@media (max-width:1600px) {
    .about_abs {
        margin-top: 85px;
    }
}
@media (max-width:1400px) {
    .about_abs {
        margin-right: 80px;
    }
    #about .container {
        padding: 80px 0 75px 21.5%;
    }
}
@media (max-width:1300px) {
    #about .container {
        padding: 80px 0 45px 24.5%;
    }
}
@media (max-width:1250px) {
    .about_abs {
        margin-right: 110px;
        margin-top: 60px;
    }
    #banner_big .h2 {
        font-size: 60px;
        line-height: 68px;
    }
    #banner_big .h3 {
        font-size: 38px;
        line-height: 44px;
    }
    #banner_big .h4 {
        font-size: 22px;
        line-height: 26px;
    }
    #banner_big p {
        font-size: 16px;
        line-height: 18px;
    }
}
@media (max-width:1200px) {
    .about_abs {
        margin-right: 120px;
    }
    #about .container {
        padding: 80px 0 35px 28.5%;
    }
    #carouseltasks .carousel-control-prev {
        left: 50px;
    }
    #carouseltasks .carousel-control-next {
        right: 50px;
    }
}
@media (max-width:1150px) {
    .hidden {
        left: 70px;
    }
    .block_author {
        min-width: 250px;
        max-width: 250px;
    }
}
@media (max-width:1100px) {
    .about_abs {
        margin-right: 100px;
    }
    .flexslider2 .slides .block_question1 img,
    .slides .block_question1 img {
        height: 121px;
    }
    .flexslider2 .slides .block_question3 img,
    .slides .block_question3 img {
        height: 150px;
    }
}
@media (max-width:1050px) {
    #about {
        background: url(../img/bgabout.png) #fff no-repeat -100px 0;
        background-size: contain;
    }
    .link_pages {
        margin-right: 50px;
    }
    #authors .container > .d-flex {
        flex-wrap: wrap;
    }
    .hidden {
        left: 30px;
    }
    #carouseltasks {
        height: 510px;
        padding-top: 20px;
        overflow: hidden;
    }

}
@media (max-width:1030px) {

}
@media (max-width:1018px) {
    .tiger .hover img,
    .tiger .focus img {
        max-width: 150px;
    }
    .hidden {
        left: 0;
        width: 100%;
    }
    .tiger:nth-child(1) .hover + .hidden:before,
    .tiger:nth-child(1) .focus + .hidden:before {
        left: 12%;
    }
    .tiger:nth-child(2) .hover + .hidden:before,
    .tiger:nth-child(2) .focus + .hidden:before {
        left: 27%;
    }
    .tiger:nth-child(3) .hover + .hidden:before,
    .tiger:nth-child(3) .focus + .hidden:before {
        left: 43%;
    }
    .block_question1 {
        margin-top: 20px;
    }
}
@media (max-width:1000px) {
    .about_abs {
        margin-right: 80px;
    }
    #banner_big .h2 {
        font-size: 40px;
        line-height: 48px;
    }
    #banner_big .h3 {
        font-size: 28px;
        line-height: 34px;
    }
    #banner_big .h4 {
        font-size: 18px;
        line-height: 22px;
    }
    #banner_big p {
        font-size: 14px;
        line-height: 16px;
    }

    #reviews .flexslider {
        max-width: 77%;
        margin: 0 auto;
    }
    #carouseltasks .carousel-control-prev,
    #carouseltasks .carousel-control-next {
        background-size: 100%;
    }
    .flexslider2 .slides .block_question1 img {
        height: 100px;
    }
    .block_message {
        width: 220px;
    }
    .block_question1_1 {
        display: none;
    }
    .block_question2  .d-flex div .d-flex > .ml-4 {
        margin-left: 0!important;
    }
}
@media (max-width:978px) {
    .panel_auth {
        padding-bottom: 5px;
    }
    header {
        top: 72px;
    }
    .panel_auth .container {
        justify-content: center!important;
    }
    .panel_auth .contacts-container {
        min-height: 70px;
        align-items: center!important;
    }
    #book .panel_auth .contacts-container {
        min-height: auto;
    }
}
@media (max-width:950px) {
    .about_abs {
