.page-about {
  --about-cut: 18px;
  --about-rail: 220px;
  --about-gap: clamp(20px, 3vw, 32px);
  overflow-x: clip;
  padding-bottom: 80px;
}

.page-about .breadcrumb {
  margin-top: 18px;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  isolation: isolate;
  padding: 26px 0 6px;
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  background:
    radial-gradient(700px 420px at 84% 6%, rgba(55, 226, 213, .10), transparent 68%),
    radial-gradient(560px 360px at 6% 94%, rgba(255, 138, 61, .08), transparent 70%);
}

.page-about .about-hero__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--about-gap);
  align-items: start;
}

.page-about .about-hero__text {
  min-width: 0;
}

.page-about .about-hero h1 {
  margin: 14px 0 0;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(38px, 8.4vw, 66px);
  line-height: 1.04;
  letter-spacing: -0.02em;
  color: var(--paper);
}

.page-about .about-hero__lede {
  margin: 22px 0 0;
  max-width: 48ch;
  font-size: 17px;
  line-height: 1.85;
  color: var(--paper);
}

.page-about .about-hero__sub {
  margin: 14px 0 0;
  max-width: 48ch;
  font-size: 15px;
  line-height: 1.8;
  color: var(--muted);
}

.page-about .about-hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 28px;
}

.page-about .about-hero__figure {
  margin: 0;
  overflow: hidden;
  background: var(--ink-800);
  border: 1px solid var(--line);
  clip-path: polygon(0 0, calc(100% - var(--about-cut)) 0, 100% var(--about-cut), 100% 100%, var(--about-cut) 100%, 0 calc(100% - var(--about-cut)));
}

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

/* ---------- 数据条 ---------- */
.page-about .about-facts {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  margin: 40px 0 0;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.page-about .about-fact {
  padding: 18px 14px 18px 16px;
  border-left: 1px solid var(--line-soft);
}

.page-about .about-fact:first-child,
.page-about .about-fact:nth-child(odd) {
  border-left: 0;
  padding-left: 0;
}

.page-about .about-fact dt {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .06em;
  color: var(--muted);
}

.page-about .about-fact dd {
  margin: 8px 0 0;
  font-family: var(--font-display);
  font-size: 21px;
  font-weight: 700;
  line-height: 1.2;
  color: var(--paper);
}

.page-about .about-fact dd .mono {
  color: var(--cyan);
}

/* ---------- 主布局 ---------- */
.page-about .about-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 6px;
  margin-top: 48px;
}

.page-about .about-index {
  min-width: 0;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--line);
}

.page-about .about-index .eyebrow {
  margin: 0 0 10px;
}

.page-about .about-index ol {
  display: flex;
  gap: 8px;
  margin: 0;
  padding: 0 0 8px;
  list-style: none;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  scrollbar-width: thin;
}

.page-about .about-index a {
  display: inline-flex;
  align-items: baseline;
  gap: 8px;
  white-space: nowrap;
  padding: 8px 14px;
  font-size: 14px;
  line-height: 1.4;
  color: var(--muted);
  text-decoration: none;
  border: 1px solid var(--line);
  border-radius: 999px;
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease), background-color var(--dur) var(--ease);
}

.page-about .about-index a .mono {
  font-size: 11px;
  letter-spacing: .08em;
  color: var(--cyan);
}

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

.page-about .about-index a[aria-current="true"],
.page-about .about-index a[aria-current="page"] {
  color: var(--paper);
  border-color: var(--orange);
  background: rgba(255, 138, 61, .12);
}

/* ---------- 章节 ---------- */
.page-about .about-content {
  min-width: 0;
}

.page-about .about-section {
  padding: 40px 0;
  border-top: 1px solid var(--line);
}

.page-about .about-section:first-child {
  border-top: 0;
  padding-top: 32px;
}

.page-about .about-section h2 {
  margin: 0 0 18px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(24px, 3.6vw, 32px);
  line-height: 1.24;
  letter-spacing: -0.01em;
  color: var(--paper);
}

.page-about .about-section h3 {
  margin: 0 0 8px;
  font-size: 17px;
  font-weight: 600;
  line-height: 1.5;
  color: var(--paper);
}

.page-about .about-section p {
  margin: 0 0 16px;
  font-size: 16px;
  line-height: 1.85;
  color: var(--muted);
}

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

.page-about .about-content p a,
.page-about .about-content li a {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(55, 226, 213, .35);
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.page-about .about-content p a:hover,
.page-about .about-content li a:hover {
  color: var(--cyan-soft);
  border-bottom-color: var(--cyan-soft);
}

