:root {
    --primary-color: #2c3e50;
    --secondary-color: #3498db;
    --accent-color: #e74c3c;
    --text-color: #333;
    --light-bg: #f8f9fa;
    --white: #ffffff;
    --border-color: #e0e0e0;
    --shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}

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

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

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

/* Header & Navigation */
header {
    background: var(--white);
    box-shadow: var(--shadow);
    position: sticky;
    top: 0;
    z-index: 100;
}

nav {
    padding: 1rem 0;
}

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

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

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

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

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

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

.hero h2 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

.tagline {
    font-size: 1.2rem;
    opacity: 0.9;
}

/* Sections */
.section {
    padding: 4rem 0;
}

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

.section h2 {
    font-size: 2rem;
    color: var(--primary-color);
    margin-bottom: 2rem;
    text-align: center;
}

/* About Section */
.about-content p {
    font-size: 1.1rem;
    margin-bottom: 1.5rem;
    max-width: 800px;
    margin-left: auto;
    margin-right: auto;
}

/* Professional Section */
.experience-timeline {
    margin-bottom: 3rem;
}

.experience-item {
    margin-bottom: 2.5rem;
    padding-bottom: 2.5rem;
    border-bottom: 1px solid var(--border-color);
}

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

.experience-item h3 {
    color: var(--primary-color);
    font-size: 1.4rem;
    margin-bottom: 0.5rem;
}

.company {
    font-weight: 600;
    color: var(--secondary-color);
    font-size: 1.1rem;
}

.period {
    color: #666;
    margin-bottom: 1rem;
    font-size: 0.95rem;
}

.experience-item ul {
    list-style-position: outside;
    margin-left: 1.5rem;
    margin-top: 1rem;
}

.experience-item li {
    margin-bottom: 0.75rem;
    line-height: 1.6;
}

.experience-summary {
    line-height: 1.8;
}

.experience-summary strong {
    color: var(--primary-color);
}

.education-section {
    margin-top: 3rem;
    padding-top: 2rem;
    border-top: 2px solid var(--border-color);
    text-align: center;
}

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

.education-section p {
    margin-bottom: 0.5rem;
}

.certifications {
    color: #666;
    font-size: 0.95rem;
}

.skills-section {
    margin-top: 2rem;
}

.skills-section h3 {
    color: var(--primary-color);
    font-size: 1.5rem;
    margin-bottom: 1.5rem;
}

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

.skill-category h4 {
    color: var(--secondary-color);
    margin-bottom: 1rem;
    font-size: 1.2rem;
}

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

.skill-category li {
    padding: 0.3rem 0;
    padding-left: 1.5rem;
    position: relative;
}

.skill-category li::before {
    content: "▹";
    position: absolute;
    left: 0;
    color: var(--secondary-color);
}

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

.project-card {
    background: var(--white);
    padding: 2rem;
    border-radius: 8px;
    box-shadow: var(--shadow);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.project-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.15);
}

.highlight-card {
    border-top: 4px solid var(--secondary-color);
}

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

.project-card p {
    margin-bottom: 1rem;
}

.project-card ul {
    margin: 1rem 0;
    margin-left: 1.5rem;
}

.project-card li {
    margin-bottom: 0.5rem;
}

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

/* Contact Section */
.contact-content {
    max-width: 800px;
    margin: 0 auto;
}

.contact-content > p {
    text-align: center;
    font-size: 1.1rem;
    margin-bottom: 2rem;
}

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

.contact-item {
    text-align: center;
}

.contact-item h3 {
    color: var(--primary-color);
    margin-bottom: 0.5rem;
    font-size: 1.2rem;
}

.contact-item a {
    color: var(--secondary-color);
    text-decoration: none;
    font-weight: 500;
}

.contact-item a:hover {
    text-decoration: underline;
}

.social-links {
    display: flex;
    justify-content: center;
    gap: 1.5rem;
    flex-wrap: wrap;
    margin-top: 2rem;
    padding-top: 2rem;
    border-top: 1px solid var(--border-color);
}

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

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

/* Buttons */
.btn {
    display: inline-block;
    padding: 0.75rem 1.5rem;
    background: var(--secondary-color);
    color: var(--white);
    text-decoration: none;
    border-radius: 4px;
    font-weight: 500;
    transition: background 0.3s ease, transform 0.2s ease;
}

.btn:hover {
    background: #2980b9;
    transform: translateY(-2px);
}

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

/* Responsive Design */
@media (max-width: 768px) {
    .nav-links {
        gap: 1rem;
        font-size: 0.9rem;
    }

    .hero h2 {
        font-size: 1.8rem;
    }

    .tagline {
        font-size: 1rem;
    }

    .section h2 {
        font-size: 1.5rem;
    }

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

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

@media (max-width: 480px) {
    .nav-links {
        flex-direction: column;
        gap: 0.5rem;
    }

    nav .container {
        flex-direction: column;
        gap: 1rem;
    }
}