.page-about {
  --about-rule: rgba(43, 48, 52, 0.16);
  --about-rule-night: rgba(201, 194, 180, 0.22);
  --about-rule-warm: rgba(251, 247, 238, 0.24);
  background: var(--warm);
  color: var(--ink-green);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  background: var(--night);
  color: var(--warm);
  padding-block: clamp(1.25rem, 3.5vw, 2.25rem) clamp(2.25rem, 5vw, 4rem);
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image: linear-gradient(to right, var(--line-night) 1px, transparent 1px);
  background-size: 25% 100%;
  opacity: 0.7;
}

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

.page-about .about-hero .crumb-link {
  color: var(--warm-70);
}

.page-about .about-hero .crumb-current {
  color: var(--warm);
}

.page-about .about-hero-grid {
  display: grid;
  gap: clamp(1.5rem, 3vw, 2.5rem);
  margin-top: clamp(1.5rem, 4vw, 2.75rem);
}

.page-about .about-hero-copy h1 {
  margin: 0.6rem 0 0;
  font-family: var(--font-head);
  font-size: clamp(2.3rem, 7vw, 4.4rem);
  font-weight: 800;
  line-height: 1.02;
  letter-spacing: -0.01em;
  color: var(--warm);
}

.page-about .about-hero-copy .lede {
  margin-top: 1.1rem;
  max-width: 36rem;
  color: var(--warm-80);
  font-size: clamp(1rem, 1.6vw, 1.125rem);
  line-height: 1.8;
}

.page-about .about-hero .eyebrow {
  color: var(--orange);
}

.page-about .about-hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.7rem;
  margin-top: 1.6rem;
}

.page-about .about-hero-media {
  margin: 0;
  border-radius: var(--r-lg);
  overflow: hidden;
  border: 1px solid var(--line-night-strong);
}

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

.page-about .about-facts {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: clamp(1.75rem, 4vw, 2.75rem) 0 0;
  padding: 0;
  background: var(--line-night-strong);
  border-radius: var(--r-md);
  overflow: hidden;
}

.page-about .about-fact {
  background: var(--night);
  padding: 0.95rem 1.05rem;
}

.page-about .about-fact dt {
  margin: 0;
  font-family: var(--font-data);
  font-size: 0.7rem;
  letter-spacing: 0.14em;
  color: var(--warm-55);
}

.page-about .about-fact dd {
  margin: 0.35rem 0 0;
  font-family: var(--font-head);
  font-size: clamp(1.55rem, 3.2vw, 2.2rem);
  font-weight: 700;
  line-height: 1;
  color: var(--warm);
}

/* ---------- 章节通用 ---------- */
.page-about .about-section {
  padding-block: clamp(2.5rem, 6vw, 5rem);
}

.page-about .about-head {
  max-width: 46rem;
  margin-bottom: clamp(1.5rem, 3vw, 2.5rem);
}

.page-about .about-head--flush {
  margin-bottom: 0;
}

.page-about .about-head .section-title {
  margin: 0.5rem 0 0;
}

.page-about .about-head .lede {
  margin-top: 0.9rem;
  font-size: clamp(0.98rem, 1.5vw, 1.08rem);
  line-height: 1.85;
}

.page-about .about-copy {
  margin: 0;
  line-height: 1.85;
  color: var(--rock);
}

/* ---------- 01 入口 ---------- */
.page-about .about-origin {
  background: var(--warm);
}

.page-about .about-origin-grid {
  display: grid;
  gap: clamp(1.5rem, 3vw, 2.5rem);
}

.page-about .about-route-list {
  list-style: none;
  margin: 1.6rem 0 0;
  padding: 0;
}

.page-about .about-route-list li {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 0.9rem;
  padding: 1.1rem 0;
  border-top: 1px solid var(--about-rule);
}

.page-about .about-route-list li:last-child {
  border-bottom: 1px solid var(--about-rule);
}

