* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

body {
    background-color: #1a1a1a;
    color: #ffffff;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    overflow: hidden;
}

#game-container {
    position: relative;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.5);
    border-radius: 8px;
    overflow: hidden;
}

canvas {
    background-color: #111;
    display: block;
}

#ui-layer {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    padding: 20px;
    pointer-events: none;
}

#score-board {
    font-size: 24px;
    font-weight: bold;
    text-shadow: 2px 2px 4px rgba(0,0,0,0.8);
    pointer-events: auto;
}

#start-btn {
    align-self: center;
    margin-bottom: 40px;
    padding: 12px 28px;
    font-size: 18px;
    font-weight: bold;
    color: #fff;
    background-color: #ff4757;
    border: none;
    border-radius: 25px;
    cursor: pointer;
    box-shadow: 0 4px 15px rgba(255, 71, 87, 0.4);
    transition: transform 0.2s, background-color 0.2s;
    pointer-events: auto;
}

#start-btn:hover {
    background-color: #ff6b81;
    transform: scale(1.05);
}

#start-btn:active {
    transform: scale(0.95);
}