body {
    background-image: url('black.jpg');
    background-position: center;
    background-repeat: no-repeat;
    background-attachment: fixed;
    background-size: cover;
    font-family: 'Montserrat';
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    height: 97.4vh;
}

.centerFit {
    width: 50%;
    height: fit-content;
    background-image: linear-gradient(#234583b6, #72ff7a70);
    border-radius: 10px;
    padding: 25px;
    animation: fadeInAnimation ease 1s;
    animation-iteration-count: 1;
    animation-fill-mode: forwards;
}

.centerFitNoHW {
    background-image: linear-gradient(#234583b6, #72ff7a70);
    border-radius: 10px;
    padding: 25px;
    width: 92%;
    height: 80%;
    margin: 0px;
    display: flex;
    animation: fadeInAnimation ease 1s;
    animation-iteration-count: 1;
    animation-fill-mode: forwards;
}

@keyframes fadeInAnimation {
    0% {
        opacity: 0;
    }

    100% {
        opacity: 1;
    }
}

.center {
    display: flex;
    align-items: center;
    justify-content: center;
}

button {
    background-color: #6179ff;
    border-color: #6179ff;
    color: black;
    border-radius: 16px;
    padding-left: 16px;
    padding-right: 16px;
    padding-top: 12px;
    padding-bottom: 12px;
    border-style: solid;
    font-family: 'Montserrat';
    font-weight: bold;
    font-size: 14px;
    width: 200px;
    transition-duration: 0.4s;
}

button:hover {
    color: white;
    background-color: black;
    border-color: #6179ff;
}

.start {
    background-color: #49ff8f;
    border-color: #49ff8f;
}

.start:hover {
    color: white;
    background-color: black;
    border-color: #49ff8f;
}

img {
    opacity: 1;
    transition-duration: 0.5s;
}

img:hover {
    opacity: 0.5;
}

.topicList {
    overflow: auto;
    width: 250px;
    flex-grow: 1;
    background-color: #72ff79;
    border-radius: 14px;
    padding: 10px;
}

.topicListItem {
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
    border-radius: 12px;
    padding-top: 10px;
    margin-bottom: 10px;
    height: 100px;
    width: 100%;
}

.topicDataDiv {
    height: 200px;
    width: 98%;
    padding: 12px;
    background-color: #234583;
    border-radius: 12px;
    overflow: auto;
}

#learnDivParent {
    height: 88.3%;
    flex-grow: 1;
    margin-top: 14px;
    padding: 16px;
    overflow-x: hidden;
    overflow-y: auto;
}

iframe {
    background-color: black;
    margin-top: 10px;
    border: none;
    border-radius: 12px;
    width: 100%;
    height: 220px; 
}

/* width */
::-webkit-scrollbar {
    width: 10px;
}

/* Track */
::-webkit-scrollbar-track {
    background: #727272;
}

/* Handle */
::-webkit-scrollbar-thumb {
    background: rgb(44, 44, 44);
}

/* Handle on hover */
::-webkit-scrollbar-thumb:hover {
    background: rgb(71, 71, 71);
}