/* Enhanced styles for SRH HQRE website */

/* Base styles with enhanced color palette */
:root {
    /* Primary quantum-inspired color palette */
    --primary-color: #5e35b1;       /* Deep purple - represents quantum core */
    --primary-light: #9162e4;       /* Lighter purple for highlights */
    --primary-dark: #280680;        /* Darker purple for depth */
    
    /* Secondary colors */
    --secondary-color: #00b0ff;     /* Bright blue - represents neural interface */
    --secondary-light: #69e2ff;     /* Lighter blue for highlights */
    --secondary-dark: #0081cb;      /* Darker blue for depth */
    
    /* Accent colors */
    --accent-color: #00e5ff;        /* Cyan - represents holographic elements */
    --accent-secondary: #ff4081;    /* Pink - represents reality interface */
    --accent-tertiary: #76ff03;     /* Lime - represents hypercube framework */
    
    /* Text colors */
    --text-color: #212121;          /* Near black for main text */
    --text-secondary: #616161;      /* Dark gray for secondary text */
    --light-text: #f5f5f5;          /* Off-white for text on dark backgrounds */
    
    /* Background colors */
    --bg-color: #ffffff;            /* White for main background */
    --bg-light: #f5f7fa;            /* Light gray for secondary backgrounds */
    --bg-dark: #121212;             /* Near black for dark mode */
    
    /* Border colors */
    --border-color: #e1e4e8;        /* Light gray for borders */
    --border-dark: #424242;         /* Dark gray for borders in dark mode */
    
    /* Shadow colors */
    --shadow-light: rgba(0, 0, 0, 0.1);
    --shadow-medium: rgba(0, 0, 0, 0.15);
    --shadow-dark: rgba(0, 0, 0, 0.3);
    
    /* Animation speeds */
    --transition-slow: 0.5s ease;
    --transition-medium: 0.3s ease;
    --transition-fast: 0.15s ease;
    
    /* Spacing variables */
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;
    --spacing-xxl: 5rem;
    
    /* Border radius */
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 16px;
    --radius-circle: 50%;
}

/* Dark mode variables */
.dark-mode {
    --primary-color: #7c4dff;
    --primary-light: #b47cff;
    --primary-dark: #3f1dcb;
    
    --secondary-color: #00b0ff;
    --secondary-light: #69e2ff;
    --secondary-dark: #0081cb;
    
    --text-color: #e0e0e0;
    --text-secondary: #9e9e9e;
    --light-text: #f5f5f5;
    
    --bg-color: #121212;
    --bg-light: #1e1e1e;
    
    --border-color: #424242;
    
    --shadow-light: rgba(0, 0, 0, 0.5);
    --shadow-medium: rgba(0, 0, 0, 0.7);
    --shadow-dark: rgba(0, 0, 0, 0.9);
}

/* Base styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
    scroll-padding-top: 80px; /* Account for fixed header */
}

body {
    font-family: 'Roboto', 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--bg-color);
    transition: background-color var(--transition-medium), color var(--transition-medium);
}

.container {
    width: 90%;
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 15px;
}

/* Typography with enhanced styling */
h1, h2, h3, h4, h5, h6 {
    margin-bottom: var(--spacing-md);
    line-height: 1.3;
    font-weight: 600;
    letter-spacing: -0.02em;
}

h1 {
    font-size: 3rem;
    font-weight: 700;
}

h2 {
    font-size: 2.5rem;
    position: relative;
}

h3 {
    font-size: 1.8rem;
    color: var(--primary-color);
}

h4 {
    font-size: 1.4rem;
    color: var(--secondary-color);
}

p {
    margin-bottom: var(--spacing-lg);
    font-size: 1.05rem;
}

a {
    color: var(--primary-color);
    text-decoration: none;
    transition: color var(--transition-medium), transform var(--transition-medium);
    position: relative;
}

a:hover {
    color: var(--accent-color);
}

a.text-link::after {
    content: '';
    position: absolute;
    bottom: -2px;
    left: 0;
    width: 0;
    height: 2px;
    background-color: var(--accent-color);
    transition: width var(--transition-medium);
}

a.text-link:hover::after {
    width: 100%;
}

ul {
    list-style: none;
}

/* Enhanced Header */
header {
    background-color: var(--primary-color);
    background-image: linear-gradient(135deg, var(--primary-color), var(--primary-dark));
    color: var(--light-text);
    padding: var(--spacing-md) 0;
    position: sticky;
    top: 0;
    z-index: 1000;
    box-shadow: 0 2px 10px var(--shadow-medium);
    transition: background-color var(--transition-medium), box-shadow var(--transition-medium);
}

header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    display: flex;
    align-items: center;
}

