.page-about {
  --about-notch: polygon(0 0, 100% 3.4%, 100% 100%, 0 96.6%);
  background: var(--bone);
  color: var(--ink);
  font-family: var(--font-sans);
  overflow-x: hidden;
}

/* ---------- 面包屑 ---------- */
.page-about .breadcrumbs { padding-top: clamp(8px, 2vw, 18px); }
.page-about .crumb-list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  margin: 0;
  padding: 0;
  list-style: none;
  font-size: 13px;
  letter-spacing: .05em;
}
.page-about .crumb,
.page-about .crumb-sep { color: var(--bone-70); }
.page-about .crumb a {
  color: var(--bone-70);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color .2s var(--ease), border-color .2s var(--ease);
}
.page-about .crumb a:hover,
.page-about .crumb a:focus-visible {
  color: var(--gold);
  border-bottom-color: var(--gold);
}
.page-about .crumb[aria-current="page"] { color: var(--gold); }

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  padding-bottom: clamp(34px, 6vw, 70px);
  background:
    radial-gradient(130% 82% at 86% 0%, rgba(242, 184, 75, .20), transparent 58%),
    linear-gradient(158deg, var(--night) 0%, var(--table-green) 56%, var(--moss) 100%);
  color: var(--bone);
  border-bottom-left-radius: 8px;
  border-bottom-right-radius: 44px;
  overflow: hidden;
}
.page-about .about-hero::after {
  content: "";
  position: absolute;
  right: -80px;
  bottom: -110px;
  width: 300px;
  height: 300px;
  background: radial-gradient(circle, rgba(224, 138, 46, .30), transparent 70%);
  pointer-events: none;
}
.page-about .about-hero .shell { position: relative; z-index: 1; }

.page-about .about-hero-grid {
  display: grid;
  gap: clamp(20px, 3.6vw, 42px);
  align-items: center;
  margin-top: clamp(18px, 3vw, 34px);
}
.page-about .about-hero .eyebrow { color: var(--gold); }
.page-about .about-hero h1 {
  margin: 10px 0 16px;
  font-size: clamp(30px, 6.4vw, 62px);
  font-weight: 900;
  line-height: 1.06;
  letter-spacing: -.02em;
}
.page-about .about-hero .lede {
  margin: 0;
  max-width: 34em;
  color: var(--bone-70);
  font-size: 16px;
  line-height: 1.75;
}
.page-about .about-hero-actions {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 16px;
  margin-top: clamp(18px, 3vw, 28px);
}
.page-about .about-hero-figure {
  margin: 0;
  border-radius: 4px 30px 4px 30px;
  overflow: hidden;
  box-shadow: var(--shadow-lift);
}
.page-about .about-hero-figure img {
  display: block;
  width: 100%;
  height: auto;
  max-width: 100%;
  object-fit: cover;
}

.page-about .about-stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 10px;
  margin: clamp(26px, 4vw, 46px) 0 0;
  padding: 0;
  list-style: none;
}
.page-about .about-stats .stat {
  padding: 14px 16px 16px;
  background: var(--bone-14);
  border: 1px solid rgba(246, 241, 230, .12);
  border-radius: 14px;
}
.page-about .about-stats .stat-num {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(26px, 4.4vw, 38px);
  font-weight: 700;
  line-height: 1.08;
  letter-spacing: -.02em;
  color: var(--gold);
  font-variant-numeric: tabular-nums slashed-zero;
}
.page-about .about-unit {
  margin-left: 4px;
  font-size: .48em;
  color: var(--bone-70);
}
.page-about .about-stats .stat-label {
  display: block;
  margin-top: 6px;
  font-size: 12px;
  letter-spacing: .08em;
  color: var(--bone-70);
}

