Centering for tables/images/math in Markdown.

IPython/html/static/notebook/less/renderedhtml.less

@@ -43,7 +43,15
         margin: 1em 2em;
     }
 
-    table, tr, th, td {
+    table {
+        // Center tables horizontally
+        margin-left: auto;
+        margin-right: auto;
+        border: 1px solid black;
+        border-collapse: collapse;
+    }
+
+    tr, th, td {
         border: 1px solid black;
         border-collapse: collapse;
         margin: 1em 2em;
@@ -66,9 +74,16
     p + p {
         margin-top: 1em;
     }
-    
+
+    img {
+        display: block;
+        margin-left: auto;
+        margin-right: auto;
+    }
+
     .MathJax_Display {
-        margin-left: 12ex;
+        text-align: center !important;
+        // margin-left: 12ex;
     }
 
 }

IPython/html/static/style/ipython.min.css

@@ -170,12 +170,14 div.quickhelp{float:left;width:50%;}
 .rendered_html pre{margin:1em 2em;}
 .rendered_html pre,.rendered_html code{border:0;background-color:#ffffff;color:#000000;font-size:100%;padding:0px;}
 .rendered_html blockquote{margin:1em 2em;}
-.rendered_html table,.rendered_html tr,.rendered_html th,.rendered_html td{border:1px solid black;border-collapse:collapse;margin:1em 2em;}
+.rendered_html table{margin-left:auto;margin-right:auto;border:1px solid black;border-collapse:collapse;}
+.rendered_html tr,.rendered_html th,.rendered_html td{border:1px solid black;border-collapse:collapse;margin:1em 2em;}
 .rendered_html td,.rendered_html th{text-align:left;vertical-align:middle;padding:4px;}
 .rendered_html th{font-weight:bold;}
 .rendered_html p{text-align:justify;}
 .rendered_html p+p{margin-top:1em;}
-.rendered_html .MathJax_Display{margin-left:12ex;}
+.rendered_html img{display:block;margin-left:auto;margin-right:auto;}
+.rendered_html .MathJax_Display{text-align:center !important;}
 span#save_widget{padding:0px 5px;margin-top:12px;}
 span#checkpoint_status,span#autosave_status{font-size:small;}
 @media (max-width:767px){span#save_widget{font-size:small;} span#checkpoint_status,span#autosave_status{font-size:x-small;}}@media (max-width:767px){span#checkpoint_status,span#autosave_status{display:none;}}@media (min-width:768px) and (max-width:979px){span#checkpoint_status{display:none;} span#autosave_status{font-size:x-small;}}div.text_cell{padding:5px 5px 5px 5px;}

IPython/html/static/style/style.min.css

@@ -1551,12 +1551,14 div.quickhelp{float:left;width:50%;}
 .rendered_html pre{margin:1em 2em;}
 .rendered_html pre,.rendered_html code{border:0;background-color:#ffffff;color:#000000;font-size:100%;padding:0px;}
 .rendered_html blockquote{margin:1em 2em;}
-.rendered_html table,.rendered_html tr,.rendered_html th,.rendered_html td{border:1px solid black;border-collapse:collapse;margin:1em 2em;}
+.rendered_html table{margin-left:auto;margin-right:auto;border:1px solid black;border-collapse:collapse;}
+.rendered_html tr,.rendered_html th,.rendered_html td{border:1px solid black;border-collapse:collapse;margin:1em 2em;}
 .rendered_html td,.rendered_html th{text-align:left;vertical-align:middle;padding:4px;}
 .rendered_html th{font-weight:bold;}
 .rendered_html p{text-align:justify;}
 .rendered_html p+p{margin-top:1em;}
-.rendered_html .MathJax_Display{margin-left:12ex;}
+.rendered_html img{display:block;margin-left:auto;margin-right:auto;}
+.rendered_html .MathJax_Display{text-align:center !important;}
 span#save_widget{padding:0px 5px;margin-top:12px;}
 span#checkpoint_status,span#autosave_status{font-size:small;}
 @media (max-width:767px){span#save_widget{font-size:small;} span#checkpoint_status,span#autosave_status{font-size:x-small;}}@media (max-width:767px){span#checkpoint_status,span#autosave_status{display:none;}}@media (min-width:768px) and (max-width:979px){span#checkpoint_status{display:none;} span#autosave_status{font-size:x-small;}}div.text_cell{padding:5px 5px 5px 5px;}