When I check the source and click the link...
<link rel="stylesheet" href="
/wordpress/forums/css.php?css=public%3Anode_list.less%2Cpublic%3Ashare_controls.less%2Cpublic%3Aextra.less&s=2&l=1&d=1576783116&k=b05daa783826eef971bb737ac19714740693ecd0" />
and check where the extra.less is being called. Others seem to come up like so...
/********* public:node_list.less ********/
.node+.node{border-top:1px solid #280001}.node-body{display:table;table-layout:fixed;width:100%}.node-icon{display:table-cell;vertical-align:middle;text-align:center;width:46px;padding:10px 0 10px 10px}.node-icon i{display:block;line-height:1.125;font-size:32px}.node-icon i:before{font-family:'Font Awesome 5 Pro';font-size:inherit;font-style:normal;font-weight:400;text-rendering:auto;-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale;color:#610103}.node--unread .node-icon i:before{opacity:1;color:#ab0003}.node--forum .node-icon i:before,.node--category .node-icon i:before{content:"\f086"}.node--page .node-icon i:before{content:"\f15c"}.node--link .node-icon i:before{content:"\f0c1"}.node-main{display:table-cell;vertical-align:middle;padding:10px}.node-stats{display:table-cell;width:140px;vertical-align:middle;text-align:center;padding:10px 0}.node-stats>dl.pairs.pairs--rows{width:50%;float:left;margin:0;padding:0 3px}.node-stats>dl.pairs.pairs--rows:first-child{padding-left:0}.node-stats>dl.pairs.pairs--rows:last-child{padding-right:0}.node-stats.node-stats--single{width:100px}.node-stats.node-stats--single>dl.pairs.pairs--rows{width:100%;float:none}.node-stats.node-stats--triple{width:240px}.node-stats.node-stats--triple>dl.pairs.pairs--rows{width:33.333%}@media (max-width:1000px){.node-stats{display:none}}.node-extra{display:table-cell;vertical-align:middle;width:280px;padding:10px;font-size:13px}.node-extra-row{overflow:hidden;white-space:nowrap;word-wrap:normal;text-overflow:ellipsis;color:#bebebe}.node-extra-icon{padding-right:10px;float:left}.node-extra-icon .avatar{width:36px;height:36px;font-size:22px}.node-extra-placeholder{font-style:italic}.node-title{margin:0;padding:0;font-size:17px;font-weight:400}.node--unread .node-title{font-weight:700}.node-description{font-size:13px;color:#dfdfdf}.has-js:not(.has-touchevents) .node-description.node-description--tooltip{display:none}.node-meta{font-size:13px}.node-statsMeta{display:none}@media (max-width:1000px){.node-statsMeta{display:inline}}.node-bonus{font-size:13px;color:#bebebe;text-align:right}.node-subNodesFlat{font-size:13px;margin-top:.3em}.node-subNodesFlat .node-subNodesLabel{display:none}.node-subNodeMenu{display:inline}.node-subNodeMenu .menuTrigger{color:#bebebe}@media (max-width:650px){.node-main{display:block;width:auto}.node--link .node-main,.node--page .node-main{display:table-cell}.node-extra{display:block;width:auto;margin-top:-4px;padding-top:0}.node-extra-row{display:inline-block;vertical-align:top;max-width:100%}.node-extra-icon{display:none}.node-description,.node-stats,.node-subNodesFlat{display:none}}@media (max-width:480px){.node-subNodeMenu{display:none}}.subNodeLink:before{display:inline-block;font-family:'Font Awesome 5 Pro';font-size:inherit;font-style:normal;font-weight:400;text-rendering:auto;-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale;width:1em;padding-right:.3em;text-decoration:none;color:#610103}.subNodeLink:hover:before{text-decoration:none}.subNodeLink.subNodeLink--unread{font-weight:700}.subNodeLink.subNodeLink--unread:before{color:#ab0003}.subNodeLink.subNodeLink--forum:before,.subNodeLink.subNodeLink--category:before{content:"\f086"}.subNodeLink.subNodeLink--page:before{content:"\f15c"}.subNodeLink.subNodeLink--link:before{content:"\f0c1"}.node-subNodeFlatList{list-style:none;margin:0;padding:0}.node-subNodeFlatList:before,.node-subNodeFlatList:after{content:" ";display:table}.node-subNodeFlatList:after{clear:both}.node-subNodeFlatList>li{display:inline-block;margin-right:1em}.node-subNodeFlatList>li:last-child{margin-right:0}.node-subNodeFlatList ol,.node-subNodeFlatList ul,.node-subNodeFlatList .node-subNodes{display:none}.subNodeMenu{list-style:none;margin:0;padding:0}.subNodeMenu ol,.subNodeMenu ul{list-style:none;margin:0;padding:0}.subNodeMenu .subNodeLink{display:block;padding:6px 10px;text-decoration:none;cursor
