/* 全局样式设置 */
/* 设置页面的整体布局和响应式设计 */
body {
    margin: 0;
    padding: 0;
    font-family: 'Roboto', sans-serif; /* 使用现代无衬线字体 */
    background: linear-gradient(135deg, #1E3A8A 70%, #6EE7B7 25%, #FA5B3D 5%);
    color: #333333;
    line-height: 1.6;
}

/* 设计清晰的章节导航系统 */
.navbar {
    position: fixed;
    top: 0;
    width: 100%;
    background-color: rgba(30, 58, 138, 0.9);
    padding: 15px 30px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
    z-index: 1000;
}

.navbar ul {
    list-style: none;
    display: flex;
    justify-content: flex-end;
    margin: 0;
    padding: 0;
}

.navbar li {
    margin-left: 20px;
}

.navbar a {
    color: #FFFFFF;
    text-decoration: none;
    font-size: 16px;
    transition: color 0.3s ease;
}

.navbar a:hover {
    color: #FA5B3D;
}

/* 页面主体内容 */
.container {
    max-width: 1200px;
    margin: 100px auto 50px auto; /* 顶部留出导航栏空间 */
    padding: 0 20px;
    display: grid;
    grid-template-columns: repeat(12, 1fr);
    gap: 20px;
}

/* 独立视觉区块 */
.section {
    grid-column: span 12;
    background-color: rgba(255, 255, 255, 0.8);
    padding: 30px;
    border-radius: 10px;
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.section:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 12px rgba(0,0,0,0.2);
}

/* 标题样式 */
h2, h3, h4 {
    color: #1E3A8A;
    margin-bottom: 15px;
}

h2 {
    font-size: 24px;
    border-bottom: 2px solid #6EE7B7;
    padding-bottom: 10px;
}

h3 {
    font-size: 20px;
    margin-top: 25px;
}

h4 {
    font-size: 18px;
    margin-top: 20px;
}

/* 正文样式 */
p {
    font-size: 16px;
    margin-bottom: 15px;
    text-align: justify;
}

/* 按钮样式 */
.btn {
    display: inline-block;
    background-color: #FA5B3D;
    color: #ffffff;
    padding: 10px 20px;
    border: none;
    border-radius: 5px;
    text-decoration: none;
    font-size: 16px;
    transition: background-color 0.3s ease;
}

.btn:hover {
    background-color: #FF7F50;
}

/* 图片样式 */
img {
    width: 100%;
    border-radius: 10px;
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

img:hover {
    transform: scale(1.05);
    box-shadow: 0 8px 12px rgba(0,0,0,0.2);
}

/* 代码块样式 */
pre {
    background-color: #F3F4F6;
    padding: 15px;
    border-radius: 5px;
    overflow-x: auto;
    margin-bottom: 20px;
}

code {
    font-family: 'Courier New', Courier, monospace;
    color: #1E3A8A;
}

/* 导航链接样式 */
.nav-links {
    margin-bottom: 30px;
}

.nav-links a {
    display: inline-block;
    margin-right: 15px;
    color: #6EE7B7;
    text-decoration: none;
    font-size: 16px;
    transition: color 0.3s ease;
}

.nav-links a:hover {
    color: #FA5B3D;
}

/* 提示信息样式 */
.prompt {
    background-color: rgba(250, 91, 61, 0.1);
    padding: 20px;
    border-left: 5px solid #FA5B3D;
    margin-bottom: 30px;
    font-size: 18px;
    color: #1E3A8A;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .container {
        grid-template-columns: repeat(6, 1fr);
    }
    .section {
        grid-column: span 6;
    }
}

@media (max-width: 480px) {
    .navbar ul {
        flex-direction: column;
        align-items: flex-start;
    }
    .navbar li {
        margin-left: 0;
        margin-bottom: 10px;
    }
    .container {
        grid-template-columns: 1fr;
    }
    .section {
        grid-column: span 1;
    }
}

/* 动画效果 */
@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

.fade-in {
    animation: fadeIn 2s ease-in-out;
}

/* 高级CSS3特性应用 */
.background-gradient {
    background: linear-gradient(135deg, #1E3A8A, #6EE7B7);
    background-size: 400% 400%;
    animation: gradientAnimation 15s ease infinite;
}

@keyframes gradientAnimation {
    0% { background-position: 0% 50%; }
    50% { background-position: 100% 50%; }
    100% { background-position: 0% 50%; }
}

.shadow-box {
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
    border-radius: 10px;
}

.transition-effect {
    transition: all 0.3s ease;
}

.hover-scale:hover {
    transform: scale(1.05);
}

.border-decor {
    border-top: 2px solid #6EE7B7;
    margin: 20px 0;
}

.decorative-line {
    height: 2px;
    background: linear-gradient(to right, #1E3A8A, #6EE7B7);
    margin: 30px 0;
}

.button-transition {
    transition: background-color 0.3s ease, color 0.3s ease;
}

.button-transition:hover {
    background-color: #FF7F50;
    color: #ffffff;
}