html, body {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  width: 100%;
  height: 100%;
}
*, *::before, *::after {
  box-sizing: inherit;
}

/* Equivalent of @include center for body */
body {
  display: block;
  background: #000; /* optional */
}

/* Container Styles */
.container {
  position: relative;
  width: 900px;
  height: 600px;
  border: 2px solid white;
}

/* Image Layer Styles */
.container .img {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background-size: 900px 100%;
}

.container .background-img {
  background-image: url('../img/Free_Standing_LED_Screen_-_East_Street_-_NO_SCREEN.jpg');
}

.container .foreground-img {
  background-image: url('../img/Free_Standing_LED_Screen_-_East_Street.jpg');
  width: 50%;
}

/* Slider Styles */
.container .slider {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: transparent;
  margin: 0;
  appearance: none;
  z-index: 10;
  pointer-events: all;
}

.container .slider:hover {
  background: rgba(242, 242, 242, 0.1);
}

/* Slider Thumbs */
.container .slider::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 6px;
  height: 600px;
  background: white;
  cursor: pointer;
}

.container .slider::-moz-range-thumb {
  width: 6px;
  height: 600px;
  background: white;
  cursor: pointer;
}

/* Thin vertical slider bar (the thumb track) */
.container .slider::-webkit-slider-runnable-track {
  width: 100%;
  height: 100%;
  background: transparent;
  border: none;
}

.container .slider::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 6px;
  height: 100%;
  background: white;
  cursor: pointer;
  margin-top: 0; /* removes offset */
}

.container .slider::-moz-range-thumb {
  width: 6px;
  height: 100%;
  background: white;
  cursor: pointer;
}

/* Optional: remove default styling in Firefox */
.container .slider::-moz-range-track {
  background: transparent;
  border: none;
}

/* Slider Button */
.container .slider-button {
  pointer-events: none;
  position: absolute;
  width: 30px;
  height: 30px;
  border-radius: 50%;
  background-color: white;
  left: calc(50% - 18px);
  top: calc(50% - 18px);
  display: flex;
  justify-content: center;
  align-items: center;
}

/* Arrow-style Button: Before and After Arrows */
.container .slider-button::after,
.container .slider-button::before {
  content: '';
  padding: 3px;
  display: inline-block;
  border: solid #5D5D5D;
  border-width: 0 2px 2px 0;
}

.container .slider-button::after {
  transform: rotate(-45deg);
}

.container .slider-button::before {
  transform: rotate(135deg);
}