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

:root {
    --primary-color: #FF9900;
    --secondary-color: #232F3E;
    --accent-color: #146EB4;
    --text-primary: #232F3E;
    --text-secondary: #545B64;
    --text-light: #687078;
    --bg-primary: #FFFFFF;
    --bg-secondary: #F9FAFB;
    --bg-dark: #232F3E;
    --border-color: #E5E7EB;
    --shadow-sm: 0 1px 3px 0 rgba(0, 0, 0, 0.1);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    --transition: all 0.3s ease;
}

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

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

/* Navbar */
.navbar {
    background-color: var(--bg-primary);
    box-shadow: var(--shadow-sm);
    position: sticky;
    top: 0;
    z-index: 1000;
    border-bottom: 1px solid var(--border-color);
}

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

.nav-brand {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--secondary-color);
}

.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);
    position: relative;
}

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

.nav-links a::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background-color: var(--primary-color);
    transition: var(--transition);
}

.nav-links a:hover::after,
.nav-links a.active::after {
    width: 100%;
}

.mobile-menu-toggle {
    display: none;
    flex-direction: column;
    background: none;
    border: none;
    cursor: pointer;
    padding: 0;
}

.mobile-menu-toggle span {
    width: 25px;
    height: 3px;
    background-color: var(--secondary-color);
    margin: 3px 0;
    transition: var(--transition);
}

/* Hero Section */
.hero {
    background: linear-gradient(135deg, var(--secondary-color) 0%, #1a252f 100%);
    color: white;
    padding: 6rem 0;
    text-align: center;
}

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

.hero-title {
    font-size: 3rem;
    font-weight: 700;
    margin-bottom: 1rem;
    line-height: 1.2;
}

.hero-subtitle {
    font-size: 1.5rem;
    font-weight: 500;
    color: var(--primary-color);
    margin-bottom: 1rem;
}

.hero-description {
    font-size: 1.125rem;
    color: rgba(255, 255, 255, 0.9);
    margin-bottom: 2rem;
}

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

.btn {
    display: inline-block;
    padding: 0.875rem 2rem;
    border-radius: 6px;
    text-decoration: none;
    font-weight: 600;
    transition: var(--transition);
    border: 2px solid transparent;
}

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

.btn-primary:hover {
    background-color: #FF8800;
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

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

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

/* Sections */
.section {
    padding: 5rem 0;
}

.section:nth-child(even) {
    background-color: var(--bg-secondary);
}

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

/* About Section */
.about-content {
    max-width: 800px;
    margin: 0 auto;
    font-size: 1.125rem;
    line-height: 1.8;
}

.about-content p {
    margin-bottom: 1.5rem;
}

/* Timeline */
.timeline {
    max-width: 800px;
    margin: 0 auto;
    position: relative;
    padding-left: 2rem;
}

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

.timeline-item {
    position: relative;
    margin-bottom: 2.5rem;
}

.timeline-marker {
    position: absolute;
    left: -2.5rem;
    top: 0;
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background-color: var(--primary-color);
    border: 3px solid var(--bg-primary);
}

.timeline-content h3 {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--secondary-color);
    margin-bottom: 0.5rem;
}

.timeline-content .company {
    font-weight: 600;
    color: var(--accent-color);
    margin-bottom: 0.25rem;
}

.timeline-content .period {
    color: var(--text-light);
    font-size: 0.875rem;
}

.timeline-content .description {
    color: var(--text-secondary);
    font-size: 0.875rem;
    margin-top: 0.5rem;
    font-style: italic;
}

/* Education Grid */
.education-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2rem;
    max-width: 1000px;
    margin: 0 auto;
}

.education-card {
    background-color: var(--bg-primary);
    padding: 2rem;
    border-radius: 8px;
    box-shadow: var(--shadow-md);
    transition: var(--transition);
    border: 1px solid var(--border-color);
}

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

.education-card h3 {
    font-size: 1.25rem;
    color: var(--secondary-color);
    margin-bottom: 0.75rem;
}

.education-card .institution {
    font-weight: 600;
    color: var(--accent-color);
    margin-bottom: 0.5rem;
}

.education-card .period {
    color: var(--text-light);
    font-size: 0.875rem;
}

/* Skills Section */
.skills-content {
    max-width: 1000px;
    margin: 0 auto;
    display: grid;
    gap: 3rem;
}

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

.skill-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.75rem;
}

.skill-tag {
    background-color: var(--primary-color);
    color: var(--secondary-color);
    padding: 0.5rem 1.25rem;
    border-radius: 20px;
    font-weight: 500;
    font-size: 0.875rem;
}

