.operate_area {
            display: flex;
            gap: 30px;
            padding: 30px;
            position: relative;
        }
        
        @media (max-width: 900px) {
            .operate_area {
                flex-direction: column;
            }
            .preview-section {
                width: 100%;
            }
        }
        
        .operate_area_left {
            flex: 1;
            min-width: 0;
            position: relative;
        }
        
        .preview-section {
            width: 400px;
            flex-shrink: 0;
        }
        
        .upload-area {
            height: 420px;
            border: 2px dashed #3498db;
            border-radius: 12px;
            background: #f8f9fc;
            display: flex;
            flex-direction: column;
            align-items: center;
            justify-content: center;
            cursor: pointer;
            transition: all 0.3s ease;
            margin-bottom: 20px;
            position: relative;
            overflow: hidden;
        }
        
        .upload-area:hover {
            border-color: #2980b9;
            background: #e8f4fe;
        }
        
        .upload-area i {
            font-size: 5rem;
            color: #3498db;
            margin-bottom: 20px;
            transition: transform 0.3s ease;
        }
        
        .upload-area:hover i {
            transform: translateY(-5px);
        }
        
        .upload-label {
            font-size: 1.4rem;
            font-weight: 600;
            color: #3498db;
            text-align: center;
        }
        
        .hint {
            font-size: 0.95rem;
            color: #7f8c8d;
            margin-top: 12px;
            max-width: 85%;
            text-align: center;
        }
        
        .image-container {
            height: 420px;
            overflow: hidden;
            border-radius: 12px;
            background-color: #f0f0f0;
            background-image: 
                linear-gradient(45deg, #e0e0e0 25%, transparent 25%), 
                linear-gradient(-45deg, #e0e0e0 25%, transparent 25%),
                linear-gradient(45deg, transparent 75%, #e0e0e0 75%),
                linear-gradient(-45deg, transparent 75%, #e0e0e0 75%);
            background-size: 20px 20px;
            background-position: 0 0, 0 10px, 10px -10px, -10px 0px;
            position: relative;
            box-shadow: inset 0 0 20px rgba(0,0,0,0.05);
            border: 1px solid #e0e0e0;
            display: flex;
            align-items: center;
            justify-content: center;
        }
        
        #image-display {
            max-width: 100%;
            max-height: 100%;
            display: block;
            position: relative;
            z-index: 1;
        }
        
        .size-display {
            position: absolute;
            top: 15px;
            left: 15px;
            background: rgba(52, 152, 219, 0.9);
            color: white;
            padding: 8px 16px;
            border-radius: 20px;
            font-size: 14px;
            z-index: 100;
            font-weight: 600;
            box-shadow: 0 4px 12px rgba(0,0,0,0.15);
        }
        
        .preview-title {
            display: flex;
            justify-content: space-between;
            align-items: center;
            margin-bottom: 18px;
        }
        
        h2 {
            font-size: 1.5rem;
            color: #2c3e50;
            font-weight: 700;
            position: relative;
            padding-bottom: 8px;
        }
        
        h2::after {
            content: '';
            position: absolute;
            bottom: 0;
            left: 0;
            width: 60px;
            height: 3px;
            background: #3498db;
            border-radius: 3px;
        }
        
        .preview-container {
            height:420px;
            display: flex;
            align-items: center;
            justify-content: center;
            background: white;
            border: 1px solid #e0e0e0;
            border-radius: 12px;
            overflow: hidden;
            box-shadow: 0 8px 18px rgba(0,0,0,0.05);
            background-image: 
                linear-gradient(45deg, #f0f0f0 25%, transparent 25%), 
                linear-gradient(-45deg, #f0f0f0 25%, transparent 25%),
                linear-gradient(45deg, transparent 75%, #f0f0f0 75%),
                linear-gradient(-45deg, transparent 75%, #f0f0f0 75%);
            background-size: 20px 20px;
            background-position: 0 0, 0 10px, 10px -10px, -10px 0px;
            position: relative;
        }
        
        #preview-image {
            max-width: 100%;
            max-height: 100%;
            object-fit: contain;
        }
        
        .crop-overlay {
            position: absolute;
            border: 3px solid #3498db;
            box-shadow: 0 0 0 9999px rgba(0, 0, 0, 0.4);
            cursor: move;
            z-index: 10;
        }
        
        .crop-overlay .handle {
            position: absolute;
            width: 12px;
            height: 12px;
            background: #3498db;
            border: 2px solid white;
            border-radius: 50%;
            z-index: 11;
        }
        
