*{
    padding: 0;
    margin: 0;
}
::-webkit-scrollbar{ width: 7px;}
::-webkit-scrollbar-thumb{ background-color: #1c1c1c;}
::-webkit-scrollbar-track{ background: #3d3d3d;}
a{
    text-decoration: none;
    color: #efffe3;
}
a:hover{
    color: #80BCBD;
    text-decoration: underline;
}
.background{
    background-color: black;
    background-repeat: repeat;
    background-size: 300px;
}
.floating_solid_band{
    width: 90%;
    height: auto;
    border-radius: 1%;
    margin-left: 5%;
    margin-right: 5%;
    text-align: center;
    background: #1c1c1c;
}
.list{
    font-family:sans-serif;
    font-size: 30px;
    color: #f5f5f5;
    text-align: left;
    display: block;
    width: 90%;
    margin-left: 5%;
    padding-left: 20px;
    box-sizing: border-box;
}
.list li{
    margin-bottom: 10px;
    word-wrap: break-word;
    overflow-wrap: break-word;
    max-width: 100%;
}
.centered-list {
    font-family: sans-serif;
    font-size: 30px;
    color: #f5f5f5;
    padding-left: 20px;
    text-align: left;
    display: inline-block;
}
.centered-list li {
    margin-left: 0;
    padding-bottom: 10px;
}
.index-list{
    list-style: decimal;
    padding-left: 20px;
    text-align: left;
    display: inline-block;
}
.index-list li{
    margin-left: 0;
    padding-bottom: 10px;
    padding-top: 15px;
    font-size: 40px;
    font-family: sans-serif;
    color: #f5f5f5;
}
.index-list li::marker{
    font-size: 40px;
    font-family: sans-serif;
    color: #f5f5f5;
}
.index-list li:hover,
.index-list li:hover::marker{
    color: #80BCBD;
    text-decoration: underline;
}
.supertitle{
    font-size: 100px;
    margin-bottom: 20px;
    font-family: "Sometype Mono", monospace;
    color: #f5f5f5;
}
.supertitle_2{
    font-size: 40px;
    font-family: "Mooli", sans-serif;
    margin: 0;
    color: #f5f5f5;
}
.subtitle{
    font-size: 40px;
    font-family: "Mooli", sans-serif;
    padding: 5px;
    color: #f5f5f5;
    background-color: #3d3d3d;
}
.index{
    font-family:sans-serif;
    font-size: 40px;
    color: #f5f5f5;
    padding-top: 20px;
    padding-bottom: 20px;
    text-decoration: none;
}
.text{
    font-family:sans-serif;
    margin: 50px;
    font-size: 30px;
    color: #f5f5f5;
    text-align: justify;
}
.green-text{
    color: #7CFC00;
}
.red-text{
    color: red;
}
.text ul{
    font-family: "Sometype Mono", monospace;
    margin-left: 500px;
    font-size: 30px;
    color: #f5f5f5;
}
.text ol{
    font-family: "Sometype Mono", monospace;
    font-size: 30px;
    color: #f5f5f5;
}
.text-code{
    background-color: #2a2a2a;
    color: #74b9ff;
    font-family: "Courier New", Courier, monospace;
    font-size: 0.95em;
    padding: 2px 6px;
    border-radius: 4px;
    display: inline-block;
}
.medium-number{
    width: 150px;
    height: 150px;
    background-color: black;
    color: #f5f5f5;
    font-size: 30px;
    font-weight: bold;
    display: flex;
    justify-content: center;
    align-items: center;
    border-radius: 50%;
    box-shadow: 0 4px 8px #3d3d3d;
    margin-left: 30px;
    margin-top: -50px;
}
.big-number{
    width: 200px;
    height: 200px;
    background-color: black;
    color: #f5f5f5;
    font-size: 40px;
    font-weight: bold;
    display: flex;
    justify-content: center;
    align-items: center;
    border-radius: 50%;
    box-shadow: 0 4px 8px #3d3d3d;
    margin-left: 30px;
    margin-top: -50px;
}
.previous-lesson {
    font-family: "Sometype Mono", monospace;
    font-size: 35px;
    color: #74B9FF;
    text-align: center;
    margin: 20px 0;
    padding: 10px;
    background-color: #1c1c1c;
