function themeSweep(newTheme, callback) {
    var veil = document.createElement('div');
    var gradient = newTheme === 'dark'
        ? 'linear-gradient(135deg,rgba(2,6,23,0.18),rgba(15,23,42,0.55) 45%,rgba(30,41,59,0.36))'
        : 'linear-gradient(135deg,rgba(255,247,237,0.28),rgba(252,250,245,0.62) 45%,rgba(254,243,199,0.32))';

    veil.style.cssText =
        'position:fixed;inset:0;z-index:9999;pointer-events:none;' +
        'background:' + gradient + ';' +
        'opacity:0;transition:opacity 0.42s cubic-bezier(0.22,0.61,0.36,1);' +
        'will-change:opacity;contain:paint;';
    document.body.appendChild(veil);

    var cleaned = false;
    function cleanup() {
        if (cleaned) return;
        cleaned = true;
        if (veil.parentNode) veil.parentNode.removeChild(veil);
    }

    var applied = false;
    function applyTheme() {
        if (applied) return;
        applied = true;
        callback();
        veil.style.opacity = '0';
    }

    veil.offsetWidth;
    veil.style.opacity = '1';

    setTimeout(applyTheme, 300);
    veil.addEventListener('transitionend', function(e) {
        if (!applied || e.propertyName !== 'opacity') return;
        cleanup();
    });
    setTimeout(function() {
        applyTheme();
        cleanup();
    }, 950);
}

// Toast Message Helper
window.showToast = function(text, type) {
    if (window.Toast) {
        var t = type || 'info';
        if (typeof window.Toast[t] === 'function') {
            window.Toast[t](text);
        } else {
            window.Toast.info(text);
        }
    }
};

// Theme Toggle Logic
window.initThemeToggle = function() {
    var avatar = document.getElementById('theme-toggle-avatar');
    if (!avatar) return;

    var newAvatar = avatar.cloneNode(true);
    avatar.parentNode.replaceChild(newAvatar, avatar);

    newAvatar.addEventListener('click', function(e) {
        e.preventDefault();

        var html = document.documentElement;
        var currentTheme = html.getAttribute('data-theme');
        var newTheme = currentTheme === 'dark' ? 'light' : 'dark';

        var apply = function() {
            html.setAttribute('data-theme', newTheme);
            localStorage.setItem('theme', newTheme);
            window.showToast('已切换至 ' + (newTheme === 'dark' ? '深色' : '浅色') + '模式', 'success');
            if (window.artalk && typeof window.artalk.setDarkMode === 'function') {
                window.artalk.setDarkMode(newTheme === 'dark');
            }
            window.dispatchEvent(new Event('resize'));
        };

        themeSweep(newTheme, apply);
    });
};

// Code Folding Logic
window.initCodeFold = function() {
    var codeBlocks = document.querySelectorAll('.highlight');
    codeBlocks.forEach(function(block) {
        if (block.offsetHeight > 360) {
            if (block.parentNode.classList.contains('code-fold-container')) return;

            var wrapper = document.createElement('div');
            wrapper.className = 'code-fold-container collapsed';
            block.parentNode.insertBefore(wrapper, block);
            wrapper.appendChild(block);

            var btn = document.createElement('button');
            btn.className = 'code-expand-btn';
            btn.innerHTML = '<span><i class="ri-arrow-down-s-line" style="margin-right:4px;"></i> 展开代码 </span>';
            btn.onclick = function() {
                wrapper.classList.remove('collapsed');
                btn.style.display = 'none';
            };
            wrapper.appendChild(btn);
        }
    });
};

// Code Copy Logic
window.initCodeCopy = function() {
    var codeBlocks = document.querySelectorAll('pre');

    codeBlocks.forEach(function(pre) {
        if (pre.parentNode.querySelector('.copy-code-btn')) return;
        if (pre.querySelector('.copy-code-btn')) return;

        var btn = document.createElement('button');
        btn.className = 'copy-code-btn';
        btn.innerHTML = '<i class="ri-file-copy-line"></i>';
        btn.title = "复制代码";
        btn.style.cssText =
            'position:absolute;top:-6px;right:5px;background:transparent;border:none;' +
            'color:#888;cursor:pointer;padding:5px;border-radius:4px;' +
            'transition:all 0.2s;opacity:0;z-index:10;';

        pre.addEventListener('mouseenter', function() { btn.style.opacity = '1'; });
        pre.addEventListener('mouseleave', function() { btn.style.opacity = '0'; });

        if (window.isMobile()) { btn.style.opacity = '1'; }

        btn.addEventListener('click', function(e) {
            e.stopPropagation();
            var code = pre.querySelector('code') ? pre.querySelector('code').innerText : pre.innerText;

            if (navigator.clipboard) {
                navigator.clipboard.writeText(code).then(function() {
                    window.showToast('代码已复制 / Copied!', 'success');
                    btn.innerHTML = '<i class="ri-check-line"></i>';
                    setTimeout(function() { btn.innerHTML = '<i class="ri-file-copy-line"></i>'; }, 2000);
                }).catch(function() {
                    window.showToast('复制失败 / Failed', 'error');
                });
            } else {
                var textarea = document.createElement('textarea');
                textarea.value = code;
                document.body.appendChild(textarea);
                textarea.select();
                document.execCommand('copy');
                document.body.removeChild(textarea);
                window.showToast('代码已复制 / Copied!', 'success');
            }
        });

        if (getComputedStyle(pre).position === 'static') {
            pre.style.position = 'relative';
        }

        pre.appendChild(btn);
    });
};