Антон Спирин

<input class="js-search" />
<a class="js-search-link" target="_blank" href="#">Search in Google</a>

var defaultHref = 'https://google.com/search?q=';
var search = document.querySelector('.js-search');
var link = document.querySelector('.js-search-link');

link.setAttribute('href', defaultHref);

search.addEventListener('input', function() {
  link.setAttribute('href', defaultHref + search.value.trim().replace(/ +/, '+'));
});

.btn {
    background-image: url(../img/btn.png);
    background-position: 0 0;
    width: 478px;
    height: 152px;
    display: inline-block;
    position: absolute;
    top: 160px;
    left: 0;
    font-size: 20px;
    color: #fff;
    text-shadow: 0 1px 0 rgba(0,0,0,0.53);
    text-align: center;
    line-height: 150px;
}
.btn:hover {
    background-position: 0 -155px;
    padding-top: 2px;
}
.btn:before {
    content: '';
    position: absolute;
    top: 50px;
    right: 40px;
    bottom: 50px;
    left: 40px;
    border: 6px solid transparent;
    border-radius: 50px;
    animation-duration: 1s;
}
.btn:hover:before, .btn:focus:before, .btn:active:before {
    animation-name: hvr-ripple-out;
}
@keyframes hvr-ripple-out {
    100% {
        border-color: #ccc;
        top: -12px;
        right: -12px;
        bottom: -12px;
        left: -12px;
        opacity: 0
    }
}

.content {
  margin-bottom: 400px;
}

.footer {
   position: fixed;
   bottom: 0;
   left: 0;
   right: 0;
   height: 400px;
   z-index: -1;
}

<a href="http://mail.ru" class="item-link item-link_first">item</a>

<a href="http://mail.ru" class="top-menu__item-link item-link_first">item</a>

<a href="http://mail.ru" class="top-menu__item-link_first">item</a>