/* ===================================
   CSS Variables & Reset
   =================================== */
:root {
    /* Light Mode Colors */
    --primary: #667eea;
    --primary-dark: #5568d3;
    --secondary: #764ba2;
    --accent: #f093fb;
    --success: #10b981;
    --warning: #f59e0b;
    --danger: #ef4444;
    
    --bg-primary: #ffffff;
    --bg-secondary: #f9fafb;
    --bg-tertiary: #f3f4f6;
    
    --text-primary: #1f2937;
    --text-secondary: #6b7280;
    --text-tertiary: #9ca3af;
    
    --border-color: #e5e7eb;
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.07);
    --shadow-lg: 0 10px 15px rgba(0, 0, 0, 0.1);
    --shadow-xl: 0 20px 25px rgba(0, 0, 0, 0.15);
    
    --gradient-primary: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --gradient-secondary: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
    --gradient-success: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%);
    
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-fast: all 0.15s ease;
    --transition-slow: all 0.5s ease;
    
    --border-radius-sm: 8px;
    --border-radius-md: 12px;
    --border-radius-lg: 16px;
    --border-radius-xl: 24px;
    
    --max-width: 1200px;
    --navbar-height: 70px;
}

/* Dark Mode Colors */
body.dark-mode {
    --bg-primary: #0f172a;
    --bg-secondary: #1e293b;
    --bg-tertiary: #334155;
    
    --text-primary: #f1f5f9;
    --text-secondary: #cbd5e1;
    --text-tertiary: #94a3b8;
    
    --border-color: #334155;
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 10px 15px rgba(0, 0, 0, 0.5);
    --shadow-xl: 0 20px 25px rgba(0, 0, 0, 0.6);
}

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

html {
    scroll-behavior: smooth;
    overflow-x: hidden;
}

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

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

a {
    text-decoration: none;
    color: inherit;
    transition: var(--transition-fast);
}

ul {
    list-style: none;
}

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

/* ===================================
   Utility Classes
   =================================== */
.container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 20px;
}

.gradient-text {
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 12px 28px;
    border-radius: var(--border-radius-md);
    font-weight: 600;
    font-size: 16px;
    transition: var(--transition);
    position: relative;
    overflow: hidden;
}

.btn::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(255, 255, 255, 0.1);
    transform: translateX(-100%);
    transition: var(--transition);
}

.btn:hover::before {
    transform: translateX(0);
}

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

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

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

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

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

.section-header {
    text-align: center;
    margin-bottom: 60px;
}

.section-tag {
    display: inline-block;
    padding: 8px 20px;
    background: var(--bg-tertiary);
    color: var(--primary);
    border-radius: 50px;
    font-size: 14px;
    font-weight: 600;
    margin-bottom: 16px;
    text-transform: uppercase;
    letter-spacing: 1px;
}

.section-title {
    font-size: 48px;
    font-weight: 800;
    color: var(--text-primary);
    margin-bottom: 16px;
}

.tag {
    display: inline-block;
    padding: 6px 14px;
    background: var(--bg-tertiary);
    color: var(--text-secondary);
    border-radius: 50px;
    font-size: 12px;
    font-weight: 500;
    margin: 4px;
}

/* ===================================
   Navigation
   =================================== */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    z-index: 1000;
    background: var(--bg-primary);
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
}

.navbar.scrolled {
    box-shadow: var(--shadow-md);
    backdrop-filter: blur(10px);
    background: rgba(255, 255, 255, 0.9);
}

body.dark-mode .navbar.scrolled {
    background: rgba(15, 23, 42, 0.9);
}

.nav-wrapper {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: var(--navbar-height);
}

.logo {
    font-size: 28px;
    font-weight: 800;
    color: var(--text-primary);
}

.logo .dot {
    color: var(--primary);
    font-size: 36px;
}

.nav-menu {
    display: flex;
    gap: 32px;
}

.nav-link {
    color: var(--text-secondary);
    font-weight: 500;
    font-size: 15px;
    position: relative;
}

