/* ===================================================================
   Ford Car Price Prediction - Premium Website Styles
   Glassmorphism | Dark/Light Mode | Smooth Animations
   =================================================================== */

/* ==================== CSS VARIABLES ==================== */
:root {
    /* Light Mode Colors */
    --bg-primary: #f8f9fa;
    --bg-secondary: #ffffff;
    --bg-glass: rgba(255, 255, 255, 0.7);
    --text-primary: #1a1a2e;
    --text-secondary: #4a5568;
    --text-muted: #718096;
    --accent-primary: #667eea;
    --accent-secondary: #764ba2;
    --accent-gradient: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --success: #48bb78;
    --warning: #ed8936;
    --error: #f56565;
    --border: rgba(0, 0, 0, 0.1);
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.08);
    --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.12);
    --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.16);
    --shadow-xl: 0 16px 64px rgba(0, 0, 0, 0.2);
    
    /* Typography */
    --font-primary: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Oxygen', 'Ubuntu', 'Cantarell', sans-serif;
    --font-mono: 'SF Mono', 'Monaco', 'Inconsolata', 'Fira Code', 'Consolas', monospace;
    
    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;
    --spacing-2xl: 4rem;
    
    /* Border Radius */
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-xl: 24px;
    --radius-full: 9999px;
    
    /* Transitions */
    --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-base: 250ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: 350ms cubic-bezier(0.4, 0, 0.2, 1);
    
    /* Blur */
    --blur-sm: 8px;
    --blur-md: 16px;
    --blur-lg: 24px;
}

/* Dark Mode Variables */
[data-theme="dark"] {
    --bg-primary: #0f0f1e;
    --bg-secondary: #1a1a2e;
    --bg-glass: rgba(26, 26, 46, 0.7);
    --text-primary: #f7fafc;
    --text-secondary: #cbd5e0;
    --text-muted: #a0aec0;
    --border: rgba(255, 255, 255, 0.1);
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.5);
    --shadow-xl: 0 16px 64px rgba(0, 0, 0, 0.6);
}

/* ==================== BASE STYLES ==================== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

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

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-slow), color var(--transition-slow);
}

/* ==================== TYPOGRAPHY ==================== */
h1, h2, h3, h4, h5, h6 {
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: var(--spacing-md);
    color: var(--text-primary);
}

h1 { font-size: clamp(2.5rem, 5vw, 4rem); letter-spacing: -0.02em; }
h2 { font-size: clamp(2rem, 4vw, 3rem); letter-spacing: -0.01em; }
h3 { font-size: clamp(1.5rem, 3vw, 2rem); }
h4 { font-size: clamp(1.25rem, 2.5vw, 1.5rem); }
h5 { font-size: 1.125rem; }
h6 { font-size: 1rem; }

p {
    margin-bottom: var(--spacing-sm);
    color: var(--text-secondary);
    font-size: 1.0625rem;
}

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

a:hover {
    color: var(--accent-secondary);
}

code {
    font-family: var(--font-mono);
    background: var(--bg-glass);
    padding: 0.125rem 0.375rem;
    border-radius: var(--radius-sm);
    font-size: 0.875rem;
}

/* ==================== LAYOUT ==================== */
.container {
    max-width: 1280px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

.container-wide {
    max-width: 1440px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

.container-narrow {
    max-width: 960px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

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

/* ==================== NAVBAR ==================== */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: var(--bg-glass);
    backdrop-filter: blur(var(--blur-md));
    -webkit-backdrop-filter: blur(var(--blur-md));
    border-bottom: 1px solid var(--border);
    transition: all var(--transition-base);
}

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

.nav-container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--spacing-sm) var(--spacing-md);
    max-width: 1440px;
    margin: 0 auto;
}

.nav-brand {
    font-size: 1.25rem;
    font-weight: 700;
    background: var(--accent-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
}

