Updates to default CSS (#6786)

- Fix margin before codeblock
- Add `monobackgroundcolor` variable, making the background color
  and padding of code optional.
- Ensure that backgrounds from highlighting styles take precedence over
  monobackgroundcolor
- Remove list markers from TOC
- Add margin-bottom where needed
- Remove italics from blockquote styling
- Change borders and spacing in tables to be more consistent with other
   output formats
- Style h5, h6
- Decrease root font-size to 18px
- Update tests for styles.html changes
- Add CSS example to MANUAL

1 files changed, 37 insertions, 8 deletions

diff --git a/test/writer.html5 b/test/writer.html5
index 76ede4cca..cb33a106d 100644
--- a/test/writer.html5
+++ b/test/writer.html5
@@ -12,7 +12,7 @@
     html {
       line-height: 1.7;
       font-family: Georgia, serif;
-      font-size: 20px;
+      font-size: 18px;
       color: #1a1a1a;
       background-color: #fdfdfd;
     }
@@ -48,7 +48,7 @@
       }
     }
     p {
-      margin-top: 1.7em;
+      margin: 1.7em 0;
     }
     a {
       color: #1a1a1a;
@@ -62,6 +62,13 @@
     h1, h2, h3, h4, h5, h6 {
       margin-top: 1.7em;
     }
+    h5, h6 {
+      font-size: 18px;
+      font-style: italic;
+    }
+    h6 {
+      font-weight: normal;
+    }
     ol, ul {
       padding-left: 1.7em;
       margin-top: 1.7em;
@@ -73,7 +80,7 @@
       margin: 1.7em 0 1.7em 1.7em;
       padding-left: 1em;
       border-left: 2px solid #e6e6e6;
-      font-style: italic;
+      color: #606060;
     }
     code {
       font-family: Menlo, Monaco, 'Lucida Console', Consolas, monospace;
@@ -83,6 +90,7 @@
       padding: .2em .4em;
     }
     pre {
+      margin: 1.7em 0;
       line-height: 1.5em;
       padding: 1em;
       background-color: #f0f0f0;
@@ -92,27 +100,48 @@
       padding: 0;
       overflow: visible;
     }
+    .sourceCode {
+     background-color: transparent;
+     overflow: visible;
+    }
     hr {
       background-color: #1a1a1a;
       border: none;
       height: 1px;
-      margin-top: 1.7em;
+      margin: 1.7em 0;
     }
     table {
+      margin: 1.7em 0;
       border-collapse: collapse;
       width: 100%;
       overflow-x: auto;
       display: block;
+      font-variant-numeric: lining-nums tabular-nums;
+    }
+    table caption {
+      margin-bottom: 0.75em;
+    }
+    tbody {
+      border-top: 1px solid #1a1a1a;
+      border-bottom: 1px solid #1a1a1a;
     }
-    th, td {
-      border-bottom: 1px solid lightgray;
-      padding: 1em 3em 1em 0;
+    th {
+      border-top: 1px solid #1a1a1a;
+      padding: 0.25em 0.5em 0.25em 0.5em;
+      line-height: 1;
+    }
+    td {
+      padding: 0.125em 0.5em 0.25em 0.5em;
+      line-height: 1;
     }
     header {
       margin-bottom: 6em;
       text-align: center;
     }
-    nav a:not(:hover) {
+    #TOC li {
+      list-style: none;
+    }
+    #TOC a:not(:hover) {
       text-decoration: none;
     }
     code{white-space: pre-wrap;}