/* ============================================
   GLOBAL STYLES - Main Portfolio
   ============================================ */

/* CSS Variables */
:root {
    /* Colors - Dark Theme (Default) */
    --primary: #007AFF;
    --secondary: #FE6D33;
    --success: #00C853;
    --warning: #FFB300;
    --danger: #FF3B30;
    
    --bg-primary: #0E0E0E;
    --bg-secondary: #1C1C1E;
    --bg-card: #2C2C2E;
    --bg-hover: #3C3C3E;
    
    --text-primary: #FFFFFF;
    --text-secondary: #8E8E93;
    --text-muted: #636366;
    
    --border-color: rgba(255, 255, 255, 0.1);
    
    /* Gradients */
    --gradient-primary: linear-gradient(135deg, #007AFF, #00f2fe);
    --gradient-secondary: linear-gradient(135deg, #FE6D33, #FF9A5A);
    --gradient-success: linear-gradient(135deg, #00C853, #64DD17);
    --gradient-text: linear-gradient(135deg, #007AFF 0%, #00f2fe 50%, #FE6D33 100%);
    
    /* Typography */
    --font-primary: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --font-mono: 'JetBrains Mono', 'Fira Code', monospace;
    
    /* Spacing */
    --space-xs: 0.25rem;
    --space-sm: 0.5rem;
    --space-md: 1rem;
    --space-lg: 1.5rem;
    --space-xl: 2rem;
    --space-2xl: 3rem;
    --space-3xl: 4rem;
    
    /* Transitions */
    --transition-fast: 0.2s ease;
    --transition-base: 0.3s ease;
    --transition-slow: 0.5s ease;
    
    /* Shadows */
    --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.1);
    --shadow-md: 0 4px 8px rgba(0, 0, 0, 0.15);
    --shadow-lg: 0 10px 30px rgba(0, 0, 0, 0.2);
    --shadow-xl: 0 20px 60px rgba(0, 0, 0, 0.3);
    
    /* Z-index */
    --z-dropdown: 100;
    --z-sticky: 200;
    --z-fixed: 300;
    --z-modal-backdrop: 400;
    --z-modal: 500;
    --z-popover: 600;
    --z-tooltip: 700;
}

/* Light Theme */
[data-theme="light"] {
    --bg-primary: #FFFFFF;
    --bg-secondary: #F5F5F7;
    --bg-card: #FFFFFF;
    --bg-hover: #E5E5E7;
    
    --text-primary: #1D1D1F;
    --text-secondary: #86868B;
    --text-muted: #A1A1A6;
    
    --border-color: rgba(0, 0, 0, 0.1);
    
    --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 8px rgba(0, 0, 0, 0.08);
    --shadow-lg: 0 10px 30px rgba(0, 0, 0, 0.1);
    --shadow-xl: 0 20px 60px rgba(0, 0, 0, 0.15);
}

/* ============================================
   RESET & BASE STYLES
   ============================================ */

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

html {
    scroll-behavior: smooth;
    scroll-padding-top: 80px;
}

body {
    font-family: var(--font-primary);
    background: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    overflow-x: hidden;
    transition: background-color var(--transition-base);
}

/* Selection */
::selection {
    background: var(--primary);
    color: white;
}

/* Scrollbar */
::-webkit-scrollbar {
    width: 10px;
    height: 10px;
}

::-webkit-scrollbar-track {
    background: var(--bg-secondary);
}

::-webkit-scrollbar-thumb {
    background: var(--primary);
    border-radius: 5px;
}

::-webkit-scrollbar-thumb:hover {
    background: #0066DD;
}

/* Links */
a {
    text-decoration: none;
    color: inherit;
    transition: color var(--transition-base);
}

/* Images */
img {
    max-width: 100%;
    height: auto;
    display: block;
}

/* Lists */
ul, ol {
    list-style: none;
}

/* Buttons */
button {
    border: none;
    background: none;
    cursor: pointer;
    font-family: inherit;
}

