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

body {
    background: linear-gradient(180deg, #1a1a2e 0%, #16213e 100%);
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    overflow: hidden;
    touch-action: none;
    -webkit-touch-callout: none;
    -webkit-user-select: none;
    user-select: none;
}

#game-container {
    position: relative;
    border-radius: 8px;
    overflow: hidden;
    box-shadow: 0 0 40px rgba(255, 140, 0, 0.3);
}

#gameCanvas {
    display: block;
    cursor: pointer;
    max-width: 100vw;
    max-height: 100vh;
}

#back-btn {
    position: absolute;
    top: 10px;
    left: 10px;
    color: rgba(255, 255, 255, 0.7);
    text-decoration: none;
    font-size: 14px;
    font-weight: bold;
    padding: 5px 12px;
    background: rgba(0, 0, 0, 0.4);
    border-radius: 15px;
    transition: background 0.2s, color 0.2s;
    z-index: 10;
}

#back-btn:hover {
    background: rgba(0, 0, 0, 0.7);
    color: #ff8c00;
}