This Userstyles fill the windows in a multicolumn page (based on window size) .

You can use too the enable options of DuckDuckGo to format the result page:
Many options are provided and you can save your preferences too.
For me on a large screen , this is 3 columns.

If you want less or more columns, you can play with the width variable of :
#links .result
(find it in my userstyles and play )
By example to have 2 columns:

#links .result {
min-height : 155px ! important;
max-height : 155px ! important;
min-width : 45% ! important;
max-width : 45% ! important;
margin-right: 4px ! important;
padding: 1px 1px 1px 35px ! important;
border: 1px solid gray ! important;
}

Also to see the leftside panel colored (with the checkmark to show if the result was or not visited before),
use the Dark/Gray Light or the Dark theme .
See the screenshot here:
https://forum.userstyles.org/discussion/46458/wow-looks-amazing#latest

NEW in
v.8: Support for the Top Info Sidebar (Expand on Hover).
Test Links:
https://duckduckgo.com/?q=wikipedia&t=ffsb&ia=web
https://duckduckgo.com/?q=metaKey&t=ffsb&ia=web
https://duckduckgo.com/?q=microsoft&t=ffsb&ia=places

v.7: correction for columns...
v.6 : Mark text links "Linkifyed" by GM "https://greasyfork.org/en/scripts/4255-linkify-plus-plus"
v.5 : Auto load work now
v.4:
Adaptation for GM https://greasyfork.org/en/scripts/4255-linkify-plus-plus in use.
test link :
https://duckduckgo.com/?q=ShowAllGroups - by vispillo