* {
     box-sizing: border-box;
}
 body {
     font-family: Arial, sans-serif;
     padding: 20px;
}
 #markdown-input {
     width: 100%;
     height: 100px;
}
 #html-output, #preview {
     height: 100px;
     display: inline-block;
     width: 100%;
     border: 1px solid #ccc;
     padding: 10px;
     margin: auto;
     white-space: pre-wrap;
     background-color: #f9f9f9;
}
 @media (min-width: 600px) {
     #markdown-input, #html-output, #preview {
         height: 200px;
         margin: 0;
    }
     #container {
         display: flex;
         justify-content: space-evenly;
         gap: 10px;
    }
}