/* ============================================================================
   CSS VARIABLES & RESET
   ============================================================================ */

:root {
    /* Colors */
    --color-primary: #3b82f6;
    --color-primary-dark: #2563eb;
    --color-secondary: #8b5cf6;
    --color-accent: #10b981;
    
    /* Dark Theme */
    --color-bg: #0f172a;
    --color-bg-secondary: #1e293b;
    --color-bg-tertiary: #334155;
    --color-text: #f1f5f9;
    --color-text-secondary: #cbd5e1;
    --color-text-muted: #94a3b8;
    
    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;
    --spacing-2xl: 4rem;
    
    /* Typography */
    --font-sans: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    --font-mono: 'Courier New', monospace;
    
    /* Border Radius */
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
    
    /* Shadows */
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1);
    
    /* Transitions */
    --transition-fast: 150ms ease;
    --transition-base: 200ms ease;
    --transition-slow: 300ms ease;
}

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

html {
    scroll-behavior: smooth;
}

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

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

a {
    color: var(--color-primary);
    text-decoration: none;
    transition: color var(--transition-base);
}

a:hover {
    color: var(--color-primary-dark);
}

/* ============================================================================
   LAYOUT
   ============================================================================ */

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

/* ============================================================================
   NAVBAR
   ============================================================================ */

.navbar {
    background-color: var(--color-bg-secondary);
    padding: var(--spacing-md) 0;
    position: sticky;
    top: 0;
    z-index: 1000;
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--color-bg-tertiary);
}

.navbar .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.navbar-brand .logo-text {
    font-size: 1.5rem;
    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;
}

.navbar-menu {
    display: flex;
    gap: var(--spacing-md);
    align-items: center;
}

.nav-link {
    color: var(--color-text-secondary);
    padding: var(--spacing-xs) var(--spacing-sm);
    border-radius: var(--radius-md);
    transition: all var(--transition-base);
}

.nav-link:hover,
.nav-link.active {
    color: var(--color-primary);
    background-color: rgba(59, 130, 246, 0.1);
}

.nav-link-admin {
    background-color: var(--color-primary);
    color: white;
    padding: var(--spacing-xs) var(--spacing-md);
}

.nav-link-admin:hover {
    background-color: var(--color-primary-dark);
    color: white;
}

.mobile-menu-toggle {
    display: none;
    flex-direction: column;
    gap: 4px;
    background: none;
    border: none;
    cursor: pointer;
}

.mobile-menu-toggle span {
    width: 25px;
    height: 3px;
    background-color: var(--color-text);
    border-radius: 2px;
    transition: all var(--transition-base);
}

@media (max-width: 768px) {
    .mobile-menu-toggle {
        display: flex;
    }
    
    .navbar-menu {
        position: fixed;
        top: 70px;
        right: -100%;
        width: 250px;
        height: calc(100vh - 70px);
        background-color: var(--color-bg-secondary);
        flex-direction: column;
        align-items: flex-start;
        padding: var(--spacing-lg);
        transition: right var(--transition-slow);
        border-left: 1px solid var(--color-bg-tertiary);
    }
    
    .navbar-menu.active {
        right: 0;
    }
}

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

.hero {
    min-height: 90vh;
    display: flex;
    align-items: center;
    padding: var(--spacing-2xl) 0;
    background: linear-gradient(135deg, var(--color-bg) 0%, var(--color-bg-secondary) 100%);
}

.hero-content {
    max-width: 800px;
}

.hero-title {
    font-size: clamp(2.5rem, 5vw, 4rem);
    font-weight: 800;
    margin-bottom: var(--spacing-md);
    line-height: 1.2;
}

.highlight {
    background: linear-gradient(135deg, var(--color-primary), var(--color-secondary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-subtitle {
    font-size: clamp(1.25rem, 3vw, 1.75rem);
    color: var(--color-text-secondary);
    margin-bottom: var(--spacing-md);
}

.hero-description {
    font-size: 1.125rem;
    color: var(--color-text-muted);
    margin-bottom: var(--spacing-xl);
    max-width: 600px;
}

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

/* ============================================================================
   SECTIONS
   ============================================================================ */

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

.section-title {
    font-size: clamp(2rem, 4vw, 2.5rem);
    font-weight: 700;
    text-align: center;
    margin-bottom: var(--spacing-lg);
}

.section-description {
    text-align: center;
    color: var(--color-text-secondary);
    margin-bottom: var(--spacing-xl);
    font-size: 1.125rem;
}

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

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

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

.about-content {
    max-width: 800px;
    margin: 0 auto;
}

.about-text p {
    font-size: 1.125rem;
    color: var(--color-text-secondary);
    margin-bottom: var(--spacing-md);
}

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

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

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

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

.skill-icon {
    font-size: 3rem;
    margin-bottom: var(--spacing-md);
}

.skill-card h3 {
    font-size: 1.25rem;
    margin-bottom: var(--spacing-sm);
}

.skill-card p {
    color: var(--color-text-muted);
}

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

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

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

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

.project-image,
.project-image-placeholder {
    width: 100%;
    height: 200px;
    object-fit: cover;
}

.project-image-placeholder {
    background-color: var(--color-bg-tertiary);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--color-text-muted);
}

.project-content {
    padding: var(--spacing-md);
}

.project-content h3 {
    font-size: 1.25rem;
    margin-bottom: var(--spacing-sm);
}

.project-content p {
    color: var(--color-text-secondary);
    margin-bottom: var(--spacing-md);
}