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

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

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

.nav-icons {
    display: flex;
    align-items: center;
    gap: 16px;
}

.theme-toggle {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background: var(--bg-tertiary);
    color: var(--text-primary);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 18px;
    transition: var(--transition);
}

.theme-toggle:hover {
    background: var(--primary);
    color: white;
    transform: rotate(180deg);
}

.mobile-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    width: 30px;
    height: 30px;
}

.mobile-toggle span {
    width: 100%;
    height: 3px;
    background: var(--text-primary);
    border-radius: 3px;
    transition: var(--transition);
}

.mobile-toggle.active span:nth-child(1) {
    transform: rotate(45deg) translate(7px, 7px);
}

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

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

/* ===================================
   Hero Section
   =================================== */
.hero {
    padding: 150px 0 100px;
    position: relative;
    overflow: hidden;
    min-height: 100vh;
    display: flex;
    align-items: center;
}

.hero-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
    position: relative;
    z-index: 2;
}

.hero-title {
    font-size: 56px;
    font-weight: 900;
    line-height: 1.2;
    margin-bottom: 16px;
    animation: fadeInUp 0.8s ease;
}

.hero-subtitle {
    font-size: 28px;
    color: var(--text-secondary);
    margin-bottom: 24px;
    animation: fadeInUp 0.8s ease 0.2s backwards;
}

.hero-description {
    font-size: 18px;
    color: var(--text-secondary);
    margin-bottom: 32px;
    line-height: 1.8;
    animation: fadeInUp 0.8s ease 0.4s backwards;
}

.hero-buttons {
    display: flex;
    gap: 16px;
    margin-bottom: 32px;
    animation: fadeInUp 0.8s ease 0.6s backwards;
}

.social-links {
    display: flex;
    gap: 16px;
    animation: fadeInUp 0.8s ease 0.8s backwards;
}

.social-links a {
    width: 48px;
    height: 48px;
    border-radius: 50%;
    background: var(--bg-tertiary);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 20px;
    color: var(--text-secondary);
    transition: var(--transition);
}

.social-links a:hover {
    background: var(--gradient-primary);
    color: white;
    transform: translateY(-5px);
}

.hero-image {
    position: relative;
    animation: fadeInRight 1s ease;
}

.image-wrapper {
    position: relative;
    border-radius: var(--border-radius-xl);
    overflow: hidden;
}

.image-placeholder {
    width: 100%;
    aspect-ratio: 1;
    background: var(--gradient-primary);
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: var(--border-radius-xl);
}

.image-placeholder i {
    font-size: 200px;
    color: rgba(255, 255, 255, 0.3);
}

.hero-shapes {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    overflow: hidden;
    z-index: 1;
}

.shape {
    position: absolute;
    border-radius: 50%;
    filter: blur(60px);
    opacity: 0.3;
    animation: float 6s ease-in-out infinite;
}

.shape-1 {
    width: 400px;
    height: 400px;
    background: var(--primary);
    top: -200px;
    right: -200px;
}

.shape-2 {
    width: 300px;
    height: 300px;
    background: var(--secondary);
    bottom: -150px;
    left: -150px;
    animation-delay: 2s;
}

.shape-3 {
    width: 250px;
    height: 250px;
    background: var(--accent);
    top: 50%;
    right: 10%;
    animation-delay: 4s;
}

/* ===================================
   About Section
   =================================== */
.about {
    padding: 100px 0;
    background: var(--bg-secondary);
}

.about-content {
    max-width: 900px;
    margin: 0 auto;
}

.about-text p {
    font-size: 18px;
    color: var(--text-secondary);
    margin-bottom: 20px;
    line-height: 1.8;
}

.about-stats {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 40px;
    margin-top: 60px;
}

