Reply To: Cart Login field on checkout

Try to use the following CSS code for that purpose

body.woocommerce-checkout .woocommerce-cart-notice {
        border: 2px solid #E0B252;
   border-radius: 0;
   overflow: hidden;
   margin: 0 0 20px 0;
   padding: 14px 25px 14px 55px;
   line-height: 1.4;
   position: relative;
   font-size: 14px;
        color:#AF7D27;
   -webkit-box-sizing: border-box;
   -moz-box-sizing: border-box;
   box-sizing: border-box;
}

body.woocommerce-checkout .woocommerce-cart-notice:before {
        content: "\f071";
}