.page-about {
  --about-measure: 66ch;
  --about-line: var(--divider);
  color: var(--mist);
  padding-bottom: clamp(48px, 8vw, 104px);
}

.page-about a {
  color: inherit;
  text-decoration: none;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  width: min(100% - var(--gutter) * 2, var(--shell));
  margin-inline: auto;
  padding-block: clamp(16px, 3vw, 30px) clamp(30px, 5vw, 58px);
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  top: -14%;
  left: -12%;
  right: -28%;
  height: 128%;
  background-image:
    linear-gradient(to right, var(--grid) 1px, transparent 1px),
    linear-gradient(to bottom, var(--grid) 1px, transparent 1px);
  background-size: 96px 96px;
  opacity: 0.34;
  transform: skewY(-6deg);
  pointer-events: none;
  z-index: 0;
}

.page-about .about-crumbs {
  position: relative;
  z-index: 1;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.5em;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--sage);
  margin-bottom: clamp(18px, 3vw, 32px);
}

.page-about .about-crumbs a {
  color: var(--cyan-soft);
  border-bottom: 1px solid transparent;
  padding-bottom: 1px;
  transition: border-color 0.2s var(--ease);
}

.page-about .about-crumbs a:hover,
.page-about .about-crumbs a:focus-visible {
  border-bottom-color: var(--cyan);
}

.page-about .about-hero__grid {
  position: relative;
  z-index: 1;
  display: grid;
  gap: clamp(24px, 4vw, 40px);
  min-width: 0;
}

.page-about .about-hero__lead .eyebrow {
  color: var(--cyan);
  margin-bottom: 14px;
}

.page-about .about-hero h1 {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(30px, 6.4vw, 58px);
  line-height: 1.06;
  letter-spacing: -0.015em;
  margin: 0 0 clamp(14px, 2vw, 22px);
  max-width: 18ch;
  color: var(--mist);
  overflow-wrap: break-word;
}

.page-about .about-hero__intro {
  max-width: var(--about-measure);
  font-size: clamp(15px, 1.6vw, 17px);
  line-height: 1.8;
  color: var(--mist);
  margin: 0 0 clamp(18px, 3vw, 28px);
}

.page-about .about-hero__meta {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 0;
  margin: 0;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.04em;
  color: var(--sage);
}

.page-about .about-hero__meta span {
  display: inline-flex;
  align-items: center;
}

.page-about .about-hero__meta span + span::before {
  content: "";
  display: inline-block;
  width: 4px;
  height: 4px;
  margin: 0 12px;
  background: var(--amber);
  transform: rotate(45deg);
}

.page-about .about-quote {
  align-self: end;
  border-left: 2px solid var(--cyan);
  background: var(--surface);
  padding: clamp(18px, 3vw, 26px);
  border-top: 1px solid var(--about-line);
  border-right: 1px solid var(--about-line);
  border-bottom: 1px solid var(--about-line);
}

.page-about .about-quote__text {
  font-family: var(--font-serif);
  font-weight: 500;
  font-size: clamp(17px, 2.2vw, 21px);
  line-height: 1.6;
  color: var(--mist);
  margin: 0 0 12px;
}

.page-about .about-quote__from {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  color: var(--cyan-soft);
}

/* ---------- 主体布局 ---------- */
.page-about .about-body {
  width: min(100% - var(--gutter) * 2, var(--shell));
  margin-inline: auto;
  padding-top: clamp(26px, 4vw, 48px);
  display: grid;
  gap: clamp(26px, 4vw, 40px);
  min-width: 0;
}

.page-about .about-index {
  border: 1px solid var(--about-line);
  background: var(--surface);
  padding: 0;
  min-width: 0;
}

.page-about .about-index__summary {
  list-style: none;
  cursor: pointer;
  padding: 14px 16px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--cyan);
  border-bottom: 1px solid var(--about-line);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

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

.page-about .about-index__summary::after {
  content: "+";
  font-size: 14px;
  color: var(--sage);
}

.page-about .about-index[open] .about-index__summary::after {
  content: "−";
}

.page-about .about-index__list {
  list-style: none;
  margin: 0;
  padding: 8px 0;
  display: grid;
}

.page-about .about-index__list a {
  display: flex;
  align-items: baseline;
  gap: 10px;
  padding: 9px 16px;
  font-size: 14px;
  line-height: 1.5;
  color: var(--sage);
  border-left: 2px solid transparent;
  transition: color 0.2s var(--ease), border-color 0.2s var(--ease), background 0.2s var(--ease);
}

.page-about .about-index__list a span {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.06em;
  color: var(--amber);
}

.page-about .about-index__list a:hover,
.page-about .about-index__list a:focus-visible {
  color: var(--mist);
  border-left-color: var(--cyan);
  background: var(--surface-2);
}

/* ---------- 章节 ---------- */
.page-about .about-flow {
  display: grid;
  gap: clamp(44px, 7vw, 86px);
  min-width: 0;
}

.page-about .flow-section {
  display: grid;
  gap: clamp(16px, 2.4vw, 26px);
  min-width: 0;
}

