<form id="form-adiciona">

​

        <div class="">

            <label for="mes-form">Mês:</label>

            <input id="mes-form" name="mes-form" type="text"  class="campo" ></br></br>

​

            <label for="data">Data:</label>

            <input id="data" name="data" type="text" class="campo" maxlength="10" placeholder="DD/MM/YYYY" required pattern="\d{2}\/\d{2}\/\d{4}">

​

​

            <label for="conta">Conta:</label>

            <input id="conta" name="conta" type="text"  class="campo-medio" required>

​

​

            <label for="valor">Valor:</label>

            <input id="valor" name="valor" type="text" class="campo" required value="0" maxlength="8">

        </div>

        </br>

        <button id="adiciona-conta">Adicionar</button>

​

    </form>