* tutorial: optimize start stuorial modal style.

module/tutorial/css/start.ui.css

@@ -5,7 +5,4 @@
 .start-icon .icon2{font-size: 56px; position: absolute; top: 35px; left: 42px; color: #EBF2F9; z-index: 10; width: 70px; height: 70px; text-align: center; line-height: 70px; text-shadow: 0 1px 3px rgb(0,0,0,.15);}
 #start > h1, #start > p {margin-bottom: 30px;}
 h1{font-size: 24px;}
-.btn-start-now{min-width: 120px; height: 42px;}
-.btn-lg{padding: 11px 16px; font-size: 14px; line-height: 18px; border-radius: 4px;}
-.btn-info{color: #2e7fff; background-color: #e6f0ff; border-color: transparent;}
 #startModal .modal-body {padding: 0; margin-top: 0;}

module/tutorial/ui/start.html.php

@@ -25,7 +25,7 @@ div
     h1($lang->tutorial->common),
     p($lang->tutorial->desc),
     a(
-        setClass('btn btn-default btn-start-now btn-lg btn-info'),
+        setClass('btn w-28 canvas size-lg text-primary'),
         set::href($this->inlink('index')),
         set::target('_top'),
         span($lang->tutorial->start)