.page-about .flow-head {
  display: grid;
  gap: 8px;
  padding-top: 16px;
  border-top: 1px solid var(--about-line);
}

.page-about .flow-num {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.2em;
  color: var(--amber);
}

.page-about .flow-head h2 {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(23px, 3.8vw, 36px);
  line-height: 1.14;
  letter-spacing: -0.01em;
  color: var(--mist);
  overflow-wrap: break-word;
}

.page-about .about-prose {
  margin: 0;
  max-width: var(--about-measure);
  font-size: 16px;
  line-height: 1.8;
  color: var(--mist);
}

.page-about .about-prose p {
  margin: 0 0 1em;
}

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

.page-about .about-split {
  display: grid;
  gap: clamp(18px, 3vw, 32px);
  min-width: 0;
}

.page-about .about-prose {
  display: grid;
  gap: 0;
  align-content: start;
  min-width: 0;
}

.page-about .about-prose p {
  max-width: var(--about-measure);
}

/* ---------- 图片 ---------- */
.page-about .about-figure {
  margin: 0;
  border: 1px solid var(--about-line);
  background: var(--surface);
  min-width: 0;
}

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

.page-about .about-figure figcaption {
  padding: 10px 14px;
  border-top: 1px solid var(--about-line);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.06em;
  line-height: 1.6;
  color: var(--sage);
}

.page-about .about-figure--inset img {
  aspect-ratio: 4 / 3;
}

/* ---------- 旁注卡 ---------- */
.page-about .about-note {
  background: var(--surface);
  border: 1px solid var(--about-line);
  border-left: 2px solid var(--violet);
  padding: clamp(16px, 2.6vw, 24px);
  min-width: 0;
}

.page-about .about-note--tall {
  align-self: start;
  border-left-color: var(--amber);
}

.page-about .about-note__title {
  margin: 0 0 12px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--cyan-soft);
}

.page-about .about-note__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 10px;
}

.page-about .about-note__list li {
  position: relative;
  padding-left: 16px;
  font-size: 14px;
  line-height: 1.72;
  color: var(--sage);
}

.page-about .about-note__list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.62em;
  width: 6px;
  height: 1px;
  background: var(--cyan);
}

/* ---------- 流程步骤 ---------- */
.page-about .flow-steps {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 0;
  border-top: 1px solid var(--about-line);
}

.page-about .flow-step {
  display: grid;
  grid-template-columns: 44px minmax(0, 1fr);
  gap: clamp(12px, 2vw, 20px);
  padding: clamp(16px, 2.4vw, 22px) 0;
  border-bottom: 1px solid var(--about-line);
}

.page-about .flow-step__num {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 20px;
  line-height: 1.2;
  letter-spacing: 0.04em;
  color: var(--amber);
}

.page-about .flow-step__body h3 {
  margin: 0 0 6px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 18px;
  letter-spacing: 0.02em;
  color: var(--cyan-soft);
}

.page-about .flow-step__body p {
  margin: 0;
  font-size: 15px;
  line-height: 1.78;
  color: var(--mist);
}

/* ---------- 折叠旁注 ---------- */
.page-about .note-details {
  border: 1px solid var(--about-line);
  background: var(--surface);
}

.page-about .note-details summary {
  cursor: pointer;
  list-style: none;
  padding: 14px 16px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--cyan);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}

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

.page-about .note-details summary::after {
  content: "+";
  font-size: 15px;
  color: var(--sage);
  flex: none;
}

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

.page-about .note-details__body {
  padding: 0 16px 18px;
  display: grid;
  gap: 14px;
}

.page-about .note-details__body ul {
  margin: 0;
  padding-left: 18px;
  display: grid;
  gap: 8px;
}

.page-about .note-details__body li {
  font-size: 14px;
  line-height: 1.74;
  color: var(--sage);
}

/* ---------- 团队 ---------- */
.page-about .team-grid {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--about-line);
  border: 1px solid var(--about-line);
}

.page-about .team-cell {
  background: var(--surface);
  padding: clamp(16px, 2.6vw, 22px);
  display: grid;
  gap: 4px;
  align-content: start;
  min-width: 0;
}

.page-about .team-cell__num {
  margin: 0;
  font-family: var(--font-mono);
  font-size: clamp(38px, 9vw, 62px);
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--cyan);
}

.page-about .team-cell__role {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 15px;
  letter-spacing: 0.06em;
  color: var(--mist);
}

.page-about .team-cell__desc {
  margin: 6px 0 0;
  font-size: 13.5px;
  line-height: 1.7;
  color: var(--sage);
}

/* ---------- 时间轴 ---------- */
.page-about .about-band {
  border: 1px solid var(--about-line);
  overflow: hidden;
  min-width: 0;
}

.page-about .about-band img {
  aspect-ratio: 2 / 1;
  clip-path: polygon(0 0, 100% 0, 100% 88%, 0 100%);
}

