:root {
    --primary-color: #4f46e5; /* Indigo */
    --primary-hover: #4338ca;
    --text-color: #1e293b; /* Slate 800 */
    --text-muted: #64748b; /* Slate 500 */
    --bg-color: #ffffff;
    --bg-light: #f8fafc; /* Slate 50 */
    --bg-dark: #0f172a; /* Slate 900 */
    --text-white: #f8fafc;
    --container-width: 1200px;
    --font-main: 'Inter', system-ui, -apple-system, sans-serif;
    --transition: all 0.3s ease;
}

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

body {
    font-family: var(--font-main);
    color: var(--text-color);
    background-color: var(--bg-color);
    line-height: 1.6;
    overflow-x: hidden;
}

.container {
    max-width: var(--container-width);
    margin: 0 auto;
    padding: 0 20px;
}

section {
    padding: 80px 0;
}

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

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

.text-white {
    color: var(--text-white);
}

/* Header & Nav */
header {
    background-color: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid #e2e8f0;
    position: sticky;
    top: 0;
    z-index: 1000;
}

nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 70px;
}

.logo a {
    text-decoration: none;
    font-size: 1.5rem;
    font-weight: 800;
    color: var(--text-color);
    letter-spacing: -1px;
}

.logo span {
    color: var(--primary-color);
}

.nav-links {
    display: flex;
    list-style: none;
}

.nav-links li {
    margin-left: 30px;
}

.nav-links a {
    text-decoration: none;
    color: var(--text-color);
    font-weight: 500;
    font-size: 0.95rem;
    transition: var(--transition);
}

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

.menu-toggle {
    display: none;
    cursor: pointer;
}

/* Hero Section */
.hero-section {
    padding: 120px 0 100px;
    text-align: center;
}

.hero-section h1 {
    font-size: 4rem;
    font-weight: 900;
    line-height: 1.1;
    margin-bottom: 20px;
    letter-spacing: -2px;
}

.hero-section h1 span {
    color: var(--primary-color);
}

.subtitle {
    font-size: 1.25rem;
    color: var(--text-muted);
    max-width: 800px;
    margin: 0 auto 40px;
}

.hero-cta {
    display: flex;
    justify-content: center;
    gap: 20px;
}

.btn {
    padding: 14px 28px;
    border-radius: 8px;
    text-decoration: none;
    font-weight: 600;
    font-size: 1rem;
    transition: var(--transition);
    cursor: pointer;
}

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

.btn.primary:hover {
    background-color: var(--primary-hover);
    transform: translateY(-2px);
    box-shadow: 0 10px 15px -3px rgba(79, 70, 229, 0.2);
}

.btn.secondary {
    background-color: transparent;
    border: 1px solid #e2e8f0;
    color: var(--text-color);
}

.btn.secondary:hover {
    background-color: #f1f5f9;
}

/* Methodology */
.section-title {
    font-size: 2.25rem;
    font-weight: 800;
    margin-bottom: 50px;
    letter-spacing: -1px;
    text-align: center;
}

.methods-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 40px;
}

.method-card {
    padding: 30px;
    border-radius: 12px;
    background: white;
    border: 1px solid #e2e8f0;
    transition: var(--transition);
}

.method-card:hover {
    transform: translateY(-5px);
    border-color: var(--primary-color);
}

.method-card h3 {
    font-size: 1.5rem;
    margin-bottom: 15px;
    font-weight: 700;
}

.method-card p {
    color: var(--text-muted);
}

/* Projects */
.projects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 30px;
}

.project-card {
    background: white;
    border-radius: 16px;
    overflow: hidden;
    border: 1px solid #e2e8f0;
    transition: var(--transition);
    position: relative;
}

.project-card:hover {
    transform: scale(1.02);
    box-shadow: 0 20px 25px -5px rgba(0, 0, 0, 0.05);
}

.project-content {
    padding: 40px;
}

.tag {
    display: inline-block;
    padding: 4px 12px;
    background: #eef2ff;
    color: var(--primary-color);
    border-radius: 20px;
    font-size: 0.75rem;
    font-weight: 700;
    text-transform: uppercase;
    margin-bottom: 15px;
}

.project-card h3 {
    font-size: 1.5rem;
    margin-bottom: 10px;
}

.project-card p {
    color: var(--text-muted);
    margin-bottom: 20px;
}

.read-more {
    text-decoration: none;
    color: var(--primary-color);
    font-weight: 600;
}

/* Blog List */
.blog-list {
    max-width: 900px;
    margin: 0 auto;
}

.blog-item {
    padding: 30px 0;
    border-bottom: 1px solid #e2e8f0;
}

.blog-item .date {
    font-size: 0.85rem;
    color: var(--text-muted);
    font-weight: 500;
}

.blog-item h3 {
    font-size: 1.75rem;
    margin: 10px 0;
}

.blog-item h3 a {
    text-decoration: none;
    color: var(--text-color);
    transition: var(--transition);
}

.blog-item h3 a:hover {
    color: var(--primary-color);
}

.blog-item p {
    color: var(--text-muted);
}

.section-header {
    display: flex;
    justify-content: space-between;
    align-items: baseline;
    margin-bottom: 30px;
}

.btn-link {
    text-decoration: none;
    color: var(--primary-color);
    font-weight: 700;
}

/* Team Tags */
.team-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 15px;
    margin-top: 30px;
}

.team-tags span {
    padding: 10px 20px;
    background: rgba(255, 255, 255, 0.1);
    border: 1px solid rgba(255, 255, 255, 0.2);
    border-radius: 8px;
    font-weight: 500;
}

/* Footer */
footer {
    padding: 60px 0;
    border-top: 1px solid #e2e8f0;
}

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

.social-links a {
    margin-left: 20px;
    text-decoration: none;
    color: var(--text-muted);
    font-weight: 500;
    transition: var(--transition);
}

.social-links a:hover {
    color: var(--primary-color);
}

/* Mobile Responsive */
@media (max-width: 768px) {
    .hero-section h1 {
        font-size: 2.5rem;
    }
    
    .hero-cta {
        flex-direction: column;
    }
    
    .nav-links {
        display: none;
    }
    
    .menu-toggle {
        display: block;
    }
    
    .footer-content {
        flex-direction: column;
        gap: 20px;
        text-align: center;
    }
    
    .social-links a {
        margin: 0 10px;
    }
}