nav {
    width: 100%;
    height: 80px;
    position: fixed;
    z-index: 1000;
    top: 0;
    left: 0;
    /* fallback for old browsers */
    background: -webkit-linear-gradient(to left, #7f7fd5, #86a8e7, #91eae4);
    /* Chrome 10-25, Safari 5.1-6 */
    background: linear-gradient(to left, #7f7fd5, #86a8e7, #91eae4);
    /* W3C, IE 10+/ Edge, Firefox 16+, Chrome 26+, Opera 12+, Safari 7+ */
    backdrop-filter: blur(25px);
    -webkit-backdrop-filter: blur(25px);
    box-shadow: 0 1px 15px rgba(0, 0, 0, 0.3);
}

.logo_menu {
    padding: 0 0 0 60px;
}

.logo_menu img {
    height: 80px;
}

nav ul {
    margin: 0 60px 0 0;
    float: right;
}

nav ul li {
    display: inline-block;
    line-height: 80px;
    /*margin: 0 20px 0 0;*/
}

nav ul li a {
    color: white;
    font-size: 13px;
    letter-spacing: .5px;
    font-weight: 400;
    margin-left: 12px;
    padding: 6px 10px;
    background: transparent;
    border-radius: 7px;
    border: 1px solid transparent;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0);
    transition: all 0.4s ease;
}

nav ul li a:hover {
    color: white;
    background: rgba(0, 0, 0, 0.2);
}

.checkbtn {
    font-size: 22px;
    color: white;
    float: right;
    line-height: 65px;
    margin: 0 30px 0 0;
    cursor: pointer;
    display: none;
}

#check {
    display: none;
}

/* RESPONSIVE */

@media (max-width: 1200px) {

    nav {
        height: 65px;
    }

    .logo_menu img {
        height: 65px;
    }

    .logo_menu {
        padding: 0 0 0 30px;
    }

    .checkbtn {
        display: block;
    }

    nav ul {
        position: absolute;
        width: 100%;
        height: 100vh;
        background: -webkit-linear-gradient(to left, #7f7fd5, #86a8e7, #91eae4);
        background: linear-gradient(to left, #7f7fd5, #86a8e7, #91eae4);
        top: 65px;
        left: -100%;
        text-align: center;
        transition: all 0.3s;
    }

    nav ul li {
        display: block;
        margin: 40px 0;
        line-height: 30px;
    }

    nav ul li a {
        display: block;
        margin:  0 30px;
        font-size: 16px;
        padding-bottom: 6px;
    }

    #check:checked~ul {
        left: 0;
    }

}

@media (max-width: 600px) {

    .checkbtn {
        line-height: 55px;
    }

    nav {
        height: 55px;
    }

    .logo_menu img {
        height: 55px;
    }

    .logo_menu {
        padding: 0 0 0 30px;
    }

    .checkbtn {
        display: block;
    }

    nav ul {
        top: 55px;
    }

    nav ul li {
        margin: 30px 0;
    }

}