/* Base Styles & Variables */
:root {
    /* Light Theme */
    --primary-color: #2563eb;
    --primary-light: #3b82f6;
    --primary-dark: #1d4ed8;
    --text-color: #1f2937;
    --text-secondary: #4b5563;
    --bg-color: #ffffff;
    --bg-secondary: #f9fafb;
    --border-color: #e5e7eb;
    --success-color: #10b981;
    --error-color: #ef4444;
    --warning-color: #f59e0b;
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --radius-sm: 0.25rem;
    --radius: 0.5rem;
    --radius-lg: 1rem;
    --radius-xl: 1.5rem;
    --transition: all 0.2s ease-in-out;
}

/* Dark Theme */
[data-theme="dark"] {
    --primary-color: #3b82f6;
    --primary-light: #60a5fa;
    --primary-dark: #2563eb;
    --text-color: #f9fafb;
    --text-secondary: #d1d5db;
    --bg-color: #111827;
    --bg-secondary: #1f2937;
    --border-color: #374151;
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.2);
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.2), 0 2px 4px -1px rgba(0, 0, 0, 0.12);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.2), 0 4px 6px -2px rgba(0, 0, 0, 0.15);
}

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

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

body {
    font-family: 'Segoe UI', system-ui, -apple-system, sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--bg-color);
    transition: background-color 0.3s ease, color 0.3s ease;
    overflow-x: hidden;
}

h1, h2, h3, h4, h5, h6 {
    line-height: 1.2;
    margin-bottom: 1rem;
    font-weight: 700;
    color: var(--text-color);
}

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

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

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

button, input, select, textarea {
    font-family: inherit;
    font-size: 1rem;
}

button {
    cursor: pointer;
    border: none;
    background: none;
}

.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1.5rem;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.75rem 1.5rem;
    border-radius: var(--radius);
    font-weight: 600;
    text-align: center;
    transition: var(--transition);
    white-space: nowrap;
    gap: 0.5rem;
}

.btn i {
    font-size: 1.1em;
}

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

.btn-primary:hover {
    background-color: var(--primary-dark);
    transform: translateY(-1px);
    box-shadow: var(--shadow-lg);
}

.btn-primary:active {
    transform: translateY(0);
}

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

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

.btn-share {
    width: 3rem;
    height: 3rem;
    border-radius: 50%;
    background-color: var(--bg-secondary);
    color: var(--text-color);
    display: flex;
    align-items: center;
    justify-content: center;
    transition: var(--transition);
}

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

/* Header */
.header {
    padding: 1.5rem 0;
    background-color: var(--bg-color);
    box-shadow: var(--shadow-sm);
    position: sticky;
    top: 0;
    z-index: 1000;
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
}

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

.logo h1 {
    font-size: 1.75rem;
    font-weight: 800;
    background: linear-gradient(90deg, var(--primary-color), var(--primary-light));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    margin: 0;
}

/* Hero Section */
.hero {
    padding: 4rem 0;
    text-align: center;
    background: linear-gradient(135deg, rgba(37, 99, 235, 0.05) 0%, rgba(59, 130, 246, 0.05) 100%);
}

.hero h1 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
    background: linear-gradient(90deg, var(--primary-color), var(--primary-light));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    display: inline-block;
}

.subtitle {
    font-size: 1.25rem;
    color: var(--text-secondary);
    max-width: 700px;
    margin: 0 auto 3rem;
}

/* Upload Area */
.upload-container {
    background-color: var(--bg-color);
    border-radius: var(--radius-lg);
    padding: 2rem;
    box-shadow: var(--shadow);
    margin: 0 auto;
    max-width: 800px;
}

.drop-zone {
    border: 2px dashed var(--border-color);
    border-radius: var(--radius);
    padding: 3rem 2rem;
    text-align: center;
    cursor: pointer;
    transition: var(--transition);
    margin-bottom: 2rem;
    position: relative;
    overflow: hidden;
}

.drop-zone:hover, .drop-zone.drag-over {
    border-color: var(--primary-color);
    background-color: rgba(59, 130, 246, 0.05);
}

.drop-zone i {
    font-size: 3rem;
    color: var(--primary-color);
    margin-bottom: 1rem;
    opacity: 0.8;
}

.drop-zone h3 {
    margin-bottom: 0.5rem;
    color: var(--text-color);
}

.drop-zone p {
    color: var(--text-secondary);
    margin-bottom: 0;
}

#file-input {
    display: none;
}

/* Image Previews */
.image-previews {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(120px, 1fr));
    gap: 1rem;
    margin-bottom: 2rem;
}

.image-preview {
    position: relative;
    border-radius: var(--radius);
    overflow: hidden;
    background-color: var(--bg-secondary);
    aspect-ratio: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
}

.image-preview img {
    max-width: 100%;
    max-height: 100%;
    object-fit: contain;
}