        margin-right: 60px;
        margin-top: 50px;
    }
    #banner_big .about_abs a {
        width: 140px;
        font-size: 16px;
        height: 36px;
        line-height: 36px;
    }
    #carouseltasks {
        height: 490px;
    }
    .block_question {
        padding-left: 40px;
    }
    .block_message {
        width: 200px;
    }
    .block_question1 .block_message audio {
        width: 180px!important;
    }
    .flexslider2 .slides .block_question3 img,
    .slides .block_question3 img {
        height: 120px;
    }
}
@media (max-width:900px) {
    #reviews .flexslider {
        max-width: 88%;
    }
    .about_abs {
        margin-right: 40px;
    }
    #carouseltasks {
        height: 465px;
    }
    .tiger .hover img,
    .tiger .focus img {
        max-width: 130px;
    }
    .flexslider2 .slides .block_question1 img, .slides .block_question1 img {
        height: 111px;
        margin-right: 0 !important;
    }
    .block_question2 .d-flex div .d-flex > .ml-4 {
        display: none!important;
    }
    .flexslider2 .slides .block_question3 img, .slides .block_question3 img {
        height: 100px;
    }
    .slides .li2 {
        padding-right: 5em!important;
    }
}
@media (max-width:850px) {
    .about_abs {
        margin-right: 25px;
        margin-top: 40px;
    }
    #banner_big .h2 {
        font-size: 30px;
        line-height: 38px;
    }
    #banner_big .h3 {
        font-size: 22px;
        line-height: 28px;
    }
    #banner_big .h4 {
        font-size: 18px;
        line-height: 22px;
    }
    #carouseltasks {
        height: 440px;
    }
    .flexslider2 .slides .block_question1 img, .slides .block_question1 img {
        height: 91px;
    }
    .block_question {
        margin-bottom: 0;
    }
    .block_submenu a.but_buy {
        padding: 0 5px;
    }
}
@media (max-width:800px) {
    .about_abs {
        margin-right: 10px;
    }
    #about .container {
        padding: 20px 0 15px 10px;
    }
    #heroes .heroes_info {
        min-height: 191px;
    }
    #reviews .flexslider {
        max-width: 100%;
    }

    #carouseltasks {
        /*height: 577px;*/
        /*width: 77%;*/
        margin: 0 auto;
        /*background: url(../img/book.png) no-repeat 0% 0;*/
        /*background-size: auto 100%;*/
        background: none;
        height: auto;
        padding-top: 0;
    }
    #carouseltasks .carousel-control-prev {
        left: -30px;
    }
    #carouseltasks .carousel-control-next {
        right: -30px;
    }
    .flexslider_2 .slides.d-flex {
        flex-wrap: wrap;
        justify-content: flex-start !important;
        width: 520px;
        margin: 0 auto;
    }
    .flexslider2 .slides .block_question1 img, .slides .block_question1 img {
        height: 151px;
    }
    .block_message {
        width: 245px;
    }
    .block_question2 .d-flex div .d-flex > .ml-4 {
        display: flex !important;
    }
    .flexslider2 .slides .block_question3 img, .slides .block_question3 img {
        height: 170px;
    }
    .block_question {
        margin-bottom: 20px;
        padding-left: 0;
    }
    .li2 .block_question {
        padding-left: 0;
    }
    .flexslider2 .slides .block_question2 img, .slides .block_question2 img {
        height: 100px;
    }
    .flexslider2 .slides .block_question2 img, .slides .block_question2 img.mx-4 {
        margin: 0 2.55em!important;
    }
    .block_question2 .d-flex div .d-flex > .ml-4 img.mx-4 {
        margin: 0 2.55em 2em!important;
    }
    .block_question1_1 {
        display: block;
    }
    header.sheensay_fixed .block_submenu a {
        display: inline-block;
    }
    .use__row {
        overflow: hidden;
    }
    .use__row img {
        display: none;
    }
}
@media (max-width:770px) {
    .tiger .hover img,
    .tiger .focus img {
        max-width: 120px;
