:root {
    --bg-black: #000000;
    --font-mono: 'Courier New', Courier, monospace;
    --font-ui: 'Tahoma', 'Verdana', sans-serif;
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    user-select: none; /* OS feel */
}

body, html {
    width: 100%;
    height: 100%;
    overflow: hidden;
    background-color: var(--bg-black);
    font-family: var(--font-mono);
}

#app-root {
    width: 100vw;
    height: 100vh;
    position: relative;
}

.os-container {
    width: 100%;
    height: 100%;
    position: absolute;
    top: 0;
    left: 0;
    display: none; /* Hidden by default */
    z-index: 10;
}

.os-container.active {
    display: block;
}

/* CRT Overlay Effect (Global opt-in) */
.crt::before {
    content: " ";
    display: block;
    position: absolute;
    top: 0;
    left: 0;
    bottom: 0;
    right: 0;
    background: linear-gradient(rgba(18, 16, 16, 0) 50%, rgba(0, 0, 0, 0.25) 50%), linear-gradient(90deg, rgba(255, 0, 0, 0.06), rgba(0, 255, 0, 0.02), rgba(0, 0, 255, 0.06));
    z-index: 9999;
    background-size: 100% 2px, 3px 100%;
    pointer-events: none;
}