/* General Body Styles */
body {
    font-family: 'Arial', 'Microsoft YaHei', sans-serif;
    line-height: 1.6;
    color: #333;
    background-color: #f8fafc;
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Header & Navigation */
header {
    background: #1e3a8a;
    padding: 1rem 0;
    position: relative; /* Changed from fixed to relative for sub-page */
    width: 100%;
    top: 0;
    z-index: 1000;
    box-shadow: 0 2px 10px rgba(30, 58, 138, 0.1);
}

header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 1.8rem;
    font-weight: bold;
    color: white;
}

.nav-links {
    display: flex;
    list-style: none;
    gap: 2rem;
}

.nav-links a {
    color: white;
    text-decoration: none;
    font-weight: 500;
    transition: color 0.3s ease;
}

.nav-links a:hover {
    color: #60a5fa;
}

/* Main Content Section */
.main-content {
    padding: 80px 0;
    background: white;
    margin-top: 20px;
    border-radius: 12px;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
}

.main-content h2 {
    text-align: center;
    font-size: 2.5rem;
    color: #1e3a8a;
    margin-bottom: 2rem;
}

.main-content img {
    max-width: 80%;
    height: auto;
    display: block;
    margin: 20px auto;
    border-radius: 8px;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
}

.main-content p {
    margin-bottom: 1.5rem;
    color: #4b5563;
    font-size: 1.1rem;
    text-align: justify;
}

.main-content h3 {
    font-size: 1.8rem;
    color: #1e3a8a;
    margin-top: 2rem;
    margin-bottom: 1rem;
}

.main-content ul {
    list-style: disc;
    margin-left: 20px;
    margin-bottom: 1.5rem;
    color: #4b5563;
}

.main-content ul li {
    margin-bottom: 0.5rem;
}

/* Footer */
footer {
    background: #111827;
    color: white;
    padding: 2rem 0;
    text-align: center;
    margin-top: 40px;
}

footer p {
    margin: 0;
    font-size: 0.9rem;
    color: #d1d5db;
}