.treeselect {
    position: relative;
    user-select: none;

    /* Размеры контрола (Bootstrap 4 .form-control) */
    --input-height: calc(1.5em + .75rem + 2px);
    --cs-padding-x: .75rem;

    /* Стрелка; в скине заменяется на другой цвет/форму */
    --cs-arrow-svg: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' width='4' height='5' viewBox='0 0 4 5'%3e%3cpath fill='%23333' d='M2 0L0 2h4zm0 5L0 3h4z'/%3e%3c/svg%3e");

    /* Иконки валидации (цвета Bootstrap 4) */
    --cs-valid-icon: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' width='8' height='8' viewBox='0 0 8 8'%3e%3cpath fill='%235cb85c' d='M2.3 6.73L.6 4.53c-.4-1.04.46-1.4 1.1-.8l1.1 1.4 3.4-3.8c.6-.63 1.6-.27 1.2.7l-4 4.6c-.43.5-.8.4-1.1.1z'/%3e%3c/svg%3e");
    --cs-invalid-icon: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2020/svg' width='12' height='12' fill='none' stroke='%23d9534f' viewBox='0 0 12 12'%3e%3ccircle cx='6' cy='6' r='4.5'/%3e%3cpath stroke-linejoin='round' d='M5.8 3.6h.4L6 6.5z'/%3e%3ccircle cx='6' cy='8.2' r='.6' fill='%23d9534f' stroke='none'/%3e%3c/svg%3e");
    --cs-icon-size: calc(0.73em + 0.25rem);
    --cs-validation-padding-right: calc(0.75em + var(--cs-padding-x) + 1.375rem);

    /* Выпадающий список (Bootstrap 4 $dropdown-*; при BS5 переопределяются в скине) */
    --bs-dropdown-padding-y: .5rem;
    --bs-dropdown-bg: #fff;
    --bs-dropdown-border-color: rgba(0, 0, 0, .15);
    --bs-dropdown-border-radius: .25rem;
    --bs-dropdown-box-shadow: 0 .5rem 1rem rgba(0, 0, 0, .175);

    /* Элементы списка (Bootstrap 4 $dropdown-item-padding-*) */
    --bs-dropdown-item-padding-y: .1rem;
    --bs-dropdown-item-padding-x: 1.5rem;

    /* Теги выбранных значений */
    --treeselect-tag-bg: #e2e3e5;
    --treeselect-tag-border-color: #d6d8db;
}

.treeselect-input {
    display: flex;
    flex-wrap: wrap;
    row-gap: 2px;
    height: auto;
    min-height: var(--input-height);
    padding-right: calc(var(--cs-padding-x) + 1rem);
    background-image: var(--cs-arrow-svg);
    background-repeat: no-repeat;
    background-position: right var(--cs-padding-x) center;
    background-size: 8px 10px;
}

.treeselect-list {
    display: none;
    position: absolute;
    margin-top: 1px;
    width: 100%;
    max-height: 300px;
    overflow-y: auto;
    z-index: 500;
    padding: var(--bs-dropdown-padding-y) 0;
    background-color: var(--bs-dropdown-bg);
    border: 1px solid var(--bs-dropdown-border-color);
    border-radius: var(--bs-dropdown-border-radius);
    box-shadow: var(--bs-dropdown-box-shadow);
}

.top.treeselect-list {
    bottom: 100%;
    margin-bottom: 1px;
    margin-top: 0;
}

.treeselect-item {
    padding: var(--bs-dropdown-item-padding-y) var(--bs-dropdown-item-padding-x);
}

.treeselect-value {
    margin-right: 5px;
    padding: 1px 5px;
    cursor: pointer;
    background-color: var(--treeselect-tag-bg);
    border: 1px solid var(--treeselect-tag-border-color);
    border-radius: .2rem;
    line-height: 1;
}

.treeselect-item-line {
    display: flex;
    align-items: center;
}

.treeselect-item input[type=checkbox] {
    width: 16px;
    height: 16px;
    flex-grow: 0;
    flex-shrink: 0;
    margin-right: 5px;
}

.treeselect-item-label {
    cursor: pointer;
}

.treeselect-item-collapse {
    cursor: pointer;
    margin-right: 5px;
    font-size: 13px;
}

.treeselect[data-single="true"] .treeselect-input {
    align-items: center;
    cursor: pointer;
}

.treeselect-input.is-valid {
    padding-right: var(--cs-validation-padding-right);
    background:
        var(--cs-arrow-svg) right var(--cs-padding-x) center/8px 10px no-repeat,
        #fff var(--cs-valid-icon) center right calc(var(--cs-padding-x) + 1rem)/var(--cs-icon-size) var(--cs-icon-size) no-repeat;
}

.treeselect-input.is-invalid {
    padding-right: var(--cs-validation-padding-right);
    background:
        var(--cs-arrow-svg) right var(--cs-padding-x) center/8px 10px no-repeat,
        #fff var(--cs-invalid-icon) center right calc(var(--cs-padding-x) + 1rem)/var(--cs-icon-size) var(--cs-icon-size) no-repeat;
}