body {
    font-family: "Segoe UI", Arial, sans-serif;
    background: #f7f9fb;
    color: #333;
    margin: 0;
    padding: 0;
}
.container {
    max-width: 900px;
    margin: 40px auto;
    background: #fff;
    box-shadow: 0 2px 12px rgba(0, 0, 0, 0.1);
    border-radius: 12px;
    padding: 2em 2em 3em 2em;
}
h1,
h2 {
    color: #1d3557;
    margin-bottom: 0.3em;
}
h2 {
    margin-top: 1.8em;
    font-size: 1.2em;
    border-left: 4px solid #457b9d;
    padding-left: 0.5em;
}
.lead {
    color: #555;
    margin-bottom: 1em;
    font-size: 1.1em;
}
pre {
    background: #23272e;
    color: #eee;
    padding: 1em;
    border-radius: 8px;
    overflow-x: auto;
    margin: 1em 0;
    font-size: 1em;
    line-height: 1.5;
}
.toggle-btn {
    background: #457b9d;
    color: #fff;
    border: none;
    border-radius: 5px;
    padding: 0.5em 1.2em;
    font-size: 1em;
    cursor: pointer;
    margin-bottom: 1em;
    transition: background 0.2s;
}
.toggle-btn:hover {
    background: #1d3557;
}
.note {
    background: #e9f5ff;
    border-left: 4px solid #48cae4;
    padding: 0.8em 1em;
    margin: 1.3em 0;
    border-radius: 6px;
    color: #02568a;
    font-size: 0.98em;
}
#plot3d {
    width: 100%;
    max-width: 700px;
    height: 430px;
    margin: 2em auto;
    border-radius: 8px;
    box-shadow: 0 2px 8px rgba(34, 54, 80, 0.11);
    background: #fafaff;
}
@media (max-width: 700px) {
    .container {
        padding: 1em;
    }
    #plot3d {
        max-width: 100%;
    }
}
/* Light syntax highlighting for keywords */
.hl-key {
    color: #c792ea;
}
.hl-func {
    color: #89ddff;
}
.hl-str {
    color: #ecc48d;
}
.hl-comm {
    color: #7f848e;
    font-style: italic;
}
.hl-num {
    color: #f78c6c;
}