/* ===================================
   CSS Variables & Reset
   =================================== */

:root {
    /* Colors */
    --primary-color: #6366f1;
    --primary-dark: #4f46e5;
    --primary-light: #818cf8;
    --secondary-color: #ec4899;
    --text-primary: #1f2937;
    --text-secondary: #6b7280;
    --text-light: #9ca3af;
    --bg-primary: #ffffff;
    --bg-secondary: #f9fafb;
    --bg-accent: #f3f4f6;
    --border-color: #e5e7eb;
    --success-color: #10b981;
    --warning-color: #f59e0b;
    
    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;
    --spacing-2xl: 4rem;
    --spacing-3xl: 6rem;
    
    /* Typography */
    --font-primary: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --font-heading: 'Poppins', var(--font-primary);
    --font-size-sm: 0.875rem;
    --font-size-base: 1rem;
    --font-size-lg: 1.125rem;
    --font-size-xl: 1.25rem;
    --font-size-2xl: 1.5rem;
    --font-size-3xl: 2rem;
    --font-size-4xl: 2.5rem;
    --font-size-5xl: 3rem;
    
    /* Effects */
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
    --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.1), 0 8px 10px -6px rgb(0 0 0 / 0.1);
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
    
    /* Transitions */
    --transition-fast: 150ms ease-in-out;
    --transition-base: 250ms ease-in-out;
    --transition-slow: 350ms ease-in-out;
}

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

html {
    scroll-behavior: smooth;
}

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

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

/* ===================================
   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(--border-color);
    z-index: 1000;
    transition: all var(--transition-base);
}

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

.navbar .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-top: var(--spacing-sm);
    padding-bottom: var(--spacing-sm);
}

.logo {
    font-family: var(--font-heading);
    font-size: var(--font-size-2xl);
    font-weight: 700;
    color: var(--primary-color);
    text-decoration: none;
    transition: transform var(--transition-fast);
}

.logo:hover {
    transform: scale(1.05);
}

.nav-links {
    display: flex;
    list-style: none;
    gap: var(--spacing-lg);
}

.nav-links a {
    color: var(--text-primary);
    text-decoration: none;
    font-weight: 500;
    position: relative;
    transition: color var(--transition-fast);
}

.nav-links a::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--primary-color);
    transition: width var(--transition-base);
}

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

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

/* ===================================
   Hero Section
   =================================== */

.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    padding-top: 80px;
    background: linear-gradient(135deg, #f9fafb 0%, #ffffff 50%, #f3f4f6 100%);
}

.hero-content {
    text-align: center;
    max-width: 800px;
    margin: 0 auto;
}

.hero-title {
    font-family: var(--font-heading);
    font-size: var(--font-size-5xl);
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: var(--spacing-sm);
    line-height: 1.2;
}

.hero-subtitle {
    font-size: var(--font-size-2xl);
    color: var(--primary-color);
    font-weight: 600;
    margin-bottom: var(--spacing-md);
}

.hero-description {
    font-size: var(--font-size-lg);
    color: var(--text-secondary);
    margin-bottom: var(--spacing-xl);
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

.hero-cta {
    display: flex;
    gap: var(--spacing-md);
    justify-content: center;
    flex-wrap: wrap;
}

.scroll-indicator {
    position: absolute;
    bottom: var(--spacing-xl);
    left: 50%;
    transform: translateX(-50%);
    animation: bounce 2s infinite;
}

.scroll-indicator a {
    color: var(--text-secondary);
    font-size: var(--font-size-2xl);
    text-decoration: none;
    transition: color var(--transition-fast);
}

.scroll-indicator a:hover {
    color: var(--primary-color);
}

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

/* ===================================
   Buttons
   =================================== */

.btn {
    display: inline-block;
    padding: var(--spacing-sm) var(--spacing-lg);
    border-radius: var(--radius-md);
    text-decoration: none;
    font-weight: 600;
    transition: all var(--transition-base);
    border: 2px solid transparent;
    cursor: pointer;
}

