.page-about {
  --about-gap: clamp(1.25rem, 4vw, 3rem);
  --about-wash: rgba(102, 115, 111, 0.42);
  --about-text: rgba(244, 241, 232, 0.78);
  background: var(--ink);
  color: var(--paper);
  overflow-x: hidden;
}

.page-about a {
  transition: color 0.2s var(--ease), border-color 0.2s var(--ease), background-color 0.2s var(--ease);
}

.page-about a:focus-visible,
.page-about summary:focus-visible {
  outline: 2px solid var(--steel);
  outline-offset: 3px;
}

.page-about .eyebrow {
  font-family: var(--font-mono);
  font-size: 0.74rem;
  letter-spacing: 0.12em;
  color: var(--steel);
  margin: 0;
}

/* 面包屑 */
.page-about .about-crumb-bar {
  padding-block: clamp(1rem, 2.5vw, 1.5rem) 0;
}

.page-about .crumbs ol {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
  margin: 0;
  padding: 0;
  list-style: none;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.08em;
}

.page-about .crumbs li + li::before {
  content: "/";
  margin-right: 0.4rem;
  color: var(--line);
}

.page-about .crumbs a {
  color: var(--steel);
  text-decoration: none;
}

.page-about .crumbs a:hover {
  color: var(--flare);
}

.page-about .crumbs [aria-current="page"] {
  color: var(--paper);
}

/* 首屏 */
.page-about .about-hero {
  position: relative;
  padding-block: clamp(2rem, 5vw, 3.5rem) clamp(2.5rem, 6vw, 4.5rem);
  isolation: isolate;
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  z-index: -1;
  top: -12%;
  left: -30%;
  right: -30%;
  height: 150%;
  background:
    radial-gradient(circle at 22% 30%, rgba(28, 107, 74, 0.42), transparent 55%),
    radial-gradient(circle at 82% 68%, rgba(255, 90, 42, 0.2), transparent 58%);
  pointer-events: none;
}

.page-about .about-hero h1 {
  font-family: var(--font-head);
  font-weight: 900;
  font-size: clamp(2rem, 6vw, 3.9rem);
  line-height: 1.08;
  letter-spacing: -0.02em;
  margin: 0.75rem 0 1.25rem;
  max-width: 16ch;
}

.page-about .about-hero .lead {
  margin: 0;
  max-width: 60ch;
  font-size: clamp(0.98rem, 2.1vw, 1.1rem);
  line-height: 1.9;
  color: var(--about-text);
}

.page-about .about-anchors {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-top: clamp(1.75rem, 4vw, 2.75rem);
  padding-top: 1.1rem;
  border-top: var(--hairline);
}

.page-about .about-anchors a {
  font-family: var(--font-mono);
  font-size: 0.74rem;
  letter-spacing: 0.08em;
  color: var(--steel);
  text-decoration: none;
  padding: 0.45rem 0.85rem;
  border: 1px solid rgba(102, 115, 111, 0.5);
  border-radius: var(--r-pill);
}

.page-about .about-anchors a:hover,
.page-about .about-anchors a[aria-current="true"] {
  color: var(--flare);
  border-color: var(--flare);
  background: rgba(255, 90, 42, 0.09);
}

/* 通用章节 */
.page-about .about-section {
  padding-block: clamp(2.25rem, 6vw, 4.5rem);
  border-top: var(--hairline);
}

.page-about .chapter-head {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 0.75rem 1rem;
  align-items: start;
  padding-bottom: 1.1rem;
  margin-bottom: clamp(1.5rem, 4vw, 2.75rem);
  border-bottom: var(--hairline);
}

.page-about .chapter-index {
  font-family: var(--font-mono);
  font-size: 0.82rem;
  letter-spacing: 0.1em;
  color: var(--flare);
  margin: 0;
  padding-top: 0.35rem;
}

.page-about .chapter-title {
  font-family: var(--font-head);
  font-weight: 800;
  font-size: clamp(1.3rem, 3.4vw, 2rem);
  line-height: 1.25;
  letter-spacing: -0.02em;
  margin: 0;
  color: var(--paper);
}

.page-about .about-dek {
  margin: 0.55rem 0 0;
  max-width: 56ch;
  font-size: 0.92rem;
  line-height: 1.8;
  color: var(--steel);
}

/* 图片容器 */
.page-about .img-frame {
  position: relative;
  margin: 0;
  border-radius: var(--r-lg);
  overflow: hidden;
  background: var(--carbon);
  border: var(--hairline);
}

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

.page-about .img-frame figcaption {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.08em;
  line-height: 1.6;
  color: var(--steel);
  padding: 0.65rem 0.9rem 0;
}

/* 01 时间线 */
.page-about .about-timeline-body {
  display: grid;
  gap: clamp(1.75rem, 4vw, 3rem);
}

