styles.css

.screenwidth {
  max-width: 640px;
  margin: auto;
}

.lw { font-size: 60px; }
 /* The switch - the box around the slider */
.switch {
  position: relative;
  display: inline-block;
  width: 60px;
  height: 34px;
}

.width {
  margin-left: auto;
  margin-right: auto;
}

/* Hide default HTML checkbox */
.switch input {display:none;}

/* The slider */
.slider {
  position: absolute;
  cursor: pointer;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background-color: Silver;/*#008000; /* sets color of switch slider background when in "OFF" position */
  -webkit-transition: .4s;
  transition: .4s;
}

.slider:before {
  position: absolute;
  content: "";
  height: 26px;
  width: 26px;
  left: 4px;
  bottom: 4px;
  background-color: black;   /* sets color of slider button */
  -webkit-transition: .4s;
  transition: .4s;
}

input:checked + .slider {
  background-color: #008000;/*#008000; sets colour of switch slider background when in "ON" position */
}

input:focus + .slider {
  box-shadow: 0 0 1px #2196F3;
}

input:checked + .slider:before {
  -webkit-transform: translateX(26px);
  -ms-transform: translateX(26px);
  transform: translateX(26px);
}

/* Rounded sliders */
.slider.round {
  border-radius: 34px;
}

.slider.round:before {
  border-radius: 50%;
} 

/* "OFF" and "ON" text */
.offtext {
  font-size: 140%; 
  vertical-align: top;
  color: black;
}

.ontext {
  font-size: 140%; 
  vertical-align: top;
  color: black;
}


/* "temp" format */
.tempformat {
  font-size: 200%; 
  vertical-align: top;
}

/* Name of Zone text */
.nametext {
  font-size: 200%;
  margin-left: auto;
  margin-right: auto;
  text-align: center;
}
/* some control over the line holding the thermometer / Name of Zone and Temperature */
.topline {
  position: relative;
  display: inline-block;
}