/* ============================================
   UTILITIES
   ============================================ */

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

.gradient-text {
    background: var(--gradient-text);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    background-size: 200% auto;
    animation: shimmer 3s linear infinite;
}

@keyframes shimmer {
    to { background-position: 200% center; }
}

/* ============================================
   LOADING SCREEN
   ============================================ */

.loader {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: var(--bg-primary);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1000;
    transition: opacity var(--transition-slow);
}

.loader.hidden {
    opacity: 0;
    pointer-events: none;
}

.loader-content {
    text-align: center;
}

.loader-logo {
    font-size: 3rem;
    color: var(--primary);
    animation: pulse 1.5s ease-in-out infinite;
}

@keyframes pulse {
    0%, 100% { transform: scale(1); opacity: 1; }
    50% { transform: scale(1.1); opacity: 0.8; }
}

.loader-bar {
    width: 150px;
    height: 4px;
    background: var(--bg-secondary);
    border-radius: 2px;
    margin-top: var(--space-xl);
    overflow: hidden;
}

.loader-bar::after {
    content: '';
    display: block;
    width: 50%;
    height: 100%;
    background: var(--gradient-primary);
    animation: loading 1.5s ease-in-out infinite;
}

@keyframes loading {
    0% { transform: translateX(-100%); }
    100% { transform: translateX(300%); }
}

/* ============================================
   NAVIGATION
   ============================================ */

.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: var(--z-sticky);
    background: rgba(28, 28, 30, 0.95);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--border-color);
    transition: all var(--transition-base);
}

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

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 1rem var(--space-xl);
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.nav-logo {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    font-size: 1.5rem;
    font-weight: 800;
    color: var(--text-primary);
}

.logo-icon {
    font-size: 1.8rem;
}

.nav-menu {
    display: flex;
    gap: var(--space-2xl);
    align-items: center;
}

.nav-link {
    color: var(--text-secondary);
    font-weight: 500;
    position: relative;
    transition: color var(--transition-base);
}

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

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

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

.theme-toggle {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background: var(--bg-card);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.2rem;
    transition: all var(--transition-base);
    margin-left: var(--space-xl);
}

.theme-toggle:hover {
    background: var(--bg-hover);
    transform: rotate(20deg);
}

.nav-toggle {
    display: none;
    flex-direction: column;
    gap: 4px;
    width: 30px;
    height: 30px;
    justify-content: center;
}

.nav-toggle span {
    width: 100%;
    height: 2px;
    background: var(--text-primary);
    transition: all var(--transition-base);
}

.nav-toggle.active span:nth-child(1) {
    transform: rotate(45deg) translate(5px, 5px);
}

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

.nav-toggle.active span:nth-child(3) {
    transform: rotate(-45deg) translate(7px, -6px);
}

/* ============================================
   HERO SECTION
   ============================================ */

.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    padding: 6rem 0 4rem;
    position: relative;
}

.hero-bg {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    overflow: hidden;
    z-index: -1;
}

.gradient-orb {
    position: absolute;
    border-radius: 50%;
    filter: blur(100px);
    opacity: 0.3;
    animation: float 20s ease-in-out infinite;
}

.orb-1 {
    width: 600px;
    height: 600px;
    background: radial-gradient(circle, var(--primary), transparent);
    top: -200px;
    right: -200px;
    animation-duration: 25s;
}

.orb-2 {
    width: 500px;
    height: 500px;
    background: radial-gradient(circle, var(--secondary), transparent);
    bottom: -200px;
    left: -200px;
    animation-duration: 30s;
    animation-delay: 5s;
}

.orb-3 {
    width: 400px;
    height: 400px;
    background: radial-gradient(circle, var(--success), transparent);
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    animation-duration: 35s;
    animation-delay: 10s;
}

@keyframes float {
    0%, 100% { transform: translate(0, 0) scale(1); }
    25% { transform: translate(100px, -100px) scale(1.1); }
    50% { transform: translate(-100px, 100px) scale(0.9); }
    75% { transform: translate(50px, 50px) scale(1.05); }
}

#particleCanvas {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    opacity: 0.5;
}

