about .fee-ladder {
  display: grid;
  gap: 14px;
  margin-bottom: 36px;
}

.page-about .fee-step {
  position: relative;
  padding: 22px 20px 20px;
  background: var(--panel);
  border: 1px solid var(--line);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 14px), calc(100% - 14px) 100%, 0 100%);
  outline: none;
  transition: border-color .2s var(--ease), background .2s var(--ease), transform .2s var(--ease);
}

.page-about .fee-step::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: 0;
  width: 100%;
  height: 3px;
  background: linear-gradient(90deg, var(--green), rgba(43, 240, 155, 0));
  opacity: .5;
  transition: opacity .2s var(--ease);
}

.page-about .fee-step:nth-child(2)::after {
  background: linear-gradient(90deg, var(--blue), rgba(77, 166, 255, 0));
}

.page-about .fee-step:nth-child(3)::after {
  background: linear-gradient(90deg, var(--orange), rgba(255, 138, 61, 0));
}

.page-about .fee-step:hover,
.page-about .fee-step:focus-visible {
  border-color: rgba(43, 240, 155, .5);
  background: var(--panel-2);
  transform: translateX(6px);
}

.page-about .fee-step:hover::after,
.page-about .fee-step:focus-visible::after {
  opacity: 1;
}

.page-about .fee-step-head {
  display: flex;
  align-items: baseline;
  gap: 12px;
  margin-bottom: 10px;
}

.page-about .fee-step-index {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .12em;
  color: var(--snow);
}

.page-about .fee-step-name {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: 22px;
  letter-spacing: -.02em;
  color: var(--white);
}

.page-about .fee-step-scope {
  margin: 0 0 10px;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: .04em;
  color: var(--green);
}

.page-about .fee-step:nth-child(2) .fee-step-scope { color: var(--blue); }
.page-about .fee-step:nth-child(3) .fee-step-scope { color: var(--orange); }

.page-about .fee-step-detail {
  margin: 0;
  max-width: 62ch;
  font-size: 14px;
  line-height: 1.75;
  color: var(--text);
  transition: color .2s var(--ease);
}

.page-about .fee-step:hover .fee-step-detail,
.page-about .fee-step:focus-visible .fee-step-detail {
  color: var(--white);
}

.page-about .fee-range {
  padding: 26px 22px;
  background: var(--panel-2);
  border: 1px solid var(--line);
}

.page-about .fee-range-num {
  display: flex;
  align-items: baseline;
  flex-wrap: wrap;
  gap: 8px;
  margin: 0 0 14px;
  font-family: var(--font-mono);
}

.page-about .fee-range-num .num {
  font-size: clamp(40px, 10vw, 72px);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -.03em;
  color: var(--white);
}

.page-about .fee-dash {
  font-size: clamp(28px, 6vw, 44px);
  color: var(--orange);
  line-height: 1;
}

.page-about .fee-unit {
  font-size: 13px;
  letter-spacing: .12em;
  text-transform: uppercase;
  color: var(--snow);
}

.page-about .fee-range-note {
  margin: 0;
  max-width: 64ch;
  font-size: 15px;
  line-height: 1.8;
  color: var(--text);
}

.page-about .fee-range-note strong {
  color: var(--white);
  font-weight: 600;
}

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

.page-about .fee-links {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 22px;
}

/* ---------- 交付与反馈 ---------- */

.page-about .care-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 16px;
}

.page-about .care-card {
  padding: 22px 20px 20px;
  background: var(--panel);
  border: 1px solid var(--line);
  border-top: 3px solid var(--green);
}

.page-about .care-card:nth-child(2) { border-top-color: var(--blue); }
.page-about .care-card:nth-child(3) { border-top-color: var(--orange); }
.page-about .care-card:nth-child(4) { border-top-color: var(--snow); }

.page-about .care-value {
  display: flex;
  align-items: baseline;
  gap: 8px;
  margin: 0 0 14px;
  font-family: var(--font-mono);
}

.page-about .care-value .num {
  font-size: clamp(34px, 8vw, 48px);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -.03em;
  color: var(--white);
}

.page-about .care-unit {
  font-size: 13px;
  letter-spacing: .1em;
  color: var(--snow);
}

.page-about .care-label {
  margin: 0 0 8px;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: 16px;
  letter-spacing: -.01em;
  color: var(--white);
}

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

.page-about .care-tail {
  margin: 30px 0 0;
  font-size: 15px;
  line-height: 1.85;
  color: var(--text);
  max-width: 70ch;
}

.page-about .care-tail a {
  color: var(--blue);
  text-decoration: none;
  border-bottom: 1px solid rgba(77, 166, 255, .4);
}

.page-about .care-tail a:hover,
.page-about .care-tail a:focus-visible {
  color: var(--white);
  border-bottom-color: var(--white);
}

/* ---------- 平板 ---------- */

@media (min-width: 700px) {
  .page-about .about-hero {
    padding: 118px 0 82px;
  }

  .page-about .about-block {
    padding: 96px 0;
  }

  .page-about .block-grid {
    grid-template-columns: 132px minmax(0, 1fr);
    gap: 32px;
  }

  .page-about .block-rail {
    flex-direction: column;
    gap: 8px;
    align-self: start;
    position: sticky;
    top: calc(var(--header-h) + 42px);
  }

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

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

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

  .page-about .fee-ladder {
    gap: 16px;
  }

  .page-about .era-summary {
    grid-template-columns: 108px minmax(0, 1fr);
    align-items: baseline;
    gap: 16px;
  }
}

/* ---------- 桌面 ---------- */

@media (min-width: 1024px) {
  .page-about .about-hero {
    padding: 136px 0 96px;
  }

  .page-about .about-block {
    padding: 120px 0;
  }

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

  .page-about .block-num {
    font-size: 34px;
  }

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

  .page-about .metric {
    padding: 30px 22px 26px;
  }

  .page-about .data-split {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, .95fr);
    gap: 40px;
    align-items: start;
  }

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

  .page-about .fee-step:nth-child(2) {
    margin-left: 6%;
  }

  .page-about .fee-step:nth-child(3) {
    margin-left: 12%;
  }

  .page-about .era-banner {
    margin-bottom: 44px;
  }
}

/* ---------- 动效降级 ---------- */

@media (prefers-reduced-motion: reduce) {
  .page-about .metric,
  .page-about .fee-step,
  .page-about .about-jump a {
    transition: none;
  }

  .page-about .metric:hover,
  .page-about .metric:focus-within {
    transform: none;
  }

  .page-about .fee-step:hover,
  .page-about .fee-step:focus-visible {
    transform: none;
  }
}