修改issue #12 图片过大加载慢的问题

about.html

@@ -23,9 +23,7 @@
     <!-- 固定导航 -->
     <div id="top_nav" class="header_scroll">
         <div class="main_body clear">
-            <a class="logo left" href="./index.html#header">
-                <img src="./images/logo-02.svg" alt="" class="left">
-            </a>
+            <a class="logo left" href="./index.html#header"></a>
             <div class="nav right">
                 <a class="nav_first" href="./index.html#header">首页</a>
                 <a href="./index.html#introduce">公司介绍</a>

contactus.html

@@ -23,9 +23,7 @@
     <!-- 固定导航 -->
     <div id="top_nav" class="header_scroll">
         <div class="main_body clear">
-            <a class="logo left" href="./index.html#header">
-                <img src="./images/logo-02.svg" alt="" class="left"> 
-            </a>
+            <a class="logo left" href="./index.html#header"></a>
             <div class="nav right">
                 <a class="nav_first" href="./index.html#header">首页</a>
                 <a href="./index.html#introduce">公司介绍</a>

css/index.css

@@ -1326,7 +1326,7 @@
 /* 发展历程 */
 #cours {
     height: 800px;
-    background: url('../images/cours_img.jpg') no-repeat center;
+    background: url('../images/cours_img.png') no-repeat center;
 }
 
 #cours .cours_content {
@@ -1528,7 +1528,7 @@
 
 /* 荣誉资质 */
 #honor {
-    margin-bottom: 80px;
+    /* margin-bottom: 80px; */
 }
 #honor .honor_content {
     text-align: center;