fix: 解决input组件半透明背景显示异常的问题

src/core/view/components/input/index.vue

 <template>
   <uni-input v-on="$listeners">
-    <div
-      ref="wrapper"
+    <div
+      ref="wrapper"
       :disabled="disabled">
-      <input
-        ref="input"
-        v-model="inputValue"
-        :disabled="disabled"
-        :type="inputType"
-        :maxlength="maxlength"
+      <input
+        ref="input"
+        v-model="inputValue"
+        :disabled="disabled"
+        :type="inputType"
+        :maxlength="maxlength"
         :step="step"
-        @focus="_onFocus"
-        @blur="_onBlur"
-        @input.stop="_onInput"
-        @compositionstart="_onComposition"
+        @focus="_onFocus"
+        @blur="_onBlur"
+        @input.stop="_onInput"
+        @compositionstart="_onComposition"
         @compositionend="_onComposition"
         @keyup.stop="_onKeyup">
-      <div
-        v-show="!(composing || inputValue.length)"
-        ref="placeholder"
-        :style="placeholderStyle"
+      <div
+        v-show="!(composing || inputValue.length)"
+        ref="placeholder"
+        :style="placeholderStyle"
         :class="placeholderClass"
         class="input-placeholder">{{ placeholder }}</div>
     </div>
-    <v-uni-resize-sensor
-      ref="sensor"
+    <v-uni-resize-sensor
+      ref="sensor"
       @resize="_resize" />
   </uni-input>
 </template>
@@ -405,6 +405,7 @@ export default {
 		color: gray;
 		height: inherit;
 		line-height: inherit;
+    background: none;
 	}
 
 	input[type="search"]::-webkit-search-cancel-button {
@@ -420,4 +421,4 @@ export default {
 	input[type="number"] {
 		-moz-appearance: textfield;
 	}
-</style>
+</style>