/* ========================================
   Uğur Kaya Portfolio - Modern Dark Theme
   ======================================== */

/* CSS Variables */
:root {
    /* Colors - Dark Theme (Default) */
    --bg-primary: #050505;
    --bg-secondary: #0a0a0a;
    --bg-tertiary: #111111;
    --bg-card: #161616;
    
    --text-primary: #ffffff;
    --text-secondary: #a0a0a0;
    --text-muted: #666666;
    
    --accent: #C7FC77;
    --accent-hover: #d4ff8c;
    --accent-rgb: 199, 252, 119;
    
    --border: #222222;
    --border-hover: #333333;
    
    --success: #22c55e;
    --warning: #eab308;
    --error: #ef4444;
    --info: #3b82f6;
    
    /* Typography */
    --font-primary: 'Inter', -apple-system, BlinkMacSystemFont, 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: 0.15s ease;
    --transition-normal: 0.3s ease;
    --transition-slow: 0.5s ease;
    
    /* Shadows */
    --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-glow: 0 0 20px rgba(var(--accent-rgb), 0.3);
    
    /* Border Radius */
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 12px;
    --radius-xl: 16px;
    --radius-full: 9999px;
}

/* Light Theme */
[data-theme="light"] {
    --bg-primary: #ffffff;
    --bg-secondary: #f8f9fa;
    --bg-tertiary: #e9ecef;
    --bg-card: #ffffff;
    
    --text-primary: #1a1a1a;
    --text-secondary: #495057;
    --text-muted: #6c757d;
    
    --border: #dee2e6;
    --border-hover: #ced4da;
    
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.1);
    --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px rgba(0, 0, 0, 0.1);
}

/* Reset & Base */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

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

body {
    font-family: var(--font-primary);
    background-color: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
    overflow-x: hidden;
}

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

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

/* Container */
.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--space-lg);
}

/* Loading Screen */
#loading-screen {
    position: fixed;
    inset: 0;
    background: var(--bg-primary);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 9999;
    transition: opacity var(--transition-slow), visibility var(--transition-slow);
}

#loading-screen.hidden {
    opacity: 0;
    visibility: hidden;
}

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

.loading-code {
    font-family: var(--font-mono);
    font-size: 4rem;
    color: var(--accent);
    animation: pulse 1.5s ease-in-out infinite;
}

.loading-bar {
    width: 200px;
    height: 3px;
    background: var(--border);
    border-radius: var(--radius-full);
    margin-top: var(--space-lg);
    overflow: hidden;
}

.loading-progress {
    height: 100%;
    background: var(--accent);
    border-radius: var(--radius-full);
    animation: loading 2s ease-in-out infinite;
}

@keyframes loading {
    0% { width: 0; margin-left: 0; }
    50% { width: 100%; margin-left: 0; }
    100% { width: 0; margin-left: 100%; }
}

@keyframes pulse {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.5; }
}

/* Navigation */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: rgba(5, 5, 5, 0.8);
    backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--border);
    transition: all var(--transition-normal);
}

.navbar.scrolled {
    background: rgba(5, 5, 5, 0.95);
    box-shadow: var(--shadow-md);
}

[data-theme="light"] .navbar {
    background: rgba(255, 255, 255, 0.8);
}

.navbar .container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 70px;
}

.logo {
    display: flex;
    align-items: center;
    gap: var(--space-xs);
    font-family: var(--font-mono);
    font-size: 1.25rem;
    font-weight: 700;
}

.logo-bracket {
    color: var(--accent);
}

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

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

.nav-link {
    position: relative;
    font-size: 0.9rem;
    font-weight: 500;
    color: var(--text-secondary);
    padding: var(--space-sm) 0;
    transition: color var(--transition-normal);
}

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

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

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

.nav-actions {
    display: flex;
    align-items: center;
    gap: var(--space-md);
}

.theme-toggle {
    width: 40px;
    height: 40px;
    border-radius: var(--radius-md);
    border: 1px solid var(--border);
    background: transparent;
    color: var(--text-secondary);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all var(--transition-normal);
}

.theme-toggle:hover {
    border-color: var(--accent);
    color: var(--accent);
}

.theme-toggle .fa-sun {
    display: none;
}

.theme-toggle .fa-moon {
    display: block;
}

[data-theme="light"] .theme-toggle .fa-sun {
    display: block;
}

[data-theme="light"] .theme-toggle .fa-moon {
    display: none;
}

.nav-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: var(--space-sm);
}

.nav-toggle span {
    display: block;
    width: 25px;
    height: 2px;
    background: var(--text-primary);
    transition: all var(--transition-normal);
}

/* Main Content */
.main-content {
    padding-top: 70px;
    min-height: calc(100vh - 70px);
}

/* Hero Section */
.hero {
    min-height: calc(100vh - 70px);
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    overflow: hidden;
    padding: var(--space-3xl) 0;
}