.page-about .about-route-list h3 {
  margin: 0;
  font-family: var(--font-head);
  font-size: 1.25rem;
  font-weight: 700;
  letter-spacing: 0.01em;
  color: var(--ink-green);
}

.page-about .about-route-list p {
  margin: 0.4rem 0 0;
  font-size: 0.96rem;
  line-height: 1.8;
  color: var(--rock);
}

.page-about .about-card-panel {
  background: var(--mist);
  border-radius: var(--r-lg);
  padding: clamp(1.25rem, 3vw, 1.85rem);
  color: var(--ink-green);
}

.page-about .about-card-coord {
  margin: 0;
  font-family: var(--font-data);
  font-size: 0.72rem;
  letter-spacing: 0.16em;
  color: var(--moss);
}

.page-about .about-card-panel h3 {
  margin: 0.5rem 0 0;
  font-family: var(--font-head);
  font-size: clamp(1.25rem, 2.4vw, 1.6rem);
  font-weight: 700;
  line-height: 1.2;
  color: var(--ink-green);
}

.page-about .about-card-panel p {
  margin: 0.75rem 0 0;
  font-size: 0.95rem;
  line-height: 1.8;
  color: var(--rock);
}

.page-about .about-card-list {
  list-style: none;
  margin: 1.1rem 0 0;
  padding: 0;
  display: grid;
  gap: 0.6rem;
}

.page-about .about-card-list li {
  position: relative;
  padding-left: 1.15rem;
  font-size: 0.92rem;
  line-height: 1.7;
  color: var(--rock);
}

.page-about .about-card-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.62rem;
  width: 0.5rem;
  height: 2px;
  background: var(--grass);
}

.page-about .about-card-panel .link-arrow {
  display: inline-block;
  margin-top: 1.15rem;
  font-size: 0.92rem;
  font-weight: 600;
  color: var(--ink-green);
}

/* ---------- 02 覆盖 ---------- */
.page-about .about-reach {
  background: var(--grass);
  color: var(--warm);
  padding-block: clamp(2.5rem, 6vw, 5rem);
}

.page-about .about-reach .eyebrow {
  color: var(--cream);
}

.page-about .about-reach .section-title {
  color: var(--warm);
}

.page-about .about-reach .lede {
  color: var(--warm-80);
}

.page-about .about-reach-grid {
  display: grid;
  gap: clamp(1.75rem, 4vw, 2.75rem);
}

.page-about .about-sub-title {
  margin: 0;
  font-family: var(--font-head);
  font-size: 1.2rem;
  font-weight: 700;
  letter-spacing: 0.03em;
  color: var(--cream);
}

.page-about .city-chips {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin: 1rem 0 0;
  padding: 0;
}

.page-about .city-chip {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  min-height: 44px;
  padding: 0.35rem 0.95rem;
  border-radius: 999px;
  border: 1px solid var(--about-rule-warm);
  background: rgba(251, 247, 238, 0.1);
  font-size: 0.92rem;
  color: var(--warm);
}

.page-about .city-chip--hub::before {
  content: "";
  width: 0.45rem;
  height: 0.45rem;
  border-radius: 50%;
  background: var(--orange);
}

.page-about .about-city-note {
  margin: 1.1rem 0 0;
  font-size: 0.92rem;
  line-height: 1.8;
  color: var(--warm-80);
  max-width: 34rem;
}

.page-about .cadence-list {
  list-style: none;
  margin: 1rem 0 0;
  padding: 0;
}

.page-about .cadence-list li {
  display: grid;
  grid-template-columns: 4.25rem minmax(0, 1fr);
  gap: 0.9rem;
  align-items: baseline;
  padding: 0.85rem 0;
  border-top: 1px solid var(--about-rule-warm);
}

.page-about .cadence-list li:last-child {
  border-bottom: 1px solid var(--about-rule-warm);
}

.page-about .cadence-key {
  font-family: var(--font-data);
  font-size: 0.78rem;
  letter-spacing: 0.1em;
  color: var(--cream);
}