.hero-content {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--space-xl);
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--space-3xl);
    align-items: center;
    position: relative;
    z-index: 1;
}

.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: var(--space-sm);
    padding: var(--space-sm) var(--space-md);
    background: rgba(0, 122, 255, 0.1);
    border: 1px solid rgba(0, 122, 255, 0.3);
    border-radius: 50px;
    font-size: 0.9rem;
    margin-bottom: var(--space-xl);
    animation: fadeInUp 0.8s ease;
}

.hero-title {
    font-size: clamp(2.5rem, 5vw, 4rem);
    font-weight: 900;
    line-height: 1.1;
    margin-bottom: var(--space-md);
    animation: fadeInUp 0.8s ease 0.1s both;
}

.hero-subtitle {
    font-size: clamp(1.5rem, 3vw, 2rem);
    font-weight: 600;
    color: var(--text-secondary);
    margin-bottom: var(--space-lg);
    animation: fadeInUp 0.8s ease 0.2s both;
}

.hero-description {
    font-size: 1.125rem;
    color: var(--text-secondary);
    line-height: 1.8;
    margin-bottom: var(--space-2xl);
    animation: fadeInUp 0.8s ease 0.3s both;
}

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

.hero-buttons {
    display: flex;
    gap: var(--space-md);
    flex-wrap: wrap;
    margin-bottom: var(--space-2xl);
    animation: fadeInUp 0.8s ease 0.4s both;
}

.btn {
    padding: var(--space-md) var(--space-xl);
    border-radius: 12px;
    font-weight: 600;
    display: inline-flex;
    align-items: center;
    gap: var(--space-sm);
    transition: all var(--transition-base);
    position: relative;
    overflow: hidden;
}

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

.btn-primary::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: rgba(255, 255, 255, 0.2);
    transition: left var(--transition-slow);
}

.btn-primary:hover::before {
    left: 100%;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 30px rgba(0, 122, 255, 0.3);
}

.btn-secondary {
    background: var(--bg-card);
    color: var(--text-primary);
    border: 1px solid var(--border-color);
}

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

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

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

.btn-large {
    padding: 1.25rem 2rem;
    font-size: 1.125rem;
}

.hero-stats {
    display: flex;
    gap: var(--space-2xl);
    animation: fadeInUp 0.8s ease 0.5s both;
}

.stat {
    text-align: center;
}

.stat-value {
    display: block;
    font-size: 2rem;
    font-weight: 800;
    color: var(--primary);
}

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

/* Code Window */
.code-window {
    background: var(--bg-secondary);
    border-radius: 16px;
    overflow: hidden;
    box-shadow: var(--shadow-xl);
    animation: fadeInUp 0.8s ease 0.6s both;
}

.window-header {
    background: var(--bg-card);
    padding: var(--space-md);
    display: flex;
    align-items: center;
    justify-content: space-between;
    border-bottom: 1px solid var(--border-color);
}

.window-dots {
    display: flex;
    gap: 8px;
}

.window-dots span {
    width: 12px;
    height: 12px;
    border-radius: 50%;
    display: block;
}

.window-dots span:nth-child(1) { background: #FF5F56; }
.window-dots span:nth-child(2) { background: #FFBD2E; }
.window-dots span:nth-child(3) { background: #27C93F; }

.window-title {
    font-size: 0.9rem;
    color: var(--text-secondary);
    font-family: var(--font-mono);
}

.code-content {
    padding: var(--space-xl);
    font-family: var(--font-mono);
    font-size: 0.9rem;
    line-height: 1.8;
    overflow-x: auto;
}

.code-content code {
    color: var(--text-primary);
}

.keyword { color: #FF79C6; }
.class { color: #8BE9FD; }
.function { color: #50FA7B; }
.comment { color: #6272A4; font-style: italic; }