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

.nav-link {
    color: var(--text-secondary);
    font-weight: 500;
    padding: var(--spacing-xs) var(--spacing-sm);
    border-radius: var(--radius-sm);
    transition: all var(--transition-fast);
    position: relative;
}

.nav-link:hover {
    color: var(--accent-primary);
    background: var(--bg-glass);
}

.nav-link.active::after {
    content: '';
    position: absolute;
    bottom: -2px;
    left: 0;
    right: 0;
    height: 2px;
    background: var(--accent-gradient);
    border-radius: var(--radius-full);
}

/* Mobile Menu Toggle */
.nav-toggle {
    display: none;
    background: none;
    border: none;
    cursor: pointer;
    padding: var(--spacing-xs);
    color: var(--text-primary);
    font-size: 1.5rem;
}

/* Theme Toggle */
.theme-toggle {
    background: var(--bg-glass);
    border: 1px solid var(--border);
    border-radius: var(--radius-full);
    padding: var(--spacing-xs);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    transition: all var(--transition-base);
}

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

/* ==================== HERO SECTION ==================== */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    padding-top: 80px;
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: radial-gradient(circle at 30% 50%, rgba(102, 126, 234, 0.1) 0%, transparent 50%),
                radial-gradient(circle at 70% 50%, rgba(118, 75, 162, 0.1) 0%, transparent 50%);
    pointer-events: none;
}

.hero-content {
    position: relative;
    z-index: 1;
}

.hero-badge {
    display: inline-block;
    background: var(--bg-glass);
    backdrop-filter: blur(var(--blur-sm));
    border: 1px solid var(--border);
    padding: var(--spacing-xs) var(--spacing-md);
    border-radius: var(--radius-full);
    font-size: 0.875rem;
    font-weight: 600;
    margin-bottom: var(--spacing-md);
    animation: fadeInDown 0.6s ease-out;
}

.hero h1 {
    margin-bottom: var(--spacing-md);
    animation: fadeInUp 0.6s ease-out 0.1s backwards;
}

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

.hero p {
    font-size: 1.25rem;
    max-width: 600px;
    margin: 0 auto var(--spacing-xl);
    animation: fadeInUp 0.6s ease-out 0.2s backwards;
}

.hero-buttons {
    display: flex;
    gap: var(--spacing-sm);
    justify-content: center;
    flex-wrap: wrap;
    animation: fadeInUp 0.6s ease-out 0.3s backwards;
}

/* ==================== BUTTONS ==================== */
.btn {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-xs);
    padding: 0.875rem 1.75rem;
    border-radius: var(--radius-md);
    font-weight: 600;
    font-size: 1rem;
    cursor: pointer;
    transition: all var(--transition-base);
    border: none;
    text-decoration: none;
    position: relative;
    overflow: hidden;
}

.btn::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.2), transparent);
    transition: left 0.5s;
}

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

.btn-primary {
    background: var(--accent-gradient);
    color: white;
    box-shadow: var(--shadow-md);
}

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

.btn-secondary {
    background: var(--bg-glass);
    backdrop-filter: blur(var(--blur-sm));
    color: var(--text-primary);
    border: 1px solid var(--border);
}

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

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

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

/* ==================== GLASS CARD ==================== */
.glass-card {
    background: var(--bg-glass);
    backdrop-filter: blur(var(--blur-md));
    -webkit-backdrop-filter: blur(var(--blur-md));
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    box-shadow: var(--shadow-sm);
    transition: all var(--transition-base);
}

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

.glass-card-header {
    margin-bottom: var(--spacing-md);
}

.glass-card-title {
    font-size: 1.5rem;
    margin-bottom: var(--spacing-xs);
}

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

.glass-card-body {
    color: var(--text-secondary);
}

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

/* ==================== STATS GRID ==================== */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--spacing-md);
    margin: var(--spacing-xl) 0;
}

