/* General Styles */
body {
    font-family: 'Noto Sans', sans-serif;
    margin: 0;
    padding: 0;
    background-color: #fff;
    color: #333;
    line-height: 1.6;
}

/* Header Styles */
header {
    background-color: #303f9f;
    color: #fff;
    padding: 1rem 0;
    text-align: center;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.2);
}

header h1 {
    font-size: 2rem;
    margin-bottom: 0.5rem;
}

/* Navigation Styles */
nav ul {
    padding: 0;
    list-style: none;
    display: flex;
    justify-content: center;
}

nav ul li {
    margin: 0 1rem;
}

nav a {
    color: #fff;
    text-decoration: none;
    font-size: 1.1rem;
    transition: color 0.3s ease;
}

nav a:hover {
    color: #9fa8da;
}

/* Main Content Styles */
main {
    padding: 1.5rem;
    margin: 0 auto;
    max-width: 1000px;
}

section {
    margin-bottom: 1.5rem;
    background-color: #fff;
    padding: 1.2rem;
    border-radius: 6px;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
}

section h2 {
    color: #303f9f;
    font-size: 1.6rem;
    margin-bottom: 0.8rem;
    border-bottom: 2px solid #9fa8da;
    padding-bottom: 0.4rem;
}

/* Filter Styles */
#filters {
    display: flex;
    flex-direction: column;
    gap: 0.8rem;
}

#filters label {
    display: block;
    margin-bottom: 0.3rem;
    font-size: 0.9rem;
    color: #546e7a;
}

#filters select,
#filters input[type="checkbox"] {
    width: 100%;
    padding: 0.6rem;
    margin-bottom: 0.8rem;
    border: 1px solid #ccc;
    border-radius: 4px;
    box-sizing: border-box;
    font-size: 0.9rem;
}

@media (min-width: 769px) {
    #filters {
        grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
        gap: 0.8rem;
    }
}

/* Question List Styles */
#questions-list ul {
    list-style: none;
    padding: 0;
}

#questions-list li {
    background-color: #f5f5f5;
    border: 1px solid #e0e0e0;
    margin-bottom: 0.8rem;
    padding: 0.8rem;
    border-radius: 4px;
    font-size: 1rem;
}

#questions-list li strong {
    color: #1a237e;
}

#questions-list li ul {
    padding-left: 20px;
}

#questions-list li ul li {
    background-color: transparent;
    border: none;
    padding: 0.2rem 0;
    margin-bottom: 0;
    list-style-type: disc;
}

/* Flashcard Styles */
#flashcard-container {
    text-align: center;
}

#flashcard {
    background-color: #fff;
    border: 1px solid #9fa8da;
    padding: 1.5rem;
    margin: 1.5rem auto;
    max-width: 600px;
    border-radius: 10px;
    cursor: pointer;
    font-size: 1.1rem;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

#flashcard .question {
    font-size: 1.2rem;
    color: #303f9f;
    margin-bottom: 0.8rem;
}

#flashcard .answer {
    margin-top: 1rem;
    color: #3f51b5;
}

#flashcard .answer ul {
    padding-left: 20px;
}

#flashcard .answer ul li {
    list-style-type: disc;
}

#next-question {
    background-color: #303f9f;
    color: #fff;
    border: none;
    padding: 0.8rem 1.5rem;
    font-size: 1rem;
    border-radius: 5px;
    cursor: pointer;
    transition: background-color 0.3s ease;
}

#next-question:hover {
    background-color: #3f51b5;
}

.hidden {
    display: none;
}

/* Footer Styles */
footer {
    text-align: center;
    padding: 1rem 0;
    background-color: #303f9f;
    color: #fff;
    position: relative;
    width: 100%;
    font-size: 0.9rem;
}

footer a {
    color: #9fa8da;
    text-decoration: none;
    transition: color 0.3s ease;
}

footer a:hover {
    color: #fff;
}

/* Accessibility Improvements */
button,
select,
input[type="checkbox"] {
    cursor: pointer;
    -webkit-appearance: none;
    -moz-appearance: none;
    appearance: none;
}

/* Responsive Design */
@media (max-width: 768px) {
    main {
        padding: 1rem;
    }

    nav ul {
        flex-direction: column;
        align-items: center;
    }

    nav ul li {
        margin: 0.5rem 0;
    }

    #filters {
        grid-template-columns: 1fr;
    }

    #filters label {
        font-size: 0.9rem;
    }

    #filters select,
    #filters input[type="checkbox"] {
        padding: 0.7rem;
        font-size: 1rem;
    }

    #flashcard {
        font-size: 1rem;
        padding: 1.2rem;
    }

    #flashcard .question {
        font-size: 1.1rem;
    }

    #next-question {
        font-size: 1.1rem;
    }
}