ointer}.subNodeMenu .subNodeLink:hover{text-decoration:none;background:#490001}.subNodeMenu li li .subNodeLink{padding-left:1.5em}.subNodeMenu li li li .subNodeLink{padding-left:3em}.subNodeMenu li li li li .subNodeLink{padding-left:4.5em}.subNodeMenu li li li li li .subNodeLink{padding-left:6em}.subNodeMenu li li li li li li .subNodeLink{padding-left:7.5em}
/********* public:share_controls.less ********/
.shareButtons:before,.shareButtons:after{content:" ";display:table}.shareButtons:after{clear:both}.shareButtons--iconic .shareButtons-buttons{display:grid;grid-template-columns:repeat(auto-fill, minmax(35px, 1fr))}.shareButtons-label{float:left;margin-right:3px;color:#bebebe;min-height:35px;line-height:35px}.shareButtons-button{float:left;margin-right:3px;padding:6px;color:#bebebe;font-size:20px;line-height:20px;white-space:nowrap;min-width:35px;border-radius:2px;background-color:transparent;-webkit-transition: all .25s ease;transition: all .25s ease}.shareButtons-button:last-of-type{margin-right:0}.shareButtons-button:hover{text-decoration:none;color:white}.shareButtons-button>i{display:inline-block;vertical-align:middle;font-family:'Font Awesome 5 Pro';font-size:inherit;font-style:normal;font-weight:400;text-rendering:auto;-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale}.shareButtons-button.shareButtons-button--brand>i{font-family:'Font Awesome 5 Brands';font-size:inherit;font-style:normal;font-weight:400;text-rendering:auto;-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale}.shareButtons-button>span{font-weight:400;font-size:15px}.shareButtons--iconic .shareButtons-button{text-align:center}.shareButtons--iconic .shareButtons-button>i{min-width:20px}.shareButtons--iconic .shareButtons-button>span{position:absolute;height:1px;width:1px;margin:-1px;padding:0;border:0;clip:rect(0 0 0 0);overflow:hidden}.shareButtons-button.shareButtons-button--facebook:hover{background-color:#3B5998}.shareButtons-button.shareButtons-button--facebook>i:before{content:"\f39e"}.shareButtons-button.shareButtons-button--twitter:hover{background-color:#1DA1F3}.shareButtons-button.shareButtons-button--twitter>i:before{content:"\f099"}.shareButtons-button.shareButtons-button--pinterest:hover{background-color:#bd081c}.shareButtons-button.shareButtons-button--pinterest>i:before{content:"\f231"}.shareButtons-button.shareButtons-button--tumblr:hover{background-color:#35465c}.shareButtons-button.shareButtons-button--tumblr>i:before{content:"\f173"}.shareButtons-button.shareButtons-button--reddit:hover{background-color:#FF4500}.shareButtons-button.shareButtons-button--reddit>i:before{content:"\f281"}.shareButtons-button.shareButtons-button--whatsApp:hover{background-color:#25D366}.shareButtons-button.shareButtons-button--whatsApp>i:before{content:"\f232"}.shareButtons-button.shareButtons-button--email:hover{background-color:#1289ff}.shareButtons-button.shareButtons-button--email>i:before{content:"\f0e0"}.shareButtons-button.shareButtons-button--link{cursor
ointer}.shareButtons-button.shareButtons-button--link:hover{background-color:#787878}.shareButtons-button.shareButtons-button--link>i:before{content:"\f0c1"}.shareButtons-button.is-hidden{display:none}.shareInput{margin-bottom:5px}.shareInput:last-child{margin-bottom:0}.shareInput-label{font-size:13px}.shareInput-label:after{content:":"}.shareInput-label.is-sentence:after{content:""}.shareInput-button{color:#e64006;cursor
ointer}.shareInput-button>i{display:inline-block;vertical-align:middle;font-family:'Font Awesome 5 Pro';font-size:inherit;font-style:normal;font-weight:400;text-rendering:auto;-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale}.shareInput-button>i:before{content:"\f0c5"}.shareInput-button.is-hidden{display:none}.shareInput-input{font-size:13px}@media (max-width:568px){.shareInput-input{font-size:16px}}.shareInput-button.is-hidden+.shareInput-input{border-radius:4px}
But there is no extra.css heading there.