/* Reset and base styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary-color: #2563eb;
    --primary-dark: #1d4ed8;
    --secondary-color: #f59e0b;
    --accent-color: #10b981;
    --text-dark: #1f2937;
    --text-light: #6b7280;
    --bg-light: #f9fafb;
    --bg-white: #ffffff;
    --border-color: #e5e7eb;
    --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);
    --gradient-primary: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-dark) 100%);
    --gradient-secondary: linear-gradient(135deg, var(--secondary-color) 0%, #ea580c 100%);
}

body {
    font-family: 'Inter', sans-serif;
    line-height: 1.6;
    color: var(--text-dark);
    scroll-behavior: smooth;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Navigation */
.header {
    position: fixed;
    top: 0;
    width: 100%;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border-color);
    z-index: 1000;
    transition: all 0.3s ease;
}

.nav-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 2rem;
    max-width: 1200px;
    margin: 0 auto;
}

.logo h1 {
    color: var(--primary-color);
    font-size: 1.5rem;
    font-weight: 700;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 2rem;
}

.nav-link {
    text-decoration: none;
    color: var(--text-dark);
    font-weight: 500;
    transition: color 0.3s ease;
    position: relative;
}

.nav-link:hover {
    color: var(--primary-color);
}

.nav-link::after {
    content: '';
    position: absolute;
    width: 0;
    height: 2px;
    bottom: -5px;
    left: 0;
    background: var(--primary-color);
    transition: width 0.3s ease;
}

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

.hamburger {
    display: none;
    flex-direction: column;
    cursor: pointer;
}

.bar {
    width: 25px;
    height: 3px;
    background: var(--text-dark);
    margin: 3px 0;
    transition: 0.3s;
}

/* Hero Section */
.hero {
    background: var(--gradient-primary);
    color: white;
    padding: 150px 0 100px;
    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 xmlns="http://www.w3.org/2000/svg" viewBox="0 0 1000 1000"><polygon fill="rgba(255,255,255,0.1)" points="0,1000 1000,800 1000,1000"/></svg>');
    background-size: cover;
}

.hero-content {
    position: relative;
    z-index: 2;
    max-width: 800px;
    margin: 0 auto;
    padding: 0 20px;
}

.hero-title {
    font-size: 3.5rem;
    font-weight: 700;
    margin-bottom: 1.5rem;
    line-height: 1.2;
}

.hero-subtitle {
    font-size: 1.25rem;
    margin-bottom: 2.5rem;
    opacity: 0.9;
    line-height: 1.6;
}

.hero-buttons {
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
    margin-bottom: 3rem;
}

.btn {
    padding: 12px 30px;
    border-radius: 8px;
    text-decoration: none;
    font-weight: 600;
    transition: all 0.3s ease;
    display: inline-block;
    border: none;
    cursor: pointer;
    font-size: 1rem;
}

.btn-primary {
    background: white;
    color: var(--primary-color);
    box-shadow: var(--shadow-md);
}

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

.btn-secondary {
    background: transparent;
    color: white;
    border: 2px solid white;
}

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

.hero-stats {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
    gap: 1.5rem;
    max-width: 800px;
    margin: 0 auto;
    position: relative;
    z-index: 2;
}

.stat {
    text-align: center;
}

.stat h3 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
    color: var(--secondary-color);
}

.stat p {
    font-size: 0.9rem;
    opacity: 0.9;
}

/* Section Styles */
section {
    padding: 80px 0;
}

.section-title {
    font-size: 2.5rem;
    font-weight: 700;
    text-align: center;
    margin-bottom: 3rem;
    color: var(--text-dark);
}

.section-subtitle {
    font-size: 1.125rem;
    text-align: center;
    color: var(--text-light);
    margin-bottom: 3rem;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

/* Research Section */
.research {
    background: var(--bg-light);
}

.research-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 2rem;
}

.research-card {
    background: white;
    padding: 2rem;
    border-radius: 12px;
    box-shadow: var(--shadow-md);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    border: 1px solid var(--border-color);
}

.research-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

.research-icon {
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

.research-card h3 {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 1rem;
    color: var(--text-dark);
}

.research-card p {
    color: var(--text-light);
    margin-bottom: 1rem;
    line-height: 1.6;
}

.research-card cite {
    font-size: 0.85rem;
    color: var(--text-light);
    font-style: italic;
    border-left: 3px solid var(--primary-color);
    padding-left: 1rem;
    display: block;
}

/* Benefits Section */
.benefits-content {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: 4rem;
    align-items: start;
}

.benefit-item {
    display: flex;
    gap: 1.5rem;
    margin-bottom: 2rem;
    padding-bottom: 2rem;
    border-bottom: 1px solid var(--border-color);
}

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

.benefit-number {
    background: var(--gradient-primary);
    color: white;
    width: 50px;
    height: 50px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 1.1rem;
    flex-shrink: 0;
}

.benefit-text h3 {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
    color: var(--text-dark);
}

.benefit-text p {
    color: var(--text-light);
    line-height: 1.6;
}

.stats-highlight {
    background: var(--gradient-secondary);
    color: white;
    padding: 2rem;
    border-radius: 12px;
    box-shadow: var(--shadow-lg);
}

.stats-highlight h3 {
    font-size: 1.5rem;
    margin-bottom: 1.5rem;
}

.stats-highlight ul {
    list-style: none;
}

.stats-highlight li {
    padding: 0.5rem 0;
    position: relative;
    padding-left: 1.5rem;
}

