/* --- Variables & Theming --- */
:root[data-theme="light"] {
    --bg-color: #f5f7fa; --surface-color: #ffffff; --text-primary: #1e293b;
    --text-secondary: #64748b; --primary-color: #4f46e5; --primary-hover: #4338ca;
    --border-color: #e2e8f0; --shadow: 0 4px 6px -1px rgba(0,0,0,0.1), 0 2px 4px -1px rgba(0,0,0,0.06);
    --modal-overlay: rgba(0, 0, 0, 0.5);
}

:root[data-theme="dark"] {
    --bg-color: #0f172a; --surface-color: #1e293b; --text-primary: #f8fafc;
    --text-secondary: #94a3b8; --primary-color: #6366f1; --primary-hover: #818cf8;
    --border-color: #334155; --shadow: 0 4px 6px -1px rgba(0,0,0,0.5);
    --modal-overlay: rgba(0, 0, 0, 0.7);
}

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

body { background-color: var(--bg-color); color: var(--text-primary); display: flex; flex-direction: column; min-height: 100vh; transition: background-color 0.3s, color 0.3s; }
.hidden { display: none !important; }

/* --- Header --- */
header { background-color: var(--surface-color); padding: 1rem 2rem; display: flex; justify-content: space-between; align-items: center; box-shadow: var(--shadow); z-index: 100; }
.logo { font-size: 1.5rem; font-weight: bold; color: var(--primary-color); display: flex; align-items: center; gap: 0.5rem; }
.nav-links { display: flex; gap: 1.5rem; }
.nav-links a { color: var(--text-secondary); text-decoration: none; font-weight: 500; transition: color 0.2s; cursor: pointer; }
.nav-links a:hover, .nav-links a.active { color: var(--primary-color); }
.icon-btn { background: none; border: none; color: var(--text-primary); font-size: 1.2rem; cursor: pointer; padding: 0.5rem; }

/* --- Main Layout --- */
main { flex: 1; display: flex; padding: 2rem; gap: 2rem; max-width: 1400px; margin: 0 auto; width: 100%; }
.upload-container { flex: 1; border: 2px dashed var(--border-color); border-radius: 16px; display: flex; justify-content: center; align-items: center; text-align: center; background-color: var(--surface-color); transition: border-color 0.3s; padding: 3rem; margin: auto; max-width: 800px; width: 100%; }
.upload-container.dragover { border-color: var(--primary-color); background-color: rgba(99, 102, 241, 0.05); }
.upload-icon { font-size: 4rem; color: var(--primary-color); margin-bottom: 1rem; }
.upload-content p { color: var(--text-secondary); margin: 0.5rem 0 1.5rem 0; }
.primary-btn { background-color: var(--primary-color); color: white; border: none; padding: 0.75rem 1.5rem; border-radius: 8px; font-weight: 600; cursor: pointer; transition: background-color 0.2s; font-size: 1rem; }
.primary-btn:hover { background-color: var(--primary-hover); }

/* --- Workspace & Editor --- */
.workspace { display: flex; gap: 2rem; width: 100%; flex: 1; }
.editor-panel { flex: 2; background-color: var(--surface-color); border-radius: 12px; box-shadow: var(--shadow); padding: 1rem; display: flex; flex-direction: column; overflow: hidden; }

/* CRITICAL FIX FOR MOBILE: touch-action: none prevents scrolling while dragging */
.img-container { flex: 1; min-height: 400px; max-height: calc(100vh - 200px); touch-action: none; background-image: repeating-linear-gradient(45deg, var(--border-color) 25%, transparent 25%, transparent 75%, var(--border-color) 75%, var(--border-color)), repeating-linear-gradient(45deg, var(--border-color) 25%, var(--bg-color) 25%, var(--bg-color) 75%, var(--border-color) 75%, var(--border-color)); background-position: 0 0, 10px 10px; background-size: 20px 20px; }
img { display: block; max-width: 100%; }