.page-about .pullquote {
  margin: 26px 0 0;
  padding: 6px 0 6px 20px;
  border-left: 3px solid var(--orange);
  font-size: 18px;
  line-height: 1.8;
  color: var(--paper);
}

/* ---------- 三个分区 ---------- */
.page-about .zone-list {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 14px;
  margin: 22px 0 0;
  padding: 0;
  list-style: none;
}

.page-about .zone {
  padding: 20px 18px;
  background: var(--ink-800);
  border: 1px solid var(--line);
  clip-path: polygon(0 0, calc(100% - 14px) 0, 100% 14px, 100% 100%, 0 100%);
}

.page-about .zone__num {
  margin: 0 0 10px;
  font-size: 11px;
  letter-spacing: .08em;
  color: var(--cyan);
}

.page-about .zone p {
  font-size: 15px;
  line-height: 1.8;
}

/* ---------- 值班 ---------- */
.page-about .duty-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 16px;
  margin-top: 22px;
}

.page-about .duty-card {
  position: relative;
  padding: 24px 20px 20px;
  background: var(--ink-800);
  border: 1px solid var(--line);
}

.page-about .duty-card::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  width: 56px;
  height: 3px;
  background: var(--cyan);
}

.page-about .duty-card:last-child::before {
  background: var(--orange);
}

.page-about .duty-card__label {
  margin: 0 0 10px;
  font-size: 11px;
  letter-spacing: .08em;
  color: var(--muted);
}

.page-about .duty-figure {
  margin: 26px 0 0;
  border: 1px solid var(--line);
  background: var(--ink-800);
}

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

.page-about .duty-figure figcaption {
  padding: 12px 16px;
  font-size: 13px;
  line-height: 1.7;
  color: var(--muted);
  border-top: 1px solid var(--line-soft);
}

/* ---------- 时间线 ---------- */
.page-about .timeline-figure {
  margin: 22px 0 30px;
  border: 1px solid var(--line);
  background: var(--ink-800);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 16px), calc(100% - 16px) 100%, 0 100%);
  overflow: hidden;
}

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

.page-about .timeline {
  position: relative;
  margin: 0;
  padding: 0 0 0 36px;
  list-style: none;
}

.page-about .timeline::before {
  content: "";
  position: absolute;
  left: 8px;
  top: 10px;
  bottom: 10px;
  width: 1px;
  background: var(--line);
}

.page-about .tl-item {
  position: relative;
  padding-bottom: 26px;
}

.page-about .tl-item:last-child {
  padding-bottom: 0;
}

.page-about .tl-item::before {
  content: "";
  position: absolute;
  left: -36px;
  top: 6px;
  width: 11px;
  height: 11px;
  border: 2px solid var(--cyan);
  border-radius: 50%;
  background: var(--ink-900);
  transition: background-color var(--dur) var(--ease), box-shadow var(--dur) var(--ease);
}

.page-about .tl-item--now::before {
  border-color: var(--orange);
  box-shadow: 0 0 0 5px rgba(255, 138, 61, .16);
}

.page-about .tl-item:hover::before {
  background: var(--cyan);
  box-shadow: 0 0 0 5px rgba(55, 226, 213, .16);
}

.page-about .tl-item--now:hover::before {
  background: var(--orange);
  box-shadow: 0 0 0 5px rgba(255, 138, 61, .24);
}

.page-about .tl-title {
  margin: 0;
  font-size: 16px;
  font-weight: 600;
  line-height: 1.6;
  color: var(--paper);
}

.page-about .tl-note {
  margin: 6px 0 0;
  max-width: 56ch;
  font-size: 14px;
  line-height: 1.8;
  color: var(--muted);
  opacity: 0;
  visibility: hidden;
  transform: translateY(-4px);
  transition: opacity var(--dur) var(--ease), transform var(--dur) var(--ease), visibility var(--dur) var(--ease);
}

.page-about .tl-item:hover .tl-note,
.page-about .tl-item:focus-within .tl-note {
  opacity: 1;
  visibility: visible;
  transform: none;
}

/* ---------- 规则步骤 ---------- */
.page-about .step-list {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 12px;
  margin: 22px 0 0;
  padding: 0;
  list-style: none;
}

.page-about .step {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 6px;
  padding: 16px 18px;
  background: var(--ink-800);
  border-left: 2px solid var(--line);
}

.page-about .step__i {
  font-size: 11px;
  letter-spacing: .08em;
  color: var(--cyan);
}

.page-about .step p {
  font-size: 15px;
  line-height: 1.8;
}

/* ---------- 三条原则 ---------- */
.page-about .principle-list {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 16px;
  margin-top: 22px;
}

