/* OCU Brand Color Variables */
:root {
    /* Primary Colors */
    --ocu-black: #000000;
    --ocu-true-blue: #00669b;
    --ocu-white: #ffffff;

    /* Secondary Colors */
    --ocu-dark-blue: #043d5d;
    --ocu-cyan: #009edb;
    --ocu-light-blue: #9ddcf9;

    /* Accent Colors */
    --ocu-green: #70bf54;
    --ocu-light-green: #afd46c;
    --ocu-yellow: #ffc222;
    --ocu-gold: #ffc222;
    --ocu-sky: #9ddcf9;

    /* Spacing Variables */
    --spacing-xs: 8px;
    --spacing-sm: 16px;
    --spacing-md: 24px;
    --spacing-lg: 40px;
    --spacing-xl: 60px;

    /* Typography Variables */
    --font-size-xs: 0.9em;
    --font-size-sm: 1em;
    --font-size-md: 1.2em;
    --font-size-lg: 1.5em;
    --font-size-xl: 2em;
    --font-size-xxl: 2.8em;

    /* Code Block Variables */
    --code-font-size: 1.1em;
    --code-line-height: 1.6;
    --code-padding: 12px;
    
    /* Semantic colors for light mode (default) */
    --bg-primary: #ffffff;
    --bg-secondary: #f8f9fa;
    --bg-accent: #e8f4f9;
    --text-primary: #000000;
    --text-secondary: #043d5d;
    --text-muted: #666666;
    --border-color: #009edb;
    --shadow-color: rgba(0, 102, 155, 0.15);
    --code-bg: #043d5d;
    --code-text: #ffffff;
    --success-bg: #e8f7e3;
    --success-border: #70bf54;
    --warning-bg: #fff8e5;
    --warning-border: #ffc222;
    --gradient-start: #00669b;
    --gradient-end: #009edb;
    --slide-bg: #ffffff;
    --slide-bg-rgb: 255, 255, 255; /* RGB values for transparency */
    --nav-bg: #00669b;
    --nav-text: #ffffff;
    --button-hover: #043d5d;
}

/* Dark Mode Variables */
[data-theme="dark"] {
    --bg-primary: #000000;
    --bg-secondary: #1a1a1a;
    --bg-accent: #043d5d;
    --text-primary: #ffffff;
    --text-secondary: #9ddcf9;
    --text-muted: #aaaaaa;
    --border-color: #009edb;
    --shadow-color: rgba(0, 158, 219, 0.3);
    --code-bg: #1a1a1a;
    --code-text: #9ddcf9;
    --success-bg: rgba(112, 191, 84, 0.1);
    --success-border: #afd46c;
    --warning-bg: rgba(255, 194, 34, 0.1);
    --warning-border: #ffc222;
    --gradient-start: #043d5d;
    --gradient-end: #00669b;
    --slide-bg: #1a1a1a;
    --slide-bg-rgb: 26, 26, 26; /* RGB values for transparency */
    --nav-bg: #043d5d;
    --nav-text: #ffffff;
    --button-hover: #009edb;
}

/* Reset and Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: linear-gradient(135deg, var(--gradient-start) 0%, var(--gradient-end) 100%);
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    transition: background 0.3s ease;
}

.controls{
    padding: 20px;
}

/* Top Controls Container - Merged Theme Toggle + Title/Home */
.top-controls {
    position: fixed;
    top: 20px;
    right: 20px;
    z-index: 1000;
    background: rgba(var(--slide-bg-rgb), 0.65);
    backdrop-filter: blur(10px);
    padding: 10px 20px;
    border-radius: 30px;
    box-shadow: 0 4px 10px var(--shadow-color);
    display: flex;
    align-items: center;
    gap: 15px;
    border: 1px solid var(--border-color);
    transition: opacity 0.3s ease, transform 0.3s ease, width 0.3s ease, height 0.3s ease;
}

.top-controls.controls-hidden {
    opacity: 0;
    transform: translateX(calc(100% - 50px));
    pointer-events: none;
}

.top-controls.controls-hidden .control-tab {
    pointer-events: all;
    opacity: 1;
}