.logo-icon {
    width: 40px;
    height: 40px;
    margin-right: var(--spacing-sm);
    background: var(--accent-color);
    border-radius: var(--radius-circle);
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 0 15px var(--accent-color);
    position: relative;
    overflow: hidden;
}

.logo-icon::before {
    content: '';
    position: absolute;
    width: 100%;
    height: 100%;
    background: linear-gradient(135deg, transparent 25%, rgba(255, 255, 255, 0.2) 50%, transparent 75%);
    animation: shimmer 2s infinite;
}

@keyframes shimmer {
    0% { transform: translateX(-100%); }
    100% { transform: translateX(100%); }
}

.logo h1 {
    font-size: 1.8rem;
    margin-bottom: 0;
    font-weight: 700;
    letter-spacing: 1px;
}

.logo span {
    font-weight: 300;
}

nav ul {
    display: flex;
    flex-wrap: wrap;
}

nav ul li {
    margin-left: var(--spacing-lg);
}

nav ul li a {
    color: var(--light-text);
    font-weight: 500;
    padding: var(--spacing-sm) 0;
    position: relative;
    opacity: 0.9;
    transition: opacity var(--transition-medium);
}

nav ul li a:hover {
    opacity: 1;
    color: var(--light-text);
}

nav ul li a::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background-color: var(--accent-color);
    transition: width var(--transition-medium);
}

nav ul li a:hover::after {
    width: 100%;
}

/* Mobile menu toggle */
.menu-toggle {
    display: none;
    flex-direction: column;
    justify-content: space-between;
    width: 30px;
    height: 21px;
    cursor: pointer;
}

.menu-toggle span {
    display: block;
    height: 3px;
    width: 100%;
    background-color: var(--light-text);
    border-radius: 3px;
    transition: all var(--transition-medium);
}

/* Enhanced Hero section with particle effect */
.hero {
    background: linear-gradient(135deg, var(--primary-dark), var(--primary-color), var(--secondary-color));
    color: var(--light-text);
    padding: var(--spacing-xxl) 0;
    text-align: center;
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-image: url('../images/quantum-grid.svg');
    background-size: cover;
    opacity: 0.1;
    z-index: 1;
}

.hero-content {
    position: relative;
    z-index: 2;
}

.hero h1 {
    font-size: 4rem;
    margin-bottom: var(--spacing-sm);
    background: linear-gradient(to right, var(--accent-color), var(--secondary-light));
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
    text-shadow: 0 5px 15px var(--shadow-dark);
    animation: glow 3s infinite alternate;
}

@keyframes glow {
    0% { text-shadow: 0 0 10px rgba(0, 229, 255, 0.5); }
    100% { text-shadow: 0 0 20px rgba(0, 229, 255, 0.8), 0 0 30px rgba(0, 229, 255, 0.6); }
}

.hero h2 {
    font-size: 2rem;
    font-weight: 300;
    margin-bottom: var(--spacing-lg);
    opacity: 0.9;
}

.hero p {
    font-size: 1.3rem;
    max-width: 800px;
    margin: 0 auto var(--spacing-lg);
    opacity: 0.9;
}

.hero-buttons {
    display: flex;
    justify-content: center;
    gap: var(--spacing-md);
}

#particles-js {
    position: absolute;
    width: 100%;
    height: 100%;
    top: 0;
    left: 0;
    z-index: 1;
}

/* Enhanced Sections */
section {
    padding: var(--spacing-xxl) 0;
    position: relative;
}

.bg-light {
    background-color: var(--bg-light);
}

.bg-gradient {
    background: linear-gradient(135deg, var(--bg-light), var(--bg-color));
}

.section-title {
    text-align: center;
    margin-bottom: var(--spacing-xl);
}

.section-title h2 {
    position: relative;
    display: inline-block;
    padding-bottom: var(--spacing-sm);
}

