/* --- Modern CSS variables & Theme tokens --- */
:root {
    --bg-primary: #0b0f19;
    --bg-secondary: #161c2d;
    --bg-tertiary: #1f283e;
    --border-color: rgba(255, 255, 255, 0.08);
    --text-primary: #f3f4f6;
    --text-secondary: #9ca3af;
    --accent-blue: #3b82f6;
    --accent-blue-hover: #2563eb;
    --accent-purple: #8b5cf6;
    --accent-purple-hover: #7c3aed;
    --accent-green: #10b981;
    --accent-red: #ef4444;
    --card-shadow: 0 8px 32px 0 rgba(0, 0, 0, 0.37);
    --glass-bg: rgba(22, 28, 45, 0.7);
    --glass-border: rgba(255, 255, 255, 0.06);
    --glass-blur: blur(12px);
    --font-sans: 'Outfit', 'Plus Jakarta Sans', system-ui, sans-serif;
    --font-mono: 'JetBrains Mono', monospace;
    --sidebar-width: 280px;
    --glow-blue: 0 0 15px rgba(59, 130, 246, 0.45);
    --glow-purple: 0 0 15px rgba(139, 92, 246, 0.45);
}

/* --- Light Mode adjustments --- */
.light-mode {
    --bg-primary: #f8fafc;
    --bg-secondary: #ffffff;
    --bg-tertiary: #f1f5f9;
    --border-color: rgba(0, 0, 0, 0.06);
    --text-primary: #0f172a;
    --text-secondary: #64748b;
    --accent-blue: #2563eb;
    --accent-blue-hover: #1d4ed8;
    --accent-purple: #7c3aed;
    --accent-purple-hover: #6d28d9;
    --accent-green: #059669;
    --accent-red: #dc2626;
    --card-shadow: 0 10px 25px -5px rgba(0, 0, 0, 0.05), 0 8px 10px -6px rgba(0, 0, 0, 0.05);
    --glass-bg: rgba(255, 255, 255, 0.85);
    --glass-border: rgba(0, 0, 0, 0.06);
    --glow-blue: 0 0 12px rgba(37, 99, 235, 0.25);
    --glow-purple: 0 0 12px rgba(124, 58, 246, 0.25);
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    font-family: var(--font-sans);
}

body {
    background-color: var(--bg-primary);
    color: var(--text-primary);
    min-height: 100vh;
    overflow-x: hidden;
    transition: background-color 0.3s ease, color 0.3s ease;
}

.app-container {
    display: flex;
    min-height: 100vh;
    position: relative;
}

/* --- Sidebar Styling --- */
.sidebar {
    width: var(--sidebar-width);
    background-color: var(--bg-secondary);
    border-right: 1px solid var(--border-color);
    padding: 1.75rem;
    display: flex;
    flex-direction: column;
    position: fixed;
    height: 100vh;
    left: 0;
    top: 0;
    z-index: 100;
}

.sidebar-header {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    margin-bottom: 2rem;
}

.logo-icon {
    background: linear-gradient(135deg, var(--accent-blue), var(--accent-purple));
    color: #ffffff;
    width: 40px;
    height: 40px;
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 1.25rem;
    box-shadow: var(--glow-blue);
}

.logo-text h1 {
    font-size: 1.15rem;
    font-weight: 700;
    letter-spacing: -0.025em;
    line-height: 1.2;
}

.logo-text span {
    font-size: 0.75rem;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.progress-section {
    background-color: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 1rem;
    margin-bottom: 2rem;
}

.progress-labels {
    display: flex;
    justify-content: space-between;
    font-size: 0.8rem;
    color: var(--text-secondary);
    margin-bottom: 0.5rem;
    font-weight: 500;
}

.progress-bar-container {
    background-color: var(--bg-primary);
    height: 6px;
    border-radius: 10px;
    overflow: hidden;
}

.progress-bar {
    width: 0%;
    height: 100%;
    background: linear-gradient(90deg, var(--accent-blue), var(--accent-purple));
    border-radius: 10px;
    transition: width 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}

