:root {
    --primary-color: #000000;
    --secondary-color: #ffffff;
    --accent-color: #f0f0f0;
    --text-color: #333333;
    --background-color: #ffffff;
    --card-background: #f8f9fa;
    --border-color: #e0e0e0;
    --shadow-color: rgba(0, 0, 0, 0.1);
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-fast: all 0.15s cubic-bezier(0.4, 0, 0.2, 1);
}

[data-theme="dark"] {
    --primary-color: #ffffff;
    --secondary-color: #1a1a1a;
    --accent-color: #2a2a2a;
    --text-color: #e0e0e0;
    --background-color: #121212;
    --card-background: #1e1e1e;
    --border-color: #404040;
    --shadow-color: rgba(0, 0, 0, 0.3);
}

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

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--background-color);
    margin: 0;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    transition: var(--transition);
}

/* Dark mode toggle */
.theme-toggle {
    background: none;
    border: 2px solid var(--primary-color);
    color: var(--primary-color);
    border-radius: 50%;
    width: 40px;
    height: 40px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.2rem;
    transition: var(--transition);
    margin-left: 1rem;
}

.theme-toggle:hover {
    background-color: var(--primary-color);
    color: var(--secondary-color);
    transform: scale(1.1);
}

.theme-toggle:active {
    transform: scale(0.95);
}

.header {
    padding: 1rem 2rem;
    background-color: var(--secondary-color);
    display: flex;
    justify-content: space-between;
    align-items: center;
    position: sticky;
    top: 0;
    z-index: 1000;
    box-shadow: 0 2px 20px var(--shadow-color);
    backdrop-filter: blur(10px);
    transition: var(--transition);
}

.header h1 {
    color: var(--primary-color);
    font-size: 1.5rem;
    font-weight: 700;
    text-decoration: none;
    transition: var(--transition);
    margin: 0;
}

.header h1:hover {
    transform: translateY(-2px);
    text-shadow: 0 2px 8px var(--shadow-color);
}

.topnav {
    display: flex;
    gap: 1rem;
    align-items: center;
}

.topnav a {
    color: var(--primary-color);
    text-decoration: none;
    font-size: 1rem;
    font-weight: 500;
    padding: 0.5rem 1rem;
    border-radius: 8px;
    transition: var(--transition);
    position: relative;
    overflow: hidden;
}

.topnav a::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.2), transparent);
    transition: var(--transition);
}

.topnav a:hover::before {
    left: 100%;
}

.topnav a:hover, .topnav a.active {
    background-color: var(--primary-color);
    color: var(--secondary-color);
    transform: translateY(-2px);
    box-shadow: 0 4px 12px var(--shadow-color);
}

/* Mobile Navigation */
.mobile-nav-toggle {
    display: none;
    background: none;
    border: none;
    color: var(--primary-color);
    font-size: 1.5rem;
    cursor: pointer;
    padding: 0.5rem;
    transition: var(--transition);
}

.mobile-nav-toggle:hover {
    opacity: 0.8;
    transform: scale(1.1);
}

.main {
    max-width: 1200px;
    margin: 0 auto;
    padding: 2rem;
    text-align: center;
    animation: fadeInUp 0.8s ease-out;
}

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

.main h2 {
    font-size: 2.5rem;
    margin-bottom: 1.5rem;
    color: var(--primary-color);
    background: linear-gradient(135deg, var(--primary-color), #666);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    animation: slideInLeft 0.8s ease-out;
}

@keyframes slideInLeft {
    from {
        opacity: 0;
        transform: translateX(-30px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

.main p {
    font-size: 1.25rem;
    line-height: 1.8;
    margin: 1rem auto;
    max-width: 800px;
    animation: fadeIn 1s ease-out 0.2s both;
}

@keyframes fadeIn {
    from {
        opacity: 0;
    }
    to {
        opacity: 1;
    }
}

.profileimg {
    width: 300px;
    height: 300px;
    border-radius: 50%;
    object-fit: cover;
    object-position: 50% 10%;
    margin: 2rem auto;
    box-shadow: 0 8px 32px var(--shadow-color);
    transition: var(--transition);
    animation: scaleIn 0.8s ease-out 0.4s both;
    border: 4px solid var(--card-background);
}

