php session form post op 1 page

 <div class="container">
      <h1>Multi-step form</h1>
      <div class="form">
        <div class="inner">
          <ul class="steps">
            <li class="listItem show">
              <div class="col1">
                <span class="step"
                  ><span>1</span><span class="checkmark"></span
                ></span>
                <span class="line"></span>
              </div>
              <div class="col2 stepBody">
                <div class="stepTitle">
                  Step 1
                </div>
                <div class="content">
                  <div class="inputGroup">
                    <label for="name">How should we call you?</label>
                    <input
                      autocomplete="off"
                      type="text"
                      name="name"
                      id="name"
                    />
                  </div>
                  <div class="buttons">
                    <button class="next" disabled>Continue</button>
                  </div>
                </div>
              </div>
            </li>
            <li class="listItem">
              <div class="col1">
                <span class="step"
                  ><span>2</span><span class="checkmark"></span
                ></span>
                <span class="line"></span>
              </div>
              <div class="col2 stepBody">
                <div class="stepTitle">
                  Step 2
                </div>
                <div class="content">
                  <!-- wrap inputs into div to enable :focus-within css selector on container -->
                  <div class="inputGroup">
                    <label for="email">Your email</label>
                    <input
                      autocomplete="off"
                      type="email"
                      name="email"
                      id="email"
                    />
                  </div>
                  <div class="inputGroup">
                    <label for="password">Set password</label>
                    <input
                      autocomplete="off"
                      type="password"
                      name="password"
                      id="password"
                    />
                  </div>
                  <div class="buttons">
                    <button class="next" disabled>Continue</button>
                    <button class="prev">Back</button>
                  </div>
                </div>
              </div>
            </li>
            <li class="listItem">
              <div class="col1">
                <span class="step"
                  ><span>3</span><span class="checkmark"></span
                ></span>
                <span class="line"></span>
              </div>
              <div class="col2 stepBody">
                <div class="stepTitle">
                  Step 3
                </div>
                <div class="content">
                  <div class="inputGroup">
                    <p>
                      Congratulations! Now you're all set,<br />
                      hit that submit button!
                    </p>
                  </div>
                  <div class="buttons">
                    <button class="submit">Submit</button>
                    <button class="prev">Back</button>
                  </div>
                  <div class="message">
                    <span class="success">You signed up succesfully!</span>
                    <span class="fail"
                      >Oops, something went wrong! Please double-check your
                      inputs.</span
                    >
                  </div>
                </div>
              </div>
            </li>
          </ul>
        </div>
      </div>
    </div>

    <script type="module" src="js/main.js"></script>
  </body>