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

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

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

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

.btn-disabled {
    opacity: 0.5;
    cursor: not-allowed;
    pointer-events: none;
}

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

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

.btn-link.disabled {
    color: var(--text-light);
    cursor: not-allowed;
}

/* ===================================
   Animations
   =================================== */

.fade-in {
    animation: fadeIn 0.8s ease-in-out;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.fade-in:nth-child(1) { animation-delay: 0.1s; }
.fade-in:nth-child(2) { animation-delay: 0.2s; }
.fade-in:nth-child(3) { animation-delay: 0.3s; }
.fade-in:nth-child(4) { animation-delay: 0.4s; }

/* ===================================
   Section Styling
   =================================== */

section {
    padding: var(--spacing-3xl) 0;
}

.section-header {
    text-align: center;
    margin-bottom: var(--spacing-2xl);
}

.section-header h2 {
    font-family: var(--font-heading);
    font-size: var(--font-size-4xl);
    color: var(--text-primary);
    margin-bottom: var(--spacing-sm);
}

.section-header p {
    font-size: var(--font-size-lg);
    color: var(--text-secondary);
}

/* ===================================
   Featured Project
   =================================== */

.featured-project {
    background: var(--bg-secondary);
}

.featured-card {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-2xl);
    background: white;
    border-radius: var(--radius-xl);
    padding: var(--spacing-2xl);
    box-shadow: var(--shadow-lg);
    transition: transform var(--transition-base), box-shadow var(--transition-base);
}

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

.project-badge {
    display: inline-block;
    background: var(--warning-color);
    color: white;
    padding: var(--spacing-xs) var(--spacing-sm);
    border-radius: var(--radius-sm);
    font-size: var(--font-size-sm);
    font-weight: 600;
    margin-bottom: var(--spacing-md);
}

.featured-card h3 {
    font-family: var(--font-heading);
    font-size: var(--font-size-3xl);
    color: var(--text-primary);
    margin-bottom: var(--spacing-sm);
}

.project-lead {
    font-size: var(--font-size-xl);
    color: var(--text-primary);
    font-weight: 500;
    margin-bottom: var(--spacing-md);
}

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

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

.tech-tag {
    background: var(--bg-accent);
    color: var(--primary-color);
    padding: var(--spacing-xs) var(--spacing-sm);
    border-radius: var(--radius-sm);
    font-size: var(--font-size-sm);
    font-weight: 500;
}

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

.featured-card-visual {
    display: flex;
    align-items: center;
    justify-content: center;
}

.project-placeholder {
    width: 100%;
    height: 100%;
    background: linear-gradient(135deg, var(--primary-light) 0%, var(--primary-color) 100%);
    border-radius: var(--radius-lg);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    color: white;
    min-height: 300px;
}

.project-placeholder i {
    font-size: 4rem;
    margin-bottom: var(--spacing-md);
    opacity: 0.9;
}

.project-placeholder p {
    font-size: var(--font-size-lg);
    font-weight: 500;
}

/* ===================================
   Projects Grid
   =================================== */

.projects {
    background: white;
}

.projects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: var(--spacing-xl);
}

.project-card {
    background: white;
    border: 2px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    transition: all var(--transition-base);
}

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

.project-card-placeholder {
    opacity: 0.7;
}

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

.project-icon {
    font-size: var(--font-size-3xl);
    color: var(--primary-color);
}

.project-badge-small {
    background: var(--warning-color);
    color: white;
    padding: 4px 12px;
    border-radius: var(--radius-sm);
    font-size: 0.75rem;
    font-weight: 600;
}

.project-card h3 {
    font-family: var(--font-heading);
    font-size: var(--font-size-2xl);
    color: var(--text-primary);
    margin-bottom: var(--spacing-sm);
}