.section-title h2::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 80px;
    height: 3px;
    background: linear-gradient(to right, var(--primary-color), var(--accent-color));
    border-radius: var(--radius-sm);
}

.section-title p {
    color: var(--text-secondary);
    font-size: 1.2rem;
    max-width: 800px;
    margin: var(--spacing-md) auto 0;
}

/* Enhanced Cards */
.grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    gap: var(--spacing-lg);
}

.card {
    background-color: var(--bg-color);
    border-radius: var(--radius-md);
    overflow: hidden;
    box-shadow: 0 5px 15px var(--shadow-light);
    transition: transform var(--transition-medium), box-shadow var(--transition-medium);
    position: relative;
    z-index: 1;
}

.card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 5px;
    background: linear-gradient(to right, var(--primary-color), var(--accent-color));
    z-index: 2;
    transform: scaleX(0);
    transform-origin: left;
    transition: transform var(--transition-medium);
}

.card:hover {
    transform: translateY(-10px);
    box-shadow: 0 15px 30px var(--shadow-medium);
}

.card:hover::before {
    transform: scaleX(1);
}

.card-img {
    height: 200px;
    background-color: var(--primary-light);
    background-size: cover;
    background-position: center;
    position: relative;
    overflow: hidden;
}

.card-img::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(to bottom, transparent 50%, rgba(0, 0, 0, 0.5));
}

.card-content {
    padding: var(--spacing-lg);
}

.card-content h3 {
    margin-bottom: var(--spacing-md);
    position: relative;
    display: inline-block;
}

.card-content p {
    margin-bottom: var(--spacing-md);
    color: var(--text-secondary);
}

.card-content ul {
    list-style: disc;
    padding-left: var(--spacing-lg);
    margin-bottom: var(--spacing-md);
}

.card-content ul li {
    margin-bottom: var(--spacing-sm);
    color: var(--text-secondary);
}

/* Enhanced Buttons */
.btn {
    display: inline-block;
    background-color: var(--primary-color);
    color: var(--light-text);
    padding: 0.9rem 1.8rem;
    border-radius: var(--radius-md);
    font-weight: 500;
    transition: all var(--transition-medium);
    border: none;
    cursor: pointer;
    position: relative;
    overflow: hidden;
    z-index: 1;
    box-shadow: 0 4px 10px var(--shadow-light);
}

.btn::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(to right, var(--primary-color), var(--primary-light));
    z-index: -1;
    transition: opacity var(--transition-medium);
    opacity: 0;
}

.btn:hover {
    color: var(--light-text);
    transform: translateY(-3px);
    box-shadow: 0 6px 15px var(--shadow-medium);
}

.btn:hover::before {
    opacity: 1;
}

.btn:active {
    transform: translateY(-1px);
    box-shadow: 0 3px 8px var(--shadow-light);
}

.btn-outline {
    background-color: transparent;
    border: 2px solid var(--primary-color);
    color: var(--primary-color);
}

.btn-outline::before {
    background: var(--primary-color);
}

.btn-outline:hover {
    color: var(--light-text);
}

.btn-accent {
    background-color: var(--accent-color);
}

.btn-accent::before {
    background: linear-gradient(to right, var(--accent-color), var(--secondary-light));
}

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

.btn-secondary::before {
    background: linear-gradient(to right, var(--secondary-color), var(--secondary-light));
}

/* Enhanced Interactive diagrams */
.interactive-diagram {
    width: 100%;
    height: 500px;
    margin: var(--spacing-lg) 0;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    overflow: hidden;
    box-shadow: 0 5px 15px var(--shadow-light);
    transition: box-shadow var(--transition-medium);
    position: relative;
}

.interactive-diagram:hover {
    box-shadow: 0 10px 25px var(--shadow-medium);
}

.diagram-controls {
    display: flex;
    justify-content: center;
    gap: var(--spacing-md);
    margin-top: var(--spacing-md);
}

.diagram-tooltip {
    position: absolute;
    padding: var(--spacing-md);
    background-color: rgba(0, 0, 0, 0.85);
    color: white;
    border-radius: var(--radius-sm);
    pointer-events: none;
    font-size: 14px;
    max-width: 300px;
    z-index: 1000;
    box-shadow: 0 5px 15px var(--shadow-dark);
    border-left: 3px solid var(--accent-color);
}

