body {
    margin: 0;
    padding: 0;
    overflow: hidden;
    background-color: #2980b9;
    color: #fff;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    touch-action: none;
    user-select: none;
}

#game-container {
    position: relative;
    width: 100vw;
    height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    background: linear-gradient(to bottom, #1abc9c 0%, #3498db 50%, #2ecc71 100%);
}

#game-canvas {
    max-width: 100%;
    max-height: 100%;
}

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

#top-bar {
    position: absolute;
    top: 20px;
    left: 20px;
    right: 20px;
    display: flex;
    justify-content: space-between;
}

#score-display {
    font-size: 3rem;
    font-weight: bold;
    color: #fff;
    text-shadow: 0 4px 0 #16a085, 0 8px 10px rgba(0,0,0,0.5);
    margin: 0;
}

#coin-display {
    font-size: 2.5rem;
    font-weight: bold;
    color: #f1c40f;
    text-shadow: 0 4px 0 #d35400, 0 8px 10px rgba(0,0,0,0.5);
    margin: 0;
}

#start-screen, #game-over-screen {
    pointer-events: auto;
    background: rgba(255, 255, 255, 0.95);
    padding: 40px 60px;
    border-radius: 20px;
    box-shadow: 0 15px 35px rgba(0,0,0,0.4), inset 0 2px 10px rgba(255,255,255,1);
    text-align: center;
    border: 5px solid #e74c3c;
    color: #333;
}

h2 {
    font-size: 3.5rem;
    margin-top: 0;
    margin-bottom: 20px;
    color: #c0392b;
    text-shadow: 0 2px 5px rgba(0,0,0,0.2);
}

p {
    font-size: 1.2rem;
    margin-bottom: 30px;
    font-weight: bold;
    color: #555;
}

/* Button */
.btn {
    pointer-events: auto;
    font-size: 1.5rem;
    padding: 15px 40px;
    border: none;
    border-radius: 12px;
    background: linear-gradient(135deg, #e74c3c 0%, #c0392b 100%);
    color: white;
    font-weight: bold;
    cursor: pointer;
    box-shadow: 0 6px 0 #922b21, 0 10px 15px rgba(0,0,0,0.3);
    transition: transform 0.1s, box-shadow 0.1s;
}

.btn:active {
    transform: translateY(6px);
    box-shadow: 0 0px 0 #922b21, 0 4px 5px rgba(0,0,0,0.3);
}