/* Reset and base */
html,
body {
  margin: 0;
  padding: 0;
  height: 100%;
  width: 100%;
  overflow: hidden;
  font-family: sans-serif;
}

/* Aquarium background gradient */
.aquarium {
  position: absolute;
  inset: 0;
  /* You can choose either gradient, I kept the first one */
  background: linear-gradient(to bottom, #246d88 0%, #000000 100%);
  overflow: hidden;
  z-index: -3;
}

/* Caustics with SVG filter animation */
.caustics {
  position: absolute;
  inset: 0;
  mix-blend-mode: overlay;
  animation: causticMove 15s linear infinite;
  opacity: 0.08;
}
@keyframes causticMove {
  0% {
    transform: translateX(0);
  }
  100% {
    transform: translateX(-5%);
  }
}

/* Sea grass */
.sea-grass {
  position: absolute;
  bottom: 0;
  left: var(--x);
  width: 12px;
  height: 40vh;
  background: rgba(255, 255, 255, 0.05);
  border-radius: 50% 50% 0 0;
  animation: sway 6s ease-in-out infinite;
  animation-delay: var(--delay);
}
@keyframes sway {
  0%,
  100% {
    transform: rotate(0deg);
  }
  50% {
    transform: rotate(3deg);
  }
}

/* Coral silhouette */
.coral {
  position: absolute;
  bottom: 0;
  left: 5%;
  width: 20%;
  height: 40%;
  /* fill is handled by SVG path */
}

/* Particles (tiny specs for depth) */
.particles::before {
  content: "";
  position: absolute;
  inset: 0;
  background: radial-gradient(rgba(255, 255, 255, 0.04) 1px, transparent 1px)
    repeat;
  background-size: 3px 3px;
  animation: driftParticles 60s linear infinite;
  pointer-events: none;
}
@keyframes driftParticles {
  from {
    transform: translateY(0);
  }
  to {
    transform: translateY(-50px);
  }
}

/* Fish silhouettes */
.decor-fish {
  position: absolute;
  width: 80px;
  height: 35px;
  background: rgba(255, 255, 255, 0.08);
  border-radius: 50%;
  animation: drift 10s infinite;
}
.decor-fish::before {
  content: "";
  position: absolute;
  right: -10px;
  top: 50%;
  width: 20px;
  height: 12px;
  border-radius: 50%;
  background: inherit;
  transform: translateY(-50%);
}
.decor-fish.small {
  opacity: 0.15;
}
.decor-fish.medium {
  opacity: 0.25;
}
@keyframes drift {
  0%,
  100% {
    transform: translateX(0);
  }
  50% {
    transform: translateX(15px);
  }
}

/* Plants (alternative to sea grass if you want both) */
.plants {
  position: absolute;
  bottom: 0;
  width: 100%;
  height: 50%;
}
.plant {
  position: absolute;
  bottom: 0;
  left: var(--x);
  width: 30px;
  height: var(--h);
  background: linear-gradient(#1e6428, #0e5a3c);
  border-radius: 50% 50% 0 0;
  animation: sway 4s ease-in-out infinite;
  animation-delay: var(--delay);
}

/* Seabed rocks */
.seabed {
  position: absolute;
  bottom: 0;
  width: 100%;
  height: 15%;
}
.rock {
  position: absolute;
  bottom: 0;
  width: 150px;
  height: 60px;
  border-radius: 50%;
  background: #2a2219;
}

/* Bubbles */
.bubbles {
  position: absolute;
  inset: 0;
  pointer-events: none;
}
.bubble {
  position: absolute;
  bottom: -50px;
  left: var(--left);
  width: var(--size);
  height: var(--size);
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.2);
  backdrop-filter: blur(2px);
  animation: rise var(--dur) linear infinite;
  animation-delay: var(--delay);
}
@keyframes rise {
  0% {
    transform: translateY(0) scale(1);
    opacity: 0;
  }
  10% {
    opacity: 0.4;
  }
  100% {
    transform: translateY(-110vh) scale(0.5);
    opacity: 0;
  }
}

/* Whale on top */
#whale {
  position: absolute;
  inset: 0;
  z-index: 1;
}

/* Overlay text */
.overlay-text {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  font-size: 2em;
  font-family: cursive, sans-serif;
  text-align: center;
  color: white;
  text-shadow: 0 2px 4px rgba(0, 0, 0, 0.4);
  z-index: 2;
}
.decor-fish-svg {
  position: absolute;
  width: 100px;
  height: 50px;
  cursor: default;
  user-select: none;
  will-change: transform;
}