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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    line-height: 1.6;
    color: #333;
    background-color: #ffffff;
    overflow-x: hidden;
}

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

/* Typography */
h1, h2, h3, h4, h5, h6 {
    font-weight: 600;
    line-height: 1.2;
    margin-bottom: 1rem;
}

p {
    margin-bottom: 1rem;
    color: #666;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 12px 24px;
    border: none;
    border-radius: 8px;
    text-decoration: none;
    font-weight: 500;
    font-size: 14px;
    transition: all 0.3s ease;
    cursor: pointer;
    position: relative;
    overflow: hidden;
}

.btn-primary {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 25px rgba(102, 126, 234, 0.3);
}

.btn-secondary {
    background: rgba(255, 255, 255, 0.15);
    color: white;
    border: 2px solid rgba(255, 255, 255, 0.3);
    backdrop-filter: blur(10px);
}

.btn-secondary:hover {
    background: rgba(255, 255, 255, 0.25);
    color: white;
    border-color: rgba(255, 255, 255, 0.5);
    transform: translateY(-2px);
    box-shadow: 0 10px 25px rgba(255, 255, 255, 0.2);
}

/* Navigation */
.navbar {
    position: fixed;
    top: 0;
    width: 100%;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid rgba(0, 0, 0, 0.1);
    z-index: 1000;
    transition: all 0.3s ease;
}

.navbar.scrolled {
    background: rgba(255, 255, 255, 0.98);
    box-shadow: 0 2px 20px rgba(0, 0, 0, 0.1);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 70px;
}

.nav-logo a {
    font-size: 24px;
    font-weight: 700;
    color: #333;
    text-decoration: none;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.nav-menu {
    display: flex;
    align-items: center;
    gap: 2rem;
}

.nav-link {
    color: #333;
    text-decoration: none;
    font-weight: 500;
    font-size: 14px;
    transition: color 0.3s ease;
    position: relative;
}

.nav-link:hover {
    color: #667eea;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    transition: width 0.3s ease;
}

.nav-link:hover::after {
    width: 100%;
}

.cv-download {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white !important;
    padding: 8px 16px;
    border-radius: 6px;
    font-size: 13px;
}

.cv-download:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(102, 126, 234, 0.3);
}

.nav-toggle {
    display: none;
    flex-direction: column;
    cursor: pointer;
}

.bar {
    width: 25px;
    height: 3px;
    background: #333;
    margin: 3px 0;
    transition: 0.3s;
    border-radius: 2px;
}

/* Hero Section */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: 
        radial-gradient(circle at 20% 80%, rgba(120, 119, 198, 0.3) 0%, transparent 50%),
        radial-gradient(circle at 80% 20%, rgba(255, 255, 255, 0.1) 0%, transparent 50%),
        radial-gradient(circle at 40% 40%, rgba(120, 119, 198, 0.2) 0%, transparent 50%);
}

.hero::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100"><defs><pattern id="grain" width="100" height="100" patternUnits="userSpaceOnUse"><circle cx="50" cy="50" r="1" fill="%23ffffff" opacity="0.05"/></pattern></defs><rect width="100" height="100" fill="url(%23grain)"/></svg>');
    opacity: 0.3;
}

.hero-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    position: relative;
    z-index: 2;
}

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

.hero-text {
    animation: fadeInUp 1s ease-out;
    color: white;
}

.hero-text .greeting {
    color: rgba(255, 255, 255, 0.9);
}

.hero-text .hero-subtitle {
    color: rgba(255, 255, 255, 0.8);
}

.hero-text .hero-description {
    color: rgba(255, 255, 255, 0.7);
}

.greeting {
    display: block;
    font-size: 18px;
    color: #667eea;
    font-weight: 500;
    margin-bottom: 0.5rem;
}

.name {
    display: block;
    font-size: 3.5rem;
    font-weight: 700;
    color: white;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.3);
    margin-bottom: 1rem;
}

.hero-subtitle {
    font-size: 1.5rem;
    color: #555;
    margin-bottom: 1.5rem;
    font-weight: 400;
}

.hero-description {
    font-size: 18px;
    color: #666;
    margin-bottom: 2rem;
    line-height: 1.7;
}

.hero-stats {
    display: flex;
    gap: 2rem;
    margin-bottom: 2rem;
}

.stat {
    text-align: center;
}

.stat-number {
    display: block;
    font-size: 2rem;
    font-weight: 700;
    color: white;
    text-shadow: 1px 1px 2px rgba(0, 0, 0, 0.3);
}

