[style] Fix listing connection levels.

scripts/generate.py

@@ -493,11 +493,11 @@ def render_block(content, acc, _class, is_code):
     acc.append('</pre>')
 
 def unindent(content):
-    base_indentation = min([0] + [
+    base_indentation = min([
         len(l) - len(l.lstrip(' '))
         for l in content.split('\n')
         if len(l.strip()) > 0
-    ])
+    ] or [0])
     content_lines = [
         l[base_indentation:]
         for l in content.split('\n')

static/style.css

@@ -263,6 +263,11 @@ img {
     border-left: 2px solid var(--tree-color);
 }
 
+.node .contents ul ul ul li,
+.global-table-of-contents ul ul ul li {
+    margin-left: calc(0px + var(--tree-radius) * 2 + .5ex);
+}
+
 .node .contents ul ul li::marker,
 .global-table-of-contents ul ul li::marker {
     content: '';