    }
}
@media (max-width:750px) {
    header {
        top: 61px;
    }
    #banner_big {
        overflow: hidden;
    }
    .about_abs {
        margin-right: -10px;
    }
    #banner_big .h2 {
        font-size: 25px;
        line-height: 33px;
    }
    #banner_big .h3 {
        font-size: 20px;
        line-height: 26px;
    }
    #banner_big .h4 {
        font-size: 16px;
        line-height: 20px;
    }
    #banner_big .about_abs a {
        width: 120px;
        font-size: 14px;
        height: 32px;
        line-height: 32px;
    }
    .tiger .hover img,
    .tiger .focus img {
        max-width: 110px;
    }
}
@media (max-width:700px) {
    .about_abs {
        margin-right: -25px;
        margin-top: 30px;
    }
    .hidden span {
        font-size: 30px;
        line-height: 38px;
        margin: 9px 24px 15px 5px;
    }
    #reviews .flexslider {
        max-width: 370px;
    }
    h3 {
        font-size: 30px;
        line-height: 37px;
    }
    .but_teachers {
        margin-left: 300px;
    }
}
@media (max-width:677px) {
    header {
        top: 88px;
    }
    .registration__textbook {
        margin-top: 40px;
    }
    .panel_auth .contacts-container {
        min-height: 83px;
    }
}
@media (max-width:661px) {
    header {
        top: 64px;
    }
    .block_submenu a {
        font-size: 16px;
        margin-right: 20px;
    }
    .about_abs {
        margin-right: -35px;
        margin-top: 20px;
    }
    #banner_big .about_abs a {
        width: 100px;
    }
    #about .container {
        padding-left: 0;
    }
    .tiger .hover img,
    .tiger .focus img {
        max-width: 100px;
    }
    h3 {
        font-size: 25px;
        line-height: 32px;
    }
    .but_teachers {
        margin-left: 250px;
    }
    #for_teachers hr {
        margin-top: -13px;
    }
}
@media (max-width:636px) {
    header {
        top: 88px;
    }
}
@media (max-width:610px) {
    section#for_teachers .nav-tabs .nav-link {
        margin-right: 0;
    }
}
@media (max-width:600px) {
    header {
        top: 64px;
    }
    .about_abs {
        width: 311px;
        margin-right: 40px;
    }
    .tiger .hover img,
    .tiger .focus img {
        max-width: 80px;
    }
    .hover + .hidden:before {
        top: -26px;
        height: 26px;
        width: 20px;
        background: url(../img/bghidden.png) no-repeat 0 0;
        background-size: cover;
    }
    #heroes .heroes_info {
        min-height: 221px;
    }
    .tiger:nth-child(1) .hover + .hidden:before,
    .tiger:nth-child(1) .focus + .hidden:before {
        left: 15%;
    }
    .tiger:nth-child(2) .hover + .hidden:before,
    .tiger:nth-child(2) .focus + .hidden:before {
        left: 30%;
    }
    .tiger:nth-child(3) .hover + .hidden:before,
    .tiger:nth-child(3) .focus + .hidden:before {
        left: 43%;
    }
    .tiger:nth-child(5) .hover + .hidden:before,
    .tiger:nth-child(5) .focus + .hidden:before {
        left: 70%;
    }
    .tiger:nth-child(6) .hover + .hidden:before,
    .tiger:nth-child(6) .focus + .hidden:before {
        left: 80%;
    }
}
@media (max-width:584px) {
    header {
        top: 88px;
    }
}
@media (max-width:580px) {
    .but_teachers {
        margin-left: 0;
        margin-top: 0;
    }
}
@media(max-width: 572px) {
    #book #nav {
        top: 97px;
    }
}
@media (max-width:560px) {
    .block_submenu a.but_buy {
        width: 72px;
        height: 32px;
    }
    #reviews h3 {
        text-align: left!important;
    }
}
@media (max-width:540px) {
    .about_abs {
        margin-right: 20px;
    }
    #banner_big .h2 {
        margin-bottom: 0;
    }
    #banner_big p {
        margin-bottom: 5px;
    }
    .block_submenu a {
        font-size: 14px;
        margin-right: 10px;
    }
    header .block_submenu .container {
        min-height: 43px;
    }