.certification-list {
    display: grid;
    gap: 1rem;
}

.cert-item {
    background-color: var(--bg-primary);
    padding: 1rem 1.5rem;
    border-radius: 6px;
    border-left: 4px solid var(--accent-color);
    font-weight: 500;
}

.language-list {
    display: grid;
    gap: 1rem;
}

.language-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    background-color: var(--bg-primary);
    padding: 1rem 1.5rem;
    border-radius: 6px;
    border: 1px solid var(--border-color);
}

.language-name {
    font-weight: 600;
    color: var(--secondary-color);
}

.language-level {
    color: var(--text-light);
    font-size: 0.875rem;
}

/* Certifications Banner */
.certifications-banner {
    background: linear-gradient(135deg, #232F3E 0%, #1a252f 100%);
    padding: 2rem 0;
    text-align: center;
}

.cert-banner-title {
    color: var(--primary-color);
    font-size: 1rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    margin-bottom: 1rem;
}

.cert-badges {
    display: flex;
    flex-wrap: wrap;
    gap: 1rem;
    justify-content: center;
    align-items: center;
}

.cert-badge {
    background-color: rgba(255, 255, 255, 0.1);
    color: white;
    padding: 0.5rem 1.25rem;
    border-radius: 20px;
    font-size: 0.875rem;
    font-weight: 500;
    border: 1px solid rgba(255, 153, 0, 0.3);
    transition: var(--transition);
}

.cert-badge:hover {
    background-color: rgba(255, 153, 0, 0.2);
    border-color: var(--primary-color);
    transform: translateY(-2px);
}

/* Contact Section */
.contact-content {
    max-width: 600px;
    margin: 0 auto;
    text-align: center;
}

.contact-content p {
    font-size: 1.125rem;
    margin-bottom: 2rem;
}

.contact-links {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.contact-link {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.75rem;
    padding: 1rem 2rem;
    background-color: var(--bg-primary);
    border: 2px solid var(--border-color);
    border-radius: 8px;
    text-decoration: none;
    color: var(--secondary-color);
    font-weight: 500;
    transition: var(--transition);
}

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

.contact-link svg {
    flex-shrink: 0;
}

/* Contact Form */
.contact-form {
    max-width: 600px;
    margin: 0 auto 2rem;
}

.form-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1rem;
}

.form-group {
    margin-bottom: 1rem;
}

.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 600;
    color: var(--secondary-color);
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 0.75rem 1rem;
    border: 2px solid var(--border-color);
    border-radius: 6px;
    font-family: inherit;
    font-size: 0.95rem;
    transition: var(--transition);
    background-color: var(--bg-primary);
}

.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(255, 153, 0, 0.1);
}

.form-group textarea {
    resize: vertical;
    min-height: 100px;
}

.btn-submit {
    width: 100%;
    cursor: pointer;
    border: none;
    font-size: 1rem;
    position: relative;
}

.btn-submit:disabled {
    opacity: 0.6;
    cursor: not-allowed;
}

.form-status {
    margin-top: 1rem;
    padding: 1rem;
    border-radius: 6px;
    text-align: center;
    font-weight: 500;
    display: none;
}

.form-status.success {
    display: block;
    background-color: #d4edda;
    color: #155724;
    border: 1px solid #c3e6cb;
}

.form-status.error {
    display: block;
    background-color: #f8d7da;
    color: #721c24;
    border: 1px solid #f5c6cb;
}

.contact-links {
    margin-top: 2rem;
}

/* Blog Styles */
.page-header {
    background: linear-gradient(135deg, var(--secondary-color) 0%, #1a252f 100%);
    color: white;
    padding: 4rem 0;
    text-align: center;
}

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

.page-header p {
    font-size: 1.25rem;
    color: rgba(255, 255, 255, 0.9);
}

.blog-section {
    min-height: 400px;
}

.blog-grid {
    display: flex;
    flex-direction: column;
    gap: 2rem;
    max-width: 900px;
    margin: 0 auto;
}

.blog-card {
    background: var(--bg-primary);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 1.5rem;
    box-shadow: var(--shadow-md);
    transition: var(--transition);
}

.blog-card:hover {
    box-shadow: var(--shadow-lg);
    transform: translateY(-3px);
}

.blog-header-row {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 12px;
}

.blog-cat-badge {
    background: var(--accent-color);
    color: white;
    padding: 4px 12px;
    border-radius: 4px;
    font-size: 0.7rem;
    font-weight: 600;
    text-transform: uppercase;
}

.blog-post-date {
    color: var(--text-light);
    font-size: 0.85rem;
}

.blog-post-title {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--secondary-color);
    line-height: 1.4;
    margin-bottom: 12px;
}

