* {
    box-sizing: border-box;
}

body {
    margin: 0;
    padding: 1rem;
    font-family: Arial, Helvetica, sans-serif;
    overflow: hidden;
    height: 100vh;
}

#controls {
    margin-bottom: 0.75rem;
}

#message-display {
    font-size: 1.25rem;
    font-weight: bold;
    height: 1.5rem;
    margin-bottom: 0.75rem;
}

#game-area {
    position: relative;
    width: 100%;
    height: calc(100vh - 120px);
}

.memory-btn {
    width: 10em;
    height: 5em;
    font-size: 1rem;
    font-weight: bold;
    cursor: pointer;
    border: 1px solid #222;
    border-radius: 4px;
}