.app-container{position:relative;width:100%;height:100vh}.loading-screen{display:flex;flex-direction:column;align-items:center;justify-content:center;height:100vh;background:linear-gradient(135deg,#4880db,#3b6bb3);color:#fff}.spinner-large{width:60px;height:60px;border:6px solid hsla(0,0%,100%,.3);border-top-color:#fff;border-radius:50%;animation:spin 1s linear infinite;margin-bottom:20px}@keyframes spin{0%{transform:rotate(0deg)}to{transform:rotate(1turn)}}.loading-screen p{font-size:18px;font-weight:500}.back-button{position:absolute;top:20px;left:20px;background:#fff;color:#4880db;border:none;padding:12px 24px;border-radius:8px;font-weight:600;cursor:pointer;z-index:1000;box-shadow:0 4px 12px rgba(0,0,0,.15);transition:all .2s ease}.back-button:hover{transform:translateY(-2px);box-shadow:0 6px 16px rgba(0,0,0,.2)}@media (max-width:768px){.back-button{top:10px;left:10px;padding:10px 20px;font-size:14px}}.modal-overlay{position:fixed;top:0;left:0;right:0;bottom:0;background:rgba(0,0,0,.08);backdrop-filter:blur(4px);display:flex;align-items:center;justify-content:center;z-index:1000;padding:20px;animation:fadeIn .2s ease-out}.modal{background:#fff;border-radius:16px;max-width:480px;width:100%;box-shadow:0 32px 64px rgba(0,0,0,.3);animation:slideUp .3s ease-out;overflow:hidden}@keyframes fadeIn{0%{opacity:0}to{opacity:1}}@keyframes slideUp{0%{opacity:0;transform:translateY(20px) scale(.95)}to{opacity:1;transform:translateY(0) scale(1)}}.modal-header{display:flex;justify-content:space-between;align-items:center;padding:24px 24px 0}.modal-header h2{margin:0;font-size:20px;font-weight:600;color:#111827}.close-btn{background:none;border:none;color:#6b7280;cursor:pointer;padding:8px;border-radius:8px;transition:all .2s ease;display:flex;align-items:center;justify-content:center}.close-btn:hover{background:#f3f4f6;color:#374151}.modal-body{padding:24px}.modal-text{color:#6b7280;font-size:14px;margin:0 0 24px;text-align:center}.upload-area{border:2px dashed #d1d5db;border-radius:12px;padding:48px 24px;text-align:center;cursor:pointer;transition:all .2s ease;background:#fafafa}.upload-area:hover{border-color:#4880db;background:#f8faff}.upload-area.drag-over{background:#f0f4ff;border:3px solid #4880db}.upload-icon{color:#9ca3af;margin-bottom:16px;transition:color .2s ease}.upload-area:hover .upload-icon{color:#4880db}.upload-area h3{margin:0 0 8px;font-size:16px;font-weight:500;color:#374151}.upload-area p{margin:0;font-size:14px;color:#6b7280}@media (max-width:768px){.modal{margin:20px;max-width:none}.modal-header{padding:20px 20px 0}.modal-body{padding:20px}.upload-area{padding:40px 20px}}