.control-tab {
    position: absolute;
    right: 0;
    top: 50%;
    transform: translateY(-50%);
    width: 40px;
    height: 60px;
    background: rgba(var(--slide-bg-rgb), 0.8);
    backdrop-filter: blur(10px);
    border-radius: 10px 0 0 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.2em;
    cursor: pointer;
    border: 1px solid var(--border-color);
    border-right: none;
    opacity: 0;
    transition: opacity 0.3s ease, background 0.2s ease;
}

.top-controls.controls-hidden .control-tab {
    opacity: 0.7;
}

.control-tab:hover {
    background: rgba(var(--slide-bg-rgb), 0.95);
    opacity: 1 !important;
}

.lecture-info {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 1.1em;
    color: var(--text-primary);
    font-weight: 500;
}

/* Theme Toggle Switch */
.theme-toggle {
    display: flex;
    align-items: center;
    gap: 10px;
}

.theme-toggle-label {
    color: var(--text-primary);
    font-size: 0.9em;
    user-select: none;
}

.theme-switch {
    position: relative;
    width: 60px;
    height: 30px;
}

.theme-switch input {
    opacity: 0;
    width: 0;
    height: 0;
}

.theme-slider {
    position: absolute;
    cursor: pointer;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-color: var(--ocu-light-blue);
    transition: .4s;
    border-radius: 30px;
}

.theme-slider:before {
    position: absolute;
    content: "☀️";
    height: 24px;
    width: 24px;
    left: 3px;
    bottom: 3px;
    background-color: white;
    transition: .4s;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 14px;
}

input:checked + .theme-slider {
    background-color: var(--ocu-dark-blue);
}

input:checked + .theme-slider:before {
    transform: translateX(30px);
    content: "🌙";
}

/* Presentation Container */
.presentation-container {
    width: 90vw;
    height: 90vh;
    background: var(--slide-bg);
    border-radius: 20px;
    box-shadow: 0 20px 60px var(--shadow-color);
    position: relative;
    overflow: hidden;
    transition: background 0.3s ease, color 0.3s ease;
}

/* Slide Styles */
.slide {
    width: 100%;
    height: 100%;
    padding: 60px;
    padding-bottom: 120px; /* Fixed: Prevent navigation overlap */
    display: none;
    flex-direction: column;
    animation: slideIn 0.5s ease-in-out;
    overflow-y: auto;
    background: var(--slide-bg);
    color: var(--text-primary);
}

.slide.active {
    display: flex;
}

@keyframes slideIn {
    from {
        opacity: 0;
        transform: translateX(100px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

/* Home Button - styled within top-controls by presentation.js */
.home {
    background: var(--ocu-cyan);
    padding: 8px 15px;
    border-radius: 5px;
    border: none;
    transition: all 0.3s ease;
}

.home:hover {
    background: var(--ocu-true-blue);
}

.home a{
    color: white;
    text-decoration: none;
    font-weight: 500;
}

/* Typography */
h1 {
    color: var(--ocu-true-blue);
    font-size: 2.8em;
    margin-bottom: 30px;
    border-bottom: 3px solid var(--border-color);
    padding-bottom: 20px;
    transition: color 0.3s ease;
}

[data-theme="dark"] h1 {
    color: var(--ocu-cyan);
}

h2 {
    color: var(--ocu-dark-blue);
    font-size: 2.2em;
    margin-bottom: 25px;
    margin-top: 30px;
    transition: color 0.3s ease;
}

[data-theme="dark"] h2 {
    color: var(--ocu-light-blue);
}

h3 {
    color: var(--text-secondary);
    font-size: 1.6em;
    margin: 20px 0;
    transition: color 0.3s ease;
}

p, li {
    font-size: 1.2em;
    line-height: 1.7;
    color: var(--text-primary);
    margin-bottom: 15px;
    transition: color 0.3s ease;
}

ul, ol {
    margin-left: 30px;
    margin-bottom: 20px;
}

li {
    margin-bottom: 12px;
}

/* Code Examples */
.code-example {
    background: var(--code-bg);
    color: var(--code-text);
    padding: var(--code-padding);
    border-radius: 10px;
    font-family: 'Courier New', monospace;
    margin: 20px 0;
    font-size: var(--code-font-size);
    line-height: var(--code-line-height);
    border: 1px solid var(--border-color);
    box-shadow: 0 4px 6px var(--shadow-color);
    /* Fixed: Prevent internal scrolling, allow wrapping */
    overflow: visible;
    overflow-x: visible;
    white-space: pre-wrap;
    word-wrap: break-word;
    transition: all 0.3s ease;
}