.nav-menu {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
    flex-grow: 1;
    overflow-y: auto;
}

.nav-item {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 0.85rem 1rem;
    border-radius: 10px;
    color: var(--text-secondary);
    text-decoration: none;
    font-weight: 500;
    font-size: 0.9rem;
    transition: all 0.2s ease;
    border: 1px solid transparent;
}

.nav-item:hover {
    color: var(--text-primary);
    background-color: var(--bg-tertiary);
}

.nav-item.active {
    background-color: var(--bg-tertiary);
    color: var(--text-primary);
    border-color: var(--border-color);
    box-shadow: inset 3px 0 0 0 var(--accent-blue);
}

.nav-item.completed {
    box-shadow: inset 3px 0 0 0 var(--accent-green);
}

.nav-item.tool-highlight {
    background: linear-gradient(135deg, rgba(139, 92, 246, 0.1), rgba(59, 130, 246, 0.1));
    border: 1px solid rgba(139, 92, 246, 0.2);
}

.nav-item.tool-highlight:hover {
    background: linear-gradient(135deg, rgba(139, 92, 246, 0.15), rgba(59, 130, 246, 0.15));
}

.step-num {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 22px;
    height: 22px;
    border-radius: 6px;
    background-color: var(--bg-primary);
    font-size: 0.75rem;
    font-weight: 600;
}

.nav-item.completed .step-num {
    background-color: var(--accent-green);
    color: #ffffff;
}

.sidebar-footer {
    padding-top: 1.5rem;
    border-top: 1px solid var(--border-color);
}

.status-indicator {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 0.75rem;
    color: var(--text-secondary);
}

.status-dot {
    width: 8px;
    height: 8px;
    border-radius: 50%;
}

.status-dot.online {
    background-color: var(--accent-green);
    box-shadow: 0 0 8px var(--accent-green);
}

/* --- Main Content Layout --- */
.main-content {
    margin-left: var(--sidebar-width);
    flex-grow: 1;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

.content-header {
    height: 70px;
    border-bottom: 1px solid var(--border-color);
    padding: 0 2rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
    background-color: var(--bg-primary);
    position: sticky;
    top: 0;
    z-index: 90;
}

.breadcrumb {
    font-weight: 600;
    color: var(--text-primary);
}

.theme-toggle {
    cursor: pointer;
    width: 40px;
    height: 40px;
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    background-color: var(--bg-secondary);
    border: 1px solid var(--border-color);
    color: var(--text-secondary);
    transition: all 0.2s ease;
}

.theme-toggle:hover {
    color: var(--text-primary);
    border-color: var(--accent-blue);
}

.theme-toggle .moon-icon {
    display: block;
    width: 20px;
    height: 20px;
}

.theme-toggle .sun-icon {
    display: none;
    width: 20px;
    height: 20px;
}

.light-mode .theme-toggle .moon-icon {
    display: none;
}

.light-mode .theme-toggle .sun-icon {
    display: block;
}

.scroll-container {
    padding: 2rem;
    max-width: 1100px;
    margin: 0 auto;
    width: 100%;
    flex-grow: 1;
}

/* --- Animations & Transitions --- */
.content-section {
    display: none;
    opacity: 0;
    transform: translateY(15px);
    transition: opacity 0.3s ease, transform 0.3s ease;
}

.content-section.active {
    display: block;
    opacity: 1;
    transform: translateY(0);
}

/* --- Card Styles --- */
.card {
    background-color: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: 16px;
    padding: 2rem;
    margin-bottom: 1.5rem;
    box-shadow: var(--card-shadow);
}

.card h2 {
    font-size: 1.6rem;
    font-weight: 700;
    margin-bottom: 1rem;
    letter-spacing: -0.02em;
}

.card p {
    color: var(--text-secondary);
    line-height: 1.6;
    margin-bottom: 1.5rem;
}

.card-header-with-badge {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1.25rem;
}

