Modern CSS Gradient Effects

<div class="d-flex flex-wrap align-items-center justify-content-center gap-3 p-3 h-100" style="min-height:200px">
  <div class="fx-animated-rainbow rounded-4 p-4 text-center w-100" style="max-width:18rem;text-shadow:0 1px 3px rgba(0,0,0,.3)">
    <h3 class="h5 fw-bold mb-1">Get answers, get better</h3>
    <p class="small mb-0">Every colour, always moving.</p>
  </div>
  <button type="button" class="btn rounded-pill border-0 fx-animated-rainbow">Celebrate</button>
</div>

/* CSS (already in assets/css/effects.css) */
.fx-animated-rainbow {
  color: #fff;
  background: linear-gradient(90deg, #ff3d7f, #ff9f1c, #ffd23f, #3bce73, #2ec4ff, #7b5cff, #ff3d7f);
  background-size: 300% 100%;
  animation: fx-animated-rainbow-flow 8s linear infinite;
}
@keyframes fx-animated-rainbow-flow { to { background-position: -150% 0; } }
@media (prefers-reduced-motion: reduce) {
  .fx-animated-rainbow, .fx-animated-rainbow::before, .fx-animated-rainbow::after, .fx-animated-rainbow *, .fx-animated-rainbow *::before, .fx-animated-rainbow *::after { animation: none !important; transition: none !important; }
}

<div class="d-flex flex-wrap align-items-center justify-content-center gap-3 p-3 h-100" style="min-height:200px">
  <div class="card fx-animated-border" style="width:13rem">
    <div class="card-body text-center">
      <div class="fs-2 text-primary">
        <i class="bi bi-trophy-fill" aria-hidden="true"></i>
      </div>
      <h3 class="h6 mb-1">Business plan</h3>
      <p class="small text-body-secondary mb-0">$32.61 / month</p>
    </div>
  </div>
</div>

/* CSS (already in assets/css/effects.css) */
@property --fx-animated-border-angle { syntax: "<angle>"; inherits: false; initial-value: 0deg; }
.fx-animated-border {
  border: 3px solid transparent;
  background:
    linear-gradient(var(--wt-surface, #fff), var(--wt-surface, #fff)) padding-box,
    conic-gradient(from var(--fx-animated-border-angle), var(--wt-primary), var(--wt-accent), var(--wt-secondary), var(--wt-primary)) border-box;
  animation: fx-animated-border-turn 4s linear infinite;
}
@keyframes fx-animated-border-turn { to { --fx-animated-border-angle: 360deg; } }
@media (prefers-reduced-motion: reduce) {
  .fx-animated-border, .fx-animated-border::before, .fx-animated-border::after, .fx-animated-border *, .fx-animated-border *::before, .fx-animated-border *::after { animation: none !important; transition: none !important; }
}

<div class="d-flex flex-wrap align-items-center justify-content-center gap-3 p-3 h-100" style="min-height:200px">
  <div class="fx-iridescent rounded-4 p-4 shadow-sm" style="width:15rem">
    <div class="d-flex justify-content-between align-items-start mb-4">
      <span class="fw-bold">Solao Base</span><i class="bi bi-gem" aria-hidden="true"></i>
    </div>
    <div class="font-monospace small mb-1">
      **** **** **** 1113
    </div>
    <div class="small">
      Tariq Alvarez
    </div>
  </div>
</div>

/* CSS (already in assets/css/effects.css) */
.fx-iridescent {
  position: relative; overflow: hidden; color: #1d1d2b;
  background: linear-gradient(120deg, #f6d5f7, #fbe9d7, #d5f2ef, #d7e2fb, #e9d5fb, #f6d5f7);
  background-size: 300% 300%; background-position: 0% 50%;
  transition: background-position 1.2s ease;
}
.fx-iridescent::after {
  content: ""; position: absolute; inset: 0; pointer-events: none; mix-blend-mode: overlay;
  background: linear-gradient(105deg, transparent 35%, rgba(255, 255, 255, .7) 50%, transparent 65%);
  background-size: 250% 100%; background-position: 100% 0; transition: background-position 1.2s ease;
}
.fx-iridescent:hover, .fx-iridescent:focus-within { background-position: 100% 50%; }
.fx-iridescent:hover::after, .fx-iridescent:focus-within::after { background-position: 0 0; }
@media (prefers-reduced-motion: reduce) {
  .fx-iridescent, .fx-iridescent::before, .fx-iridescent::after, .fx-iridescent *, .fx-iridescent *::before, .fx-iridescent *::after { animation: none !important; transition: none !important; }
}