body {
    font-family: courier;
    text-transform: uppercase;
    background-color: #f4f4f4;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    margin: 0;
}

.alert {
    position: absolute;
    top: 10px;
    left: 10px;
    padding: 20px;
    background-color: white;
    font-family: courier;
    text-transform: uppercase;
    color: #3498db;
    margin-bottom: 15px;
    border-radius: 5px;
}

.alert .closebtn {
    margin-left: 15px;
    color: #2ecc71;
    font-weight: bold;
    float: right;
    font-size: 20px;
    line-height: 20px;
    cursor: pointer;
}

.alert .closebtn:hover {
    color: #27ae60;
}

.container {
    background-color: #fff;
    padding: 30px;
    border-radius: 8px;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
    text-align: center;
}

h1 {
    color: #3498db;
    margin-bottom: 20px;
}

p {
    font-size: 1.2em;
    margin-bottom: 15px;
    color: #555;
}

input[type="number"] {
    padding: 10px;
    font-size: 1em;
    border: 1px solid #ccc;
    border-radius: 4px;
    margin-right: 10px;
}

button {
    background-color: #2ecc71;
    color: white;
    padding: 10px 20px;
    font-size: 1em;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    transition: background-color 0.3s ease;
    margin-top: 10px;
}

button:hover {
    background-color: #27ae60;
}

.feedback {
    margin-top: 15px;
    font-weight: bold;
}

.correct {
    color: green;
}

.incorrect {
    color: red;
}

#timer {
    font-size: 1.5em;
    font-weight: bold;
    color: #e74c3c;
    margin-bottom: 10px;
    display: none;
}

#start-button {
    display: block;
    margin: 20px auto;
}

#question-area {
    display: none;
}

a {
    display: inline-block;
    background-color: #3498db;
    color: white;
    padding: 10px 20px;
    text-decoration: none;
    border-radius: 4px;
    transition: background-color 0.3s ease;
}

a:hover {
    background-color: #2980b9;
}

.score {
    font-size: 1.5em;
    font-weight: bold;
    color: #2ecc71;
    margin-bottom: 20px;
}