.stats-highlight li::before {
    content: '✓';
    position: absolute;
    left: 0;
    color: white;
    font-weight: bold;
}

/* Testimonials Section */
.testimonials {
    background: var(--bg-light);
}

.testimonials-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
}

.testimonial-card {
    background: white;
    padding: 2rem;
    border-radius: 12px;
    box-shadow: var(--shadow-md);
    position: relative;
    border-left: 4px solid var(--primary-color);
}

.testimonial-content p {
    font-size: 1.1rem;
    line-height: 1.6;
    color: var(--text-dark);
    margin-bottom: 1.5rem;
    font-style: italic;
}

.testimonial-author {
    display: flex;
    flex-direction: column;
    gap: 0.25rem;
}

.testimonial-author strong {
    color: var(--text-dark);
    font-weight: 600;
}

.testimonial-author span {
    color: var(--text-light);
    font-size: 0.9rem;
}

/* Form Section */
.submit-section {
    background: white;
}

.testimonial-form {
    max-width: 800px;
    margin: 0 auto;
    background: var(--bg-light);
    padding: 3rem;
    border-radius: 12px;
    box-shadow: var(--shadow-md);
}

.form-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1.5rem;
    margin-bottom: 1.5rem;
}

.form-group {
    display: flex;
    flex-direction: column;
    margin-bottom: 1.5rem;
}

.form-group label {
    font-weight: 600;
    color: var(--text-dark);
    margin-bottom: 0.5rem;
}

.form-group input,
.form-group select,
.form-group textarea {
    padding: 12px;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    font-size: 1rem;
    transition: border-color 0.3s ease, box-shadow 0.3s ease;
    background: white;
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

.form-group small {
    color: var(--text-light);
    font-size: 0.85rem;
    margin-top: 0.25rem;
}

.checkbox-group {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 0.5rem;
    margin-top: 0.5rem;
}

.checkbox-group label {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-weight: normal;
    margin-bottom: 0;
}

.checkbox-group input[type="checkbox"] {
    width: auto;
    margin: 0;
}

.form-message {
    margin-top: 1rem;
    padding: 1rem;
    border-radius: 8px;
    text-align: center;
    font-weight: 600;
    display: none;
}

.form-message.success {
    background: #d1fae5;
    color: #065f46;
    border: 1px solid #a7f3d0;
}

.form-message.error {
    background: #fee2e2;
    color: #991b1b;
    border: 1px solid #fca5a5;
}

/* Footer */
.footer {
    background: var(--text-dark);
    color: white;
    padding: 3rem 0 1rem;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-bottom: 2rem;
}

.footer-section h3,
.footer-section h4 {
    margin-bottom: 1rem;
    color: white;
}

.footer-section p {
    color: #d1d5db;
    line-height: 1.6;
}

.footer-section ul {
    list-style: none;
}

.footer-section ul li {
    margin-bottom: 0.5rem;
}

.footer-section ul li a {
    color: #d1d5db;
    text-decoration: none;
    transition: color 0.3s ease;
}

.footer-section ul li a:hover {
    color: white;
}

.footer-bottom {
    border-top: 1px solid #374151;
    padding-top: 1rem;
    text-align: center;
    color: #9ca3af;
    font-size: 0.9rem;
}

/* Responsive Design */
@media (max-width: 768px) {
    .hamburger {
        display: flex;
    }
    
    .nav-menu {
        position: fixed;
        left: -100%;
        top: 70px;
        flex-direction: column;
        background: white;
        width: 100%;
        text-align: center;
        transition: 0.3s;
        box-shadow: var(--shadow-lg);
        padding: 2rem 0;
    }
    
    .nav-menu.active {
        left: 0;
    }
    
    .nav-menu li {
        margin: 1rem 0;
    }
    
    .hero-title {
        font-size: 2.5rem;
    }
    
    .hero-buttons {
        flex-direction: column;
        align-items: center;
    }
    
    .btn {
        width: 200px;
    }
    
    .section-title {
        font-size: 2rem;
    }
    
    .research-grid,
    .testimonials-grid {
        grid-template-columns: 1fr;
    }
    
    .benefits-content {
        grid-template-columns: 1fr;
        gap: 2rem;
    }
    
    .form-row {
        grid-template-columns: 1fr;
    }
    
    .checkbox-group {
        grid-template-columns: 1fr;
    }
    
    .testimonial-form {
        padding: 2rem 1rem;
    }
    
    .hero-stats {
        grid-template-columns: 1fr;
    }
    
    .nav-container {
        padding: 1rem;
    }
    
    .container {
        padding: 0 15px;
    }
}

@media (max-width: 480px) {
    .hero-title {
        font-size: 2rem;
    }
    
    .hero-subtitle {
        font-size: 1rem;
    }
    
    .hero {
        padding: 120px 0 80px;
    }
    
    section {
        padding: 60px 0;
    }
    
    .research-card,
    .testimonial-card {
        padding: 1.5rem;
    }
    
    .testimonial-form {
        padding: 1.5rem;
    }
}

/* Animation for smooth scrolling and loading */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.research-card,
.testimonial-card,
.benefit-item {
    animation: fadeInUp 0.6s ease-out;
}

/* Loading state for form */
.btn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
}

.btn.loading::after {
    content: '';
    width: 16px;
    height: 16px;
    margin-left: 8px;
    border: 2px solid transparent;
    border-top: 2px solid currentColor;
    border-radius: 50%;
    animation: spin 1s linear infinite;
    display: inline-block;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}