grav-labonneadresse.graphics/user/themes/antimatter/scss/template/_panel.scss

$sidebar-color:     #333;
$panel-padding:     1rem;
$panel-text:        #ddd;

.sb-slidebar {
    background-color: $sidebar-color !important;
}

#panel {
    padding-top: $panel-padding;
    color: $panel-text;
    .navigation {
        list-style: none;
        padding: 0;

        li {
            a {
                color: $panel-text;
                display: block;
                padding: 0.5rem 1rem;
                font-weight: 600;

                &:hover {
                    color: lighten($panel-text,20%);
                    background-color: darken($sidebar-color,5%);
                }

                &:last-child {
                    border-bottom: 0;
                }
            }

            &.active {
                & > a {
                    background: #fff;
                    color: $core-text;
                    &:hover {
                        color: $core-text;
                    }
                }
            }
            border-bottom: 1px solid lighten($sidebar-color,4%);
            &:first-child {
               border-top: 1px solid lighten($sidebar-color,4%);
            }

            ul {
                list-style: none;
                padding: 0;

                li {
                    border: 0 !important;
                    a {
                        color: darken($panel-text, 10%);
                        padding: 0.2rem 1rem 0.2rem 2rem;
                        font-size: 0.9rem;
                    }
                    li a {
                        padding-left: 3rem;
                        li a {
                            padding-left: 4rem;
                        }
                    }
                    &.active {
                        & > a {
                            background: #ccc;
                        }
                    }
                }
            }
        }
    }
}