/* 全局样式与色彩渐变定义 */
body {
    margin: 0;
    font-family: 'Poppins', sans-serif;
    background: linear-gradient(135deg, #f5f7fa, #c3cfe2);
    color: #333;
    line-height: 1.6;
    overflow-x: hidden;
}
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 20px;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 20px;
}
h1, h2, h3, h4 {
    font-weight: bold;
    color: #2c3e50;
    text-align: center;
}
h1 {
    font-size: 2.5rem;
    margin-bottom: 20px;
}
h2 {
    font-size: 2rem;
    margin-top: 30px;
    margin-bottom: 15px;
}
h3 {
    font-size: 1.75rem;
    margin-top: 25px;
    margin-bottom: 10px;
}
h4 {
    font-size: 1.5rem;
    margin-top: 20px;
    margin-bottom: 10px;
}
p {
    font-size: 1rem;
    margin-bottom: 15px;
    text-align: justify;
}
a {
    color: #007acc;
    text-decoration: none;
    transition: color 0.3s ease;
}
a:hover {
    color: #ff9800;
}
code {
    font-family: 'Courier New', monospace;
    background-color: #f0f0f0;
    padding: 2px 5px;
    border-radius: 4px;
    font-size: 0.9rem;
}
pre {
    background-color: #2c3e50;
    color: #ecf0f1;
    padding: 15px;
    border-radius: 8px;
    overflow-x: auto;
}
table {
    width: 100%;
    border-collapse: collapse;
    margin: 20px 0;
}
th, td {
    border: 1px solid #ddd;
    padding: 10px;
    text-align: left;
}
th {
    background-color: #007acc;
    color: white;
}
td {
    background-color: #f9f9f9;
}
img {
    max-width: 100%;
    height: auto;
    border-radius: 8px;
    margin-bottom: 15px;
}
button {
    background-color: #007acc;
    color: white;
    border: none;
    padding: 10px 20px;
    cursor: pointer;
    transition: background-color 0.3s ease;
    border-radius: 5px;
}
button:hover {
    background-color: #ff9800;
}
.line-art {
    width: 100px;
    height: 100px;
    border: 2px solid #007acc;
    border-radius: 50%;
    position: relative;
    margin: 20px auto;
}
.line-art::before,
.line-art::after {
    content: '';
    position: absolute;
    width: 50px;
    height: 50px;
    background: #007acc;
    border-radius: 50%;
}
.line-art::before {
    top: -25px;
    left: -25px;
}
.line-art::after {
    bottom: -25px;
    right: -25px;
}
.loader {
    width: 50px;
    height: 50px;
    border: 5px solid #007acc;
    border-top-color: transparent;
    border-radius: 50%;
    animation: rotate 1s linear infinite;
    margin: 20px auto;
}
@keyframes rotate {
    from {
        transform: rotate(0deg);
    }
    to {
        transform: rotate(360deg);
    }
}
@media (max-width: 768px) {
    .container {
        grid-template-columns: 1fr;
    }
    h1 {
        font-size: 2rem;
    }
    h2 {
        font-size: 1.75rem;
    }
    pre {
        font-size: 0.8rem;
    }
}