body {
  background-color: #121212;
  color: white;
}

h1 {
  margin-bottom: 20px;
  text-align: center;
}

.btn {
  box-shadow: 0px 5px 10px #222222;
}

.btn:focus {
  outline: none;
}

.button-row div {
  width: 60px;
  height: 60px;
  text-align: center;
  line-height: 60px;
  margin: 5px;
}

.button-row .btn {
  width: 60px;
  height: 60px;
  background-color: #636363;
}

.button-row .btn:hover {
  background-color: #858585;
  color: white !important;
}

.button-orange {
  background-color: #FF8400 !important;
}

.button-orange:hover {
  background-color: #FFA647 !important;
}

.button-blue {
  background-color: #0099FF !important;
}

.button-blue:hover {
  background-color: #33ADFF !important;
}

.button-off {
  background-color: #454545 !important;
}

.calc-history-eq {
  color: #B0B0B0;
  cursor: pointer;
}

#container {
  width: 600px;
  background-color: #2E2E2E;
  height: 100%;
  border-radius: 10px;
  margin-top: 60px;
}

#expression {
  height: 60px;
  margin-bottom: 20px;
  padding: 10px;
  text-align: right;
  background-color: #636363;
  border-radius: 5px;
  font-size: 30px;
  box-shadow: 0px 5px 10px #444444 inset;
}

#standard-buttons {
  display: inline-block;
  margin-left: -20px;
  margin-bottom: 10px;
}

#advanced-buttons {
  display: inline-block;
  display: none;
  margin-left: -20px;
}

#toggle-advanced:hover {
  background-color: #858585 !important;
}

#toggle-advanced span {
  pointer-events: none;
}

#calc-history {
  float: right;
  width: 200px;
  height: 270px;
  background-color: #636363;
  border-radius: 5px;
  margin-top: 6px;
  padding: 10px;
  box-shadow: 0px 5px 10px #444444 inset;
}

#calc-history-box {
  width: 180px !important;
  height: 220px !important;
  resize: none;
  overflow: hidden;
}

#calc-history hr {
  margin-top: 5px;
  margin-bottom: 5px;
}

#footer {
  background-color: #262626;
  margin-left: -15px;
  margin-right: -15px;
  margin-bottom: -15px;
  margin-top: 15px;
  padding: 10px;
  padding-bottom: 1px;
  color: #636363;
  border-bottom-left-radius: 10px;
  border-bottom-right-radius: 10px;
}

.article {
  padding: 50px 20% 1%;
}