body {
    font-size: 18px;
    font-family: Lucida Grande, Verdana, Arial;
    background-color: #F5F5F5;
    margin: 0;
}
#main {
    max-width: 960px;
    margin: auto;
    /* height: 100vh; */
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}
header {
    background-color: #fff;
    border-bottom: 1px solid #D9D9D9;
    padding: 5px 30px;
}
footer {
    background-color: #fff;
    padding: 10px 30px;
    display: flex;
    justify-content: center;
    gap: 40px;
}
.logo {
    height: 50px;
}
h1 {
    color: #033461;
    text-align: center;
    margin: 30px 30px 0;
}
a {
    color: #000;
    text-decoration-color: transparent;
    transition: all .5s ease;
}
a:visited {
    color: #000;
}
a:hover {
    text-decoration-color: #000;
}

.searchbar {
    background-color: #E3E3E3;
    width: fit-content;
    min-width: 275px;
    border-radius: 30px;
    margin: 0 auto;
    box-shadow: 0px 2px 2px rgba(0, 0, 0, 0.25);
}
.searchbar input {
    background-color: transparent;
    border: none;
    padding: 25px 0 25px 20px;
    font-size: 18px;
    min-width: 220px;
}
.searchbar input:focus-visible {
    outline: none;
}
input[type="search"]::-webkit-search-cancel-button {
    cursor: pointer;
    filter: brightness(0) saturate(100%) invert(15%) sepia(61%) saturate(1711%) hue-rotate(187deg) brightness(93%) contrast(102%);
}
.searchbar button {
    background-color: transparent;
    border: none;
    vertical-align: middle;
    cursor: pointer;
}
.searchbar img {
    height: 30px;
}
.searchbar img:hover, input[type="search"]::-webkit-search-cancel-button:hover {
    filter: brightness(0) saturate(100%) invert(0%) sepia(0%) saturate(7500%) hue-rotate(62deg) brightness(92%) contrast(105%);
}
.search {
    display: flex;
    margin: 30px;
}
.back {
    white-space: nowrap;
    height: auto;
    margin: auto 0;
    display: block;
    width: 0;
}

section {
    background-color: #033461;
    display: flex;
    height: 100%;
    flex-wrap: wrap;
    gap: 30px;
    padding: 30px;
}
.tile {
    background-color: #fff;
    padding: 30px;
    width: calc(33% - 77px);
    flex-grow: 0;
    border-radius: 8px;
}
.tile img {
    height: 150px;
    filter: opacity(100%);
    transition: all .5s ease;
    margin-bottom: 15px;
    box-shadow: 0px 2px 4px rgba(0, 0, 0, 0.25);
}
.tile img:hover {
    filter: opacity(70%);
}
.isbn {
    font-size: 12px;
    color: rgb(0 0 0 / 60%);
    margin-bottom: 0;
}


/* 2 columns */
@media (max-width: 960px) {
    .tile {
        width: calc(50% - 75px);
    }
}

@media (max-width: 720px) {
    .search {
        flex-direction: column-reverse;
        gap: 30px;
    }
    .back {
        width: 100%;
        text-align: center;
    }
    .tile {
        width: calc(50% - 55px);
        padding: 20px;
    }
}

@media (max-width: 576px) {
    section {
        padding: 20px;
        gap: 20px;
    }
    .tile {
        padding: 15px;
        width: calc(50% - 40px);
    }
    .tile img {
        height: 130px;
    }
}

/* mobile */
@media (max-width: 480px) {
    h1 {
        font-size: 1.5em;
        margin: 20px 20px 0;
    }
    .search {
        margin: 20px;
        gap: 20px;
    }
    section {
        padding: 15px;
        gap: 15px;
    }
    .tile {
        width: 100%;
    }
    .tile img {
        height: 100px;
    }
    a, .searchbar input {
        font-size: 15px;
    }
}