Почему высота div фиксируется на определенное значение, если высота не установлена?

  .section-steps{
        background-color: #ede3e3;
    }
    .steps-box{
       
    }
    .steps-box:first-child{
         text-align: right;
        padding-right: 3%;
         margin-top: 30px;
    }
    .steps-box:last-child{
       padding-left: 3%;
        margin-top: 75px;
    }
    .app-screen{
        width: 40%;
    }
    .works-step{
        margin-bottom: 50px;
    }
    .works-step:last-of-type{
        margin-bottom: 80px;
    }
    .works-step span{
        color: #e67e22;
        border: 2px solid #e67e22;
        display: inline-block;
        border-radius: 50%;
        height: 55px;
        width: 55px;
        text-align: center;
        padding: 5px;
        font-size: 150%;
        margin-right: 25px;
    }
.works-step p { 
display: inline-block;
}
    
    .button-app img{
        height: 50px;
        width: auto;
        margin-right: 10px;
    }

    <section class = "section-steps">
       <div class = "row">
          <h2>How it works &mdash; simple as 1, 2, 3</h2>
       </div>
       <div class = "row">
          <div class = "col span_1_of_2 steps-box">
             <img src = "Resource/img/app-iPhone.png" alt = "Omnifood app on iPhone" class = "app-screen">
          </div>
          <div class = "col span_1_of_2 steps-box">
             <div class = "works-step">
                <span>1</span>
                <p>Choose the subscription plan that best fits your needs and sign up today.</p>
             </div>
             <div class = "works-step">
                <span>2</span>
                <p>Order your delicious meal using our mobile app or website. Or you can even call us!</p>
             </div>
             <div class = "works-step">
                <span>3</span>
                <p>Enjoy your meal after less than 20 minutes. See you the next time!</p>
             </div>
             <a href = "#" class = "button-app"><img src = "Resource/img/download-app.svg" alt = "App Store Button"></a>
             <a href = "#" class = "button-app"><img src = "Resource/img/download-app-android.png" alt = "Play Store Button"></a>
          </div>
       </div>
    </section>