/* Modern Design System for Jan Ullmann's Website */

:root {
    --primary-color: #1e40af;
    --secondary-color: #3b82f6;
 .nav-item:hover {
    background: linear-gradient(135deg, #dbeafe 0%, #bfdbfe 100%);
    transform: translateX(5px);
}-accent-color: #0ea5e9;
    --success-color: #0284c7;
    --warning-color: #0369a1;
    --text-dark: #1e3a8a;
    --text-light: #475569;
    --bg-gradient: linear-gradient(135deg, #1e40af 0%, #3b82f6 50%, #0ea5e9 100%);
    --card-shadow: 0 10px 25px rgba(30, 64, 175, 0.15);
    --border-radius: 16px;
    --transition: all 0.3s ease;
}

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

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    line-height: 1.7;
    color: var(--text-dark);
    background: linear-gradient(135deg, #f0f9ff 0%, #e0f2fe 50%, #bae6fd 100%);
    min-height: 100vh;
}

/* Hero Sections */
.hero-section {
    background: var(--bg-gradient);
    padding: 3rem 0;
    margin-bottom: 2rem;
    position: relative;
    overflow: hidden;
}

.hero-section::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100"><defs><pattern id="grid" width="10" height="10" patternUnits="userSpaceOnUse"><path d="M 10 0 L 0 0 0 10" fill="none" stroke="rgba(255,255,255,0.1)" stroke-width="0.5"/></pattern></defs><rect width="100" height="100" fill="url(%23grid)"/></svg>');
    opacity: 0.3;
}

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

.hero-title {
    font-size: 3rem;
    font-weight: 700;
    color: white;
    margin-bottom: 1rem;
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

.hero-subtitle {
    font-size: 1.1rem;
    color: rgba(255, 255, 255, 0.9);
    font-weight: 300;
}

/* Cards */
.content-card {
    background: white;
    border-radius: var(--border-radius);
    box-shadow: var(--card-shadow);
    border: none;
    transition: var(--transition);
    overflow: hidden;
    margin-bottom: 2rem;
}

.content-card:hover {
    transform: translateY(-2px);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.15);
}

/* Navigation Elements */
.back-button {
    background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
    border: none;
    border-radius: 12px;
    padding: 0.75rem 1.5rem;
    color: white;
    text-decoration: none;
    font-weight: 500;
    transition: var(--transition);
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    margin-bottom: 1.5rem;
}

.back-button:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 20px rgba(30, 64, 175, 0.4);
    color: white;
    text-decoration: none;
}

/* Table of Contents */
.toc-list {
    border: none;
    border-radius: var(--border-radius);
    overflow: hidden;
}

.nav-item {
    border: none;
    border-bottom: 1px solid #bfdbfe;
    transition: var(--transition);
}

.toc-item:last-child {
    border-bottom: none;
}

.toc-item:hover {
    background: linear-gradient(135deg, #dbeafe 0%, #bfdbfe 100%);
    transform: translateX(5px);
}

.toc-link {
    color: var(--text-dark);
    font-weight: 500;
    text-decoration: none;
    padding: 1rem 1.5rem;
    display: flex;
    align-items: center;
    transition: var(--transition);
}

.toc-link:hover {
    color: var(--primary-color);
    text-decoration: none;
}

.toc-link i {
    margin-right: 0.75rem;
    font-size: 1.1rem;
    color: var(--accent-color);
}

/* Publication/Content Cards */
.publication-card {
    background: white;
    border-radius: var(--border-radius);
    box-shadow: var(--card-shadow);
    border: none;
    margin-bottom: 2rem;
    overflow: hidden;
    transition: var(--transition);
}

.publication-card:hover {
    transform: translateY(-3px);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.15);
}

.publication-header {
    background: linear-gradient(135deg, #dbeafe 0%, #bfdbfe 100%);
    padding: 1.5rem;
    border-bottom: 1px solid #93c5fd;
}

.publication-title {
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--text-dark);
    margin-bottom: 0.5rem;
}

.publication-body {
    padding: 2rem;
}

/* Buttons */
.btn-modern {
    background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
    border: none;
    border-radius: 12px;
    padding: 0.75rem 1.5rem;
    color: white;
    font-weight: 500;
    transition: var(--transition);
    text-decoration: none;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
}

