@font-face {
    font-family: "CMU Serif";
    src: url("fonts/cmun/cmunorm.otf") format("truetype");
    font-weight: normal;
    font-style: normal;
}

@font-face {
    font-family: "CMU Serif";
    src: url("fonts/cmun/cmunsl.otf") format("truetype");
    font-weight: normal;
    font-style: italic;
}

@font-face {
    font-family: "CMU Serif";
    src: url("fonts/cmun/cmunbx.otf") format("truetype");
    font-weight: bold;
    font-style: normal;
}

@font-face {
    font-family: "CMU Serif";
    src: url("fonts/cmun/cmunbi.otf") format("truetype");
    font-weight: bold;
    font-style: italic;
}

body {font-family: "CMU Serif", "Times New Roman", serif;}



.theorem,
.task {
    background-color: #f9f9f9;
    border-left: 6px solid rgba(44, 95, 45, 0.5);
    margin: 20px 0;
    padding: 10px 20px;
    font-family: "Arial", sans-serif;
    font-size: 18px;
    color: #333;
}

.inside_1 {
    background-color: #fff;
    border: 1px solid #eee;
    padding: 10px;
    margin-top: 10px;
    font-family: "Courier New", monospace;
    font-size: 16px;
    color: #000;
}
.explain {
    border-left: 1px solid #000;
    padding-left: 1rem;
}
ul {
    list-style-type: square;
    line-height: 2rem;
}

footer {
    display: block;
    margin-top: 5rem;
}

img {
    max-width: 13rem;
}
.lh_2rem {
    line-height: 2rem;
}
.lh_3rem {
    line-height: 3rem;
}
.bg_green {
    background-color: rgba(44, 95, 45, 0.2);
}

/* index.html */
html,
body {
    height: 100%;
    margin: 0;
    padding: 0;
}

.container-fluid,
.row {
    height: 100%;
}

iframe {
    display: block;
    width: 100%;
    height: calc(100vh - 2rem);
    border: none;
    overflow-y: auto;
    overflow-x: hidden;
}

.link {
    border: 1px solid #ddd;
    padding: 0.3rem 1rem;
    margin: 1rem;
    border-radius: 10px;
    color: rgba(44, 95, 45, 0.5);
}
a:link,
a:visited,
a:active {
    color: rgba(44, 95, 45, 0.8);
}

/* Mobile responsive styles */
@media (max-width: 767px) {
    html,
    body {
        height: auto;
        overflow-x: hidden;
        font-family: Helvetica, sans-serif;
    }

    .container-fluid,
    .row {
        height: auto;
    }

    iframe {
        height: 70vh;
        min-height: 400px;
    }

    .link {
        margin: 0.5rem;
        padding: 0.5rem 0.8rem;
        font-size: 0.9rem;
    }

    .theorem,
    .task {
        padding: 8px 12px;
        font-size: 16px;
        margin: 10px 0;
    }

    .inside_1 {
        font-size: 14px;
        padding: 8px;
    }

    img {
        max-width: 100%;
        height: auto;
    }
}