styles.css

@font-face {
  font-family: "logo";
  src: url("fonts/logo-font.ttf");
}
@font-face {
  font-family: "Clear Sans";
  src: url("fonts/ClearSans-Regular.ttf");
}
*,
html,
body {
  margin: 0;
  padding: 0;
}
html,
body {
  height: 100%;
  overflow: hidden;
  font-family: "Clear Sans";
  color: white;
}
ul {
  text-decoration: none;
  flex-direction: column;
  list-style: none;
  background: #485054;
  padding-left: 10px;
}
.content,
.sidebar,
.canvas,
.logo,
ul,
.slidecontainer,
#saveButton {
  display: flex;
  flex-shrink: 0;
}
.content {
  flex-direction: row;
  height: 100%;
}
.content .sidebar {
  flex-basis: 18em;
  overflow-x: hidden;
  overflow-y: auto;
  flex-direction: column;
  background: #485054;
}
.content .sidebar input[type=radio]:focus {
  outline: none;
}
.content .sidebar input[type=radio]:checked {
  color: white !important;
  border-left: 5px solid #485054;
  border-bottom: 1px solid rgba(255, 255, 255, 0.5);
}
.content .sidebar input[type=radio] {
  width: 100%;
  height: 100%;
  -webkit-appearance: none;
  user-select: none;
  color: rgba(255, 255, 255, 0.7);
  font-size: 20px;
  cursor: pointer;
  transition: color 1s ease;
}
.content .sidebar input[type=radio]:hover {
  color: white;
  border-left: 5px solid #485054;
}
.content .sidebar .ray:before {
  content: "Луч";
}
.content .sidebar .beam:before {
  content: "Пучок";
}
.content .sidebar .point_source:before {
  content: "Точечный источник";
}
.content .sidebar .flat_mirror:before {
  content: "Плоское зеркало";
}
.content .sidebar .coll_lens:before {
  content: "Собирающая линза";
}
.content .sidebar .diff_lens:before {
  content: "Рассеивающая линза";
}
.content .sidebar .obstacle:before {
  content: "Препятствие";
}
.content .sidebar #coll_lens,
.content .sidebar #diff_lens {
  display: none;
}
.content .sidebar h3 {
  user-select: none;
  margin-top: 10px;
  margin-bottom: 10px;
  padding-left: 10px;
  font-size: 24px;
  color: white;
  cursor: default;
  border-bottom: 1px solid rgba(255, 255, 255, 0.5);
}
.content .sidebar li {
  user-select: none;
  color: rgba(255, 255, 255, 0.7);
  font-size: 20px;
  cursor: pointer;
  padding: 7px;
  transition: color 0.5s ease;
}
.content .sidebar .logo {
  justify-content: center;
  transition: all 0.5s ease;
  cursor: default;
  border-bottom: 1px solid rgba(255, 255, 255, 0.9);
  margin-bottom: 20px;
}
.content .sidebar .logo p {
  user-select: none;
  display: flex;
  font-family: "logo";
  color: rgba(255, 255, 255, 0.9);
  font-size: 50px;
}
.content .sidebar .logo:hover {
  background: rgba(0, 0, 255, 0.5);
  color: white;
}
.content .canvas {
  flex-basis: 100%;
}
.content .canvas #layer1,
.content .canvas layer2 {
  position: absolute;
  width: calc(100% + 1px);
  height: calc(100% + 1px);
}
.content .slidecontainer {
  padding-left: 10px;
  padding-top: 10px;
  width: 100%;
}
.content .slidecontainer #density_slider,
.content .slidecontainer #brightness_slider {
  width: 80%;
  outline: none;
  opacity: 0.7;
  transition: opacity 0.2s;
}
.content .slidecontainer #density_slider:hover,
.content .slidecontainer #brightness_slider:hover {
  opacity: 1;
}
.content .slidecontainer #density_value,
.content .slidecontainer #brightness_value {
  padding: 0 0 2px 5px;
}
.content #saveButton {
  margin: auto;
  width: 80%;
  justify-content: center;
  color: white;
  background: indigo;
  font-size: 25px;
  font-weight: bold;
  margin-top: 35px;
  border-radius: 100px;
  cursor: pointer;
  transition: 0.4s;
}
.content #saveButton:hover {
  background: black;
}