#title {
    font-family:'Times New Roman', Times, serif;
    font-size: 1.5cm;
    color: white;
}

#header {
    position: relative;
    text-align: center;
    padding: 10px 0;
}

.buttons {
    width: 650px;
    height: 325px;
    color: black;
    text-align: center;
    cursor: pointer;
    background-color: darkgrey;
    font-size: 80px;
    transition-duration: 0.4s;
    margin: 4px 2px;
    display: inline-block;
    padding: 16px 32px;
    border: none;
    border-radius: 64px;
}

#button1 {

    border: none;
    float: left;
    border: 2px solid blue;
}

#button1:hover {
    background-color: blue;
    color: white;
    border-radius: 30px;
}

#button2 {
    border: none;
    float: right;
    border: 2px solid green;
}

#button2:hover {
    background-color: green;
    color: white;
    border-radius: 30px;
}

#button3 {
    border: none;
    position: absolute; 
    top: 70%; 
    left: 50%; 
    transform: translate(-50%, -50%);
    border: 2px solid red;
}

#button3:hover {
    background-color: red;
    color: white;
    border-radius: 30px;
}

#button4 {
    position: absolute;
    left: 0;
    top: 50%;
    transform: translateY(-50%);
    border: none;
    background-color: darkgray;
    font-size: 25px;
    cursor: pointer;
    border: 2px solid white;
    transition-duration: 0.4s;
    border-radius: 8px;
    padding: 5px 10px;
}


#button4:hover {
    background-color: white;
    border-radius: 12px;
}

#image_inline {
    height: 7cm;
    width: auto;
    position: absolute;
    left: 2%;
    top: 40%;
}

#preview {
    width: 50%;
    height: 700px;
    position: absolute;
    right: 2%;
    top: 20%;
}

#preview_external {
    width: 50%;
    height: 1150px;
    position: absolute;
    right: 2%;
    top: 20%;
}

#image_internal {
    height: 12cm;
    width: auto;
    position: absolute;
    left: 2%;
    top: 33%;
}
#image_external_html {
    height: 12cm;
    width: auto;
    position: absolute;
    left: 2%;
    top: 18%;
}
#image_external_css {
    height: 20cm;
    width: auto;
    position: absolute;
    left: 2%;
    top: 65%;
}

body {
    background-color: darkgray;
    margin-left:1cm;
    margin-right: 1cm;
    margin-bottom: 5cm;
}