/* ---------- 节奏章节 ---------- */
.page-about .about-rhythm { padding-block: clamp(42px, 7vw, 84px); }
.page-about .about-rhythm-grid {
  display: grid;
  gap: clamp(24px, 4vw, 52px);
  align-items: center;
}
.page-about .about-rhythm .eyebrow { color: var(--vermilion); }
.page-about .about-rhythm .section-title { margin: 10px 0 18px; }
.page-about .about-rhythm-figure {
  padding: clamp(18px, 3vw, 30px);
  background: linear-gradient(150deg, var(--stroke-base, var(--stone)), var(--bone));
  border-radius: 4px 26px 4px 26px;
}
.page-about .about-chart {
  display: block;
  width: 100%;
  height: auto;
}
.page-about .chart-axis { stroke: rgba(108, 119, 112, .35); stroke-width: 1.5; stroke-dasharray: 4 5; }
.page-about .chart-line {
  fill: none;
  stroke: var(--chip);
  stroke-width: 3;
  stroke-linecap: round;
  stroke-linejoin: round;
}
.page-about .chart-dot { fill: var(--table-green); }
.page-about .chart-dot--end { fill: var(--gold); }
.page-about .chart-label {
  font-family: var(--font-mono);
  font-size: 13px;
  fill: var(--ash);
}
.page-about .chart-label--end { fill: var(--table-green); font-weight: 700; }
.page-about .about-chart-note {
  margin: 14px 0 0;
  font-size: 13px;
  letter-spacing: .04em;
  color: var(--ash);
}

/* ---------- 版本演进 ---------- */
.page-about .about-timeline {
  padding-block: clamp(42px, 7vw, 84px);
  background: linear-gradient(180deg, var(--bone) 0%, var(--stone) 42%, var(--bone) 100%);
}
.page-about .about-timeline .eyebrow { color: var(--moss); }
.page-about .about-timeline .section-title { margin: 10px 0 12px; }
.page-about .about-timeline-band {
  margin-top: clamp(24px, 4vw, 44px);
  padding-block: 6px;
}
.page-about .about-timeline-band .band-track {
  display: flex;
  gap: var(--gap);
  padding: 6px clamp(1.2rem, 4vw, 3rem) 26px;
  overflow-x: auto;
  scroll-snap-type: x mandatory;
  -webkit-overflow-scrolling: touch;
}
.page-about .about-stage {
  flex: 0 0 min(80vw, 342px);
  scroll-snap-align: start;
  display: flex;
  flex-direction: column;
  padding: clamp(22px, 3vw, 30px) clamp(18px, 2.6vw, 26px) clamp(26px, 3.6vw, 34px);
  background: var(--bone);
  border: 1px solid var(--stone);
  clip-path: var(--about-notch);
}
.page-about .about-stage--2 { background: var(--stone); }
.page-about .about-stage--3 {
  background: linear-gradient(160deg, var(--table-green), var(--night));
  border-color: var(--chip);
  color: var(--bone);
}
.page-about .about-stage-num {
  margin: 0;
  font-size: 12px;
  letter-spacing: .14em;
  color: var(--chip);
}
.page-about .about-stage-title {
  margin: 10px 0 10px;
  font-size: 20px;
  line-height: 1.35;
  font-weight: 700;
  letter-spacing: -.01em;
}
.page-about .about-stage--3 .about-stage-title { color: var(--bone); }
.page-about .about-stage-text {
  margin: 0;
  font-size: 15px;
  line-height: 1.72;
  color: var(--ink);
  opacity: .86;
}
.page-about .about-stage--3 .about-stage-text { color: var(--bone-70); opacity: 1; }
.page-about .about-stage-list {
  margin: 16px 0 0;
  padding: 0;
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}
.page-about .about-stage-list li {
  padding: 5px 11px;
  font-size: 12px;
  letter-spacing: .04em;
  border: 1px solid var(--chip-16);
  border-radius: var(--radius-pill);
  background: var(--moss-12);
  color: var(--moss);
}
.page-about .about-stage--3 .about-stage-list li {
  background: rgba(224, 138, 46, .16);
  border-color: rgba(242, 184, 75, .38);
  color: var(--gold);
}

