:root {
    --primary-color: #0078d4;
    /* Microsoft Blue */
    --secondary-color: #005a9e;
    /* Darker Blue */
    --bg-color: #ffffff;
    --text-color: #201f1e;
    --card-bg: #ffffff;
    --accent: #107c10;
    /* Green */
    --danger: #d13438;
    --text-muted: #605e5c;
    --light-border: #e1dfdd;
    --shadow-soft: 0 2px 8px rgba(0, 0, 0, 0.04);
    --shadow-medium: 0 8px 24px rgba(0, 0, 0, 0.08);
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    /* Force enable selection */
    user-select: auto !important;
    -webkit-user-select: auto !important;
    -moz-user-select: auto !important;
    -ms-user-select: auto !important;
}

body {
    font-family: 'Outfit', 'Segoe UI', sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    overflow: hidden;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    -webkit-user-select: none;
    -moz-user-select: none;
    -ms-user-select: none;
    user-select: none;
}

.slider-container {
    position: relative;
    width: 100%;
    height: 100%;
    overflow: hidden;
    background-color: #faf9f8;
}

.slide {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    opacity: 0;
    transition: opacity 0.5s ease-in-out, transform 0.5s ease-in-out;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    padding: 2rem;
    transform: scale(0.98);
    background: #ffffff;
    pointer-events: none;
    overflow-y: auto;
}

.slide.active {
    opacity: 1;
    transform: scale(1);
    z-index: 10;
    pointer-events: all;
}

/* Quiz Style */
.quiz-slide {
    display: block !important;
    height: 100%;
    overflow-y: auto;
    padding-top: 5rem;
    padding-bottom: 4rem;
}

.question-container {
    background-color: var(--card-bg);
    border: 1px solid var(--light-border);
    border-radius: 8px;
    padding: 2rem;
    margin-bottom: 2rem;
    text-align: left;
    box-shadow: var(--shadow-soft);
}

.question-text {
    font-size: 1.3rem;
    font-weight: 600;
    margin-bottom: 1.5rem;
    color: var(--primary-color);
}

.options {
    display: grid;
    grid-template-columns: 1fr;
    gap: 0.8rem;
    margin-bottom: 1.5rem;
}

.option {
    background-color: #f3f2f1;
    border: 1px solid transparent;
    padding: 1rem;
    border-radius: 4px;
    color: var(--text-color);
    text-align: left;
    cursor: pointer;
    transition: all 0.2s;
    font-weight: 500;
}

.option:hover {
    background-color: #deecf9;
    border-color: var(--primary-color);
    color: var(--primary-color);
}

.reveal-btn {
    background-color: var(--primary-color);
    color: #fff;
    border: none;
    padding: 0.6rem 1.2rem;
    border-radius: 4px;
    cursor: pointer;
    font-weight: 600;
    margin-top: 0.5rem;
    transition: background-color 0.2s;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

.reveal-btn:hover {
    background-color: var(--secondary-color);
}

.answer-box {
    margin-top: 1.5rem;
    padding: 1.5rem;
    background-color: #fdfdfd;
    border-left: 4px solid var(--accent);
    border: 1px solid var(--light-border);
    border-left-width: 4px;
    border-radius: 4px;
    display: none;
    box-shadow: var(--shadow-soft);
}

.answer-box.visible {
    display: block;
    animation: fadeIn 0.4s ease-out;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(-5px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.content {
    text-align: center;
    max-width: 1000px;
    width: 100%;
    margin: auto;
}

h1 {
    font-size: 3.5rem;
    margin-bottom: 1rem;
    color: var(--primary-color);
    text-shadow: none;
    font-weight: 700;
}

h2 {
    font-size: 2.2rem;
    margin-bottom: 2rem;
    color: var(--primary-color);
    border-bottom: 3px solid var(--secondary-color);
    display: inline-block;
    padding-bottom: 0.5rem;
    font-weight: 600;
}

h3 {
    color: var(--secondary-color);
    margin-bottom: 1rem;
    font-weight: 600;
}

p {
    font-size: 1.2rem;
    color: var(--text-color);
    line-height: 1.6;
    margin-bottom: 1.5rem;
}

ul {
    list-style: none;
    text-align: left;
    display: inline-block;
    margin-bottom: 1.5rem;
}

ul li {
    font-size: 1.15rem;
    margin-bottom: 0.8rem;
    padding-left: 2rem;
    position: relative;
    color: var(--text-color);
}

ul li::before {
    content: '🔹';
    position: absolute;
    left: 0;
    top: 2px;
    font-size: 0.9rem;
}

