function _array_like_to_array(arr, len) {
    if (len == null || len > arr.length) len = arr.length;
    for(var i = 0, arr2 = new Array(len); i < len; i++)arr2[i] = arr[i];
    return arr2;
}
function _array_with_holes(arr) {
    if (Array.isArray(arr)) return arr;
}
function _define_property(obj, key, value) {
    if (key in obj) {
        Object.defineProperty(obj, key, {
            value: value,
            enumerable: true,
            configurable: true,
            writable: true
        });
    } else {
        obj[key] = value;
    }
    return obj;
}
function _iterable_to_array_limit(arr, i) {
    var _i = arr == null ? null : typeof Symbol !== "undefined" && arr[Symbol.iterator] || arr["@@iterator"];
    if (_i == null) return;
    var _arr = [];
    var _n = true;
    var _d = false;
    var _s, _e;
    try {
        for(_i = _i.call(arr); !(_n = (_s = _i.next()).done); _n = true){
            _arr.push(_s.value);
            if (i && _arr.length === i) break;
        }
    } catch (err) {
        _d = true;
        _e = err;
    } finally{
        try {
            if (!_n && _i["return"] != null) _i["return"]();
        } finally{
            if (_d) throw _e;
        }
    }
    return _arr;
}
function _non_iterable_rest() {
    throw new TypeError("Invalid attempt to destructure non-iterable instance.\\nIn order to be iterable, non-array objects must have a [Symbol.iterator]() method.");
}
function _sliced_to_array(arr, i) {
    return _array_with_holes(arr) || _iterable_to_array_limit(arr, i) || _unsupported_iterable_to_array(arr, i) || _non_iterable_rest();
}
function _unsupported_iterable_to_array(o, minLen) {
    if (!o) return;
    if (typeof o === "string") return _array_like_to_array(o, minLen);
    var n = Object.prototype.toString.call(o).slice(8, -1);
    if (n === "Object" && o.constructor) n = o.constructor.name;
    if (n === "Map" || n === "Set") return Array.from(n);
    if (n === "Arguments" || /^(?:Ui|I)nt(?:8|16|32)(?:Clamped)?Array$/.test(n)) return _array_like_to_array(o, minLen);
}
import { genStyleHooks } from "../Hooks/useStyle";
var genStyle = function genStyle(token) {
    var _obj, _obj1;
    return _obj1 = {}, _define_property(_obj1, token.componentCls, (_obj = {
        // position:relative，在流内正常占位，由父容器负责整体定位。
        // 不使用 position:fixed，避免脱离文档流导致隐藏时 presence 高度塌陷。
        position: 'relative',
        display: 'flex',
        justifyContent: 'center',
        alignItems: 'center',
        width: 32,
        height: 32,
        color: 'var(--color-gray-text-secondary)',
        fontSize: 16,
        background: 'var(--color-gray-bg-card-white)',
        border: 'none',
        boxShadow: 'var(--shadow-control-base)',
        borderRadius: '50%',
        cursor: 'pointer',
        transition: 'all 0.2s ease-in-out'
    }, _define_property(_obj, '&-content', {
        display: 'flex',
        flexDirection: 'column',
        justifyContent: 'center',
        alignItems: 'center',
        textAlign: 'center',
        overflow: 'hidden'
    }), _define_property(_obj, '&:hover', {
        boxShadow: 'var(--shadow-control-lg)'
    }), _define_property(_obj, '&:active', {
        boxShadow: 'var(--shadow-control-base)',
        transform: 'scale(0.95)'
    }), _obj)), // presence wrapper：始终保留在 DOM 中，固定 32×32 尺寸以保持占位空间。
    // 仅通过 opacity + pointer-events 切换显隐，隐藏时内部按钮不可交互但占位不变。
    _define_property(_obj1, "".concat(token.componentCls, "-presence"), {
        width: 32,
        height: 32,
        flexShrink: 0,
        transition: 'opacity 0.18s cubic-bezier(0.4, 0, 0.2, 1)',
        '&[data-state="enter"]': {
            opacity: 1
        },
        '&[data-state="exit"]': {
            opacity: 0,
            pointerEvents: 'none'
        }
    }), _obj1;
};
export var prefixCls = 'back-to';
var useGenStyle = genStyleHooks('BackTo', genStyle);
export function useStyle(prefixCls) {
    var _useGenStyle = _sliced_to_array(useGenStyle(prefixCls !== null && prefixCls !== void 0 ? prefixCls : 'back-to'), 2), wrapSSR = _useGenStyle[0], hashId = _useGenStyle[1];
    return {
        wrapSSR: wrapSSR,
        hashId: hashId
    };
}
