/* 全局样式 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

/* CSS变量定义 */
:root {
    /* 浅色主题颜色 */
    --bg-color: #f5f5f5;
    --text-color: #333;
    --header-bg: #fff;
    --main-bg: #fff;
    --card-bg: #fff;
    --card-hover-bg: #f8f9fa;
    --border-color: #ddd;
    --shadow-color: rgba(0,0,0,0.1);
    --primary-color: #3498db;
    --success-color: #27ae60;
    --warning-color: #f39c12;
    --danger-color: #e74c3c;
    --link-color: #3498db;
    --link-hover-color: #2980b9;
    --footer-bg: #2c3e50;
    --footer-text: white;
    --input-bg: #fff;
    --input-border: #ddd;
    --input-focus: #3498db;
    --dropdown-bg: #f9f9f9;
    --dropdown-hover: #f1f1f1;
}

/* 深色主题颜色 */
[data-theme="dark"] {
    --bg-color: #1a1a1a;
    --text-color: #e0e0e0;
    --header-bg: #2d2d2d;
    --main-bg: #2d2d2d;
    --card-bg: #333;
    --card-hover-bg: #444;
    --border-color: #555;
    --shadow-color: rgba(0,0,0,0.3);
    --primary-color: #5dade2;
    --success-color: #58d68d;
    --warning-color: #f7dc6f;
    --danger-color: #ec7063;
    --link-color: #5dade2;
    --link-hover-color: #85c1e9;
    --footer-bg: #1e1e1e;
    --footer-text: #e0e0e0;
    --input-bg: #444;
    --input-border: #555;
    --input-focus: #5dade2;
    --dropdown-bg: #333;
    --dropdown-hover: #444;
}

/* 全局应用颜色变量 */
body {
    background-color: var(--bg-color);
    color: var(--text-color);
    font-family: 'Arial', 'Microsoft YaHei', sans-serif;
    line-height: 1.6;
    transition: background-color 0.3s, color 0.3s;
}

body {
    font-family: 'Microsoft YaHei', 'SimSun', Arial, sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--bg-color);
    transition: background-color 0.3s, color 0.3s;
}

/* 头部导航 */
header {
    background-color: var(--header-bg);
    box-shadow: 0 2px 5px var(--shadow-color);
    position: sticky;
    top: 0;
    z-index: 100;
}

nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    max-width: 1200px;
    margin: 0 auto;
    padding: 1rem 2rem;
}

.logo {
    font-size: 1.5rem;
    font-weight: bold;
    color: var(--primary-color);
}

.nav-links {
    display: flex;
    list-style: none;
}

/* 下拉菜单样式 */
.dropdown {
    position: relative;
    display: inline-block;
}

.dropdown-content {
    display: none;
    position: absolute;
    background-color: #f9f9f9;
    min-width: 160px;
    box-shadow: 0px 8px 16px 0px rgba(0,0,0,0.2);
    z-index: 1;
    border-radius: 4px;
    overflow: hidden;
}

.dropdown-content a {
    color: black;
    padding: 12px 16px;
    text-decoration: none;
    display: block;
}

.dropdown-content a:hover {
    background-color: #f1f1f1;
}

.dropdown:hover .dropdown-content {
    display: block;
}

.dropdown:hover .dropbtn {
    background-color: #f1f1f1;
}

.dropbtn {
    color: #333;
    font-weight: 500;
    transition: background-color 0.3s;
}

.nav-links li {
    margin-left: 1.5rem;
}

.nav-links a {
    text-decoration: none;
    color: var(--text-color);
    font-weight: 500;
    transition: color 0.3s;
}

.nav-links a:hover {
    color: var(--link-hover-color);
}

/* 主要内容区域 */
main {
    max-width: 1200px;
    margin: 2rem auto;
    padding: 0 2rem;
    background-color: var(--main-bg);
    border-radius: 8px;
    box-shadow: 0 2px 10px var(--shadow-color);
}

/* 英雄区域 */
.hero {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    text-align: center;
    padding: 4rem 2rem;
    border-radius: 8px 8px 0 0;
}

/* 深色模式下的英雄区域 */
[data-theme="dark"] .hero {
    background: linear-gradient(135deg, #4a5eb3 0%, #5a3a8a 100%);
}

.hero h1 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

.hero p {
    font-size: 1.2rem;
    opacity: 0.9;
}

/* 内容区域 */
.content {
    padding: 3rem 2rem;
}

.content h2 {
    font-size: 2rem;
    margin-bottom: 1.5rem;
    color: var(--text-color);
    text-align: center;
}

/* 工具网格 */
.tools-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2rem;
    margin-top: 2rem;
}

/* 确保首页工具网格显示四列 */
.content .tools-grid {
    grid-template-columns: repeat(4, 1fr);
}

