.page-about {
  --about-gap: clamp(20px, 3.4vw, 40px);
  --about-soft: rgba(248, 250, 252, 0.82);
}

/* ---------- 面包屑 ---------- */
.page-about .breadcrumb {
  margin-bottom: clamp(18px, 3vw, 30px);
}

.page-about .breadcrumb-list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 6px;
  margin: 0;
  padding: 0;
  list-style: none;
  font-size: 13px;
  letter-spacing: 0.04em;
  color: var(--muted);
}

.page-about .breadcrumb-item + .breadcrumb-item::before {
  content: "/";
  margin-right: 6px;
  color: var(--slate);
}

.page-about .breadcrumb-item a {
  color: var(--ice);
  text-decoration: none;
  transition: color 0.2s var(--ease);
}

.page-about .breadcrumb-item a:hover {
  color: var(--lime);
}

.page-about .breadcrumb-item.is-current {
  color: var(--paper);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  padding: clamp(24px, 5vw, 56px) 0 clamp(30px, 5vw, 60px);
}

.page-about .hero-split {
  display: grid;
  gap: var(--about-gap);
}

.page-about .hero-kicker {
  margin: 0 0 14px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.3em;
  text-transform: uppercase;
  color: var(--lime);
}

.page-about h1 {
  margin: 0 0 clamp(16px, 2.4vw, 24px);
  font-size: clamp(32px, 6.6vw, 68px);
  line-height: 1.05;
  font-weight: 900;
  letter-spacing: -0.02em;
  color: var(--paper);
}

.page-about .hl {
  display: inline-block;
  padding: 0 0.14em;
  background: var(--lime);
  color: var(--ink);
  transform: skewX(-4deg);
}

.page-about .hero-lede {
  max-width: 60ch;
  margin: 0 0 clamp(20px, 3vw, 28px);
  font-size: clamp(15px, 1.6vw, 16.5px);
  line-height: 1.78;
  color: var(--about-soft);
}

.page-about .hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.page-about .hero-aside {
  display: flex;
  gap: clamp(14px, 2vw, 22px);
  padding: clamp(16px, 2.4vw, 22px);
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  background: linear-gradient(155deg, rgba(30, 41, 59, 0.78), rgba(10, 15, 31, 0.72));
  box-shadow: var(--shadow-card);
}

.page-about .hero-vertical {
  writing-mode: vertical-rl;
  text-orientation: mixed;
  margin: 0;
  padding-right: 12px;
  border-right: 1px dashed var(--line);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.3em;
  color: var(--ice);
}

.page-about .hero-stats {
  flex: 1;
  display: grid;
  gap: clamp(12px, 1.8vw, 18px);
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .hero-stats li {
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding-top: 10px;
  border-top: 1px solid var(--line);
}

.page-about .hero-stats li:first-child {
  padding-top: 0;
  border-top: 0;
}

.page-about .hero-stats .score {
  font-family: var(--font-mono);
  font-size: clamp(24px, 3.4vw, 36px);
  font-weight: 700;
  line-height: 1;
  color: var(--lime);
  letter-spacing: -0.02em;
}

.page-about .hero-stats .score sup {
  font-size: 0.48em;
  color: var(--orange);
  vertical-align: super;
}

.page-about .hero-stat-label {
  font-size: 13px;
  color: var(--muted);
}

.page-about .hero-figure {
  margin: clamp(26px, 4vw, 44px) 0 0;
}

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

.page-about .img-caption {
  margin: 10px 0 0;
  font-size: 12.5px;
  line-height: 1.6;
  color: var(--muted);
}

/* ---------- 目录导轨 ---------- */
.page-about .about-toc {
  padding: 0 var(--gutter) clamp(26px, 4vw, 44px);
}

.page-about .toc-inner {
  display: flex;
  gap: 8px;
  overflow-x: auto;
  padding: 9px clamp(12px, 2vw, 18px);
  border: 1px solid var(--line);
  border-radius: var(--pill);
  background: rgba(17, 24, 39, 0.72);
  scrollbar-width: none;
}

