Fix .btn-file class

css/AdminLTE.css

@@ -1952,18 +1952,22 @@ Component: timeline
 }
 .btn.btn-file {
   position: relative;
-  width: 120px;
-  height: 35px;
   overflow: hidden;
 }
 .btn.btn-file > input[type='file'] {
-  display: block !important;
-  width: 100% !important;
-  height: 35px !important;
-  opacity: 0 !important;
   position: absolute;
-  top: -10px;
-  cursor: pointer;
+  top: 0;
+  right: 0;
+  min-width: 100%;
+  min-height: 100%;
+  font-size: 100px;
+  text-align: right;
+  filter: alpha(opacity=0);
+  opacity: 0;
+  outline: none;
+  background: white;
+  cursor: inherit;
+  display: block;
 }
 .btn.btn-app {
   position: relative;