body {
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}


#sidebar {
    scrollbar-width: thin;
    scrollbar-color: #4A5568 #2D3748; /* thumb track */
}

#sidebar::-webkit-scrollbar {
    width: 8px;
}

#sidebar::-webkit-scrollbar-track {
    background: #2D3748; /* bg-slate-800 */
}

#sidebar::-webkit-scrollbar-thumb {
    background-color: #4A5568; /* a bit lighter than track */
    border-radius: 4px;
    border: 2px solid #2D3748; /* track color to create a thin border */
}

#main-nav ul {
    list-style: none;
    padding: 0;
}

#main-nav li a {
    display: block;
    padding: 0.6rem 1rem; /* Slightly reduced padding for more items */
    border-radius: 0.375rem;
    transition: background-color 0.2s ease-in-out, color 0.2s ease-in-out;
    color: #cbd5e1; /* slate-300 */
    font-weight: 500;
}

#main-nav li a:hover {
    background-color: #334155; /* slate-700 */
    color: #ffffff;
}

#main-nav li a.active {
    background-color: #0ea5e9; /* sky-500 */
    color: #ffffff;
    font-weight: 600;
}

#main-nav li a i {
    margin-right: 0.75rem;
    width: 1.1rem; /* Slightly smaller icons */
    height: 1.1rem;
}


.prose h2 {
    font-size: 1.875rem; /* text-3xl */
    margin-bottom: 1.5rem;
}

.prose h3 {
    font-size: 1.5rem; /* text-2xl */
    margin-bottom: 0.75rem;
}

.prose p, 
.prose ul, 
.prose ol {
    font-size: 1rem; 
    line-height: 1.75; 
}

.prose ul, .prose ol {
    margin-left: 1.5rem;
}

.prose strong {
    color: #1e293b; 
}

.prose section {
    scroll-margin-top: 2rem; 
}

#sidebar-toggle {
    display: none; 
}


.quiz-options label.correct-answer {
    background-color: #d1fae5; /* Tailwind green-100 */
    border-left: 4px solid #10b981; /* Tailwind green-500 */
}
.quiz-options label.correct-answer-reveal {
    background-color: #d1fae5; /* Tailwind green-100 */
    border: 1px solid #10b981; /* Tailwind green-500 */
    font-weight: bold;
}
.quiz-options label.incorrect-answer {
    background-color: #fee2e2; /* Tailwind red-100 */
    border-left: 4px solid #ef4444; /* Tailwind red-500 */
}
.quiz-question .feedback .lucide-check-circle { color: #10b981; }
.quiz-question .feedback .lucide-x-circle { color: #ef4444; }


.faq-item .faq-question .faq-icon {
    transition: transform 0.3s ease-in-out;
}
.faq-item .faq-question[aria-expanded="true"] .faq-icon {
    transform: rotate(180deg);
}

.interactive-step {
    font-size: 0.875rem;
}

.arrow {
    font-size: 1.25rem;
}


@media (max-width: 767px) { 
    #sidebar {
        transform: translateX(-100%);
        z-index: 40; 
    }
    #sidebar.open {
        transform: translateX(0);
    }
    #main-content {
        margin-left: 0;
        max-width: 100%;
    }
    #sidebar-toggle {
        display: block;
    }
    .prose h2 {
        font-size: 1.5rem; 
    }
    .prose h3 {
        font-size: 1.25rem;
    }
     #main-nav li a {
        padding: 0.5rem 0.75rem;
        font-size: 0.875rem;
    }
    #main-nav li a i {
        margin-right: 0.5rem;
        width: 1rem;
        height: 1rem;
    }
}