Constant EUV_MD_CSS 

pub const EUV_MD_CSS: &str = r#"
.md-body {
    line-height: 1.7;
    font-size: var(--font-base);
    word-wrap: break-word;
}
.md-body h1, .md-body h2, .md-body h3, .md-body h4, .md-body h5, .md-body h6 {
    position: relative;
    font-weight: 700;
    letter-spacing: -0.01em;
    margin-top: 1.8em;
    margin-bottom: 0.6em;
    scroll-margin-top: 72px;
    line-height: 1.3;
}
.md-body h1 {
    font-size: var(--font-3xl);
    margin-top: 0;
    padding-bottom: 0.4em;
    border-bottom: 1px solid var(--border);
}
.md-body h2 {
    font-size: var(--font-2xl);
    padding-bottom: 0.3em;
    border-bottom: 1px dashed var(--border);
}
.md-body h3 { font-size: var(--font-xl); }
.md-body h4 { font-size: var(--font-lg); }
.md-body h5, .md-body h6 { font-size: var(--font-base); }
.md-body .header-anchor {
    float: left;
    margin-left: -0.9em;
    padding-right: 0.2em;
    opacity: 0;
    color: var(--muted-foreground);
    font-weight: 400;
    transition: opacity 0.15s ease-out;
    user-select: none;
}
.md-body h1:hover .header-anchor,
.md-body h2:hover .header-anchor,
.md-body h3:hover .header-anchor,
.md-body h4:hover .header-anchor,
.md-body h5:hover .header-anchor,
.md-body h6:hover .header-anchor {
    opacity: 1;
}
.md-body p, .md-body ul, .md-body ol, .md-body blockquote, .md-body pre, .md-body table {
    margin: 1em 0;
}
.md-body ul, .md-body ol {
    padding-left: 1.4em;
}
.md-body ul { list-style: disc; }
.md-body ol { list-style: decimal; }
.md-body ul ul, .md-body ul ol, .md-body ol ul, .md-body ol ol {
    margin: 0.25em 0;
}
.md-body li { margin: 0.25em 0; }
.md-body li input[type="checkbox"] {
    margin-right: 0.4em;
    accent-color: var(--accent);
}
.md-body a {
    color: var(--accent);
    font-weight: 500;
    text-decoration: underline;
    text-underline-offset: 3px;
    text-decoration-style: dashed;
    text-decoration-color: var(--border);
}
.md-body a:hover {
    text-decoration-style: solid;
    text-decoration-color: var(--accent);
}
.md-body strong { font-weight: 700; }
.md-body em { font-style: italic; }
.md-body del { opacity: 0.6; }
.md-body hr {
    border: none;
    border-top: 1px dashed var(--border);
    margin: 2em 0;
}
.md-body blockquote {
    margin: 1em 0;
    padding: 0.4em 1em;
    border-left: 4px solid var(--border);
    color: var(--muted-foreground);
}
.md-body blockquote p { margin: 0.4em 0; }
.md-body code {
    font-family: ui-monospace, monospace;
    font-size: 0.875em;
    padding: 0.15em 0.4em;
    background: var(--accent-muted);
    border: 1px solid var(--border);
    /* Inline <code> that wraps to multiple lines must keep its border
       on every fragment, otherwise the first line loses its right border
       and subsequent lines lose their left border.

       box-decoration-break: clone alone is not enough in practice: the
       per-fragment borders stack against the next fragment's background
       and the visual gap between fragments collapses, making the right
       border of one line look like the left border of the next (and
       neither looks fully closed). Making the element inline-block
       guarantees each fragment draws its own box with its own four
       borders, exactly the same trick used by euv_tag. */
    -webkit-box-decoration-break: clone;
    box-decoration-break: clone;
    display: inline-block;
    vertical-align: text-top;
    line-height: 1.4;
}
.md-body pre {
    padding: 1em 1.2em;
    overflow-x: auto;
    border: 1px solid var(--border);
    background: var(--accent-muted);
}
.md-body pre code {
    padding: 0;
    border: none;
    background: transparent;
    font-size: 0.875rem;
    line-height: 1.6;
}
.md-body table {
    width: 100%;
    border-collapse: collapse;
    font-size: var(--font-sm);
    display: block;
    overflow-x: auto;
}
.md-body table thead { border-bottom: 2px solid var(--border); }
.md-body table th, .md-body table td {
    padding: 0.5em 0.9em;
    border: 1px solid var(--border);
    text-align: left;
}
.md-body table th { font-weight: 700; }
.md-body table tbody tr:nth-child(2n) { background: var(--accent-muted); }
.md-body img { max-width: 100%; }
.md-body .docs-container {
    margin: 1.2em 0;
    padding: 0.1em 1.2em;
    border-left: 4px solid var(--foreground);
    background: var(--accent-muted);
}
.md-body .docs-container .docs-container-title {
    font-weight: 700;
    font-size: var(--font-sm);
    letter-spacing: 0.04em;
    text-transform: uppercase;
    margin: 0.8em 0 0.4em;
}
.md-body .docs-container.tip { border-left-style: solid; }
.md-body .docs-container.warning { border-left-style: dashed; }
.md-body .docs-container.danger {
    border-left: 4px double var(--foreground);
}
.md-body .docs-container.details {
    border-left: 1px solid var(--border);
    background: transparent;
}
.md-body .footnote-definition { font-size: var(--font-sm); color: var(--muted-foreground); }
"#;

Raw stylesheet for rendered markdown bodies (crate::euv_markdown).

class! cannot express descendant selectors, so markdown typography is injected once at startup through Css::inject_css. All colors reference the theme CSS variables, so light/dark switching works unchanged.