.image-actions {
    position: absolute;
    top: 0.5rem;
    right: 0.5rem;
    display: flex;
    gap: 0.5rem;
}

.image-action-btn {
    width: 28px;
    height: 28px;
    border-radius: 50%;
    background-color: rgba(0, 0, 0, 0.6);
    color: white;
    display: flex;
    align-items: center;
    justify-content: center;
    border: none;
    cursor: pointer;
    transition: var(--transition);
}

.image-action-btn:hover {
    background-color: var(--primary-color);
    transform: scale(1.1);
}

/* Settings Panel */
.settings-panel {
    background-color: var(--bg-secondary);
    border-radius: var(--radius);
    padding: 1.5rem;
    margin-bottom: 2rem;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1.5rem;
}

.setting {
    display: flex;
    flex-direction: column;
}

.setting label {
    font-weight: 600;
    margin-bottom: 0.5rem;
    color: var(--text-color);
}

.setting select {
    padding: 0.5rem;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    background-color: var(--bg-color);
    color: var(--text-color);
    cursor: pointer;
}

/* Action Buttons */
.action-buttons {
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
}

/* Output Section */
.output-section {
    padding: 4rem 0;
    background-color: var(--bg-secondary);
}

.output-section h2 {
    text-align: center;
    margin-bottom: 2rem;
}

.preview-container {
    background-color: var(--bg-color);
    border-radius: var(--radius);
    padding: 2rem;
    box-shadow: var(--shadow);
    max-width: 800px;
    margin: 0 auto;
}

.pdf-preview {
    width: 100%;
    min-height: 500px;
    border: 1px solid var(--border-color);
    border-radius: var(--radius);
    margin-bottom: 2rem;
    overflow: hidden;
}

.download-options {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 1.5rem;
    flex-wrap: wrap;
}

.share-buttons {
    display: flex;
    gap: 1rem;
}

/* FAQ Section */
.faq-section {
    padding: 4rem 0;
}

.faq-container {
    max-width: 800px;
    margin: 0 auto;
}

.faq-item {
    margin-bottom: 1rem;
    border: 1px solid var(--border-color);
    border-radius: var(--radius);
    overflow: hidden;
}

.faq-question {
    width: 100%;
    padding: 1.25rem 1.5rem;
    text-align: left;
    background-color: var(--bg-secondary);
    border: none;
    font-weight: 600;
    display: flex;
    justify-content: space-between;
    align-items: center;
    cursor: pointer;
    transition: var(--transition);
}

.faq-question:hover {
    background-color: var(--border-color);
}

.faq-answer {
    padding: 1.5rem;
    background-color: var(--bg-color);
    border-top: 1px solid var(--border-color);
    display: none;
}

.faq-item.active .faq-answer {
    display: block;
}

.faq-question i {
    transition: transform 0.3s ease;
}

.faq-item.active .faq-question i {
    transform: rotate(180deg);
}

/* Footer */
.footer {
    background-color: var(--bg-secondary);
    padding: 4rem 0 2rem;
    color: var(--text-secondary);
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-bottom: 3rem;
}

.footer-section h3 {
    color: var(--text-color);
    margin-bottom: 1.5rem;
    font-size: 1.5rem;
}

.footer-section h4 {
    color: var(--text-color);
    margin-bottom: 1.25rem;
    font-size: 1.1rem;
}

.footer-section ul {
    list-style: none;
}

.footer-section ul li {
    margin-bottom: 0.75rem;
}

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

.footer-section a:hover {
    color: var(--primary-color);
    padding-left: 0.25rem;
}

.social-links {
    display: flex;
    gap: 1rem;
}

.social-links a {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 36px;
    height: 36px;
    background-color: var(--bg-color);
    border-radius: 50%;
    color: var(--text-color);
    transition: var(--transition);
}

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

.footer-bottom {
    text-align: center;
    padding-top: 2rem;
    border-top: 1px solid var(--border-color);
}

/* Utility Classes */
.hidden {
    display: none !important;
}

/* Animations */
@keyframes fadeIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

.fade-in {
    animation: fadeIn 0.3s ease forwards;
}

/* Responsive Styles */
@media (max-width: 768px) {
    .hero h1 {
        font-size: 2rem;
    }
    
    .subtitle {
        font-size: 1.1rem;
    }
    
    .settings-panel {
        grid-template-columns: 1fr;
    }
    
    .action-buttons {
        flex-direction: column;
    }
    
    .action-buttons .btn {
        width: 100%;
    }
    
    .download-options {
        flex-direction: column;
    }
}

/* Print Styles */
@media print {
    .header, .footer, .settings-panel, .action-buttons, .share-buttons {
        display: none !important;
    }
    
    body {
        padding: 0;
        background: white;
        color: black;
    }
    
    .container {
        padding: 0;
        max-width: 100%;
    }
    
    .pdf-preview {
        border: none;
        min-height: auto;
    }
}