.stat-item {
    text-align: center;
}

.stat-number {
    font-size: 48px;
    font-weight: 900;
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: 8px;
}

.stat-label {
    font-size: 16px;
    color: var(--text-secondary);
}

/* ===================================
   Skills Section
   =================================== */
.skills {
    padding: 100px 0;
}

.skills-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 30px;
}

.skill-card {
    background: var(--bg-secondary);
    padding: 40px;
    border-radius: var(--border-radius-lg);
    transition: var(--transition);
    border: 1px solid var(--border-color);
}

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

.skill-icon {
    width: 70px;
    height: 70px;
    border-radius: var(--border-radius-md);
    background: var(--gradient-primary);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 32px;
    color: white;
    margin-bottom: 24px;
}

.skill-card h3 {
    font-size: 22px;
    margin-bottom: 12px;
    color: var(--text-primary);
}

.skill-card p {
    color: var(--text-secondary);
    margin-bottom: 20px;
    line-height: 1.6;
}

.skill-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
}

/* ===================================
   Projects Section
   =================================== */
.projects {
    padding: 100px 0;
    background: var(--bg-secondary);
}

.projects-filter {
    display: flex;
    justify-content: center;
    gap: 12px;
    margin-bottom: 60px;
    flex-wrap: wrap;
}

.filter-btn {
    padding: 10px 24px;
    border-radius: 50px;
    background: var(--bg-primary);
    color: var(--text-secondary);
    font-weight: 500;
    transition: var(--transition);
    border: 2px solid var(--border-color);
    cursor: pointer;
    font-family: inherit;
    font-size: 14px;
}

.filter-btn:hover {
    border-color: var(--primary);
    color: var(--primary);
    transform: translateY(-2px);
}

.filter-btn.active {
    background: var(--gradient-primary);
    color: white;
    border-color: transparent;
    transform: translateY(-2px);
}

.projects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(350px, 1fr));
    gap: 30px;
}

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

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

.project-image {
    position: relative;
    overflow: hidden;
    aspect-ratio: 16/10;
}

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

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

.project-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(102, 126, 234, 0.9);
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 20px;
    opacity: 0;
    transition: var(--transition);
}

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

.project-link {
    width: 50px;
    height: 50px;
    border-radius: 50%;
    background: white;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--primary);
    font-size: 20px;
    transition: var(--transition);
}

.project-link:hover {
    transform: scale(1.2) rotate(360deg);
}

.project-info {
    padding: 30px;
}

.project-tags {
    margin-bottom: 16px;
}

.project-title {
    font-size: 22px;
    margin-bottom: 12px;
    color: var(--text-primary);
}

.project-description {
    color: var(--text-secondary);
    line-height: 1.6;
}

/* ===================================
   Contact Section
   =================================== */
.contact {
    padding: 100px 0;
}

.contact-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: start;
}

.contact-info h3 {
    font-size: 32px;
    margin-bottom: 16px;
    color: var(--text-primary);
}

.contact-info > p {
    font-size: 18px;
    color: var(--text-secondary);
    margin-bottom: 40px;
    line-height: 1.8;
}

.contact-items {
    display: flex;
    flex-direction: column;
    gap: 30px;
}

.contact-item {
    display: flex;
    gap: 20px;
    align-items: start;
}

.contact-icon {
    width: 60px;
    height: 60px;
    border-radius: var(--border-radius-md);
    background: var(--gradient-primary);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 24px;
    color: white;
    flex-shrink: 0;
}

.contact-text h4 {
    font-size: 18px;
    margin-bottom: 4px;
    color: var(--text-primary);
}

.contact-text p {
    color: var(--text-secondary);
    font-size: 16px;
}

.contact-form {
    background: var(--bg-secondary);
    padding: 40px;
    border-radius: var(--border-radius-lg);
    border: 1px solid var(--border-color);
}