/* ============================================
   PROJECTS SECTION
   ============================================ */

.projects {
    padding: 6rem 0;
    background: var(--bg-secondary);
}

.section-header {
    text-align: center;
    margin-bottom: var(--space-3xl);
}

.section-badge {
    display: inline-block;
    padding: var(--space-xs) var(--space-md);
    background: rgba(0, 122, 255, 0.1);
    color: var(--primary);
    border-radius: 50px;
    font-size: 0.875rem;
    font-weight: 600;
    margin-bottom: var(--space-md);
}

.section-title {
    font-size: clamp(2rem, 4vw, 3rem);
    font-weight: 800;
    margin-bottom: var(--space-md);
}

.section-description {
    font-size: 1.125rem;
    color: var(--text-secondary);
}

.project-filters {
    display: flex;
    justify-content: center;
    gap: var(--space-md);
    margin-bottom: var(--space-3xl);
    flex-wrap: wrap;
}

.filter-btn {
    padding: var(--space-sm) var(--space-lg);
    background: var(--bg-card);
    border-radius: 50px;
    color: var(--text-secondary);
    font-weight: 500;
    transition: all var(--transition-base);
}

.filter-btn:hover {
    background: var(--bg-hover);
    color: var(--text-primary);
}

.filter-btn.active {
    background: var(--gradient-primary);
    color: white;
}

.projects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(350px, 1fr));
    gap: var(--space-2xl);
}

.project-card {
    background: var(--bg-card);
    border-radius: 20px;
    overflow: hidden;
    transition: all var(--transition-base);
    border: 1px solid var(--border-color);
}

.project-card:hover {
    transform: translateY(-10px);
    box-shadow: var(--shadow-xl);
    border-color: var(--primary);
}

.project-image {
    position: relative;
    height: 250px;
    overflow: hidden;
    background: var(--bg-hover);
}

.project-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform var(--transition-slow);
}

.project-card:hover .project-image img {
    transform: scale(1.1);
}

.project-overlay {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.8);
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    transition: opacity var(--transition-base);
}

.project-card:hover .project-overlay {
    opacity: 1;
}

.project-link {
    color: white;
    font-weight: 600;
    padding: var(--space-sm) var(--space-lg);
    background: var(--gradient-primary);
    border-radius: 50px;
    transform: translateY(20px);
    transition: transform var(--transition-base);
}

.project-card:hover .project-link {
    transform: translateY(0);
}

.project-content {
    padding: var(--space-xl);
}

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

.project-header h3 {
    font-size: 1.5rem;
    font-weight: 700;
}

.project-badge {
    padding: var(--space-xs) var(--space-sm);
    background: rgba(0, 122, 255, 0.1);
    color: var(--primary);
    border-radius: 6px;
    font-size: 0.75rem;
    font-weight: 600;
}

.badge-new {
    background: rgba(0, 200, 83, 0.1);
    color: var(--success);
}

.project-content p {
    color: var(--text-secondary);
    margin-bottom: var(--space-lg);
    line-height: 1.6;
}

.project-tech {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-sm);
    margin-bottom: var(--space-lg);
}

.tech-tag {
    padding: var(--space-xs) var(--space-sm);
    background: var(--bg-hover);
    border-radius: 6px;
    font-size: 0.875rem;
    color: var(--text-secondary);
}

.project-links {
    display: flex;
    gap: var(--space-md);
}

.project-links a {
    font-size: 0.9rem;
    font-weight: 500;
    color: var(--primary);
}

.project-links a:hover {
    text-decoration: underline;
}

.more-projects {
    grid-column: 1 / -1;
    text-align: center;
    margin-top: var(--space-2xl);
}

/* ============================================
   SKILLS SECTION
   ============================================ */

.skills {
    padding: 6rem 0;
}

.skills-container {
    display: grid;
    gap: var(--space-3xl);
}

.skill-category {
    background: var(--bg-secondary);
    border-radius: 20px;
    padding: var(--space-2xl);
    border: 1px solid var(--border-color);
}

.category-title {
    display: flex;
    align-items: center;
    gap: var(--space-md);
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: var(--space-xl);
}

.category-icon {
    font-size: 1.8rem;
}

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

.skill-item {
    background: var(--bg-card);
    padding: var(--space-lg);
    border-radius: 12px;
}