.page-about .timeline-list {
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .timeline-item {
  position: relative;
  display: grid;
  grid-template-columns: 3.2rem minmax(0, 1fr);
  column-gap: clamp(0.75rem, 2vw, 1.5rem);
  padding-bottom: clamp(1.6rem, 3.2vw, 2.4rem);
}

.page-about .timeline-rail {
  position: relative;
  padding-right: 0.85rem;
  text-align: right;
}

.page-about .timeline-rail::after {
  content: "";
  position: absolute;
  top: 1.9rem;
  right: 0;
  bottom: calc(-1 * clamp(1.6rem, 3.2vw, 2.4rem));
  width: 1px;
  background: var(--about-wash);
}

.page-about .timeline-item:last-child .timeline-rail::after {
  display: none;
}

.page-about .timeline-dot {
  position: absolute;
  top: 0.75rem;
  right: -4px;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--flare);
  box-shadow: 0 0 0 4px rgba(255, 90, 42, 0.16);
}

.page-about .timeline-year {
  font-family: var(--font-mono);
  font-size: 0.74rem;
  letter-spacing: 0.05em;
  color: var(--steel);
  line-height: 1.5;
  display: block;
}

.page-about .timeline-card {
  padding-top: 0.55rem;
  border-top: 1px solid rgba(102, 115, 111, 0.28);
}

.page-about .timeline-stage {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.12em;
  color: var(--turf);
}

.page-about .timeline-card h3 {
  font-family: var(--font-head);
  font-weight: 800;
  font-size: clamp(1.02rem, 2.4vw, 1.24rem);
  line-height: 1.4;
  letter-spacing: -0.01em;
  margin: 0.35rem 0 0.55rem;
  color: var(--paper);
}

.page-about .timeline-card p:last-child {
  margin: 0;
  font-size: 0.92rem;
  line-height: 1.85;
  color: var(--about-text);
}

.page-about .timeline-figure {
  align-self: start;
}

/* 02 团队分工 */
.page-about .team-grid {
  display: grid;
  gap: 1px;
  background: rgba(102, 115, 111, 0.35);
  border: var(--hairline);
  border-radius: var(--r-md);
  overflow: hidden;
}

.page-about .team-item {
  background: var(--carbon);
  padding: clamp(1.2rem, 3vw, 1.8rem);
}

.page-about .team-role-index {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.12em;
  color: var(--flare);
  margin-bottom: 0.7rem;
}

.page-about .team-item h3 {
  font-family: var(--font-head);
  font-weight: 800;
  font-size: 1.1rem;
  letter-spacing: -0.01em;
  margin: 0 0 0.6rem;
  color: var(--paper);
}

.page-about .team-item p {
  margin: 0;
  font-size: 0.9rem;
  line-height: 1.85;
  color: var(--about-text);
}

.page-about .about-team-figure {
  margin-top: clamp(1.5rem, 3.5vw, 2.25rem);
}

/* 03 校对流程（暖白反色区） */
.page-about .about-process {
  background: var(--paper);
  color: var(--carbon);
  border-top: none;
}

.page-about .about-process .chapter-head {
  border-bottom-color: rgba(102, 115, 111, 0.5);
}

.page-about .about-process .chapter-title {
  color: var(--carbon);
}

.page-about .about-process .chapter-index {
  color: var(--flare);
}

.page-about .about-process .about-dek {
  color: rgba(14, 20, 18, 0.7);
}

.page-about .flow-line {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.5rem 0.7rem;
  list-style: none;
  margin: 0 0 clamp(1.25rem, 3vw, 1.75rem);
  padding: 0;
}

.page-about .flow-node {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  letter-spacing: 0.12em;
  padding: 0.35rem 0.95rem;
  border: 1px solid rgba(14, 20, 18, 0.28);
  border-radius: var(--r-pill);
  color: var(--carbon);
}

.page-about .flow-node:last-child {
  background: var(--carbon);
  color: var(--paper);
  border-color: var(--carbon);
}

.page-about .flow-arrow {
  display: flex;
  color: var(--flare);
}

.page-about .stepfold {
  border-top: 1px solid rgba(102, 115, 111, 0.45);
  padding: 0.2rem 0;
}

.page-about .stepfold:last-of-type {
  border-bottom: 1px solid rgba(102, 115, 111, 0.45);
}

.page-about .stepfold summary {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 0.65rem;
  cursor: pointer;
  list-style: none;
  padding: 0.95rem 0;
  font-family: var(--font-head);
  font-weight: 800;
  font-size: clamp(0.98rem, 2.3vw, 1.16rem);
  line-height: 1.5;
  color: var(--carbon);
}

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

.page-about .stepfold summary::after {
  content: "+";
  margin-left: auto;
  font-family: var(--font-mono);
  font-weight: 400;
  font-size: 1.25rem;
  line-height: 1;
  color: var(--flare);
}