@keyframes scaleIn {
    from {
        opacity: 0;
        transform: scale(0.8);
    }
    to {
        opacity: 1;
        transform: scale(1);
    }
}

.profileimg:hover {
    transform: scale(1.05) rotate(2deg);
    box-shadow: 0 12px 40px var(--shadow-color);
}

blockquote {
    background: var(--card-background);
    border-left: 4px solid var(--primary-color);
    padding: 1.5rem;
    margin: 2rem auto;
    max-width: 600px;
    border-radius: 8px;
    box-shadow: 0 4px 16px var(--shadow-color);
    transition: var(--transition);
    animation: slideInRight 0.8s ease-out 0.6s both;
}

@keyframes slideInRight {
    from {
        opacity: 0;
        transform: translateX(30px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

blockquote:hover {
    transform: translateY(-4px);
    box-shadow: 0 8px 24px var(--shadow-color);
}

blockquote p {
    font-size: 1.2rem;
    font-style: italic;
    margin-bottom: 0.5rem;
    color: var(--text-color);
}

blockquote cite {
    font-size: 0.9rem;
    color: var(--primary-color);
    font-weight: 500;
}

.main2 {
    max-width: 1200px;
    margin: 0 auto;
    padding: 2rem;
    animation: fadeInUp 0.8s ease-out;
}

.main2 h2 {
    font-size: 2rem;
    margin-bottom: 1.5rem;
    color: var(--primary-color);
    background: linear-gradient(135deg, var(--primary-color), #666);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.main2 h3 {
    font-size: 1.5rem;
    margin-bottom: 1rem;
    color: var(--text-color);
}

.main2 .p1 {
    font-size: 1.25rem;
    font-weight: 600;
    margin: 1.5rem 0;
}

.main2 .p2 {
    font-size: 1.1rem;
    margin: 1rem 0;
}

.footer {
    background-color: var(--secondary-color);
    color: var(--primary-color);
    text-align: center;
    padding: 1rem;
    margin-top: auto;
    box-shadow: 0 -2px 20px var(--shadow-color);
    transition: var(--transition);
}

.footer-content {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.25rem;
}

.footer p {
    margin: 0;
}

.phone-link {
    color: var(--primary-color);
    text-decoration: none;
    transition: var(--transition);
    padding: 0.5rem 1rem;
    border-radius: 4px;
}

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

/* About Page Styles */
.resume-links {
    display: flex;
    gap: 1rem;
    justify-content: center;
    margin: 2rem 0;
    animation: fadeInUp 0.8s ease-out 0.2s both;
}

.resume-link {
    display: inline-block;
    padding: 0.75rem 1.5rem;
    background: linear-gradient(135deg, var(--primary-color), #666);
    color: var(--secondary-color);
    text-decoration: none;
    border-radius: 8px;
    font-weight: 500;
    transition: var(--transition);
    position: relative;
    overflow: hidden;
}

.resume-link::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.2), transparent);
    transition: var(--transition);
}

.resume-link:hover::before {
    left: 100%;
}

.resume-link:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 24px var(--shadow-color);
}

.about-section {
    max-width: 800px;
    margin: 3rem auto;
    padding: 2rem;
    background: var(--card-background);
    border-radius: 12px;
    box-shadow: 0 4px 16px var(--shadow-color);
    transition: var(--transition);
    animation: fadeInUp 0.8s ease-out;
}

.about-section:hover {
    transform: translateY(-4px);
    box-shadow: 0 8px 32px var(--shadow-color);
}

.about-section h3 {
    color: var(--primary-color);
    font-size: 1.75rem;
    margin-bottom: 1.5rem;
    position: relative;
    padding-bottom: 0.5rem;
}

.about-section h3::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 60px;
    height: 3px;
    background: linear-gradient(90deg, var(--primary-color), #666);
    border-radius: 2px;
    transition: var(--transition);
}

.about-section:hover h3::after {
    width: 100px;
}

.about-section p {
    font-size: 1.1rem;
    line-height: 1.8;
    margin-bottom: 1.5rem;
}

.courses-link {
    display: inline-block;
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 500;
    margin-top: 1rem;
    transition: var(--transition);
    padding: 0.5rem 1rem;
    border-radius: 6px;
}