.page-about .cadence-desc {
  font-size: 0.93rem;
  line-height: 1.78;
  color: var(--warm-80);
}

/* ---------- 03 时间线 ---------- */
.page-about .about-timeline {
  background: var(--night);
  color: var(--warm);
}

.page-about .about-timeline .eyebrow {
  color: var(--orange);
}

.page-about .about-timeline .section-title {
  color: var(--warm);
}

.page-about .about-timeline .lede {
  color: var(--warm-80);
}

.page-about .about-timeline-head {
  display: grid;
  gap: clamp(1.5rem, 3vw, 2.5rem);
  margin-bottom: clamp(1.75rem, 4vw, 2.75rem);
}

.page-about .about-timeline-media {
  margin: 0;
  border-radius: var(--r-lg);
  overflow: hidden;
  border: 1px solid var(--line-night-strong);
}

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

.page-about .timeline-track {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 1rem;
  position: relative;
}

.page-about .timeline-node {
  border-top: 1px solid var(--about-rule-night);
  padding-top: 0.85rem;
}

.page-about .timeline-details > summary {
  list-style: none;
  cursor: pointer;
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 0.35rem 0.7rem;
  padding: 0.2rem 0;
}

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

.page-about .timeline-details > summary:focus-visible {
  outline: 3px solid var(--orange);
  outline-offset: 3px;
}

.page-about .timeline-year {
  font-family: var(--font-data);
  font-size: clamp(1.5rem, 3.4vw, 2rem);
  font-weight: 700;
  line-height: 1;
  color: var(--orange);
}

.page-about .timeline-label {
  font-family: var(--font-head);
  font-size: 1.05rem;
  font-weight: 700;
  letter-spacing: 0.02em;
  color: var(--warm);
  transition: color 0.2s var(--ease);
}

.page-about .timeline-details > summary:hover .timeline-label {
  color: var(--cream);
}

.page-about .timeline-toggle {
  margin-left: auto;
  position: relative;
  width: 1rem;
  height: 1rem;
  flex: 0 0 auto;
  align-self: center;
}

.page-about .timeline-toggle::before,
.page-about .timeline-toggle::after {
  content: "";
  position: absolute;
  inset: 0;
  margin: auto;
  background: var(--warm-70);
}

.page-about .timeline-toggle::before {
  width: 100%;
  height: 1px;
}

.page-about .timeline-toggle::after {
  width: 1px;
  height: 100%;
  transition: transform 0.25s var(--ease);
}

.page-about .timeline-details[open] .timeline-toggle::after {
  transform: scaleY(0);
}

.page-about .timeline-body {
  padding: 0.55rem 0 0.35rem;
}

.page-about .timeline-body p {
  margin: 0;
  font-size: 0.94rem;
  line-height: 1.8;
  color: var(--warm-70);
}

/* ---------- 04 团队 ---------- */
.page-about .about-team {
  background: var(--cream);
  padding-block: clamp(2.5rem, 6vw, 5rem);
}

.page-about .about-team-grid {
  display: grid;
  gap: clamp(1.5rem, 3vw, 2.5rem);
}

.page-about .about-team-media {
  margin: 0;
  border-radius: var(--r-lg);
  overflow: hidden;
}

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

.page-about .role-radio {
  position: absolute;
  width: 1px;
  height: 1px;
  margin: -1px;
  padding: 0;
  overflow: hidden;
  clip-path: inset(50%);
  white-space: nowrap;
}

.page-about .role-tabrow {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.page-about .role-tab {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  min-height: 44px;
  padding: 0.4rem 1rem;
  border-radius: 999px;
  border: 1px solid var(--about-rule);
  background: var(--warm);
  font-size: 0.94rem;
  color: var(--ink-green);
  cursor: pointer;
  transition: background 0.2s var(--ease), color 0.2s var(--ease), border-color 0.2s var(--ease);
}

