.page-about {
  --about-cut: polygon(14px 0, 100% 0, 100% calc(100% - 14px), calc(100% - 14px) 100%, 0 100%, 0 14px);
  --about-rail-w: 208px;
  background: var(--ink);
  color: var(--paper);
  padding-bottom: clamp(56px, 8vw, 104px);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  padding: clamp(26px, 4.4vw, 54px) 0 clamp(30px, 5vw, 62px);
  background-color: var(--ink);
  background-image:
    radial-gradient(85% 130% at 92% -25%, rgba(37, 232, 201, 0.15), transparent 62%),
    radial-gradient(70% 120% at 2% 120%, rgba(255, 138, 61, 0.10), transparent 60%),
    repeating-linear-gradient(90deg, rgba(46, 58, 94, 0.38) 0 1px, transparent 1px 86px);
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 3px;
  background: linear-gradient(90deg, transparent, var(--cyan) 42%, var(--orange) 92%);
  transform: skewY(-0.6deg);
  transform-origin: left center;
  pointer-events: none;
}

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

.page-about .about-hero .crumb {
  margin-bottom: 20px;
}

.page-about .about-title {
  margin: 10px 0 0;
  max-width: 15em;
  font-family: var(--font-head);
  font-size: clamp(34px, 6.2vw, 66px);
  font-weight: 800;
  line-height: 1.04;
  letter-spacing: -0.02em;
  color: var(--paper);
}

.page-about .about-lede {
  margin: 18px 0 0;
  max-width: 56ch;
  padding-left: 18px;
  border-left: 2px solid var(--cyan);
  font-family: var(--font-body);
  font-size: clamp(16px, 1.9vw, 18px);
  line-height: 1.78;
  color: var(--mist);
}

.page-about .about-facts {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
  margin: 28px 0 0;
  padding: 0;
  list-style: none;
}

.page-about .fact {
  padding: 14px 16px;
  border: 1px solid var(--line);
  background: var(--ink-2);
  clip-path: var(--about-cut);
}

.page-about .fact-num {
  display: block;
  font-family: var(--font-num);
  font-size: clamp(22px, 3vw, 28px);
  line-height: 1.2;
  color: var(--cyan);
  font-variant-numeric: tabular-nums;
}

.page-about .fact-label {
  display: block;
  margin-top: 6px;
  font-size: 13px;
  line-height: 1.55;
  color: var(--mist);
}

/* ---------- 主体栏栅 ---------- */
.page-about .about-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 28px;
  padding-top: clamp(28px, 4vw, 52px);
}

/* 章节轨道 */
.page-about .about-rail {
  overflow-x: auto;
  overflow-y: hidden;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--line);
  scrollbar-width: none;
}

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

.page-about .rail-track {
  display: flex;
  gap: 8px;
  min-width: max-content;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .rail-link {
  display: flex;
  align-items: baseline;
  gap: 9px;
  padding: 9px 12px;
  border: 1px solid transparent;
  color: var(--mist);
  font-size: 14px;
  line-height: 1.3;
  text-decoration: none;
  white-space: nowrap;
  transition: color var(--dur) var(--ease), background-color var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.page-about .rail-num {
  font-family: var(--font-num);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--orange);
}

.page-about .rail-link:hover,
.page-about .rail-link:focus-visible {
  color: var(--cyan);
  background: var(--ink-2);
  border-color: var(--line);
}

/* ---------- 内容流 ---------- */
.page-about .about-stream {
  display: grid;
  gap: clamp(40px, 6vw, 72px);
}

.page-about .about-chapter {
  position: relative;
  scroll-margin-top: 112px;
}

.page-about .chapter-head {
  position: relative;
  display: flex;
  align-items: baseline;
  gap: 14px;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--line);
}

.page-about .chapter-head::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: -1px;
  width: 68px;
  height: 2px;
  background: linear-gradient(90deg, var(--cyan), var(--orange));
}

.page-about .chapter-num {
  font-family: var(--font-num);
  font-size: 13px;
  letter-spacing: 0.1em;
  color: var(--orange);
}

.page-about .chapter-title {
  margin: 0;
  font-family: var(--font-head);
  font-size: clamp(24px, 3.4vw, 38px);
  font-weight: 700;
  line-height: 1.18;
  letter-spacing: -0.01em;
  color: var(--paper);
}