        .crop-overlay .handle-tl { top: -6px; left: -6px; cursor: nwse-resize; }
        .crop-overlay .handle-tr { top: -6px; right: -6px; cursor: nesw-resize; }
        .crop-overlay .handle-bl { bottom: -6px; left: -6px; cursor: nesw-resize; }
        .crop-overlay .handle-br { bottom: -6px; right: -6px; cursor: nwse-resize; }
        .crop-overlay .handle-t { top: -6px; left: 50%; transform: translateX(-50%); cursor: ns-resize; }
        .crop-overlay .handle-r { right: -6px; top: 50%; transform: translateY(-50%); cursor: ew-resize; }
        .crop-overlay .handle-b { bottom: -6px; left: 50%; transform: translateX(-50%); cursor: ns-resize; }
        .crop-overlay .handle-l { left: -6px; top: 50%; transform: translateY(-50%); cursor: ew-resize; }
        
        .controls {
            background: linear-gradient(135deg, #f8f9fc 0%, #eef2f6 100%);
            border-radius: 12px;
            padding: 20px;
            border: 1px solid #e1e8f0;
            box-shadow: 0 6px 16px rgba(0,0,0,0.03);
        }
        
        .size-control {
            margin-bottom: 20px;
        }
        
        .size-label {
            display: block;
            margin-bottom: 12px;
            font-weight: 600;
            color: #2c3e50;
            font-size: 1.12rem;
            position: relative;
            padding-left: 12px;
        }
        
        .size-label::before {
            content: "";
            position: absolute;
            left: 0;
            top: 50%;
            transform: translateY(-50%);
            width: 6px;
            height: 6px;
            background: #3498db;
            border-radius: 50%;
        }
        
        .size-inputs {
            display: flex;
            gap: 15px;
            margin-bottom: 15px;
            align-items: center;
        }
        
        .input-group {
            flex: 1;
            position: relative;
        }
        
        .input-group label {
            display: block;
            margin-bottom: 6px;
            color: #5a6778;
            font-weight: 500;
            font-size: 13px;
        }
        
        .size-input {
            width: 100%;
            padding: 12px;
            border: 2px solid #dce4ec;
            border-radius: 10px;
            font-size: 15px;
            text-align: center;
            transition: all 0.3s ease;
            font-weight: 600;
            color: #2c3e50;
            box-shadow: 0 2px 8px rgba(0,0,0,0.05);
        }
        
        .size-input:focus {
            border-color: #3498db;
            outline: none;
            box-shadow: 0 0 0 3px rgba(52, 152, 219, 极细的边框线0.2);
        }
        
        .divider {
            color: #7f8c8d;
            font-size: 20px;
            font-weight: 400;
            margin-top: 25px;
        }
        
        .aspect-lock {
            display: flex;
            align-items: center;
            margin-bottom: 20px;
        }
        
        .aspect-lock label {
            margin-left: 10px;
            font-weight: 500;
            color: #5a6778;
            cursor: pointer;
            font-size: 14px;
        }
        
        .format-select {
            width: 100%;
            padding: 12px;
            border: 2px solid #dce4ec;
            border-radius: 10px;
            font-size: 15px;
            background: white;
            transition: all 0.3s ease;
            font-weight: 500;
            color: #2c3e50;
            box-shadow: 0 2px 8px rgba(0,0,0,0.05);
        }
        
        .format-select:focus {
            border-color: #3498db;
            outline: none;
            box-shadow: 0 0 0 3px rgba(52, 152, 219, 0.2);
        }
        
        .action-buttons {
            display: flex;
            gap: 15px;
        }
        
        .action-btn {
            flex: 1;
            display: flex;
            align-items: center;
            justify-content: center;
            padding: 14px;
            border: none;
            border-radius: 10px;
            font-weight: 600;
            font-size: 16px;
            cursor: pointer;
            transition: all 0.3s ease;
            gap: 10px;
            box-shadow: 0 4px 10px rgba(0,0,0,0.1);
        }
        
        .action-btn:hover {
            transform: translateY(-3px);
            box-shadow: 0 6px 14px rgba(0,0,0,0.15);
        }
        
        .preview-btn {
            background: #2c3e50;
            color: white;
        }
        
        .preview-btn:hover {
            background: #1a252f;
        }
        
        .download-btn {
            background: linear-gradient(135deg, #3498db 0%, #1a5d8f 100%);
            color: white;
        }
        
        .download-btn:hover {
            background: linear-gradient(135deg, #2980b9 0%, #154f76 100%);
        }
        
        .action-btn i {
            font-size: 1.2rem;
        }
        
        .info {
            padding: 20px;
            background: #f8f9fc;
            border-radius: 12px;
            margin: 0 0 20px;
            border-left: 5px solid #3498db;
            position: relative;
            margin-top:30px;
        }
        .info h3 {
            font-size: 1.3rem;
            color: #2c3e50;
            margin-bottom: 12px;
            font-weight: 700;
        }
        
