body {
    margin: 0;
    padding: 0;
    overflow: hidden;
    background-color: #d6eaff;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    touch-action: none;
    user-select: none;
    transition: background-color 1s;
}

#game-container {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 1;
}

#ui-layer {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 10;
    pointer-events: none;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
}

#header {
    display: flex;
    justify-content: space-between;
    padding: 20px 30px;
    pointer-events: none;
}

#score-board {
    font-size: 48px;
    font-weight: bold;
    color: #333;
    text-shadow: 2px 2px 0px rgba(255,255,255,0.5);
}

#level-board {
    font-size: 24px;
    font-weight: bold;
    color: #555;
    background: rgba(255,255,255,0.6);
    padding: 10px 20px;
    border-radius: 20px;
    height: fit-content;
    align-self: center;
}

#game-over-screen {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
    display: none;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    pointer-events: auto;
    backdrop-filter: blur(8px);
    z-index: 20;
}

h1 {
    color: white;
    font-size: 40px;
    margin-bottom: 10px;
    text-shadow: 0 2px 5px rgba(0,0,0,0.3);
}

p {
    color: #eee;
    font-size: 20px;
    margin-bottom: 30px;
}

button {
    padding: 15px 40px;
    font-size: 24px;
    background: white;
    color: #333;
    border: none;
    border-radius: 50px;
    cursor: pointer;
    box-shadow: 0 5px 15px rgba(0,0,0,0.2);
    transition: transform 0.1s, background 0.2s;
    font-weight: bold;
}

button:active {
    transform: scale(0.95);
}
    
button:hover {
    background: #f0f0f0;
}

#tutorial {
    position: absolute;
    bottom: 100px;
    width: 100%;
    text-align: center;
    color: rgba(50, 50, 50, 0.8);
    font-size: 18px;
    font-weight: bold;
    animation: pulse 2s infinite;
    pointer-events: none;
}
    
#audio-tip {
    position: absolute;
    bottom: 10px;
    right: 10px;
    font-size: 12px;
    color: rgba(0,0,0,0.3);
}

@keyframes pulse {
    0% { opacity: 0.4; }
    50% { opacity: 1; }
    100% { opacity: 0.4; }
}