/* Enhanced Math containers */
.math-container {
    background-color: var(--bg-light);
    padding: var(--spacing-lg);
    border-radius: var(--radius-md);
    margin: var(--spacing-lg) 0;
    box-shadow: 0 5px 15px var(--shadow-light);
    border-left: 4px solid var(--primary-color);
}

.equation {
    margin: var(--spacing-lg) 0;
    overflow-x: auto;
    padding: var(--spacing-md);
    background-color: var(--bg-color);
    border-radius: var(--radius-sm);
    box-shadow: inset 0 2px 5px var(--shadow-light);
}

#equation-explorer {
    display: grid;
    grid-template-columns: 1fr 2fr;
    grid-template-rows: auto 1fr;
    gap: var(--spacing-md);
    height: 500px;
    border-radius: var(--radius-md);
    overflow: hidden;
    box-shadow: 0 5px 15px var(--shadow-light);
}

.equation-list {
    grid-column: 1;
    grid-row: 1 / span 2;
    overflow-y: auto;
    border-right: 1px solid var(--border-color);
    padding: var(--spacing-md);
    background-color: var(--bg-light);
}

.equation-item {
    padding: var(--spacing-md);
    cursor: pointer;
    border-radius: var(--radius-sm);
    transition: background-color var(--transition-medium);
    margin-bottom: var(--spacing-sm);
}

.equation-item:hover {
    background-color: rgba(106, 90, 205, 0.1);
}

.equation-item.active {
    background-color: rgba(106, 90, 205, 0.2);
    font-weight: 500;
    border-left: 3px solid var(--primary-color);
}

.equation-display {
    grid-column: 2;
    grid-row: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: var(--spacing-md);
    background-color: white;
    border-radius: var(--radius-sm);
    box-shadow: 0 2px 5px var(--shadow-light);
}

.equation-explanation {
    grid-column: 2;
    grid-row: 2;
    padding: var(--spacing-md);
    background-color: white;
    border-radius: var(--radius-sm);
    box-shadow: 0 2px 5px var(--shadow-light);
    overflow-y: auto;
}

/* Enhanced 3D Models */
.model-container {
    width: 100%;
    height: 500px;
    margin: var(--spacing-lg) 0;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    overflow: hidden;
    position: relative;
    box-shadow: 0 5px 15px var(--shadow-light);
    transition: box-shadow var(--transition-medium);
}

.model-container:hover {
    box-shadow: 0 10px 25px var(--shadow-medium);
}

.model-controls {
    display: flex;
    justify-content: center;
    gap: var(--spacing-md);
    margin-top: var(--spacing-md);
}

.model-info-panel {
    position: absolute;
    bottom: var(--spacing-md);
    right: var(--spacing-md);
    background-color: rgba(0, 0, 0, 0.8);
    color: white;
    padding: var(--spacing-md);
    border-radius: var(--radius-sm);
    max-width: 350px;
    z-index: 10;
    box-shadow: 0 5px 15px var(--shadow-dark);
    border-left: 3px solid var(--accent-color);
    backdrop-filter: blur(5px);
}

.model-info-panel h3 {
    color: var(--accent-color);
    margin-bottom: var(--spacing-sm);
}

.model-info-panel p {
    margin-bottom: var(--spacing-sm);
    font-size: 0.9rem;
}

.model-info-panel ul {
    list-style: none;
    padding-left: 0;
}

.model-info-panel ul li {
    margin-bottom: var(--spacing-xs);
    font-size: 0.85rem;
    display: flex;
    align-items: center;
}

.model-info-panel ul li::before {
    content: '•';
    color: var(--accent-color);
    font-weight: bold;
    display: inline-block;
    width: 1em;
    margin-right: 0.5em;
}

/* Enhanced Simulation */
.simulation-container {
    width: 100%;
    margin: var(--spacing-lg) 0;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    overflow: hidden;
    padding: var(--spacing-lg);
    background-color: white;
    box-shadow: 0 5px 15px var(--shadow-light);
}

.simulation-controls {
    margin-bottom: var(--spacing-lg);
    background-color: var(--bg-light);
    padding: var(--spacing-md);
    border-radius: var(--radius-sm);
}

.control-group {
    margin-bottom: var(--spacing-md);
}

.control-group label {
    display: block;
    margin-bottom: var(--spacing-sm);
    font-weight: 500;
    color: var(--primary-color);
}

