JSFiddle - React, Tailwind, and code Playground

HTML

<form action="index.php" class="form-1" method="POST">
            <div class="form-contents"> 
                <div class="form-fields"> 
                    <ul>
                        <li class="fline">
                            <label for="cell">Номер телефона</label>
                            <div class="finput">
                                <input type="text" id="cell" name="cellphone" value="+375(хх)ххх-хх-хх">
                            </div>
                        </li>
                        <li class="fline">
                            <label for="email">Почта</label>    
                            <div class="finput">
                                <input type="text" id="email" name="email" value="">
                            </div>
                        </li>
                        <li class="fline">
                            <label for="surname">Фамилия</label>
                            <div class="finput">
                                <input type="text" id="surname" name="surname" value="">
                            </div>
                        </li>
                        <li class="fline">
                            <label for="name">Имя</label>
                            <div class="finput">
                                <input type="text" id="name" name="name" value="">
                            </div>
                        </li>
                        <li class="fline">
                            <label for="secondname">Отчество</label>
                            <div class="finput">
                                <input type="text" id="secondname" name="secondname" value="">
                            </div>
                        </li>
                        <li class="fline">
                            <label for="birthdate">Дата рождения</label>
                            <div class="finput">
                                <input type="text" id="birthdate" name="birthdate"...

CSS

.form-1 {
    background-color: azure;
}

.form-contents {
    width: 40%;
    margin: auto;
    background-color: activecaption;
}

.form-fields {
    text-align: right;
    width: 80%;
    margin: auto;
    background-color: antiquewhite;
}

.fline {
    display: block;
    margin-left:auto;
    margin-right: auto;
    border: 1px white solid;
}

.fline label {
    display: inline-block;
    margin: 5px;
}

.finput {
    display: inline-block;
    margin: 5px;
}

.fbuttons {
    text-align: center;
    width: 80%;
    margin: auto;
    background-color: antiquewhite;
}
.fbuttons input {
    width: 80px;
    height: 30px;
    margin: 5px;
}