.card-header-with-badge h2 {
    margin-bottom: 0;
}

.badge {
    background: linear-gradient(135deg, rgba(59, 130, 246, 0.1), rgba(139, 92, 246, 0.1));
    border: 1px solid rgba(59, 130, 246, 0.2);
    color: var(--accent-blue);
    padding: 0.35rem 0.75rem;
    border-radius: 8px;
    font-size: 0.8rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.badge.step-badge {
    color: var(--accent-purple);
    border-color: rgba(139, 92, 246, 0.2);
}

/* --- Welcome Hero Card --- */
.hero-card {
    background: linear-gradient(135deg, rgba(22, 28, 45, 0.9), rgba(11, 15, 25, 0.9));
    border: 1px solid var(--border-color);
    border-radius: 20px;
    padding: 3rem 2.5rem;
    margin-bottom: 1.5rem;
    position: relative;
    overflow: hidden;
    box-shadow: var(--card-shadow);
}

.hero-card::before {
    content: '';
    position: absolute;
    top: -50%;
    right: -20%;
    width: 350px;
    height: 350px;
    background: radial-gradient(circle, rgba(139, 92, 246, 0.15) 0%, transparent 70%);
    pointer-events: none;
}

.hero-card h2 {
    font-size: 2.2rem;
    font-weight: 800;
    margin-top: 1rem;
    margin-bottom: 0.5rem;
    letter-spacing: -0.03em;
    background: linear-gradient(to right, var(--text-primary), var(--text-secondary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.hero-card .subtitle {
    font-size: 1.1rem;
    margin-bottom: 2.5rem;
}

.objective-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1.25rem;
}

.objective-card {
    background-color: rgba(255, 255, 255, 0.03);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 1.25rem;
    transition: transform 0.2s ease, border-color 0.2s ease;
}

.objective-card:hover {
    transform: translateY(-2px);
    border-color: rgba(59, 130, 246, 0.3);
}

.card-icon {
    font-size: 1.75rem;
    margin-bottom: 0.75rem;
}

.objective-card h4 {
    font-size: 0.95rem;
    font-weight: 600;
    margin-bottom: 0.35rem;
}

.objective-card p {
    font-size: 0.8rem;
    margin-bottom: 0;
}

/* --- List Styling --- */
.styled-list {
    margin-left: 1.25rem;
    margin-bottom: 1.5rem;
    color: var(--text-secondary);
}

.styled-list li {
    margin-bottom: 0.75rem;
    line-height: 1.6;
}

.styled-list li strong {
    color: var(--text-primary);
}

.styled-list ul {
    margin-left: 1.5rem;
    margin-top: 0.5rem;
    list-style-type: circle;
}

.styled-list ul li {
    margin-bottom: 0.35rem;
}

/* --- Code Block Formatting --- */
.code-wrapper {
    background-color: var(--bg-primary);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    position: relative;
    margin-bottom: 1.5rem;
    overflow: hidden;
}

.code-wrapper pre {
    padding: 1.25rem;
    overflow-x: auto;
    margin: 0;
}

.code-wrapper code {
    font-family: var(--font-mono);
    font-size: 0.85rem;
    color: #38bdf8;
    line-height: 1.5;
}

.copy-btn {
    position: absolute;
    top: 0.75rem;
    right: 0.75rem;
    background-color: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    color: var(--text-secondary);
    padding: 0.35rem 0.75rem;
    border-radius: 6px;
    font-size: 0.75rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s ease;
}

.copy-btn:hover {
    color: var(--text-primary);
    border-color: var(--accent-blue);
}

.copy-btn.copied {
    background-color: var(--accent-green);
    color: #ffffff;
    border-color: var(--accent-green);
}

/* --- Alerts & Callouts --- */
.info-alert {
    background-color: rgba(59, 130, 246, 0.05);
    border-left: 4px solid var(--accent-blue);
    padding: 1rem 1.25rem;
    border-radius: 0 10px 10px 0;
    margin-bottom: 1.5rem;
    font-size: 0.9rem;
    line-height: 1.5;
}