.page-about .role-tab .data-num {
  font-size: 0.82rem;
  color: var(--moss);
}

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

.page-about #about-role-a:checked ~ .role-tabrow .role-tab[for="about-role-a"],
.page-about #about-role-b:checked ~ .role-tabrow .role-tab[for="about-role-b"],
.page-about #about-role-c:checked ~ .role-tabrow .role-tab[for="about-role-c"],
.page-about #about-role-d:checked ~ .role-tabrow .role-tab[for="about-role-d"] {
  background: var(--grass);
  border-color: var(--grass);
  color: var(--warm);
}

.page-about #about-role-a:checked ~ .role-tabrow .role-tab[for="about-role-a"] .data-num,
.page-about #about-role-b:checked ~ .role-tabrow .role-tab[for="about-role-b"] .data-num,
.page-about #about-role-c:checked ~ .role-tabrow .role-tab[for="about-role-c"] .data-num,
.page-about #about-role-d:checked ~ .role-tabrow .role-tab[for="about-role-d"] .data-num {
  color: var(--cream);
}

.page-about #about-role-a:focus-visible ~ .role-tabrow .role-tab[for="about-role-a"],
.page-about #about-role-b:focus-visible ~ .role-tabrow .role-tab[for="about-role-b"],
.page-about #about-role-c:focus-visible ~ .role-tabrow .role-tab[for="about-role-c"],
.page-about #about-role-d:focus-visible ~ .role-tabrow .role-tab[for="about-role-d"] {
  outline: 3px solid var(--orange);
  outline-offset: 2px;
}

.page-about .role-panels {
  margin-top: 1rem;
}

.page-about .role-panel {
  display: none;
  background: var(--warm);
  border-radius: var(--r-md);
  border-left: 4px solid var(--grass);
  padding: clamp(1rem, 2.5vw, 1.4rem);
}

.page-about #about-role-a:checked ~ .role-panels .role-panel[data-role-panel="a"],
.page-about #about-role-b:checked ~ .role-panels .role-panel[data-role-panel="b"],
.page-about #about-role-c:checked ~ .role-panels .role-panel[data-role-panel="c"],
.page-about #about-role-d:checked ~ .role-panels .role-panel[data-role-panel="d"] {
  display: block;
}

.page-about .role-panel h3 {
  margin: 0;
  font-family: var(--font-head);
  font-size: 1.18rem;
  font-weight: 700;
  color: var(--ink-green);
}

.page-about .role-panel p {
  margin: 0.55rem 0 0;
  font-size: 0.95rem;
  line-height: 1.82;
  color: var(--rock);
}

.page-about .partner-row {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 0.75rem;
  margin-top: 1.5rem;
}

.page-about .partner-item {
  display: flex;
  align-items: baseline;
  gap: 0.65rem;
  padding: 0.85rem 1rem;
  background: rgba(251, 247, 238, 0.7);
  border: 1px solid var(--about-rule);
  border-radius: var(--r-sm);
}

.page-about .partner-num {
  font-family: var(--font-data);
  font-size: 1.5rem;
  font-weight: 700;
  line-height: 1;
  color: var(--ink-green);
  flex: 0 0 auto;
}

.page-about .partner-label {
  font-size: 0.9rem;
  line-height: 1.6;
  color: var(--rock);
}

/* ---------- 05 标准 ---------- */
.page-about .about-standard {
  background: var(--mist);
  padding-block: clamp(2.5rem, 6vw, 5rem);
}

.page-about .standard-grid {
  display: grid;
  gap: 0.9rem;
}

.page-about .standard-card {
  background: var(--warm);
  border-radius: var(--r-md);
  padding: clamp(1.1rem, 2.5vw, 1.5rem);
  border-top: 3px solid var(--grass);
}

.page-about .standard-card:nth-child(2) {
  border-top-color: var(--clay);
}

.page-about .standard-card:nth-child(3) {
  border-top-color: var(--moss);
}

.page-about .standard-index {
  margin: 0;
  font-family: var(--font-data);
  font-size: 0.78rem;
  letter-spacing: 0.16em;
  color: var(--moss);
}

