* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

body {
    min-height: 100vh;
    background-image: linear-gradient(rgba(0, 0, 0, 0.2), rgba(0, 0, 0, 0.4)), url('image/bg-image.jpg');
    background-repeat: no-repeat;
    background-size: cover;
    background-position: left;
    background-attachment: fixed;
}

/* navigation bar  */
nav {
    background: rgba(255, 255, 255, 0.4);
    box-shadow: 3px 3px 5px rgba(0, 0, 0, 0.1);
}

nav ul {
    list-style: none;
    display: flex;
    justify-content: flex-end;
    align-items: center;
}

nav li {
    height: 60px;
}

nav a {
    height: 100%;
    padding: 0 30px;
    text-decoration: none;
    display: flex;
    align-items: center;
    color: black;
}

nav a:hover {
    background-color: #f0f0f0;
}

nav li:first-child {
    margin-right: auto;
}

.sidebar {
    position: fixed;
    top: 0;
    right: 0;
    height: 100vh;
    width: 250px;
    z-index: 999;
    background-color: rgba(255, 255, 255, 0.2);
    backdrop-filter: blur(10px);
    display: none;
    flex-direction: column;
    align-items: flex-start;
    justify-content: flex-start;
}

.sidebar li {
    width: 100%;
}

.sidebar a {
    width: 100%;
}

.menubutton {
    display: none;
}

#subject {
    font-size: 60px;
    align-items: center;
    text-align: center;
    margin-top: 40px;
    color: white;
    text-shadow: 1px 1px 2px black;
}

/* card book section  */
.book {
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 30px 0;
}

.card {
    width: 340px;
    height: 400px;
    border-radius: 20px;
    overflow: hidden;
    border: 8px solid white;
    position: relative;
    margin: 20px;
}

.card:hover .card-body {
    right: 0;
}

.card img {
    width: 100%;
    height: 100%;
    object-fit: cover;

}

.card-body {
    width: 100%;
    height: 100%;
    top: 0;
    right: -100%;
    position: absolute;
    background: #1f3d4738;
    backdrop-filter: blur(4px);
    border-radius: 15px;
    padding: 30px;
    display: flex;
    flex-direction: column;
    justify-content: center;
    transition: 1s;
}

.card-title {
    text-transform: uppercase;
    color: white;
    text-shadow: 1px 1px 2px black;
}

.card-info {
    font-size: 16px;
    margin: 30px 0;
    font-weight: 400;
    color: white;
    text-shadow: 1px 1px 2px black;
}

.card-btn {
    background: #33383b;
    color: white;
    padding: 10px;
    border-radius: 5px;
    border: none;
    outline: none;
    font-weight: 500;
    cursor: pointer;
    width: 120px;
}

.card-btn a {
    text-decoration: none;
    color: white;
}


/* The footer is fixed to the bottom of the page */

footer {
    bottom: 0;
}

.footer-distributed {
    background: rgba(255, 255, 255, 0.4);
    box-sizing: border-box;
    width: 100%;
    text-align: left;
    font: bold 16px sans-serif;
    padding: 50px 50px 60px 50px;
    margin-top: 0px;
}

.footer-distributed .footer-left,
.footer-distributed .footer-center,
.footer-distributed .footer-right {
    display: inline-block;
    vertical-align: top;
}

/* Footer left */

.footer-distributed .footer-left {
    width: 30%;
}

.footer-distributed h3 {
    color: black;
    font: 36px 'Cookie', cursive;
    margin: 0;
}

/* Footer links */

.footer-distributed .footer-links {
    color: black;
    margin: 20px 0 12px;
}

.footer-distributed .footer-links a {
    display: inline-block;
    line-height: 1.8;
    text-decoration: none;
    color: inherit;
}

.footer-distributed .footer-name {
    color: black;
    font-size: 14px;
    font-weight: normal;
    margin: 0;
}

/* Footer Center */

.footer-distributed .footer-center {
    width: 35%;
}

.footer-distributed .footer-center p {
    display: inline-block;
    color: black;
    vertical-align: middle;
    margin: 0;
}

.footer-distributed .footer-center p span {
    display: block;
    font-weight: normal;
    font-size: 14px;
    line-height: 2;
}

.footer-distributed .footer-center p a {
    color: #2c283b;
    text-decoration: none;
}

/* Footer Right */

.footer-distributed .footer-right {
    width: 30%;
}

.footer-distributed .footer-about {
    line-height: 20px;
    color: black;
    font-size: 13px;
    font-weight: normal;
    margin: 0;
}

.footer-distributed .footer-about span {
    display: block;
    color: black;
    font-size: 18px;
    font-weight: bold;
    margin-bottom: 20px;
}

.footer-distributed .footer-icons {
    margin-top: 25px;
}

.footer-distributed .footer-icons a {
    display: inline-block;
    width: 35px;
    height: 35px;
    cursor: pointer;
    background-color: #33383b;
    border-radius: 2px;
    font-size: 20px;
    color: #ffffff;
    text-align: center;
    line-height: 35px;
    margin-right: 3px;
    margin-bottom: 5px;
}

.footer-distributed .footer-icons a:hover {
    background-color: #2c283b;
}

.footer-links a:hover {
    color: #2c283b;
}

@media(max-width: 800px) {
    .hideOnMobile {
        display: none;
    }

    .menubutton {
        display: flex;
    }

    .book {
        flex-direction: column;
    }

    #subject {
        font-size: 40px;
    }

    .card {
        width: 300px;
        height: 400px;
        border-radius: 20px;
        margin: 20px;
    }

    .footer-distributed {
        display: flex;
        flex-direction: column;
        vertical-align: top;
        padding: 25px 30px;
    }

    .footer-distributed .footer-left,
    .footer-distributed .footer-center,
    .footer-distributed .footer-right {
        width: 100%;
    }

    .footer-distributed h3 {
        font-size: 26px;
    }

    .footer-distributed .footer-left {
        margin: 5px 0;
    }

    .footer-distributed .footer-links {
        margin: 10px 0 12px;
    }

    .footer-distributed .footer-about span,
    .footer-distributed .footer-center {
        font-size: 15px;
        margin: 15px 0;
    }

    br {
        display: none;
    }
}