.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  position: relative;
  overflow: hidden;
}

.hero-wave {
  position: absolute;
  inset: 0;
  opacity: 0.1;
  pointer-events: none;
  animation: drift-wave 20s linear infinite;
  z-index: 0;
}

.hero-wave svg {
  width: 120%;
  min-width: 960px;
  margin-left: -10%;
  margin-top: -6%;
}

.hero-index {
  background: var(--color-bg-deep);
}

.hero-research {
  background: var(--color-bg-surface);
}

.hero-artefacts {
  background: var(--color-bg-deep);
  min-height: 68vh;
}

.hero-artefacts::before {
  content: '';
  position: absolute;
  inset: 0;
  background-image: radial-gradient(circle at 1px 1px, rgba(232, 232, 240, 0.16) 1px, transparent 0);
  background-size: 26px 26px;
  opacity: 0.035;
}

.hero-artefacts::after {
  content: '';
  position: absolute;
  inset: 0;
  background:
    radial-gradient(ellipse 60% 55% at 15% 60%, rgba(0, 212, 212, 0.07) 0%, transparent 70%),
    radial-gradient(ellipse 50% 45% at 85% 40%, rgba(123, 47, 255, 0.07) 0%, transparent 70%);
  pointer-events: none;
}

.hero-research::before {
  content: '';
  position: absolute;
  inset: 0;
  background-image: radial-gradient(circle at 1px 1px, rgba(232, 232, 240, 0.16) 1px, transparent 0);
  background-size: 26px 26px;
  opacity: 0.04;
}

.hero-content {
  position: relative;
  z-index: 1;
  display: grid;
  gap: var(--space-4);
  align-items: center;
}

.hero-copy {
  display: grid;
  gap: var(--space-2);
  max-width: 740px;
}

.hero-support {
  font-size: 0.95rem;
}

.hero-abstract {
  display: none;
}

.hero-diagram {
  width: 100%;
  height: auto;
  min-height: 300px;
  overflow: visible;
}

.chaos-lines {
  stroke: #00d4d4;
  stroke-width: 1.4;
  opacity: 0.45;
  fill: none;
  transition: opacity 0.5s ease;
}

.nd {
  fill: #00d4d4;
  opacity: 0.88;
  stroke: rgba(0, 212, 212, 0.5);
  stroke-width: 2;
  filter: drop-shadow(0 0 5px #00d4d4);
  transform-box: fill-box;
  transform-origin: center;
}

.grid-lines {
  stroke: #7b2fff;
  stroke-width: 1.4;
  opacity: 0.45;
  fill: none;
  transition: opacity 0.4s ease;
}

.gn {
  fill: #7b2fff;
  opacity: 0.82;
  stroke: rgba(123, 47, 255, 0.6);
  stroke-width: 2;
  filter: drop-shadow(0 0 5px #7b2fff);
  transform-box: fill-box;
  transform-origin: center;
}

.diagram-label {
  font-family: var(--font-body);
  font-size: 12px;
  letter-spacing: 0.14em;
  font-weight: 600;
  opacity: 0.6;
  transition: opacity 0.4s ease;
}

.label-chaos { fill: #00d4d4; }
.label-grid  { fill: #7b2fff; }

.hero-abstract:hover .diagram-label { opacity: 1; }
.hero-abstract:hover .chaos-lines   { opacity: 0.72; }
.hero-abstract:hover .grid-lines    { opacity: 0.65; }
.hero-abstract:hover .nd            { filter: drop-shadow(0 0 9px #00d4d4); }
.hero-abstract:hover .gn            { opacity: 0.98; filter: drop-shadow(0 0 9px #7b2fff); }

.comparison-panel {
  border-top: 3px solid var(--color-accent-cyan);
}

.comparison-panel.purple {
  border-top-color: var(--color-accent-purple);
}

.center-block {
  max-width: 720px;
  margin-inline: auto;
  display: grid;
  gap: var(--space-2);
}

.feature-grid {
  display: grid;
  gap: var(--space-3);
}

.feature-card.transformative {
  border-color: rgba(0, 212, 212, 0.36);
  border-radius: 16px;
}

.feature-card.improvement {
  border-color: rgba(123, 47, 255, 0.4);
  border-radius: 10px;
}

.artifact-card,
.framework-card {
  display: grid;
  gap: var(--space-2);
}

.artifact-card .feature-card,
.framework-card .feature-card {
  padding: var(--space-2);
}

@keyframes drift-wave {
  0% { transform: translateX(0) translateY(0); }
  50% { transform: translateX(-2%) translateY(1.5%); }
  100% { transform: translateX(0) translateY(0); }
}

@media (min-width: 768px) {
  .hero-content {
    grid-template-columns: 1.1fr 0.9fr;
  }

  .hero-copy {
    gap: var(--space-3);
  }

  .hero-abstract {
    display: flex;
    align-items: center;
  }

  .feature-grid.two {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .feature-grid.four {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (min-width: 1024px) {
  .feature-grid.four {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}