.info-alert strong {
    color: var(--text-primary);
}

.concept-callout {
    background-color: rgba(139, 92, 246, 0.04);
    border: 1px solid rgba(139, 92, 246, 0.15);
    border-radius: 12px;
    padding: 1.5rem;
    margin-bottom: 1.5rem;
}

.concept-callout h4 {
    color: var(--accent-purple);
    font-weight: 700;
    margin-bottom: 1rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.comparison-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1.25rem;
}

@media (max-width: 768px) {
    .comparison-grid {
        grid-template-columns: 1fr;
    }
}

.comp-box {
    background-color: var(--bg-primary);
    border: 1px solid var(--border-color);
    border-radius: 10px;
    padding: 1.25rem;
}

.comp-box h5 {
    font-size: 0.95rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
}

.container-text {
    color: var(--accent-blue);
}

.ou-text {
    color: var(--accent-purple);
}

.comp-box p {
    font-size: 0.85rem;
    margin-bottom: 0;
}

/* --- Tabs System --- */
.tab-container {
    margin-bottom: 1.5rem;
}

.tab-headers {
    display: flex;
    gap: 0.5rem;
    border-bottom: 1px solid var(--border-color);
    margin-bottom: 1.25rem;
}

.tab-button {
    background: none;
    border: none;
    outline: none;
    color: var(--text-secondary);
    padding: 0.75rem 1.25rem;
    font-weight: 600;
    font-size: 0.85rem;
    cursor: pointer;
    border-bottom: 2px solid transparent;
    transition: all 0.2s ease;
}

.tab-button:hover {
    color: var(--text-primary);
}

.tab-button.active {
    color: var(--accent-blue);
    border-bottom-color: var(--accent-blue);
}

.tab-content {
    display: none;
}

.tab-content.active {
    display: block;
}

/* --- Form / Customization Layouts --- */
.task-params-box {
    background: linear-gradient(135deg, rgba(22, 28, 45, 0.4), rgba(31, 40, 62, 0.4));
    margin-bottom: 2rem;
}

.form-row {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 1rem;
    margin-top: 1rem;
}

.form-col {
    display: flex;
    flex-direction: column;
    gap: 0.35rem;
}

.form-col label {
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    color: var(--text-secondary);
    letter-spacing: 0.05em;
}

.form-col input, .sim-col select {
    background-color: var(--bg-primary);
    border: 1px solid var(--border-color);
    padding: 0.65rem 0.85rem;
    border-radius: 8px;
    color: var(--text-primary);
    font-size: 0.85rem;
    outline: none;
    transition: border-color 0.2s ease;
}

.form-col input:focus, .sim-col select:focus {
    border-color: var(--accent-blue);
    box-shadow: 0 0 0 2px rgba(59, 130, 246, 0.15);
}

/* --- Quick Quiz Widget --- */
.quick-quiz-box {
    background-color: var(--bg-primary);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 1.25rem;
    margin-top: 1.5rem;
}

.quick-quiz-box h5 {
    color: var(--accent-blue);
    font-size: 0.9rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
}

.quick-quiz-box p {
    font-size: 0.85rem;
    margin-bottom: 1rem;
}

.quiz-choices {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.quiz-btn {
    background-color: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 0.65rem 1rem;
    color: var(--text-primary);
    text-align: left;
    font-size: 0.8rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s ease;
}

.quiz-btn:hover {
    background-color: var(--border-color);
    border-color: var(--text-secondary);
}

.quiz-btn.correct {
    background-color: rgba(16, 185, 129, 0.15);
    border-color: var(--accent-green);
    color: var(--accent-green);
}

.quiz-btn.incorrect {
    background-color: rgba(239, 68, 68, 0.15);
    border-color: var(--accent-red);
    color: var(--accent-red);
}

.quiz-feedback {
    display: block;
    margin-top: 0.75rem;
    font-size: 0.8rem;
    font-weight: 500;
}

