html-css-javascript-online-editor-compiler

@import url(https://fonts.googleapis.com/css?family=Open+Sans);
body{
    background-color: #000;
    text-align: center;
    min-height: 270px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-family: "Open Sans";
}

.btn-border {
  width: 170px;
  padding: 10px 0;
  text-align: center;
  cursor: pointer;
  background: #fff;
  position: relative;
}

.btn-border p {
  color: #111;
  font-weight: 600;
  font-size: 16px;
}

.b-tb:before {
  content: "";
  position: absolute;
  width: 50px;
  height: 3px;
  top: -6px;
  left: -7px;
  background: #fff;
  transition: all 0.5s ease;
}

.b-tb:after {
  content: "";
  position: absolute;
  width: 50px;
  height: 3px;
  bottom: -6px;
  right: -7px;
  background: #fff;
  transition: all 0.5s ease;
}

.b-lr:before {
  content: "";
  position: absolute;
  top: -4px;
  left: -7px;
  width: 3px;
  height: 25px;
  background: #fff;
  transition: all 0.5s ease;
}

.b-lr:after {
  content: "";
  position: absolute;
  bottom: -4px;
  right: -7px;
  width: 3px;
  height: 25px;
  background: #fff;
  transition: all 0.5s ease;
}

.btn-border:hover .b-tb:before,
.btn-border:hover .b-tb:after {
  width: calc(100% + 14px);
  transition: all 0.5s ease;
}

.btn-border:hover .b-lr:before,
.btn-border:hover .b-lr:after {
  height: calc(100% + 7px);
  transition: all 0.5s ease;
}

Press Ctrl+Space Key for Auto complete and Intelli Sense