body {
  font-size: 16px;
  margin: 0;
  
    padding-top: 10px;
  padding-right: 5px;
  padding-bottom: 10px;
  padding-left: 5px;
}

div {
  display: flex;
  flex-wrap: nowrap;
  flex-direction: row;
  justify-content: center;
  align-items: stretch;
  align-content: space-between
    flex-basis: auto;
    flex-shrink: 1;
    flex-grow: 1;
  flex: 1 0 auto;
  margin: 10px;
}

.row {
    flex-flow: row;
    justify-content: row;
    flex-direction: row;
}

.col {
    flex-flow: column;
    justify-content: center;
    flex-direction: column;
}

.spacer {
    flex-grow: 1;
}

.ranges {
  min-height: 69vh;  
}

label {
  display: block;
  margin-bottom: 5px;
}

input[type="range"] {
  display: block;
  height: 100%;
  -webkit-appearance: none;
  margin: 10px 0;
  appearance: slider-vertical;
  accent-color: red;
}

input[type="range"]:focus {
  outline: none;
}

input[type="range"]::-webkit-slider-runnable-track {
  width: 100%;
  height: 100%;
  background: #ccc;
  border-radius: 5px;
  border: none;
}

input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 100%;
  height: 30px;
  background: #fff;
  border-radius: 50%;
  border: 2px solid #ccc;
  margin-top: -12px;
  min-width: 100%;
}

input[type="range"]:focus::-webkit-slider-runnable-track {
  width: 100%;
  background: #ddd;
}

input[type="range"]::-webkit-slider-thumb:active {
  background: #ccc;
  width: 100%;

}

button {
  display: block;
  width: 100%;
  height: 50px;
  font-size: 20px;
  background: #ccc;
  border: none;
  border-radius: 5px;
  margin-top: 10px;
}

button:focus {
  outline: none;
}

#currentFreq {
  font-size: 20px;
  font-weight: bold;
  margin-top: 10px;
}