.page-about .story-panel {
  margin-top: 22px;
  padding: clamp(20px, 3vw, 34px);
  background: var(--cream);
  color: var(--brown);
  clip-path: var(--about-cut);
  font-family: var(--font-body);
  font-size: 16.5px;
  line-height: 1.82;
}

.page-about .story-panel p {
  margin: 0;
}

.page-about .story-panel p + p {
  margin-top: 16px;
}

.page-about .story-panel a {
  color: var(--rust);
  font-weight: 600;
  text-decoration: underline;
  text-underline-offset: 3px;
}

.page-about .chapter-foot {
  margin: 16px 0 0;
  font-size: 15px;
  line-height: 1.7;
  color: var(--mist);
}

.page-about .chapter-foot a {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px dashed var(--line);
  padding-bottom: 1px;
}

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

/* ---------- 使用场景 ---------- */
.page-about .about-scenes {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 14px;
  margin: 22px 0 0;
  padding: 0;
  list-style: none;
}

.page-about .scene {
  padding: 18px;
  border: 1px solid var(--line);
  background: var(--ink-2);
  clip-path: var(--about-cut);
  transition: transform var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.page-about .scene:hover {
  transform: translateY(-2px);
  border-color: var(--cyan);
}

.page-about .scene-title {
  margin: 0 0 8px;
  font-family: var(--font-head);
  font-size: 18px;
  font-weight: 700;
  line-height: 1.3;
  color: var(--paper);
}

.page-about .scene-text {
  margin: 0;
  font-size: 15px;
  line-height: 1.72;
  color: var(--mist);
}

/* ---------- 配图 ---------- */
.page-about .about-figure {
  margin: 22px 0 0;
  padding: 0;
  border: 1px solid var(--line);
  background: var(--ink-2);
  clip-path: var(--about-cut);
  overflow: hidden;
}

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

.page-about .about-figure .media-caption {
  padding: 12px 16px 14px;
  border-top: 1px solid var(--line);
  font-size: 13px;
  line-height: 1.62;
  color: var(--mist);
}

/* ---------- 数据侧栏 ---------- */
.page-about .side-note {
  margin-top: 18px;
  padding: 18px 20px;
  border-left: 2px solid var(--cyan);
  background: var(--ink-2);
}

.page-about .side-note-title {
  margin: 0 0 12px;
  font-family: var(--font-head);
  font-size: 17px;
  font-weight: 700;
  color: var(--paper);
}

.page-about .side-list {
  display: grid;
  gap: 9px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .side-list li {
  position: relative;
  padding-left: 15px;
  font-size: 14.5px;
  line-height: 1.7;
  color: var(--mist);
}

.page-about .side-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.65em;
  width: 6px;
  height: 6px;
  background: var(--orange);
  transform: rotate(45deg);
}

/* ---------- 三件具体事 ---------- */
.page-about .pillar-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 14px;
  margin-top: 22px;
}

.page-about .pillar {
  padding: 22px 20px 24px;
  border: 1px solid var(--line);
  background: linear-gradient(160deg, var(--ink-2), var(--ink-3));
  clip-path: var(--about-cut);
  transition: transform var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.page-about .pillar:hover {
  transform: translateY(-2px);
  border-color: var(--cyan);
}

.page-about .pillar-num {
  font-family: var(--font-num);
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--rust);
}

.page-about .pillar-title {
  margin: 8px 0 10px;
  font-family: var(--font-head);
  font-size: 22px;
  font-weight: 700;
  line-height: 1.25;
  color: var(--paper);
}

.page-about .pillar-text {
  margin: 0;
  font-size: 15px;
  line-height: 1.76;
  color: var(--mist);
}

/* ---------- 团队 ---------- */
.page-about .team-split {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 18px;
  margin-top: 22px;
}

.page-about .team-split .about-figure {
  margin-top: 0;
}

.page-about .about-details {
  padding: 16px 18px;
  border: 1px solid var(--line);
  background: var(--ink-2);
  clip-path: var(--about-cut);
}

.page-about .details-summary {
  cursor: pointer;
  list-style: none;
  font-family: var(--font-head);
  font-size: 17px;
  font-weight: 700;
  color: var(--cyan);
}

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

.page-about .details-summary::after {
  content: "＋";
  float: right;
  font-family: var(--font-num);
  font-size: 15px;
  color: var(--orange);
}