.author {
    margin-top: 4rem;
    font-size: 1.1rem;
    color: var(--text-muted);
    font-weight: 500;
    border-top: 1px solid var(--light-border);
    padding-top: 1rem;
    display: inline-block;
}

.icon-container {
    margin: 3rem 0;
}

.csharp-icon {
    font-size: 5rem;
    font-weight: bold;
    color: #fff;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    padding: 1.5rem 2rem;
    border-radius: 16px;
    box-shadow: var(--shadow-medium);
    display: inline-block;
}

/* Tables */
.data-table {
    width: 100%;
    border-collapse: separate;
    border-spacing: 0;
    margin: 2rem 0;
    background-color: var(--card-bg);
    border-radius: 8px;
    border: 1px solid var(--light-border);
    overflow: hidden;
    box-shadow: var(--shadow-soft);
}

.data-table th,
.data-table td {
    padding: 1.2rem;
    text-align: left;
    border-bottom: 1px solid var(--light-border);
}

.data-table th {
    background-color: #f3f2f1;
    color: var(--text-color);
    font-weight: 700;
}

.data-table tr:hover {
    background-color: #faf9f8;
}

.data-table code {
    background-color: #f3f2f1;
    padding: 0.2rem 0.5rem;
    border-radius: 4px;
    color: var(--primary-color);
    font-weight: 600;
}

/* Grid */
.card-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2rem;
    margin-top: 2rem;
}

.card {
    background-color: var(--card-bg);
    padding: 2rem;
    border-radius: 8px;
    box-shadow: var(--shadow-soft);
    transition: all 0.3s ease;
    border: 1px solid var(--light-border);
}

.card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-medium);
    border-color: var(--primary-color);
}

/* Feature Box */
.feature-box {
    background-color: #f0f6ff;
    padding: 2rem;
    border-radius: 8px;
    border-left: 5px solid var(--primary-color);
    text-align: left;
    margin: 1.5rem 0;
    box-shadow: var(--shadow-soft);
}

.feature-box p {
    color: var(--text-color);
    margin: 0;
}

.alert-box {
    background-color: #fde7e9;
    border-left: 5px solid var(--danger);
    padding: 1.5rem;
    border-radius: 8px;
    text-align: left;
    margin: 1.5rem 0;
}

.code-wrapper {
    margin: 2rem 0;
    text-align: left;
    border-radius: 8px;
    overflow: hidden;
    box-shadow: var(--shadow-medium);
    border: 1px solid var(--light-border);
}

.two-col {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 3rem;
    margin-top: 2rem;
    align-items: start;
}

/* Navigation */
.nav-btn {
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    background-color: rgba(255, 255, 255, 0.8);
    color: var(--primary-color);
    border: 1px solid var(--light-border);
    font-size: 1.5rem;
    width: 50px;
    height: 50px;
    display: flex;
    justify-content: center;
    align-items: center;
    cursor: pointer;
    border-radius: 50%;
    transition: all 0.2s;
    z-index: 20;
    box-shadow: var(--shadow-medium);
}

.nav-btn:hover {
    background-color: var(--primary-color);
    color: #fff;
    transform: translateY(-50%) scale(1.1);
}

.prev-btn {
    left: 30px;
}

.next-btn {
    right: 30px;
}

/* Progress Bar */
.progress-container {
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    height: 6px;
    background-color: #edebe9;
}

.progress-bar {
    height: 100%;
    background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
    width: 0%;
    transition: width 0.3s ease;
}

/* Mobile */
@media (max-width: 768px) {
    h1 {
        font-size: 2.2rem;
    }

    h2 {
        font-size: 1.8rem;
    }

    .two-col {
        grid-template-columns: 1fr;
        gap: 1.5rem;
    }

    .slide {
        padding: 1rem;
    }

    .nav-btn {
        width: 40px;
        height: 40px;
        font-size: 1.2rem;
    }
}

/* --- MODAL STYLES --- */
.modal {
    display: none;
    position: fixed;
    z-index: 2000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.6);
    backdrop-filter: blur(4px);
}

.modal-content {
    background-color: #fefefe;
    margin: 5% auto;
    padding: 2.5rem;
    border: 1px solid var(--light-border);
    width: 90%;
    max-width: 800px;
    border-radius: 12px;
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.3);
    position: relative;
    /* ... existing animation code ... */
    animation: modalSlideIn 0.4s cubic-bezier(0.16, 1, 0.3, 1);
    
    /* Scroll fix */
    max-height: 85vh;
    overflow-y: auto;
}

/* Scrollbar styling for modal */
.modal-content::-webkit-scrollbar {
    width: 8px;
}

.modal-content::-webkit-scrollbar-track {
    background: #f1f1f1;
    border-radius: 4px;
}

