Alguien sabe porque queda asi? HTML <code>&lt;main class=&quot;container&quot;&gt; &lt;!-- SEARCH --&gt; &lt;section&g...

Alguien sabe porque queda asi?

HTML

<main class="container">

        <!-- SEARCH -->

        <section>
            <div class="section">
                <div class="row">
                    <div class="col m7 input-field input-container">
                        <i class="material-icons">search</i>
                        <input id="search" type="text" placeholder="Search">
                    </div>
                </div>
            </div>
        </section>

        <!-- CARDS -->

        <section>
            <div class="row">
                <article class="col s12 m6 l4">


                    <div class="card">

                        <div class="card-image waves-effect-waves-block waves-light">
                            <img src="assets/img/card1.png" alt="Card One" class="activator"></div>
                        <div class="card-content">
                            <span class="card-title grey-text activator text-darken-4">Citation Longit
                                <i class="material-icons right">more_vert</i>
                            </span>
                            <p><a href="#">See more</a></p>
                        </div>
    
                        <div class="card-reveal">
                            <span class="card-title grey-text text-darken-4"> Citation Longitud<i class="material-icons right">close</i>
                            </span>
                            <p>4 Passenger Range: 3,500 nm </p>
                            <p> Maximum Passengers: 12</p>
                            <a class="waves-effect waves-teal btn-flat teal lighten-5 right" href="post.html">Go!</a>
                        </div>
                    </div>
                </article>
                <article class="col s12 m6 l4">


                    <div class="card">

                        <div class="card-image waves-effect-waves-block waves-light">
                            <img src="assets/img/card2.jpg" alt="Card One" class="activator"></div>
                        <div class="card-content">
                            <span class="card-title grey-text activator text-darken-4">Citation Latitude
                                <i class="material-icons right">more_vert</i>
                            </span>
                            <p><a href="#">See more</a></p>
                        </div>
    
                        <div class="card-reveal">
                            <span class="card-title grey-text text-darken-4"> Citation Latitude<i class="material-icons right">close</i>
                            </span>
                            <p>4 Passenger Range: 2,700 nm </p>
                            <p> Maximum Passengers: 9</p>
                            <a class="waves-effect waves-teal btn-flat teal lighten-5 right" href="post.html">Go!</a>
                        </div>
                    </div>
                </article>
                <article class="col s12 m6 l4">


                    <div class="card">

                        <div class="card-image waves-effect-waves-block waves-light">
                            <img src="assets/img/card3.jpg" alt="Card One" class="activator"></div>
                        <div class="card-content">
                            <span class="card-title grey-text activator text-darken-4">Citation XLS+
                                <i class="material-icons right">more_vert</i>
                            </span>
                            <p><a href="#">See more</a></p>
                        </div>
    
                        <div class="card-reveal">
                            <span class="card-title grey-text text-darken-4"> Citation XLS+<i class="material-icons right">close</i>
                            </span>
                            <p>4 Passenger Range: 2,100 nm </p>
                            <p> Maximum Passengers: 12</p>
                            <a class="waves-effect waves-teal btn-flat teal lighten-5 right" href="post.html">Go!</a>
                        </div>
                    </div>
                </article>
                <article class="col s12 m6 l4">


                    <div class="card">

                        <div class="card-image waves-effect-waves-block waves-light">
                            <img src="assets/img/card4.jpg" alt="Citation CJ4 GEN2" class="activator"></div>
                        <div class="card-content">
                            <span class="card-title grey-text activator text-darken-4">Citation CJ4 
                                <i class="material-icons right">more_vert</i>
                            </span>
                            <p><a href="#">See more</a></p>
                        </div>
    
                        <div class="card-reveal">
                            <span class="card-title grey-text text-darken-4"> Citation CJ4 <i class="material-icons right">close</i>
                            </span>
                            <p>4 Passenger Range: 2,165 nm </p>
                            <p> Maximum Passengers: 10</p>
                            <a class="waves-effect waves-teal btn-flat teal lighten-5 right" href="post.html">Go!</a>
                        </div>
                    </div>
                </article>
                <article class="col s12 m6 l4">


                    <div class="card">

                        <div class="card-image waves-effect-waves-block waves-light">
                            <img src="assets/img/card5.jpg" alt="Citation CJ3+" class="activator"></div>
                        <div class="card-content">
                            <span class="card-title grey-text activator text-darken-4">Citation CJ3+
                                <i class="material-icons right">more_vert</i>
                            </span>
                            <p><a href="#">See more</a></p>
                        </div>
    
                        <div class="card-reveal">
                            <span class="card-title grey-text text-darken-4"> Citation CJ3+<i class="material-icons right">close</i>
                            </span>
                            <p>4 Passenger Range: 2,040 nm </p>
                            <p> Maximum Passengers: 9</p>
                            <a class="waves-effect waves-teal btn-flat teal lighten-5 right" href="post.html">Go!</a>
                        </div>
                    </div>
                </article>
                <article class="col s12 m6 l4">


                    <div class="card">

                        <div class="card-image waves-effect-waves-block waves-light">
                            <img src="assets/img/card6.jpg" alt="Citation M2" class="activator"></div>
                        <div class="card-content">
                            <span class="card-title grey-text activator text-darken-4">Citation M2
                                <i class="material-icons right">more_vert</i>
                            </span>
                            <p><a href="#">See more</a></p>
                        </div>
    
                        <div class="card-reveal">
                            <span class="card-title grey-text text-darken-4"> Citation M2<i class="material-icons right">close</i>
                            </span>
                            <p>4 Passenger Range: 1,550 nm </p>
                            <p> Maximum Passengers: 7</p>
                            <a class="waves-effect waves-teal btn-flat teal lighten-5 right" href="post.html">Go!</a>
                        </div>
                    </div>
                </article>
            </div>
        </section>
    </main>

CSS

.input-field.input-container { /* aplicando el cascade */
    height: 100px;
    float: none;
    display: flex;
    margin: 0 auto;

}

.input-field > #search { /* busca al hijo directo (#search) del input-field */
    margin-top: 25px;
}

.input-container i {
    margin-top: 45px;
    margin-right: 15px;
}

footer.page-footer {

    height: 80px;
    background: gray;
    bottom: 0;
}