.page-about {
  position: relative;
  overflow-x: hidden;
  background-color: var(--x-bg-dark);
  background-image:
    linear-gradient(rgba(30, 41, 59, 0.45) 1px, transparent 1px),
    linear-gradient(90deg, rgba(30, 41, 59, 0.45) 1px, transparent 1px);
  background-size: 40px 40px;
}

.page-about__context {
  padding-top: 1.5rem;
}

.page-about__hero {
  padding: 3rem 0 2.25rem;
}

.page-about__hero-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 2.5rem;
  align-items: center;
}

.page-about__hero-copy h1 {
  margin: 1rem 0 1.25rem;
  font-size: 2.125rem;
  line-height: 1.12;
  letter-spacing: -0.02em;
  color: var(--x-text-light);
}

.page-about__hero-highlight {
  display: block;
  position: relative;
  color: var(--x-neon-green);
}

.page-about__hero-highlight::after {
  content: '';
  position: absolute;
  left: 0;
  bottom: 0.125rem;
  height: 3px;
  width: 100%;
  background: linear-gradient(90deg, var(--x-orange) 0%, transparent 92%);
  transform: skewX(-18deg);
}

.page-about__hero-desc {
  max-width: 34rem;
  margin: 0 0 1.75rem;
  color: rgba(226, 232, 240, 0.85);
  font-size: 1.0625rem;
  line-height: 1.7;
}

.page-about__hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.875rem;
}

.page-about__hero-visual {
  position: relative;
}

.page-about__hero-visual .hb-img-frame {
  border: 1px solid var(--x-card);
  box-shadow: 14px 14px 0 rgba(100, 255, 218, 0.06);
}

.page-about__hero-meta {
  display: flex;
  justify-content: space-between;
  padding: 0.75rem 0.25rem 0;
  font-family: var(--x-font-mono);
  font-size: 0.75rem;
  color: var(--x-neon-green);
  letter-spacing: 0.03em;
}

.page-about__stat-strip {
  border-top: 1px solid rgba(30, 41, 59, 0.8);
  border-bottom: 1px solid rgba(30, 41, 59, 0.8);
  background: rgba(10, 25, 47, 0.6);
}

.page-about__stat-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1.5rem 1rem;
  padding: 1.5rem 0;
}

.page-about .hb-stat__value {
  display: block;
  margin-bottom: 0.25rem;
  font-family: var(--x-font-mono);
  font-size: 1.75rem;
  line-height: 1.1;
  font-weight: 700;
  color: var(--x-neon-green);
}

.page-about .hb-stat__label {
  font-size: 0.8125rem;
  line-height: 1.5;
  color: rgba(226, 232, 240, 0.72);
}

.page-about__layout {
  padding-top: 4rem;
  padding-bottom: 4rem;
}

.page-about__layout-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 2rem;
}

.page-about__toc-inner {
  padding: 1.25rem 1rem;
  border: 1px solid var(--x-card);
  border-radius: var(--x-radius);
  background: rgba(10, 25, 47, 0.8);
}

.page-about__toc-list {
  list-style: none;
  margin: 1rem 0 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
}

.page-about__toc-link {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding: 0.625rem 0.875rem;
  color: rgba(226, 232, 240, 0.78);
  text-decoration: none;
  font-family: var(--x-font-mono);
  font-size: 0.875rem;
  border: 1px solid transparent;
  border-left: 2px solid var(--x-line-grid);
  transition: border-color 0.2s, background-color 0.2s, color 0.2s;
}

.page-about__toc-num {
  color: var(--x-orange);
  font-size: 0.75rem;
}

.page-about__toc-link:hover,
.page-about__toc-link.is-current {
  border-left-color: var(--x-orange);
  background: rgba(100, 255, 218, 0.06);
  color: var(--x-neon-green);
}

.page-about__toc-note {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  margin-top: 1.25rem;
  padding: 0.625rem 0.875rem;
  background: rgba(100, 255, 218, 0.05);
  font-family: var(--x-font-mono);
  font-size: 0.75rem;
  color: rgba(226, 232, 240, 0.85);
}