.page-about .toc-inner::-webkit-scrollbar {
  display: none;
}

.page-about .spy-link {
  flex: 0 0 auto;
  padding: 8px 15px;
  border: 1px solid transparent;
  border-radius: var(--pill);
  font-size: 13px;
  color: var(--muted);
  text-decoration: none;
  white-space: nowrap;
  transition: color 0.2s var(--ease), background 0.2s var(--ease), border-color 0.2s var(--ease);
}

.page-about .spy-link:hover {
  color: var(--paper);
  border-color: var(--ice);
}

.page-about .spy-link.is-active {
  color: var(--ink);
  font-weight: 700;
  background: var(--lime);
  border-color: var(--lime);
}

/* ---------- 通用章节 ---------- */
.page-about .about-section {
  padding: clamp(36px, 6.5vw, 80px) 0;
}

.page-about .about-section + .about-section,
.page-about .about-toc + .about-section {
  border-top: 1px solid var(--line);
}

.page-about .about-grid {
  display: grid;
  gap: clamp(20px, 3.4vw, 42px);
}

.page-about .about-rail {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.page-about .rail-num {
  font-family: var(--font-mono);
  font-size: clamp(44px, 7vw, 74px);
  font-weight: 700;
  line-height: 0.9;
  letter-spacing: -0.05em;
  color: var(--slate);
}

.page-about .rail-title {
  margin: 0;
  font-size: clamp(21px, 2.6vw, 30px);
  line-height: 1.22;
  font-weight: 800;
  letter-spacing: -0.01em;
  color: var(--paper);
}

.page-about .rail-note {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.2em;
  color: var(--ice);
}

.page-about .about-body {
  display: flex;
  flex-direction: column;
  gap: clamp(16px, 2.4vw, 24px);
  font-size: 15.5px;
  line-height: 1.78;
  color: var(--about-soft);
}

.page-about .about-body p {
  margin: 0;
}

.page-about .lead-p {
  font-size: clamp(16px, 1.8vw, 19px);
  line-height: 1.68;
  color: var(--paper);
}

/* ---------- 四层结构 ---------- */
.page-about .layer-list {
  display: grid;
  gap: 12px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .layer-item {
  padding: 16px 18px;
  border: 1px solid var(--line);
  border-left: 3px solid var(--lime);
  border-radius: var(--radius);
  background: var(--ink-2);
}

.page-about .layer-item:nth-child(2) {
  border-left-color: var(--orange);
}

.page-about .layer-item:nth-child(3) {
  border-left-color: var(--ice);
}

.page-about .layer-item:nth-child(4) {
  border-left-color: var(--muted);
}

.page-about .layer-name {
  margin: 0;
  font-size: 16px;
  font-weight: 700;
  color: var(--paper);
}

.page-about .layer-item p {
  margin: 8px 0 0;
  font-size: 14px;
  line-height: 1.72;
  color: var(--muted);
}

/* ---------- 章节标题 ---------- */
.page-about .sec-head {
  max-width: 62ch;
  margin-bottom: clamp(22px, 3.6vw, 38px);
}

.page-about .sec-head h2 {
  margin: 0 0 12px;
  font-size: clamp(25px, 3.6vw, 40px);
  line-height: 1.15;
  font-weight: 900;
  letter-spacing: -0.02em;
  color: var(--paper);
}

.page-about .sec-head p {
  margin: 0;
  font-size: 15.5px;
  line-height: 1.78;
  color: var(--muted);
}

/* ---------- 时间线 ---------- */
.page-about .timeline {
  position: relative;
  display: grid;
  gap: clamp(18px, 2.6vw, 26px);
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .timeline::before {
  content: "";
  position: absolute;
  left: 9px;
  top: 8px;
  bottom: 8px;
  width: 2px;
  background: linear-gradient(180deg, var(--lime), var(--orange) 52%, var(--ice));
  opacity: 0.55;
}

.page-about .tl-item {
  position: relative;
  padding-left: 40px;
}

.page-about .tl-node {
  position: absolute;
  left: 0;
  top: 24px;
  width: 20px;
  height: 20px;
  border-radius: 50%;
  border: 3px solid var(--ink);
  background: var(--lime);
  box-shadow: 0 0 0 2px rgba(182, 255, 60, 0.3);
}

.page-about .tl-item:nth-child(2) .tl-node {
  background: var(--orange);
  box-shadow: 0 0 0 2px rgba(255, 138, 42, 0.32);
}