@media (max-width: 1200px) {
    .content .tools-grid {
        grid-template-columns: repeat(3, 1fr);
    }
}

@media (max-width: 900px) {
    .content .tools-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 600px) {
    .content .tools-grid {
        grid-template-columns: 1fr;
    }
}

.tool-card {
    background: var(--card-bg);
    padding: 2rem;
    border-radius: 8px;
    box-shadow: 0 2px 10px var(--shadow-color);
    text-align: center;
    transition: transform 0.3s, box-shadow 0.3s;
}

/* 分类卡片样式 */
.categories-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-top: 2rem;
}

.category-card {
    background: var(--card-bg);
    padding: 2rem;
    border-radius: 8px;
    box-shadow: 0 2px 10px var(--shadow-color);
}

.category-card h3 {
    color: var(--text-color);
    margin-bottom: 1.5rem;
    font-size: 1.5rem;
    text-align: center;
}

.category-tools {
    margin-bottom: 1.5rem;
}

.category-tool-item {
    margin-bottom: 1rem;
    padding-bottom: 1rem;
    border-bottom: 1px solid var(--border-color);
}

.category-tool-item:last-child {
    border-bottom: none;
    margin-bottom: 0;
    padding-bottom: 0;
}

.category-tool-item a {
    display: block;
    color: var(--link-color);
    font-weight: 500;
    margin-bottom: 0.5rem;
    text-decoration: none;
}

.category-tool-item a:hover {
    color: var(--link-hover-color);
}

.tool-desc {
    color: var(--text-color);
    font-size: 0.9rem;
}

.view-all-btn {
    display: block;
    text-align: center;
    background-color: var(--primary-color);
    color: white;
    padding: 0.8rem;
    border-radius: 4px;
    text-decoration: none;
    transition: background-color 0.3s;
}

.view-all-btn:hover {
    background-color: var(--primary-color);
    color: white;
}

.tool-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 5px 20px var(--shadow-color);
}

/* 工具网格 - 确保首页工具网格显示四列 */
.content .tools-grid {
    grid-template-columns: repeat(4, 1fr);
}

@media (max-width: 1200px) {
    .content .tools-grid {
        grid-template-columns: repeat(3, 1fr);
    }
}

@media (max-width: 900px) {
    .content .tools-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 600px) {
    .content .tools-grid {
        grid-template-columns: 1fr;
    }
}

.tool-card {
    background: #fff;
    padding: 2rem;
    border-radius: 8px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
    text-align: center;
    transition: transform 0.3s, box-shadow 0.3s;
    text-decoration: none;
    color: inherit;
}

.tool-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 5px 20px var(--shadow-color);
}

.tool-card h3 {
    color: var(--text-color);
    margin-bottom: 1rem;
    font-size: 1.4rem;
}

.tool-card p {
    color: var(--text-color);
    margin-bottom: 1.5rem;
    line-height: 1.6;
}

/* 特性部分 */
.features {
    padding: 60px 0;
}

.feature-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 30px;
    margin-top: 30px;
}

.feature-item {
    text-align: center;
    padding: 30px;
    border-radius: 8px;
    background: var(--card-bg);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.feature-item:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 25px rgba(0,0,0,0.1);
}

.feature-item h3 {
    color: var(--text-color);
    margin-bottom: 15px;
    font-size: 1.3rem;
}

/* 工具部分 */
.tools {
    padding: 60px 0;
    background-color: var(--bg-color);
}

.tools h2 {
    text-align: center;
    margin-bottom: 40px;
}

/* 内容部分 */
.content-section {
    padding: 60px 0;
}

.content-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
    margin-top: 30px;
}

.content-item {
    padding: 25px;
    border-radius: 8px;
    background: var(--card-bg);
}

.content-item h3 {
    color: var(--text-color);
    margin-bottom: 15px;
}

/* FAQ部分 */
.faq-section {
    padding: 60px 0;
    background-color: var(--bg-color);
}

.faq-content {
    max-width: 800px;
    margin: 0 auto;
}

.faq-item {
    background: var(--card-bg);
    margin-bottom: 15px;
    border-radius: 8px;
    overflow: hidden;
    box-shadow: 0 2px 10px var(--shadow-color);
}

.faq-item h3 {
    margin: 0;
    padding: 20px;
    background: var(--primary-color);
    color: white;
    font-size: 1.1rem;
}

.faq-item p {
    padding: 20px;
    margin: 0;
    color: var(--text-color);
}

.tool-card h3 {
    color: var(--text-color);
    margin-bottom: 1rem;
    font-size: 1.4rem;
}

.tool-card p {
    color: #7f8c8d;
    margin-bottom: 1.5rem;
    line-height: 1.6;
}

