style.css

body    {
    display: flex;
    flex-direction: column;
    align-items: center;
    margin: 0px;
    font-family: 'Courier New', Courier, monospace;
    color: #F9D342;;
    background-color: #292826;
}

#container {
    background-color: white;
    padding: 2%;
}

h1, h2 {
    margin: 1%;
}

p {
    margin: 0;
    margin: 0 15% 0 15%;
}

.buttons {
    margin: 2%;
}

button {
    padding: 0.2rem 2rem 0.2rem 2rem;
    font-family: 'Proxima N W01 Bold', Arial, sans-serif;
    color: #292826;
    border: none;
    border: 0.1rem #F9D342 solid;
}

button:hover{
    transform: scale(1.08);
}

.rainbowPen {
    background-color: #cdedfd;
    background-image: linear-gradient(319deg, #cdedfd 0%, #ffec82 37%, #ffcfd2 100%);
}

.blackPen {
    background-color: black;
    color: #F9D342;
}

#eraser , #clear {
    background-color: #F9D342;
    color: #292826;
}

#clear {
    background-color: white;
}

#gridSize {
    margin: 2%;
}

.slider{
    margin-bottom: 2%;
}

input[type="range"] {
    -webkit-appearance: none;
    

    width: 200px;
    height: 7px;
    border-radius: 5px;
    background-image: linear-gradient(#F9D342, #F9D342);
    background-repeat: no-repeat;
  }

  input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    height: 20px;
    width: 20px;
    border-radius: 50%;
    background: #F9D342;
    cursor: ew-resize;
    box-shadow: 0 0 2px 0 #555;
    transition: background .3s ease-in-out;
  }

  .octocat {
    width: 2rem;
    height: 2rem;
}

.link {
    color: #F9D342;
    text-decoration: underline;
}