/* FreePDF - Custom Styles */

/* CSS Variables for consistent theming */
:root {
    --primary-color: #007bff;
    --secondary-color: #6c757d;
    --success-color: #28a745;
    --danger-color: #dc3545;
    --warning-color: #ffc107;
    --info-color: #17a2b8;
    --light-color: #f8f9fa;
    --dark-color: #343a40;
    --border-radius: 0.5rem;
    --box-shadow: 0 0.125rem 0.25rem rgba(0, 0, 0, 0.075);
    --transition: all 0.15s ease-in-out;
}

/* Performance optimizations */
* {
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    color: var(--dark-color);
    background-color: #ffffff;
}

/* Optimize font loading */
@font-face {
    font-family: 'Segoe UI';
    font-display: swap;
}

/* Hero section gradient */
.bg-gradient-primary {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    position: relative;
    overflow: hidden;
}

.bg-gradient-primary::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 1000 100" fill="white" opacity="0.1"><polygon points="1000,100 1000,0 0,100"/></svg>') no-repeat center bottom;
    background-size: cover;
}

/* Upload area styles */
.upload-area {
    border: 2px dashed #dee2e6;
    border-radius: var(--border-radius);
    transition: var(--transition);
    background-color: #f8f9fa;
}

.upload-area:hover {
    border-color: var(--primary-color);
    background-color: rgba(0, 123, 255, 0.05);
}

.upload-area.dragover {
    border-color: var(--success-color);
    background-color: rgba(40, 167, 69, 0.05);
    transform: scale(1.02);
}

/* Card enhancements */
.card {
    border: none;
    border-radius: var(--border-radius);
    transition: var(--transition);
}

.card:hover {
    transform: translateY(-2px);
    box-shadow: 0 0.5rem 1rem rgba(0, 0, 0, 0.15);
}

/* Button enhancements */
.btn {
    border-radius: var(--border-radius);
    font-weight: 500;
    transition: var(--transition);
    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%;
}

.conversion-btn {
    min-height: 60px;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
}

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

/* Progress bar animation */
.progress {
    height: 8px;
    border-radius: 4px;
    overflow: hidden;
}

.progress-bar {
    background: linear-gradient(45deg, var(--primary-color), var(--info-color));
    transition: width 0.3s ease;
}

/* Ad placeholder styles */
.ad-banner-top {
    background-color: var(--light-color);
    padding: 10px 0;
    text-align: center;
    border-bottom: 1px solid #dee2e6;
}

.ad-placeholder {
    background-color: #e9ecef;
    color: var(--secondary-color);
    padding: 20px;
    border: 1px dashed #ced4da;
    border-radius: var(--border-radius);
    font-size: 14px;
    font-weight: 500;
}

.ad-sidebar .ad-placeholder {
    height: 250px;
    display: flex;
    align-items: center;
    justify-content: center;
}

/* Navigation enhancements */
.navbar-brand {
    font-size: 1.5rem;
    font-weight: 700;
}

.navbar-nav .nav-link {
    font-weight: 500;
    transition: var(--transition);
    position: relative;
}

.navbar-nav .nav-link:hover {
    color: var(--primary-color) !important;
}

.navbar-nav .nav-link.active::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 50%;
    transform: translateX(-50%);
    width: 20px;
    height: 2px;
    background-color: var(--primary-color);
    border-radius: 1px;
}

/* Feature cards */
.feature-card {
    transition: var(--transition);
    border: 1px solid rgba(0, 0, 0, 0.05);
}

.feature-card:hover {
    border-color: var(--primary-color);
    box-shadow: 0 0.5rem 1rem rgba(0, 123, 255, 0.15);
}

/* FAQ section */
.accordion-button {
    font-weight: 500;
    background-color: transparent;
    border: none;
    box-shadow: none;
}

.accordion-button:not(.collapsed) {
    background-color: rgba(0, 123, 255, 0.05);
    color: var(--primary-color);
}