/* Side Panel */
.side-panel { flex: 1; display: flex; flex-direction: column; gap: 1.5rem; min-width: 300px; }
.preview-card, .export-card { background-color: var(--surface-color); border-radius: 12px; padding: 1.5rem; box-shadow: var(--shadow); }
.preview-card h3, .export-card h3 { margin-bottom: 1rem; color: var(--text-primary); font-size: 1.1rem; }
.preview-container { width: 100%; height: 200px; overflow: hidden; border-radius: 8px; border: 1px solid var(--border-color); background-color: var(--bg-color); }
.control-group { margin-bottom: 1rem; display: flex; flex-direction: column; gap: 0.5rem; }
.control-group label { font-size: 0.9rem; color: var(--text-secondary); }
select { width: 100%; padding: 0.75rem; border-radius: 8px; border: 1px solid var(--border-color); background-color: var(--bg-color); color: var(--text-primary); font-size: 1rem; outline: none; }

/* --- Toolbar --- */
.controls-toolbar { background-color: var(--surface-color); padding: 1rem; border-radius: 12px; box-shadow: var(--shadow); display: flex; align-items: center; justify-content: center; gap: 1rem; margin-bottom: 1rem; }
.tool-btn { background: var(--bg-color); border: 1px solid var(--border-color); color: var(--text-primary); width: 40px; height: 40px; border-radius: 50%; display: flex; justify-content: center; align-items: center; cursor: pointer; transition: all 0.2s; }
.tool-btn:hover { background: var(--primary-color); color: white; border-color: var(--primary-color); }
.divider { width: 1px; height: 30px; background-color: var(--border-color); }

/* --- Footer --- */
footer { background-color: var(--surface-color); border-top: 1px solid var(--border-color); padding: 1.5rem 2rem; margin-top: auto; }
.footer-content { display: flex; justify-content: space-between; align-items: center; flex-wrap: wrap; gap: 1rem; color: var(--text-secondary); font-size: 0.9rem; }
.footer-links a { color: var(--text-secondary); text-decoration: none; margin-left: 1rem; transition: color 0.2s; cursor: pointer;}
.footer-links a:hover { color: var(--primary-color); }

/* --- Modals --- */
.modal-overlay { position: fixed; top: 0; left: 0; width: 100%; height: 100%; background: var(--modal-overlay); z-index: 1000; display: flex; justify-content: center; align-items: center; backdrop-filter: blur(3px); }
.modal-content { background: var(--surface-color); width: 90%; max-width: 600px; border-radius: 12px; box-shadow: var(--shadow); overflow: hidden; animation: slideUp 0.3s ease; }
.modal-header { padding: 1.5rem; border-bottom: 1px solid var(--border-color); display: flex; justify-content: space-between; align-items: center; }
.modal-header h2 { font-size: 1.25rem; color: var(--text-primary); }
.close-modal { background: none; border: none; color: var(--text-secondary); font-size: 1.5rem; cursor: pointer; transition: color 0.2s; }
.close-modal:hover { color: var(--primary-color); }
.modal-body { padding: 1.5rem; max-height: 70vh; overflow-y: auto; color: var(--text-secondary); line-height: 1.6; }
.modal-body p { margin-bottom: 1rem; }
.text-center { text-align: center; }

@keyframes slideUp { from { transform: translateY(20px); opacity: 0; } to { transform: translateY(0); opacity: 1; } }

/* --- Mobile Responsiveness --- */
@media (max-width: 900px) {
    main { flex-direction: column; padding: 1rem; padding-bottom: 90px; }
    .workspace { flex-direction: column; }
    .nav-links { display: none; }
    .controls-toolbar { position: fixed; bottom: 0; left: 0; width: 100%; margin: 0; border-radius: 0; border-top: 1px solid var(--border-color); z-index: 900; justify-content: space-around; padding: 0.75rem; }
    .tool-btn span { display: none; }
    .download-btn { padding: 0.5rem 1rem; font-size: 0.9rem; }
    .editor-panel { height: 60vh; }
    .img-container { min-height: unset; height: 100%; }
    footer { padding-bottom: 100px; }
}