$my-gray-dark: #b1b3b4;

.panel {
    margin-bottom: 20px;
}

.panel__headers {
    display: flex;
}

.panel_headers-item {
    padding: 10px 20px;
    color: $my-gray-dark;
    cursor: pointer;
    position: relative;
}

.panel_headers-item.active::before {
    position: absolute;
    content: '';
    width: 100%;
    height: 1px;
    left: 0;
    bottom: -1px;
    background-color: white;
}

.panel_headers-item.active {
    border: 1px solid $my-gray-dark;
    border-bottom: none;
    border-left: 1px solid $my-gray-dark !important;
}

.panel_headers-item:nth-child(even) {
    border-left: 0;
}

.panel__content {
    border: 1px solid $my-gray-dark;
    padding: 10px 20px;
}