.page-about {
  --about-grid-line: rgba(232, 240, 254, 0.045);
  --about-glow-green: rgba(57, 255, 20, 0.12);
  --about-card-hover: #0D2143;
  background: var(--bg-primary);
  color: var(--text-primary);
  overflow-x: hidden;
}

.page-about .about-hero {
  position: relative;
  padding: 64px 0 48px;
  background:
    radial-gradient(circle at 78% 20%, rgba(57, 255, 20, 0.06), transparent 32%),
    linear-gradient(to right, var(--about-grid-line) 1px, transparent 1px),
    linear-gradient(to bottom, var(--about-grid-line) 1px, transparent 1px),
    linear-gradient(135deg, var(--bg-dark) 0%, var(--bg-primary) 42%, var(--bg-secondary) 100%);
  background-size: auto, 28px 28px, 28px 28px, auto;
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  top: 0;
  right: 14%;
  width: 160px;
  height: 4px;
  background: var(--accent-orange);
  transform: skewX(-30deg);
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  top: 24px;
  right: 5%;
  width: 260px;
  height: 260px;
  border: 1px solid rgba(57, 255, 20, 0.12);
  transform: rotate(45deg);
  pointer-events: none;
}

.page-about .about-hero-inner {
  display: grid;
  gap: 40px;
  align-items: center;
}

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

.page-about .about-hero-kicker {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.28em;
  color: var(--accent-orange);
  margin: 0 0 16px;
  text-transform: uppercase;
}

.page-about .about-hero-title {
  font-family: var(--font-sans);
  font-size: var(--fs-hero);
  font-weight: 900;
  line-height: 1.14;
  letter-spacing: 0.01em;
  margin: 0 0 18px;
  max-width: 660px;
  color: var(--text-primary);
}

.page-about .about-hero-desc {
  font-size: 17px;
  line-height: 1.75;
  color: var(--text-secondary);
  max-width: 560px;
  margin: 0;
}

.page-about .about-hero-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 12px 28px;
  margin: 28px 0 0;
  padding: 16px 0;
  border-top: 1px solid var(--border-blue);
  border-bottom: 1px solid var(--border-blue);
}

.page-about .about-hero-meta-item {
  font-size: 14px;
  color: var(--text-secondary);
  display: inline-flex;
  align-items: baseline;
  gap: 8px;
}

.page-about .about-hero-meta-item b {
  color: var(--accent-green);
  font-size: 18px;
  font-weight: 700;
}

.page-about .about-hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  margin-top: 28px;
}

.page-about .about-hero-visual {
  position: relative;
  z-index: 1;
  width: 100%;
  max-width: 440px;
  margin: 0 auto;
}

.page-about .about-hero-visual::after {
  content: "KAIYUN / 档案";
  position: absolute;
  left: -10px;
  bottom: -10px;
  z-index: 2;
  background: var(--accent-green);
  color: var(--bg-primary);
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 700;
  padding: 8px 12px;
  transform: skewX(-8deg);
}

.page-about .about-hero-visual img {
  display: block;
  width: 100%;
  height: auto;
  clip-path: polygon(0 0, 100% 0, 100% 92%, 92% 100%, 0 100%);
  background: var(--bg-secondary);
}

.page-about .about-archive {
  background:
    radial-gradient(circle at 10% 4%, rgba(57, 255, 20, 0.05), transparent 30%),
    linear-gradient(180deg, var(--bg-primary), var(--bg-secondary));
  padding: 40px 0 80px;
}

.page-about .about-archive-inner {
  display: grid;
  gap: 48px;
  align-items: start;
}

.page-about .about-index {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 4px 20px;
  padding: 16px 0;
  border-top: 2px solid var(--border-blue);
  border-bottom: 2px solid var(--border-blue);
}

.page-about .about-index-label {
  width: 100%;
  font-size: 12px;
  letter-spacing: 0.22em;
  color: var(--accent-orange);
  margin-bottom: 6px;
}

.page-about .about-index-link {
  color: var(--text-secondary);
  font-size: 14px;
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 0;
  border-bottom: 1px solid transparent;
}