.page-about .about-era-foot {
  display: grid;
  gap: clamp(20px, 3.4vw, 40px);
  align-items: center;
  margin-top: clamp(22px, 4vw, 42px);
}
.page-about .about-era-figure {
  margin: 0;
  max-width: 420px;
  border-radius: 26px 4px 26px 4px;
  overflow: hidden;
}
.page-about .about-era-figure img {
  display: block;
  width: 100%;
  height: auto;
  max-width: 100%;
  object-fit: cover;
}
.page-about .about-era-figure .img-caption {
  margin: 10px 0 0;
  font-size: 13px;
  color: var(--ash);
}
.page-about .about-era-note-title {
  margin: 0 0 12px;
  font-size: 20px;
  font-weight: 700;
  letter-spacing: -.01em;
}
.page-about .about-era-note p {
  margin: 0 0 14px;
  max-width: 34em;
  font-size: 16px;
  line-height: 1.75;
}

/* ---------- 规则与结算 ---------- */
.page-about .about-rules { padding-block: clamp(44px, 7vw, 86px); }
.page-about .about-rules .eyebrow { color: var(--vermilion); }
.page-about .about-rules .section-title { margin: 10px 0 18px; }
.page-about .about-two-col {
  display: grid;
  gap: clamp(22px, 3.6vw, 48px);
}
.page-about .about-notes { display: grid; gap: 12px; }
.page-about .side-note {
  padding: 14px 18px;
  background: var(--stone);
  border-left: 3px solid var(--chip);
  border-radius: 3px 16px 16px 3px;
}
.page-about .side-note summary {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 12px;
  cursor: pointer;
  font-size: 15px;
  font-weight: 700;
  letter-spacing: -.005em;
  list-style: none;
}
.page-about .side-note summary::-webkit-details-marker { display: none; }
.page-about .side-note summary::after {
  content: "+";
  flex: none;
  font-family: var(--font-mono);
  font-size: 17px;
  color: var(--chip);
}
.page-about .side-note[open] summary::after { content: "–"; }
.page-about .side-note summary:focus-visible {
  outline: 2px solid var(--chip);
  outline-offset: 3px;
}
.page-about .side-note p {
  margin: 10px 0 0;
  font-size: 14px;
  line-height: 1.7;
  color: var(--ink);
  opacity: .82;
}

/* ---------- 区域适配 ---------- */
.page-about .about-region {
  padding-block: clamp(46px, 7vw, 90px);
  background:
    radial-gradient(120% 90% at 8% 0%, rgba(224, 138, 46, .18), transparent 56%),
    linear-gradient(150deg, var(--table-green) 0%, var(--night) 100%);
  color: var(--bone);
  border-top-right-radius: 40px;
  border-bottom-left-radius: 40px;
}
.page-about .about-region .eyebrow { color: var(--gold); }
.page-about .about-region .section-title {
  margin: 10px 0 12px;
  color: var(--bone);
}
.page-about .about-region .section-note { color: var(--bone-70); }
.page-about .about-region-grid {
  display: grid;
  gap: var(--gap);
  margin-top: clamp(24px, 4vw, 42px);
}
.page-about .about-region-tile {
  padding: clamp(18px, 2.6vw, 26px);
  background: rgba(246, 241, 230, .07);
  border: 1px solid rgba(246, 241, 230, .14);
  border-radius: 4px 20px 4px 20px;
}
.page-about .about-region-tile .tile-title {
  margin: 0 0 10px;
  font-size: 18px;
  font-weight: 700;
  color: var(--bone);
}
.page-about .about-region-tile .tile-meta {
  margin: 0;
  font-size: 14px;
  line-height: 1.72;
  color: var(--bone-70);
}
.page-about .about-region-foot {
  margin: clamp(22px, 3.4vw, 36px) 0 0;
  max-width: 34em;
  padding-left: 16px;
  border-left: 2px solid var(--chip);
  font-size: 14px;
  line-height: 1.7;
  color: var(--bone-70);
}

