body {
    margin: 0;
    font-family: "Roboto", sans-serif;
    background: linear-gradient(145deg, #0d0d0d, #1a1a1a);
    color: white;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: flex-start;
    min-height: 100vh;
    padding: 20px;
}
.container {
    width: 90%;
    max-width: 900px;
    text-align: center;
    padding: 30px;
    border-radius: 25px;
}
.glass {
    background: rgba(255, 255, 255, 0.08);
    border: 1px solid rgba(255, 255, 255, 0.15);
    box-shadow: 0 4px 30px rgba(0, 0, 0, 0.6);
    backdrop-filter: blur(20px) saturate(150%);
}
h1 {
    font-size: 70px;
    margin-bottom: 40px;
    text-shadow: 0 0 15px rgba(255, 255, 255, 0.3);
}
.equation {
    font-size: 70px;
    display: flex;
    justify-content: center;
    align-items: center;
    margin: 20px 0;
    flex-wrap: wrap;
    padding: 20px;
    border-radius: 25px;
    background: rgba(255, 255, 255, 0.07);
    border: 1px solid rgba(255, 255, 255, 0.15);
    box-shadow: 0 0 15px rgba(0, 0, 0, 0.4);
    backdrop-filter: blur(10px);
}
input[type="number"] {
    width: 160px;
    font-size: 60px;
    text-align: center;
    border: none;
    border-radius: 20px;
    background: rgba(255, 255, 255, 0.1);
    color: white;
    outline: none;
    transition: all 0.3s ease;
}
input[type="number"]:focus {
    box-shadow: 0 0 20px rgba(220, 0, 0, 0.8);
}
button {
    background: rgba(255, 255, 255, 0.1);
    border: 2px solid rgba(255, 255, 255, 0.2);
    border-radius: 15px;
    color: white;
    font-size: 55px;
    margin-left: 10px;
    padding: 10px 25px;
    cursor: pointer;
    transition: all 0.3s ease;
}
button:hover {
    border-color: #ff0000;
    box-shadow: 0 0 15px rgba(255, 0, 0, 0.6);
}
.icon {
    margin-left: 10px;
    font-size: 65px;
    transition: all 0.3s ease;
}
.icon.correct {
    color: limegreen;
    text-shadow: 0 0 15px rgba(255, 0, 0, 0.8);
}
.icon.wrong {
    color: red;
}
#reset {
margin-top: 40px;
font-size: 55px;
border-color: #ff0000;
}
@media (max-width: 600px) {
    h1 {
        font-size: 25px;
    }
    .equation {
        font-size: 28px;
        padding: 7px;
        margin: 10px 0;
    }
    input[type="number"] {
        width: 45px;
        font-size: 25px;
    }
    button {
        font-size: 16px;
        padding: 3px 10px;
    }
    #reset {
        font-size: 16px;
        margin-top: 0px;
    }
    .icon {
        font-size: 18px;
    }
}