main.css

*, *:before, *:after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
  }

body {
    background: #eee;
    font-family: 'Lato', sans-serif;
}

/*------------------------------------*    
                HEADER
\*------------------------------------*/

#header {
    height: 60px;
    display: flex;
    flex-direction: row;
    top: 0;
    justify-content: space-around;
    align-items: center;
    padding: 0 20px;
    position: sticky;
    background: #ddd;

}

#header #header-img {
    width: 100%;
    height: 100%;
    max-width: 300px;
    justify-content: left;
    margin-left: 20px;
}

#header .nav-bar ul {
    display: flex;
    flex-direction: row;
    list-style: none;
    width: 35vw;
    justify-content: space-around;
    font-size: initial;
    
}

#header a {
    text-decoration: none;
    color: black;
}

@media (max-width: 575px){
    #header {
        height: 80px;
        display: flex;
        flex-direction: column;
        top: 0;
        justify-content: center;
        align-items: center;
        position: sticky;
    
    }
    #header #header-img {
        width: 100%;
        height: 100%;
        max-width: 250px;
        justify-content: center;
    }

    #header .nav-bar ul {
        display: flex;
        flex-direction: row;
        list-style: none;
        width: 100%;
        justify-content: flex-end;
        margin-top: 5px;
    }

    #header .nav-bar ul li{
        padding: 0 5px;
    }

}

/*------------------------------------*    
                HERO
\*------------------------------------*/

#hero {
    height: 200px;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    text-align: center;
}

#hero input[type="email"]{
    max-width: 275px;
    width: 100%;
    padding: 5px;
    margin: 10px 0 10px 0;
} 

#hero input[type="submit"]{
    max-width: 150px;
    width: 100%;
    height: 30px;
    margin: 15px 0;
    padding: 0;
    border: none;
    font-weight: bold;
    text-transform: uppercase;
    background: #f1c40f;
    font-size: large;
} 

#hero input[type="submit"]:hover{
    background-color: orange;
    transition: background-color 1s;
}

/*------------------------------------*    
            FEATURES
\*------------------------------------*/

#container {
    max-width: 1000px;
    width: 100%;
    margin: 0 auto;
}

#features {
    margin-top: 30px;
}

#features .features-items {
    display: flex;
    /* flex-direction: row;
    justify-content: center;*/
}

.features-items .icon {
    display: flex;
    align-items: center;
    justify-content: center;
    height: 125px;
    width: 20vw;
    color: darkorange;
}

.features-items .desc {
    display: flex;
    flex-direction: column;
    justify-content: center;
    height: 125px;
    width: 80vw;
    padding: 5px;
}

/*------------------------------------*    
                HOW ITS WORKS
\*------------------------------------*/

#how-its-works {
    display: flex;
    justify-content: center;
    margin-top: 50px;
}

#how-its-works > iframe{
    max-width: 560px;
    width: 100%;
    height: 354px;
}

@media (max-width: 575px){
    #how-its-works > iframe{
        max-width: 340px;
        width: 100%;
        height: 219px;
    }
}

/*------------------------------------*    
                PRICING
\*------------------------------------*/

#pricing {
    display: flex;
    justify-content: space-between;
    margin-top: 60px;
}

#pricing .product{
    border: 1px solid black;
    width: calc(100%/3);
    margin: 10px;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    text-align: center;
}

#pricing .product:hover{
    transform: scale(1.1);
    box-shadow: 0px 0px 17px 2px rgba(196,186,184,1);
}

#pricing .product .title{
    background-color: #ddd;
    color: black;
    width: 100%;
    padding: 15px 0;
    font-weight: bold;
    text-transform: uppercase;
}

.product > h2 {
    margin-top: 15px;
}

.product > ul {
    margin: 15px 0;
}

.product > ul > li {
    list-style: none;
    padding: 3px 0;
}

.product button {
    background-color: #f1c40f;
    border: 0;
    padding: 10px;
}

.product .btn {
    margin: 20px 0;
    padding: 0 20px;
    height: 40px;
}

.product .btn:hover {
     background-color: orange;
    transition: background-color 1s;
}

@media (max-width: 575px){
    #pricing {
        display: flex;
        justify-content: center;
        align-items: center;
        margin-top: 60px;
        flex-direction: column;
    }

    #pricing .product{
        border: 1px solid black;
        width: 300px;
        margin: 10px;
        display: flex;
    }
}

/*------------------------------------*    
                FOOTER
\*------------------------------------*/

#footer{
    background-color: #ddd;
    margin-top: 30px;
    padding: 20px;
}

#footer > ul , #footer > span { 
    display: flex;
    justify-content: flex-end;
}

#footer > ul{
    margin: 5px 0;
}

#footer a {
    color: black;
    text-decoration: none;
}

#footer li {
    list-style: none;
    padding: 0 5px;
}

#footer span {
    margin-top: 5px;
    color: #444;
    font-size: 0,9em;
}