.accordion-button:focus {
    box-shadow: 0 0 0 0.25rem rgba(0, 123, 255, 0.25);
}

/* Footer */
footer {
    background: linear-gradient(135deg, #2c3e50 0%, #34495e 100%);
}

footer a {
    transition: var(--transition);
    text-decoration: none;
}

footer a:hover {
    color: var(--primary-color) !important;
}

.social-links a {
    display: inline-block;
    width: 40px;
    height: 40px;
    line-height: 40px;
    text-align: center;
    border-radius: 50%;
    background-color: rgba(255, 255, 255, 0.1);
    transition: var(--transition);
}

.social-links a:hover {
    background-color: var(--primary-color);
    transform: translateY(-2px);
}

/* Responsive design */
@media (max-width: 768px) {
    .display-4 {
        font-size: 2rem;
    }
    
    .hero-section {
        text-align: center;
    }
    
    .conversion-btn {
        min-height: 50px;
        font-size: 0.9rem;
    }
    
    .upload-content {
        padding: 2rem 1rem !important;
    }
    
    .ad-banner-top {
        display: none; /* Hide top banner on mobile */
    }
}

@media (max-width: 576px) {
    .container {
        padding-left: 15px;
        padding-right: 15px;
    }
    
    .card-body {
        padding: 1rem;
    }
    
    .btn-lg {
        padding: 0.5rem 1rem;
        font-size: 1rem;
    }
}

/* Loading states */
.loading {
    opacity: 0.6;
    pointer-events: none;
}

.loading::after {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 20px;
    height: 20px;
    border: 2px solid #f3f3f3;
    border-top: 2px solid var(--primary-color);
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

@keyframes spin {
    0% { transform: translate(-50%, -50%) rotate(0deg); }
    100% { transform: translate(-50%, -50%) rotate(360deg); }
}

/* Accessibility improvements */
.visually-hidden {
    position: absolute !important;
    width: 1px !important;
    height: 1px !important;
    padding: 0 !important;
    margin: -1px !important;
    overflow: hidden !important;
    clip: rect(0, 0, 0, 0) !important;
    white-space: nowrap !important;
    border: 0 !important;
}

/* Focus styles for accessibility */
.btn:focus,
.nav-link:focus,
.accordion-button:focus {
    outline: 2px solid var(--primary-color);
    outline-offset: 2px;
}

/* High contrast mode support */
@media (prefers-contrast: high) {
    .upload-area {
        border-width: 3px;
    }
    
    .btn {
        border-width: 2px;
    }
}

/* Reduced motion support */
@media (prefers-reduced-motion: reduce) {
    * {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
        scroll-behavior: auto !important;
    }
}

/* Print styles */
@media print {
    .ad-banner-top,
    .ad-sidebar,
    .navbar,
    footer {
        display: none !important;
    }
    
    .hero-section {
        background: none !important;
        color: black !important;
    }
    
    .card {
        border: 1px solid #000 !important;
        box-shadow: none !important;
    }
}

/* Dark mode support */
@media (prefers-color-scheme: dark) {
    :root {
        --dark-color: #ffffff;
        --light-color: #1a1a1a;
    }
    
    body {
        background-color: #1a1a1a;
        color: #ffffff;
    }
    
    .card {
        background-color: #2d2d2d;
        border-color: #404040;
    }
    
    .upload-area {
        background-color: #2d2d2d;
        border-color: #404040;
    }
    
    .navbar {
        background-color: #2d2d2d !important;
    }
    
    .bg-light {
        background-color: #2d2d2d !important;
    }
}

/* Performance optimizations */
.card-img-top,
.upload-content i {
    will-change: transform;
}

/* Smooth scrolling for better UX */
html {
    scroll-padding-top: 80px;
}

/* Optimize images */
img {
    max-width: 100%;
    height: auto;
    loading: lazy;
}

/* Critical CSS for above-the-fold content */
.hero-section,
.navbar,
.upload-area {
    contain: layout style paint;
}