body {
    background: #f5f5f5;
}

.login-container {
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
}

.login-box {
    background: white;
    padding: 40px;
    border-radius: 8px;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
    width: 100%;
    max-width: 400px;
}

.sidebar {
    background: #343a40;
    min-height: calc(100vh - 56px);
    padding: 20px 0;
}

.sidebar .nav-link {
    color: #fff;
    padding: 12px 20px;
    border-radius: 0;
}

.sidebar .nav-link:hover {
    background: rgba(255, 255, 255, 0.1);
}

.sidebar .nav-link.active {
    background: #007bff;
}

.main-content {
    padding: 20px;
}

.page-content {
    background: white;
    padding: 30px;
    border-radius: 8px;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

.preview-img {
    max-width: 200px;
    max-height: 200px;
    border: 1px solid #ddd;
    border-radius: 4px;
    padding: 5px;
    background: #fff;
    object-fit: contain;
    max-width: 200px;
    max-height: 100px;
    border: 1px solid #ddd;
    border-radius: 4px;
}

.table {
    background: white;
}

/* Markdown编辑器样式（textarea） */
textarea[name="content"],
textarea[name="markdown_content"],
#newsContentEditor,
#businessMarkdownContent,
#subjectMarkdownContent,
#moduleMarkdownContent {
    min-height: 400px;
    font-family: 'Consolas', 'Monaco', 'Courier New', monospace;
    font-size: 14px;
    line-height: 1.6;
    padding: 12px;
    border: 1px solid #ddd;
    border-radius: 4px;
    resize: vertical;
    width: 100%;
}

textarea[name="content"]:focus,
textarea[name="markdown_content"]:focus,
#newsContentEditor:focus,
#businessMarkdownContent:focus,
#subjectMarkdownContent:focus,
#moduleMarkdownContent:focus {
    border-color: #007bff;
    outline: none;
    box-shadow: 0 0 0 0.2rem rgba(0, 123, 255, 0.25);
}