<html>
    <head>
        <meta charset="utf-8">
        <meta name="viewport" content="width=device-width, initial-scale=1.0">
        <title>Sign Up Form</title>
    </head>
    <body>

      <form action="index.html" method="post">
        
        <h1>Sign Up</h1>
        
        <fieldset>
          
          <legend><span class="number">1</span> Your basic info</legend>
          
          <label for="name">Name:</label>
          <input type="text" id="name" name="user_name">
          
          <label for="mail">Email:</label>
          <input type="email" id="mail" name="user_email">
          
          <label for="password">Password:</label>
          <input type="password" id="password" name="user_password">
          
          <label>Age:</label>
          <input type="radio" id="under_13" value="under_13" name="user_age"><label for="under_13" class="light">Under 13</label><br>
          <input type="radio" id="over_13" value="over_13" name="user_age"><label for="over_13" class="light">13 or Older</label>
        
        </fieldset>
        
        <fieldset>
          
          <legend><span class="number">2</span> Your profile</legend>
          
          <label for="bio">Biography:</label>
          <textarea id="bio" name="user_bio"></textarea>
          
          <label for="job">Job role:</label>
          <select id="job" name="user_job">
            <optgroup label="Web">
              <option value="frontend_developer">Front-End Developer</option>
              <option value="php_developer">PHP Developer</option>
              <option value="python_developer">Python Developer</option>
              <option value="rails_developer">Rails Developer</option>
              <option value="web_designer">Web Designer</option>
              <option value="wordpress_developer">WordPress Developer</option>
            </optgroup>
            <optgroup label="Mobile">
              <option value="android_developer">Android Developer</option>
              <option value="ios_developer">iOS Developer</option>
              <option value="mobile_designer">Mobile Designer</option>
            </optgroup>
            <optgroup label="Business">
              <option value="business_owner">Business Owner</option>
              <option value="freelancer">Freelancer</option>
            </optgroup>
          </select>
        
          <label>Interests:</label>
          <input type="checkbox" id="development" value="interest_development" name="user_interest"><label class="light" for="development">Development</label><br>
          <input type="checkbox" id="design" value="interest_design" name="user_interest"><label class="light" for="design">Design</label><br>
          <input type="checkbox" id="business" value="interest_business" name="user_interest"><label class="light" for="business">Business</label>
          
        </fieldset>
          
        <button type="submit">Sign Up</button>
        
      </form>
      
    </body>
</html>
*, *:before, *:after {
  -moz-box-sizing: border-box;
  -webkit-box-sizing: border-box;
  box-sizing: border-box;
}

body {
  font-family: 'Nunito', sans-serif;
  color: #384047;
}

form {
  max-width: 300px;
  margin: 10px auto;
  padding: 10px 20px;
  background: #f4f7f8;
  border-radius: 8px;
}

h1 {
  margin: 0 0 30px 0;
  text-align: center;
}

input[type="text"],
input[type="password"],
input[type="date"],
input[type="datetime"],
input[type="email"],
input[type="number"],
input[type="search"],
input[type="tel"],
input[type="time"],
input[type="url"],
textarea,
select {
  background: rgba(255,255,255,0.1);
  border: none;
  font-size: 16px;
  height: auto;
  margin: 0;
  outline: 0;
  padding: 15px;
  width: 100%;
  background-color: #e8eeef;
  color: #8a97a0;
  box-shadow: 0 1px 0 rgba(0,0,0,0.03) inset;
  margin-bottom: 30px;
}

input[type="radio"],
input[type="checkbox"] {
  margin: 0 4px 8px 0;
}

select {
  padding: 6px;
  height: 32px;
  border-radius: 2px;
}

button {
  padding: 19px 39px 18px 39px;
  color: #FFF;
  background-color: #4bc970;
  font-size: 18px;
  text-align: center;
  font-style: normal;
  border-radius: 5px;
  width: 100%;
  border: 1px solid #3ac162;
  border-width: 1px 1px 3px;
  box-shadow: 0 -1px 0 rgba(255,255,255,0.1) inset;
  margin-bottom: 10px;
}

fieldset {
  margin-bottom: 30px;
  border: none;
}

legend {
  font-size: 1.4em;
  margin-bottom: 10px;
}

label {
  display: block;
  margin-bottom: 8px;
}

label.light {
  font-weight: 300;
  display: inline;
}

.number {
  background-color: #5fcf80;
  color: #fff;
  height: 30px;
  width: 30px;
  display: inline-block;
  font-size: 0.8em;
  margin-right: 4px;
  line-height: 30px;
  text-align: center;
  text-shadow: 0 1px 0 rgba(255,255,255,0.2);
  border-radius: 100%;
}

@media screen and (min-width: 480px) {

  form {
    max-width: 480px;
  }

}

External CSS

  1. https://cdnjs.cloudflare.com/ajax/libs/normalize/4.2.0/normalize.min.css
  2. https://fonts.googleapis.com/css?family=Nunito:400,300

External JavaScript

This Pen doesn't use any external JavaScript resources.