/* --- Buttons --- */
.btn {
    background: none;
    border: none;
    outline: none;
    padding: 0.75rem 1.5rem;
    border-radius: 10px;
    font-weight: 600;
    font-size: 0.9rem;
    cursor: pointer;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
}

.btn-primary {
    background-color: var(--accent-blue);
    color: #ffffff;
    box-shadow: var(--glow-blue);
}

.btn-primary:hover {
    background-color: var(--accent-blue-hover);
    transform: translateY(-1px);
}

.btn-secondary {
    background-color: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    color: var(--text-primary);
}

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

.btn-success {
    background-color: var(--accent-green);
    color: #ffffff;
    box-shadow: 0 0 15px rgba(16, 185, 129, 0.35);
}

.btn-success:hover {
    background-color: #059669;
    transform: translateY(-1px);
}

.btn-danger {
    background-color: var(--accent-red);
    color: #ffffff;
}

.btn-danger:hover {
    background-color: #dc2626;
}

.btn-sm {
    padding: 0.5rem 1rem;
    font-size: 0.8rem;
}

.action-footer {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-top: 2rem;
    padding-top: 1.5rem;
    border-top: 1px solid var(--border-color);
}

/* --- Checkbox Checklist --- */
.step-check {
    margin: 1.5rem 0;
    padding: 1rem;
    background-color: var(--bg-tertiary);
    border-radius: 10px;
    border: 1px solid var(--border-color);
}

.checkbox-container {
    display: block;
    position: relative;
    padding-left: 35px;
    cursor: pointer;
    font-size: 0.9rem;
    font-weight: 500;
    line-height: 1.4;
    user-select: none;
    color: var(--text-primary);
}

.checkbox-container input {
    position: absolute;
    opacity: 0;
    cursor: pointer;
    height: 0;
    width: 0;
}

.checkmark {
    position: absolute;
    top: 0;
    left: 0;
    height: 22px;
    width: 22px;
    background-color: var(--bg-primary);
    border: 1px solid var(--border-color);
    border-radius: 6px;
    transition: all 0.2s ease;
}

.checkbox-container:hover input ~ .checkmark {
    border-color: var(--accent-blue);
}

.checkbox-container input:checked ~ .checkmark {
    background-color: var(--accent-green);
    border-color: var(--accent-green);
}

.checkmark:after {
    content: "";
    position: absolute;
    display: none;
}

.checkbox-container input:checked ~ .checkmark:after {
    display: block;
}

.checkbox-container .checkmark:after {
    left: 7px;
    top: 3px;
    width: 6px;
    height: 11px;
    border: solid white;
    border-width: 0 2.5px 2.5px 0;
    transform: rotate(45deg);
}

/* --- Split Panel Layout --- */
.split-instruction {
    display: grid;
    grid-template-columns: 1.1fr 0.9fr;
    gap: 2.5rem;
}

.instruction-left, .instruction-right {
    min-width: 0; /* Prevents long code boxes or list lines from forcing columns to stretch */
}

@media (max-width: 992px) {
    .split-instruction {
        grid-template-columns: 1fr;
    }
}

/* --- Guided flow items --- */
.steps-flow {
    display: flex;
    flex-direction: column;
    gap: 1.25rem;
    margin-bottom: 2rem;
}

.flow-step {
    display: flex;
    gap: 1.25rem;
    background-color: var(--bg-primary);
    border: 1px solid var(--border-color);
    padding: 1.25rem;
    border-radius: 12px;
}

.flow-step-badge {
    background: linear-gradient(135deg, var(--accent-blue), var(--accent-purple));
    color: #ffffff;
    width: 28px;
    height: 28px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 0.85rem;
    flex-shrink: 0;
}

.flow-step-text h5 {
    font-size: 0.95rem;
    font-weight: 600;
    margin-bottom: 0.35rem;
}

.flow-step-text p {
    font-size: 0.85rem;
    margin-bottom: 0;
    color: var(--text-secondary);
}

/* --- Deliverables Section --- */
.deliverables-alert {
    background-color: rgba(16, 185, 129, 0.03);
    border: 1px solid rgba(16, 185, 129, 0.15);
    border-radius: 12px;
    padding: 1.5rem;
    margin-bottom: 1.5rem;
}

