eLearning Solution with Codeigniter

In the backend an admin can configure some courses. A course consists of some slides, which have usually an image and some text below. Each course includes a test of a few multiple choice questions. Each question consists of an image, a text-question and multiple-choice questions. So like I described, the data logic is that we have courses, which consists of training-slides and tests and which can only be created and edited by an admin. Other user roles under the admin are company-principal and employee. Each employee has one or more company-principals. An admin can assign courses to company-principals. They can assign the courses to each of THEIR employees. A company-principal can see which employee has finished which course in a filterable datagrid. An employee can login an see which courses he has to do and which courses he has finished. A course is only finsihed, if all test questions are answered correctly. For a finished course an employee can download a PDF certificate. We cannot provide a design but you can just choose any standard bootstrap, foundation or other clear and flat design for it. Just make sure that the colors and typography may be adjusted so please use SASS / SCSS or LESS with variables for colors, fonts and standard margins.