redmine/public/stylesheets/context_menu.css

#context-menu { position: absolute; z-index: 40; font-size: 0.9em;}

#context-menu ul, #context-menu li, #context-menu a {
  display:block;
  margin:0;
  padding:0;
  border:0;
}

#context-menu ul {
  width:150px;
  border: 1px solid #ccc;
  background:white;
  list-style:none;
  padding:2px;
  border-radius:2px;
}

#context-menu li {
  position:relative;
  padding:1px;
  z-index:39;
  border:1px solid white;
}
#context-menu li.folder ul { position:absolute; left:168px; /* IE6 */ top:-2px; max-height:300px; overflow:hidden; overflow-y: auto; }
#context-menu li.folder>ul { left:148px; }

#context-menu.reverse-y li.folder>ul, #context-menu li.folder.up>ul { top:auto; bottom:0; }
#context-menu.reverse-x li.folder ul { left:auto; right:168px; /* IE6 */ }
#context-menu.reverse-x li.folder>ul { right:148px; }

#context-menu.reverse-y li.folder.down>ul {
  position:absolute; top:-2px; bottom: auto; max-height:300px; overflow:hidden; overflow-y: auto;
}

#context-menu a {
  text-decoration:none !important;
  padding: 2px 0px 2px 20px;
  width:100%; /* IE */
}
#context-menu li>a { width:auto; } /* others */
#context-menu a.disabled, #context-menu a.disabled:hover {color: #aaa;}
#context-menu li a.submenu { padding-right:16px; background:url("../images/arrow_right.png") right no-repeat; }
#context-menu li:hover { border:1px solid #628db6; background-color:#eef5fd; border-radius:3px; }
#context-menu a:hover {color:#2A5685;}
#context-menu li.folder:hover { z-index:40; }
#context-menu ul ul, #context-menu  li:hover ul ul { display:none; }
#context-menu li:hover ul, #context-menu li:hover li:hover ul { display:block; }
#context-menu a.icon-checked {background: url(../images/toggle_check.png) no-repeat 3px 40%;}

/* selected element */
.context-menu-selection { background-color:#507AAA !important; color:#f8f8f8 !important; }
.context-menu-selection a, .context-menu-selection a:hover { color:#f8f8f8 !important; }
.context-menu-selection:hover { background-color:#507AAA !important; color:#f8f8f8  !important; }
div#gantt_area .context-menu-selection { background-color: rgba(80, 122, 170, 0.48) !important; }
div#gantt_area .context-menu-selection:hover { background-color: rgba(80, 122, 170, 0.48) !important; }
div#gantt_area .context-menu-selection a { color: #169 !important; }