/* ============================================
   CSS Variables
   ============================================ */
:root {
    --color-primary: #3b82f6;
    --color-primary-dark: #2563eb;
    --color-secondary: #8b5cf6;
    --color-accent: #10b981;
    
    --color-bg: #ffffff;
    --color-bg-alt: #f8fafc;
    --color-bg-dark: #0f172a;
    --color-bg-dark-alt: #1e293b;
    
    --color-text: #1e293b;
    --color-text-light: #64748b;
    --color-text-lighter: #94a3b8;
    
    --color-border: #e2e8f0;
    --color-border-dark: #334155;
    
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
    
    --radius: 0.75rem;
    --radius-lg: 1rem;
    --radius-xl: 1.5rem;
    
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;
    --spacing-2xl: 4rem;
    
    --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    
    --transition: 200ms ease;
    --transition-slow: 300ms ease;
}

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

html {
    scroll-behavior: smooth;
    font-size: 16px;
}

body {
    font-family: var(--font-family);
    color: var(--color-text);
    background: var(--color-bg);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

.section {
    padding: var(--spacing-2xl) 0;
}

.section-title {
    font-size: clamp(2rem, 4vw, 3rem);
    font-weight: 800;
    text-align: center;
    margin-bottom: var(--spacing-xl);
    background: linear-gradient(135deg, var(--color-primary), var(--color-secondary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    letter-spacing: -0.02em;
}

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

.navbar.scrolled {
    box-shadow: var(--shadow-md);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: var(--spacing-sm) var(--spacing-md);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-logo .logo-text {
    font-size: 1.25rem;
    font-weight: 700;
    background: linear-gradient(135deg, var(--color-primary), var(--color-secondary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: var(--spacing-md);
    align-items: center;
}

.nav-link {
    text-decoration: none;
    color: var(--color-text);
    font-weight: 500;
    padding: var(--spacing-xs) var(--spacing-sm);
    border-radius: var(--radius);
    transition: all var(--transition);
    position: relative;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    width: 0;
    height: 2px;
    background: var(--color-primary);
    transform: translateX(-50%);
    transition: width var(--transition);
}

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

.nav-link:hover::after,
.nav-link.active::after {
    width: 80%;
}

.nav-link-special {
    background: linear-gradient(135deg, var(--color-primary), var(--color-secondary));
    color: white !important;
    padding: var(--spacing-xs) var(--spacing-md);
}

.nav-link-special::after {
    display: none;
}

.nav-link-special:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.nav-toggle {
    display: none;
    flex-direction: column;
    gap: 4px;
    background: none;
    border: none;
    cursor: pointer;
    padding: var(--spacing-xs);
}

.nav-toggle span {
    width: 24px;
    height: 2px;
    background: var(--color-text);
    transition: all var(--transition);
}

/* ============================================
   Hero Section
   ============================================ */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: var(--spacing-2xl) var(--spacing-md);
    padding-top: 100px;
    background: linear-gradient(135deg, #f8fafc 0%, #e0e7ff 100%);
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: -50%;
    right: -50%;
    width: 100%;
    height: 200%;
    background: radial-gradient(circle, rgba(59, 130, 246, 0.1) 0%, transparent 70%);
    animation: float 20s ease-in-out infinite;
}

@keyframes float {
    0%, 100% { transform: translate(0, 0) rotate(0deg); }
    50% { transform: translate(-20px, -20px) rotate(180deg); }
}

.hero-container {
    max-width: 1200px;
    width: 100%;
    z-index: 1;
}

.hero-content {
    display: grid;
    grid-template-columns: 300px 1fr;
    gap: var(--spacing-xl);
    align-items: center;
}

.hero-image-wrapper {
    position: relative;
}

.hero-image-placeholder {
    width: 300px;
    height: 300px;
    border-radius: 50%;
    overflow: hidden;
    box-shadow: var(--shadow-xl);
    position: relative;
    transition: transform var(--transition);
}

.hero-image-placeholder:hover {
    transform: scale(1.05);
}

.hero-profile-image {
    width: 100%;
    height: 100%;
    object-fit: cover;
    display: block;
}

.hero-text {
    max-width: 600px;
}

.hero-title {
    font-size: clamp(2.5rem, 5vw, 4rem);
    font-weight: 800;
    line-height: 1.1;
    margin-bottom: var(--spacing-md);
    color: var(--color-text);
}

.title-line {
    display: block;
}

.hero-subtitle {
    font-size: clamp(1.125rem, 2vw, 1.5rem);
    color: var(--color-primary);
    font-weight: 600;
    margin-bottom: var(--spacing-sm);
}

.hero-description {
    font-size: 1.125rem;
    color: var(--color-text-light);
    margin-bottom: var(--spacing-lg);
    line-height: 1.8;
}

