:root {
    --bg-main: #ffffff;
    --bg-light: #f8fafc;
    --bg-dark: #1e293b;
    --text-main: #334155;
    --text-heading: #0f172a;
    --text-light: #f8fafc;
    --accent: #2563eb;
    --accent-hover: #1d4ed8;
    --border: #e2e8f0;
    --font-heading: 'Playfair Display', serif;
    --font-body: 'Inter', sans-serif;
    --transition: all 0.3s ease;
}

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

body {
    font-family: var(--font-body);
    color: var(--text-main);
    background-color: var(--bg-main);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
}

h1, h2, h3, h4, h5 {
    color: var(--text-heading);
    font-weight: 600;
    line-height: 1.2;
}

h1, h2, .section-heading {
    font-family: var(--font-heading);
}

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

/* Utilities */
.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 5%;
}

.section {
    padding: 100px 0;
}

.bg-light { background-color: var(--bg-light); }
.bg-dark { background-color: var(--bg-dark); }
.text-white { color: var(--text-light); }
.text-center { text-align: center; }

.section-heading {
    font-size: 2.5rem;
    margin-bottom: 3rem;
    position: relative;
    display: inline-block;
}

.section-heading::after {
    content: '';
    position: absolute;
    bottom: -10px;
    left: 0;
    width: 60px;
    height: 3px;
    background-color: var(--accent);
}

.section-heading.light {
    color: var(--text-light);
}

.section-heading.light::after {
    left: 50%;
    transform: translateX(-50%);
}

/* Buttons */
.btn-primary, .btn-outline {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 12px 24px;
    border-radius: 4px;
    font-weight: 500;
    cursor: pointer;
    transition: var(--transition);
    border: 2px solid transparent;
}

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

.btn-primary:hover {
    background-color: var(--accent-hover);
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(37, 99, 235, 0.2);
    color: white;
}

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

.btn-outline.light {
    border-color: rgba(255,255,255,0.3);
    color: white;
}

.btn-outline.light:hover {
    background-color: rgba(255,255,255,0.1);
    border-color: white;
}

.btn-large {
    padding: 16px 32px;
    font-size: 1.1rem;
}

/* Navbar */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    background-color: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    z-index: 1000;
    border-bottom: 1px solid var(--border);
    transition: var(--transition);
}

.navbar.scrolled {
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.05);
}

.nav-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 80px;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 5%;
}

.logo {
    font-family: var(--font-heading);
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--text-heading);
}

.nav-links {
    display: flex;
    align-items: center;
    gap: 2rem;
}

.nav-links a:not(.btn-primary) {
    color: var(--text-main);
    font-weight: 500;
    font-size: 0.95rem;
}

.nav-links a:not(.btn-primary):hover {
    color: var(--accent);
}

.lang-selector {
    display: flex;
    gap: 0.5rem;
    margin-left: 1rem;
    border-left: 1px solid var(--border);
    padding-left: 1.5rem;
}

.lang-btn {
    background: none;
    border: none;
    font-family: var(--font-body);
    font-size: 0.85rem;
    font-weight: 500;
    color: var(--text-main);
    cursor: pointer;
    opacity: 0.6;
    transition: var(--transition);
}

.lang-btn:hover, .lang-btn.active {
    opacity: 1;
    color: var(--accent);
}

.mobile-menu-btn {
    display: none;
    background: none;
    border: none;
    cursor: pointer;
    color: var(--text-heading);
}

/* Hero */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    padding-top: 80px;
    background: linear-gradient(135deg, #f8fafc 0%, #e2e8f0 100%);
    overflow: hidden;
}

.hero-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: center;
}

.hero-text h1 {
    font-size: 4rem;
    margin-bottom: 1rem;
    letter-spacing: -0.02em;
}

.hero-text h2 {
    font-size: 1.5rem;
    color: var(--accent);
    font-family: var(--font-body);
    font-weight: 400;
    margin-bottom: 1.5rem;
}

.lead {
    font-size: 1.2rem;
    color: var(--text-main);
    margin-bottom: 2.5rem;
    max-width: 500px;
}

.hero-image-container {
    position: relative;
    border-radius: 8px;
    overflow: hidden;
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.1);
    aspect-ratio: 4/5;
}

.hero-image {
    width: 100%;
    height: 100%;
    object-fit: cover;
    display: block;
}

/* About Section */
.about-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 2rem;
}

.about-card {
    background: var(--bg-main);
    padding: 2.5rem;
    border-radius: 8px;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.02);
    border: 1px solid var(--border);
    transition: var(--transition);
}

