/* 全局样式定义 */
body {
    margin: 0;
    font-family: 'Roboto', Arial, sans-serif;
    background: linear-gradient(135deg, #f5f7fa, #e8ebf2);
    color: #333;
    line-height: 1.6;
    overflow-x: hidden;
}
h1, h2, h3, h4, h5, h6 {
    font-weight: bold;
    color: #2c3e50;
    text-align: center;
}
p, li {
    font-size: 1rem;
    color: #555;
}
a {
    text-decoration: none;
    color: #007BFF;
}
a:hover {
    text-decoration: underline;
}
.container {
    max-width: 1440px;
    margin: 0 auto;
    padding: 20px;
    display: grid;
    gap: 20px;
}
.header {
    background: linear-gradient(90deg, #1e3c72, #2a5298);
    color: white;
    padding: 40px 20px;
    text-align: center;
    border-bottom: 2px solid #152c5b;
}
.header h1 {
    font-size: 2.5rem;
    margin: 0;
}
.header p {
    font-size: 1.2rem;
    margin-top: 10px;
    color: #dce7f3;
}
.navbar {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 20px;
    background: rgba(255, 255, 255, 0.8);
    padding: 10px;
    position: sticky;
    top: 0;
    z-index: 1000;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
}
.navbar a {
    padding: 10px 20px;
    border-radius: 5px;
    transition: background-color 0.3s ease;
}
.navbar a:hover {
    background: #007BFF;
    color: white;
}
.grid-section {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 20px;
    align-items: stretch;
}
.card {
    background: white;
    border-radius: 10px;
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);
    overflow: hidden;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    padding: 20px;
    text-align: center;
}
.card:hover {
    transform: translateY(-5px);
    box-shadow: 0 6px 12px rgba(0, 0, 0, 0.15);
}
.card img {
    max-width: 100%;
    height: auto;
    border-radius: 5px;
}
.content-area {
    background: white;
    padding: 30px;
    border-radius: 10px;
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);
    margin-top: 20px;
}
.content-area h2 {
    color: #2c3e50;
    margin-bottom: 20px;
}
.content-area p, .content-area li {
    font-size: 1rem;
    line-height: 1.8;
    color: #555;
}
.code-block {
    background: #282c34;
    color: #abb2bf;
    padding: 15px;
    border-radius: 5px;
    font-family: 'Courier New', Courier, monospace;
    font-size: 0.9rem;
    overflow-x: auto;
    margin: 10px 0;
}
.button {
    display: inline-block;
    background: #28A745;
    color: white;
    padding: 10px 20px;
    border-radius: 5px;
    font-size: 1rem;
    transition: background-color 0.3s ease;
}
.button:hover {
    background: #218838;
}
.cta-button {
    background: #FFC107;
    color: black;
    font-weight: bold;
    padding: 12px 24px;
    border-radius: 5px;
    font-size: 1.1rem;
}
@media (max-width: 768px) {
    .header h1 {
        font-size: 2rem;
    }
    .navbar {
        flex-direction: column;
        gap: 10px;
    }
    .grid-section {
        grid-template-columns: 1fr;
    }
}
@media (min-width: 1200px) {
    .container {
        grid-template-columns: 1fr 2fr;
        gap: 30px;
    }
}