/* Reset & Base */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: Arial, sans-serif;
}

body {
    background-color: #f9f9f9;
    color: #333;
    line-height: 1.6;
}

/* Header */
header {
    background-color: #1e90ff;
    color: #fff;
    padding: 1rem 2rem;
    text-align: center;
}

header nav a {
    color: #fff;
    text-decoration: none;
    margin: 0 1rem;
    font-weight: bold;
}

header nav a:hover {
    text-decoration: underline;
}

/* Main content */
main {
    padding: 2rem;
}

h1, h2 {
    margin-bottom: 1rem;
    color: #1e90ff;
}

p {
    margin-bottom: 1rem;
}

/* Sections & Cards */
.lesson-card, .quiz-card {
    background-color: #fff;
    padding: 1rem;
    margin-bottom: 1.5rem;
    border-radius: 8px;
    box-shadow: 0 2px 6px rgba(0,0,0,0.1);
}

img {
    max-width: 100%;
    border-radius: 5px;
    margin: 0.5rem 0;
}

/* Buttons */
button {
    background-color: #1e90ff;
    color: #fff;
    border: none;
    padding: 0.7rem 1.2rem;
    border-radius: 5px;
    cursor: pointer;
    margin-top: 0.5rem;
}

button:hover {
    background-color: #0d6efd;
}

/* Quiz styles */
.quiz-question {
    margin-bottom: 1rem;
}

/* Footer */
footer {
    text-align: center;
    padding: 1rem;
    background-color: #eee;
    margin-top: 2rem;
    font-size: 0.9rem;
}

/* Responsive */
@media (max-width: 768px) {
    header nav {
        display: flex;
        flex-direction: column;
    }

    header nav a {
        margin: 0.5rem 0;
    }
}