.stat-card {
    background: var(--bg-glass);
    backdrop-filter: blur(var(--blur-md));
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    text-align: center;
    transition: all var(--transition-base);
    position: relative;
    overflow: hidden;
}

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

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

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

.stat-icon {
    font-size: 2.5rem;
    margin-bottom: var(--spacing-sm);
    background: var(--accent-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.stat-value {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: var(--spacing-xs);
    color: var(--text-primary);
}

.stat-label {
    color: var(--text-muted);
    font-size: 0.875rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

/* ==================== SECTION HEADER ==================== */
.section-header {
    text-align: center;
    margin-bottom: var(--spacing-xl);
}

.section-badge {
    display: inline-block;
    background: var(--accent-gradient);
    color: white;
    padding: var(--spacing-xs) var(--spacing-md);
    border-radius: var(--radius-full);
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    margin-bottom: var(--spacing-sm);
}

.section-title {
    font-size: clamp(2rem, 4vw, 3rem);
    margin-bottom: var(--spacing-sm);
}

.section-description {
    font-size: 1.125rem;
    color: var(--text-secondary);
    max-width: 600px;
    margin: 0 auto;
}

/* ==================== GRID LAYOUTS ==================== */
.grid-2 {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(400px, 1fr));
    gap: var(--spacing-lg);
}

.grid-3 {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--spacing-lg);
}

.grid-4 {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--spacing-md);
}

/* ==================== IMAGE STYLES ==================== */
.img-container {
    position: relative;
    overflow: hidden;
    border-radius: var(--radius-md);
    background: var(--bg-secondary);
}

.img-container img {
    width: 100%;
    height: auto;
    display: block;
    transition: transform var(--transition-slow);
}

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

/* ==================== TABLE STYLES ==================== */
.table-container {
    overflow-x: auto;
    border-radius: var(--radius-lg);
    background: var(--bg-glass);
    backdrop-filter: blur(var(--blur-md));
    border: 1px solid var(--border);
}

table {
    width: 100%;
    border-collapse: collapse;
}

thead {
    background: var(--accent-gradient);
    color: white;
}

th, td {
    padding: var(--spacing-sm) var(--spacing-md);
    text-align: left;
}

th {
    font-weight: 600;
    text-transform: uppercase;
    font-size: 0.875rem;
    letter-spacing: 0.05em;
}

tbody tr {
    border-bottom: 1px solid var(--border);
    transition: background var(--transition-fast);
}

tbody tr:hover {
    background: var(--bg-glass);
}

/* ==================== FOOTER ==================== */
.footer {
    background: var(--bg-secondary);
    border-top: 1px solid var(--border);
    padding: var(--spacing-xl) 0 var(--spacing-md);
    margin-top: var(--spacing-2xl);
}

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

.footer-section h4 {
    margin-bottom: var(--spacing-sm);
}

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

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

.footer-bottom {
    text-align: center;
    padding-top: var(--spacing-md);
    border-top: 1px solid var(--border);
    color: var(--text-muted);
    font-size: 0.875rem;
}

/* ==================== SCROLL TO TOP ==================== */
.scroll-top {
    position: fixed;
    bottom: var(--spacing-lg);
    right: var(--spacing-lg);
    width: 50px;
    height: 50px;
    background: var(--accent-gradient);
    color: white;
    border: none;
    border-radius: var(--radius-full);
    cursor: pointer;
    box-shadow: var(--shadow-lg);
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition-base);
    z-index: 999;
}

.scroll-top.visible {
    opacity: 1;
    visibility: visible;
}

.scroll-top:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-xl);
}

/* ==================== LOADING SCREEN ==================== */
.loading-screen {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    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;
}

.spinner {
    width: 60px;
    height: 60px;
    border: 4px solid var(--border);
    border-top-color: var(--accent-primary);
    border-radius: var(--radius-full);
    animation: spin 0.8s linear infinite;
}