.page-about .about-index-link .mono {
  font-size: 12px;
  color: var(--accent-green);
}

.page-about .about-index-link:hover,
.page-about .about-index-link:focus {
  color: var(--text-primary);
  border-bottom-color: var(--accent-orange);
}

.page-about .about-index-unit {
  width: 100%;
  margin: 12px 0 0;
  font-size: 12px;
  line-height: 1.7;
  color: var(--text-secondary);
  padding-left: 10px;
  border-left: 2px solid var(--accent-green);
}

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

.page-about .about-section {
  position: relative;
  scroll-margin-top: calc(var(--header-height) + 12px);
  padding: 56px 0;
  border-bottom: 1px solid var(--border-blue);
}

.page-about .about-section:last-child {
  border-bottom: none;
}

.page-about .about-section::before {
  content: attr(data-index);
  position: absolute;
  top: 12px;
  right: 4px;
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: clamp(48px, 8vw, 88px);
  line-height: 1;
  color: rgba(232, 240, 254, 0.035);
  pointer-events: none;
  z-index: 0;
}

.page-about .about-section-alt {
  background: rgba(18, 38, 77, 0.3);
  border-left: 2px solid var(--border-blue);
  padding-left: clamp(18px, 4vw, 40px);
  padding-right: clamp(18px, 4vw, 40px);
}

.page-about .about-section-dark {
  background: var(--bg-dark);
  border-left: 2px solid var(--border-blue);
  padding-left: clamp(18px, 4vw, 40px);
  padding-right: clamp(18px, 4vw, 40px);
}

.page-about .about-section-header {
  position: relative;
  z-index: 1;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 16px;
  margin-bottom: 28px;
}

.page-about .about-section-index {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  border: 1px solid var(--border-blue);
  color: var(--accent-orange);
  font-size: 14px;
  transform: skewX(-8deg);
}

.page-about .about-section-title {
  font-size: var(--fs-section);
  font-weight: 900;
  margin: 0;
  letter-spacing: 0.02em;
  color: var(--text-primary);
}

.page-about .about-section-lead {
  position: relative;
  z-index: 1;
  font-size: 20px;
  line-height: 1.65;
  color: var(--text-primary);
  max-width: 720px;
  margin: 0 0 24px;
}

.page-about .about-origin-body {
  max-width: 780px;
  position: relative;
  z-index: 1;
}

.page-about .about-origin-body p {
  line-height: 1.8;
  color: var(--text-secondary);
  margin: 0 0 18px;
}

.page-about .about-origin-quote {
  margin: 28px 0 0;
  padding: 24px 28px;
  background: var(--bg-secondary);
  border-left: 4px solid var(--accent-green);
  transform: skewX(-3deg);
}

.page-about .about-origin-quote p {
  margin: 0;
  font-size: 22px;
  font-weight: 900;
  color: var(--text-primary);
  transform: skewX(3deg);
  line-height: 1.3;
}

.page-about .about-origin-quote cite {
  display: block;
  margin-top: 8px;
  font-style: normal;
  font-size: 12px;
  color: var(--text-secondary);
  transform: skewX(3deg);
}

.page-about .about-idea-grid {
  display: grid;
  gap: 20px;
  margin-top: 32px;
  position: relative;
  z-index: 1;
}

.page-about .about-idea-card {
  padding: 30px 24px;
  background: var(--bg-secondary);
  clip-path: polygon(0 0, calc(100% - 18px) 0, 100% 18px, 100% 100%, 0 100%);
  border-right: 3px solid var(--border-blue);
  border-bottom: 1px solid var(--border-blue);
  transition: border-color var(--transition), background var(--transition);
}

.page-about .about-idea-card:hover {
  border-right-color: var(--accent-green);
  background: var(--about-card-hover);
}

.page-about .about-idea-num {
  display: block;
  margin-bottom: 18px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.18em;
  color: var(--accent-orange);
}

.page-about .about-idea-card h3 {
  margin: 0 0 12px;
  font-size: 20px;
  font-weight: 800;
  color: var(--text-primary);
}