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

.experience-item {
    background: var(--card-background);
    padding: 1.5rem;
    border-radius: 12px;
    margin: 1rem 0;
    box-shadow: 0 4px 16px var(--shadow-color);
    transition: var(--transition);
    border: 1px solid var(--border-color);
}

.experience-item:hover {
    transform: translateY(-4px);
    box-shadow: 0 8px 32px var(--shadow-color);
}

.experience-item h4 {
    color: var(--primary-color);
    font-size: 1.3rem;
    margin-bottom: 0.5rem;
}

.role, .duration, .location {
    color: var(--text-color);
    margin: 0.25rem 0;
}

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

.skill-category {
    background: var(--card-background);
    padding: 1.5rem;
    border-radius: 12px;
    box-shadow: 0 4px 16px var(--shadow-color);
    transition: var(--transition);
    border: 1px solid var(--border-color);
}

.skill-category:hover {
    transform: translateY(-4px);
    box-shadow: 0 8px 32px var(--shadow-color);
}

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

.skill-category ul {
    list-style: none;
    padding: 0;
}

.skill-category li {
    padding: 0.5rem 0;
    border-bottom: 1px solid var(--border-color);
    transition: var(--transition);
}

.skill-category li:last-child {
    border-bottom: none;
}

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

.skill-category a {
    color: var(--text-color);
    text-decoration: none;
    transition: var(--transition);
}

.skill-category a:hover {
    color: var(--primary-color);
    text-decoration: underline;
}

/* Loading animation for images */
.loading {
    opacity: 0;
    transition: opacity 0.3s ease;
}

.loaded {
    opacity: 1;
}

/* Lazy loading placeholder */
.lazy-placeholder {
    background: linear-gradient(90deg, var(--card-background) 25%, var(--border-color) 50%, var(--card-background) 75%);
    background-size: 200% 100%;
    animation: loading 1.5s infinite;
    border-radius: 8px;
}

@keyframes loading {
    0% {
        background-position: 200% 0;
    }
    100% {
        background-position: -200% 0;
    }
}

/* Performance optimizations */
img {
    max-width: 100%;
    height: auto;
}

/* Reduce motion for users who prefer it */
@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
        scroll-behavior: auto !important;
    }
}

/* Back to top button */
.back-to-top {
    position: fixed;
    bottom: 2rem;
    right: 2rem;
    background: var(--primary-color);
    color: var(--secondary-color);
    border: none;
    border-radius: 50%;
    width: 50px;
    height: 50px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.2rem;
    box-shadow: 0 4px 16px var(--shadow-color);
    transition: var(--transition);
    opacity: 0;
    visibility: hidden;
    transform: translateY(20px);
}

.back-to-top.visible {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.back-to-top:hover {
    transform: translateY(-4px);
    box-shadow: 0 8px 24px var(--shadow-color);
}

/* Responsive Design */
@media (max-width: 768px) {
    .resume-links {
        flex-direction: column;
        align-items: center;
    }

    .about-section {
        margin: 2rem 1rem;
        padding: 1.5rem;
    }

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

    .theme-toggle {
        width: 35px;
        height: 35px;
        font-size: 1rem;
    }
}

@media (max-width: 768px) {
    .header {
        padding: 1rem;
    }

    .header h1 {
        font-size: 1.3rem;
    }

    .mobile-nav-toggle {
        display: block;
    }

    .topnav {
        position: fixed;
        top: 100%;
        left: 0;
        width: 100%;
        background-color: var(--secondary-color);
        flex-direction: column;
        padding: 1rem;
        box-shadow: 0 4px 16px var(--shadow-color);
        transform: translateY(-100%);
        opacity: 0;
        visibility: hidden;
        transition: var(--transition);
    }

    .topnav.active {
        transform: translateY(0);
        opacity: 1;
        visibility: visible;
    }

    .topnav a {
        width: 100%;
        text-align: center;
        padding: 1rem;
        border-radius: 8px;
        margin: 0.25rem 0;
    }

    .topnav a:last-child {
        margin-bottom: 0;
    }

    .main {
        padding: 1rem;
    }

    .main h2 {
        font-size: 2rem;
    }

    .main p {
        font-size: 1.1rem;
    }

    .profileimg {
        width: 250px;
        height: 250px;
    }
}

@media (max-width: 480px) {
    .main h2 {
        font-size: 1.8rem;
    }

    .profileimg {
        width: 200px;
        height: 200px;
    }

    .back-to-top {
        bottom: 1rem;
        right: 1rem;
        width: 45px;
        height: 45px;
    }
}