.form-group {
    margin-bottom: 24px;
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 16px 20px;
    border: 2px solid var(--border-color);
    border-radius: var(--border-radius-md);
    background: var(--bg-primary);
    color: var(--text-primary);
    font-family: inherit;
    font-size: 16px;
    transition: var(--transition);
}

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

.form-group textarea {
    resize: vertical;
    min-height: 120px;
}

/* ===================================
   Footer
   =================================== */
.footer {
    background: var(--bg-secondary);
    padding: 60px 0 30px;
    border-top: 1px solid var(--border-color);
}

.footer-content {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr;
    gap: 40px;
    margin-bottom: 40px;
}

.footer-logo {
    font-size: 28px;
    font-weight: 800;
    color: var(--text-primary);
    margin-bottom: 12px;
    display: inline-block;
}

.footer-left p {
    color: var(--text-secondary);
    font-size: 16px;
}

.footer-links {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.footer-links a {
    color: var(--text-secondary);
    font-size: 15px;
    transition: var(--transition);
}

.footer-links a:hover {
    color: var(--primary);
    transform: translateX(5px);
}

.footer-social {
    display: flex;
    gap: 12px;
}

.footer-social a {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background: var(--bg-tertiary);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-secondary);
    transition: var(--transition);
}

.footer-social a:hover {
    background: var(--gradient-primary);
    color: white;
    transform: translateY(-5px);
}

.footer-bottom {
    text-align: center;
    padding-top: 30px;
    border-top: 1px solid var(--border-color);
}

.footer-bottom p {
    color: var(--text-secondary);
    font-size: 14px;
}

/* ===================================
   Back to Top Button
   =================================== */
.back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 50px;
    height: 50px;
    border-radius: 50%;
    background: var(--gradient-primary);
    color: white;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 20px;
    opacity: 0;
    visibility: hidden;
    transition: var(--transition);
    z-index: 999;
}

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

.back-to-top:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

/* ===================================
   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 float {
    0%, 100% {
        transform: translateY(0) scale(1);
    }
    50% {
        transform: translateY(-30px) scale(1.05);
    }
}

/* ===================================
   Responsive Design
   =================================== */
@media (max-width: 1024px) {
    .section-title {
        font-size: 40px;
    }
    
    .hero-title {
        font-size: 48px;
    }
    
    .hero-content {
        grid-template-columns: 1fr;
        gap: 40px;
    }
    
    .contact-content {
        grid-template-columns: 1fr;
    }
    
    .footer-content {
        grid-template-columns: 1fr;
        text-align: center;
    }
    
    .footer-links,
    .footer-social {
        justify-content: center;
    }
}

@media (max-width: 768px) {
    .mobile-toggle {
        display: flex;
    }
    
    .nav-menu {
        position: fixed;
        top: var(--navbar-height);
        left: 0;
        width: 100%;
        height: calc(100vh - var(--navbar-height));
        background: var(--bg-primary);
        flex-direction: column;
        align-items: center;
        justify-content: center;
        gap: 30px;
        transform: translateX(-100%);
        transition: var(--transition);
        box-shadow: var(--shadow-lg);
    }
    
    .nav-menu.active {
        transform: translateX(0);
    }
    
    .hero {
        padding: 120px 0 80px;
    }
    
    .hero-title {
        font-size: 40px;
    }
    
    .hero-subtitle {
        font-size: 22px;
    }
    
    .hero-buttons {
        flex-direction: column;
    }
    
    .section-title {
        font-size: 32px;
    }
    
    .about-stats {
        grid-template-columns: 1fr;
        gap: 30px;
    }
    
    .projects-grid {
        grid-template-columns: 1fr;
    }
    
    .skills-grid {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 480px) {
    .hero-title {
        font-size: 32px;
    }
    
    .section-title {
        font-size: 28px;
    }
    
    .btn {
        padding: 10px 20px;
        font-size: 14px;
    }
    
    .contact-form {
        padding: 24px;
    }
}