.hero-buttons {
    display: flex;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-lg);
    flex-wrap: wrap;
}

.btn {
    padding: var(--spacing-sm) var(--spacing-lg);
    border-radius: var(--radius);
    font-weight: 600;
    text-decoration: none;
    transition: all var(--transition);
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-xs);
    border: none;
    cursor: pointer;
    font-size: 1rem;
    font-family: var(--font-family);
}

.btn-primary {
    background: linear-gradient(135deg, var(--color-primary), var(--color-secondary));
    color: white;
    box-shadow: var(--shadow-md);
}

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

.btn-secondary {
    background: white;
    color: var(--color-primary);
    border: 2px solid var(--color-primary);
}

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

.hero-social {
    display: flex;
    gap: var(--spacing-md);
}

.social-link {
    width: 44px;
    height: 44px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
    background: white;
    color: var(--color-text);
    transition: all var(--transition);
    box-shadow: var(--shadow-sm);
}

.social-link:hover {
    background: var(--color-primary);
    color: white;
    transform: translateY(-3px);
    box-shadow: var(--shadow-md);
}

.scroll-indicator {
    position: absolute;
    bottom: var(--spacing-lg);
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--spacing-xs);
    color: var(--color-text-light);
    font-size: 0.875rem;
    animation: bounce 2s infinite;
}

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

/* ============================================
   Experience Section
   ============================================ */
.experience-section {
    background: var(--color-bg-alt);
}

.timeline {
    position: relative;
    max-width: 900px;
    margin: 0 auto;
    padding-left: var(--spacing-lg);
}

.timeline::before {
    content: '';
    position: absolute;
    left: 0;
    top: 0;
    bottom: 0;
    width: 2px;
    background: linear-gradient(180deg, var(--color-primary), var(--color-secondary));
}

.timeline-item {
    position: relative;
    margin-bottom: var(--spacing-xl);
    padding-left: var(--spacing-xl);
}

.timeline-marker {
    position: absolute;
    left: -6px;
    top: 0;
    width: 14px;
    height: 14px;
    border-radius: 50%;
    background: var(--color-primary);
    border: 3px solid white;
    box-shadow: var(--shadow-md);
}

.timeline-content {
    background: white;
    padding: var(--spacing-lg);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    transition: all var(--transition);
}

.timeline-content:hover {
    transform: translateX(10px);
    box-shadow: var(--shadow-lg);
}

.timeline-header {
    margin-bottom: var(--spacing-md);
}

.timeline-title {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--color-text);
    margin-bottom: var(--spacing-xs);
}

.timeline-company {
    display: block;
    color: var(--color-primary);
    font-weight: 600;
    margin-bottom: var(--spacing-xs);
}

.timeline-date {
    display: block;
    color: var(--color-text-light);
    font-size: 0.875rem;
}

.timeline-description {
    list-style: none;
    color: var(--color-text-light);
}

.timeline-description li {
    margin-bottom: var(--spacing-sm);
    padding-left: var(--spacing-md);
    position: relative;
}

.timeline-description li::before {
    content: '▸';
    position: absolute;
    left: 0;
    color: var(--color-primary);
    font-weight: bold;
}

.timeline-description li strong {
    color: var(--color-text);
}

/* ============================================
   Projects Section
   ============================================ */
.projects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--spacing-lg);
    margin-top: var(--spacing-xl);
}

.project-card-link {
    text-decoration: none;
    color: inherit;
    display: block;
}

.project-card {
    background: white;
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    box-shadow: var(--shadow-md);
    transition: all var(--transition);
    border: 1px solid var(--color-border);
    display: flex;
    flex-direction: column;
    cursor: pointer;
}

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

.project-card.featured {
    border: 2px solid var(--color-primary);
    background: linear-gradient(135deg, rgba(59, 130, 246, 0.05), rgba(139, 92, 246, 0.05));
}

.project-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-md);
}

.project-icon {
    width: 48px;
    height: 48px;
    border-radius: var(--radius);
    background: linear-gradient(135deg, var(--color-primary), var(--color-secondary));
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
}

.project-badge {
    background: var(--color-accent);
    color: white;
    padding: 0.25rem 0.75rem;
    border-radius: 999px;
    font-size: 0.75rem;
    font-weight: 600;
}

.project-title {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: var(--spacing-sm);
    color: var(--color-text);
}

.project-description {
    color: var(--color-text-light);
    margin-bottom: var(--spacing-md);
    flex: 1;
    line-height: 1.7;
}

.project-tech {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-xs);
    margin-bottom: var(--spacing-md);
}

.tech-tag {
    background: var(--color-bg-alt);
    color: var(--color-text);
    padding: 0.25rem 0.75rem;
    border-radius: 999px;
    font-size: 0.875rem;
    font-weight: 500;
    border: 1px solid var(--color-border);
}