.page-about .tl-item:nth-child(3) .tl-node {
  background: var(--ice);
  box-shadow: 0 0 0 2px rgba(125, 211, 252, 0.32);
}

.page-about .tl-item:nth-child(4) .tl-node {
  background: var(--paper);
  box-shadow: 0 0 0 2px rgba(248, 250, 252, 0.28);
}

.page-about .tl-card {
  padding: clamp(16px, 2.4vw, 24px);
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  background: linear-gradient(140deg, rgba(30, 41, 59, 0.62), rgba(17, 24, 39, 0.9));
  box-shadow: var(--shadow-card);
}

.page-about .tl-era {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.18em;
  color: var(--lime);
}

.page-about .tl-card h3 {
  margin: 8px 0 10px;
  font-size: clamp(18px, 2.2vw, 22px);
  font-weight: 800;
  color: var(--paper);
}

.page-about .tl-card > p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.74;
  color: var(--muted);
}

/* ---------- 折叠面板 ---------- */
.page-about .fold {
  margin-top: 14px;
  padding: 10px 14px;
  border: 1px dashed var(--line);
  border-radius: var(--radius);
  background: rgba(10, 15, 31, 0.55);
}

.page-about .fold summary {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 13.5px;
  color: var(--ice);
  cursor: pointer;
  list-style: none;
}

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

.page-about .fold summary::before {
  content: "+";
  font-family: var(--font-mono);
  font-weight: 700;
  color: var(--lime);
}

.page-about .fold[open] summary::before {
  content: "\2013";
}

.page-about .fold-body {
  margin-top: 10px;
  font-size: 14px;
  line-height: 1.72;
  color: var(--muted);
}

.page-about .fold-body p {
  margin: 0 0 8px;
}

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

.page-about .fold-stack {
  display: grid;
  gap: 10px;
}

.page-about .fold-stack .fold {
  margin-top: 0;
}

/* ---------- 使用场景 ---------- */
.page-about .scene-layout {
  display: grid;
  gap: clamp(18px, 3vw, 30px);
}

.page-about .scene-cards {
  display: grid;
  gap: clamp(14px, 2vw, 20px);
}

.page-about .scene-card {
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding: clamp(18px, 2.6vw, 26px);
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  background: var(--ink-2);
}

.page-about .scene-card--desktop {
  border-top: 3px solid var(--lime);
}

.page-about .scene-card--mobile {
  border-top: 3px solid var(--orange);
}

.page-about .scene-card h3 {
  margin: 2px 0 0;
  font-size: clamp(18px, 2.2vw, 22px);
  font-weight: 800;
  color: var(--paper);
}

.page-about .scene-card p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.76;
  color: var(--muted);
}

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

/* ---------- 团队 ---------- */
.page-about .team-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
  margin-bottom: clamp(18px, 3vw, 28px);
}

.page-about .team-stat {
  padding: 18px 16px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: linear-gradient(150deg, rgba(30, 41, 59, 0.72), rgba(10, 15, 31, 0.9));
}

.page-about .team-stat .score {
  display: block;
  margin-bottom: 8px;
  font-family: var(--font-mono);
  font-size: clamp(28px, 4vw, 42px);
  font-weight: 700;
  line-height: 1;
  color: var(--lime);
}

.page-about .team-stat p {
  margin: 0;
  font-size: 13.5px;
  line-height: 1.55;
  color: var(--muted);
}

.page-about .rhythm {
  display: grid;
  gap: 12px;
  margin-bottom: clamp(18px, 3vw, 28px);
}

.page-about .rhythm-item {
  display: flex;
  align-items: baseline;
  gap: 14px;
  padding: 16px 18px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: rgba(30, 41, 59, 0.45);
}

.page-about .rhythm-time {
  flex: 0 0 auto;
  font-family: var(--font-mono);
  font-size: clamp(16px, 2.2vw, 22px);
  font-weight: 700;
  color: var(--orange);
  white-space: nowrap;
}

.page-about .rhythm-item p {
  margin: 0;
  font-size: 14px;
  line-height: 1.65;
  color: var(--paper);
}

/* ---------- 合作生态 ---------- */
.page-about .partner-layout {
  display: grid;
  gap: clamp(20px, 3vw, 34px);
}

