.page-about {
  --about-gap: clamp(20px, 4vw, 36px);
  --sec: var(--sand);
  background-color: var(--ink-800);
  color: var(--paper);
  font-family: var(--font-body);
  font-size: var(--fs-16);
  line-height: 1.75;
  overflow-x: hidden;
}

.page-about .about-inner {
  width: 100%;
  max-width: var(--wrap);
  margin-inline: auto;
  padding-inline: var(--pad-x);
}

/* ---------- 首屏 ---------- */
.page-about .about-head {
  position: relative;
  border-bottom: 1px solid var(--line-strong);
  background-color: var(--ink-900);
  background-image:
    repeating-linear-gradient(90deg, rgba(216, 162, 74, 0.07) 0 1px, transparent 1px 96px),
    repeating-linear-gradient(0deg, rgba(216, 162, 74, 0.05) 0 1px, transparent 1px 96px);
  padding-block: clamp(20px, 4vw, 36px) clamp(32px, 6vw, 64px);
}

.page-about .about-kicker {
  display: flex;
  align-items: center;
  gap: 10px;
  margin: clamp(20px, 4vw, 32px) 0 18px;
  font-family: var(--font-mono);
  font-size: var(--fs-12);
  letter-spacing: 0.18em;
  color: var(--sand);
}

.page-about .about-kicker::before {
  content: "";
  width: 30px;
  height: 1px;
  background: var(--sand);
  flex: none;
}

.page-about .about-title {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(2rem, 6.4vw, 4.2rem);
  line-height: 1.12;
  letter-spacing: 0.01em;
  margin: 0 0 20px;
  max-width: 20ch;
  color: var(--paper);
}

.page-about .about-title em {
  font-style: normal;
  color: var(--sand);
  display: inline-block;
  border-bottom: 3px solid rgba(216, 162, 74, 0.35);
  padding-bottom: 2px;
}

.page-about .about-lede {
  max-width: 62ch;
  margin: 0 0 clamp(24px, 4vw, 34px);
  font-size: var(--fs-16);
  color: var(--stone);
  line-height: 1.8;
}

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

.page-about .about-jump__link {
  display: inline-block;
  padding: 7px 14px;
  font-size: var(--fs-14);
  font-weight: 500;
  color: var(--paper);
  text-decoration: none;
  border: 1px solid var(--line-soft);
  border-radius: 999px;
  background: rgba(46, 66, 71, 0.5);
  transition: background 0.22s var(--ease), border-color 0.22s var(--ease), color 0.22s var(--ease);
}

.page-about .about-jump__link:hover,
.page-about .about-jump__link:focus-visible {
  background: var(--sand);
  border-color: var(--sand);
  color: var(--ink-900);
}

/* ---------- 章节基础 ---------- */
.page-about .about-sec {
  padding-block: clamp(40px, 6.5vw, 76px);
}

.page-about .about-sec + .about-sec {
  border-top: 1px solid var(--line-faint);
}

.page-about .about-sec--lake {
  --sec: var(--lake);
  background: linear-gradient(180deg, rgba(62, 142, 158, 0.08), transparent 62%);
}

.page-about .about-sec--indigo {
  --sec: var(--indigo);
  background: linear-gradient(180deg, rgba(75, 63, 114, 0.16), transparent 70%);
}

.page-about .sec-head {
  display: grid;
  gap: 10px;
  margin-bottom: clamp(24px, 4vw, 40px);
  max-width: 74ch;
}

.page-about .sec-index {
  font-family: var(--font-mono);
  font-size: var(--fs-12);
  letter-spacing: 0.2em;
  color: var(--sec);
}

.page-about .sec-head h2 {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(1.5rem, 3.8vw, 2.4rem);
  line-height: 1.18;
  margin: 0;
  color: var(--paper);
}

.page-about .sec-lede {
  margin: 0;
  max-width: 64ch;
  font-size: var(--fs-16);
  color: var(--stone);
  line-height: 1.8;
}

/* ---------- 时间轴 ---------- */
.page-about .trail {
  list-style: none;
  margin: 0;
  padding: 0 0 0 clamp(18px, 4vw, 40px);
  border-left: 1px dashed var(--line-strong);
  display: grid;
  gap: clamp(22px, 3.4vw, 34px);
}

.page-about .trail__item {
  position: relative;
}

.page-about .trail__item::before {
  content: "";
  position: absolute;
  top: 0.95em;
  left: calc(-1 * clamp(18px, 4vw, 40px) - 5px);
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--sand);
  box-shadow: 0 0 0 4px var(--ink-800);
}

.page-about .trail__year {
  display: inline-block;
  margin-bottom: 8px;
  padding: 2px 9px;
  font-family: var(--font-mono);
  font-size: var(--fs-12);
  letter-spacing: 0.12em;
  color: var(--sand);
  border: 1px solid var(--line-strong);
  border-radius: var(--radius-s);
}

.page-about .trail__title {
  margin: 0 0 6px;
  font-family: var(--font-display);
  font-size: var(--fs-18);
  font-weight: 800;
  line-height: 1.35;
  color: var(--paper);
}

