/* Reset */
html, body, #mainView {
  width: 100%; height: 100%; margin: 0; padding: 0;
}
/* Custom behaviors */
html * {
  -webkit-user-select: none; box-sizing: border-box;
}
/* mainView container */
#mainView {
  display: flex; border-top: 1px solid #c7c7c7;
}
/* Right sidebar */
#sidebar {
  flex: 0 0 100px;
  padding: 15px 0; text-align: center;
  background: #414A4C; color: #f8f8f8;
}
/* Todo container */
#todoListContainer {
  flex: 1;
  background: #F8F8FF; overflow: auto;
}
/* Button styling */
.button {
  font-family: sans-serif; font-weight: 800;
  display: inline-block; border-radius: 100%;
  color: #F8F8FF; text-align: center; text-decoration: none;
  transition: background-color 0.2s linear;
}
/* Add button */
.add-button {
  background...