.course-container {
    display: flex;
    gap: 20px;
    padding: 20px;
    min-height: calc(100vh - 200px);
}

.course-sidebar {
    width: 250px;
    background: white;
    border-radius: 8px;
    padding: 20px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.course-item {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 15px;
    border-radius: 6px;
    cursor: pointer;
    transition: all 0.3s ease;
}

.course-item:hover {
    background-color: var(--secondary-color);
}

.course-item.active {
    background-color: var(--primary-color);
    color: white;
}

.course-logo {
    width: 30px;
    height: 30px;
    object-fit: contain;
}

.add-more {
    border: 2px dashed var(--border-color);
    background: transparent;
    color: #666;
    display: flex;
    align-items: center;
    gap: 10px;
    cursor: pointer;
    transition: all 0.3s ease;
}

.add-more:hover {
    border-color: var(--primary-color);
    color: var(--primary-color);
}

.add-more i {
    font-size: 16px;
}

/* 图标选择器样式 */
.icon-selector {
    display: flex;
    align-items: center;
    gap: 15px;
}

.selected-icon {
    width: 60px;
    height: 60px;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    overflow: hidden;
    display: flex;
    align-items: center;
    justify-content: center;
}

.selected-icon img {
    width: 100%;
    height: 100%;
    object-fit: contain;
}

#courseIcon {
    display: none;
}

/* 表单样式增强 */
.form-group textarea {
    width: 100%;
    padding: 8px;
    border: 1px solid var(--border-color);
    border-radius: 4px;
    resize: vertical;
    font-family: inherit;
}

.course-content {
    flex: 1;
    background: white;
    border-radius: 8px;
    padding: 30px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.course-chapters {
    display: none;
}

.course-chapters.active {
    display: block;
}

.course-chapters h2 {
    margin: 0 0 30px 0;
    color: var(--text-color);
    font-size: 24px;
}

.chapter {
    margin-bottom: 20px;
    padding: 15px;
    border: 1px solid var(--border-color);
    border-radius: 6px;
    transition: all 0.3s ease;
}

.chapter:hover {
    box-shadow: 0 2px 8px rgba(0,0,0,0.1);
}

.chapter h3 {
    margin: 0 0 10px 0;
    color: var(--text-color);
    font-size: 18px;
}

.chapter-content {
    color: #666;
    font-size: 14px;
    line-height: 1.6;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .course-container {
        flex-direction: column;
    }

    .course-sidebar {
        width: 100%;
    }
}

.course-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 30px;
}

.edit-btn {
    padding: 8px 20px;
    background-color: transparent;
    border: 1px solid var(--primary-color);
    color: var(--primary-color);
    border-radius: 4px;
    cursor: pointer;
    transition: all 0.3s ease;
    font-size: 14px;
}

.edit-btn:hover {
    background-color: var(--primary-color);
    color: white;
}

.edit-btn.active {
    background-color: var(--primary-color);
    color: white;
}

.editable {
    border: 1px dashed #ccc;
    padding: 5px;
    border-radius: 4px;
    background-color: rgba(74, 144, 226, 0.05);
}

.editable:hover {
    border-color: var(--primary-color);
}

.editable:focus {
    outline: none;
    border-color: var(--primary-color);
    background-color: white;
}

.chapter-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 10px;
}

.chapter-actions {
    display: flex;
    visibility: hidden;
    opacity: 0;
    transition: all 0.3s ease;
}

.delete-btn {
    padding: 4px 12px;
    background-color: #ff4d4f;
    color: white;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    font-size: 12px;
    transition: all 0.3s ease;
}

.delete-btn:hover {
    background-color: #ff7875;
}

.add-chapter {
    margin-top: 20px;
    display: none;
}

.add-chapter button {
    width: 100%;
    padding: 15px;
    background-color: transparent;
    border: 2px dashed var(--border-color);
    color: var(--primary-color);
    border-radius: 6px;
    cursor: pointer;
    font-size: 14px;
    transition: all 0.3s ease;
}

.add-chapter button:hover {
    background-color: var(--secondary-color);
    border-color: var(--primary-color);
}

/* 编辑模式样式 */
.course-chapters.edit-mode .chapter-actions {
    visibility: visible;
    opacity: 1;
}

.course-chapters.edit-mode .add-chapter {
    display: block;
}