/* General Body Styling */
body {
    transition: background-color 0.3s;
}

/* Custom styles for the loading spinner */
.spinner {
    border: 4px solid rgba(0, 0, 0, 0.1);
    width: 36px;
    height: 36px;
    border-radius: 50%;
    border-left-color: #09f;
    margin: auto;
    animation: spin 1s ease infinite;
}

@keyframes spin {
    0% {
        transform: rotate(0deg);
    }
    100% {
        transform: rotate(360deg);
    }
}

/* Hide utility for JS */
.hidden {
    display: none;
}

/* Styling for subject cards */
.subject-card {
    transition: transform 0.2s ease-in-out, box-shadow 0.2s ease-in-out;
}

.subject-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
}

/* Styling for breadcrumbs */
#breadcrumbs a {
    color: #3b82f6; /* blue-500 */
    text-decoration: none;
}

#breadcrumbs a:hover {
    text-decoration: underline;
}

/* Styling for embedded videos to be responsive */
#video-container iframe {
    width: 100%;
    aspect-ratio: 16 / 9;
    border-radius: 8px;
}

/* Custom styles for questions */
.question-block {
    margin-bottom: 1.5rem;
    padding: 1rem;
    border: 1px solid #e5e7eb; /* gray-200 */
    border-radius: 8px;
}

.question-block button {
    margin-top: 0.5rem;
    padding: 0.5rem 1rem;
    border-radius: 6px;
    background-color: #3b82f6; /* blue-500 */
    color: white;
    border: none;
    cursor: pointer;
    transition: background-color 0.2s;
}

.question-block button:hover {
    background-color: #2563eb; /* blue-600 */
}

.feedback {
    margin-top: 0.5rem;
    font-weight: bold;
}

.feedback.correct {
    color: #16a34a; /* green-600 */
}

.feedback.incorrect {
    color: #dc2626; /* red-600 */
}