.code-example br {
    line-height: 0;
    margin: 0;
}

/* Code Block Size Variants */
.code-example.code-lg {
    font-size: 1.5em;
    padding: 30px;
}

.code-example.code-md {
    font-size: 1.3em;
    padding: 25px;
}

.code-example.code-sm {
    font-size: 1em;
    padding: 15px;
}

.code-example .tag {
    color: var(--ocu-yellow);
}

.code-example .attribute {
    color: var(--ocu-light-green);
}

.code-example .value {
    color: var(--ocu-cyan);
}

[data-theme="dark"] .code-example .value {
    color: var(--ocu-light-blue);
}

.code-example .content {
    color: var(--code-text);
}

.code-example .comment {
    color: var(--text-muted);
    font-style: italic;
}

.code-example .good {
    color: var(--ocu-green);
}

.code-example .bad {
    color: #ff5555;
}

/* Utility Classes */
.highlight {
    background: linear-gradient(120deg, var(--ocu-true-blue) 0%, var(--ocu-cyan) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    font-weight: bold;
}

.emoji {
    font-size: 1.3em;
    margin: 0 8px;
}

/* Box Components */
.activity-box {
    background: linear-gradient(135deg, var(--ocu-true-blue) 0%, var(--ocu-cyan) 100%);
    color: white;
    padding: 30px;
    border-radius: 15px;
    margin: 30px 0;
    box-shadow: 0 4px 10px var(--shadow-color);
}

[data-theme="dark"] .activity-box {
    background: linear-gradient(135deg, var(--ocu-dark-blue) 0%, var(--ocu-true-blue) 100%);
}

.activity-box h3 {
    color: white;
    margin-bottom: 15px;
}

.activity-box p,
.activity-box li {
    color: white;
}

.visual-example {
    background: var(--bg-accent);
    border: 2px dashed var(--border-color);
    padding: 30px;
    border-radius: 10px;
    margin: 20px 0;
    transition: all 0.3s ease;
}

.tip-box, .tip {
    background: var(--success-bg);
    border-left: 4px solid var(--success-border);
    padding: 20px;
    border-radius: 8px;
    margin: 20px 0;
    transition: all 0.3s ease;
}

.warning-box, .warning {
    background: var(--warning-bg);
    border-left: 4px solid var(--warning-border);
    padding: 20px;
    border-radius: 8px;
    margin: 20px 0;
    transition: all 0.3s ease;
}

.demo-box {
    background: var(--bg-accent);
    border: 2px dashed var(--border-color);
    padding: 30px;
    border-radius: 15px;
    margin: 25px 0;
    text-align: center;
    transition: all 0.3s ease;
}

/* Layout Utilities */
.comparison-table {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 30px;
    margin: 30px 0;
}

.comparison-card {
    background: var(--bg-secondary);
    padding: 25px;
    border-radius: 10px;
    border-top: 4px solid var(--border-color);
    box-shadow: 0 4px 6px var(--shadow-color);
    transition: all 0.3s ease;
}

.comparison-card.bad {
    background: rgba(255, 85, 85, 0.1);
    border-left: 4px solid #ff5555;
}

.comparison-card.good {
    background: var(--success-bg);
    border-left: 4px solid var(--success-border);
}

.two-column {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 40px;
    margin: 30px 0;
}

/* Navigation Controls */
.navigation {
    position: absolute;
    bottom: 30px;
    right: 30px;
    display: flex;
    gap: 20px;
    align-items: center;
    z-index: 100;
    background: rgba(var(--slide-bg-rgb), 0.65);
    backdrop-filter: blur(10px);
    padding: 15px 25px;
    border-radius: 30px;
    box-shadow: 0 4px 10px var(--shadow-color);
    transition: opacity 0.3s ease, transform 0.3s ease;
}

.navigation.controls-hidden {
    opacity: 0;
    transform: translateX(calc(100% - 50px));
    pointer-events: none;
}

.navigation.controls-hidden .nav-tab {
    pointer-events: all;
    opacity: 1;
}

