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

html,
body {
    height: 100%;
    width: 100%;
}

.header {
    background-color: #c1e8f9;
    text-align: center;
    font-size: 28px;

}

.more {
    height: 1px;
    visibility: hidden;
    overflow-x: hidden;
    display: none;
}

.header-text {
    color: #173874;
    padding: 5px;
    margin: 0 auto;
}

.wrapper {
    background-color: #8bbad0;
    overflow: hidden;
    min-height: 100%;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
}

.nav {
    padding: 5px 10px;
    background-color: #efefef;
    width: 100%;
    display: flex;
    justify-content: end;
    align-items: center;
}

.menu {
    width: 250px;
    padding: 20px 10px;
    background-color: #c1e8f9;
    border: 1px solid #ccc;
    border-radius: 5px;
    height: 90%;
    align-self: auto;
    margin-right: 25px;
}

.menu li {
    list-style: none;
    padding: 0px;
}

.menu li a {
    font-size: 25px;
    display: block;
    padding: 15px;
    margin: 0;
}

.menu li a:link,
.menu li a:visited {
    text-decoration: none;
}

.menu li a:hover {
    background-color: #9adef9;
}

.menu li a:active {
    background-color: #69c2d2;
}

.menu li a:focus {
    background-color: #a5c3e6;
}

.main-wrapper {
    display: flex;
    flex-wrap: nowrap;
    justify-content: center;
    align-items: center;
}

.main-img {
    text-align: center;
}

.main-wrapper img {
    width: 100%;
}

.main-title {
    text-align: center;
    font-size: 25px;
    color: #173874;
    margin: 5px 0px;
    font-weight: bold;
}

.main-content {
    padding: 30px 100px 20px;
    background-color: #b9d4e0;
}

.main-text {
    font-size: 22px;
    max-width: 480px;
    text-align: center;
    margin: 0 auto;
}

.footer {
    border-top: 1px solid #ccc;
    background-color: #d4d4d4;
    text-align: center;
    font-size: 17px;
    padding: 15px 0;
    color: #473f3f;
}

.hidden {
    visibility: hidden;
    overflow-x: hidden;
    display: none;
}

.keywords {
    font-weight: 600;
    color: #0a2a46;
}

@media (max-width: 992px) {
    .main-wrapper {
        flex-wrap: wrap;
        flex-direction: column;
    }

    .menu {
        width: 100%;
        text-align: center;
        padding: 0;
        border: 0;
        margin: 0;
    }

    .menu li:nth-child(even) {
        background-color: #b9d4e0;
    }

    .menu li a {
        font-size: 30px;
        padding: 5px;
    }

    .menu a:hover {
        background-color: #809da8;
    }

    .menu a:active {
        background-color: #6e7abd;
    }

    .menu a:focus {
        background-color: #6b85a3;
    }

    .main-content {
        width: 100%;
        padding: 20px 30px 30px;
    }

    .header {
        background-color: #7cb0c6;
        font-size: 40px;
    }

    .main-text {
        font-size: 26px;
    }

    .main-title {
        font-size: 30px;
    }

    .footer {
        font-size: 19px;
    }
}

@media (max-width: 576px) {
    .more {
        background-image: url("https://rukhlovka.github.io/study/js-dom/img/burger.png");
        background-color: #7cb0c6;
        position: absolute;
        background-repeat: no-repeat;
        background-size: cover;
        background-position: center;
        border: 0;
        width: 44px;
        height: 44px;
        display: block;
        visibility: visible;
        overflow-x: auto;
        right: 0;
        top: 0;
    }

    .more:visited {
        background-color: #7cb0c6;
    }

    .more:hover {
        background-color: #6ebee0;
    }

    .more:active {
        background-color: #4e8ba4;
    }

    .more:focus {
        background-color: #49a3c9;
    }

    .menu-ul {
        display: none;
    }

    .menu li a {
        font-size: 24px;
    }

    .open {
        display: block;
    }

    .header {
        font-size: 30px;
    }

    .main-text {
        font-size: 22px;
    }

    .main-title {
        font-size: 24px;
    }
}

@media (max-width: 356px) {
    .header {
        font-size: 20px;
    }
}