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

.tag {
    background-color: var(--color-bg-tertiary);
    color: var(--color-text-secondary);
    padding: 0.25rem 0.75rem;
    border-radius: var(--radius-sm);
    font-size: 0.875rem;
}

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

.project-link {
    color: var(--color-primary);
    font-size: 0.875rem;
    padding: var(--spacing-xs) var(--spacing-sm);
    border: 1px solid var(--color-primary);
    border-radius: var(--radius-sm);
    transition: all var(--transition-base);
}

.project-link:hover {
    background-color: var(--color-primary);
    color: white;
}

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

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

.contact-content {
    display: grid;
    grid-template-columns: 1fr 2fr;
    gap: var(--spacing-xl);
    max-width: 1000px;
    margin: 0 auto;
}

.contact-info {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-lg);
}

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

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

.contact-item h4 {
    margin-bottom: var(--spacing-xs);
}

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

/* ============================================================================
   FORMS
   ============================================================================ */

.contact-form,
.admin-form {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.form-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-md);
}

.form-group {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xs);
}

.form-group label {
    font-weight: 500;
    color: var(--color-text-secondary);
}

.form-group input,
.form-group textarea,
.form-group select {
    padding: var(--spacing-sm);
    background-color: var(--color-bg);
    border: 1px solid var(--color-bg-tertiary);
    border-radius: var(--radius-md);
    color: var(--color-text);
    font-family: var(--font-sans);
    font-size: 1rem;
    transition: all var(--transition-base);
}

.form-group input:focus,
.form-group textarea:focus,
.form-group select:focus {
    outline: none;
    border-color: var(--color-primary);
    box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.1);
}

.form-text {
    font-size: 0.875rem;
    color: var(--color-text-muted);
}

.error-text {
    color: #ef4444;
    font-size: 0.875rem;
}

.form-message {
    padding: var(--spacing-md);
    border-radius: var(--radius-md);
    margin-top: var(--spacing-md);
    display: none;
}

.form-message.success {
    background-color: rgba(16, 185, 129, 0.1);
    border: 1px solid var(--color-accent);
    color: var(--color-accent);
    display: block;
}

.form-message.error {
    background-color: rgba(239, 68, 68, 0.1);
    border: 1px solid #ef4444;
    color: #ef4444;
    display: block;
}

/* ============================================================================
   BUTTONS
   ============================================================================ */

.btn {
    display: inline-block;
    padding: var(--spacing-sm) var(--spacing-lg);
    border-radius: var(--radius-md);
    font-weight: 500;
    text-align: center;
    cursor: pointer;
    transition: all var(--transition-base);
    border: none;
    font-size: 1rem;
}

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

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

.btn-secondary {
    background-color: var(--color-bg-tertiary);
    color: var(--color-text);
}

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

.btn-outline {
    background-color: transparent;
    border: 1px solid var(--color-primary);
    color: var(--color-primary);
}

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

.btn-block {
    width: 100%;
}

.btn-sm {
    padding: var(--spacing-xs) var(--spacing-md);
    font-size: 0.875rem;
}

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

.footer {
    background-color: var(--color-bg-secondary);
    padding: var(--spacing-2xl) 0 var(--spacing-lg);
    border-top: 1px solid var(--color-bg-tertiary);
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--spacing-xl);
    margin-bottom: var(--spacing-xl);
}

.footer-section h3,
.footer-section h4 {
    margin-bottom: var(--spacing-md);
}

.footer-section p {
    color: var(--color-text-secondary);
    margin-bottom: var(--spacing-sm);
}

.footer-links {
    list-style: none;
}

.footer-links li {
    margin-bottom: var(--spacing-xs);
}

.footer-links a {
    color: var(--color-text-secondary);
}

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

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

.social-links a {
    color: var(--color-text-secondary);
    transition: color var(--transition-base);
}

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

.footer-bottom {
    text-align: center;
    padding-top: var(--spacing-lg);
    border-top: 1px solid var(--color-bg-tertiary);
    color: var(--color-text-muted);
}

.footer-bottom p {
    margin-bottom: var(--spacing-xs);
}

/* ============================================================================
   UTILITY CLASSES
   ============================================================================ */

.text-muted {
    color: var(--color-text-muted);
}

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

.empty-state {
    text-align: center;
    padding: var(--spacing-2xl);
    color: var(--color-text-muted);
}

/* ============================================================================
   404 ERROR PAGE
   ============================================================================ */

.error-page {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
}

.error-code {
    font-size: 8rem;
    font-weight: 900;
    background: linear-gradient(135deg, var(--color-primary), var(--color-secondary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: var(--spacing-md);
}

.error-page h2 {
    font-size: 2rem;
    margin-bottom: var(--spacing-md);
}

.error-page p {
    color: var(--color-text-secondary);
    margin-bottom: var(--spacing-xl);
}

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

@media (max-width: 768px) {
    .contact-content {
        grid-template-columns: 1fr;
    }
    
    .form-row {
        grid-template-columns: 1fr;
    }
    
    .section-header {
        flex-direction: column;
        gap: var(--spacing-md);
        align-items: flex-start;
    }
    
    .hero-cta {
        flex-direction: column;
    }
    
    .hero-cta .btn {
        width: 100%;
    }
}

@media (max-width: 480px) {
    .projects-grid {
        grid-template-columns: 1fr;
    }
    
    .skills-grid {
        grid-template-columns: 1fr;
    }
}