        .info p {
            color: #5a6778;
            line-height: 1.7;
            font-size: 14px;
        }
        
        .toolbar {
            display: flex;
            gap: 15px;
            margin-top: 15px;
            justify-content: center;
            padding: 0 20px;
        }
        
        .tool-btn {
            padding: 12px 24px;
            background: #3498db;
            color: white;
            border: none;
            border-radius: 8px;
            cursor: pointer;
            font-weight: 600;
            font-size: 1rem;
            display: flex;
            align-items: center;
            gap: 8px;
            transition: all 0.3s ease;
            box-shadow: 0 4px 12px rgba(52, 152, 219, 0.3);
        }
        
        .tool-btn:hover {
            background: #2980b9;
            transform: translateY(-2px);
            box-shadow: 0 6px 16px rgba(52, 152, 219, 0.4);
        }
        
        .tool-btn i {
            font-size: 1.1rem;
        }
        
        #full-preview {
            position: fixed;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            background: rgba(0, 0, 0, 0.9);
            z-index: 10000;
            display: none;
            align-items: center;
            justify-content: center;
            overflow: auto;
            padding: 20px;
        }
        
        #full-preview-content {
            max-width: 100%;
            max-height: 100%;
            margin: auto;
            display: flex;
            flex-direction: column;
        }
        
        #full-preview-image {
            max-width: 100%;
            max-height: 80vh;
            object-fit: contain;
            border-radius: 8px;
            box-shadow: 0 0 40px rgba(0,0,0,0.5);
            margin-bottom: 20px;
        }
        
        .full-preview-dimension {
            color: white;
            font-size: 1.1rem;
            font-weight: 500;
            text-align: center;
            background: rgba(52, 152, 219, 0.8);
            padding: 10px 18px;
            border-radius: 30px;
            margin-top: 10px;
        }
        
        .close-preview-btn {
            position: absolute;
            top: 30px;
            right: 30px;
            padding: 12px 24px;
            background: #e74c3c;
            color: white;
            border: none;
            border-radius: 8px;
            cursor: pointer;
            font-weight: 600;
            font-size: 1rem;
            display: flex;
            align-items: center;
            gap: 8px;
            transition: all 0.3s ease;
            box-shadow: 0 4px 12px rgba(231, 76, 60, 0.3);
        }
        
        .close-preview-btn:hover {
            background: #c0392b;
            transform: translateY(-2px);
            box-shadow: 0 6px 16px rgba(231, 76, 60, 0.4);
        }
        
        .close-preview-btn i {
            font-size: 1.1rem;
        }
        
        .ratio-message {
            position: absolute;
            top: 30px;
            right: 30px;
            background: #2ecc71;
            color: white;
            padding: 8px 15px;
            border-radius: 20px;
            font-size: 13px;
            font-weight: 500;
            z-index: 10;
            box-shadow: 0 4px 10px rgba(46, 204, 113, 0.3);
        }
        
        .original-size-message {
            position: absolute;
            bottom: 15px;
            left: 15px;
            background: #2ecc71;
            color: white;
            padding: 8px 15px;
            border-radius: 20px;
            font-size: 13px;
            font-weight: 500;
            z-index: 100;
            box-shadow: 0 4px 10px rgba(46, 204, 113, 0.3);
        }
        
        /* 居中蒙层指示器 */
        .center-guides {
            position: absolute;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            pointer-events: none;
            z-index: 5;
        }
        
        .center-guides .horizontal {
            position: absolute;
            top: 50%;
            left: 0;
            width: 100%;
            height: 1px;
            background: rgba(255, 0, 0, 0.5);
        }
        
        .center-guides .vertical {
            position: absolute;
            left: 50%;
            top: 0;
            width: 1px;
            height: 100%;
            background: rgba(255, 0, 0, 0.5);
        }
        
        .status-message {
            position: fixed;
            top: 20px;
            right: 20px;
            padding: 10px 20px;
            border-radius: 50px;
            background: #2ecc71;
            color: white;
            box-shadow: 0 4px 12px rgba(0,0,0,0.1);
            z-index: 2000;
            transform: translateX(120%);
            transition: transform 0.3s ease;
        }
        
        .status-message.show {
            transform: translateX(0);
        }
        
        .no-preview-message {
            color: #7f8c8d;
            font-size: 16px;
            text-align: center;
            padding: 20px;
        }
        
        .dimension-info {
            display: flex;
            justify-content: space-between;
            font-size: 14px;
            color: #5a6778;
            padding: 8px 0;
            font-weight: 500;
        }
        
        .dimension-label {
            opacity: 0.8;
        }