contact.html

<form method="post" action="contact.php">
  <div class="form-floating mb-3 mt-3">
    <input
      type="text"
      id="Name"
      name="Name"
      class="form-control"
      placeholder="Name:"
    />
    <label for="Name" class="form-label">Name:</label>
  </div>

  <div class="form-floating mb-3 mt-3">
    <input
      type="text"
      id="Email"
      name="Email"
      class="form-control"
      placeholder="E-Mail:"
    />
    <label for="Email" class="form-label">E-Mail:</label>
  </div>

  <div class="form-floating mb-3 mt-3">
    <input
      type="text"
      id="Betreff"
      name="Betreff"
      class="form-control"
      placeholder="Betreff"
    />
    <label for="Betreff" class="form-label">Betreff:</label>
  </div>

  <div class="form-floating mb-3 mt-3">
    <textarea
      id="Nachricht"
      name="Nachricht"
      class="form-control"
      placeholder="Nachricht:"
    ></textarea>
    <label for="Nachricht" class="form-label">Nachricht:</label><br />
  </div>

  <input type="submit" name="submit" class="button" />
</form>