:root {
    --background-color: #00185f;
    --text-color: #fff;
    --box-shadow: #3f59a5;
}

body {
    font-family: 'Trebuchet MS', 'Lucida Sans Unicode', 'Lucida Grande', 'Lucida Sans', Arial, sans-serif;
    background-color: var(--background-color);
    color: var(--text-color);
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    margin: 0;
}

.container {
    background-color: #011c6d;
    padding: 30px;
    border-radius: 12px;
    box-shadow: 0 8px 16px var(--box-shadow);
    text-align: center;
    width: 330px;
}

h1 {
    color: var(--text-color);
    margin-bottom: 20px;
}

input[type="number"] {
    padding: 10px;
    width: 100%;
    margin: 10px 0;
    font-size: 16px;
    border-radius: 6px;
    border: 1px solid var(--box-shadow);
    background-color: #001a5a;
    color: var(--text-color);
}

button {
    padding: 10px 20px;
    margin-top: 10px;
    border: none;
    border-radius: 6px;
    font-size: 16px;
    cursor: pointer;
    background-color: #40d0e0;
    color: white;
    transition: background-color 0.3s;
}

button:hover {
    background-color: white;
    color: #40d0e0;
    transition: 0.5s;
}

.reset-btn {
    background-color: #e7a73a;
}

.reset-btn:hover {
    background-color: white;
    color: #e7a73a;
    transition: 0.5s;
}

#message {
    margin: 15px 0;
    font-size: 18px;
}

.difficulty {
    margin-bottom: 20px;
}

select {
    padding: 8px;
    border-radius: 6px;
    border: 1px solid var(--box-shadow);
    background-color: #001a5a;
    color: var(--text-color);
}