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

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

@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

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

.slide-in-left {
    animation: slideInLeft 0.6s ease-out;
}

.slide-in-right {
    animation: slideInRight 0.6s ease-out;
}

@keyframes slideInLeft {
    from {
        opacity: 0;
        transform: translateX(-50px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

@keyframes slideInRight {
    from {
        opacity: 0;
        transform: translateX(50px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

/* Scroll Reveal */
.reveal {
    opacity: 0;
    transform: translateY(30px);
    transition: all 0.6s ease-out;
}

.reveal.active {
    opacity: 1;
    transform: translateY(0);
}

/* ==================== LIGHTBOX ==================== */
.lightbox {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.95);
    display: none;
    align-items: center;
    justify-content: center;
    z-index: 9999;
    padding: var(--spacing-lg);
}

.lightbox.active {
    display: flex;
}

.lightbox-content {
    position: relative;
    max-width: 90%;
    max-height: 90%;
}

.lightbox-content img {
    max-width: 100%;
    max-height: 90vh;
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-xl);
}

.lightbox-close,
.lightbox-prev,
.lightbox-next {
    position: absolute;
    background: var(--bg-glass);
    backdrop-filter: blur(var(--blur-md));
    border: 1px solid var(--border);
    color: white;
    font-size: 1.5rem;
    width: 50px;
    height: 50px;
    border-radius: var(--radius-full);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all var(--transition-base);
}

.lightbox-close { top: var(--spacing-lg); right: var(--spacing-lg); }
.lightbox-prev { left: var(--spacing-lg); top: 50%; transform: translateY(-50%); }
.lightbox-next { right: var(--spacing-lg); top: 50%; transform: translateY(-50%); }

.lightbox-close:hover,
.lightbox-prev:hover,
.lightbox-next:hover {
    background: var(--accent-gradient);
    transform: scale(1.1);
}

/* ==================== RESPONSIVE DESIGN ==================== */
@media (max-width: 768px) {
    .nav-menu {
        position: fixed;
        top: 70px;
        left: -100%;
        flex-direction: column;
        background: var(--bg-glass);
        backdrop-filter: blur(var(--blur-lg));
        width: 100%;
        padding: var(--spacing-lg);
        transition: left var(--transition-base);
        border-bottom: 1px solid var(--border);
    }
    
    .nav-menu.active {
        left: 0;
    }
    
    .nav-toggle {
        display: block;
    }
    
    .grid-2,
    .grid-3,
    .grid-4 {
        grid-template-columns: 1fr;
    }
    
    .hero {
        min-height: 80vh;
    }
    
    section {
        padding: var(--spacing-xl) 0;
    }
}

@media (max-width: 480px) {
    :root {
        font-size: 14px;
    }
    
    .hero-buttons {
        flex-direction: column;
    }
    
    .btn {
        width: 100%;
        justify-content: center;
    }
}

/* ==================== UTILITY CLASSES ==================== */
.text-center { text-align: center; }
.text-left { text-align: left; }
.text-right { text-align: right; }

.mt-xs { margin-top: var(--spacing-xs); }
.mt-sm { margin-top: var(--spacing-sm); }
.mt-md { margin-top: var(--spacing-md); }
.mt-lg { margin-top: var(--spacing-lg); }
.mt-xl { margin-top: var(--spacing-xl); }

.mb-xs { margin-bottom: var(--spacing-xs); }
.mb-sm { margin-bottom: var(--spacing-sm); }
.mb-md { margin-bottom: var(--spacing-md); }
.mb-lg { margin-bottom: var(--spacing-lg); }
.mb-xl { margin-bottom: var(--spacing-xl); }

.p-xs { padding: var(--spacing-xs); }
.p-sm { padding: var(--spacing-sm); }
.p-md { padding: var(--spacing-md); }
.p-lg { padding: var(--spacing-lg); }
.p-xl { padding: var(--spacing-xl); }

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

.success-text { color: var(--success); }
.warning-text { color: var(--warning); }
.error-text { color: var(--error); }