.about-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.05);
}

.about-card h4 {
    font-size: 1.25rem;
    margin-bottom: 1rem;
    color: var(--accent);
}

/* Services */
.services-list {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
    max-width: 800px;
}

.service-item {
    padding: 2rem;
    border-left: 4px solid var(--accent);
    background: var(--bg-light);
    border-radius: 0 8px 8px 0;
    transition: var(--transition);
}

.service-item:hover {
    background: white;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.05);
}

.service-header h4 {
    font-size: 1.5rem;
    margin-bottom: 0.5rem;
}

/* Pricing Section */
.pricing-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 2rem;
    max-width: 900px;
    margin: 0 auto;
}

.pricing-card {
    background: var(--bg-main);
    padding: 3rem 2.5rem;
    border-radius: 8px;
    text-align: center;
    border: 1px solid var(--border);
    transition: var(--transition);
}

.pricing-card.premium {
    background: var(--bg-dark);
    color: var(--text-light);
    border: none;
    transform: scale(1.05);
    box-shadow: 0 20px 40px rgba(0,0,0,0.1);
}

.pricing-card.premium h4, .pricing-card.premium p {
    color: var(--text-light);
}

.price {
    font-size: 3.5rem;
    font-weight: 600;
    font-family: var(--font-heading);
    color: var(--text-heading);
    margin-bottom: 0.5rem;
}

.pricing-card.premium .price {
    color: white;
}

.vat {
    font-size: 1rem;
    font-family: var(--font-body);
    font-weight: 400;
    opacity: 0.8;
}

.price-desc {
    font-size: 0.9rem;
    text-transform: uppercase;
    letter-spacing: 1px;
    color: var(--accent);
    font-weight: 500;
    margin-bottom: 2rem;
}

.pricing-card.premium .price-desc {
    color: #93c5fd;
}

.pricing-card h4 {
    font-size: 1.5rem;
    margin-bottom: 1rem;
}

/* Research */
.research-content {
    max-width: 800px;
}

.pub-tag {
    display: inline-block;
    padding: 4px 12px;
    background: #e0e7ff;
    color: var(--accent);
    border-radius: 50px;
    font-size: 0.85rem;
    font-weight: 600;
    margin-bottom: 1rem;
}

.publication-item {
    margin-bottom: 3rem;
}

.publication-item h4 {
    font-size: 1.5rem;
    margin-bottom: 1rem;
}

.sub-heading {
    font-size: 1.25rem;
    margin-bottom: 1.5rem;
    color: var(--text-main);
}

.paper-card {
    display: flex;
    align-items: center;
    padding: 1.5rem;
    border: 1px solid var(--border);
    border-radius: 8px;
    gap: 1.5rem;
    background: var(--bg-light);
    color: var(--text-main);
}

.paper-card:hover {
    background: white;
    border-color: var(--accent);
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.05);
}

.paper-icon {
    color: var(--accent);
}

.link-url {
    display: block;
    font-size: 0.85rem;
    color: #64748b;
    margin-top: 0.25rem;
}

/* Booking */
.booking-text {
    font-size: 1.2rem;
    max-width: 600px;
    margin: 0 auto 3rem;
    opacity: 0.9;
}

.booking-actions {
    display: flex;
    gap: 1.5rem;
    justify-content: center;
    flex-wrap: wrap;
    margin-bottom: 3rem;
}

.legal-disclaimer {
    font-size: 0.85rem;
    opacity: 0.6;
}

/* Footer */
.footer {
    background: var(--bg-main);
    padding: 2rem 0;
    border-top: 1px solid var(--border);
}

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

.footer-brand h4 {
    margin-bottom: 0.25rem;
}

/* Animations */
.fade-in-up {
    animation: fadeInUp 0.8s ease forwards;
}

.fade-in-image {
    animation: fadeIn 1.2s ease forwards;
}

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

@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

/* Responsive */
@media (max-width: 900px) {
    .hero-content {
        grid-template-columns: 1fr;
        text-align: center;
    }
    
    .hero-text h1 {
        font-size: 3rem;
    }
    
    .hero-actions {
        justify-content: center;
    }
    
    .pricing-grid {
        grid-template-columns: 1fr;
    }
    
    .pricing-card.premium {
        transform: none;
    }
}

@media (max-width: 768px) {
    .nav-links {
        display: none; /* Mobile menu implementation needed in JS */
    }
    
    .mobile-menu-btn {
        display: block;
    }
    
    .about-grid {
        grid-template-columns: 1fr;
    }
    
    .section {
        padding: 60px 0;
    }
}