.page-about__chapter {
  position: relative;
  padding: 2rem 1.25rem 2.5rem;
  margin-bottom: 2rem;
  border: 1px solid var(--x-card);
  border-radius: var(--x-radius);
  background: rgba(11, 17, 32, 0.82);
  scroll-margin-top: 7rem;
}

.page-about__chapter::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 2px;
  background: linear-gradient(90deg, var(--x-orange) 0%, var(--x-neon-green) 100%);
  opacity: 0.55;
}

.page-about__chapter > h2 {
  margin: 0.5rem 0 0.75rem;
  font-size: 1.75rem;
  line-height: 1.2;
  letter-spacing: -0.01em;
  color: var(--x-text-light);
}

.page-about__lead {
  margin-bottom: 1.5rem;
  color: rgba(226, 232, 240, 0.85);
  font-size: 1.0625rem;
  line-height: 1.7;
}

.page-about__chapter p {
  color: rgba(226, 232, 240, 0.78);
  line-height: 1.7;
  margin: 0 0 1rem;
}

.page-about__pull {
  margin: 1.5rem 0;
  padding-left: 1rem;
  border-left: 3px solid var(--x-orange);
  color: var(--x-neon-green);
  font-weight: 700;
  font-size: 1.0625rem;
  line-height: 1.5;
}

.page-about__origin-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.5rem;
  margin-top: 0.5rem;
}

.page-about__origin-aside .hb-panel {
  margin-bottom: 1rem;
}

.page-about__timeline {
  position: relative;
  margin-top: 2rem;
}

.page-about__milestone {
  position: relative;
  padding-left: 2rem;
  padding-bottom: 2.5rem;
  border-left: 2px solid var(--x-card);
}

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

.page-about__milestone::before {
  content: '';
  position: absolute;
  left: -7px;
  top: 0.4rem;
  width: 12px;
  height: 12px;
  background: var(--x-bg-dark);
  border: 2px solid var(--x-neon-green);
  transform: rotate(45deg);
  transition: background-color 0.2s, border-color 0.2s;
}

.page-about__milestone:hover::before {
  background: var(--x-orange);
  border-color: var(--x-orange);
}

.page-about__milestone-index {
  display: inline-block;
  margin-bottom: 0.5rem;
  padding: 0.25rem 0.6rem;
  background: rgba(100, 255, 218, 0.08);
  border: 1px solid rgba(100, 255, 218, 0.28);
  color: var(--x-neon-green);
  font-family: var(--x-font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.04em;
}

.page-about__milestone-status {
  display: inline-block;
  margin-left: 0.5rem;
  color: rgba(226, 232, 240, 0.65);
  font-size: 0.75rem;
  font-family: var(--x-font-mono);
}

.page-about__milestone-card h3 {
  margin: 0.75rem 0 0.5rem;
  font-size: 1.25rem;
  color: var(--x-text-light);
}

.page-about__milestone-card ul {
  margin: 0.75rem 0 0;
  padding-left: 1.25rem;
  color: rgba(226, 232, 240, 0.72);
  line-height: 1.7;
}

.page-about__chapter-img {
  margin: 1.5rem 0;
}

.page-about__pipeline {
  display: grid;
  grid-template-columns: 1fr;
  gap: 0;
  margin: 1.5rem 0 2rem;
}

.page-about__pipeline-step {
  padding: 1.25rem;
  background: rgba(30, 41, 59, 0.5);
  border: 1px solid var(--x-card);
  border-radius: 10px;
}

.page-about__pipeline-step h3 {
  margin: 0.5rem 0 0.375rem;
  font-size: 1.0625rem;
  color: var(--x-text-light);
}

.page-about__pipeline-step p {
  margin: 0;
  font-size: 0.875rem;
}

.page-about__pipeline-arrow {
  position: relative;
  height: 2.5rem;
  color: var(--x-orange);
}

.page-about__pipeline-arrow::before {
  content: '';
  position: absolute;
  left: 50%;
  top: 0;
  width: 2px;
  height: 100%;
  background: var(--x-line-grid);
  transform: translateX(-50%);
}