.project-links {
    margin-top: auto;
}

.project-link {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-xs);
    color: var(--color-primary);
    text-decoration: none;
    font-weight: 600;
    transition: all var(--transition);
}

.project-link:hover {
    gap: var(--spacing-sm);
    color: var(--color-primary-dark);
}

.project-highlight {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    color: var(--color-accent);
    font-size: 0.875rem;
    font-weight: 600;
    margin-top: var(--spacing-sm);
}

/* Project Video Section - Large Display */
.project-video-section {
    max-width: 1000px;
    margin: 0 auto var(--spacing-2xl);
    padding: var(--spacing-xl);
    background: white;
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-lg);
    border: 1px solid var(--color-border);
}

.video-section-title {
    font-size: 1.75rem;
    font-weight: 700;
    color: var(--color-text);
    margin-bottom: var(--spacing-sm);
    text-align: center;
}

.video-section-description {
    font-size: 1rem;
    color: var(--color-text-light);
    text-align: center;
    margin-bottom: var(--spacing-xl);
}

.video-fallback-text {
    text-align: center;
    margin-top: var(--spacing-md);
    font-size: 0.875rem;
    color: var(--color-text-light);
}

.video-fallback-text a {
    color: var(--color-primary);
    text-decoration: none;
    font-weight: 500;
}

.video-fallback-text a:hover {
    text-decoration: underline;
}

.video-wrapper-large {
    position: relative;
    width: 100%;
    padding-bottom: 56.25%; /* 16:9 aspect ratio */
    height: 0;
    overflow: hidden;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-xl);
    background: #000;
}

.project-video-large {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    border: none;
}

/* ============================================
   Education Section
   ============================================ */
.education-section {
    background: var(--color-bg-alt);
}

.education-card {
    max-width: 800px;
    margin: 0 auto;
    background: white;
    border-radius: var(--radius-lg);
    padding: var(--spacing-xl);
    box-shadow: var(--shadow-md);
}

.education-header {
    display: flex;
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-lg);
    align-items: flex-start;
}

.education-icon {
    width: 64px;
    height: 64px;
    border-radius: var(--radius);
    background: linear-gradient(135deg, var(--color-primary), var(--color-secondary));
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    flex-shrink: 0;
}

.education-info {
    flex: 1;
}

.education-degree {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: var(--spacing-xs);
    color: var(--color-text);
}

.education-school {
    font-size: 1.125rem;
    color: var(--color-primary);
    font-weight: 600;
    margin-bottom: var(--spacing-xs);
}

.education-location {
    color: var(--color-text-light);
}

.education-details {
    display: flex;
    justify-content: space-between;
    padding-top: var(--spacing-lg);
    border-top: 1px solid var(--color-border);
    color: var(--color-text-light);
    font-weight: 500;
}

/* ============================================
   Certifications Hero Section
   ============================================ */
.certifications-hero-section {
    background: var(--color-bg-alt);
}

.certifications-gallery {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--spacing-lg);
    max-width: 1200px;
    margin: 0 auto;
}

.cert-display-area {
    position: relative;
    aspect-ratio: 4 / 3;
    border-radius: var(--radius-lg);
    overflow: hidden;
    background: white;
    border: 1px solid var(--color-border);
    transition: all var(--transition);
    display: flex;
    flex-direction: column;
    box-shadow: var(--shadow-md);
    cursor: pointer;
}

.cert-display-area:hover {
    border-color: var(--color-primary);
    box-shadow: var(--shadow-xl);
    transform: translateY(-5px);
}

.cert-image {
    width: 100%;
    height: 100%;
    object-fit: contain;
    background: white;
    padding: var(--spacing-md);
    flex: 1;
    transition: transform var(--transition);
}

.cert-display-area:hover .cert-image {
    transform: scale(1.05);
}

.cert-label {
    background: linear-gradient(135deg, var(--color-primary), var(--color-secondary));
    color: white;
    padding: var(--spacing-sm) var(--spacing-md);
    text-align: center;
    font-weight: 600;
    font-size: 0.875rem;
    margin-top: auto;
}

/* Certification Modal/Lightbox */
.cert-modal {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    z-index: 9999;
    display: none;
    align-items: center;
    justify-content: center;
    padding: var(--spacing-lg);
    animation: fadeIn var(--transition-slow);
}

.cert-modal.active {
    display: flex;
}

.cert-modal-overlay {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.9);
    backdrop-filter: blur(5px);
}

.cert-modal-content {
    position: relative;
    z-index: 1;
    max-width: 90vw;
    max-height: 90vh;
    background: white;
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-xl);
    overflow: hidden;
    display: flex;
    flex-direction: column;
    animation: scaleIn var(--transition-slow);
}