/* Contact page specific styles */
.contact-intro {
    max-width: 600px;
    margin: 0 auto 2rem;
    font-size: 1.1rem;
    line-height: 1.7;
}

.contact-form {
    max-width: 800px;
    margin: 0 auto;
    background: var(--card-background);
    border-radius: 12px;
    padding: 2rem;
    box-shadow: 0 4px 16px var(--shadow-color);
    transition: var(--transition);
}

.contact-form:hover {
    transform: translateY(-4px);
    box-shadow: 0 8px 32px var(--shadow-color);
}

.contact-form iframe {
    border-radius: 8px;
    border: 1px solid var(--border-color);
}

.contact-info {
    margin-top: 3rem;
    text-align: center;
}

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

.social-links {
    display: flex;
    justify-content: center;
    gap: 1rem;
    margin-top: 1rem;
}

.social-link {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.75rem 1rem;
    background: var(--card-background);
    color: var(--text-color);
    text-decoration: none;
    border-radius: 8px;
    transition: var(--transition);
    border: 1px solid var(--border-color);
}

.social-link:hover {
    background: var(--primary-color);
    color: var(--secondary-color);
    transform: translateY(-2px);
    box-shadow: 0 4px 16px var(--shadow-color);
}

.social-icon {
    font-size: 1.2rem;
}

.social-text {
    font-weight: 500;
}

/* Courses page specific styles */
.courses-intro {
    max-width: 700px;
    margin: 0 auto 3rem;
    font-size: 1.1rem;
    line-height: 1.7;
    color: var(--text-color);
}

/* Certifications page specific styles */
.certifications-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: 2rem;
    margin-top: 1.5rem;
}

.cert-card {
    background: var(--card-background);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    box-shadow: 0 4px 16px var(--shadow-color);
    padding: 1rem;
    transition: var(--transition);
}

.cert-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 8px 24px var(--shadow-color);
}

.cert-embed {
    width: 100%;
    min-height: 320px;
    border: none;
    border-radius: 8px;
}

@media (max-width: 768px) {
    .cert-embed {
        min-height: 280px;
    }
}

.courses-container {
    max-width: 1000px;
    margin: 0 auto;
}

.institution-section {
    background: var(--card-background);
    padding: 2rem;
    border-radius: 12px;
    margin: 2rem 0;
    box-shadow: 0 4px 16px var(--shadow-color);
    transition: var(--transition);
    border: 1px solid var(--border-color);
}

.institution-section:hover {
    transform: translateY(-4px);
    box-shadow: 0 8px 32px var(--shadow-color);
}

.institution-section h3 {
    color: var(--primary-color);
    font-size: 1.8rem;
    margin-bottom: 1.5rem;
    position: relative;
    padding-bottom: 0.5rem;
}

.institution-section h3::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 80px;
    height: 3px;
    background: linear-gradient(90deg, var(--primary-color), #666);
    border-radius: 2px;
    transition: var(--transition);
}

.institution-section:hover h3::after {
    width: 120px;
}

.course-category {
    margin: 1.5rem 0;
}

.course-category:last-child {
    margin-bottom: 0;
}

.course-category h4 {
    color: var(--primary-color);
    font-size: 1.3rem;
    margin-bottom: 1rem;
}

.course-list {
    list-style: none;
    padding: 0;
}

.course-list li {
    padding: 0.75rem 1rem;
    margin: 0.5rem 0;
    background: var(--background-color);
    border-radius: 8px;
    border: 1px solid var(--border-color);
    transition: var(--transition);
    cursor: pointer;
}

.course-list li:hover {
    background: var(--primary-color);
    color: var(--secondary-color);
    transform: translateX(8px);
    box-shadow: 0 4px 12px var(--shadow-color);
}

@media (max-width: 768px) {
    .institution-section {
        margin: 1rem 0;
        padding: 1.5rem;
    }

    .course-list li {
        font-size: 0.9rem;
        padding: 0.5rem 0.75rem;
    }
}

@media (max-width: 768px) {
    .footer-content {
        flex-direction: column;
        gap: 0.5rem;
    }
}