@font-face {
    font-family: 'Terminal';
    src: local('Courier New'), local('Courier'), monospace;
}

body {
    margin: 0;
    padding: 0;
    background-color: #008080; /* Windows 3.1 Teal */
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    font-family: 'Terminal', monospace;
    overflow: hidden;
}

#os-shell {
    width: 620px;
    padding: 10px;
}

#window {
    background-color: #c0c0c0;
    border: 2px solid #fff;
    box-shadow: 2px 2px 0 #000, -2px -2px 0 #808080;
}

#title-bar {
    background: linear-gradient(90deg, #000080 0%, #0821D2 100%);
    color: white;
    padding: 3px 6px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-weight: bold;
    font-size: 14px;
}

#controls button {
    width: 16px;
    height: 14px;
    background: #c0c0c0;
    border: 1px solid #fff;
    box-shadow: 1px 1px 0 #000;
    font-size: 8px;
    line-height: 8px;
    margin-left: 2px;
}

#game-container {
    position: relative;
    width: 600px;
    height: 600px;
    background-color: #000;
    margin: 4px;
    border: 2px solid #808080;
    overflow: hidden;
}

canvas {
    display: block;
    width: 600px;
    height: 600px;
}

#ui-overlay {
    position: absolute;
    top: 10px;
    left: 10px;
    color: #00ff00;
    text-shadow: 1px 1px 2px #000;
    pointer-events: none;
}

.stat {
    margin-bottom: 5px;
    font-size: 18px;
}

.overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.85);
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    color: #fff;
    text-align: center;
    z-index: 10;
}

#start-screen h1, #game-over-screen h1 {
    color: #00ffff;
    margin-bottom: 20px;
    font-size: 32px;
    text-shadow: 2px 2px 0 #ff00ff;
}

button#start-btn, button#restart-btn {
    margin-top: 30px;
    padding: 10px 20px;
    background: #c0c0c0;
    border: 3px solid #fff;
    box-shadow: 3px 3px 0 #000, -1px -1px 0 #808080;
    font-family: 'Terminal', monospace;
    font-weight: bold;
    cursor: pointer;
}

#game-container:focus {
    outline: none;
    border-color: #00ffff;
}