.hero-bg {
    position: absolute;
    inset: 0;
    overflow: hidden;
}

.hero-particles {
    position: absolute;
    inset: 0;
}

.particle {
    position: absolute;
    width: 4px;
    height: 4px;
    background: var(--accent);
    border-radius: 50%;
    opacity: 0.3;
    animation: float 6s ease-in-out infinite;
}

@keyframes float {
    0%, 100% { transform: translateY(0) translateX(0); }
    25% { transform: translateY(-20px) translateX(10px); }
    50% { transform: translateY(-10px) translateX(-10px); }
    75% { transform: translateY(-30px) translateX(5px); }
}

.hero-content {
    text-align: center;
    position: relative;
    z-index: 1;
    max-width: 800px;
    padding: 0 var(--space-lg);
}

.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: var(--space-sm);
    padding: var(--space-sm) var(--space-md);
    background: rgba(var(--accent-rgb), 0.1);
    border: 1px solid rgba(var(--accent-rgb), 0.2);
    border-radius: var(--radius-full);
    font-family: var(--font-mono);
    font-size: 0.85rem;
    color: var(--accent);
    margin-bottom: var(--space-xl);
}

.hero-badge .dot {
    width: 8px;
    height: 8px;
    background: var(--accent);
    border-radius: 50%;
    animation: blink 2s infinite;
}

@keyframes blink {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.3; }
}

.hero-title {
    font-size: clamp(2.5rem, 8vw, 4.5rem);
    font-weight: 700;
    line-height: 1.1;
    margin-bottom: var(--space-lg);
}

.hero-title .highlight {
    color: var(--accent);
}

.hero-subtitle {
    font-size: clamp(1rem, 2.5vw, 1.25rem);
    color: var(--text-secondary);
    margin-bottom: var(--space-xl);
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

.hero-tech {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: var(--space-md);
    margin-bottom: var(--space-2xl);
}

.tech-tag {
    font-family: var(--font-mono);
    font-size: 0.85rem;
    color: var(--text-secondary);
    padding: var(--space-sm) var(--space-md);
    background: var(--bg-tertiary);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    transition: all var(--transition-normal);
}

.tech-tag:hover {
    border-color: var(--accent);
    color: var(--accent);
}

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

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-sm);
    padding: var(--space-md) var(--space-xl);
    font-family: var(--font-mono);
    font-size: 0.9rem;
    font-weight: 600;
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all var(--transition-normal);
    border: none;
}

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

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

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

.btn-secondary:hover {
    border-color: var(--accent);
    color: var(--accent);
}

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

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

/* Section Styles */
.section {
    padding: var(--space-3xl) 0;
}

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

.section-label {
    display: inline-block;
    font-family: var(--font-mono);
    font-size: 0.85rem;
    color: var(--accent);
    text-transform: uppercase;
    letter-spacing: 2px;
    margin-bottom: var(--space-md);
}

.section-title {
    font-size: clamp(2rem, 5vw, 3rem);
    font-weight: 700;
    margin-bottom: var(--space-md);
}

.section-description {
    font-size: 1.1rem;
    color: var(--text-secondary);
    max-width: 600px;
    margin: 0 auto;
}

/* Cards */
.card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    overflow: hidden;
    transition: all var(--transition-normal);
}

.card:hover {
    border-color: var(--border-hover);
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

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

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

.card:hover .card-image img {
    transform: scale(1.05);
}

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

.card-category {
    font-family: var(--font-mono);
    font-size: 0.75rem;
    color: var(--accent);
    text-transform: uppercase;
    letter-spacing: 1px;
    margin-bottom: var(--space-sm);
}

.card-title {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: var(--space-sm);
}

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

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

.card-tag {
    font-family: var(--font-mono);
    font-size: 0.75rem;
    color: var(--text-muted);
    padding: var(--space-xs) var(--space-sm);
    background: var(--bg-tertiary);
    border-radius: var(--radius-sm);
}

/* Grid */
.grid {
    display: grid;
    gap: var(--space-xl);
}

.grid-2 {
    grid-template-columns: repeat(2, 1fr);
}

.grid-3 {
    grid-template-columns: repeat(3, 1fr);
}

.grid-4 {
    grid-template-columns: repeat(4, 1fr);
}

/* Skills */
.skill-bar {
    margin-bottom: var(--space-lg);
}

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

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

.skill-percent {
    font-family: var(--font-mono);
    font-size: 0.85rem;
    color: var(--accent);
}

.skill-progress {
    height: 8px;
    background: var(--bg-tertiary);
    border-radius: var(--radius-full);
    overflow: hidden;
}

.skill-progress-bar {
    height: 100%;
    background: linear-gradient(90deg, var(--accent), var(--accent-hover));
    border-radius: var(--radius-full);
    transition: width 1s ease-out;
}

/* Forms */
.form-group {
    margin-bottom: var(--space-lg);
}

.form-label {
    display: block;
    font-size: 0.9rem;
    font-weight: 500;
    margin-bottom: var(--space-sm);
}