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

.skill-name {
    font-weight: 600;
}

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

.skill-bar {
    height: 8px;
    background: var(--bg-hover);
    border-radius: 4px;
    overflow: hidden;
}

.skill-progress {
    height: 100%;
    background: var(--gradient-primary);
    border-radius: 4px;
    animation: fillBar 1.5s ease-out;
}

@keyframes fillBar {
    from { width: 0; }
}

.skills-tags {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-md);
}

.skill-tag {
    padding: var(--space-sm) var(--space-lg);
    background: var(--bg-card);
    border-radius: 50px;
    font-weight: 500;
    transition: all var(--transition-base);
}

.skill-tag:hover {
    background: var(--gradient-primary);
    color: white;
    transform: translateY(-2px);
}

/* ============================================
   ABOUT SECTION
   ============================================ */

.about {
    padding: 6rem 0;
    background: var(--bg-secondary);
}

.about-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--space-3xl);
    align-items: center;
}

.about-text p {
    color: var(--text-secondary);
    line-height: 1.8;
    margin-bottom: var(--space-xl);
}

.about-highlights {
    display: grid;
    gap: var(--space-xl);
    margin-top: var(--space-2xl);
}

.highlight {
    display: flex;
    gap: var(--space-lg);
    align-items: center;
}

.highlight-icon {
    font-size: 2rem;
    width: 60px;
    height: 60px;
    background: var(--bg-card);
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.highlight h4 {
    font-size: 1.125rem;
    margin-bottom: var(--space-xs);
}

.highlight p {
    color: var(--text-secondary);
    margin: 0;
}

.image-container {
    position: relative;
}

.image-container img {
    width: 100%;
    max-width: 400px;
    margin: 0 auto;
    border-radius: 20px;
    position: relative;
    z-index: 2;
}

.image-decoration {
    position: absolute;
    top: 20px;
    left: 20px;
    right: -20px;
    bottom: -20px;
    background: var(--gradient-primary);
    border-radius: 20px;
    z-index: 1;
}

.about-socials {
    display: flex;
    gap: var(--space-md);
    margin-top: var(--space-2xl);
    justify-content: center;
}

.social-link {
    width: 50px;
    height: 50px;
    background: var(--bg-card);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all var(--transition-base);
}

.social-link:hover {
    background: var(--gradient-primary);
    transform: translateY(-5px);
}

.social-link svg {
    width: 24px;
    height: 24px;
    fill: var(--text-primary);
}

.social-link:hover svg {
    fill: white;
}

/* ============================================
   CONTACT SECTION
   ============================================ */

.contact {
    padding: 6rem 0;
}

.contact-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--space-3xl);
    margin-top: var(--space-3xl);
}

.contact-info {
    display: grid;
    gap: var(--space-2xl);
}

.contact-item {
    display: flex;
    gap: var(--space-lg);
    align-items: center;
}

.contact-icon {
    font-size: 2rem;
    width: 60px;
    height: 60px;
    background: var(--bg-secondary);
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.contact-item h4 {
    font-size: 1.125rem;
    margin-bottom: var(--space-xs);
}

.contact-item a {
    color: var(--primary);
}

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

.contact-form {
    display: grid;
    gap: var(--space-lg);
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: var(--space-md) var(--space-lg);
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    color: var(--text-primary);
    font-family: inherit;
    font-size: 1rem;
    transition: all var(--transition-base);
}

.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--primary);
    background: var(--bg-card);
}

.form-group textarea {
    resize: vertical;
}

/* ============================================
   FOOTER
   ============================================ */

.footer {
    padding: 4rem 0 2rem;
    background: var(--bg-secondary);
    border-top: 1px solid var(--border-color);
}

.footer-content {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr;
    gap: var(--space-3xl);
    margin-bottom: var(--space-2xl);
}

.footer-brand h3 {
    font-size: 1.5rem;
    margin-bottom: var(--space-md);
}

.footer-brand p {
    color: var(--text-secondary);
}

.footer-links h4,
.footer-social h4 {
    font-size: 1.125rem;
    margin-bottom: var(--space-lg);
}

