body {
    margin: 0;
    padding: 0;
    background-color: #121212;
    color: #FFFFFF;
    font-family: 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
    height: 100vh;
    width: 100vw;
    display: flex;
    justify-content: center;
    align-items: center;
    overflow: hidden;
}

#app {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    width: 100%;
    text-align: center;
}

h1 {
    font-size: 1.5rem;
    letter-spacing: 2px;
    opacity: 0.6;
    position: absolute;
    top: 40px; 
    margin: 0;
}

#play-random, #login-btn {
    background-color: #1DB954;
    color: white;
    border: none;
    border-radius: 500px;
    padding: 20px 60px;
    font-size: 1.5rem;
    font-weight: bold;
    cursor: pointer;
    transition: transform 0.2s, background-color 0.2s;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.5);
    text-transform: uppercase;
}

#reveal-song, #next-song {
    background-color: #8B5CF6;
    color: white;
    border: none;
    border-radius: 500px;
    padding: 20px 60px;
    font-size: 1.5rem;
    font-weight: bold;
    cursor: pointer;
    transition: transform 0.2s, background-color 0.2s;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.5);
    text-transform: uppercase;
}

#play-random.playing {
    background-color: #e91e63; /* Spotify-style Red/Pink */
}

#play-random:hover, #login-btn:hover {
    background-color: #1ed760;
    transform: scale(1.05);
}

#reveal-song:hover, #next-song:hover {
    background-color: #a78bfa;
    transform: scale(1.05);
}

#play-random.playing:hover {
    background-color: #ff4081; /* A lighter, bright pink/red */
    transform: scale(1.05);
}

#play-random:active, #login-btn:active, #reveal-song:active, #next-song:active {
    transform: scale(0.95);
}

#reveal-song {
    margin: 30px auto 0;
}

#next-song {
    margin: 20px auto 0;
}

#game-ui p {
    margin-bottom: 20px;
    color: #b3b3b3;
    font-size: 0.9rem;
}

#audio-visualizer {
    display: flex;
    gap: 10px;
    justify-content: center;
    align-items: flex-end;
    height: 80px;
    margin: 0 auto 15px;
}

.bar {
    width: 8px;
    background: linear-gradient(to top, #1DB954, #1ed760);
    border-radius: 4px;
    height: 8px;
    transition: none;
}

#audio-visualizer.playing .bar {
    animation: dance 0.6s ease-in-out infinite;
}

#audio-visualizer.playing .bar:nth-child(1) {
    animation-delay: 0s;
    animation-duration: 0.8s;
}

#audio-visualizer.playing .bar:nth-child(2) {
    animation-delay: 0.1s;
    animation-duration: 0.6s;
}

#audio-visualizer.playing .bar:nth-child(3) {
    animation-delay: 0.2s;
    animation-duration: 0.7s;
}

#audio-visualizer.playing .bar:nth-child(4) {
    animation-delay: 0.1s;
    animation-duration: 0.6s;
}

#audio-visualizer.playing .bar:nth-child(5) {
    animation-delay: 0s;
    animation-duration: 0.8s;
}

@keyframes dance {
    0%, 100% {
        height: 8px;
    }
    50% {
        height: 50px;
    }
}