/* --- CSS Variables & Theming --- */
:root {
    --bg-color: #f8fafc;
    --surface-color: #ffffff;
    --text-main: #0f172a;
    --text-muted: #64748b;
    --primary: #3b82f6;
    --primary-hover: #2563eb;
    --accent: #10b981;
    --border: #e2e8f0;
    --shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --hover-shadow: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

[data-theme="dark"] {
    --bg-color: #000000;
    --surface-color: #000000;
    --text-main: #f8fafc;
    --text-muted: #94a3b8;
    --border: #334155;
    --shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.5);
    --hover-shadow: 0 20px 25px -5px rgba(0, 0, 0, 0.7);
}

/* --- Base Styles --- */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Segoe UI', system-ui, -apple-system, sans-serif;
}

body {
    background-color: var(--bg-color);
    color: var(--text-main);
    line-height: 1.6;
    transition: var(--transition);
}

.hidden { display: none !important; }

/* --- Navigation --- */
header {
    background-color: var(--surface-color);
    border-bottom: 1px solid var(--border);
    position: relative;
    z-index: 100;
}

.navbar {
    max-width: 1200px;
    margin: 0 auto;
    padding: 1rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 1.5rem;
    font-weight: bold;
    color: var(--primary);
}

.nav-links {
    display: flex;
    list-style: none;
    gap: 2rem;
}

.nav-links a {
    text-decoration: none;
    color: var(--text-main);
    font-weight: 500;
    transition: var(--transition);
}

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

#theme-toggle {
    background: none;
    border: none;
    font-size: 1.5rem;
    cursor: pointer;
    transition: var(--transition);
}

#theme-toggle:hover { transform: scale(1.1) rotate(15deg); }

/* --- Hero & Upload --- */
.hero {
    max-width: 800px;
    margin: 4rem auto;
    text-align: center;
    padding: 0 1rem;
}

.hero h1 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

.hero p {
    color: var(--text-muted);
    margin-bottom: 2rem;
}

.upload-container {
    border: 2px dashed var(--primary);
    border-radius: 1rem;
    padding: 4rem 2rem;
    background-color: var(--surface-color);
    transition: var(--transition);
}

.upload-container:hover {
    background-color: rgba(59, 130, 246, 0.05);
    border-color: var(--primary-hover);
    transform: translateY(-2px);
}

.upload-btn {
    background-color: var(--primary);
    color: white;
    padding: 0.75rem 2rem;
    border-radius: 0.5rem;
    cursor: pointer;
    font-weight: bold;
    display: inline-block;
    transition: var(--transition);
    box-shadow: var(--shadow);
}

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

.drag-text { margin-top: 1rem; font-size: 0.9rem; }

/* --- Editor Section --- */
.editor-container {
    background-color: var(--surface-color);
    border-radius: 1rem;
    padding: 2rem;
    box-shadow: var(--shadow);
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 2rem;
    text-align: left;
    margin-top: 2rem;
}

.preview-area img {
    max-width: 100%;
    border-radius: 0.5rem;
    border: 1px solid var(--border);
}

.controls-area {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.control-group {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.dimension-controls {
    display: flex;
    gap: 1rem;
}

input[type="number"], select {
    width: 100%;
    padding: 0.5rem;
    border: 1px solid var(--border);
    border-radius: 0.25rem;
    background-color: var(--bg-color);
    color: var(--text-main);
}

input[type="range"] {
    width: 100%;
    accent-color: var(--primary);
}

.primary-btn {
    background-color: var(--accent);
    color: white;
    border: none;
    padding: 1rem;
    border-radius: 0.5rem;
    font-size: 1rem;
    font-weight: bold;
    cursor: pointer;
    transition: var(--transition);
    box-shadow: var(--shadow);
}

.primary-btn:hover {
    background-color: #059669;
    transform: translateY(-2px);
    box-shadow: var(--hover-shadow);
}

/* --- Results Section --- */
.results-container {
    background-color: var(--surface-color);
    border-radius: 1rem;
    padding: 2rem;
    box-shadow: var(--shadow);
    margin-top: 2rem;
}

.comparison-grid {
    display: flex;
    justify-content: center;
    gap: 2rem;
    margin: 1.5rem 0;
}

.stat-box {
    background-color: var(--bg-color);
    padding: 1.5rem;
    border-radius: 0.5rem;
    border: 1px solid var(--border);
    min-width: 150px;
}

.stat-box h4 { margin-bottom: 0.5rem; color: var(--text-muted); }
.stat-box p { font-size: 1.2rem; font-weight: bold; }

.badge {
    background-color: var(--accent);
    color: white;
    font-size: 0.8rem !important;
    padding: 0.25rem 0.5rem;
    border-radius: 1rem;
    display: inline-block;
    margin-top: 0.5rem;
}

.download-btn {
    background-color: var(--primary);
    color: white;
    text-decoration: none;
    padding: 1rem 2rem;
    border-radius: 0.5rem;
    font-weight: bold;
    display: inline-block;
    margin-right: 1rem;
    transition: var(--transition);
}

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

.secondary-btn {
    background-color: transparent;
    border: 2px solid var(--border);
    color: var(--text-main);
    padding: 0.9rem 2rem;
    border-radius: 0.5rem;
    font-weight: bold;
    cursor: pointer;
    transition: var(--transition);
}

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

/* --- SEO Content Sections --- */
.content-section {
    max-width: 800px;
    margin: 4rem auto;
    padding: 0 1rem;
}

.content-section h2 { margin-bottom: 1rem; color: var(--primary); }
.faq-item { margin-bottom: 1.5rem; }
.faq-item h3 { margin-bottom: 0.5rem; }
.faq-item p { color: var(--text-muted); }


/* ========================================= */
/* --- Responsive Enhancements --- */
/* ========================================= */

@media (max-width: 768px) {
    /* Navbar fixed for mobile users instead of hiding */
    .navbar { 
        flex-direction: column; 
        gap: 1rem; 
        padding: 1rem; 
    }
    .nav-links { 
        display: flex; 
        flex-wrap: wrap; 
        justify-content: center; 
        gap: 1rem; 
        font-size: 0.9rem;
    }
    
    /* Grid & Layout Adjustments */
    .editor-container { grid-template-columns: 1fr; gap: 1.5rem; padding: 1.5rem; }
    .comparison-grid { flex-direction: column; gap: 1rem; }
    
    /* Spacing & Typography Scaling */
    .intro-title, .hero h1 { font-size: 2rem !important; }
    .hero, .content-section { margin: 2rem auto; }
    .upload-container { padding: 2.5rem 1rem; }
    .instructions-box { padding: 1.25rem !important; }
    
    /* Article Section Overrides */
    .articles-section { padding: 2rem 1rem; }
    
    /* Footer Links */
    .footer-links { flex-direction: column; align-items: center; gap: 1rem; }
}

@media (max-width: 480px) {
    /* Tight mobile sizing fixes */
    .dimension-controls { flex-direction: column; gap: 1rem; }
    
    .logo { font-size: 1.3rem; }
    
    /* Stack action buttons cleanly */
    .action-buttons {
        display: flex;
        flex-direction: column;
        gap: 1rem;
    }
    .download-btn { 
        margin-right: 0; 
        display: block; 
        text-align: center; 
        width: 100%;
    }
    .secondary-btn { 
        display: block; 
        width: 100%; 
    }
}