:root {
    --color-bg-dark: #121212;
    --color-bg-light: #1e1e1e;
    --color-bg-hover: #6200ea;
    --color-bg-hover-dark: #3700b3;
    --color-text: #ffffff;
    --color-item-bg: #333333;
    --box-shadow: 0 5px 15px rgba(0, 0, 0, 0.2);
    --border-radius: 10px;
    --transition-time: 0.3s;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: Arial, sans-serif;
    background-color: var(--color-bg-dark);
    color: var(--color-text);
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
}

.container {
    width: 400px;
    padding: 20px;
    background-color: var(--color-bg-light);
    border-radius: var(--border-radius);
    box-shadow: var(--box-shadow);
    text-align: center;
}

h1, h2 {
    margin-bottom: 20px;
}

ul {
    list-style-type: none;
    padding: 0;
}

li {
    background-color: var(--color-item-bg);
    padding: 10px;
    margin-bottom: 10px;
    border-radius: 5px;
    cursor: pointer;
    transition: background-color var(--transition-time);
}

li:hover {
    background-color: var(--color-bg-hover);
}

button {
    padding: 10px;
    background-color: var(--color-bg-hover);
    border: none;
    border-radius: 5px;
    color: var(--color-text);
    cursor: pointer;
    transition: background-color var(--transition-time);
}

button:hover {
    background-color: var(--color-bg-hover-dark);
}

.hidden {
    display: none;
}