body {
    margin: 0;
    overflow: hidden;
    background-color: #001a33; /* Dark blue fallback */
}

.background-container {
    position: fixed;
    top: -50px;
    left: -50px;
    width: calc(100% + 100px);
    height: calc(100% + 100px);
    z-index: -3;
    overflow: hidden;
}

.wavy-background {
    width: 100%;
    height: 100%;
    background-image: url('ocean_background.jpg');
    background-size: cover;
    background-position: center;
    filter: url(#ocean-wave);
    position: absolute;
    top: 0;
    left: 0;
    z-index: 1;
}

.extra-layer {
    width: 100%;
    height: 100%;
    background-size: cover;
    background-position: center;
    filter: url(#ocean-wave-subtle);
    position: absolute;
    top: 0;
    left: 0;
    z-index: 2;
    display: none; /* Hidden by default */
}

.wavy-layer-2 {
    position: fixed;
    top: -50px;
    left: -50px;
    width: calc(100% + 100px);
    height: calc(100% + 100px);
    background-image: url('ocean_plants.png');
    background-size: cover;
    background-position: center;
    filter: url(#ocean-wave-subtle);
    z-index: 0;
    pointer-events: none; /* Ensure it doesn't block clicks */
}

#oceanCanvas {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: -2; /* Behind everything but the background */
}

#submarine {
    position: absolute;
    width: 300px;
    height: auto;
    left: -200px; /* Start off-screen */
    top: 50%;
    transform: translateY(-50%);
    z-index: 1; /* Default: above plants (z-index 0) */
    filter: url(#submarine-wave);
}

.fish {
    position: absolute;
    width: 100px;
    height: auto;
    pointer-events: none;
    z-index: 1;
    filter: url(#submarine-wave); /* Reuse the subtle wave filter */
}

.top-right-container {
    position: fixed;
    top: 20px;
    right: 20px;
    z-index: 100;
    display: flex;
    flex-direction: column;
    align-items: flex-end;
    gap: 5px;
}

.top-right-btn {
    padding: 10px 15px;
    background-color: rgba(0, 26, 51, 0.7);
    color: white;
    border: 1px solid white;
    border-radius: 5px;
    cursor: pointer;
    font-family: Arial, sans-serif;
    transition: background-color 0.3s;
}

.music-credits {
    color: white;
    font-family: Arial, sans-serif;
    font-size: 10px;
    background-color: rgba(0, 26, 51, 0.5);
    padding: 2px 8px;
    border-radius: 3px;
}

.music-credits a {
    color: white;
    text-decoration: underline;
}


.music-credits a:hover {
    color: darkgray;
    text-decoration: underline;
}

.top-right-btn:hover {
    background-color: rgba(0, 51, 102, 0.9);
}

.top-left-info {
    position: fixed;
    top: 20px;
    left: 20px;
    z-index: 100;
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 10px 15px;
    color: white;
    font-family: Arial, sans-serif;
}

.top-center-info {
    position: fixed;
    top: 20px;
    left: 50%;
    text-align: center;
    transform: translateX(-50%);
    z-index: 100;
    padding: 10px 20px;
    background-color: rgba(0, 26, 51, 0.7);
    color: white;
    border: 1px solid white;
    border-radius: 5px;
    font-family: Arial, sans-serif;
    pointer-events: none;
}