.modal-content::-webkit-scrollbar-thumb {
    background: #c1c1c1;
    border-radius: 4px;
}

.modal-content::-webkit-scrollbar-thumb:hover {
    background: #a8a8a8;
}

/* Copy Button Style */
.copy-btn {
    position: absolute;
    top: 20px;
    right: 70px; /* Positioned to the left of the close button */
    background-color: #f3f2f1;
    color: var(--primary-color);
    border: 1px solid var(--light-border);
    padding: 6px 12px;
    border-radius: 4px;
    cursor: pointer;
    font-size: 0.9rem;
    font-weight: 600;
    transition: all 0.2s;
    display: flex;
    align-items: center;
    gap: 5px;
    z-index: 10;
}

.copy-btn:hover {
    background-color: var(--primary-color);
    color: white;
    border-color: var(--primary-color);
}

.copy-btn i {
    font-style: normal;
}

@keyframes modalSlideIn {
    from {
        opacity: 0;
        transform: translateY(-50px) scale(0.95);
    }

    to {
        opacity: 1;
        transform: translateY(0) scale(1);
    }
}

.close-modal {
    color: #aaa;
    position: absolute; /* Fix close button position */
    top: 20px;
    right: 25px;
    font-size: 30px;
    font-weight: bold;
    cursor: pointer;
    line-height: 1;
    z-index: 20;
}

.close-modal:hover {
    color: var(--danger);
}

.example-btn {
    margin-top: 1.5rem;
    padding: 0.8rem 1.5rem;
    background-color: var(--secondary-color);
    color: #fff;
    border: none;
    border-radius: 6px;
    cursor: pointer;
    font-weight: 600;
    font-size: 1rem;
    transition: all 0.2s;
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.1);
    display: inline-flex;
    align-items: center;
    gap: 8px;
}

.example-btn:hover {
    background-color: var(--primary-color);
    transform: translateY(-2px);
    box-shadow: 0 6px 15px rgba(0, 0, 0, 0.15);
}

/* Close Button Styles */
#close-presentation-btn {
    position: absolute;
    top: 25px;
    right: 35px;
    background: rgba(0, 0, 0, 0.05);
    border: 1px solid rgba(0, 0, 0, 0.1);
    color: #323130;
    font-size: 1.2rem;
    width: 45px;
    height: 45px;
    border-radius: 50%;
    cursor: pointer;
    z-index: 1000;
    display: flex;
    justify-content: center;
    align-items: center;
    transition: all 0.3s ease;
}

#close-presentation-btn:hover {
    background-color: #d13438;
    color: white;
    border-color: #d13438;
    transform: rotate(90deg);
    box-shadow: 0 4px 12px rgba(209, 52, 56, 0.3);
}

/* Slide Counter */
#slide-counter {
    position: absolute;
    bottom: 20px;
    right: 20px;
    font-size: 1rem;
    font-weight: 600;
    color: var(--text-color);
    background-color: rgba(255, 255, 255, 0.9);
    padding: 5px 12px;
    border-radius: 20px;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
    z-index: 1000;
    font-family: 'Outfit', sans-serif;
    border: 1px solid var(--light-border);
}

/* Interactive Quiz Styling */
.interactive-option {
    cursor: pointer;
    transition: all 0.2s ease;
    border: 2px solid #e1dfdd;
    position: relative;
    /* For pseudo-elements */
}

.interactive-option:hover {
    background-color: #f3f2f1;
    border-color: #c8c6c4;
    transform: translateX(5px);
}

.interactive-option.correct {
    background-color: #dff6dd !important;
    border-color: #107c10 !important;
    color: #0b5a0b;
    font-weight: 600;
}

.interactive-option.incorrect {
    background-color: #fde7e9 !important;
    border-color: #d13438 !important;
    color: #a4262c;
}

.interactive-option.disabled {
    pointer-events: none;
    cursor: default;
}

/* When wrong answer selected, show correct one */
.interactive-option.show-correct {
    background-color: #dff6dd !important;
    border-color: #107c10 !important;
    box-shadow: 0 0 10px rgba(16, 124, 16, 0.3);
}

.interactive-option.show-correct::after {
    content: "✅";
    position: absolute;
    right: 15px;
    font-size: 1.2rem;
}


/* Slide Jump Controls */
#slide-jump-input:focus {
    transform: scale(1.05);
    border-color: #0078d4;
    transition: all 0.2s;
}

#slide-jump-input::placeholder {
    color: #bbb;
    font-size: 0.9rem;
}

.jump-wrapper {
    transition: transform 0.2s;
}

.jump-wrapper:hover {
    transform: translateY(-2px);
}