body {
  margin: 0;
  min-height: 100vh;
  font-family: Arial, Helvetica, sans-serif;
  color: #073b4c;
  background: linear-gradient(180deg, #49b6ff 0%, #087ea4 40%, #045b7a 100%);
}

* {
  box-sizing: border-box;
}

.app {
  min-height: 100vh;
  display: grid;
  place-items: center;
  padding: 20px;
}

.game-card {
  width: min(900px, 100%);
  background: rgba(255, 255, 255, 0.9);
  border-radius: 20px;
  padding: 20px;
  box-shadow: 0 12px 28px rgba(0, 0, 0, 0.2);
}

h1 {
  margin: 0;
  text-align: center;
}

.subtitle {
  text-align: center;
  margin: 8px 0 18px;
}

.hud {
  display: flex;
  justify-content: center;
  gap: 24px;
  font-weight: bold;
}

#startButton {
  display: block;
  margin: 8px auto 10px;
  border: 0;
  border-radius: 999px;
  background: #00c2ff;
  color: #003b4e;
  font-weight: bold;
  padding: 10px 22px;
  cursor: pointer;
  transition: transform 0.15s ease, box-shadow 0.15s ease;
}

#startButton:hover {
  transform: translateY(-1px);
  box-shadow: 0 6px 14px rgba(0, 135, 180, 0.3);
}

.message {
  text-align: center;
  min-height: 24px;
  margin: 0 0 12px;
}

.game-area {
  position: relative;
  height: 58vh;
  min-height: 320px;
  max-height: 560px;
  border-radius: 16px;
  overflow: hidden;
  background:
    radial-gradient(circle at 20% 20%, rgba(255, 255, 255, 0.25), transparent 34%),
    radial-gradient(circle at 80% 35%, rgba(255, 255, 255, 0.2), transparent 35%),
    linear-gradient(180deg, #8fe8ff 0%, #2da6d1 55%, #0a709b 100%);
}

.fish {
  position: absolute;
  border: 0;
  background: transparent;
  font-size: clamp(26px, 4vw, 38px);
  cursor: pointer;
  user-select: none;
  line-height: 1;
  transition: transform 0.9s ease;
  animation: bob 1s ease-in-out infinite;
}

@keyframes bob {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-4px); }
}

@media (max-width: 640px) {
  .hud {
    gap: 14px;
    font-size: 0.95rem;
  }

  .game-area {
    min-height: 260px;
    height: 52vh;
  }
}