html, .Solved, .IntegralList, .Pass, .Close {
    background: #212529; 
    color: #e0e0e0;
    font-family: Bahnschrift;
}

#tit {
    font-size: 70px;
    background: #1b1f22;
    justify-content: center;
    width: 700px;
    display: flex;
    border-radius: 10px;
    margin: 0 auto;
    padding: 5px;
}

#aside, #bside {
    width: 150px;
    background: #1b1f22;
    height: 150px;
    border-radius: 10px;
    padding: 10px;
}

#formula {
    margin: 0 50px 0 50px;
    background-color: #1b1f22;
    border-radius: 10px;
    padding: 0 25px 0 25px;
    align-content: center;
}

#mother {
    display: flex;
    justify-content: center;
}

.chk {
    margin-bottom: 5px;
}

.IntegralList {
    padding: 10px 20px;
    background-color: #1d2d3f;
    border-radius: 10px;
    cursor: pointer;
    transition: background-color 0.3s;
    width: 115px;
    border-width: 0;
    display: flex;
}

.IntegralList:hover {
    background-color: #0056b3;
}

.Solved {
    padding: 10px 20px;
    background-color: #203f1d;
    border-radius: 10px;
    cursor: pointer;
    transition: background-color 0.3s;
    width: 80px;
    border-width: 0;
    display: flex;
}

.Solved:hover {
    background-color: #00910c;
}

.Pass {
    padding: 10px 20px;
    background-color: #3f1d1d;
    border-radius: 10px;
    cursor: pointer;
    transition: background-color 0.3s;
    width: 70px;
    border-width: 0;
    display: flex;
}

.Pass:hover {
    background-color: #910000;
}

#stat {
    display: flex;
    justify-content: center;
}

#bside, #afterrun {
    align-items: center;
    display: flex;
    flex-direction: column;
}

#afterrun {
    visibility: hidden;
}

.popup-overlay {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.5);
    justify-content: center;
    align-items: center;
}

.popup-content {
    background: #212529;
    padding: 20px;
    border-radius: 8px;
    align-items: center;
    overflow-y: scroll;
    width: 820px;
    height: 500px;
}

.Close{
    padding: 10px 20px;
    background-color: #1b1f22;
    border-radius: 10px;
    cursor: pointer;
    transition: background-color 0.3s;
    width: 75px;
    border-width: 0;
    margin: 0 auto;
    display: flex;
}

.Close:hover {
    background-color: #3e474e;
}

h1 {
    text-align: center;
}

.popup-content::-webkit-scrollbar {
    width: 10px;
}

.popup-content::-webkit-scrollbar-track {
    background: #212529;
    border-radius: 10px;
}

.popup-content::-webkit-scrollbar-thumb {
    background: #888;
    border-radius: 10px;
}

.popup-content::-webkit-scrollbar-thumb:hover {
    background: #555;
}