.stat-label {
    font-size: 14px;
    color: rgba(255, 255, 255, 0.8);
    font-weight: 500;
}

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

.hero-image {
    display: flex;
    justify-content: center;
    animation: fadeInRight 1s ease-out 0.3s both;
}

.image-container {
    position: relative;
    width: 300px;
    height: 300px;
    border-radius: 50%;
    background: linear-gradient(135deg, rgba(255, 255, 255, 0.2) 0%, rgba(255, 255, 255, 0.1) 100%);
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 
        0 20px 40px rgba(0, 0, 0, 0.2),
        inset 0 1px 0 rgba(255, 255, 255, 0.3);
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.2);
    overflow: hidden;
}

.profile-image {
    width: 280px;
    height: 280px;
    object-fit: cover;
    object-position: center;
    border-radius: 50%;
    border: 3px solid rgba(255, 255, 255, 0.3);
}

.scroll-indicator {
    position: absolute;
    bottom: 2rem;
    left: 50%;
    transform: translateX(-50%);
    animation: bounce 2s infinite;
    cursor: pointer;
    transition: opacity 0.3s ease;
}

.scroll-indicator:hover {
    opacity: 0.7;
}

.scroll-arrow {
    width: 2px;
    height: 30px;
    background: white;
    position: relative;
}

.scroll-arrow::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 0;
    height: 0;
    border-left: 8px solid transparent;
    border-right: 8px solid transparent;
    border-top: 12px solid white;
}

/* Section Styles */
section {
    padding: 80px 0;
}

.section-header {
    text-align: center;
    margin-bottom: 4rem;
}

.section-title {
    font-size: 2.5rem;
    margin-bottom: 1rem;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.section-subtitle {
    font-size: 18px;
    color: #666;
    max-width: 600px;
    margin: 0 auto;
}

/* About Section */
.about {
    background: linear-gradient(135deg, #f8f9fa 0%, #e9ecef 100%);
    position: relative;
}

.about::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 60 60"><circle cx="30" cy="30" r="1" fill="%23667eea" opacity="0.05"/></svg>');
    pointer-events: none;
}

.about-text {
    max-width: 800px;
    margin: 0 auto;
    font-size: 16px;
    line-height: 1.8;
}

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

.about-highlights {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1.5rem;
    margin-top: 2rem;
}

.highlight {
    display: flex;
    align-items: center;
    gap: 1rem;
    padding: 1rem;
    background: white;
    border-radius: 8px;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}

.highlight i {
    font-size: 24px;
    color: #667eea;
}

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

.skill-item {
    background: white;
    padding: 2rem;
    border-radius: 12px;
    box-shadow: 0 5px 20px rgba(0, 0, 0, 0.1);
    text-align: center;
    transition: transform 0.3s ease;
}

.skill-item:hover {
    transform: translateY(-5px);
}

.skill-icon {
    width: 60px;
    height: 60px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 1rem;
}

.skill-icon i {
    font-size: 24px;
    color: white;
}

.skill-item h3 {
    margin-bottom: 1rem;
    color: #333;
}

.skill-bar {
    width: 100%;
    height: 8px;
    background: #e9ecef;
    border-radius: 4px;
    overflow: hidden;
    margin-bottom: 0.5rem;
}

.skill-progress {
    height: 100%;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    border-radius: 4px;
    width: 0;
    transition: width 2s ease-in-out;
}

.skill-percentage {
    font-weight: 600;
    color: #667eea;
}

/* Experience Section */
.experience {
    background: linear-gradient(135deg, #f8f9fa 0%, #e9ecef 100%);
    position: relative;
}

.experience::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 80 80"><rect x="39" y="39" width="2" height="2" fill="%23764ba2" opacity="0.03"/></svg>');
    pointer-events: none;
}

.timeline {
    position: relative;
    max-width: 800px;
    margin: 0 auto;
}

.timeline::before {
    content: '';
    position: absolute;
    left: 50%;
    top: 0;
    bottom: 0;
    width: 2px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    transform: translateX(-50%);
}

.timeline-item {
    position: relative;
    margin-bottom: 3rem;
    display: flex;
    align-items: center;
}

.timeline-item:nth-child(odd) {
    flex-direction: row;
}

.timeline-item:nth-child(even) {
    flex-direction: row-reverse;
}

.timeline-date {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 0.5rem 1rem;
    border-radius: 20px;
    font-weight: 600;
    font-size: 14px;
    white-space: nowrap;
    position: absolute;
    left: 50%;
    transform: translateX(-50%);
    z-index: 2;
}

