Tweak precedence table styles a bit.

doc/site/style.scss

@@ -290,10 +290,26 @@ body.core {
   }
 }
 
+table {
+  width: 100%;
+  border-collapse: collapse;
+
+  tr {
+    margin: 0;
+    padding: 0;
+    vertical-align: top;
+  }
+
+  th, td {
+    font-size: 14px;
+    line-height: 20px;
+    text-align: left;
+  }
+}
+
 // Bar charts on the performance page.
 table.chart {
-  width: 100%;
-  padding-left: 25px;
+  padding: 5px 0 5px 25px;
 
   td, th {
     line-height: 14px;
@@ -303,7 +319,6 @@ table.chart {
 
   th {
     font-size: 14px;
-    text-align: left;
     width: 100px;
   }
 
@@ -325,18 +340,9 @@ table.chart {
 
 // Precedence table on expressions page.
 table.precedence {
-  width: 100%;
-  padding-left: 25px;
-
   tr {
-    margin: 0;
-    padding: 0;
-  }
-
-  th, td {
-    font-size: 14px;
-    line-height: 20px;
-    text-align: left;
+    padding: 2px 0;
+    border-bottom: solid 1px $gray-10;
   }
 }