分割线不显示时，宽度为0

src/views/book/courseware/preview/components/divider/DividerPreview.vue

@@ -21,7 +21,7 @@ export default {
         margin: `${this.data.property.height / 2}px auto`,
         border: 'none',
         borderTop: `1px ${this.data.property.line_type} ${this.data.property.color}`,
-        width: `${this.data.property.width}px`,
+        width: `${this.data.property.line_type === 'none' ? 'auto' : `${this.data.property.width}px`}`,
       };
     },
     settingWavyStyle() {