pyfedi/app/templates/themes/card_shadow/styles.css

.post_list .post_teaser h3 {
    font-size: 14px;
    font-weight: bold;
}

.post_body a, .comment_body a {
    text-decoration: underline;
}

.post_list .post_teaser {
    /* outside space  top right bottom left*/
    margin: 10px 5px 5px 5px;
    /* inside space  top right bottom left*/
    padding: 5px 5px 5px 5px;
    /* border */
    border-left: solid 2px rgba(0,0,0,0.2);
    border-bottom: solid 2px rgba(0,0,0,0.2);
    border-right: solid 1px rgba(0,0,0,0.2);
    border-radius: 5px; /* 5px rounded corners */
    /* shadow */
    box-shadow: 0 4px 8px 0 rgba(0,123,255,0.2);
    transition: 0.3s;
}

[data-bs-theme="dark"] .post_list .post_teaser {
    /* outside space  top right bottom left*/
    margin: 10px 5px 5px 5px;
    /* inside space  top right bottom left*/
    padding: 5px 5px 5px 5px;
    /* border */
    border-left: solid 2px rgba(0,123,255,0.2);
    border-bottom: solid 2px rgba(0,123,255,0.2);
    border-right: solid 1px rgba(0,123,255,0.2);
    border-radius: 5px; /* 5px rounded corners */
    /* shadow */
    box-shadow: 0 4px 8px 0 rgba(0,123,255,0.2);
    transition: 0.3s;
}