:root {
    /* Match Cogito's light mode colors */
    --primary-color: #5690af;      /* --blue */
    --secondary-color: #9271d6;    /* --purple */
    --accent-color: #d26878;       /* --accent */
    --text-primary: #41474e;       /* --text */
    --text-secondary: #646868;     /* --text-light */
    --bg-primary: #eeeeee;         /* --bg */
    --bg-secondary: #cbcdcd;       /* --bg-light */
    --border-color: #cbcdcd;       /* --grey */
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1);
    --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.1);
}

/* Dark mode - Match Cogito's dark mode colors */
.dark {
    --primary-color: #87c9e5;      /* --blue (dark) */
    --secondary-color: #b07cf3;    /* --purple (dark) */
    --accent-color: #78b6ad;       /* --accent (dark) */
    --text-primary: #d6d6d6;       /* --text (dark) */
    --text-secondary: #dbd5bc;     /* --text-light (dark) */
    --bg-primary: #222529;         /* --bg (dark) */
    --bg-secondary: #464949;       /* --bg-light (dark) */
    --border-color: #464949;       /* --dimGrey (dark) */
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.3);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.3);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.3);
    --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.3);
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    line-height: 1.6;
    color: var(--text-primary);
    background: var(--bg-primary);
    margin: 0;
    padding: 2rem 1rem;
    overflow-x: hidden; /* No horizontal scrollbar */
    overflow-y: auto; /* Allow vertical scrolling if needed */
}

/* Hero Section */
.hero {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 4rem 2rem;
    text-align: center;
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url('data:image/svg+xml,<svg width="100" height="100" xmlns="http://www.w3.org/2000/svg"><defs><pattern id="grid" width="100" height="100" patternUnits="userSpaceOnUse"><path d="M 100 0 L 0 0 0 100" fill="none" stroke="rgba(255,255,255,0.1)" stroke-width="1"/></pattern></defs><rect width="100" height="100" fill="url(%23grid)"/></svg>');
    opacity: 0.3;
}

.hero-content {
    max-width: 900px;
    margin: 0 auto;
    position: relative;
    z-index: 1;
}

.conference-badge {
    display: inline-block;
    background: rgba(255, 255, 255, 0.2);
    backdrop-filter: blur(10px);
    padding: 0.5rem 1.5rem;
    border-radius: 50px;
    font-weight: 600;
    font-size: 0.9rem;
    margin-bottom: 1.5rem;
    border: 1px solid rgba(255, 255, 255, 0.3);
}

h1 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
    line-height: 1.2;
}

.authors {
    font-size: 1.1rem;
    margin-bottom: 2rem;
    opacity: 0.95;
}

.hero-buttons {
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
    margin-top: 2rem;
}

.btn {
    padding: 0.75rem 2rem;
    border-radius: 8px;
    text-decoration: none;
    font-weight: 600;
    transition: all 0.3s ease;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    cursor: pointer;
    border: none;
    font-size: 1rem;
}

.btn-primary {
    background: white;
    color: #667eea;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.btn-secondary {
    background: rgba(255, 255, 255, 0.2);
    color: white;
    border: 2px solid white;
}

.btn-secondary:hover {
    background: rgba(255, 255, 255, 0.3);
}

/* Container */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1.5rem;
}

/* Section */
.section {
    padding: 3rem 0;
}

.section-title {
    font-size: 2rem;
    font-weight: 700;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.section-subtitle {
    font-size: 1.1rem;
    color: var(--text-secondary);
    margin-bottom: 2rem;
}

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

.card-title {
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

/* Grid Layout */
.grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-top: 2rem;
}

/* Abstract */
.abstract {
    background: var(--bg-primary);
    border-left: 4px solid var(--primary-color);
    padding: 2rem;
    border-radius: 8px;
    box-shadow: var(--shadow-sm);
}

/* Mathematical notation */
.math-block {
    background: var(--bg-secondary);
    padding: 1.5rem;
    border-radius: 8px;
    overflow-x: auto;
    margin: 1.5rem 0;
    border: 1px solid var(--border-color);
}

/* Code block */
.code-block {
    background: #1e293b;
    color: #e2e8f0;
    padding: 1.5rem;
    border-radius: 8px;
    overflow-x: auto;
    margin: 1.5rem 0;
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.9rem;
    line-height: 1.6;
}

.code-block .keyword { color: #c678dd; }
.code-block .function { color: #61afef; }
.code-block .string { color: #98c379; }
.code-block .comment { color: #5c6370; font-style: italic; }
.code-block .number { color: #d19a66; }

/* Interactive Demo */
.demo-controls {
    display: flex;
    flex-wrap: wrap;
    gap: 2rem;
    margin-bottom: 2rem;
    padding: 1.5rem;
    background: var(--bg-secondary);
    border-radius: 8px;
}

.control-group {
    flex: 1;
    min-width: 200px;
}

.control-group label {
    display: block;
    font-weight: 600;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
}

.control-group input {
    width: 100%;
    padding: 0.5rem;
    border: 2px solid var(--border-color);
    border-radius: 6px;
    font-size: 1rem;
    transition: border-color 0.3s ease;
}

.control-group input:focus {
    outline: none;
    border-color: var(--primary-color);
}

.control-group .value-display {
    font-size: 1.2rem;
    font-weight: 600;
    color: var(--primary-color);
}

/* Chart Container */
.chart-container {
    position: relative;
    height: 400px;
    margin: 2rem 0;
    background: var(--bg-primary);
    padding: 1rem;
    border-radius: 8px;
    box-shadow: var(--shadow-sm);
}

/* Stats Grid */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1.5rem;
    margin: 2rem 0;
}

.stat-card {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    padding: 1.5rem;
    border-radius: 12px;
    text-align: center;
    box-shadow: var(--shadow-md);
}

.stat-value {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
}

.stat-label {
    font-size: 0.9rem;
    opacity: 0.9;
    text-transform: uppercase;
    letter-spacing: 1px;
}

/* Methodology Steps */
.methodology-steps {
    counter-reset: step;
}

.step {
    position: relative;
    padding-left: 4rem;
    margin-bottom: 2rem;
    counter-increment: step;
}

.step::before {
    content: counter(step);
    position: absolute;
    left: 0;
    top: 0;
    width: 3rem;
    height: 3rem;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 1.2rem;
}

.step h3 {
    font-size: 1.3rem;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
}

.step p {
    color: var(--text-secondary);
    line-height: 1.8;
}

/* Footer */
footer {
    background: var(--text-primary);
    color: white;
    padding: 3rem 0;
    text-align: center;
}

footer a {
    color: var(--accent-color);
    text-decoration: none;
}

footer a:hover {
    text-decoration: underline;
}

/* Responsive */
@media (max-width: 768px) {
    h1 {
        font-size: 2rem;
    }
    
    .section-title {
        font-size: 1.5rem;
    }
    
    .hero {
        padding: 3rem 1rem;
    }
    
    .container {
        padding: 0 1rem;
    }
}

/* Animations */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.fade-in-up {
    animation: fadeInUp 0.6s ease-out;
}

/* Loading spinner */
.spinner {
    border: 3px solid rgba(0, 0, 0, 0.1);
    border-left-color: var(--primary-color);
    border-radius: 50%;
    width: 40px;
    height: 40px;
    animation: spin 1s linear infinite;
    margin: 2rem auto;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}