.deliverables-alert h4 {
    color: var(--accent-green);
    margin-bottom: 1rem;
    font-weight: 700;
}

.deliverable-list {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.deliverable-list li {
    display: flex;
    align-items: flex-start;
    gap: 0.75rem;
    font-size: 0.9rem;
}

.deliverable-list li input[type="checkbox"] {
    margin-top: 0.25rem;
    accent-color: var(--accent-green);
}

.deliverable-list li .desc {
    display: block;
    font-size: 0.8rem;
    color: var(--text-secondary);
    margin-top: 0.2rem;
}

/* --- Permission Simulator Widget --- */
.sim-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1rem;
    margin-bottom: 1.25rem;
    margin-top: 1rem;
}

.sim-col {
    display: flex;
    flex-direction: column;
    gap: 0.35rem;
}

.sim-col label {
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    color: var(--text-secondary);
}

.sim-output-box {
    background-color: var(--bg-primary);
    border: 1px solid var(--border-color);
    border-radius: 10px;
    padding: 1.25rem;
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
    transition: all 0.25s ease;
}

.sim-status-label {
    font-size: 0.85rem;
    font-weight: 700;
    letter-spacing: 0.05em;
    padding: 0.25rem 0.5rem;
    border-radius: 4px;
    width: fit-content;
}

.status-granted {
    background-color: rgba(16, 185, 129, 0.15);
    color: var(--accent-green);
}

.status-denied {
    background-color: rgba(239, 68, 68, 0.15);
    color: var(--accent-red);
}

.sim-details-text {
    font-size: 0.85rem;
    color: var(--text-secondary);
    margin-bottom: 0 !important;
}

/* --- AD Tree Visualization --- */
.simulator-control-bar {
    display: flex;
    gap: 0.5rem;
    margin-bottom: 1.5rem;
    flex-wrap: wrap;
}

.ad-tree-panel {
    background-color: var(--bg-primary);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 1.5rem;
    overflow-x: auto;
    min-height: 250px;
}

.tree-node {
    margin-left: 1.5rem;
    position: relative;
    margin-top: 0.5rem;
}

.tree-node::before {
    content: '';
    position: absolute;
    top: -10px;
    left: -12px;
    border-left: 1px dashed var(--border-color);
    border-bottom: 1px dashed var(--border-color);
    width: 10px;
    height: 20px;
}

.root-node {
    margin-left: 0;
}

.root-node::before {
    display: none;
}

.node-label {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    background-color: var(--bg-secondary);
    border: 1px solid var(--border-color);
    padding: 0.4rem 0.85rem;
    border-radius: 8px;
    font-size: 0.85rem;
    transition: all 0.2s ease;
}

.node-label:hover {
    border-color: var(--accent-blue);
    background-color: var(--bg-tertiary);
}

.node-name {
    font-weight: 600;
}

.node-type {
    font-size: 0.7rem;
    color: var(--text-secondary);
    background-color: var(--bg-primary);
    padding: 0.1rem 0.35rem;
    border-radius: 4px;
    margin-left: 0.5rem;
    text-transform: uppercase;
}

.node-children {
    display: flex;
    flex-direction: column;
}

/* --- Modals / Celebration Overlay --- */
.overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    background-color: rgba(11, 15, 25, 0.85);
    backdrop-filter: blur(8px);
    z-index: 1000;
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.3s ease;
}

.overlay.active {
    opacity: 1;
    pointer-events: auto;
}

.modal-card {
    background-color: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: 20px;
    padding: 3rem;
    max-width: 500px;
    width: 90%;
    text-align: center;
    box-shadow: var(--card-shadow);
    transform: scale(0.9);
    transition: transform 0.3s cubic-bezier(0.34, 1.56, 0.64, 1);
}