.value-display {
    margin-left: var(--spacing-md);
    font-weight: 500;
    min-width: 30px;
    text-align: right;
    color: var(--secondary-color);
}

.simulation-status {
    margin-top: var(--spacing-md);
    padding: var(--spacing-md);
    background-color: var(--bg-light);
    border-radius: var(--radius-sm);
    font-weight: 500;
    color: var(--primary-color);
    border-left: 3px solid var(--accent-color);
}

.simulation-explanation {
    margin-top: var(--spacing-lg);
    padding: var(--spacing-md);
    background-color: var(--bg-light);
    border-radius: var(--radius-sm);
}

/* Enhanced Tabs */
.tabs {
    margin: var(--spacing-lg) 0;
}

.tab-buttons {
    display: flex;
    border-bottom: 1px solid var(--border-color);
    margin-bottom: var(--spacing-md);
}

.tab-btn {
    padding: var(--spacing-md) var(--spacing-lg);
    background: none;
    border: none;
    border-bottom: 3px solid transparent;
    cursor: pointer;
    font-weight: 500;
    color: var(--text-secondary);
    transition: all var(--transition-medium);
}

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

.tab-btn.active {
    color: var(--primary-color);
    border-bottom-color: var(--primary-color);
}

.tab-content {
    display: none;
    padding: var(--spacing-md);
    background-color: var(--bg-light);
    border-radius: var(--radius-sm);
    animation: fadeIn 0.5s ease;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

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

/* Component details sections */
.component-details {
    display: none;
    margin-top: var(--spacing-xl);
    padding: var(--spacing-lg);
    background-color: var(--bg-light);
    border-radius: var(--radius-md);
    box-shadow: 0 5px 15px var(--shadow-light);
    animation: slideIn 0.5s ease;
}

@keyframes slideIn {
    from { opacity: 0; transform: translateY(30px); }
    to { opacity: 1; transform: translateY(0); }
}

.component-info {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-lg);
}

.specs-list {
    list-style: none;
    padding-left: 0;
}

.specs-list li {
    margin-bottom: var(--spacing-sm);
    padding-left: var(--spacing-md);
    position: relative;
}

.specs-list li::before {
    content: '';
    position: absolute;
    left: 0;
    top: 10px;
    width: 6px;
    height: 6px;
    border-radius: 50%;
    background-color: var(--primary-color);
}

/* Research tracks */
.research-tracks {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-lg);
}

.track {
    padding: var(--spacing-lg);
    background-color: var(--bg-color);
    border-radius: var(--radius-md);
    box-shadow: 0 5px 15px var(--shadow-light);
    transition: transform var(--transition-medium), box-shadow var(--transition-medium);
    position: relative;
    overflow: hidden;
}

.track::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 5px;
    background: linear-gradient(to right, var(--primary-color), var(--accent-color));
}

.track:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 25px var(--shadow-medium);
}

.track h3 {
    margin-bottom: var(--spacing-md);
}

.track ul {
    list-style: disc;
    padding-left: var(--spacing-lg);
    margin-bottom: var(--spacing-md);
}

.track ul li {
    margin-bottom: var(--spacing-sm);
}

/* Contact section */
.contact-info {
    max-width: 800px;
    margin: 0 auto;
}

.contact-details {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--spacing-lg);
    margin-top: var(--spacing-lg);
}

.contact-item {
    padding: var(--spacing-lg);
    background-color: var(--bg-color);
    border-radius: var(--radius-md);
    box-shadow: 0 5px 15px var(--shadow-light);
    transition: transform var(--transition-medium), box-shadow var(--transition-medium);
    text-align: center;
}

.contact-item:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 25px var(--shadow-medium);
}

.contact-item h3 {
    margin-bottom: var(--spacing-sm);
}

.contact-item p {
    margin-bottom: var(--spacing-sm);
}

/* Enhanced Footer */
footer {
    background-color: var(--primary-dark);
    color: var(--light-text);
    padding: var(--spacing-xl) 0 var(--spacing-lg);
    position: relative;
    overflow: hidden;
}

footer::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-image: url('../images/quantum-grid.svg');
    background-size: cover;
    opacity: 0.05;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-lg);
    position: relative;
}

