.loading-spinner {
            border: 3px solid #f3f3f3;
            border-top: 3px solid #3b82f6;
            border-radius: 50%;
            width: 40px;
            height: 40px;
            animation: spin 1s linear infinite;
        }
        @keyframes spin {
            0% { transform: rotate(0deg); }
            100% { transform: rotate(360deg); }
        }
        
        /* 悬浮预览窗口样式 */
        #floatingPreview {
            position: fixed;
            z-index: 9999;
            background: white;
            border-radius: 12px;
            box-shadow: 0 10px 40px rgba(0,0,0,0.3);
            display: none;
            touch-action: none;
            user-select: none;
        }
        
        #floatingPreview.active {
            display: block;
        }
        
        #floatingPreview .preview-header {
            cursor: move;
            padding: 12px;
            background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
            border-radius: 12px 12px 0 0;
            color: white;
            display: flex;
            justify-content: space-between;
            align-items: center;
        }
        
        #floatingPreview .preview-content {
            padding: 8px;
            max-height: 70vh;
            overflow: auto;
        }
        
        #floatingPreview canvas {
            max-width: 100%;
            height: auto;
            border-radius: 4px;
        }
        
        @media (max-width: 768px) {
            #floatingPreview {
                width: 90vw !important;
                max-width: 350px;
            }
        }
        
        @media (min-width: 769px) {
            #floatingPreview {
                width: 400px;
            }
        }
        
        .resize-handle {
            position: absolute;
            bottom: 0;
            right: 0;
            width: 20px;
            height: 20px;
            cursor: nwse-resize;
            background: linear-gradient(135deg, transparent 50%, rgba(0,0,0,0.2) 50%);
            border-radius: 0 0 12px 0;
        }