:root {
    --primary-color: #7E57C2; 
    --background-color: #FDFBFE;
    --text-color: #1C1B1F;
    --card-bg: #FFFFFF;
}

body {
    font-family: 'Roboto', sans-serif;
    background-color: var(--background-color);
    color: var(--text-color);
    margin: 0;
    padding: 20px;
    line-height: 1.6;
}

.container {
    max-width: 800px;
    margin: 0 auto;
    padding-bottom: 50px;
}

h1, h2 {
    color: var(--primary-color);
}

details {
    background-color: var(--card-bg);
    border: 1px solid #e0e0e0;
    border-radius: 8px;
    padding: 15px;
    margin-bottom: 10px;
    box-shadow: 0 2px 5px rgba(0,0,0,0.05);
    cursor: pointer;
    transition: all 0.3s ease;
}

details[open] {
    border-color: var(--primary-color);
}

summary {
    font-weight: bold;
    list-style: none; 
    display: flex;
    justify-content: space-between;
    align-items: center;
}

summary::after {
    content: '+';
    font-size: 1.5em;
    color: var(--primary-color);
}

details[open] summary::after {
    content: '-';
}

nav {
    margin-bottom: 40px;
    padding: 10px;
    border-bottom: 1px solid #eee;
    display: flex;
    justify-content: space-between;
}

nav a {
    text-decoration: none;
    color: var(--text-color);
    margin-right: 15px;
    font-weight: 500;
}

nav a.active {
    color: var(--primary-color);
    font-weight: bold;
}