body {
    font-family: sans-serif;
    display: flex;
    flex-direction: column;
    align-items: center;
    background-color: #f0f0f0;
}

h1 {
    color: #333;
}

.game-container {
    display: flex;
    justify-content: space-around;
    width: 80%;
    max-width: 800px;
    margin-top: 20px;
    background-color: #fff;
    padding: 20px;
    border-radius: 8px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.player {
    border: 1px solid #ccc;
    padding: 15px;
    border-radius: 5px;
    text-align: center;
    width: 45%;
}

.problem {
    font-size: 1.5em;
    margin: 15px 0;
    min-height: 1.5em; /* Ensure space even when empty */
}

input[type="number"] {
    padding: 8px;
    margin-bottom: 10px;
    width: 80%;
}

.score {
    font-weight: bold;
}

.controls {
    margin-top: 20px;
    text-align: center;
}

#start-button {
    padding: 10px 20px;
    font-size: 1em;
    cursor: pointer;
}

#timer {
    margin-top: 10px;
    font-size: 1.2em;
    font-weight: bold;
}