add pic grid and basic pure css support

static/css/style.css

@@ -14,11 +14,14 @@ body{
     }
 }
 
-.bodycontainer{
+.container{
     max-width: 760px;
-    /* padding-right: 80px; */
+    margin: auto;
 }
 
+.moment-content{
+    position: relative;
+}
 /* 时间 */
 .time{
     text-align: right;
@@ -78,14 +81,27 @@ body{
     margin-top: 5px; 
 }
 /* 图片集 */
-#carouselExampleIndicators{
-    width: 80%; 
-    padding-bottom:10px;
-    margin-top: 5px;
+.pic-grid{
+    max-width: 80%;
 }
 
-.pic-in-set{
-    height: 250px;
+.pic-grid .img-container{
+    padding-top: 50%;
+    padding-bottom: 50%;
+    position: relative;
+    height: 0px;
+}
+
+.pic-grid img{
+    object-fit: cover;
+    height: 100%;
+    width: 100%;
+    position: absolute;
+    top: 0
+}
+
+.pic-grid .add-padding{
+    padding: 2.5px;
 }
 
 /* 内容附带的超链接 */