.page-about .trail__text {
  margin: 0;
  max-width: 62ch;
  font-size: var(--fs-16);
  color: var(--stone);
  line-height: 1.75;
}

/* ---------- 数据条 ---------- */
.page-about .stat-row {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px 10px;
  list-style: none;
  margin: 0 0 var(--about-gap);
  padding: 0;
}

.page-about .stat {
  border-left: 2px solid var(--sec);
  padding: 2px 0 2px 12px;
}

.page-about .stat__num {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(1.5rem, 4.4vw, 2.3rem);
  line-height: 1.1;
  color: var(--paper);
}

.page-about .stat__label {
  display: block;
  margin-top: 2px;
  font-size: var(--fs-14);
  color: var(--stone);
}

/* ---------- 区域 ---------- */
.page-about .zone-split {
  display: grid;
  gap: var(--about-gap);
}

.page-about .about-figure {
  margin: 0;
}

.page-about .about-figure img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  border-radius: var(--radius-m);
  border: 1px solid var(--line-soft);
  background: var(--glass);
  object-fit: cover;
}

.page-about .about-figure figcaption {
  margin-top: 10px;
  padding-left: 10px;
  border-left: 2px solid var(--sec);
  font-size: var(--fs-12);
  line-height: 1.65;
  color: var(--stone);
}

.page-about .about-figure--wide {
  margin-top: var(--about-gap);
}

.page-about .zone-grid {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 10px;
}

.page-about .zone {
  padding: 14px 16px 16px;
  border: 1px solid var(--line-soft);
  border-radius: var(--radius-m);
  background: rgba(46, 66, 71, 0.45);
  transition: transform 0.22s var(--ease), border-color 0.22s var(--ease), background 0.22s var(--ease);
}

.page-about .zone:hover,
.page-about .zone:focus-within {
  transform: translateY(-2px);
  border-color: var(--sand);
  background: rgba(46, 66, 71, 0.85);
}

.page-about .zone__no {
  font-family: var(--font-mono);
  font-size: var(--fs-12);
  letter-spacing: 0.14em;
  color: var(--sand);
}

.page-about .zone h3 {
  margin: 4px 0 6px;
  font-family: var(--font-display);
  font-size: var(--fs-18);
  font-weight: 800;
  line-height: 1.3;
  color: var(--paper);
}

.page-about .zone p {
  margin: 0;
  font-size: var(--fs-14);
  line-height: 1.7;
  color: var(--stone);
}

/* ---------- 团队 ---------- */
.page-about .crew-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 14px;
}

.page-about .crew {
  padding: 18px 18px 22px;
  border-top: 3px solid var(--sand);
  border-radius: var(--radius-m);
  background: var(--ink-700);
}

.page-about .crew:nth-child(2) {
  border-top-color: var(--lake);
}

.page-about .crew:nth-child(3) {
  border-top-color: var(--coral);
}

.page-about .crew__no {
  font-family: var(--font-mono);
  font-size: var(--fs-12);
  letter-spacing: 0.16em;
  color: var(--stone);
}

.page-about .crew h3 {
  margin: 6px 0 10px;
  font-family: var(--font-display);
  font-size: var(--fs-24);
  font-weight: 800;
  line-height: 1.25;
  color: var(--paper);
}

.page-about .crew p {
  margin: 0 0 12px;
  font-size: var(--fs-14);
  line-height: 1.75;
  color: var(--stone);
}

.page-about .crew ul {
  margin: 0;
  padding-left: 1.1em;
  font-size: var(--fs-14);
  line-height: 1.7;
  color: var(--stone);
}

.page-about .crew li + li {
  margin-top: 8px;
}

.page-about .crew li::marker {
  color: var(--sand);
}

/* ---------- 知识库 ---------- */
.page-about .kb-layout {
  display: grid;
  gap: var(--about-gap);
}

.page-about .kb-panel {
  display: grid;
  gap: 18px;
}

.page-about .kb-cats {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 8px;
}

.page-about .kb-cat {
  padding: 12px 14px;
  border-left: 2px solid var(--indigo);
  background: rgba(243, 237, 227, 0.04);
  border-radius: 0 var(--radius-m) var(--radius-m) 0;
}

.page-about .kb-cat h3 {
  margin: 0 0 4px;
  font-family: var(--font-display);
  font-size: var(--fs-16);
  font-weight: 800;
  color: var(--paper);
}

.page-about .kb-cat p {
  margin: 0;
  font-size: var(--fs-14);
  line-height: 1.65;
  color: var(--stone);
}

.page-about .kb-side {
  display: grid;
  gap: 16px;
}

.page-about .kb-stats {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 10px;
  padding: 16px 0;
  border-top: 1px solid var(--line-strong);
  border-bottom: 1px solid var(--line-strong);
}

.page-about .kb-stat {
  display: grid;
  gap: 4px;
}

.page-about .kb-stat__num {
  font-family: var(--font-mono);
  font-size: clamp(1.5rem, 5vw, 2.2rem);
  line-height: 1.05;
  color: var(--sand);
}

