diff --git a/.babelrc b/.babelrc
index 1cccc7f..eb5b0c1 100644
--- a/.babelrc
+++ b/.babelrc
@@ -1,6 +1,6 @@
 {
   "plugins": [
-    "@babel/plugin-proposal-optional-chaining"
+    "@babel/plugin-proposal-class-properties"
   ],
   "presets": [
     ["@babel/preset-env", {
@@ -8,7 +8,7 @@
       "targets": {
         "esmodules": true,
       },
-    }]
+    }],
   ]
 }
 // {
diff --git a/package-lock.json b/package-lock.json
index 28c0672..3da715c 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -421,12 +421,111 @@
       }
     },
     "@babel/plugin-proposal-class-properties": {
-      "version": "7.10.4",
-      "resolved": "https://registry.npmjs.org/@babel/plugin-proposal-class-properties/-/plugin-proposal-class-properties-7.10.4.tgz",
-      "integrity": "sha512-vhwkEROxzcHGNu2mzUC0OFFNXdZ4M23ib8aRRcJSsW8BZK9pQMD7QB7csl97NBbgGZO7ZyHUyKDnxzOaP4IrCg==",
+      "version": "7.12.1",
+      "resolved": "https://registry.npmjs.org/@babel/plugin-proposal-class-properties/-/plugin-proposal-class-properties-7.12.1.tgz",
+      "integrity": "sha512-cKp3dlQsFsEs5CWKnN7BnSHOd0EOW8EKpEjkoz1pO2E5KzIDNV9Ros1b0CnmbVgAGXJubOYVBOGCT1OmJwOI7w==",
       "requires": {
-        "@babel/helper-create-class-features-plugin": "^7.10.4",
+        "@babel/helper-create-class-features-plugin": "^7.12.1",
         "@babel/helper-plugin-utils": "^7.10.4"
+      },
+      "dependencies": {
+        "@babel/generator": {
+          "version": "7.12.11",
+          "resolved": "https://registry.npmjs.org/@babel/generator/-/generator-7.12.11.tgz",
+          "integrity": "sha512-Ggg6WPOJtSi8yYQvLVjG8F/TlpWDlKx0OpS4Kt+xMQPs5OaGYWy+v1A+1TvxI6sAMGZpKWWoAQ1DaeQbImlItA==",
+          "requires": {
+            "@babel/types": "^7.12.11",
+            "jsesc": "^2.5.1",
+            "source-map": "^0.5.0"
+          }
+        },
+        "@babel/helper-create-class-features-plugin": {
+          "version": "7.12.1",
+          "resolved": "https://registry.npmjs.org/@babel/helper-create-class-features-plugin/-/helper-create-class-features-plugin-7.12.1.tgz",
+          "integrity": "sha512-hkL++rWeta/OVOBTRJc9a5Azh5mt5WgZUGAKMD8JM141YsE08K//bp1unBBieO6rUKkIPyUE0USQ30jAy3Sk1w==",
+          "requires": {
+            "@babel/helper-function-name": "^7.10.4",
+            "@babel/helper-member-expression-to-functions": "^7.12.1",
+            "@babel/helper-optimise-call-expression": "^7.10.4",
+            "@babel/helper-replace-supers": "^7.12.1",
+            "@babel/helper-split-export-declaration": "^7.10.4"
+          }
+        },
+        "@babel/helper-member-expression-to-functions": {
+          "version": "7.12.7",
+          "resolved": "https://registry.npmjs.org/@babel/helper-member-expression-to-functions/-/helper-member-expression-to-functions-7.12.7.tgz",
+          "integrity": "sha512-DCsuPyeWxeHgh1Dus7APn7iza42i/qXqiFPWyBDdOFtvS581JQePsc1F/nD+fHrcswhLlRc2UpYS1NwERxZhHw==",
+          "requires": {
+            "@babel/types": "^7.12.7"
+          }
+        },
+        "@babel/helper-replace-supers": {
+          "version": "7.12.11",
+          "resolved": "https://registry.npmjs.org/@babel/helper-replace-supers/-/helper-replace-supers-7.12.11.tgz",
+          "integrity": "sha512-q+w1cqmhL7R0FNzth/PLLp2N+scXEK/L2AHbXUyydxp828F4FEa5WcVoqui9vFRiHDQErj9Zof8azP32uGVTRA==",
+          "requires": {
+            "@babel/helper-member-expression-to-functions": "^7.12.7",
+            "@babel/helper-optimise-call-expression": "^7.12.10",
+            "@babel/traverse": "^7.12.10",
+            "@babel/types": "^7.12.11"
+          },
+          "dependencies": {
+            "@babel/helper-optimise-call-expression": {
+              "version": "7.12.10",
