style.css

*{
    padding:0;
    margin:0;
    font-family:sans-serif;
    box-sizing: border-box;
}

/* navigation section */
.navigation{
    background-color: rgb(173, 216, 230, 0.3);
    padding:10px 0 1rem 0;
}

/* heading */
h1{
    font-size: 2.5rem;
    text-align: center;
    margin-top: 2rem;
    word-spacing: 10px;
    letter-spacing: 2px;
}

/* selector button wrapper */
.selector-btn-wrapper{
    width: 60%;
    margin:20px auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
}

/* click button */

.btn{
    width: 25%;
    padding:0.3rem;
    font-size: 1.3rem;
    cursor: pointer;
    border-radius: 14px;
    overflow: hidden;
    background-color: green;
    color:white;
    border:none;
}

/* dropdown list */

.dog-breed{
    height: 2rem;
    width: 30%;
    padding:2px;
    font-size: 1.3rem;
    background-color:lightblue;
    border-radius: 12px;
    outline: none;
}

.dog-subBreed{
    width: 30%;
    height: 2rem;
    padding:2px;
    font-size: 1.3rem;
    border-radius: 12px;
    outline:none;
    background-color: lightblue;
}


/* main section */

.main{
    display: flex;
    flex-wrap: wrap;
    row-gap: 1rem;
    column-gap: 1rem;
}

/* image container */
.img-wrapper{
    margin:20px auto;
    height: 400px;
    width: 400px;
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 2px 2px 20px 2px gray;
}


.main img{
    height: 100%;
    width: 100%;
}


@media screen and (max-width:400px){
    .selector-btn-wrapper{
        flex-direction: column;
        row-gap: 1rem;
    }

    .btn{
        width: 80%;
    }

    .dog-breed{
        width: 80%;
    }

    .dog-subBreed{
        width: 80%;
    }
}