JSFiddle - React, Tailwind, and code Playground

HTML

<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/jquery-datetimepicker/2.5.9/jquery.datetimepicker.css" integrity="sha512-bYPO5jmStZ9WI2602V2zaivdAnbAhtfzmxnEGh9RwtlI00I9s8ulGe4oBa5XxiC6tCITJH/QG70jswBhbLkxPw==" crossorigin="anonymous" referrerpolicy="no-referrer" />
    <script src="https://code.jquery.com/jquery-3.7.1.js"integrity="sha256-eKhayi8LEQwp4NKxN+CfCh+3qOVUtJn3QNZ0TciWLP4=" crossorigin="anonymous"></script>
    <script src="https://cdnjs.cloudflare.com/ajax/libs/jquery-datetimepicker/2.5.9/jquery.datetimepicker.full.min.js" integrity="sha512-hDFt+089A+EmzZS6n/urree+gmentY36d9flHQ5ChfiRjEJJKFSsl1HqyEOS5qz7jjbMZ0JU4u/x1qe211534g==" crossorigin="anonymous" referrerpolicy="no-referrer"></script>
    
    
<form>

        <fieldset class="fieldset_frame">

                <legend>訂房日期</legend>
                <div><input id="datetimepicker_in" class="chinput in" type="text" placeholder="入住日期 --/--/--"></div>
                <div><input id="datetimepicker_out" class="chinput out" type="text" placeholder="退房日期 --/--/--"></div>
                <div><input class="btn" type="button" value="訂房"></div>

        </fieldset>
    
</form>

CSS

.fieldset_frame{
    width: 600px;
    height: 100px;

    display: flex;
    justify-content:space-evenly; 
    align-items: center;

    font-family: Comic Sans MS , Microsoft JhengHei;

    border: 2px dashed rgb(255, 131, 131);

    border-left: 3px solid rgb(122, 153, 255);

}

.fieldset_frame legend{
    font-size: 28px;
}

.chinput{

    width: 242px;
    height: 30px;

    font-family: Comic Sans MS , Microsoft JhengHei;
    box-sizing: border-box;
    text-indent: 5px;
}

.btn{
    width: 50px;
    height: 30px;
}

JavaScript

$.datetimepicker.setLocale('zh-TW');



$('#datetimepicker_in,#datetimepicker_out').datetimepicker({
    i18n: {
        de: {
            months: [
                'Januar', 'Februar', 'März', 'April',
                'Mai', 'Juni', 'Juli', 'August',
                'September', 'Oktober', 'November', 'Dezember',
            ],
            dayOfWeek: [
                "So.", "Mo", "Di", "Mi",
                "Do", "Fr", "Sa.",
            ]
        }
    },
    timepicker: false,
    format: 'Y/m/d'
});