.page-about .kb-stat__label {
  font-size: var(--fs-12);
  line-height: 1.5;
  color: var(--stone);
}

.page-about .kb-note {
  margin: 0;
  font-size: var(--fs-14);
  line-height: 1.75;
  color: var(--stone);
}

.page-about .kb-fold {
  border: 1px solid var(--line-soft);
  border-radius: var(--radius-m);
  background: rgba(75, 63, 114, 0.22);
  padding: 12px 14px;
}

.page-about .kb-fold + .kb-fold {
  margin-top: 8px;
}

.page-about .kb-fold summary {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  cursor: pointer;
  list-style: none;
  font-size: var(--fs-16);
  font-weight: 500;
  color: var(--paper);
}

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

.page-about .kb-fold summary::after {
  content: "+";
  flex: none;
  font-family: var(--font-mono);
  font-size: var(--fs-18);
  color: var(--sand);
}

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

.page-about .kb-fold summary:focus-visible {
  outline: 2px solid var(--sand);
  outline-offset: 3px;
}

.page-about .kb-fold p {
  margin: 12px 0 0;
  font-size: var(--fs-14);
  line-height: 1.75;
  color: var(--stone);
}

/* ---------- 协作 ---------- */
.page-about .partner-grid {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 12px;
}

.page-about .partner {
  padding: 18px 18px 20px;
  border: 1px solid var(--line-soft);
  border-radius: var(--radius-m);
  background: rgba(30, 42, 46, 0.6);
}

.page-about .partner__tag {
  display: inline-block;
  margin-bottom: 10px;
  padding: 2px 9px;
  font-family: var(--font-mono);
  font-size: var(--fs-12);
  letter-spacing: 0.1em;
  color: var(--ink-900);
  background: var(--sand);
  border-radius: var(--radius-s);
}

.page-about .partner h3 {
  margin: 0 0 8px;
  font-family: var(--font-display);
  font-size: var(--fs-18);
  font-weight: 800;
  line-height: 1.32;
  color: var(--paper);
}

.page-about .partner p {
  margin: 0;
  font-size: var(--fs-14);
  line-height: 1.72;
  color: var(--stone);
}

.page-about .partner-more {
  margin: 18px 0 0;
  max-width: 62ch;
  font-size: var(--fs-16);
  line-height: 1.8;
  color: var(--stone);
}

.page-about .partner-more a {
  color: var(--lake);
  font-weight: 500;
  text-decoration: underline;
  text-underline-offset: 3px;
}

.page-about .partner-more a:hover,
.page-about .partner-more a:focus-visible {
  color: var(--sand);
}

/* ---------- 结尾 ---------- */
.page-about .about-next {
  background: var(--ink-900);
  border-top: 1px solid var(--line-strong);
}

.page-about .next-panel {
  border-left: 4px solid var(--coral);
  padding-left: clamp(16px, 3vw, 28px);
}

.page-about .next-panel h2 {
  margin: 0 0 12px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(1.4rem, 3.4vw, 2rem);
  line-height: 1.2;
  color: var(--paper);
}

.page-about .next-panel p {
  margin: 0 0 22px;
  max-width: 58ch;
  font-size: var(--fs-16);
  line-height: 1.8;
  color: var(--stone);
}

.page-about .next-links {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.page-about .about-cta {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 11px 18px;
  font-size: var(--fs-14);
  font-weight: 600;
  text-decoration: none;
  color: var(--paper);
  border: 1px solid var(--line-strong);
  border-radius: var(--radius-s);
  background: transparent;
  transition: background 0.22s var(--ease), border-color 0.22s var(--ease), color 0.22s var(--ease);
}

.page-about .about-cta:hover,
.page-about .about-cta:focus-visible {
  background: rgba(216, 162, 74, 0.14);
  border-color: var(--sand);
  color: var(--sand);
}

.page-about .about-cta--solid {
  background: var(--coral);
  border-color: var(--coral);
  color: var(--ink-900);
}

.page-about .about-cta--solid:hover,
.page-about .about-cta--solid:focus-visible {
  background: var(--sand);
  border-color: var(--sand);
  color: var(--ink-900);
}

/* ---------- 响应式 ---------- */
@media (min-width: 620px) {
  .page-about .zone-grid,
  .page-about .partner-grid,
  .page-about .kb-cats {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (min-width: 720px) {
  .page-about .stat-row {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

@media (min-width: 860px) {
  .page-about .crew-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    align-items: start;
  }

  .page-about .crew:nth-child(2) {
    margin-top: 28px;
  }

  .page-about .crew:nth-child(3) {
    margin-top: 56px;
  }
}

@media (min-width: 900px) {
  .page-about .zone-split {
    grid-template-columns: minmax(0, 0.85fr) minmax(0, 1.15fr);
    align-items: start;
  }

  .page-about .kb-layout {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, 0.95fr);
    align-items: start;
  }

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

@media (prefers-reduced-motion: reduce) {
  .page-about .about-jump__link,
  .page-about .zone,
  .page-about .about-cta {
    transition: none;
  }

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