[Contact Form 7] Align the input fields properly

Hello !

I have a little tiny problem, I made a contact form and I want the input fields to be justified.
Here is the current look:

http://s28.postimg.org/ihnai5yel/Capture_d_e_cran_2015_12_11_a_13_13_19.png

How could I do that in CSS without having to manually set the size of the input fields (it won’t be justified anyway). I tried many things, I’ve looked for other threads/replies but none of them applies to my problem since I have 2 or more fields by line.

Here are my current codes:

.wpcf7-submit {
  margin-top: 0px;
  padding: 30px 180px !important;
  font-size: 22px !important;
  font-weight: bold !important;
  line-height: 1.3333333;
  border-radius: 6px;
  background-color: #0092d7 !important;
  color: #FFFFFF !important;
  border: 0px !important;
}

.wpcf7 select {
    background-color: #FFFFFF;
    border: 1px solid #ccc;
    border-radius: 0px !important;
    margin-right: 5px !important;
    width: 90px;
    height: 32px;

}

#tirage{
    font-family: 'Open Sans';
    background-image: url("img/bg_tirage.jpg");
    background-repeat: no-repeat;

}

#tirage-header{
    padding-left: 68px;
    padding-top: 45px;
    padding-bottom: 25px;
    width: 89%;
}

#tirage-form{
    font-family: 'Open Sans';
    padding-left: 20px;
    padding-bottom: 100px;
    font-weight: bolder;
}

in the CF7 style.css

And in the CF7 form :

<div id="tirage">
<div id="tirage-header">

<img src="../img/header.png">
</div>
<div id="tirage-form">
[select* intitule "M." "Mme"][text* nom size:35 placeholder "Votre nom"][text* prenom size:35 watermark "Votre prénom"]
Date de naissance : [date* date-de-naissance "JJ/MM/AAAA"][email* email watermark "Adresse mail"]
[text* adresse watermark "Adresse"]
[tel* code-postal maxlength:5 watermark "Code postal"][text* ville watermark "Ville"]
[text* pays watermark "Pays"][tel* telephone maxlength:12 watermark "Numéro de téléphone"]
[submit "Envoyer"]
</div>
</div>

Thank you 🙂