.footer-links a,
.social-links a {
    display: block;
    color: var(--text-secondary);
    margin-bottom: var(--space-sm);
}

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

.footer-bottom {
    text-align: center;
    padding-top: var(--space-2xl);
    border-top: 1px solid var(--border-color);
    color: var(--text-secondary);
}

/* ============================================
   CERTIFICATIONS SECTION
   ============================================ */

.certifications {
    padding: 6rem 0;
    background: var(--bg-secondary);
}

.certifications-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: var(--space-xl);
}

.cert-card {
    background: var(--bg-card);
    border-radius: 16px;
    padding: var(--space-xl);
    border: 1px solid var(--border-color);
    transition: all var(--transition-base);
    position: relative;
    overflow: hidden;
}

.cert-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: var(--gradient-primary);
    transform: scaleX(0);
    transition: transform var(--transition-base);
}

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

.cert-card:hover::before {
    transform: scaleX(1);
}

.cert-icon {
    font-size: 2.5rem;
    margin-bottom: var(--space-md);
}

.cert-card h4 {
    font-size: 1.125rem;
    font-weight: 700;
    margin-bottom: var(--space-sm);
    color: var(--text-primary);
}

.cert-card p {
    font-size: 0.9rem;
    color: var(--text-secondary);
    margin-bottom: var(--space-md);
}

.cert-year {
    display: inline-block;
    padding: var(--space-xs) var(--space-sm);
    background: rgba(0, 122, 255, 0.1);
    color: var(--primary);
    border-radius: 6px;
    font-size: 0.8rem;
    font-weight: 600;
}

/* ============================================
   OPEN SOURCE SECTION
   ============================================ */

.opensource {
    padding: 6rem 0;
}

.opensource-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(350px, 1fr));
    gap: var(--space-xl);
}

.opensource-card {
    background: var(--bg-secondary);
    border-radius: 16px;
    padding: var(--space-xl);
    border: 1px solid var(--border-color);
    transition: all var(--transition-base);
}

.opensource-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
    border-color: var(--primary);
}

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

.os-icon {
    font-size: 2rem;
}

.os-link {
    font-size: 0.9rem;
    color: var(--primary);
    font-weight: 500;
}

.os-link:hover {
    text-decoration: underline;
}

.opensource-card h4 {
    font-size: 1.25rem;
    font-weight: 700;
    margin-bottom: var(--space-md);
}

.opensource-card p {
    color: var(--text-secondary);
    line-height: 1.6;
    margin-bottom: var(--space-lg);
}

.os-tags {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-sm);
}

.os-tags span {
    padding: var(--space-xs) var(--space-sm);
    background: var(--bg-card);
    border-radius: 6px;
    font-size: 0.8rem;
    color: var(--text-secondary);
}

/* ============================================
   BACK TO TOP
   ============================================ */

.back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 50px;
    height: 50px;
    background: var(--gradient-primary);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition-base);
    z-index: var(--z-fixed);
}

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

.back-to-top:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 30px rgba(0, 122, 255, 0.3);
}

/* ============================================
   RESPONSIVE
   ============================================ */

@media (max-width: 768px) {
    .nav-menu {
        position: fixed;
        left: -100%;
        top: 70px;
        flex-direction: column;
        background: var(--bg-secondary);
        width: 100%;
        text-align: center;
        transition: var(--transition-base);
        box-shadow: var(--shadow-lg);
        padding: var(--space-xl);
    }

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

    .nav-toggle {
        display: flex;
    }

    .theme-toggle {
        margin-left: auto;
        margin-right: var(--space-md);
    }

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

    .hero-visual {
        margin-top: var(--space-3xl);
    }

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

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

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

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

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

@media (max-width: 480px) {
    .hero-title {
        font-size: 2rem;
    }

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

    .section-title {
        font-size: 1.75rem;
    }

    .container {
        padding: 0 var(--space-md);
    }
}