.page-about .principle {
  padding: 24px 20px 14px;
  background: var(--ink-800);
  border: 1px solid var(--line);
  clip-path: polygon(0 0, calc(100% - 16px) 0, 100% 16px, 100% 100%, 0 100%);
  transition: transform var(--dur) var(--ease), box-shadow var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.page-about .principle:hover,
.page-about .principle:focus-within {
  transform: translateY(-4px);
  border-color: var(--cyan);
  box-shadow: 0 18px 38px rgba(4, 12, 22, .45);
}

.page-about .principle__num {
  margin: 0 0 12px;
  font-size: 11px;
  letter-spacing: .08em;
  color: var(--orange);
}

.page-about .principle p {
  font-size: 15px;
  line-height: 1.8;
}

.page-about .principle details {
  margin-top: 14px;
  border-top: 1px solid var(--line-soft);
}

.page-about .principle summary {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 14px 0;
  cursor: pointer;
  list-style: none;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .06em;
  color: var(--cyan);
}

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

.page-about .principle summary::after {
  content: "+";
  font-size: 14px;
  line-height: 1;
  transition: transform var(--dur) var(--ease);
}

.page-about .principle details[open] summary::after {
  transform: rotate(45deg);
}

.page-about .principle summary:hover {
  color: var(--cyan-soft);
}

.page-about .principle details p {
  padding-bottom: 14px;
  font-size: 14px;
  color: var(--muted);
}

/* ---------- 会合 ---------- */
.page-about .meet-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 14px;
  margin-top: 22px;
}

.page-about .meet-card {
  padding: 20px 18px;
  background: var(--ink-800);
  border: 1px solid var(--line);
}

.page-about .meet-card__label {
  margin: 0;
  font-size: 11px;
  letter-spacing: .08em;
  color: var(--muted);
}

.page-about .meet-card__value {
  margin: 10px 0 0;
  font-size: 16px;
  line-height: 1.7;
  color: var(--paper);
  overflow-wrap: anywhere;
}

.page-about .meet-note {
  margin-top: 20px;
  font-size: 15px;
}

.page-about .meet-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 24px;
}

/* ---------- 断点 ---------- */
@media (min-width: 640px) {
  .page-about .zone-list {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

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

  .page-about .about-fact {
    border-left: 1px solid var(--line-soft);
    padding-left: 18px;
  }

  .page-about .about-fact:first-child {
    border-left: 0;
    padding-left: 0;
  }
}

@media (min-width: 768px) {
  .page-about .about-facts {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .about-fact:nth-child(odd) {
    border-left: 1px solid var(--line-soft);
    padding-left: 18px;
  }

  .page-about .about-fact:first-child {
    border-left: 0;
    padding-left: 0;
  }

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

  .page-about .step {
    grid-template-columns: 92px minmax(0, 1fr);
    align-items: baseline;
    gap: 14px;
  }
}

@media (min-width: 900px) {
  .page-about .about-hero {
    padding: 40px 0 12px;
  }

  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, .95fr);
    gap: 56px;
  }

  .page-about .about-facts {
    margin-top: 56px;
  }
}

@media (min-width: 1024px) {
  .page-about {
    padding-bottom: 104px;
  }

  .page-about .about-layout {
    grid-template-columns: var(--about-rail) minmax(0, 1fr);
    gap: 56px;
    margin-top: 72px;
  }

  .page-about .about-index {
    position: sticky;
    top: 104px;
    align-self: start;
    padding-bottom: 0;
    border-bottom: 0;
  }

  .page-about .about-index ol {
    flex-direction: column;
    gap: 0;
    overflow: visible;
    padding-bottom: 0;
    border-left: 1px solid var(--line);
  }

  .page-about .about-index a {
    border: 0;
    border-left: 2px solid transparent;
    border-radius: 0;
    margin-left: -1px;
    padding: 9px 12px;
    font-size: 13.5px;
  }

  .page-about .about-index a[aria-current="true"],
  .page-about .about-index a[aria-current="page"] {
    border-left-color: var(--orange);
    background: linear-gradient(90deg, rgba(255, 138, 61, .14), transparent 72%);
  }

  .page-about .about-section {
    padding: 48px 0;
  }

  .page-about .about-section:first-child {
    padding-top: 0;
  }

  .page-about .duty-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 20px;
  }

  .page-about .principle-list {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 20px;
  }

  .page-about .tl-note {
    opacity: 0;
    visibility: hidden;
  }
}

@media (max-width: 1023px) {
  .page-about .tl-note {
    opacity: 1;
    visibility: visible;
    transform: none;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about * {
    transition-duration: .01ms !important;
    animation-duration: .01ms !important;
  }

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