    .hidden span {
        font-size: 20px;
        line-height: 28px;
        margin: 9px 24px 15px 5px;
    }
}
@media (max-width:500px) {
    .tiger .hover img,
    .tiger .focus img {
        max-width: 70px;
    }
    .hidden {
        top: 140%;
    }
    #heroes .heroes_info {
        min-height: 241px;
    }
    .about_abs {
        margin-right: 10px;
        margin-top: 10px;
    }
    #banner_big .h2 {
        font-size: 22px;
        line-height: 30px;
    }
    #banner_big .h3 {
        font-size: 18px;
        line-height: 24px;
    }
    #banner_big .h4 {
        font-size: 16px;
        line-height: 20px;
    }
    .flexslider2 .slides .block_question3 img, .slides .block_question3 img {
        height: 120px;
    }
    .flexslider2 .slides .block_question2 img, .slides .block_question2 img {
        height: 70px;
    }
    .flexslider2 .slides .block_question2 img, .slides .block_question2 img.mx-4,
    .block_question2 .d-flex div .d-flex > .ml-4 img.mx-4 {
        margin: 0 1.8em!important;
    }
    .flexslider2 .slides .block_question1 img, .slides .block_question1 img {
        height: 131px;
    }
    .flexslider_2 .slides.d-flex {
        width: 100%;
    }
    .block_message {
        width: 205px;
    }
    #tasks h3 {
        margin-bottom: 20px;
    }
    #tasks {
        padding: 30px 0 20px;
    }
}
@media (max-width:460px) {
    header.sheensay_fixed .block_submenu a {
        font-size: 14px;
        line-height: 19px;
    }
    .link_pages {
        min-width: 150px;
        font-size: 14px;
        line-height: 17px;
        margin-right: 30px;
    }
    #about {
        background: #fff;
    }
    #about .container .pages {
        flex-wrap: wrap;
    }
    .hidden > .d-flex {
        flex-wrap: wrap;
    }
    .hidden span {
        margin: 0 auto;
    }
    .panel_auth .contacts-container {
        min-height: auto;
        margin-bottom: 13px;
    }
    #book .panel_auth .contacts-container {
        margin-bottom: 0;
    }
}
@media (max-width:450px) {
    .block_submenu a {
        margin-right: 5px;
    }
    #banner_big {
        height: 170px;
    }
    #banner_big img {
        display: none;
    }
    .about_abs {
        width: 100%;
        margin: 10px 0;
    }
}
@media (max-width:430px) {
    .block_question1 {
        display: none;
    }
    .block_question2 .d-flex div > .d-flex {
        display: block!important;
    }
    .block_question2 .d-flex div > .d-flex.text-center {
        display: flex!important;
    }
    .block_question2 .d-flex.align-items-center div > .d-flex {
        padding-left: 50px;
        justify-content: flex-end;
    }
}
@media (max-width:420px) {
    #heroes .bg .container > .d-flex {
        flex-wrap: wrap;
    }
    .tiger .hover img,
    .tiger .focus img {
        max-width: 120px;
    }
    .hidden {
        min-height: 200px;
    }
    .tiger:nth-child(1) .hidden,
    .tiger:nth-child(2) .hidden,
    .tiger:nth-child(3) .hidden {
        top: 66%;
        z-index: 99;
    }
    .tiger:nth-child(1) .hover + .hidden:before,
    .tiger:nth-child(4) .hover + .hidden:before,
    .tiger:nth-child(1) .focus + .hidden:before,
    .tiger:nth-child(4) .focus + .hidden:before {
        left: 20%;
    }
    .tiger:nth-child(2) .hover + .hidden:before,
    .tiger:nth-child(5) .hover + .hidden:before,
    .tiger:nth-child(2) .focus + .hidden:before,
    .tiger:nth-child(5) .focus + .hidden:before {
        left: 50%;
    }
    .tiger:nth-child(3) .hover + .hidden:before,
    .tiger:nth-child(3) .focus + .hidden:before {
        left: 80%;
    }
    .tiger:nth-child(4) .hidden,
    .tiger:nth-child(5) .hidden,
    .tiger:nth-child(6) .hidden {
        top: 115%;
    }
}
@media (max-width: 380px) {
    .block_question2 .d-flex.align-items-center div > .d-flex {
        padding-left: 30px;
    }
}