.timeline-content {
    background: white;
    padding: 2rem;
    border-radius: 12px;
    box-shadow: 0 5px 20px rgba(0, 0, 0, 0.1);
    width: calc(50% - 2rem);
    position: relative;
}

.timeline-item:nth-child(odd) .timeline-content {
    margin-right: auto;
}

.timeline-item:nth-child(even) .timeline-content {
    margin-left: auto;
}

.timeline-content h3 {
    color: #333;
    margin-bottom: 0.5rem;
}

.timeline-content h4 {
    color: #667eea;
    font-weight: 500;
    margin-bottom: 1rem;
}

/* Education Section */
.education-category {
    margin-bottom: 3rem;
}

.education-category h3 {
    font-size: 1.5rem;
    margin-bottom: 2rem;
    color: #333;
    text-align: center;
}

.education-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-bottom: 3rem;
}

.education-item {
    background: white;
    padding: 2rem;
    border-radius: 12px;
    box-shadow: 0 5px 20px rgba(0, 0, 0, 0.1);
    display: flex;
    align-items: center;
    gap: 1rem;
}

.education-icon {
    width: 50px;
    height: 50px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}

.education-icon i {
    font-size: 20px;
    color: white;
}

.education-info h4 {
    color: #333;
    margin-bottom: 0.5rem;
}

.education-info p {
    color: #666;
    margin: 0;
}

/* Certifications */
.certifications {
    background: white;
    padding: 2rem;
    border-radius: 12px;
    box-shadow: 0 5px 20px rgba(0, 0, 0, 0.1);
}

.certifications h3 {
    text-align: center;
    margin-bottom: 2rem;
}

.cert-tabs {
    display: flex;
    justify-content: center;
    gap: 1rem;
    margin-bottom: 2rem;
    flex-wrap: wrap;
}

.cert-tab {
    padding: 0.5rem 1rem;
    border: 2px solid #e9ecef;
    background: transparent;
    border-radius: 20px;
    cursor: pointer;
    transition: all 0.3s ease;
    font-weight: 500;
}

.cert-tab.active,
.cert-tab:hover {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    border-color: transparent;
}

.cert-panel {
    display: none;
}

.cert-panel.active {
    display: block;
}

.cert-panel ul {
    list-style: none;
    padding: 0;
}

.cert-panel li {
    padding: 0.5rem 0;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.cert-panel li i {
    color: #28a745;
}

/* Research Section */
.research {
    background: linear-gradient(135deg, #f8f9fa 0%, #e9ecef 100%);
    position: relative;
}

.research::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 40 40"><circle cx="20" cy="20" r="0.5" fill="%23667eea" opacity="0.08"/></svg>');
    pointer-events: none;
}

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

.research-link {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 1rem 2rem;
    background: white;
    border-radius: 12px;
    text-decoration: none;
    color: #333;
    box-shadow: 0 5px 20px rgba(0, 0, 0, 0.1);
    transition: all 0.3s ease;
}

.research-link:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.15);
}

.research-link i {
    font-size: 24px;
    color: #667eea;
}

/* Contact Section */
.contact-content {
    display: grid;
    grid-template-columns: 1fr 2fr;
    gap: 4rem;
    max-width: 1000px;
    margin: 0 auto;
}

.contact-info h3 {
    margin-bottom: 2rem;
    color: #333;
}

.contact-item {
    display: flex;
    align-items: center;
    gap: 1rem;
    margin-bottom: 1.5rem;
}

.contact-item i {
    width: 40px;
    height: 40px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 16px;
}

.contact-link {
    color: inherit;
    text-decoration: none;
    transition: color 0.3s ease;
}

.contact-link:hover {
    color: #667eea;
    text-decoration: underline;
}

.social-links {
    display: flex;
    gap: 1rem;
    margin-top: 2rem;
}

.social-link {
    width: 40px;
    height: 40px;
    background: #f8f9fa;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: #667eea;
    text-decoration: none;
    transition: all 0.3s ease;
}

.social-link:hover {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    transform: translateY(-2px);
}

/* Contact Form */
.contact-form {
    background: white;
    padding: 2rem;
    border-radius: 12px;
    box-shadow: 0 5px 20px rgba(0, 0, 0, 0.1);
}

.form-group {
    margin-bottom: 1.5rem;
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 1rem;
    border: 2px solid #e9ecef;
    border-radius: 8px;
    font-size: 16px;
    transition: border-color 0.3s ease;
    font-family: inherit;
}