.footer-column h3 {
    color: var(--accent-color);
    margin-bottom: var(--spacing-md);
    position: relative;
    display: inline-block;
}

.footer-column h3::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 40px;
    height: 2px;
    background-color: var(--accent-color);
}

.footer-column p {
    margin-bottom: var(--spacing-md);
    opacity: 0.8;
}

.footer-column ul li {
    margin-bottom: var(--spacing-sm);
}

.footer-column ul li a {
    color: var(--light-text);
    opacity: 0.8;
    transition: opacity var(--transition-medium);
}

.footer-column ul li a:hover {
    opacity: 1;
    color: var(--accent-color);
}

.copyright {
    text-align: center;
    padding-top: var(--spacing-md);
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    position: relative;
}

.copyright p {
    margin-bottom: 0;
    opacity: 0.7;
    font-size: 0.9rem;
}

/* New Feature: Dark Mode Toggle */
.theme-toggle {
    position: fixed;
    bottom: 20px;
    right: 20px;
    width: 50px;
    height: 50px;
    border-radius: 50%;
    background-color: var(--primary-color);
    color: var(--light-text);
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    z-index: 1000;
    box-shadow: 0 5px 15px var(--shadow-medium);
    transition: background-color var(--transition-medium), transform var(--transition-medium);
}

.theme-toggle:hover {
    transform: scale(1.1);
}

.theme-toggle i {
    font-size: 1.5rem;
}

/* New Feature: Search Bar */
.search-container {
    position: relative;
    margin-left: var(--spacing-lg);
}

.search-input {
    padding: var(--spacing-sm) var(--spacing-md);
    padding-right: 40px;
    border: none;
    border-radius: var(--radius-md);
    background-color: rgba(255, 255, 255, 0.1);
    color: var(--light-text);
    width: 200px;
    transition: width var(--transition-medium), background-color var(--transition-medium);
}

.search-input:focus {
    outline: none;
    width: 250px;
    background-color: rgba(255, 255, 255, 0.2);
}

.search-input::placeholder {
    color: rgba(255, 255, 255, 0.7);
}

.search-button {
    position: absolute;
    right: 10px;
    top: 50%;
    transform: translateY(-50%);
    background: none;
    border: none;
    color: var(--light-text);
    cursor: pointer;
}

/* New Feature: Progress Indicator */
.progress-container {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 5px;
    background: transparent;
    z-index: 1001;
}

.progress-bar {
    height: 100%;
    background: linear-gradient(to right, var(--accent-color), var(--primary-light));
    width: 0%;
    transition: width 0.1s ease;
}

/* New Feature: Glossary Terms */
.glossary-term {
    text-decoration: underline dotted var(--primary-color);
    cursor: help;
    position: relative;
}

.glossary-tooltip {
    position: absolute;
    bottom: 100%;
    left: 50%;
    transform: translateX(-50%);
    padding: var(--spacing-md);
    background-color: var(--bg-color);
    color: var(--text-color);
    border-radius: var(--radius-sm);
    box-shadow: 0 5px 15px var(--shadow-medium);
    width: 300px;
    opacity: 0;
    visibility: hidden;
    transition: opacity var(--transition-medium), visibility var(--transition-medium);
    z-index: 1000;
    pointer-events: none;
    border-left: 3px solid var(--primary-color);
}

.glossary-term:hover .glossary-tooltip {
    opacity: 1;
    visibility: visible;
}

/* New Feature: Timeline */
.timeline {
    position: relative;
    max-width: 1200px;
    margin: 0 auto;
    padding: var(--spacing-lg) 0;
}

.timeline::after {
    content: '';
    position: absolute;
    width: 6px;
    background-color: var(--primary-light);
    top: 0;
    bottom: 0;
    left: 50%;
    margin-left: -3px;
    border-radius: var(--radius-sm);
}

.timeline-item {
    padding: var(--spacing-md) 40px;
    position: relative;
    width: 50%;
    box-sizing: border-box;
}

.timeline-item::after {
    content: '';
    position: absolute;
    width: 20px;
    height: 20px;
    background-color: var(--accent-color);
    border: 4px solid var(--primary-color);
    top: 15px;
    border-radius: 50%;
    z-index: 1;
    box-shadow: 0 0 10px var(--accent-color);
}