/* 响应式设计 */
@media (max-width: 768px) {
    nav {
        flex-direction: column;
        padding: 1rem;
    }
    
    .nav-links {
        flex-wrap: wrap;
        justify-content: center;
    }
    
    .nav-links li {
        margin: 0.5rem;
    }
    
    .hero h1 {
        font-size: 2rem;
    }
    
    .content, .tool-container, .about-content {
        padding: 2rem 1rem;
    }
    
    .tools-grid {
        grid-template-columns: 1fr;
    }
    
    .action-buttons {
        flex-direction: column;
    }
    
    .categories-grid {
        grid-template-columns: 1fr;
    }
    
    .dropdown-content {
        left: auto;
        right: 0;
    }
}

.btn {
    background-color: var(--primary-color);
    color: white;
    padding: 0.8rem 1.5rem;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    font-size: 1rem;
    transition: background-color 0.3s;
    text-decoration: none;
    display: inline-block;
}

.btn:hover {
    background-color: var(--primary-color);
}

/* 工具页面样式 */
.tool-container {
    padding: 3rem 2rem;
}

.tool-header {
    text-align: center;
    margin-bottom: 2rem;
}

.tool-header h1 {
    font-size: 2.5rem;
    color: #2c3e50;
    margin-bottom: 1rem;
}

.tool-header p {
    color: #7f8c8d;
    font-size: 1.1rem;
}

.tool-section {
    background: var(--card-bg);
    padding: 2rem;
    border-radius: 8px;
    margin-bottom: 2rem;
}

.input-area, .output-area {
    margin-bottom: 1.5rem;
}

.input-area label, .output-area label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 500;
    color: #2c3e50;
}

.textarea {
    width: 100%;
    padding: 1rem;
    border: 1px solid var(--border-color);
    border-radius: 4px;
    font-size: 1rem;
    font-family: 'Courier New', monospace;
    resize: vertical;
    min-height: 150px;
    background-color: var(--input-bg);
    color: var(--text-color);
}

/* 输入框样式 */
input[type="text"].textarea {
    min-height: auto;
    padding: 0.8rem;
    font-family: Arial, sans-serif;
}

.action-buttons {
    display: flex;
    gap: 1rem;
    margin-top: 1rem;
}

.action-btn {
    background-color: var(--success-color);
    color: white;
    padding: 0.8rem 1.5rem;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    font-size: 1rem;
    transition: background-color 0.3s;
}

.action-btn:hover {
    background-color: var(--success-color);
}

.clear-btn {
    background-color: var(--danger-color);
}

.clear-btn:hover {
    background-color: var(--danger-color);
}

.copy-btn {
    background-color: var(--primary-color);
}

.copy-btn:hover {
    background-color: var(--primary-color);
}

/* 文章样式 (用于新闻资讯) */
.article {
    margin-bottom: 2rem;
    padding-bottom: 2rem;
    border-bottom: 1px solid #eee;
}

.article:last-child {
    border-bottom: none;
}

.article h3 {
    color: #2c3e50;
    margin-bottom: 1rem;
}

.article p {
    text-align: left;
    margin-bottom: 1rem;
    color: #555;
}

.date {
    color: #7f8c8d;
    font-size: 0.9rem;
    margin-bottom: 1rem;
}

/* 关于我们页面样式 */
.about-content {
    padding: 3rem 2rem;
}

.about-content h2 {
    font-size: 2rem;
    margin-bottom: 1.5rem;
    color: #2c3e50;
    text-align: center;
}

/* 页脚 */
footer {
    text-align: center;
    padding: 2rem;
    background-color: var(--footer-bg);
    color: var(--footer-text);
    margin-top: 3rem;
}

/* 表单样式 */
.contact-form {
    max-width: 600px;
    margin: 0 auto;
}

.form-group {
    margin-bottom: 1.5rem;
}

.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    color: #2c3e50;
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 0.8rem;
    border: 1px solid #ddd;
    border-radius: 4px;
    font-size: 1rem;
}

.form-group textarea {
    height: 150px;
    resize: vertical;
}

/* 广告样式 */
.ad-footer {
    padding: 1rem;
    text-align: center;
    background-color: #f8f9fa;
    margin-top: 2rem;
}

/* 响应式设计 */
@media (max-width: 768px) {
    nav {
        flex-direction: column;
        padding: 1rem;
    }
    
    .nav-links {
        margin-top: 1rem;
    }
    
    .nav-links li {
        margin: 0 1rem;
    }
    
    .hero h1 {
        font-size: 2rem;
    }
    
    .content, .tool-container, .about-content {
        padding: 2rem 1rem;
    }
    
    .tools-grid {
        grid-template-columns: 1fr;
    }
    
    .tool-section {
        padding: 1.5rem;
    }
    
    .action-buttons {
        flex-direction: column;
    }
}