Advanced Animated Backgrounds

<section class="fx-bg-gradient-flow 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">Gradient flow</p>
  <h3 class="h4 fw-bold mb-2">Simple dishes, honest ingredients</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-gradient-flow { position: relative; isolation: isolate; overflow: hidden; }
.fx-bg-gradient-flow::before, .fx-bg-gradient-flow::after { content: ""; position: absolute; pointer-events: none; z-index: -1; }
.fx-bg-gradient-flow::before {
  inset: 0;
  background: linear-gradient(120deg, rgba(var(--wt-primary-rgb), .30), rgba(var(--wt-secondary-rgb), .22), rgba(var(--wt-accent-rgb), .28), rgba(var(--wt-primary-rgb), .30));
  background-size: 300% 300%;
  animation: fx-bg-gradient-flow-flow 16s ease infinite;
}
@keyframes fx-bg-gradient-flow-flow { 0%, 100% { background-position: 0% 50%; } 50% { background-position: 100% 50%; } }
@media (prefers-reduced-motion: reduce) {
  .fx-bg-gradient-flow, .fx-bg-gradient-flow::before, .fx-bg-gradient-flow::after, .fx-bg-gradient-flow *, .fx-bg-gradient-flow *::before, .fx-bg-gradient-flow *::after { animation: none !important; transition: none !important; }
}

<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">A table for every occasion</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-wave-blob 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">Wave and blob</p>
  <h3 class="h4 fw-bold mb-2">Fresh flavours, made every day</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-wave-blob { position: relative; isolation: isolate; overflow: hidden; }
.fx-bg-wave-blob::before, .fx-bg-wave-blob::after { content: ""; position: absolute; pointer-events: none; z-index: -1; }
.fx-bg-wave-blob::before {
  width: 55%; aspect-ratio: 1; top: -25%; left: -12%;
  background: radial-gradient(circle at 50% 50%, rgba(var(--wt-primary-rgb), .32), transparent 68%);
  border-radius: 42% 58% 63% 37% / 41% 44% 56% 59%;
  animation: fx-bg-wave-blob-blob 14s ease-in-out infinite alternate;
}
.fx-bg-wave-blob::after {
  left: 0; right: 0; bottom: 0; height: 60px;
  background:
    radial-gradient(84px 18px at 50% 100%, rgba(var(--wt-primary-rgb), .2) 99%, transparent 101%) 0 100% / 160px 30px repeat-x,
    radial-gradient(118px 24px at 50% 100%, rgba(var(--wt-accent-rgb), .18) 99%, transparent 101%) 0 100% / 220px 40px repeat-x,
    linear-gradient(rgba(var(--wt-primary-rgb), .14), rgba(var(--wt-primary-rgb), .14)) 0 100% / 100% 12px no-repeat;
  animation: fx-bg-wave-blob-wave 9s linear infinite;
}
@keyframes fx-bg-wave-blob-blob {
  0% { transform: translate(0, 0) rotate(0deg); border-radius: 42% 58% 63% 37% / 41% 44% 56% 59%; }
  50% { border-radius: 70% 30% 46% 54% / 30% 39% 61% 70%; }
  100% { transform: translate(110%, 35%) rotate(60deg); border-radius: 30% 70% 70% 30% / 53% 30% 70% 47%; }
}
@keyframes fx-bg-wave-blob-wave { to { background-position: 160px 100%, -220px 100%, 0 100%; } }
@media (prefers-reduced-motion: reduce) {
  .fx-bg-wave-blob, .fx-bg-wave-blob::before, .fx-bg-wave-blob::after, .fx-bg-wave-blob *, .fx-bg-wave-blob *::before, .fx-bg-wave-blob *::after { animation: none !important; transition: none !important; }
}