html, body {
    margin: 0;
    padding: 0;
    width: 100%;
    height: 100%;
    overflow: hidden;
    background: #000;
    display: flex;
    justify-content: center;
    align-items: center;
    font-family: 'Courier New', monospace;
    touch-action: none;
    -webkit-touch-callout: none;
    -webkit-user-select: none;
    user-select: none;
}

canvas, #gameCanvas {
    max-width: 100vw !important;
    max-height: 100dvh !important;
    max-height: 100vh !important;
    width: auto !important;
    height: auto !important;
    object-fit: contain !important;
    touch-action: none !important;
    border: 4px solid #6366f1;
    box-shadow: 0 0 20px rgba(99,102,241,0.5), inset 0 0 20px rgba(99,102,241,0.3);
    background: #0b0f19;
    box-sizing: border-box !important;
}

.scanline {
    position: fixed;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    background: linear-gradient(to bottom, rgba(255,255,255,0), rgba(255,255,255,0) 50%, rgba(0,0,0,0.25) 50%, rgba(0,0,0,0.25));
    background-size: 100% 4px;
    z-index: 10;
}

.instructions {
    position: absolute;
    top: 15px;
    color: #6366f1;
    font-size: 13px;
    font-weight: bold;
    opacity: 0.85;
    text-align: center;
    width: 100%;
    pointer-events: none;
    text-shadow: 0 0 8px #6366f1;
    letter-spacing: 1px;
    z-index: 5;
}