diff --git a/src/App.vue b/src/App.vue
index 771530578b572a3837aaff979dbc7b974b48ee14..23c42a95e7dc002fd337f1c5883758cd02beab27 100644
--- a/src/App.vue
+++ b/src/App.vue
@@ -27,12 +27,18 @@ onMounted(confirm)
 function confirm() {
   isWin = []
   lattices.value = Array(size.value).fill([]).map(() => Array(size.value).fill(is_empty))
+  records.value = []
 }
-function back(){
-  Array(2)
+function back() {
+  if (records.value.length < 2) return;
+  for (let i = 0; i < 2; i++) {
+    const { location: [y, x] } = records.value.pop()
+    lattices.value[y][x] = is_empty
+  }
+  isWin = []
 }
 
-function setPiece([y, x], type){
+function setPiece([y, x], type) {
   records.value.push({
     location: [y, x],
     type: type
@@ -70,7 +76,7 @@ async function playChess(item, row, col) {
       <label for="win_size" class="space-nowrap">胜利棋数：</label>
       <input v-model="win_size" id="win_size" type="number" min="3" max="8">
     </p>
-    <button @click="confirm" class="space-nowrap">重新开始</button>
+    <button @click="confirm" class="space-nowrap mr-6px">重新开始</button>
     <button @click="back" class="space-nowrap">返回上一步</button>
   </div>
   <div class="content border-top content-lattice">
diff --git a/src/assets/main.css b/src/assets/main.css
index bbe49b6c05341f2c013da3763c262a1da34f995c..d0be9a2a558f25a2a06203c3d4541525d897d53f 100644
--- a/src/assets/main.css
+++ b/src/assets/main.css
@@ -12,8 +12,6 @@ body,
 }
 
 #app {
-  margin: 0 auto;
-
   font-weight: normal;
   cursor: pointer;
 }