<form class="form-group">
    <h2>Sign in</h2>
    <label>
        <span class="input-label">
            Username
        </span>
        <input required type="text" />
    </label>

    <label>
        <span class="input-label">
            Email
        </span>
        <input required type="email" />
    </label>

    <label>
        <span class="input-label">
            Password
        </span>
        <input required minlength="5" type="password" placeholder="Password" class="input-error" />
    </label>
    <span class="validation-error">Password should be minimum 5 character.</span>
    <button class="btn btn-primary">Sign In</button>
</form>