.page-about .journey-list {
  list-style: none;
  margin: 0;
  padding: 0 0 0 26px;
  position: relative;
  display: grid;
  gap: clamp(20px, 3vw, 30px);
}

.page-about .journey-list::before {
  content: "";
  position: absolute;
  left: 5px;
  top: 6px;
  bottom: 6px;
  width: 1px;
  background: linear-gradient(to bottom, var(--cyan), var(--violet));
}

.page-about .journey-item {
  position: relative;
  min-width: 0;
}

.page-about .journey-item::before {
  content: "";
  position: absolute;
  left: -25px;
  top: 9px;
  width: 9px;
  height: 9px;
  background: var(--ink);
  border: 1px solid var(--cyan);
  transform: rotate(45deg);
}

.page-about .journey-year {
  margin: 0 0 4px;
  font-family: var(--font-mono);
  font-size: 20px;
  letter-spacing: 0.08em;
  color: var(--amber);
}

.page-about .journey-item h3 {
  margin: 0 0 6px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 18px;
  letter-spacing: 0.02em;
  color: var(--mist);
}

.page-about .journey-item p:last-child {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.78;
  color: var(--sage);
}

/* ---------- 场景列表 ---------- */
.page-about .scene-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 10px;
}

.page-about .scene-list li {
  position: relative;
  padding-left: 16px;
  font-size: 14.5px;
  line-height: 1.75;
  color: var(--sage);
}

.page-about .scene-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.7em;
  width: 7px;
  height: 1px;
  background: var(--amber);
}

.page-about .scene-list strong {
  color: var(--mist);
  font-weight: 500;
}

/* ---------- 生态网格 ---------- */
.page-about .ecosystem-grid {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--about-line);
  border: 1px solid var(--about-line);
}

.page-about .ecosystem-cell {
  background: var(--ink-deep);
  padding: clamp(14px, 2.4vw, 20px);
  display: grid;
  gap: 4px;
  align-content: start;
  min-width: 0;
}

.page-about .ecosystem-cell__num {
  margin: 0;
  font-family: var(--font-mono);
  font-size: clamp(26px, 5vw, 34px);
  line-height: 1.1;
  color: var(--amber);
}

.page-about .ecosystem-cell__label {
  margin: 0;
  font-size: 14px;
  font-weight: 500;
  color: var(--mist);
}

.page-about .ecosystem-cell__desc {
  margin: 6px 0 0;
  font-size: 13px;
  line-height: 1.68;
  color: var(--sage);
}

/* ---------- 延伸入口 ---------- */
.page-about .next-grid {
  display: grid;
  gap: 1px;
  background: var(--about-line);
  border: 1px solid var(--about-line);
}

.page-about .next-card {
  position: relative;
  background: var(--surface);
  padding: clamp(16px, 2.6vw, 22px) clamp(16px, 2.6vw, 22px) clamp(16px, 2.6vw, 22px) 18px;
  display: grid;
  gap: 6px;
  align-content: start;
  min-width: 0;
  border-left: 2px solid transparent;
  transition: background 0.2s var(--ease), border-color 0.2s var(--ease);
}

.page-about .next-card::after {
  content: "→";
  position: absolute;
  right: 16px;
  top: 16px;
  font-family: var(--font-mono);
  font-size: 14px;
  color: var(--sage);
  transition: color 0.2s var(--ease), transform 0.2s var(--ease);
}

.page-about .next-card__label {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 17px;
  letter-spacing: 0.04em;
  color: var(--cyan-soft);
  padding-right: 26px;
}

.page-about .next-card__desc {
  font-size: 13.5px;
  line-height: 1.7;
  color: var(--sage);
}

.page-about .next-card:hover,
.page-about .next-card:focus-visible {
  background: var(--surface-2);
  border-left-color: var(--cyan);
}

.page-about .next-card:hover::after,
.page-about .next-card:focus-visible::after {
  color: var(--cyan);
  transform: translateX(3px);
}

/* ---------- 断点 ---------- */
@media (min-width: 640px) {
  .page-about .team-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

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

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

@media (min-width: 900px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 1.55fr) minmax(0, 0.85fr);
    align-items: end;
  }

  .page-about .about-split {
    grid-template-columns: minmax(0, 1.25fr) minmax(0, 0.9fr);
    align-items: start;
  }

  .page-about .about-split--reverse {
    grid-template-columns: minmax(0, 1.35fr) minmax(0, 0.75fr);
  }

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

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

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

  .page-about .about-hero h1 {
    max-width: 16ch;
  }
}

@media (min-width: 980px) {
  .page-about .about-body {
    grid-template-columns: 216px minmax(0, 1fr);
    gap: clamp(32px, 4vw, 64px);
    align-items: start;
  }

  .page-about .about-index {
    position: sticky;
    top: 104px;
  }

  .page-about .about-index__summary {
    cursor: default;
    pointer-events: none;
  }

  .page-about .about-index__summary::after {
    content: "";
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .next-card,
  .page-about .next-card::after,
  .page-about .about-index__list a,
  .page-about .about-crumbs a {
    transition: none;
  }
}