<div class="bga-02">
  <div class="bga-02__scene">
    <div class="bga-02__bubbles">
      <span class="bga-02__bubble"></span><span class="bga-02__bubble"></span><span class="bga-02__bubble"></span>
      <span class="bga-02__bubble"></span><span class="bga-02__bubble"></span><span class="bga-02__bubble"></span>
      <span class="bga-02__bubble"></span><span class="bga-02__bubble"></span><span class="bga-02__bubble"></span>
      <span class="bga-02__bubble"></span><span class="bga-02__bubble"></span><span class="bga-02__bubble"></span>
      <span class="bga-02__bubble"></span><span class="bga-02__bubble"></span><span class="bga-02__bubble"></span>
    </div>
  </div>
</div>

.bga-02, .bga-02 *, .bga-02 *::before, .bga-02 *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

.bga-02 {
  min-height: 460px;
  display: grid;
  place-items: stretch;
}

.bga-02__scene {
  width: 100%;
  min-height: 460px;
  position: relative;
  overflow: hidden;
  background: radial-gradient(circle at 50% 120%, #1b2a4a 0%, #0a0f1f 60%, #05060d 100%);
}

.bga-02__bubbles { position: absolute; inset: 0; }

.bga-02__bubble {
  position: absolute;
  bottom: -160px;
  border-radius: 50%;
  background: radial-gradient(circle at 30% 30%,
    rgba(255,255,255,0.9),
    rgba(120,200,255,0.35) 40%,
    rgba(80,140,255,0.05) 70%);
  box-shadow: 0 0 24px rgba(120,200,255,0.35),
              inset 0 0 12px rgba(255,255,255,0.4);
  opacity: 0;
  animation: bga-02-rise linear infinite;
}

@keyframes bga-02-rise {
  0%   { transform: translateY(0) translateX(0) scale(0.6); opacity: 0; }
  10%  { opacity: 0.9; }
  50%  { transform: translateY(-55vh) translateX(30px) scale(1); }
  90%  { opacity: 0.7; }
  100% { transform: translateY(-115vh) translateX(-20px) scale(1.2); opacity: 0; }
}

/* Individually tuned bubbles for an organic feel */
.bga-02__bubble:nth-child(1)  { left: 5%;  width: 28px; height: 28px; animation-duration: 14s; animation-delay: 0s; }
.bga-02__bubble:nth-child(2)  { left: 14%; width: 56px; height: 56px; animation-duration: 20s; animation-delay: 2s; }
.bga-02__bubble:nth-child(3)  { left: 22%; width: 18px; height: 18px; animation-duration: 11s; animation-delay: 4s; }
.bga-02__bubble:nth-child(4)  { left: 31%; width: 72px; height: 72px; animation-duration: 24s; animation-delay: 1s; }
.bga-02__bubble:nth-child(5)  { left: 40%; width: 34px; height: 34px; animation-duration: 16s; animation-delay: 6s; }
.bga-02__bubble:nth-child(6)  { left: 48%; width: 22px; height: 22px; animation-duration: 13s; animation-delay: 3s; }
.bga-02__bubble:nth-child(7)  { left: 56%; width: 60px; height: 60px; animation-duration: 22s; animation-delay: 5s; }
.bga-02__bubble:nth-child(8)  { left: 64%; width: 16px; height: 16px; animation-duration: 10s; animation-delay: 7s; }
.bga-02__bubble:nth-child(9)  { left: 72%; width: 44px; height: 44px; animation-duration: 18s; animation-delay: 0.5s; }
.bga-02__bubble:nth-child(10) { left: 80%; width: 80px; height: 80px; animation-duration: 26s; animation-delay: 8s; }
.bga-02__bubble:nth-child(11) { left: 88%; width: 26px; height: 26px; animation-duration: 15s; animation-delay: 4.5s; }
.bga-02__bubble:nth-child(12) { left: 94%; width: 50px; height: 50px; animation-duration: 21s; animation-delay: 2.5s; }
.bga-02__bubble:nth-child(13) { left: 10%; width: 40px; height: 40px; animation-duration: 19s; animation-delay: 9s; }
.bga-02__bubble:nth-child(14) { left: 36%; width: 14px; height: 14px; animation-duration: 9s;  animation-delay: 6.5s; }
.bga-02__bubble:nth-child(15) { left: 68%; width: 30px; height: 30px; animation-duration: 17s; animation-delay: 3.5s; }

@media (prefers-reduced-motion: reduce) {
  .bga-02__bubble {
    animation: none !important;
  }
}