body, html {
    margin: 0; padding: 0;
    width: 100%; height: 100%;
    overflow: hidden;
    background-color: #050a10;
}
#game-container { position: relative; width: 100vw; height: 100vh; }
#gameCanvas { display: block; }
#ui-layer {
    position: absolute; top: 0; left: 0;
    width: 100%; height: 100%;
    display: flex; justify-content: center; align-items: center;
    pointer-events: none;
}
#begin-screen {
    width: 100%; height: 100%;
    background-color: black;
    display: flex; justify-content: center; align-items: center;
    transition: opacity 1.5s ease;
    pointer-events: all;
    z-index: 10;
}
#begin-btn {
    padding: 12px 30px;
    background-color: #808080;
    color: black;
    border: 2px solid white;
    font-family: 'Courier New', Courier, monospace;
    font-weight: bold; font-size: 24px;
    cursor: pointer;
    text-shadow: -1px -1px 0 #fff, 1px -1px 0 #fff, -1px 1px 0 #fff, 1px 1px 0 #fff;
}
.hidden { opacity: 0; pointer-events: none; }