.project-summary {
    color: var(--text-secondary);
    line-height: 1.6;
    margin-bottom: var(--spacing-md);
    min-height: 100px;
}

.tech-tag-small {
    background: var(--bg-accent);
    color: var(--text-secondary);
    padding: 4px 12px;
    border-radius: var(--radius-sm);
    font-size: var(--font-size-sm);
    font-weight: 500;
}

.project-card-footer {
    margin-top: var(--spacing-md);
    padding-top: var(--spacing-md);
    border-top: 1px solid var(--border-color);
}

/* ===================================
   About Section
   =================================== */

.about {
    background: var(--bg-secondary);
}

.about-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-2xl);
}

.about-text .lead {
    font-size: var(--font-size-xl);
    color: var(--text-primary);
    font-weight: 500;
    margin-bottom: var(--spacing-md);
}

.about-text p {
    color: var(--text-secondary);
    line-height: 1.7;
    margin-bottom: var(--spacing-md);
}

.skills h3 {
    font-family: var(--font-heading);
    font-size: var(--font-size-2xl);
    color: var(--text-primary);
    margin-bottom: var(--spacing-md);
}

.skills-grid {
    display: grid;
    gap: var(--spacing-lg);
}

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

.skill-category h4 {
    color: var(--primary-color);
    font-size: var(--font-size-lg);
    margin-bottom: var(--spacing-sm);
    font-weight: 600;
}

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

.skill-category li {
    color: var(--text-secondary);
    padding: var(--spacing-xs) 0;
    position: relative;
    padding-left: var(--spacing-md);
}

.skill-category li::before {
    content: '▹';
    position: absolute;
    left: 0;
    color: var(--primary-color);
    font-weight: bold;
}

/* ===================================
   Contact Section
   =================================== */

.contact {
    background: white;
}

.contact-links {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--spacing-xl);
    max-width: 900px;
    margin: 0 auto;
}

.contact-card {
    background: var(--bg-secondary);
    padding: var(--spacing-xl);
    border-radius: var(--radius-lg);
    text-align: center;
    text-decoration: none;
    transition: all var(--transition-base);
    border: 2px solid transparent;
}

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

.contact-card i {
    font-size: 3rem;
    color: var(--primary-color);
    margin-bottom: var(--spacing-md);
}

.contact-card h3 {
    font-family: var(--font-heading);
    font-size: var(--font-size-xl);
    color: var(--text-primary);
    margin-bottom: var(--spacing-xs);
}

.contact-card p {
    color: var(--text-secondary);
}

/* ===================================
   Footer
   =================================== */

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

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

/* ===================================
   Responsive Design
   =================================== */

@media (max-width: 1024px) {
    .hero-title {
        font-size: var(--font-size-4xl);
    }
    
    .featured-card {
        grid-template-columns: 1fr;
    }
    
    .about-content {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 768px) {
    .container {
        padding: 0 var(--spacing-md);
    }
    
    .nav-links {
        gap: var(--spacing-md);
    }
    
    .hero-title {
        font-size: var(--font-size-3xl);
    }
    
    .hero-subtitle {
        font-size: var(--font-size-xl);
    }
    
    .hero-cta {
        flex-direction: column;
        align-items: center;
    }
    
    .btn {
        width: 100%;
        max-width: 300px;
        text-align: center;
    }
    
    .section-header h2 {
        font-size: var(--font-size-3xl);
    }
    
    .projects-grid {
        grid-template-columns: 1fr;
    }
    
    .contact-links {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 480px) {
    .navbar .container {
        flex-direction: column;
        gap: var(--spacing-sm);
    }
    
    .nav-links {
        gap: var(--spacing-sm);
    }
    
    .hero-title {
        font-size: var(--font-size-2xl);
    }
    
    section {
        padding: var(--spacing-2xl) 0;
    }
    
    .featured-card {
        padding: var(--spacing-lg);
    }
}