* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Microsoft YaHei', 'PingFang SC', 'Helvetica Neue', Arial, sans-serif;
    line-height: 1.7;
    color: #2c3e50;
    background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
    min-height: 100vh;
}

/* 整体容器 */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 20px;
}

/* 头部样式 - 专业蓝色调 */
header {
    background: linear-gradient(135deg, #3498db 0%, #2980b9 100%);
    border-radius: 12px;
    padding: 35px 0;
    text-align: center;
    margin-bottom: 30px;
    box-shadow: 0 8px 25px rgba(52, 152, 219, 0.3);
    position: relative;
    overflow: hidden;
}

header::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, #e74c3c, #3498db, #2ecc71);
}

header h1 {
    color: white;
    font-size: 2.8em;
    margin-bottom: 20px;
    font-weight: 600;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.2);
}

/* 导航栏样式 - 简洁专业 */
nav ul {
    list-style: none;
    display: flex;
    justify-content: center;
    gap: 20px;
    flex-wrap: wrap;
}

nav ul li {
    margin: 0;
}

nav a {
    color: white;
    text-decoration: none;
    font-weight: 500;
    font-size: 1.1em;
    padding: 12px 28px;
    border-radius: 8px;
    transition: all 0.3s ease;
    background: rgba(255, 255, 255, 0.15);
    border: 1px solid rgba(255, 255, 255, 0.2);
}

nav a:hover {
    background: rgba(255, 255, 255, 0.25);
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.2);
}

/* 主内容区样式 */
main {
    background: white;
    border-radius: 12px;
    padding: 40px;
    margin-bottom: 30px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.08);
    border: 1px solid #e9ecef;
}

/* 章节样式 - 专业卡片设计 */
section {
    margin-bottom: 35px;
    padding: 30px;
    background: #ffffff;
    border-radius: 10px;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.05);
    transition: all 0.3s ease;
    border-left: 4px solid #3498db;
    position: relative;
}

section:hover {
    transform: translateY(-3px);
    box-shadow: 0 6px 20px rgba(0, 0, 0, 0.1);
}

/* 标题样式 */
h2 {
    color: #2c3e50;
    font-size: 1.9em;
    margin-bottom: 20px;
    padding-bottom: 12px;
    font-weight: 600;
    position: relative;
}

h2::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 60px;
    height: 3px;
    background: linear-gradient(90deg, #3498db, #2980b9);
    border-radius: 2px;
}

h3 {
    color: #34495e;
    font-size: 1.5em;
    margin-bottom: 15px;
    font-weight: 600;
}

/* 段落样式 */
p {
    color: #555;
    font-size: 1.1em;
    margin-bottom: 18px;
    text-align: justify;
    line-height: 1.8;
}

/* 文章卡片样式 */
article {
    background: #f8f9fa;
    padding: 25px;
    margin: 20px 0;
    border-radius: 8px;
    transition: all 0.3s ease;
    border-left: 4px solid;
}

/* 为不同文章添加不同颜色 */
article:nth-child(odd) {
    border-left-color: #e74c3c;
    background: linear-gradient(135deg, #fdf2f2, #fce8e8);
}

article:nth-child(even) {
    border-left-color: #2ecc71;
    background: linear-gradient(135deg, #f2fdf2, #e8fce8);
}

article:hover {
    transform: translateX(5px);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
}

/* 图片样式 */
img {
    max-width: 100%;
    height: auto;
    border-radius: 8px;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
    transition: all 0.3s ease;
    border: 2px solid #e9ecef;
}

img:hover {
    transform: scale(1.02);
    box-shadow: 0 6px 18px rgba(0, 0, 0, 0.15);
}

/* 页脚样式 */
footer {
    background: linear-gradient(135deg, #2c3e50 0%, #34495e 100%);
    color: white;
    text-align: center;
    padding: 25px;
    border-radius: 12px;
    margin-top: 40px;
    box-shadow: 0 -5px 20px rgba(0, 0, 0, 0.1);
}

footer p {
    color: white;
    margin: 0;
    font-size: 1em;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .container {
        padding: 15px;
    }
    
    header h1 {
        font-size: 2.2em;
    }
    
    nav ul {
        flex-direction: column;
        gap: 12px;
    }
    
    nav a {
        display: block;
        text-align: center;
        padding: 15px 20px;
    }
    
    main {
        padding: 25px;
    }
    
    section {
        padding: 20px;
    }
}

/* 动画效果 */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

section, article {
    animation: fadeInUp 0.6s ease-out;
}

/* 专业特色元素 */
.accent-color-1 { color: #3498db; }
.accent-color-2 { color: #e74c3c; }
.accent-color-3 { color: #2ecc71; }

/* 引用块样式 */
blockquote {
    border-left: 4px solid #3498db;
    padding: 20px;
    margin: 25px 0;
    background: #f8f9fa;
    border-radius: 0 8px 8px 0;
    font-style: italic;
    color: #555;
}

/* 代码样式 */
code {
    background: #f4f4f4;
    padding: 3px 8px;
    border-radius: 4px;
    font-family: 'Courier New', monospace;
    color: #e74c3c;
    border: 1px solid #e9ecef;
}

/* 链接样式 */
a {
    color: #3498db;
    text-decoration: none;
    transition: color 0.3s ease;
    font-weight: 500;
}

a:hover {
    color: #2980b9;
    text-decoration: underline;
}

/* 专业标签 */
.tag {
    display: inline-block;
    padding: 4px 12px;
    background: #3498db;
    color: white;
    border-radius: 4px;
    font-size: 0.9em;
    margin-right: 8px;
    margin-bottom: 8px;
}

.tag-news { background: #e74c3c; }
.tag-writing { background: #2ecc71; }
.tag-research { background: #9b59b6; }