.overlay.active .modal-card {
    transform: scale(1);
}

.modal-icon {
    font-size: 4rem;
    margin-bottom: 1.5rem;
}

.modal-card h2 {
    font-size: 1.8rem;
    font-weight: 700;
    margin-bottom: 0.75rem;
}

.modal-card p {
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
    line-height: 1.5;
}

/* --- Student Profile Styles --- */
.student-profile-box {
    background: rgba(255, 255, 255, 0.03);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 1.15rem;
    margin-bottom: 1.5rem;
    display: flex;
    flex-direction: column;
    gap: 0.85rem;
}

.student-profile-box h3 {
    font-size: 0.85rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--accent-blue);
    font-weight: 700;
}

.profile-input-group {
    display: flex;
    flex-direction: column;
    gap: 0.35rem;
}

.profile-input-group label {
    font-size: 0.7rem;
    font-weight: 600;
    color: var(--text-secondary);
    text-transform: uppercase;
}

.profile-input-group input {
    background-color: var(--bg-primary);
    border: 1px solid var(--border-color);
    border-radius: 6px;
    padding: 0.45rem 0.65rem;
    color: var(--text-primary);
    font-size: 0.8rem;
    outline: none;
    transition: border-color 0.2s ease;
}

.profile-input-group input:focus {
    border-color: var(--accent-blue);
}

.profile-output-domain {
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 0.8rem;
    padding-top: 0.65rem;
    border-top: 1px dashed var(--border-color);
}

.profile-output-domain span {
    color: var(--text-secondary);
}

.profile-output-domain strong {
    color: var(--accent-purple);
    font-family: var(--font-mono);
}

/* --- Video Concepts Explainers --- */
.video-concepts-box {
    display: flex;
    flex-direction: column;
    gap: 1.25rem;
    margin: 1.5rem 0;
}

.concept-item {
    background-color: var(--bg-primary);
    border: 1px solid var(--border-color);
    border-radius: 10px;
    padding: 1.25rem;
}

.concept-badge {
    display: inline-block;
    background: rgba(139, 92, 246, 0.15);
    color: var(--accent-purple);
    font-size: 0.75rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    padding: 0.25rem 0.5rem;
    border-radius: 4px;
    margin-bottom: 0.75rem;
}

.concept-item p {
    font-size: 0.85rem;
    color: var(--text-secondary);
    margin-bottom: 0;
    line-height: 1.6;
}

/* --- Shares Definitions Grid --- */
.shares-definition-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1.25rem;
    margin-bottom: 1.5rem;
}

@media (max-width: 768px) {
    .shares-definition-grid {
        grid-template-columns: 1fr;
    }
}

.share-def-card {
    background-color: var(--bg-primary);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 1.25rem;
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.share-def-card h3 {
    font-size: 0.95rem;
    font-weight: 700;
    color: var(--text-primary);
}

.share-def-card p {
    font-size: 0.8rem;
    color: var(--text-secondary);
    margin-bottom: 0 !important;
}

/* --- DNS Simulation Widget --- */
.dns-simulation-widget {
    background-color: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 1.5rem;
    margin-bottom: 1.5rem;
}

.dns-simulation-widget h4 {
    font-size: 0.95rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
}

.dns-simulation-widget p {
    font-size: 0.85rem;
    color: var(--text-secondary);
    margin-bottom: 1rem;
}

.dns-control-row {
    display: flex;
    gap: 0.75rem;
    margin-bottom: 1rem;
}

.dns-toggle-btn {
    background-color: var(--bg-primary);
    border: 1px solid var(--border-color);
    color: var(--text-secondary);
    padding: 0.5rem 1rem;
    border-radius: 8px;
    font-size: 0.8rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s ease;
}

.dns-toggle-btn.active {
    background-color: var(--accent-blue);
    border-color: var(--accent-blue);
    color: #ffffff;
    box-shadow: var(--glow-blue);
}

.dns-result-box {
    background-color: var(--bg-primary);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 1rem;
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.dns-status-badge {
    font-size: 0.75rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    padding: 0.2rem 0.5rem;
    border-radius: 4px;
    width: fit-content;
}