.timeline-left {
    left: 0;
}

.timeline-right {
    left: 50%;
}

.timeline-left::after {
    right: -10px;
}

.timeline-right::after {
    left: -10px;
}

.timeline-content {
    padding: var(--spacing-md);
    background-color: var(--bg-color);
    border-radius: var(--radius-md);
    box-shadow: 0 5px 15px var(--shadow-light);
    position: relative;
}

.timeline-content::after {
    content: '';
    position: absolute;
    border-width: 10px;
    border-style: solid;
    top: 15px;
}

.timeline-left .timeline-content::after {
    border-color: transparent transparent transparent var(--bg-color);
    right: -20px;
}

.timeline-right .timeline-content::after {
    border-color: transparent var(--bg-color) transparent transparent;
    left: -20px;
}

.timeline-date {
    color: var(--primary-color);
    font-weight: 600;
}

/* New Feature: Comparison Tool */
.comparison-table {
    width: 100%;
    border-collapse: collapse;
    margin: var(--spacing-lg) 0;
    box-shadow: 0 5px 15px var(--shadow-light);
    border-radius: var(--radius-md);
    overflow: hidden;
}

.comparison-table th,
.comparison-table td {
    padding: var(--spacing-md);
    text-align: left;
    border-bottom: 1px solid var(--border-color);
}

.comparison-table th {
    background-color: var(--primary-color);
    color: var(--light-text);
    font-weight: 500;
}

.comparison-table tr:nth-child(even) {
    background-color: var(--bg-light);
}

.comparison-table tr:hover {
    background-color: rgba(106, 90, 205, 0.1);
}

.comparison-feature {
    font-weight: 500;
}

.comparison-value {
    text-align: center;
}

.comparison-highlight {
    background-color: rgba(0, 229, 255, 0.1);
    font-weight: 600;
    color: var(--primary-color);
}

/* Responsive Design Enhancements */
@media (max-width: 1200px) {
    .container {
        width: 95%;
    }
    
    .hero h1 {
        font-size: 3.5rem;
    }
    
    .hero h2 {
        font-size: 1.8rem;
    }
}

@media (max-width: 992px) {
    .hero h1 {
        font-size: 3rem;
    }
    
    .hero h2 {
        font-size: 1.6rem;
    }
    
    .research-tracks {
        grid-template-columns: 1fr;
    }
    
    .component-info {
        grid-template-columns: 1fr;
    }
    
    .timeline::after {
        left: 31px;
    }
    
    .timeline-item {
        width: 100%;
        padding-left: 70px;
        padding-right: 25px;
    }
    
    .timeline-right {
        left: 0;
    }
    
    .timeline-left::after,
    .timeline-right::after {
        left: 21px;
    }
    
    .timeline-left .timeline-content::after,
    .timeline-right .timeline-content::after {
        border-color: transparent var(--bg-color) transparent transparent;
        left: -20px;
    }
}

@media (max-width: 768px) {
    .hero h1 {
        font-size: 2.5rem;
    }
    
    .hero h2 {
        font-size: 1.4rem;
    }
    
    .hero p {
        font-size: 1.1rem;
    }
    
    .hero-buttons {
        flex-direction: column;
        align-items: center;
        gap: var(--spacing-sm);
    }
    
    .hero-buttons .btn {
        width: 100%;
        max-width: 300px;
        text-align: center;
    }
    
    nav ul {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        width: 100%;
        background-color: var(--primary-dark);
        flex-direction: column;
        padding: var(--spacing-md) 0;
        box-shadow: 0 5px 15px var(--shadow-medium);
    }
    
    nav ul.active {
        display: flex;
    }
    
    nav ul li {
        margin: 0;
        text-align: center;
    }
    
    nav ul li a {
        display: block;
        padding: var(--spacing-md);
    }
    
    .menu-toggle {
        display: flex;
    }
    
    .search-container {
        margin: var(--spacing-md) 0 0;
        width: 100%;
    }
    
    .search-input {
        width: 100%;
    }
    
    .search-input:focus {
        width: 100%;
    }
    
    #equation-explorer {
        grid-template-columns: 1fr;
        grid-template-rows: auto auto 1fr;
    }
    
    .equation-list {
        grid-column: 1;
        grid-row: 1;
        border-right: none;
        border-bottom: 1px solid var(--border-color);
        max-height: 150px;
    }
    