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

@keyframes scaleIn {
    from {
        transform: scale(0.9);
        opacity: 0;
    }
    to {
        transform: scale(1);
        opacity: 1;
    }
}

.cert-modal-close {
    position: absolute;
    top: var(--spacing-md);
    right: var(--spacing-md);
    z-index: 10;
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background: rgba(0, 0, 0, 0.7);
    border: none;
    color: white;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all var(--transition);
    backdrop-filter: blur(10px);
}

.cert-modal-close:hover {
    background: rgba(0, 0, 0, 0.9);
    transform: rotate(90deg);
}

.cert-modal-image-wrapper {
    max-width: 100%;
    max-height: 80vh;
    overflow: auto;
    display: flex;
    align-items: center;
    justify-content: center;
    background: #f8f9fa;
    padding: var(--spacing-xl);
}

.cert-modal-image {
    max-width: 100%;
    max-height: 80vh;
    object-fit: contain;
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-lg);
}

.cert-modal-title {
    padding: var(--spacing-md) var(--spacing-lg);
    background: linear-gradient(135deg, var(--color-primary), var(--color-secondary));
    color: white;
    text-align: center;
    font-weight: 600;
    font-size: 1.125rem;
}

/* ============================================
   Skills Section
   ============================================ */
.skills-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-xl);
}

.skills-category {
    background: white;
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    box-shadow: var(--shadow-md);
}

.category-title {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    font-size: 1.25rem;
    font-weight: 700;
    margin-bottom: var(--spacing-md);
    color: var(--color-text);
}

.category-title svg {
    color: var(--color-primary);
}

.skills-list {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-sm);
}

.skill-item {
    background: var(--color-bg-alt);
    padding: var(--spacing-xs) var(--spacing-md);
    border-radius: var(--radius);
    font-weight: 500;
    color: var(--color-text);
    border: 1px solid var(--color-border);
    transition: all var(--transition);
}

.skill-item:hover {
    background: var(--color-primary);
    color: white;
    transform: translateY(-2px);
    box-shadow: var(--shadow-sm);
}

.certifications,
.activities {
    background: white;
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    box-shadow: var(--shadow-md);
    margin-top: var(--spacing-lg);
}

.certifications-title,
.activities-title {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: var(--spacing-md);
    color: var(--color-text);
}

.cert-grid {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.cert-item {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    color: var(--color-text-light);
    font-weight: 500;
}

.cert-item svg {
    color: var(--color-accent);
    flex-shrink: 0;
}

.activity-item {
    display: flex;
    gap: var(--spacing-md);
    align-items: flex-start;
}

.activity-item svg {
    color: var(--color-primary);
    flex-shrink: 0;
    margin-top: 4px;
}

.activity-item strong {
    display: block;
    color: var(--color-text);
    margin-bottom: var(--spacing-xs);
}

.activity-item p {
    color: var(--color-text-light);
    margin: 0;
}

/* ============================================
   Footer
   ============================================ */
.footer {
    background: var(--color-text);
    color: white;
    padding: var(--spacing-xl) 0;
    text-align: center;
}

.footer-text {
    margin-bottom: var(--spacing-md);
    color: rgba(255, 255, 255, 0.8);
}

.footer-links {
    display: flex;
    justify-content: center;
    gap: var(--spacing-lg);
    flex-wrap: wrap;
}

.footer-links a {
    color: white;
    text-decoration: none;
    transition: all var(--transition);
}

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

/* ============================================
   Responsive Design
   ============================================ */
@media (max-width: 768px) {
    .nav-menu {
        position: fixed;
        top: 70px;
        left: -100%;
        flex-direction: column;
        background: white;
        width: 100%;
        padding: var(--spacing-lg);
        box-shadow: var(--shadow-lg);
        transition: left var(--transition);
        align-items: flex-start;
    }

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

    .nav-toggle {
        display: flex;
    }

    .certifications-gallery {
        grid-template-columns: 1fr;
    }

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

    .hero-image-wrapper {
        margin: 0 auto;
    }

    .hero-image-placeholder {
        width: 250px;
        height: 250px;
    }

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

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

    .timeline {
        padding-left: var(--spacing-md);
    }

    .timeline-item {
        padding-left: var(--spacing-lg);
    }

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

    .education-header {
        flex-direction: column;
        text-align: center;
    }

    .education-details {
        flex-direction: column;
        gap: var(--spacing-xs);
        text-align: center;
    }

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

@media (max-width: 480px) {
    .section {
        padding: var(--spacing-xl) 0;
    }

    .hero {
        padding-top: 80px;
    }

    .hero-image-placeholder {
        width: 200px;
        height: 200px;
    }

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

    .btn {
        width: 100%;
        justify-content: center;
    }
}