.list_search {
    text-align: center;
}
.list_search .input-group {
    min-width: 100%;
}

.list_search .input-group input[type=text] {
    border-radius: 5px 0px 0px 5px !important;
    width: 80% !important;
    float: left;
}
.list_search .input-group-addon {
    width: 20% !important;
    float: right;
    display: flex;
    align-items: center;
    text-align: center;
    justify-content: center;
}