.page-about .standard-card h3 {
  margin: 0.45rem 0 0;
  font-family: var(--font-head);
  font-size: 1.3rem;
  font-weight: 700;
  color: var(--ink-green);
}

.page-about .standard-card p {
  margin: 0.6rem 0 0;
  font-size: 0.94rem;
  line-height: 1.82;
  color: var(--rock);
}

.page-about .about-practice {
  margin-top: clamp(1.5rem, 3vw, 2.25rem);
}

.page-about .about-practice-title {
  margin: 0 0 0.5rem;
  font-family: var(--font-head);
  font-size: clamp(1.1rem, 2.2vw, 1.35rem);
  font-weight: 700;
  line-height: 1.3;
}

.page-about .about-practice p {
  margin: 0;
  font-size: 0.94rem;
  line-height: 1.82;
}

/* ---------- 下一步 ---------- */
.page-about .about-next {
  background: var(--warm);
  border-top: 1px solid var(--about-rule);
  padding-block: clamp(2.25rem, 5vw, 4rem);
}

.page-about .about-next-inner {
  display: grid;
  gap: clamp(1.25rem, 3vw, 2rem);
}

.page-about .about-next .section-title {
  margin: 0.45rem 0 0;
}

.page-about .about-next .lede {
  margin-top: 0.8rem;
  font-size: 1rem;
  line-height: 1.85;
  color: var(--rock);
}

.page-about .about-next-links {
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem;
  align-content: start;
}

/* ---------- 断点 ---------- */
@media (min-width: 600px) {
  .page-about .partner-row {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .page-about .partner-item {
    flex-direction: column;
    align-items: flex-start;
    gap: 0.4rem;
  }
}

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

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

  .page-about .about-reach-grid {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
    align-items: start;
  }
}

@media (min-width: 900px) {
  .page-about .about-hero-grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    align-items: end;
  }

  .page-about .about-origin-grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 4fr);
    align-items: start;
    gap: clamp(2rem, 4vw, 3.5rem);
  }

  .page-about .about-timeline-head {
    grid-template-columns: minmax(0, 6fr) minmax(0, 5fr);
    align-items: center;
    gap: clamp(2rem, 4vw, 3.5rem);
  }

  .page-about .about-team-grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 4fr);
    align-items: start;
    gap: clamp(2rem, 4vw, 3.5rem);
  }

  .page-about .about-team-media {
    position: sticky;
    top: 1.5rem;
  }

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

  .page-about .about-next-inner {
    grid-template-columns: minmax(0, 6fr) minmax(0, 5fr);
    align-items: end;
  }

  .page-about .about-next-links {
    justify-content: flex-end;
  }

  .page-about .timeline-track {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    column-gap: clamp(1rem, 2vw, 1.75rem);
    margin-top: 0.5rem;
  }

  .page-about .timeline-track::before {
    content: "";
    position: absolute;
    top: 0.55rem;
    left: 0;
    right: 0;
    height: 1px;
    background: var(--about-rule-night);
  }

  .page-about .timeline-node {
    position: relative;
    border-top: 0;
    padding-top: 2.25rem;
  }

  .page-about .timeline-node::before {
    content: "";
    position: absolute;
    top: 0;
    left: 0;
    width: 11px;
    height: 11px;
    border-radius: 50%;
    background: var(--night);
    border: 2px solid var(--moss);
  }

  .page-about .timeline-node:nth-child(3)::before {
    border-color: var(--clay);
  }

  .page-about .timeline-details > summary {
    display: block;
  }

  .page-about .timeline-label {
    display: block;
    margin-top: 0.3rem;
  }

  .page-about .timeline-toggle {
    position: absolute;
    right: 0;
    top: 0.4rem;
    margin: 0;
  }
}

@media (min-width: 1100px) {
  .page-about .about-hero-copy .lede {
    font-size: 1.15rem;
  }

  .page-about .about-head {
    max-width: 44rem;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .role-tab,
  .page-about .timeline-toggle::after,
  .page-about .timeline-label {
    transition: none;
  }
}