.page-about .stepfold[open] summary::after {
  content: "−";
}

.page-about .step-num {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.12em;
  color: var(--flare);
  white-space: nowrap;
}

.page-about .stepfold p {
  margin: 0 0 1.1rem;
  max-width: 64ch;
  font-size: 0.92rem;
  line-height: 1.9;
  color: rgba(14, 20, 18, 0.78);
}

/* 04 合作生态 */
.page-about .partner-body {
  display: grid;
  gap: clamp(1.5rem, 4vw, 2.5rem);
}

.page-about .partner-copy p {
  margin: 0 0 1rem;
  font-size: 0.92rem;
  line-height: 1.9;
  color: var(--about-text);
}

.page-about .stat-strip {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
  gap: 1px;
  margin-top: 1.5rem;
  background: rgba(102, 115, 111, 0.35);
  border: var(--hairline);
  border-radius: var(--r-md);
  overflow: hidden;
}

.page-about .stat-cell {
  background: var(--carbon);
  padding: 1rem 1.05rem;
}

.page-about .stat-num {
  display: block;
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: clamp(1.5rem, 4vw, 2.1rem);
  line-height: 1;
  color: var(--flare);
  font-variant-numeric: tabular-nums;
}

.page-about .stat-label {
  display: block;
  margin-top: 0.4rem;
  font-size: 0.76rem;
  letter-spacing: 0.02em;
  color: var(--steel);
}

.page-about .partner-figure {
  align-self: start;
}

/* 05 联络 */
.page-about .reach-grid {
  display: grid;
  gap: 1.1rem;
}

.page-about .reach-card {
  background: var(--carbon);
  border: var(--hairline);
  border-radius: var(--r-lg);
  padding: clamp(1.2rem, 3vw, 1.9rem);
}

.page-about .reach-card h3 {
  font-family: var(--font-head);
  font-weight: 800;
  font-size: 1.08rem;
  letter-spacing: -0.01em;
  margin: 0 0 0.9rem;
  color: var(--paper);
}

.page-about .reach-card p {
  margin: 0 0 0.85rem;
  font-size: 0.9rem;
  line-height: 1.85;
  color: var(--about-text);
}

.page-about .reach-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 0.85rem;
}

.page-about .reach-list li {
  display: grid;
  gap: 0.2rem;
  padding-bottom: 0.85rem;
  border-bottom: 1px solid rgba(102, 115, 111, 0.28);
}

.page-about .reach-list li:last-child {
  padding-bottom: 0;
  border-bottom: none;
}

.page-about .reach-key {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.12em;
  color: var(--steel);
}

.page-about .reach-val {
  font-size: 0.94rem;
  line-height: 1.7;
  color: var(--paper);
  overflow-wrap: anywhere;
}

.page-about .reach-val a {
  color: var(--paper);
  text-decoration: underline;
  text-decoration-color: rgba(255, 90, 42, 0.55);
  text-underline-offset: 3px;
}

.page-about .reach-val a:hover {
  color: var(--flare);
}

.page-about .about-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem;
  margin-top: 1.25rem;
}

.page-about .btn {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  letter-spacing: 0.06em;
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  padding: 0.62rem 1.15rem;
  border-radius: var(--r-pill);
}

.page-about .btn--flare {
  background: var(--flare);
  color: var(--carbon);
  border: 1px solid var(--flare);
  font-weight: 700;
}

.page-about .btn--flare:hover {
  background: var(--signal);
  border-color: var(--signal);
  color: var(--carbon);
}

.page-about .btn--ghost {
  color: var(--paper);
  border: 1px solid rgba(183, 195, 192, 0.55);
}

.page-about .btn--ghost:hover {
  color: var(--flare);
  border-color: var(--flare);
}

.page-about .btn--quiet {
  color: var(--steel);
  border: 1px solid transparent;
}

.page-about .btn--quiet:hover {
  color: var(--flare);
}

/* 响应式 */
@media (min-width: 640px) {
  .page-about .timeline-item {
    grid-template-columns: 4.4rem minmax(0, 1fr);
  }

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

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

@media (min-width: 900px) {
  .page-about .about-timeline-body {
    grid-template-columns: minmax(0, 1.3fr) minmax(0, 1fr);
    align-items: start;
  }

  .page-about .timeline-figure {
    position: sticky;
    top: 5.5rem;
  }

  .page-about .partner-body {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1.05fr);
    align-items: center;
  }

  .page-about .chapter-head {
    gap: 1.25rem 2rem;
  }

  .page-about .chapter-index {
    font-size: 0.9rem;
    padding-top: 0.5rem;
  }
}

@media (min-width: 1200px) {
  .page-about .about-hero h1 {
    max-width: 14ch;
  }
}