.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: #667eea;
}

.contact-form .btn {
    width: 100%;
    justify-content: center;
    position: relative;
}

.btn-loading {
    display: none;
}

.contact-form.loading .btn-text {
    display: none;
}

.contact-form.loading .btn-loading {
    display: inline;
}

/* Footer */
.footer {
    background: linear-gradient(135deg, #2c3e50 0%, #34495e 100%);
    color: white;
    padding: 3rem 0 2rem;
    position: relative;
    overflow: hidden;
}

.footer::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 1px;
    background: linear-gradient(90deg, transparent, rgba(255,255,255,0.2), transparent);
}

.footer-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 2rem;
}

.footer-text p {
    margin: 0;
    font-size: 14px;
    color: #bdc3c7;
}

.footer-social {
    display: flex;
    gap: 1rem;
}

.footer-social-link {
    width: 40px;
    height: 40px;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: #bdc3c7;
    text-decoration: none;
    transition: all 0.3s ease;
    backdrop-filter: blur(10px);
}

.footer-social-link:hover {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(102, 126, 234, 0.3);
}

/* Back to Top */
.back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 50px;
    height: 50px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    border: none;
    border-radius: 50%;
    cursor: pointer;
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s ease;
    z-index: 1000;
}

.back-to-top.visible {
    opacity: 1;
    visibility: visible;
}

.back-to-top:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(102, 126, 234, 0.3);
}

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

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

@keyframes bounce {
    0%, 20%, 50%, 80%, 100% {
        transform: translateY(0) translateX(-50%);
    }
    40% {
        transform: translateY(-10px) translateX(-50%);
    }
    60% {
        transform: translateY(-5px) translateX(-50%);
    }
}

/* Responsive Design */
@media (max-width: 768px) {
    .nav-menu {
        position: fixed;
        left: -100%;
        top: 70px;
        flex-direction: column;
        background-color: white;
        width: 100%;
        text-align: center;
        transition: 0.3s;
        box-shadow: 0 10px 27px rgba(0, 0, 0, 0.05);
        padding: 2rem 0;
    }

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

    .nav-toggle {
        display: flex;
    }

    .nav-toggle.active .bar:nth-child(2) {
        opacity: 0;
    }

    .nav-toggle.active .bar:nth-child(1) {
        transform: translateY(8px) rotate(45deg);
    }

    .nav-toggle.active .bar:nth-child(3) {
        transform: translateY(-8px) rotate(-45deg);
    }

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

    .name {
        font-size: 2.5rem;
    }

    .hero-stats {
        justify-content: center;
    }

    .timeline::before {
        left: 20px;
    }

    .timeline-item {
        flex-direction: column;
        align-items: flex-start;
        padding-left: 50px;
    }

    .timeline-date {
        position: static;
        transform: none;
        margin-bottom: 1rem;
        align-self: flex-start;
    }

    .timeline-content {
        width: 100%;
        margin: 0;
    }

    .contact-content {
        grid-template-columns: 1fr;
        gap: 2rem;
    }

    .hero-buttons {
        justify-content: center;
    }

    .cert-tabs {
        flex-direction: column;
        align-items: center;
    }

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

    .footer-content {
        flex-direction: column;
        text-align: center;
        gap: 1.5rem;
    }
    
    .footer-social {
        justify-content: center;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 15px;
    }

    .name {
        font-size: 2rem;
    }

    .hero-stats {
        flex-direction: column;
        gap: 1rem;
    }

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

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

    .about-highlights {
        grid-template-columns: 1fr;
    }
}

/* Print Styles */
@media print {
    .navbar,
    .back-to-top,
    .scroll-indicator {
        display: none;
    }

    body {
        font-size: 12pt;
        line-height: 1.4;
    }

    .hero {
        min-height: auto;
        padding: 2rem 0;
    }

    section {
        padding: 1rem 0;
        break-inside: avoid;
    }
}

/* Accessibility */
@media (prefers-reduced-motion: reduce) {
    * {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}

/* Focus styles for accessibility */
.btn:focus,
.nav-link:focus,
input:focus,
textarea:focus {
    outline: 2px solid #667eea;
    outline-offset: 2px;
}

/* High contrast mode support */
@media (prefers-contrast: high) {
    .btn-primary {
        background: #000;
        border: 2px solid #000;
    }

    .btn-secondary {
        background: #fff;
        color: #000;
        border: 2px solid #000;
    }
}