:root {
    --blue: #2196F3;
    --black: #212121;
    --grey: #AFB1B8;
}
body {
    font-family: 'Roboto', sans-serif;
}

* {
    box-sizing: border-box;
}

textarea {
    resize: none;
}

button {
    cursor: pointer;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding-left: 15px;
    padding-right: 15px;
}

.burger {
    display: none;
    border: none;
    background-color: transparent;
    margin: 0;
    padding: 0;
}

.burger__icon_close {
    display: none;
}

.header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    min-height: 80px;
    background-color: white;
    z-index: 3;
}

.modal-menu {
    position: fixed;
    z-index: 2;
    top: 34px;
    left: 0;
    width: 100%;
    background-color: white;
    display: none;
}

.modal-menu.is-open {
    display: block;
}

.nav-menu__link {
    display: block;
    padding-top: 32px;
    padding-bottom: 32px;
    font-weight: 500;
    font-size: 14px;    
    line-height: 16px;
    color: var(--black);
    text-decoration: none;
}

@media screen and (max-width: 768px) {
    .burger {
        display: block;
    }

    .header .nav-menu, .header .contacts {
        display: none;
    }

    .header {
        min-height: 34px;
    }

    .nav-menu__list {
        display: flex;
        flex-direction: column;
        justify-content: center;
        align-items: center;
        margin-left: 0;
        margin-top: 60px;
        margin-bottom: 60px;
    }
    
    .nav-menu__item {
        margin-right: 0;
    }
    
    .header__inner {
        padding: 16px 15px;
        border-bottom: #ECECEC 1px solid;
    }
    
    .contacts {
        justify-content: center;
        align-items: center;
        margin-bottom: 60px;
    }

    .hero {
        margin-top: 66px;

    }

    .hero__title {
        font-weight: 900;
        font-size: 26px;
        line-height: 42px;
        margin-left: 60px;
        margin-right: 60px;
    }

    .js-speaker-form input {
        width: 100%;
    }
}

@media screen and (max-width: 480px) {
    .burger {
        display: block;
    }

    .advantages__col {
        width: 100%;
    }

    .advantages__title {
        text-align: center;
    }

    .team {
        padding: 60px 0;
    }

    .team__col {
        width: 100%;
    }

    .advantages__text {
        margin-bottom: 30px;
    }

    .clients__col {
        width: 50%;
    } 

    .clients__title {
        padding-top: 60px;
    }

    .clients__list {
        padding: 30px 0 60px 0;
    }
    
    .footer-content{
        display: inline-block;
    }
    
    .footer-wrapper {
        margin-left: 0;
        padding-top: 60px;
    }

    .footer-shirt {
        padding: 0;
    }

    .footer-overlay {
        margin: 60px  0 0 0;
    }

    .footer-mail input {
        margin-right: 0;
    }
}