    border-radius: 10px;
    display: inline-block;
    width: auto;
    box-shadow: 0 10px 8px 5px rgba(0, 0, 0, 0.5);
    transition: all 0.3s ease;
}
.previous-lesson:hover {
    color: #A8D8FF;
    background-color: #3d3d3d;
    box-shadow: 0 20px 12px rgba(0, 0, 0, 0.7);
    transform: translateY(-2px);
}.following-lesson {
    font-family: "Sometype Mono", monospace;
    font-size: 35px;
    color: #E65A50;
    text-align: center;
    margin: 20px 0;
    padding: 10px;
    background-color: #1c1c1c;
    border-radius: 10px;
    display: inline-block;
    width: auto;
    box-shadow: 0 10px 8px 5px rgba(0, 0, 0, 0.5);
    transition: all 0.3s ease;
}
.following-lesson:hover {
    color: #E6B84C;
    background-color: #3d3d3d;
    box-shadow: 0 20px 12px rgba(0, 0, 0, 0.7);
    transform: translateY(-2px);
}
.topic_container{
    background-color: #3d3d3d;
    position: relative;
    margin-left: 5%;
    margin-right: 5%;
    margin-bottom: 20px;
    padding: 2%;
    text-align: left;
    list-style: none;
    height: auto;
    display: flex;
    align-items: center;
}
.topic_image{
    position: relative;
    left: 0;
    top: 0;
    width: 10vw;
    height: auto;
    margin-right: 20px
}
.bound_image{
    margin-left: 15px;
    margin-top: 20px;
    margin-bottom: 50px;
    width: 40vw;
    height: auto;
    display: block;
    margin-left: auto;
    margin-right: auto;
}
.floating_image{
    position: fixed;
    top: 10px;
    right: 10px;
    width: 100px;
    height: auto;
    z-index: 9999;
}
.cf_problem ol li p{
    margin-left: 1%;
    display: inline;
}
.cf_icon{
    height: 40px;
    width: auto;
}.CSES_icon{
    height: 30px;
    width: auto;
}
@media screen and (max-width: 767px){
    nav{
        padding: 0px;
    }
    nav ul li{
        display: block;
        padding: 5px;
    }
    .text{
        font-size: 20px;
        margin: 20px;
    }
    .list{
        font-size: 20px;
    }
    .list li{
        margin-left: 4px;
    }
    .centered-list{
        font-size: 20px;
    }
    .responsive_text{
        font-size: 2.5vw;
    }
    .supertitle{
        font-size: 13vw;
    }
    .responsive_floating_band{
        height: 30vw;
    }
    .icons{
        height: 9vw;
        width: auto;
    }
    .band{
        margin-top: 160px;
    }
    .bound_image{
        width: 100%;
        height: auto;
    }
    .math-L-eq{
        display: block;
        max-width: 100%;
        font-size: 0.85em;
        transform: scale(0.85);
        transform-origin: left top;
    }
    .math-XL-eq{
        display: block;
        max-width: 100%;
        font-size: 0.75em;
        transform: scale(0.75);
        transform-origin: left top;
    }
    .index{
        font-size: 30px;
    }
    .index-list li{
        margin-left: 20px;
    }
    .index-list li::marker{
        font-size: 30px;
    }
    .cf_icon{
        height: 25px;
    }
    .CSES_icon{
        height: 15px;
    }
    .cf_problem ol li p{
        margin-left: 5%;
    }
    .medium-number{
        margin-top: 1px;
        width: 50px;
        height: 50px;
        font-size: 10px;
    }
    .big-number{
        margin-top: 1px;
        width: 100px;
        height: 100px;
        font-size: 20px;
    }
}
@media screen and (min-width: 768px) and (max-width: 1023px){
    .responsive_text{
        font-size: 3vw;
    }
    .responsive_floating_band{
        height: 35vw;
    }
    .icons{
        height: 9vw;
        width: auto;
    }
    nav ul li{
        padding: 20px;
    }
    .bound_image{
        width: 500px;
        height: auto;
    }
}