.nav-tab {
    position: absolute;
    right: 0;
    top: 50%;
    transform: translateY(-50%);
    width: 40px;
    height: 60px;
    background: rgba(var(--slide-bg-rgb), 0.8);
    backdrop-filter: blur(10px);
    border-radius: 10px 0 0 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.2em;
    cursor: pointer;
    border: 1px solid var(--border-color);
    border-right: none;
    opacity: 0;
    transition: opacity 0.3s ease, background 0.2s ease;
}

.navigation.controls-hidden .nav-tab {
    opacity: 0.7;
}

.nav-tab:hover {
    background: rgba(var(--slide-bg-rgb), 0.95);
    opacity: 1 !important;
}

button {
    background: var(--nav-bg);
    color: var(--nav-text);
    border: none;
    padding: 12px 24px;
    border-radius: 25px;
    font-size: 1em;
    cursor: pointer;
    transition: all 0.3s ease;
}

button:hover {
    background: var(--button-hover);
    transform: translateY(-2px);
    box-shadow: 0 5px 15px var(--shadow-color);
}

button:disabled {
    background: var(--text-muted);
    cursor: not-allowed;
    transform: none;
    opacity: 0.5;
}

.slide-counter {
    font-size: 1.1em;
    color: var(--text-primary);
    font-weight: bold;
    margin: 0 10px;
}

/* Legacy timer styles - kept for compatibility but hidden */
.timer, .timer-display {
    display: none;
}

/* Inline Code */
code {
    background: var(--bg-accent);
    padding: 2px 6px;
    border-radius: 3px;
    font-family: 'Courier New', monospace;
    color: var(--ocu-true-blue);
    transition: all 0.3s ease;
}

[data-theme="dark"] code {
    color: var(--ocu-cyan);
}

/* Special List Styles */
.icon-list {
    list-style: none;
    margin-left: 0;
}

.icon-list li::before {
    content: "→ ";
    color: var(--ocu-true-blue);
    font-weight: bold;
    margin-right: 10px;
}

[data-theme="dark"] .icon-list li::before {
    color: var(--ocu-cyan);
}

/* Scrollbar Styling */
.slide::-webkit-scrollbar {
    width: 10px;
}

.slide::-webkit-scrollbar-track {
    background: var(--bg-secondary);
    border-radius: 10px;
}

.slide::-webkit-scrollbar-thumb {
    background: var(--ocu-true-blue);
    border-radius: 10px;
}

.slide::-webkit-scrollbar-thumb:hover {
    background: var(--ocu-dark-blue);
}

[data-theme="dark"] .slide::-webkit-scrollbar-thumb {
    background: var(--ocu-cyan);
}

[data-theme="dark"] .slide::-webkit-scrollbar-thumb:hover {
    background: var(--ocu-light-blue);
}

/* Responsive Design */
@media (max-width: 768px) {
    .presentation-container {
        width: 100vw;
        height: 100vh;
        border-radius: 0;
    }
    
    .slide {
        padding: 30px;
    }
    
    h1 {
        font-size: 2em;
    }
    
    h2 {
        font-size: 1.6em;
    }
    
    .comparison-table,
    .two-column {
        grid-template-columns: 1fr;
    }
    
    .navigation {
        bottom: 20px;
        right: 20px;
        padding: 10px 15px;
    }

    button {
        padding: 10px 20px;
        font-size: 0.9em;
    }

    .top-controls {
        top: 10px;
        right: 10px;
        padding: 8px 15px;
        font-size: 0.9em;
    }

    .control-tab,
    .nav-tab {
        width: 30px;
        height: 50px;
        font-size: 1em;
    }
}

/* Smooth transitions for theme switching */
* {
    transition: background-color 0.3s ease, color 0.3s ease, border-color 0.3s ease;
}

/* ========================================
   UTILITY CLASSES
   ======================================== */

/* Spacing Utilities */
.mt-sm { margin-top: var(--spacing-sm); }
.mt-md { margin-top: var(--spacing-md); }
.mt-lg { margin-top: var(--spacing-lg); }
.mb-sm { margin-bottom: var(--spacing-sm); }
.mb-md { margin-bottom: var(--spacing-md); }
.mb-lg { margin-bottom: var(--spacing-lg); }
.m-sm { margin: var(--spacing-sm); }
.m-md { margin: var(--spacing-md); }
.m-lg { margin: var(--spacing-lg); }

