// 主题切换器
class ThemeSwitcher {
    constructor() {
        this.currentTheme = localStorage.getItem('theme') || 'light';
        this.init();
    }

    init() {
        this.applyTheme(this.currentTheme);
        this.createThemeToggle();
        this.setupSystemThemeListener();
    }

    applyTheme(theme) {
        const root = document.documentElement;
        
        if (theme === 'dark') {
            root.classList.add('dark-theme');
            root.classList.remove('light-theme');
        } else {
            root.classList.add('light-theme');
            root.classList.remove('dark-theme');
        }
        
        this.currentTheme = theme;
        localStorage.setItem('theme', theme);
        this.updateToggleIcon();
    }

    createThemeToggle() {
        const toggle = document.createElement('button');
        toggle.className = 'theme-toggle';
        toggle.innerHTML = this.getThemeIcon();
        toggle.setAttribute('aria-label', '切换主题');
        
        toggle.style.cssText = `
            position: fixed;
            top: 1rem;
            right: 1rem;
            z-index: 1000;
            background: rgba(255, 255, 255, 0.9);
            border: 2px solid var(--border);
            border-radius: 50%;
            width: 48px;
            height: 48px;
            cursor: pointer;
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 1.2rem;
            box-shadow: var(--shadow-md);
            transition: all var(--transition-normal);
        `;
        
        toggle.addEventListener('click', () => this.toggleTheme());
        document.body.appendChild(toggle);
        
        // 悬停效果
        toggle.addEventListener('mouseenter', () => {
            toggle.style.transform = 'scale(1.1)';
            toggle.style.boxShadow = 'var(--shadow-lg)';
        });
        
        toggle.addEventListener('mouseleave', () => {
            toggle.style.transform = 'scale(1)';
            toggle.style.boxShadow = 'var(--shadow-md)';
        });
    }

    getThemeIcon() {
        return this.currentTheme === 'dark' ? '🌙' : '☀️';
    }

    updateToggleIcon() {
        const toggle = document.querySelector('.theme-toggle');
        if (toggle) {
            toggle.innerHTML = this.getThemeIcon();
        }
    }

    toggleTheme() {
        const newTheme = this.currentTheme === 'dark' ? 'light' : 'dark';
        this.applyTheme(newTheme);
    }

    setupSystemThemeListener() {
        const mediaQuery = window.matchMedia('(prefers-color-scheme: dark)');
        
        mediaQuery.addEventListener('change', (e) => {
            if (!localStorage.getItem('theme')) {
                this.applyTheme(e.matches ? 'dark' : 'light');
            }
        });
    }
}

// 初始化主题切换器
document.addEventListener('DOMContentLoaded', () => {
    new ThemeSwitcher();
});

// 添加页面加载动画
window.addEventListener('load', () => {
    document.body.classList.add('loaded');
});