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

:root {
    --primary-color: #2563eb;
    --secondary-color: #1e40af;
    --text-dark: #1f2937;
    --text-light: #6b7280;
    --bg-light: #f9fafb;
    --card-bg: #ffffff;
    --accent: #3b82f6;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    color: var(--text-dark);
    background: var(--bg-light);
}

/* Navigation */
nav {
    background: var(--card-bg);
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
    position: fixed;
    width: 100%;
    top: 0;
    z-index: 1000;
    transition: all 0.3s ease;
}

nav.scrolled {
    box-shadow: 0 4px 20px rgba(0,0,0,0.15);
}

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

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

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

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

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

.menu-toggle {
    display: none;
    flex-direction: column;
    cursor: pointer;
    gap: 5px;
}

.menu-toggle span {
    width: 25px;
    height: 3px;
    background: var(--text-dark);
    transition: all 0.3s;
}

/* Hero Section */
.hero {
    margin-top: 80px;
    padding: 4rem 2rem;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    text-align: center;
}

.hero-content {
    max-width: 800px;
    margin: 0 auto;
}

.hero h1 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
    animation: fadeInUp 0.8s ease;
}

.hero .subtitle {
    font-size: 1.2rem;
    margin-bottom: 1rem;
    opacity: 0.95;
    animation: fadeInUp 0.8s ease 0.2s backwards;
}

.hero p {
    font-size: 1.1rem;
    line-height: 1.8;
    opacity: 0.9;
    animation: fadeInUp 0.8s ease 0.4s backwards;
}

.cta-buttons {
    margin-top: 2rem;
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
    animation: fadeInUp 0.8s ease 0.6s backwards;
}

.btn {
    padding: 0.8rem 2rem;
    border: none;
    border-radius: 5px;
    font-size: 1rem;
    cursor: pointer;
    transition: all 0.3s;
    text-decoration: none;
    display: inline-block;
}

.btn-primary {
    background: white;
    color: var(--primary-color);
    font-weight: 600;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(0,0,0,0.2);
}

.btn-secondary {
    background: transparent;
    color: white;
    border: 2px solid white;
    font-weight: 600;
}

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

/* Container */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 4rem 2rem;
}

/* Section Styles */
section {
    margin-bottom: 4rem;
}

.section-title {
    font-size: 2rem;
    margin-bottom: 2rem;
    color: var(--text-dark);
    position: relative;
    padding-bottom: 0.5rem;
}

.section-title::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 60px;
    height: 4px;
    background: var(--primary-color);
}

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

.skill-card {
    background: var(--card-bg);
    padding: 2rem;
    border-radius: 10px;
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
    transition: transform 0.3s, box-shadow 0.3s;
}

.skill-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 15px rgba(0,0,0,0.15);
}

.skill-card h3 {
    color: var(--primary-color);
    margin-bottom: 1rem;
    font-size: 1.3rem;
}

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

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

.skill-card li::before {
    content: '▹ ';
    color: var(--primary-color);
    font-weight: bold;
}

/* Experience & Education */
.timeline {
    position: relative;
    padding-left: 2rem;
}

.timeline::before {
    content: '';
    position: absolute;
    left: 0;
    top: 0;
    bottom: 0;
    width: 2px;
    background: var(--primary-color);
}

.timeline-item {
    background: var(--card-bg);
    padding: 1.5rem;
    border-radius: 10px;
    margin-bottom: 1.5rem;
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
    position: relative;
}

.timeline-item::before {
    content: '';
    position: absolute;
    left: -2.5rem;
    top: 1.5rem;
    width: 12px;
    height: 12px;
    background: var(--primary-color);
    border-radius: 50%;
    border: 3px solid var(--bg-light);
}

.timeline-item h3 {
    color: var(--primary-color);
    margin-bottom: 0.5rem;
}

.timeline-item .duration {
    color: var(--text-light);
    font-size: 0.9rem;
    font-style: italic;
}

/* Projects Section */
.project-card {
    background: var(--card-bg);
    border-radius: 10px;
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
    padding: 2rem;
    margin-bottom: 2rem;
    transition: transform 0.3s, box-shadow 0.3s;
}

.project-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 15px rgba(0,0,0,0.15);
}

.project-card h3 {
    color: var(--primary-color);
    margin-bottom: 1rem;
    font-size: 1.5rem;
}

.project-card p {
    color: var(--text-light);
    margin-bottom: 1rem;
    line-height: 1.8;
}

.project-link {
    color: var(--accent);
    text-decoration: none;
    font-weight: 600;
}

.project-link:hover {
    text-decoration: underline;
}

/* Contact Section */
.contact-info {
    background: var(--card-bg);
    padding: 2rem;
    border-radius: 10px;
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
}

.contact-item {
    display: flex;
    align-items: center;
    gap: 1rem;
    margin-bottom: 1.5rem;
    color: var(--text-dark);
}

.contact-item svg {
    width: 24px;
    height: 24px;
    color: var(--primary-color);
}

/* Footer */
footer {
    background: var(--text-dark);
    color: white;
    text-align: center;
    padding: 2rem;
    margin-top: 4rem;
}

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

/* Responsive Design */
@media (max-width: 768px) {
    .menu-toggle {
        display: flex;
    }

    .nav-links {
        position: fixed;
        top: 70px;
        right: -100%;
        flex-direction: column;
        background: var(--card-bg);
        width: 100%;
        padding: 2rem;
        box-shadow: 0 4px 10px rgba(0,0,0,0.1);
        transition: right 0.3s;
    }

    .nav-links.active {
        right: 0;
    }

    .hero h1 {
        font-size: 2rem;
    }

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

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

    .cta-buttons {
        flex-direction: column;
        align-items: center;
    }

    .btn {
        width: 100%;
        max-width: 300px;
    }

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

    .timeline {
        padding-left: 1.5rem;
    }

    .timeline-item::before {
        left: -2rem;
    }

    .section-title {
        font-size: 1.5rem;
    }
}

@media (max-width: 480px) {
    .nav-container {
        padding: 1rem;
    }

    .hero {
        padding: 3rem 1rem;
    }

    .container {
        padding: 2rem 1rem;
    }
}