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

.page-about .details-summary:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 4px;
}

.page-about .details-list {
  display: grid;
  gap: 11px;
  margin: 14px 0 0;
  padding: 0;
  list-style: none;
}

.page-about .details-list li {
  position: relative;
  padding-left: 15px;
  font-size: 14.5px;
  line-height: 1.7;
  color: var(--mist);
}

.page-about .details-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.65em;
  width: 6px;
  height: 6px;
  background: var(--cyan);
  transform: rotate(45deg);
}

.page-about .details-list strong {
  margin-right: 4px;
  color: var(--paper);
  font-weight: 600;
}

/* ---------- 三个阶段 ---------- */
.page-about .stage-list {
  margin: 26px 0 0;
  padding: 0;
  list-style: none;
}

.page-about .stage {
  position: relative;
  padding: 0 0 28px 30px;
  border-left: 1px solid var(--line);
}

.page-about .stage:last-child {
  padding-bottom: 0;
  border-left-color: transparent;
}

.page-about .stage::before {
  content: "";
  position: absolute;
  left: -6px;
  top: 5px;
  width: 11px;
  height: 11px;
  background: var(--ink);
  border: 2px solid var(--cyan);
  transform: rotate(45deg);
}

.page-about .stage:last-child::before {
  background: var(--orange);
  border-color: var(--orange);
}

.page-about .stage-tag {
  font-family: var(--font-num);
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--orange);
}

.page-about .stage-title {
  margin: 6px 0 8px;
  font-family: var(--font-head);
  font-size: 21px;
  font-weight: 700;
  line-height: 1.3;
  color: var(--paper);
}

.page-about .stage-text {
  margin: 0;
  max-width: 62ch;
  font-size: 15.5px;
  line-height: 1.8;
  color: var(--mist);
}

/* ---------- 支持与联系 ---------- */
.page-about .support-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 14px;
  margin-top: 22px;
}

.page-about .support-card {
  padding: 20px;
  background: var(--cream);
  color: var(--brown);
  clip-path: var(--about-cut);
}

.page-about .support-title {
  margin: 0 0 10px;
  font-family: var(--font-head);
  font-size: 19px;
  font-weight: 700;
  line-height: 1.3;
  color: var(--brown);
}

.page-about .support-title::before {
  content: "";
  display: block;
  width: 28px;
  height: 3px;
  margin-bottom: 12px;
  background: var(--rust);
}

.page-about .support-text {
  margin: 0;
  font-size: 15px;
  line-height: 1.78;
  color: var(--brown);
}

.page-about .support-contact {
  margin-top: 22px;
  padding: 20px clamp(18px, 2.6vw, 26px);
  border: 1px solid var(--line);
  background: var(--ink-2);
  clip-path: var(--about-cut);
}

.page-about .support-line {
  margin: 0;
  font-size: 15.5px;
  line-height: 1.7;
  color: var(--paper);
}

.page-about .support-line + .support-line {
  margin-top: 8px;
}

.page-about .support-line--muted {
  font-size: 14px;
  color: var(--mist);
}

.page-about .support-actions {
  margin-top: 20px;
}

/* ---------- 响应式 ---------- */
@media (min-width: 720px) {
  .page-about .about-facts {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

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

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

@media (min-width: 800px) {
  .page-about .pillar-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

@media (min-width: 880px) {
  .page-about .team-split {
    grid-template-columns: minmax(0, 1.25fr) minmax(0, 1fr);
    align-items: start;
  }
}

@media (min-width: 980px) {
  .page-about .about-layout {
    grid-template-columns: var(--about-rail-w) minmax(0, 1fr);
    gap: 48px;
    align-items: start;
  }

  .page-about .about-rail {
    position: sticky;
    top: 116px;
    overflow: visible;
    padding: 4px 0 0;
    border-bottom: none;
    border-left: 1px solid var(--line);
  }

  .page-about .rail-track {
    flex-direction: column;
    gap: 2px;
    min-width: 0;
  }

  .page-about .rail-link {
    white-space: normal;
    padding: 10px 14px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .scene,
  .page-about .pillar,
  .page-about .rail-link {
    transition: none;
  }

  .page-about .scene:hover,
  .page-about .pillar:hover {
    transform: none;
  }
}