style.css

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  outline: none;
  -webkit-tap-highlight-color: transparent;
  font-family: Sans-Serif;
}

body {
  display: flex;
  flex-direction: column;
  justify-content: space-evenly;
  align-items: center;
}

header {
  height: 20vh;
  width: 100%;
  background: #000;
  display: flex;
  justify-content: space-between;
  align-items: center;
  color: #fff;
  padding: 5%;
  position: sticky;
  top: 0;
}

nav {
  display: flex;
  justify-content: space-evenly;
  align-items: center;
  width: 30%;
}



.btn {
  border: 1px solid white;
  background: black;
  color: #fff;
  padding: 3% 5%;
  margin: 1%;
  transition: filter 0.2s ease;
}

.btn:hover {
  filter: invert(1);
}

.btn:active {
  transform: scale(0.9);
}

canvas {
  border: 1px solid black;
  box-shadow: 0px 0px 15px rgba(0, 0, 0, 0.25);
  margin: 5%;
}

.error-container {
  width: 100%;
}

.error {
  background: red;
  color: #fff;
  padding: 1%;
}