+              "resolved": "https://registry.npmjs.org/@babel/helper-optimise-call-expression/-/helper-optimise-call-expression-7.12.10.tgz",
+              "integrity": "sha512-4tpbU0SrSTjjt65UMWSrUOPZTsgvPgGG4S8QSTNHacKzpS51IVWGDj0yCwyeZND/i+LSN2g/O63jEXEWm49sYQ==",
+              "requires": {
+                "@babel/types": "^7.12.10"
+              }
+            }
+          }
+        },
+        "@babel/helper-validator-identifier": {
+          "version": "7.12.11",
+          "resolved": "https://registry.npmjs.org/@babel/helper-validator-identifier/-/helper-validator-identifier-7.12.11.tgz",
+          "integrity": "sha512-np/lG3uARFybkoHokJUmf1QfEvRVCPbmQeUQpKow5cQ3xWrV9i3rUHodKDJPQfTVX61qKi+UdYk8kik84n7XOw=="
+        },
+        "@babel/parser": {
+          "version": "7.12.11",
+          "resolved": "https://registry.npmjs.org/@babel/parser/-/parser-7.12.11.tgz",
+          "integrity": "sha512-N3UxG+uuF4CMYoNj8AhnbAcJF0PiuJ9KHuy1lQmkYsxTer/MAH9UBNHsBoAX/4s6NvlDD047No8mYVGGzLL4hg=="
+        },
+        "@babel/traverse": {
+          "version": "7.12.10",
+          "resolved": "https://registry.npmjs.org/@babel/traverse/-/traverse-7.12.10.tgz",
+          "integrity": "sha512-6aEtf0IeRgbYWzta29lePeYSk+YAFIC3kyqESeft8o5CkFlYIMX+EQDDWEiAQ9LHOA3d0oHdgrSsID/CKqXJlg==",
+          "requires": {
+            "@babel/code-frame": "^7.10.4",
+            "@babel/generator": "^7.12.10",
+            "@babel/helper-function-name": "^7.10.4",
+            "@babel/helper-split-export-declaration": "^7.11.0",
+            "@babel/parser": "^7.12.10",
+            "@babel/types": "^7.12.10",
+            "debug": "^4.1.0",
+            "globals": "^11.1.0",
+            "lodash": "^4.17.19"
+          },
+          "dependencies": {
+            "@babel/helper-split-export-declaration": {
+              "version": "7.12.11",
+              "resolved": "https://registry.npmjs.org/@babel/helper-split-export-declaration/-/helper-split-export-declaration-7.12.11.tgz",
+              "integrity": "sha512-LsIVN8j48gHgwzfocYUSkO/hjYAOJqlpJEc7tGXcIm4cubjVUf8LGW6eWRyxEu7gA25q02p0rQUWoCI33HNS5g==",
+              "requires": {
+                "@babel/types": "^7.12.11"
+              }
+            }
+          }
+        },
+        "@babel/types": {
+          "version": "7.12.11",
+          "resolved": "https://registry.npmjs.org/@babel/types/-/types-7.12.11.tgz",
+          "integrity": "sha512-ukA9SQtKThINm++CX1CwmliMrE54J6nIYB5XTwL5f/CLFW9owfls+YSU8tVW15RQ2w+a3fSbPjC6HdQNtWZkiA==",
+          "requires": {
+            "@babel/helper-validator-identifier": "^7.12.11",
+            "lodash": "^4.17.19",
+            "to-fast-properties": "^2.0.0"
+          }
+        }
       }
     },
     "@babel/plugin-proposal-dynamic-import": {
@@ -9799,9 +9898,9 @@
       }
     },
     "lodash": {
-      "version": "4.17.19",
-      "resolved": "https://registry.npmjs.org/lodash/-/lodash-4.17.19.tgz",
-      "integrity": "sha512-JNvd8XER9GQX0v2qJgsaN/mzFCNA5BRe/j8JN9d+tWyGLSodKQHKFicdwNYzWwI3wjRnaKPsGj1XkBjx/F96DQ=="
+      "version": "4.17.20",
+      "resolved": "https://registry.npmjs.org/lodash/-/lodash-4.17.20.tgz",
+      "integrity": "sha512-PlhdFcillOINfeV7Ni6oF1TAEayyZBoZ8bcshTHqOYJYlrqzRK5hagpagky5o4HfCzzd1TRkXPMFq6cKk9rGmA=="
     },
     "lodash._reinterpolate": {
       "version": "3.0.0",
diff --git a/package.json b/package.json
index 41cd381..7da10e4 100644
--- a/package.json
+++ b/package.json
@@ -20,6 +20,7 @@
     "start": "npm run dev"
   },
   "dependencies": {
+    "@babel/plugin-proposal-class-properties": "^7.12.1",
     "@types/core-js": "^2.5.3",
     "@types/es6-promise": "^3.3.0",
     "@vue/cli": "^4.5.9",