tabs.css

body {
  font-family: Lucida Grande, sans-serif;
  background: #ccc;
}
.icon {
  height: 32px;
  max-width: 32px;
  border-radius: 6px;
  position: absolute;
}
.row {
  height: 26px;
  opacity: 1;
  transition: .1s;
}
.tab {
  font-size: 12px;
  margin-left: 40px;
  max-width: 100%;
  display: inline-block;
}
.tab.active {
  box-shadow: 0 0 4px #08f;
}
.group {
  -webkit-column-break-inside: avoid;
  padding-top: 2px;
  padding-bottom: 14px;
  position: relative;
  white-space: nowrap;
  width: 450px;
  opacity: 1;
  transition: .1s;
}
.grouptitle {
  font-weight: bold;
  font-size:14px;
  height: 24px;
  transition: .1s;
}
.title {
  display:inline-block;
  background: #fff;
  border-radius: 3px;
  padding: 4px;
  cursor: pointer;
  max-width: 100%;
  overflow: hidden;
  text-overflow: ellipsis;
  vertical-align: bottom;
}
.title .match {
  font-weight: bold;
  color: #06f;
}
.tab .title.incognito {
  background: #88a;
  color: #fff;
}
.tab[hilite] .title {
  background: #ffc;
  color: #000;
}
.row[data-selected=true] .title {
  background: #dff;
}
.close::before {
  content: "";
  width: 16px;
  height: 16px;
  background: red;
  display: block;
  position: relative;
  top: -4px;
  left: -8px;
  border-radius: 8px;
}
.close::after {
  content: "";
  width: 10px;
  height: 2px;
  background: #fff;
  display: block;
  position: relative;
  top: -13px;
  left: -5px;
}
.close {
  position: absolute;
  display: inline-block;
  visibility: hidden;
  opacity: 0;
  transition: opacity 0s 0s, visibility 0s 0s;
  cursor: pointer;
}
.tab:hover .close {
  visibility: inherit;
  opacity: 1;
  transition: opacity .1s .1s, visibility 0s .1s;
}
.row[data-show=false] {
  height: 0px;
  opacity: 0;
  pointer-events: none;
}
.group[data-show=false] {
  padding-top: 0;
  padding-bottom: 0;
  opacity: 0;
  pointer-events: none;
}
.group[data-show=false] .grouptitle {
  height: 0;
}
#matchtext {
  color: #06f;
  font-weight: bold;
  margin-bottom: 12px;
  display: none;
}
#matchtext[shown] {
  display: block;
}
#matchtext::before, #matchtext::after {
  color: #000;
  font-weight: normal;
}
#matchtext::after {
  content: ".";
}
#matchtext[shown=some]::before {
  content: "Tabs matching ";
}
#matchtext[shown=none]::before {
  content: "No tabs match ";
}