.page-about__pipeline-arrow::after {
  content: '↓';
  position: absolute;
  left: 50%;
  top: 50%;
  transform: translate(-50%, -50%);
  font-size: 1.375rem;
  font-weight: 700;
  color: var(--x-orange);
  line-height: 1;
}

.page-about__tech-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 0.75rem;
  margin: 1.5rem 0;
}

.page-about__tech-item {
  padding: 1.25rem 1rem;
  border: 1px solid var(--x-card);
  background: rgba(17, 34, 64, 0.45);
  border-radius: 10px;
}

.page-about__tech-item strong {
  display: block;
  margin-bottom: 0.25rem;
  font-family: var(--x-font-mono);
  font-size: 1.5rem;
  color: var(--x-neon-green);
}

.page-about__tech-item span {
  font-size: 0.8125rem;
  color: rgba(226, 232, 240, 0.7);
}

.page-about__team-media {
  margin: 1.5rem 0;
}

.page-about__team-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 0.875rem;
  margin: 1.5rem 0;
}

.page-about__team-card {
  padding: 1.25rem;
  border: 1px solid var(--x-card);
  border-radius: 10px;
  background: rgba(17, 34, 64, 0.5);
}

.page-about__team-card h3 {
  margin: 0.5rem 0 0.375rem;
  font-size: 1.125rem;
  color: var(--x-text-light);
}

.page-about__team-card p {
  margin: 0;
  font-size: 0.9375rem;
}

.page-about__more-panel {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 1.5rem;
  padding: 2rem 1.5rem;
  border: 1px solid var(--x-card);
  border-radius: var(--x-radius);
  background:
    linear-gradient(135deg, rgba(100, 255, 218, 0.08), transparent 45%),
    var(--x-blue);
}

.page-about__more-panel h2 {
  margin: 0.5rem 0 0.5rem;
  font-size: 1.5rem;
  color: var(--x-text-light);
}

.page-about__more-panel p {
  margin: 0;
  color: rgba(226, 232, 240, 0.78);
}

.page-about__more-links {
  display: flex;
  flex-wrap: wrap;
  gap: 0.875rem;
}

@media (min-width: 900px) {
  .page-about__hero {
    padding: 4rem 0 3rem;
  }

  .page-about__hero-grid {
    grid-template-columns: 1.05fr 0.95fr;
    gap: 4rem;
  }

  .page-about__hero-copy h1 {
    font-size: 3rem;
  }

  .page-about__stat-grid {
    grid-template-columns: repeat(4, 1fr);
    padding: 2rem 0;
  }

  .page-about .hb-stat__value {
    font-size: 2.25rem;
  }

  .page-about__layout-grid {
    grid-template-columns: 280px 1fr;
    gap: 3rem;
    align-items: start;
  }

  .page-about__toc-inner {
    position: sticky;
    top: 7rem;
  }

  .page-about__chapter {
    padding: 2.5rem 2.75rem 3rem;
    margin-bottom: 2.5rem;
  }

  .page-about__chapter > h2 {
    font-size: 2rem;
  }

  .page-about__origin-grid {
    grid-template-columns: 1.35fr 0.65fr;
    gap: 2rem;
  }

  .page-about__pipeline {
    grid-template-columns: 1fr 1.75rem 1fr 1.75rem 1fr 1.75rem 1fr;
    align-items: center;
  }

  .page-about__pipeline-arrow {
    height: auto;
  }

  .page-about__pipeline-arrow::before {
    left: 0;
    top: 50%;
    width: 100%;
    height: 2px;
    transform: translateY(-50%);
  }

  .page-about__pipeline-arrow::after {
    content: '→';
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
  }

  .page-about__tech-grid {
    grid-template-columns: repeat(4, 1fr);
  }

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

  .page-about__more-panel {
    flex-direction: row;
    justify-content: space-between;
    align-items: center;
    padding: 2.5rem 3rem;
  }
}

@media (min-width: 1200px) {
  .page-about__hero-copy h1 {
    font-size: 3.375rem;
  }

  .page-about__chapter {
    padding-left: 3rem;
    padding-right: 3rem;
  }
}