body {
    margin: 0;
    padding: 0;
    font-family: sans-serif;
}
.header {
    background-color: #fff;
    color: #000;
    margin-top: 0;
    margin-bottom: 0;
    margin-left: 10px;
    margin-right: 10px;
}
.navbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
}
.nav-logo {
    font-size: 24px;
}
.heading a {
    text-decoration: none;
    color: #000;
}
.heading a:hover {
    color: #ff0000;
    transition: 0.4s;
}
.heading:hover {
    color: #ff0000;
    transition: 0.4s;
}
.nav-list {
    display: flex;
    align-items: center;
    width: 400;
    height: 100px;
    margin: 5px;
}
.nav-list:hover {
    color: #ff0000;
}
.nav-list ul {
    display: flex;
    text-decoration: none;
    list-style: none;
    margin-left: 10px;
    margin-right: 10px;
}
.nav-list ul li a:hover {
    color: #ff0000;
    transition: 0.4s;
}
ul li a {
    text-decoration: none;
    text-transform: uppercase;
    margin-left: 15px;
    margin-right: 15px;
    color: #000;
}
.btn-kirish a:hover {
    color: #fff;
}
.btn-kirish a {
    color: #000;
}

.btn-kirish {
    background-color: #fff;
    color: #000;
    border: 1px solid #ff0000;
    padding-left: 35px;
    padding-right: 35px;
    padding-top: 10px;
    padding-bottom: 10px;
    border-radius: 6px;
    text-decoration: none;
    text-transform: capitalize;
}
.btn-royhatdan-otish {
    color: #fff;
    text-decoration: none;
    background-color: #ff0000;
    border: 1px solid #ff0000;
    padding-left: 35px;
    padding-right: 35px;
    padding-top: 10px;
    padding-bottom: 10px;
    border-radius: 6px;
}

.btn-kirish:hover {
    background-color: #ff0000;
    color: #fff;
    transition: 0.5s;
    cursor: pointer;
}

.btn-royhatdan-otish:hover {
    background-color: #fff;
    color: #000;
    transition: 0.5s;
    cursor: pointer;
}

/* hero */

.site-hero {
    background-color: #eee;
    width: 1535px;
    height: 600px;
}
.hero {
    margin-top: 0;
    margin-bottom: 25px;
    margin-left: 25px;
    margin-right: 25px;
}
.hero-heading {
    margin: 30px 50px 30px 50px;
}
.book-block {
    display: flex;
    justify-content: start;
    align-items: center;
    margin: 10px;
}
.algebra {
    width: 300px;
    height: 425px;
    border-radius: 20px;
    border: 3px solid #ff0000;
}
.algebra-img {
    margin-left: 50px;
    margin-top: 5px;
}
.algebra-heading {
    margin-left: 15px;
}
.algebra-text {
    margin-left: 8px;
}
button {
    background-color: #000;
    color: #fff;
    padding: 10px 25px;
    margin-left: 10px;
    border: 0;
    border-radius: 20px;
}
button a {
    text-decoration: none;
    color: #fff;
}
.algebra:hover {
    background-color: #ff0000;
    transition: 0.6s;
    width: 325px;
    height: 450px;
    padding: 20px;
}
.geometriya {
    width: 300px;
    border-radius: 20px;
    height: 425px;
    margin: 20px;
    border: 3px solid #ff0000;
}
.geometriya-img {
    margin-left: 50px;
    margin-top: 5px;
}
.geometriya-heading {
    margin-left: 15px;
}
.geometriya-text {
    margin-left: 8px;
}
.geometriya:hover {
    background-color: #ff0000;
    transition: 0.6s;
    width: 325px;
    height: 450px;
    padding: 20px;
}

/* footer */
.footer {
    background-color: #ddd;
    color: #000;
    font-family: sans-serif;
}
.footer-list {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-left: 35px;
    margin-right: 35px;
}
.footer-img {
    width: 450px;
    height: 80px;
    font-family: sans-serif;
    font-size: 20px;
}
.footer-social {
    color: #000;
}
.footer-link {
    display: flex;
    justify-content: space-around;
    align-items: center;
}
.footer-link {
    padding: 50px;
    background-color: #ddd;
    font-weight: 10px;
    letter-spacing: 0.7;
}
.footer-link ul{
    list-style: none;
}

.footer-link ul li a:hover {
    transition: 0.4s;
    color: #ff0000;
}
.author {
    padding-left: 25px;
    padding-bottom: 15px;
}