JSFiddle - React, Tailwind, and code Playground

HTML

<form>
<h2>
Personal Details
</h2>
<fieldset>
<legend>
Personal Details
</legend>
<label for="name">Your name<br>
<input type="text" name="name" id="name" placeholder="Write your full name"></label>
<label for="email">Your email<br>
<input type="email" name="email" id="email" placeholder="Enter your email"></label>
<label for="phone">Your phone number<br>
<input type="text" name="phone" id="phone" placeholder="Enter your phonenumber"></label>
<label for="need">Select what you need<br>
<select name="need" id="need">
<option>1</option>
<option>2</option>
</select></label>
</fieldset>
<fieldset>
<legend>
More info
</legend>
<label for="type">Type<br>
<select name="type" id="type">
<option>Type</option>
</select></label>
<label for="quantity">Quantity<br>
<select name="quantity" id="quantity">
<option>Quantity</option>
</select></label>
<label for="size">Size<br>
<select name="size" id="size">
<option>Size</option>
</select></label>
</fieldset>
</form>

CSS

* {
  margin: 0;
  padding: 0;
}
h2 {
  text-align: center;
}
fieldset, legend {
  border: none;
}
legend {
  display: none;
}
fieldset {
  display: flex;
  flex-wrap: wrap;
  width: 50em;
  margin: 0 auto;
}
fieldset + fieldset {
  width: 40.5em;
}
fieldset label {
  width: 50%;
flex: 1 0 50%;
  text-align: center;
}
fieldset + fieldset label {
  width: 33%;
  flex: 1 0 33%;
}
input,select {
  background: black;
  color: white;
  padding: 1em;
  border: none;
  border-radius: .2em;
  min-width: 20em;
  margin-bottom: 1em;
}
fieldset + fieldset select {
  min-width: 19em;
}