/* ---------- 服务通道 ---------- */
.page-about .about-service { padding-block: clamp(44px, 7vw, 86px); }
.page-about .about-service-grid {
  display: grid;
  gap: clamp(22px, 3.6vw, 46px);
  align-items: start;
}
.page-about .about-service-figure {
  margin: 0;
  border-radius: 30px 4px 30px 4px;
  overflow: hidden;
}
.page-about .about-service-figure img {
  display: block;
  width: 100%;
  height: auto;
  max-width: 100%;
  object-fit: cover;
}
.page-about .about-service .eyebrow { color: var(--moss); }
.page-about .about-service .section-title { margin: 10px 0 18px; }
.page-about .about-contact-list {
  margin: clamp(18px, 3vw, 28px) 0 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 2px;
}
.page-about .about-contact-list li {
  display: grid;
  gap: 4px;
  padding: 12px 0;
  border-bottom: 1px solid var(--stone);
}
.page-about .contact-key {
  font-size: 12px;
  letter-spacing: .1em;
  color: var(--ash);
}
.page-about .contact-val {
  font-size: 15px;
  line-height: 1.6;
  color: var(--ink);
  word-break: break-word;
}
.page-about .contact-val--mono {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums slashed-zero;
  letter-spacing: -.01em;
}
.page-about .about-service-link { display: inline-block; margin-top: 18px; }

/* ---------- 收尾 ---------- */
.page-about .about-cta-band {
  padding-block: clamp(30px, 5vw, 56px);
  background: var(--moss);
  border-top-right-radius: 36px;
  border-top-left-radius: 36px;
}
.page-about .about-cta-inner {
  display: grid;
  gap: clamp(18px, 3vw, 34px);
  align-items: center;
}
.page-about .about-cta-copy h2 {
  margin: 0 0 10px;
  font-size: clamp(22px, 3.4vw, 32px);
  line-height: 1.28;
  font-weight: 900;
  letter-spacing: -.02em;
  color: var(--bone);
}
.page-about .about-cta-copy p {
  margin: 0;
  max-width: 34em;
  font-size: 15px;
  line-height: 1.72;
  color: var(--bone-70);
}
.page-about .about-cta-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
}
.page-about .about-cta-actions .btn-line {
  border-color: rgba(246, 241, 230, .45);
  color: var(--bone);
}

/* ---------- 响应式 ---------- */
@media (min-width: 760px) {
  .page-about .about-stats { grid-template-columns: repeat(4, minmax(0, 1fr)); gap: var(--gap); }
  .page-about .about-stats .stat:nth-child(even) { transform: translateY(12px); }
  .page-about .about-region-grid { grid-template-columns: repeat(3, minmax(0, 1fr)); }
}

@media (min-width: 900px) {
  .page-about .about-hero-grid { grid-template-columns: 1.04fr .96fr; }
  .page-about .about-rhythm-grid { grid-template-columns: 1.1fr .9fr; }
  .page-about .about-two-col { grid-template-columns: minmax(0, 1.5fr) minmax(0, 1fr); align-items: start; }
  .page-about .about-era-foot { grid-template-columns: minmax(0, .85fr) minmax(0, 1.15fr); }
  .page-about .about-service-grid { grid-template-columns: minmax(0, 1fr) minmax(0, 1.15fr); }
  .page-about .about-cta-inner { grid-template-columns: minmax(0, 1.4fr) auto; }
}

@media (min-width: 1100px) {
  .page-about .about-timeline-band .band-track { padding-inline: max(1.2rem, calc((100vw - var(--shell)) / 2)); }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .crumb a,
  .page-about .about-stats .stat { transition: none; }
}

.page-about {
  --stroke-base: transparent;
}