style.css

body, html {
  background: rgb(29, 29, 29);
  font-family: 'Open Sans', sans-serif;
  overflow: hidden;
  user-select: none;
  margin: 0;
}

#canvas {
  border: 1px solid #a0a0a0;
}

#canvas, #ui-menu {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
}

button {
  outline: none;
  cursor: pointer;
  border: none;
}

/* UI */
#ui-menu {
  display: block;
  pointer-events: all;
  z-index: 999;
  width: 860px;
  height: 560px;
}

#ui-menu-title {
  position: relative;
  text-align: center;
  font-size: 41px;
  top: -10px;
  color: white;
}

#ui-button-back {
  position: absolute;
  display: none;
  top: 0;
  width: 35px;
  height: 35px;
  transition: .15s;
  background: rgb(46, 46, 46);
}

#ui-button-back>.fa-angle-left {
  font-size: 30px;
  padding-right: 1px;
  color: white;
}

#ui-menu-content {
  position: absolute;
  top: 100px;
  width: 670px;
  left: 50%;
  opacity: 1;
  transform: translateX(-50%);
}

#ui-menu-panel-main, #ui-menu-panel-matchSettings, #ui-menu-panel-gameSettings, #ui-menu-panel-historyMatch, #ui-menu-panel-updateList {
  position: relative;
  width: 100%;
  display: flex;
  justify-content: center;
  align-items: center;
}

#ui-menu-panel-matchSettings, #ui-menu-panel-gameSettings, #ui-menu-panel-historyMatch, #ui-menu-panel-updateList {
  flex-wrap: wrap;
}

#ui-menu-panel-main-left, #ui-menu-panel-main-right {
  width: 50%;
}

#ui-menu-panel-main-right {
  text-align: right;
}

.ui-button-panel-menu {
  width: 95%;
  transition: .15s;
  color: white;
  font-size: 20px;
  height: 63px;
  margin: 8px;
  letter-spacing: 1px;
  outline: 2px solid rgb(65, 65, 65);
  background: rgb(46, 46, 46);
}

.ui-button-panel-menu.start {
  font-size: 45px;
  letter-spacing: 5px;
  height: 300px;
}

.ui-button-panel-menu.start:hover {
  box-shadow: inset 0 0 8px 2px rgba(83, 255, 44, 0.5);
  outline: 3px solid rgb(83, 255, 44);
}

.ui-button-panel-menu.exit {
  font-size: 27px;
  letter-spacing: 2px;
}

.ui-button-panel-menu.exit:hover {
  box-shadow: inset 0 0 8px 2px rgba(255, 40, 40, .5);
  outline: 3px solid rgb(255, 40, 40);
}


.unavailable {
  opacity: .2;
  background: rgb(61, 0, 0);
  outline: 2px solid rgb(184, 1, 1);
}

.other {
  outline: 2px solid rgb(65, 65, 65);
}

.other:hover {
  outline: 3px solid rgb(44, 139, 255);
}

.ui-menu-panel-title {
  color: white;
  text-align: center;
  font-size: 19px;
  padding-bottom: 5px;
  margin-bottom: 15px;
  border-bottom: 1px solid gray;
}

#ui-menu-content label {
  position: relative;
  width: 300px;
  font-size: 16px;
  color: white;
}

/* SELECTOR */
.selector-content {
  width: 100%;
  height: 42px;
  margin-top: 3px;
  margin-bottom: 15px;
  background: rgb(43, 43, 43);
}

.selector-button-left, .selector-text, .selector-button-right {
  float: left;
  height: 38px;
  line-height: 38px;
  color: white;
}

.selector-button-left, .selector-button-right {
  width: 38px;
  cursor: pointer;
  border: 2px solid transparent;
  transition: .15s;
  background: rgb(53, 53, 53);
}

.selector-button-left:hover, .selector-button-right:hover {
  border: 2px solid rgb(44, 139, 255);
}

.fa-angle-left, .fa-angle-right {
  width: 100%;
  font-size: 21px;
  text-align: center;
}

.selector-text {
  width: 216px;
  font-size: 18px;
  transition: .3s;
  text-align: center;
}

/* TIMER */
#ui-timer {
  position: absolute;
  display: none;
  z-index: 999;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -252px);
  color: rgb(163, 163, 163);
  letter-spacing: 1px;
}

#ui-text-timer {
  padding-left: 2px;
}

/* MESSAGES */
.message {
  position: relative;
  bottom: -30px;
  width: 100%;
  height: 30px;
  text-align: center;
  font-weight: 700;
  letter-spacing: 1px;
  color: rgba(212, 20, 20, .9);
}

/* KEYBOARD HELPER */
#keyboard-help {
  position: absolute;
  top: 50%;
  left: 50%;
  width: 880px;
  transform: translate(-50%, 310px);
}

#keyboard-help-left, #keyboard-help-right {
  display: inline;
  padding: 5px 10px;
  color: white;
  font-size: 17px;
  background: rgba(8, 8, 8, 0.35);
}

#keyboard-help-left {
  border-left: 3px solid rgba(0, 153, 255, 0.7);
}

#keyboard-help-right {
  float: right;
  border-right: 3px solid rgba(0, 153, 255, 0.7);
}

#ui-countdown {
  display: none;
  position: absolute;
  top: 50%;
  left: 50%;
  width: 880px;
  transform: translate(-50%, -50%);
}

#ui-text-countdown {
  color: white;
  text-align: center;
  font-size: 10em;
  animation-name: countdown-anim;
  animation-duration: 1s;
  animation-iteration-count: infinite;
}

@keyframes countdown-anim {
  from {
    transform: scale(1);
    opacity: 1;
  }

  to {
    transform: scale(1.3);
    opacity: 0;
  }
}

.hide-panel {
  opacity: 0;
  pointer-events: none;
  height: 0;
}

::-webkit-scrollbar {
  width: 7px;
}

/* Track */
::-webkit-scrollbar-track {
  border-radius: 3px;
  background: rgba(68, 68, 68, 0.5);
}

/* Handle */
::-webkit-scrollbar-thumb {
  border-radius: 3px;
  background: #888;
}

/* Handle on hover */
::-webkit-scrollbar-thumb:hover {
  background: #555;
}

#updateList-scroll, #historyMatch-scroll {
  width: 500px;
  height: 342px;
  overflow: auto;
  overflow-x: hidden;
  scrollbar-color: #888 rgba(68, 68, 68, 0.5);
  /* For Firefox */
  scrollbar-width: thin;
  /* For Firefox */
}


.update-block {
  width: calc(100% - 44px);
  margin: 10px 10px 15px 10px;
  padding: 10px;
  color: rgb(240, 239, 239);
  border: 2px solid rgb(90, 90, 90);
  background: rgb(51, 51, 51);
}

.update-block-title {
  font-weight: bold;
  color: white;
  border-bottom: 1px solid rgb(179, 179, 179);
  margin-bottom: 7px;
}

#historyMatch-scroll-content{
  display: flex;
  align-items: center;
  flex-direction: column-reverse;
}

.history-block {
  width: calc(100% - 40px);
  margin: 0 10px 10px 10px;
  padding: 10px;
  border: 2px solid rgb(133, 133, 133);
  background: rgb(47, 47, 47);
}

.history-title{
  color: white;
  text-shadow: 2px 0px 5px black;
  font-weight: bold;
  letter-spacing: 1px;
  border-bottom: 2px solid rgb(133, 133, 133);
  margin-bottom: 10px;
}

.history-text{
  color: rgb(255, 255, 255);
  font-weight: 500;
}