JSFiddle - React, Tailwind, and code Playground

HTML

<div class="wrapper">
    <ol>
        <li>
            <div class="input-item">
                <label for="item1">Item 1</label>
                <input type="text" id="item1" name="item1">
                <div class="error"></div>
            </div>
        </li>

        <li>
            <div class="input-item">
                <label for="item2">Item 2</label>
                <input type="text" id="item2" name="item2">
                <div class="error"></div>
            </div>
        </li>

        <li>
            <div class="input-item">
                <label for="item3">Item 3</label>
                <input type="text" id="item3" name="item3">
                <div class="error"></div>
            </div>
        </li>

        <li>
            <div class="input-item">
                <label for="item4">Item 4</label>
                <input type="text" id="item4" name="item4">
                <div class="error"></div>
            </div>
        </li>

        <li>
            <div class="input-item">
                <label for="item5">Item 5</label>
                <input type="text" id="item5" name="item5">
                <div class="error"></div>
            </div>
        </li>

        <li>
            <div class="input-item">
                <label for="item6">Item 6</label>
                <input type="text" id="item6" name="item6">
                <div class="error"></div>
            </div>
        </li>

        <li>
            <div class="input-item">
                <label for="item7">Item 7</label>
                <input type="text" id="item7" name="item7">
                <div class="error"></div>
            </div>
        </li>

        <li>
            <div class="input-item">
                <label for="item8">Item 8</label>
                <input type="text" id="item8" name="item8">
                <div class="error"></div>
            </div>
        </li>
    </ol>

    <br />

    <button id="button" onclick={validateForm()}>
      ...

CSS

ol {
    background-color: lightblue;
    list-style-type: none;
    padding: 0;
    margin: 0;
    display: flex;
    flex-direction: column;
    flex-wrap: wrap;
    max-height: 100px;
}

@media (max-width: 500px) {
    ol {
        display: block;
        max-height: none;
    }
}

ol li {
    flex: 1 auto;
}

.error {
    color: firebrick;
}

JavaScript

const submitButton = document.getElementById("button");
submitButton.onclick = validateForm;

/* Checks to see if the form inputs are empty. If so, display error message */
function validateForm() {
    const inputItems = document.getElementsByClassName('input-item')
    
    for (const item of inputItems) {
    	const input = item.children[1]
        if (input.value === '') {
        	item.children[2].innerHTML = 'Enter an input'
        }
    }
}