    .equation-display {
        grid-column: 1;
        grid-row: 2;
    }
    
    .equation-explanation {
        grid-column: 1;
        grid-row: 3;
    }
}

@media (max-width: 576px) {
    h1 {
        font-size: 2.2rem;
    }
    
    h2 {
        font-size: 1.8rem;
    }
    
    h3 {
        font-size: 1.5rem;
    }
    
    .hero h1 {
        font-size: 2.2rem;
    }
    
    .hero h2 {
        font-size: 1.3rem;
    }
    
    .section-title h2 {
        font-size: 1.8rem;
    }
    
    .section-title p {
        font-size: 1.1rem;
    }
    
    .card-content {
        padding: var(--spacing-md);
    }
    
    .footer-content {
        grid-template-columns: 1fr;
    }
}

/* Animation Classes */
.fade-in {
    animation: fadeIn 1s ease;
}

.slide-in-left {
    animation: slideInLeft 1s ease;
}

.slide-in-right {
    animation: slideInRight 1s ease;
}

.slide-in-up {
    animation: slideInUp 1s ease;
}

.slide-in-down {
    animation: slideInDown 1s ease;
}

@keyframes slideInLeft {
    from { opacity: 0; transform: translateX(-50px); }
    to { opacity: 1; transform: translateX(0); }
}

@keyframes slideInRight {
    from { opacity: 0; transform: translateX(50px); }
    to { opacity: 1; transform: translateX(0); }
}

@keyframes slideInUp {
    from { opacity: 0; transform: translateY(50px); }
    to { opacity: 1; transform: translateY(0); }
}

@keyframes slideInDown {
    from { opacity: 0; transform: translateY(-50px); }
    to { opacity: 1; transform: translateY(0); }
}

/* Utility Classes */
.text-center { text-align: center; }
.text-left { text-align: left; }
.text-right { text-align: right; }

.mt-1 { margin-top: var(--spacing-sm); }
.mt-2 { margin-top: var(--spacing-md); }
.mt-3 { margin-top: var(--spacing-lg); }
.mt-4 { margin-top: var(--spacing-xl); }
.mt-5 { margin-top: var(--spacing-xxl); }

.mb-1 { margin-bottom: var(--spacing-sm); }
.mb-2 { margin-bottom: var(--spacing-md); }
.mb-3 { margin-bottom: var(--spacing-lg); }
.mb-4 { margin-bottom: var(--spacing-xl); }
.mb-5 { margin-bottom: var(--spacing-xxl); }

.p-1 { padding: var(--spacing-sm); }
.p-2 { padding: var(--spacing-md); }
.p-3 { padding: var(--spacing-lg); }
.p-4 { padding: var(--spacing-xl); }
.p-5 { padding: var(--spacing-xxl); }

.d-flex { display: flex; }
.flex-column { flex-direction: column; }
.justify-center { justify-content: center; }
.align-center { align-items: center; }
.flex-wrap { flex-wrap: wrap; }

.w-100 { width: 100%; }
.h-100 { height: 100%; }

.position-relative { position: relative; }
.position-absolute { position: absolute; }

.rounded { border-radius: var(--radius-md); }
.shadow { box-shadow: 0 5px 15px var(--shadow-light); }
.shadow-lg { box-shadow: 0 10px 25px var(--shadow-medium); }

.bg-primary { background-color: var(--primary-color); color: var(--light-text); }
.bg-secondary { background-color: var(--secondary-color); color: var(--light-text); }
.bg-accent { background-color: var(--accent-color); color: var(--light-text); }
.bg-white { background-color: var(--bg-color); }
.bg-light { background-color: var(--bg-light); }

.text-primary { color: var(--primary-color); }
.text-secondary { color: var(--secondary-color); }
.text-accent { color: var(--accent-color); }
.text-light { color: var(--light-text); }
.text-dark { color: var(--text-color); }
.text-muted { color: var(--text-secondary); }

.border { border: 1px solid var(--border-color); }
.border-primary { border-color: var(--primary-color); }
.border-secondary { border-color: var(--secondary-color); }
.border-accent { border-color: var(--accent-color); }

.overflow-hidden { overflow: hidden; }
.overflow-auto { overflow: auto; }

.transition { transition: all var(--transition-medium); }