feat: update toast doc

packages/zanui-css/src/index.css

@@ -25,3 +25,4 @@
 @import './actionsheet.css';
 @import './quantity.css';
 @import './progress.css';
+@import './toast.css';

packages/zanui-css/src/toast.css

@@ -2,30 +2,34 @@
 
 @component-namespace zan {
   @b toast {
+    position: fixed;
     border-radius: 5px;
     background-color: #272727;
     opacity: 0.7;
     top: 50%;
     left: 50%;
     transform: translate3d(-50%, -50%, 0);
-    color: $white;
     font-size: 12px;
+    color: $c-white;
+    text-align: center;
 
     @m loading {
-      .zan-toast__icon {
-        top: 50%;
-        left: 50%;
-        transform: translate3d(-50%, -50%, 0);
-      }
+      padding: 45px;
     }
 
     @m text {
       padding: 11px;
     }
 
-    @m notify {
+    @m default {
+      width: 120px;
+      height: 120px;
       .zan-toast__icon {
         padding: 20px;
+        font-size: 36px;
+      }
+      .zan-toast__text {
+        padding-bottom: 20px;
       }
     }
   }