.btn-modern:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 20px rgba(30, 64, 175, 0.4);
    color: white;
    text-decoration: none;
}

.btn-modern-small {
    padding: 0.5rem 1rem;
    font-size: 0.9rem;
}

.btn-modern-secondary {
    background: linear-gradient(135deg, #0284c7, #0369a1);
}

.btn-modern-secondary:hover {
    box-shadow: 0 8px 20px rgba(2, 132, 199, 0.4);
}

/* Contact Information */
.contact-card {
    background: linear-gradient(135deg, #1e3a8a 0%, #1e40af 50%, #3b82f6 100%);
    color: white;
    padding: 2rem;
    border-radius: var(--border-radius);
    margin-top: 2rem;
}

.contact-title {
    font-size: 1.75rem;
    font-weight: 600;
    margin-bottom: 1rem;
}

.contact-links {
    display: flex;
    flex-wrap: wrap;
    gap: 1rem;
    align-items: center;
}

.contact-link {
    color: rgba(255, 255, 255, 0.9);
    text-decoration: none;
    transition: var(--transition);
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.5rem 1rem;
    border-radius: 8px;
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
}

.contact-link:hover {
    color: white;
    background: rgba(255, 255, 255, 0.2);
    transform: translateY(-2px);
    text-decoration: none;
}

/* PDF Embeds */
.pdf-container {
    border-radius: var(--border-radius);
    overflow: hidden;
    margin: 1.5rem 0;
    box-shadow: var(--card-shadow);
}

.pdf-embed {
    width: 100%;
    height: 600px;
    border: none;
}

/* Images */
.university-logo {
    max-width: 250px;
    height: auto;
    transition: var(--transition);
}

.project-logo {
    max-width: 200px;
    height: auto;
    transition: var(--transition);
}

.workshop-logo {
    max-width: 120px;
    height: auto;
    transition: var(--transition);
}

/* Text Styles */
.text-justify {
    text-align: justify;
}

.description-text {
    font-size: 1.1rem;
    line-height: 1.8;
    color: var(--text-light);
}

/* Workshop/Course Cards */
.workshop-card {
    background: white;
    border-radius: var(--border-radius);
    padding: 2rem;
    margin-bottom: 2rem;
    box-shadow: var(--card-shadow);
    transition: var(--transition);
}

.workshop-card:hover {
    transform: translateY(-2px);
    box-shadow: 0 15px 30px rgba(0, 0, 0, 0.12);
}

.workshop-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 1rem;
}

.workshop-title {
    font-size: 1.4rem;
    font-weight: 600;
    color: var(--text-dark);
    margin: 0;
}

.workshop-divider {
    height: 2px;
    background: linear-gradient(135deg, #1e40af, #3b82f6);
    border: none;
    border-radius: 1px;
    margin: 1.5rem 0;
}

/* Responsive Design */
@media (max-width: 768px) {
    .hero-title {
        font-size: 2.5rem;
    }
    
    .hero-subtitle {
        font-size: 1rem;
    }
    
    .university-logo, .project-logo {
        max-width: 180px;
    }
    
    .workshop-logo {
        max-width: 80px;
    }
    
    .contact-links {
        flex-direction: column;
        align-items: stretch;
    }
    
    .workshop-header {
        flex-direction: column;
        align-items: flex-start;
        gap: 1rem;
    }
    
    .publication-body {
        padding: 1.5rem;
    }
}

@media (max-width: 576px) {
    .hero-section {
        padding: 2rem 0;
    }
    
    .hero-title {
        font-size: 2rem;
    }
    
    .content-card, .workshop-card {
        margin-bottom: 1.5rem;
    }
}

/* Utility Classes */
.shadow-modern {
    box-shadow: var(--card-shadow);
}

.rounded-modern {
    border-radius: var(--border-radius);
}

.transition-modern {
    transition: var(--transition);
}

/* Animation for page load */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.content-card, .workshop-card, .publication-card {
    animation: fadeInUp 0.6s ease-out;
}

.content-card:nth-child(2) {
    animation-delay: 0.1s;
}

.content-card:nth-child(3) {
    animation-delay: 0.2s;
}

.content-card:nth-child(4) {
    animation-delay: 0.3s;
}