:root {
    --primary-color: #0066cc;
    --secondary-color: #003d99;
    --text-dark: #1a1a1a;
    --text-light: #666666;
    --bg-light: #f8f9fa;
    --border-color: #e0e0e0;
    --shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    line-height: 1.6;
    color: var(--text-dark);
    background-color: #ffffff;
}

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

/* Navbar */
.navbar {
    background: white;
    box-shadow: var(--shadow);
    position: sticky;
    top: 0;
    z-index: 100;
}

.navbar .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 20px;
}

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

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

.nav-links a {
    text-decoration: none;
    color: var(--text-dark);
    transition: color 0.3s;
}

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

/* Hero Section */
.hero {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
    color: white;
    padding: 6rem 20px;
    text-align: center;
}

.hero h1 {
    font-size: 3rem;
    margin-bottom: 0.5rem;
}

.hero .tagline {
    font-size: 1.25rem;
    margin-bottom: 0.5rem;
    opacity: 0.95;
}

.hero .subtitle {
    font-size: 1rem;
    opacity: 0.9;
    margin-bottom: 2rem;
}

.cta-buttons {
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
}

.btn {
    padding: 0.75rem 1.5rem;
    border-radius: 0.5rem;
    text-decoration: none;
    font-weight: 500;
    transition: all 0.3s;
    display: inline-block;
}

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

.btn-primary:hover {
    background: var(--bg-light);
    transform: translateY(-2px);
}

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

.btn-secondary:hover {
    background: white;
    color: var(--primary-color);
    transform: translateY(-2px);
}

/* About Section */
.about {
    padding: 4rem 20px;
    background: var(--bg-light);
}

.about h2 {
    font-size: 2.5rem;
    margin-bottom: 1.5rem;
    text-align: center;
}

.about > .container > p {
    font-size: 1.1rem;
    text-align: center;
    margin-bottom: 2rem;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
    color: var(--text-light);
}

.about-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2rem;
}

.about-card {
    background: white;
    padding: 2rem;
    border-radius: 0.5rem;
    box-shadow: var(--shadow);
    text-align: center;
}

.about-card h3 {
    font-size: 1.5rem;
    margin-bottom: 1rem;
}

.about-card p {
    color: var(--text-light);
}

/* Projects Section */
.projects {
    padding: 4rem 20px;
}

.projects h2 {
    font-size: 2.5rem;
    margin-bottom: 3rem;
    text-align: center;
}

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

.project-card {
    background: white;
    border: 1px solid var(--border-color);
    border-radius: 0.5rem;
    padding: 2rem;
    transition: all 0.3s;
}

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

.project-header {
    display: flex;
    justify-content: space-between;
    align-items: start;
    margin-bottom: 1rem;
    gap: 1rem;
}

.project-card h3 {
    font-size: 1.3rem;
    margin-bottom: 0.5rem;
}

.badge {
    background: var(--bg-light);
    padding: 0.25rem 0.75rem;
    border-radius: 0.25rem;
    font-size: 0.8rem;
    color: var(--text-light);
    white-space: nowrap;
}

.project-card p {
    color: var(--text-light);
    margin-bottom: 1.5rem;
    line-height: 1.5;
}

.tech-stack {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.tech-tag {
    background: var(--primary-color);
    color: white;
    padding: 0.25rem 0.75rem;
    border-radius: 0.25rem;
    font-size: 0.8rem;
}

/* Skills Section */
.skills {
    padding: 4rem 20px;
    background: var(--bg-light);
}

.skills h2 {
    font-size: 2.5rem;
    margin-bottom: 3rem;
    text-align: center;
}

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

.skill-category {
    background: white;
    padding: 2rem;
    border-radius: 0.5rem;
    box-shadow: var(--shadow);
}

.skill-category h3 {
    color: var(--primary-color);
    margin-bottom: 1rem;
    font-size: 1.2rem;
}

.skill-category ul {
    list-style: none;
}

.skill-category li {
    padding: 0.5rem 0;
    color: var(--text-light);
}

.skill-category li:before {
    content: "✓ ";
    color: var(--primary-color);
    font-weight: bold;
    margin-right: 0.5rem;
}

/* Footer */
.footer {
    background: var(--text-dark);
    color: white;
    padding: 3rem 20px;
    text-align: center;
}

.footer h2 {
    font-size: 2rem;
    margin-bottom: 1rem;
}

.footer p {
    margin-bottom: 1.5rem;
}

.contact-links {
    display: flex;
    gap: 2rem;
    justify-content: center;
    margin-bottom: 2rem;
    flex-wrap: wrap;
}

.contact-links a {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.3s;
}

.contact-links a:hover {
    color: white;
}

.copyright {
    font-size: 0.9rem;
    color: #999;
    margin-top: 2rem;
    padding-top: 2rem;
    border-top: 1px solid #333;
}

/* Responsive */
@media (max-width: 768px) {
    .hero h1 {
        font-size: 2rem;
    }

    .hero .tagline {
        font-size: 1rem;
    }

    .nav-links {
        gap: 1rem;
        font-size: 0.9rem;
    }

    .projects-grid,
    .skills-grid {
        grid-template-columns: 1fr;
    }

    .cta-buttons {
        flex-direction: column;
    }

    .btn {
        width: 100%;
        text-align: center;
    }
}