.p-sm { padding: var(--spacing-sm); }
.p-md { padding: var(--spacing-md); }
.p-lg { padding: var(--spacing-lg); }

/* Typography Utilities */
.text-xs { font-size: var(--font-size-xs); }
.text-sm { font-size: var(--font-size-sm); }
.text-md { font-size: var(--font-size-md); }
.text-lg { font-size: var(--font-size-lg); }
.text-xl { font-size: var(--font-size-xl); }
.text-center { text-align: center; }
.text-left { text-align: left; }
.text-right { text-align: right; }

/* Layout Utilities */
.grid-2 {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-md);
}

.grid-3 {
    display: grid;
    grid-template-columns: 1fr 1fr 1fr;
    gap: var(--spacing-md);
}

.flex-row {
    display: flex;
    flex-direction: row;
    gap: var(--spacing-sm);
}

.flex-col {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

/* ========================================
   STANDARDIZED COMPONENTS
   ======================================== */

/* Card Variants - Unify method-card, phase-card, checklist-item, etc. */
.card {
    background: var(--bg-secondary);
    padding: 20px;
    border-radius: 10px;
    margin: 15px 0;
    transition: all 0.3s ease;
}

.card-accent {
    background: var(--bg-accent);
    padding: 15px;
    border-radius: 10px;
    margin: 10px 0;
    border-left: 4px solid var(--ocu-true-blue);
}

[data-theme="dark"] .card-accent {
    border-left-color: var(--ocu-cyan);
}

.card-gradient {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 25px;
    border-radius: 15px;
    margin: 20px 0;
    box-shadow: 0 10px 20px rgba(0,0,0,0.2);
}

.card-gradient h3,
.card-gradient p,
.card-gradient li {
    color: white;
}

/* Demo Container - Unify demo-box, visual-example, example-container */
.demo-container {
    background: var(--bg-accent);
    border: 2px dashed var(--border-color);
    padding: 30px;
    border-radius: 15px;
    margin: 25px 0;
    text-align: center;
    transition: all 0.3s ease;
}

/* History Slide Components */
.history-card {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 40px;
    border-radius: 15px;
}

.history-card h1,
.history-card h2,
.history-card h3,
.history-card p,
.history-card li {
    color: white;
}

.history-content {
    background: rgba(255, 255, 255, 0.1);
    padding: 30px;
    border-radius: 15px;
    backdrop-filter: blur(10px);
}

.history-quote {
    font-style: italic;
    font-size: 1.1em;
    margin: 20px 0;
    padding-left: 20px;
    border-left: 4px solid #ffd700;
}

.history-citation {
    text-align: right;
    font-size: 0.9em;
    opacity: 0.9;
    margin-top: 10px;
}

.reflection-question {
    background: rgba(255, 255, 255, 0.2);
    padding: 20px;
    border-radius: 10px;
    margin-top: 30px;
}

.reflection-question h3 {
    color: #ffd700;
    margin-bottom: 10px;
}

/* Flex Demo Components (used in multiple lectures) */
.flex-demo {
    display: flex;
    background: var(--bg-secondary);
    padding: 20px;
    border-radius: 10px;
    margin: 20px 0;
    min-height: 100px;
    border: 2px solid var(--border-color);
    gap: 10px;
}

.flex-item {
    background: var(--ocu-true-blue);
    color: white;
    padding: 20px;
    margin: 10px;
    border-radius: 5px;
    text-align: center;
    font-weight: bold;
}

[data-theme="dark"] .flex-item {
    background: var(--ocu-dark-blue);
}

/* DOM Tree Visual (JS lectures) */
.dom-tree {
    background: var(--bg-secondary);
    padding: 25px;
    border-radius: 15px;
    margin: 20px 0;
    font-family: 'Courier New', monospace;
}

/* Checkpoint/Progress Items */
.checkpoint-item {
    background: var(--bg-accent);
    padding: 15px;
    margin: 10px 0;
    border-radius: 8px;
    border-left: 4px solid var(--ocu-true-blue);
}

[data-theme="dark"] .checkpoint-item {
    border-left-color: var(--ocu-cyan);
}

.checkpoint-list {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 15px;
    margin: 20px 0;
}