gitlab-org--gitlab-foss/app/assets/stylesheets/notes.scss

/**
 * Notes
 *
 */
#notes-list, 
#new_notes_list {
  display:block;
  list-style:none;
  margin:0px;
  padding:0px;
}

#new_notes_list li:last-child{ 
  border-bottom:1px solid #aaa;
}

.issue_notes {
  .note_content {
    float:left;
    width:400px;
  }
}

/* Note textare */
#note_note {
  height:100px;
  width:97%;
  font-size:14px;
}

#new_note {
  #note_note {
    height:25px;
  }
  .attach_holder {
    display:none;
  }
}

.note .delete-note { 
  display:none; 
  float:right;
}
.note:hover .delete-note { display:block; }
.note {padding: 10px 0; border-bottom: 1px solid #eee; overflow: hidden; display: block;}
.note img{float: left; margin-right: 10px;}
.note span.note-title{display: block;}
.note span.note-title{margin-bottom: 10px}
.note span.note-author{color: #999; font-weight: normal; font-style: italic;}
.note span.note-author strong{font-weight: bold; font-style: normal;}
.note p { color:$style_color; }
.note .note-author { color: $style_color;}

.note .note-title { margin-left:55px; }

p.notify_controls input{
  margin: 5px;
}

p.notify_controls span{
  font-weight: 700;
}

tr.line_notes_row { 
  border-bottom:1px solid #DDD;
  &.reply { 
    background:#eee;

    td { 
      padding:7px 10px;
    }
    a.line_note_reply_link { 
      @include round-borders-all(4px);
      border-color:#aaa;
      background: #bbb;
      padding: 3px 20px;
      color: white;
    }
  }
  ul { 
    margin:0;
    li { 
      padding:0;
      border:none;
    }
  }
}

.line_notes_row,  .per_line_form { font-family: "Helvetica Neue", Helvetica, Arial, sans-serif; }

.per_line_form { 
  background:#f5f5f5;
  border-top:1px solid #eee;
  form {  margin: 0; }
  td { 
    border-bottom:1px solid #ddd;
  }
}

td .line_note_link { 
  position:absolute;
  margin-left:-70px;
  margin-top:-10px;
  z-index:10;
  background: url("comment_add.png") no-repeat left 0;
  width:32px;
  height:32px;

  opacity: 0.0;
  filter: alpha(opacity=0);

  &:hover { 
    opacity: 1.0;
    filter: alpha(opacity=100);
  }
}

.diff_file_content tr.line_holder:hover > td { background: $hover !important; }
.diff_file_content tr.line_holder:hover > td .line_note_link { 
  opacity: 1.0;
  filter: alpha(opacity=100);
}