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

.page-about .partner-body {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.page-about .partner-body p {
  margin: 0;
  font-size: 15px;
  line-height: 1.78;
  color: var(--about-soft);
}

.page-about .partner-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-bottom: 4px;
}

.page-about .partner-chip {
  position: relative;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 16px;
  border: 1px solid var(--line);
  border-radius: var(--pill);
  background: var(--ink-2);
  font-size: 13.5px;
  color: var(--paper);
  cursor: default;
  outline: none;
}

.page-about .partner-chip b {
  font-family: var(--font-mono);
  font-size: 15px;
  color: var(--lime);
}

.page-about .partner-chip::after {
  content: attr(data-note);
  position: absolute;
  left: 50%;
  bottom: calc(100% + 10px);
  z-index: 6;
  width: max-content;
  max-width: min(260px, 70vw);
  padding: 10px 12px;
  border-radius: var(--radius-sm);
  background: var(--paper);
  color: var(--ink);
  font-size: 12.5px;
  line-height: 1.55;
  text-align: left;
  white-space: normal;
  opacity: 0;
  pointer-events: none;
  transform: translate(-50%, 6px);
  transition: opacity 0.18s var(--ease), transform 0.18s var(--ease);
  box-shadow: 0 18px 36px -20px rgba(0, 0, 0, 0.95);
}

.page-about .partner-chip:hover::after,
.page-about .partner-chip:focus-visible::after {
  opacity: 1;
  transform: translate(-50%, 0);
}

.page-about .inline-link {
  color: var(--ice);
  text-decoration: underline;
  text-decoration-color: rgba(125, 211, 252, 0.45);
  text-underline-offset: 3px;
  transition: color 0.2s var(--ease);
}

.page-about .inline-link:hover {
  color: var(--lime);
}

/* ---------- 结尾入口 ---------- */
.page-about .about-cta {
  padding: clamp(30px, 5vw, 62px) 0;
}

.page-about .cta-shell {
  display: grid;
  gap: clamp(18px, 3vw, 30px);
  padding: clamp(22px, 3.8vw, 44px);
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  background: linear-gradient(120deg, rgba(182, 255, 60, 0.12), rgba(255, 138, 42, 0.1) 58%, rgba(125, 211, 252, 0.14));
}

.page-about .cta-shell h2 {
  margin: 0 0 10px;
  font-size: clamp(23px, 3.2vw, 36px);
  font-weight: 900;
  letter-spacing: -0.02em;
  color: var(--paper);
}

.page-about .cta-shell p {
  margin: 0;
  font-size: 15px;
  line-height: 1.76;
  color: var(--about-soft);
}

.page-about .cta-links {
  display: grid;
  gap: 10px;
}

.page-about .cta-link {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  padding: 15px 18px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: rgba(10, 15, 31, 0.62);
  font-size: 14.5px;
  color: var(--paper);
  text-decoration: none;
  transition: border-color 0.2s var(--ease), background 0.2s var(--ease), transform 0.2s var(--ease);
}

.page-about .cta-link:hover {
  border-color: var(--lime);
  background: rgba(182, 255, 60, 0.08);
  transform: translateX(3px);
}

.page-about .cta-arrow {
  font-family: var(--font-mono);
  color: var(--lime);
}

/* ---------- 响应式 ---------- */
@media (max-width: 699px) {
  .page-about .hero-vertical {
    display: none;
  }
}

@media (min-width: 700px) {
  .page-about .layer-list,
  .page-about .scene-cards,
  .page-about .rhythm {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

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

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

@media (min-width: 900px) {
  .page-about .hero-split {
    grid-template-columns: minmax(0, 1.55fr) minmax(260px, 0.72fr);
    align-items: end;
  }

  .page-about .about-grid {
    grid-template-columns: minmax(200px, 0.6fr) minmax(0, 1.4fr);
    align-items: start;
  }

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

@media (min-width: 940px) {
  .page-about .scene-layout {
    grid-template-columns: minmax(0, 1.24fr) minmax(280px, 0.76fr);
    align-items: start;
  }
}

@media (min-width: 1000px) {
  .page-about .cta-shell {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1.08fr);
    align-items: center;
  }
}