/* Style accordion's visible panels (buttons) */
            .semester {
                background-color: #4B0082;
                color: #FFF;
                cursor: pointer;
                padding: 11px;
                width: 100%;
                border-width: 3px;
                border-color: #FFF;
                border-style: outset;
                text-align: center;
                outline: none;
                font-size: 27px;
                transition: 0.4s;
                text-transform: uppercase;
            }

            /* Text centre alignment */
            p {
                text-align: center;
            }

            /* When hovering, change background color */
            .active,
            .semester:hover {
                background-color: #BA55D3;
            }

            /* Style invisible panel, panel that you see after clicking on visible accordion's panels */
            .courses {
                padding: 0 18px;
                background-color: white;
                max-height: 0;
                overflow: hidden;
                transition: max-height 0.2s ease-out;
                margin: auto;
            }

            /* Accordion's centre alignment */
            .semester {
                margin: 0 auto;
            }

            .semester-container {
                width: 65%;
                margin: auto;
            }

            ol {
                width: 45%;
                margin: auto;
            }

            h1 {
                text-align: center;
            }

            /* Style accordion's + - buttons  */
            .semester:after {
                content: '\002B';
                color: #FFF;
                font-weight: bold;
                float: right;
                margin-left: 5px;
            }

            .active:after {
                content: "\2212";

            }

            /* Style courses' list */
            ol li {
                font-family: sans-serif;
                padding: 5px;
                color: #111;
            }