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

.form-input:focus,
.form-textarea:focus {
    outline: none;
    border-color: var(--accent);
    box-shadow: 0 0 0 3px rgba(var(--accent-rgb), 0.1);
}

.form-input::placeholder,
.form-textarea::placeholder {
    color: var(--text-muted);
}

.form-textarea {
    min-height: 150px;
    resize: vertical;
}

/* Footer */
.footer {
    background: var(--bg-tertiary);
    border-top: 1px solid var(--border);
    padding: var(--space-3xl) 0 var(--space-xl);
}

.footer-grid {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1.5fr;
    gap: var(--space-2xl);
    margin-bottom: var(--space-2xl);
}

.footer-logo {
    display: inline-flex;
    align-items: center;
    gap: var(--space-xs);
    font-family: var(--font-mono);
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: var(--space-md);
}

.footer-description {
    color: var(--text-secondary);
    font-size: 0.9rem;
    margin-bottom: var(--space-lg);
}

.footer-social {
    display: flex;
    gap: var(--space-md);
}

.footer-social a {
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    color: var(--text-secondary);
    transition: all var(--transition-normal);
}

.footer-social a:hover {
    border-color: var(--accent);
    color: var(--accent);
    transform: translateY(-2px);
}

.footer-links h4,
.footer-contact h4 {
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: var(--space-lg);
}

.footer-links ul,
.footer-contact ul {
    list-style: none;
}

.footer-links li,
.footer-contact li {
    margin-bottom: var(--space-sm);
}

.footer-links a {
    color: var(--text-secondary);
    font-size: 0.9rem;
    transition: color var(--transition-normal);
}

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

.footer-contact li {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    color: var(--text-secondary);
    font-size: 0.9rem;
}

.footer-contact i {
    color: var(--accent);
    width: 20px;
}

.footer-bottom {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-top: var(--space-xl);
    border-top: 1px solid var(--border);
    font-size: 0.85rem;
    color: var(--text-muted);
}

.footer-code {
    font-family: var(--font-mono);
}

.code-tag {
    color: var(--accent);
}

.code-string {
    color: #22c55e;
}

/* Scroll to Top */
.scroll-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 45px;
    height: 45px;
    background: var(--accent);
    color: var(--bg-primary);
    border: none;
    border-radius: var(--radius-md);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    visibility: hidden;
    transform: translateY(20px);
    transition: all var(--transition-normal);
    z-index: 999;
}

.scroll-top.visible {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.scroll-top:hover {
    background: var(--accent-hover);
    transform: translateY(-4px);
}

/* Alerts */
.alert {
    padding: var(--space-md) var(--space-lg);
    border-radius: var(--radius-md);
    margin-bottom: var(--space-lg);
}

.alert-success {
    background: rgba(34, 197, 94, 0.1);
    border: 1px solid rgba(34, 197, 94, 0.3);
    color: var(--success);
}

.alert-error {
    background: rgba(239, 68, 68, 0.1);
    border: 1px solid rgba(239, 68, 68, 0.3);
    color: var(--error);
}

/* Responsive */
@media (max-width: 1024px) {
    .grid-4 {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .footer-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 768px) {
    .nav-menu {
        position: fixed;
        top: 70px;
        left: 0;
        right: 0;
        background: var(--bg-primary);
        flex-direction: column;
        padding: var(--space-xl);
        gap: var(--space-md);
        border-bottom: 1px solid var(--border);
        transform: translateY(-100%);
        opacity: 0;
        visibility: hidden;
        transition: all var(--transition-normal);
    }
    
    .nav-menu.active {
        transform: translateY(0);
        opacity: 1;
        visibility: visible;
    }
    
    .nav-toggle {
        display: flex;
    }
    
    .grid-2,
    .grid-3,
    .grid-4 {
        grid-template-columns: 1fr;
    }
    
    .footer-grid {
        grid-template-columns: 1fr;
        gap: var(--space-xl);
    }
    
    .footer-bottom {
        flex-direction: column;
        gap: var(--space-md);
        text-align: center;
    }
    
    .hero-cta {
        flex-direction: column;
    }
    
    .btn {
        width: 100%;
    }
}

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

.animate-fade-in {
    animation: fadeIn 0.6s ease-out forwards;
}

/* Utility Classes */
.text-center { text-align: center; }
.text-left { text-align: left; }
.text-right { text-align: right; }

.mt-1 { margin-top: var(--space-sm); }
.mt-2 { margin-top: var(--space-md); }
.mt-3 { margin-top: var(--space-lg); }
.mt-4 { margin-top: var(--space-xl); }

.mb-1 { margin-bottom: var(--space-sm); }
.mb-2 { margin-bottom: var(--space-md); }
.mb-3 { margin-bottom: var(--space-lg); }
.mb-4 { margin-bottom: var(--space-xl); }

.hidden { display: none !important; }
.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}