.page-about .about-idea-card p {
  margin: 0;
  font-size: 14px;
  line-height: 1.75;
  color: var(--text-secondary);
}

.page-about .about-timeline-wrap {
  position: relative;
  z-index: 1;
  display: grid;
  gap: 40px;
}

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

.page-about .about-timeline::before {
  content: "";
  position: absolute;
  left: 6px;
  top: 4px;
  bottom: 4px;
  width: 2px;
  background: var(--border-blue);
}

.page-about .about-timeline-item {
  position: relative;
  padding: 0 0 48px 32px;
}

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

.page-about .about-timeline-item::before {
  content: "";
  position: absolute;
  left: 1px;
  top: 10px;
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--accent-green);
  box-shadow: 0 0 0 4px rgba(57, 255, 20, 0.14), 0 0 14px var(--about-glow-green);
  transition: background var(--transition), box-shadow var(--transition);
}

.page-about .about-timeline-year {
  display: block;
  margin-bottom: 8px;
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--accent-orange);
  letter-spacing: 0.12em;
}

.page-about .about-timeline-card {
  background: var(--bg-secondary);
  padding: 20px 20px 22px;
  border-left: 3px solid transparent;
  transition: border-color var(--transition), transform var(--transition), background var(--transition);
}

.page-about .about-timeline-card h3 {
  margin: 0 0 10px;
  font-size: 18px;
  font-weight: 800;
  color: var(--text-primary);
}

.page-about .about-timeline-card p {
  margin: 0 0 14px;
  font-size: 14px;
  line-height: 1.75;
  color: var(--text-secondary);
}

.page-about .about-timeline-detail {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 16px;
  font-size: 12px;
  color: var(--text-secondary);
}

.page-about .about-timeline-detail span {
  display: inline-flex;
  align-items: center;
  padding: 4px 10px;
  background: rgba(11, 27, 61, 0.6);
  border-left: 2px solid var(--accent-green);
}

.page-about .about-timeline-item:hover::before {
  background: var(--accent-orange);
  box-shadow: 0 0 0 4px rgba(255, 107, 0, 0.16), 0 0 16px rgba(255, 107, 0, 0.45);
}

.page-about .about-timeline-item:hover .about-timeline-card {
  border-left-color: var(--accent-green);
  transform: translateX(6px);
  background: var(--about-card-hover);
}

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

.page-about .about-timeline-figure img {
  display: block;
  width: 100%;
  height: auto;
  border: 1px solid var(--border-blue);
  background: var(--bg-secondary);
}

.page-about .about-timeline-figure figcaption {
  font-size: 12px;
  color: var(--text-secondary);
  padding-top: 10px;
  text-align: right;
}

.page-about .about-data-wrap {
  position: relative;
  z-index: 1;
  display: grid;
  gap: 32px;
}

.page-about .about-data-league {
  padding: 24px;
  background: var(--bg-secondary);
  border-left: 4px solid var(--accent-orange);
}

.page-about .about-data-league h3 {
  margin: 0 0 14px;
  font-size: 18px;
  color: var(--text-primary);
}

.page-about .about-data-list {
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .about-data-list li {
  padding: 10px 0;
  border-bottom: 1px solid var(--border-blue);
  font-size: 15px;
  color: var(--text-primary);
}

.page-about .about-data-list li:last-child {
  border-bottom: none;
}

.page-about .about-data-list .mono {
  display: inline-block;
  min-width: 44px;
  margin-right: 12px;
  color: var(--accent-green);
  font-size: 13px;
}

.page-about .about-data-panels {
  display: grid;
  gap: 16px;
  grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
}

.page-about .about-data-detail p {
  margin: 0 0 16px;
  line-height: 1.8;
  color: var(--text-secondary);
  max-width: 760px;
}

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

.page-about .about-data-figure img {
  display: block;
  width: 100%;
  height: auto;
  max-width: 640px;
  margin: 0 0 0 auto;
  border-left: 4px solid var(--accent-green);
}

