Tilføj required-attributten på input-felterne i HTML og brug pseudo-klasserne til at style gyldige/ugyldige felter. Lav regler for:
<form>
<div class="form-group">
<label for="first_name">First name</label>
<input type="text" id="first_name" name="first_name" />
<p class="error-message">Please enter a value</p>
</div>
<div class="form-group">
<label for="last_name">Last name</label>
<input type="text" id="last_name" name="last_name" />
<p class="error-message">Please enter a value</p>
</div>
<div class="form-group">
<label for="email">Email</label>
<input type="email" id="email" name="email" />
<p class="error-message">Please enter a value</p>
</div>
<div class="form-group">
<label for="password">Password</label>
<input type="password" id="password" name="password" minlength="8" />
<p class="error-message">Please enter a value</p>
</div>
<div class="form-group">
<label for="terms">
<input type="checkbox" id="terms" name="accept_terms" value="yes" />
Accept terms
</label>
<p class="error-message">Please tick the box</p>
</div>
<button>Sign up</button>
</form>
Hints
<form>
<div class="form-group">
<!-- ... -->
<input name="first_name" ... required />
<!-- ... -->
</div>
<div class="form-group">
<!-- ... -->
<input name="email" ... required />
<!-- ... -->
</div>
<!-- ... -->
</form>