Copy what you want to modify from the cart tab css and paste it in your child theme’s css.
Here’s an example of my child theme’s css:
.woocommerce-cart-tab{
background-color: #FFF !important;
background-image: url(“data:image/svg+xml;charset=UTF-8,%3csvg version=’1.1′ xmlns=’https://www.w3.org/2000/svg’ width=’54’ height=’56’ viewBox=’0 0 26 28′ xml:space=’preserve’ class=’woocommerce-cart-tab__icon’%3e%3cdefs%3e%3clinearGradient id=’a’ x1=’5.961′ x2=’27.37′ y1=’11.796′ y2=’10.952′ gradientTransform=’matrix(1.0613 0 0 1.2004 -1.143 -2.2)’ gradientUnits=’userSpaceOnUse’%3e%3cstop stop-color=’%230f0′ offset=’0’/%3e%3cstop stop-color=’%230f0′ stop-opacity=’0′ offset=’1’/%3e%3c/linearGradient%3e%3c/defs%3e%3ctitle%3eshopping-cart%3c/title%3e%3cpath d=’M10 24c0 1.094-.906 2-2 2s-2-.906-2-2 .906-2 2-2 2 .906 2 2zm14 0c0 1.094-.906 2-2 2s-2-.906-2-2 .906-2 2-2 2 .906 2 2zm2-17v8c0 .5-.391.938-.891 1L8.797 17.906c.078.359.203.719.203 1.094 0 .359-.219.688-.375 1H23c.547 0 1 .453 1 1s-.453 1-1 1H7c-.547 0-1-.453-1-1 0-.484.703-1.656.953-2.141L4.187 6H1c-.547 0-1-.453-1-1s.453-1 1-1h4c1.047 0 1.078 1.25 1.234 2H25c.547 0 1 .453 1 1z’/%3e%3cpath d=’M5.842 6.923L7.776 17.01l16.923-1.884V6.862z’ fill=’url(%23a)’ stroke=’%23230000′ stroke-width=’1.129’/%3e%3c/svg%3e”);
background-repeat: no-repeat;
background-position: 3px -5px;
}
.woocommerce-cart-tab__contents {
background-color: #008600 !important;
margin-bottom: -2px;
width: 23px !important;
height: 23px !important;
line-height: 20px !important;
//border: 2px solid #000;
color: #FFF !important;
font-weight: 700 !important;
}
.woocommerce-cart-tab .woocommerce-cart-tab__icon {
position: absolute;
top: 48% !important;
left: 43% !important;
transform: translateX(-50%) translateY(-50%);
width: 50px !important;
}
.woocommerce-cart-tab p{
font-family: helvetica, arial;
font-weight: 600;
font-size: 14px;
margin-left: 7px;
margin-top: 53px;
}