.page-about .about-data-link {
  margin-top: 4px;
}

.page-about .about-team-grid {
  display: grid;
  gap: 20px;
  position: relative;
  z-index: 1;
}

.page-about .about-team-card {
  padding: 28px 24px;
  background: var(--bg-secondary);
  border-top: 3px solid var(--border-blue);
  border-bottom: 2px solid var(--border-blue);
  transition: border-color var(--transition), background var(--transition);
}

.page-about .about-team-card:hover {
  border-top-color: var(--accent-green);
  background: var(--about-card-hover);
}

.page-about .about-team-role {
  display: block;
  margin-bottom: 14px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.18em;
  color: var(--accent-orange);
}

.page-about .about-team-card h3 {
  margin: 0 0 12px;
  font-size: 18px;
  font-weight: 800;
  color: var(--text-primary);
}

.page-about .about-team-card p {
  margin: 0;
  font-size: 14px;
  line-height: 1.7;
  color: var(--text-secondary);
}

.page-about .about-team-card ul {
  margin: 16px 0 0;
  padding: 16px 0 0;
  list-style: none;
  border-top: 1px solid var(--border-blue);
}

.page-about .about-team-card li {
  font-size: 13px;
  color: var(--text-secondary);
  line-height: 1.8;
}

.page-about .about-team-card li::before {
  content: "/";
  color: var(--accent-green);
  margin-right: 8px;
  font-family: var(--font-mono);
}

.page-about .about-team-note {
  position: relative;
  z-index: 1;
  margin: 28px 0 0;
  font-size: 14px;
  line-height: 1.8;
  color: var(--text-secondary);
  max-width: 760px;
}

.page-about .about-team-note + .btn {
  margin-top: 20px;
}

.page-about .about-promise-list {
  display: grid;
  gap: 20px;
  position: relative;
  z-index: 1;
}

.page-about .about-promise-item {
  padding: 24px 24px 26px;
  background: var(--bg-secondary);
  border-right: 3px solid var(--border-blue);
  border-left: 4px solid var(--accent-green);
}

.page-about .about-promise-item h3 {
  margin: 0 0 10px;
  font-size: 18px;
  font-weight: 800;
  color: var(--text-primary);
}

.page-about .about-promise-item p {
  margin: 0;
  font-size: 14px;
  line-height: 1.7;
  color: var(--text-secondary);
}

.page-about .about-promise-note {
  position: relative;
  z-index: 1;
  margin: 28px 0 0;
  font-size: 14px;
  line-height: 1.8;
  color: var(--text-secondary);
  max-width: 760px;
}

.page-about .about-promise-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  margin-top: 28px;
  position: relative;
  z-index: 1;
}

@media (min-width: 760px) {
  .page-about .about-idea-grid {
    grid-template-columns: repeat(3, 1fr);
  }

  .page-about .about-timeline-wrap {
    grid-template-columns: 1fr;
  }

  .page-about .about-timeline-item {
    padding-left: 0;
    display: grid;
    grid-template-columns: 120px 1fr;
    gap: 28px;
  }

  .page-about .about-timeline::before {
    left: 120px;
  }

  .page-about .about-timeline-item::before {
    left: 115px;
  }

  .page-about .about-timeline-year {
    text-align: right;
    margin: 0;
    padding-top: 12px;
  }

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

  .page-about .about-promise-list {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 960px) {
  .page-about .about-hero-inner {
    grid-template-columns: 1.1fr 0.9fr;
  }

  .page-about .about-hero-visual {
    justify-self: end;
  }
}

@media (min-width: 1024px) {
  .page-about .about-archive-inner {
    grid-template-columns: 250px 1fr;
    gap: 64px;
  }

  .page-about .about-index {
    position: sticky;
    top: calc(var(--header-height) + 24px);
    display: block;
    border: none;
    border-left: 2px solid var(--border-blue);
    padding: 12px 0 12px 24px;
    margin-top: 8px;
  }

  .page-about .about-index-link {
    display: block;
    padding: 10px 0;
    width: 100%;
  }

  .page-about .about-index-unit {
    width: auto;
  }
}