/* CSS Custom Properties for easy customization */
:root {
    --primary-color: #2563eb;
    --secondary-color: #64748b;
    --accent-color: #f59e0b;
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --background-primary: #ffffff;
    --background-secondary: #f8fafc;
    --border-color: #e2e8f0;
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    --border-radius: 8px;
    --transition: all 0.3s ease;
    --max-width: 1200px;
    --section-padding: 5rem 0;
}

/* Reset and Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    line-height: 1.6;
    color: var(--text-primary);
    background-color: var(--background-primary);
}

/* Container */
.container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 1rem;
}

/* Section */
.section {
    padding: var(--section-padding);
}

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

/* Header and Navigation */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background-color: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border-color);
    z-index: 1000;
}

.nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem;
    max-width: var(--max-width);
    margin: 0 auto;
}

.nav-brand h2 {
    color: var(--primary-color);
    font-weight: 700;
}

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

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

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

.nav-toggle {
    display: none;
    flex-direction: column;
    background: none;
    border: none;
    cursor: pointer;
    padding: 0.5rem;
}

.nav-toggle span {
    width: 25px;
    height: 3px;
    background-color: var(--text-primary);
    margin: 3px 0;
    transition: var(--transition);
}

/* About Section */
.about-section {
    padding-top: 8rem;
    background-color: var(--background-secondary);
}

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

.about-title {
    font-size: 3rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
}

.about-subtitle {
    font-size: 1.25rem;
    color: var(--primary-color);
    font-weight: 600;
    margin-bottom: 1.5rem;
}

.about-description {
    font-size: 1.1rem;
    color: var(--text-secondary);
    margin-bottom: 2rem;
    line-height: 1.7;
}

.about-buttons {
    display: flex;
    gap: 1rem;
}

.btn {
    display: inline-block;
    padding: 0.75rem 1.5rem;
    border-radius: var(--border-radius);
    text-decoration: none;
    font-weight: 600;
    transition: var(--transition);
    border: 2px solid transparent;
}

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

.btn-primary:hover {
    background-color: #1d4ed8;
    transform: translateY(-2px);
}

.btn-secondary {
    border-color: var(--primary-color);
    color: var(--primary-color);
}

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

.profile-photo {
    width: 100%;
    max-width: 300px;
    height: 300px;
    object-fit: cover;
    object-position: center bottom;
    border-radius: 50%;
    box-shadow: var(--shadow-lg);
    margin: 0 auto;
    display: block;
}

/* Skills Section */
.skills-section {
    background-color: var(--background-primary);
}

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

.skill-item {
    text-align: center;
    padding: 2rem;
    background-color: var(--background-secondary);
    border-radius: var(--border-radius);
    transition: var(--transition);
}

.skill-item:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

.skill-icon {
    font-size: 3rem;
    margin-bottom: 1rem;
}

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

.skill-item p {
    color: var(--text-secondary);
}

/* Projects Section */
.projects-section {
    background-color: var(--background-secondary);
}

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

.project-card {
    background-color: var(--background-primary);
    border-radius: var(--border-radius);
    overflow: hidden;
    box-shadow: var(--shadow);
    transition: var(--transition);
}

.project-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

.project-image img {
    width: 100%;
    height: 200px;
    object-fit: cover;
    object-position: center left;
}

.project-content {
    padding: 1.5rem;
}

.project-title {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
}

.project-description {
    color: var(--text-secondary);
    margin-bottom: 1rem;
    line-height: 1.6;
}

.project-tech {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin-bottom: 1rem;
}

.tech-tag {
    background-color: var(--primary-color);
    color: white;
    padding: 0.25rem 0.75rem;
    border-radius: 20px;
    font-size: 0.875rem;
    font-weight: 500;
}

.project-links {
    display: flex;
    gap: 1rem;
}

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

.project-link:hover {
    color: #1d4ed8;
}

/* Contact Section */
.contact-section {
    background-color: var(--background-primary);
    text-align: center;
}

.contact-description {
    font-size: 1.1rem;
    color: var(--text-secondary);
    margin-bottom: 2rem;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

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

.contact-link {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 1rem 1.5rem;
    background-color: var(--background-secondary);
    border-radius: var(--border-radius);
    text-decoration: none;
    color: var(--text-primary);
    font-weight: 600;
    transition: var(--transition);
}

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

.contact-icon {
    font-size: 1.25rem;
}

/* Footer */
.footer {
    background-color: var(--text-primary);
    color: white;
    text-align: center;
    padding: 2rem 0;
}

/* Responsive Design */
@media (max-width: 768px) {
    .nav-links {
        position: fixed;
        top: 100%;
        left: 0;
        right: 0;
        background-color: white;
        flex-direction: column;
        padding: 2rem;
        box-shadow: var(--shadow);
        transform: translateY(-100%);
        opacity: 0;
        visibility: hidden;
        transition: var(--transition);
    }

    .nav-links.active {
        transform: translateY(0);
        opacity: 1;
        visibility: visible;
    }

    .nav-toggle {
        display: flex;
    }

    .about-content {
        grid-template-columns: 1fr;
        text-align: center;
        gap: 2rem;
    }

    .about-title {
        font-size: 2.5rem;
    }

    .section-title {
        font-size: 2rem;
    }

    .about-buttons {
        justify-content: center;
        flex-wrap: wrap;
    }

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

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

    .contact-links {
        flex-direction: column;
        align-items: center;
    }

    .contact-link {
        width: 100%;
        max-width: 300px;
        justify-content: center;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 0.5rem;
    }

    .about-title {
        font-size: 2rem;
    }

    .section-title {
        font-size: 1.75rem;
    }

    .btn {
        padding: 0.5rem 1rem;
        font-size: 0.9rem;
    }
}