Advanced Animated Backgrounds

<section class="fx-bg-particles bg-dark text-white rounded-4 p-4 text-center d-flex flex-column justify-content-center" style="min-height:210px">
  <p class="small text-uppercase fw-semibold mb-1 text-white-50">Particles</p>
  <h3 class="h4 fw-bold mb-2">The online school for busy people</h3>
  <p class="small mb-3 text-white-50">Content stays readable on top of the moving background.</p>
  <div>
    <a href="#" class="btn btn-primary btn-sm">Get started</a>
  </div>
</section>

/* CSS (already in assets/css/effects.css) */
.fx-bg-particles { position: relative; isolation: isolate; overflow: hidden; }
.fx-bg-particles::before, .fx-bg-particles::after { content: ""; position: absolute; pointer-events: none; z-index: -1; }
.fx-bg-particles::before, .fx-bg-particles::after { inset: 0; }
.fx-bg-particles::before {
  background-image:
    radial-gradient(circle at 10% 20%, rgba(var(--wt-primary-rgb), .65) 0 2px, transparent 3px),
    radial-gradient(circle at 35% 70%, rgba(var(--wt-accent-rgb), .6) 0 1.5px, transparent 2.5px),
    radial-gradient(circle at 60% 35%, rgba(var(--wt-secondary-rgb), .55) 0 2px, transparent 3px),
    radial-gradient(circle at 85% 80%, rgba(var(--wt-primary-rgb), .5) 0 1.5px, transparent 2.5px);
  background-size: 180px 180px;
  animation: fx-bg-particles-near 14s linear infinite;
}
.fx-bg-particles::after {
  opacity: .7;
  background-image:
    radial-gradient(circle at 20% 55%, rgba(var(--wt-accent-rgb), .55) 0 3px, transparent 4px),
    radial-gradient(circle at 70% 15%, rgba(var(--wt-primary-rgb), .45) 0 3.5px, transparent 4.5px),
    radial-gradient(circle at 50% 90%, rgba(var(--wt-secondary-rgb), .4) 0 2.5px, transparent 3.5px);
  background-size: 300px 300px;
  animation: fx-bg-particles-far 30s linear infinite;
}
@keyframes fx-bg-particles-near { to { background-position: 0 -180px; } }
@keyframes fx-bg-particles-far { to { background-position: 0 -300px; } }
@media (prefers-reduced-motion: reduce) {
  .fx-bg-particles, .fx-bg-particles::before, .fx-bg-particles::after, .fx-bg-particles *, .fx-bg-particles *::before, .fx-bg-particles *::after { animation: none !important; transition: none !important; }
}

<section class="fx-bg-shapes bg-body border rounded-4 p-4 text-center d-flex flex-column justify-content-center" style="min-height:210px">
  <p class="small text-uppercase fw-semibold mb-1 text-body-secondary">Floating shapes</p>
  <h3 class="h4 fw-bold mb-2">Learn by doing, not just watching</h3>
  <p class="small mb-3 text-body-secondary">Content stays readable on top of the moving background.</p>
  <div>
    <a href="#" class="btn btn-primary btn-sm">Get started</a>
  </div>
</section>

/* CSS (already in assets/css/effects.css) */
.fx-bg-shapes { position: relative; isolation: isolate; overflow: hidden; }
.fx-bg-shapes::before, .fx-bg-shapes::after { content: ""; position: absolute; pointer-events: none; z-index: -1; }
.fx-bg-shapes::before, .fx-bg-shapes::after { inset: -10%; background-repeat: no-repeat; }
.fx-bg-shapes::before {
  background-image:
    radial-gradient(circle, transparent 0 38%, rgba(var(--wt-primary-rgb), .35) 40% 50%, transparent 52%),
    radial-gradient(circle, rgba(var(--wt-accent-rgb), .35) 0 48%, transparent 50%),
    conic-gradient(from 150deg at 50% 0, rgba(var(--wt-secondary-rgb), .3) 0 60deg, transparent 0);
  background-size: 90px 90px, 34px 34px, 70px 60px;
  background-position: 12% 22%, 82% 18%, 70% 82%;
  animation: fx-bg-shapes-float 12s ease-in-out infinite alternate;
}
.fx-bg-shapes::after {
  background-image:
    linear-gradient(rgba(var(--wt-secondary-rgb), .22), rgba(var(--wt-secondary-rgb), .22)),
    radial-gradient(circle, transparent 0 40%, rgba(var(--wt-accent-rgb), .3) 42% 52%, transparent 54%),
    radial-gradient(circle, rgba(var(--wt-primary-rgb), .3) 0 48%, transparent 50%);
  background-size: 38px 38px, 60px 60px, 22px 22px;
  background-position: 88% 62%, 22% 80%, 45% 12%;
  animation: fx-bg-shapes-turn 18s ease-in-out infinite alternate;
}
@keyframes fx-bg-shapes-float { to { transform: translate(3%, -5%) rotate(6deg); } }
@keyframes fx-bg-shapes-turn { to { transform: translate(-4%, 4%) rotate(-8deg); } }
@media (prefers-reduced-motion: reduce) {
  .fx-bg-shapes, .fx-bg-shapes::before, .fx-bg-shapes::after, .fx-bg-shapes *, .fx-bg-shapes *::before, .fx-bg-shapes *::after { animation: none !important; transition: none !important; }
}