.wc-pincode-checker {
    max-width: 100%;
}

.wc-pincode-checker input.check_pincode {
    width: 100%;
    box-sizing: border-box;
    margin-bottom: 10px;
}

.wc-pincode-checker button.check_pincode_btn {
    width: 100%;
    box-sizing: border-box;
}