.blog-content-wrapper {
    margin-bottom: 12px;
}

.blog-info-block {
    margin-bottom: 10px;
    line-height: 1.6;
}

.blog-label {
    color: var(--primary-color);
    font-size: 0.85rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.3px;
}

.blog-description {
    color: var(--text-secondary);
    font-size: 0.9rem;
}

.blog-tech-row {
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
    padding-top: 12px;
    margin-top: 12px;
    margin-bottom: 12px;
    border-top: 1px solid var(--border-color);
}

.tech-pill {
    background: var(--bg-secondary);
    color: var(--accent-color);
    padding: 4px 10px;
    border-radius: 12px;
    font-size: 0.7rem;
    font-weight: 600;
    border: 1px solid var(--border-color);
}

.blog-read-link {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 600;
    font-size: 0.9rem;
    transition: var(--transition);
}

.blog-read-link:hover {
    gap: 10px;
}

.loading,
.no-posts {
    text-align: center;
    padding: 3rem;
    color: var(--text-secondary);
    font-size: 1.125rem;
}

/* Publications Styles */
.publications-section {
    background-color: var(--bg-primary);
}

.publications-stats {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1.5rem;
    margin-bottom: 3rem;
    max-width: 800px;
    margin-left: auto;
    margin-right: auto;
}

.stat-card {
    background-color: var(--bg-secondary);
    padding: 1.5rem;
    border-radius: 8px;
    text-align: center;
    border: 1px solid var(--border-color);
}

.stat-number {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--primary-color);
    margin-bottom: 0.5rem;
}

.stat-label {
    font-size: 0.875rem;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.publications-list {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
    max-width: 900px;
    margin: 0 auto;
}

.publication-card {
    background-color: var(--bg-primary);
    border-radius: 8px;
    padding: 1.5rem;
    border: 1px solid var(--border-color);
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
}

.publication-card:hover {
    box-shadow: var(--shadow-md);
    border-color: var(--primary-color);
}

.pub-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 0.75rem;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.pub-year {
    font-weight: 600;
    color: var(--accent-color);
    font-size: 0.875rem;
}

.citation-badge {
    background-color: var(--bg-secondary);
    color: var(--text-secondary);
    padding: 0.25rem 0.75rem;
    border-radius: 12px;
    font-size: 0.75rem;
    font-weight: 500;
    border: 1px solid var(--border-color);
}

.pub-title {
    font-size: 1.125rem;
    font-weight: 600;
    color: var(--secondary-color);
    margin-bottom: 0.5rem;
    line-height: 1.4;
}

.pub-authors {
    color: var(--text-secondary);
    font-size: 0.875rem;
    margin-bottom: 0.25rem;
}

.pub-venue {
    color: var(--text-light);
    font-size: 0.875rem;
    font-style: italic;
    margin-bottom: 0.75rem;
}

.pub-link {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--primary-color);
    text-decoration: none;
    font-size: 0.875rem;
    font-weight: 600;
    transition: var(--transition);
}

.pub-link:hover {
    gap: 0.75rem;
}

.pub-link svg {
    width: 14px;
    height: 14px;
}

/* Footer */
.footer {
    background-color: var(--bg-dark);
    color: white;
    text-align: center;
    padding: 2rem 0;
    margin-top: 4rem;
}

/* Responsive Design */
@media (max-width: 768px) {
    .nav-links {
        position: fixed;
        top: 65px;
        left: -100%;
        flex-direction: column;
        background-color: var(--bg-primary);
        width: 100%;
        padding: 2rem;
        box-shadow: var(--shadow-lg);
        transition: var(--transition);
        gap: 1rem;
    }

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

    .mobile-menu-toggle {
        display: flex;
    }

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

    .hero-subtitle {
        font-size: 1.25rem;
    }

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

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

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

    .blog-grid {
        gap: 1.5rem;
    }

    .blog-card {
        padding: 1.25rem;
    }

    .blog-post-title {
        font-size: 1.1rem;
    }

    .blog-label {
        font-size: 0.8rem;
    }

    .blog-description {
        font-size: 0.85rem;
    }

    .timeline {
        padding-left: 1.5rem;
    }

    .timeline-marker {
        left: -2rem;
    }

    .form-row {
        grid-template-columns: 1fr;
        gap: 0;
    }

    .cert-badges {
        gap: 0.75rem;
    }

    .cert-badge {
        font-size: 0.8rem;
        padding: 0.4rem 1rem;
    }

    .publications-stats {
        grid-template-columns: 1fr;
        gap: 1rem;
    }

    .stat-card {
        padding: 1.25rem;
    }

    .stat-number {
        font-size: 2rem;
    }
}

@media (max-width: 480px) {
    .hero-title {
        font-size: 1.75rem;
    }

    .section {
        padding: 3rem 0;
    }

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