/* ── CSS Custom Properties ── */
:root {
    --bg-color: #fffff8;
    --text-color: #111;
    --link-color: #111;
    --nav-border: #ccc;
    --footer-border: #ccc;
    --muted: #666;
    --hover-bg: rgba(0, 0, 0, 0.04);
    --abstract-color: #555;
}

@media (prefers-color-scheme: dark) {
    :root:not([data-theme="light"]) {
        --bg-color: #151515;
        --text-color: #ddd;
        --link-color: #ddd;
        --nav-border: #444;
        --footer-border: #444;
        --muted: #999;
        --hover-bg: rgba(255, 255, 255, 0.06);
        --abstract-color: #aaa;
    }
}

[data-theme="dark"] {
    --bg-color: #151515;
    --text-color: #ddd;
    --link-color: #ddd;
    --nav-border: #444;
    --footer-border: #444;
    --muted: #999;
    --hover-bg: rgba(255, 255, 255, 0.06);
    --abstract-color: #aaa;
}

/* ── Apply theme variables ── */
body {
    background-color: var(--bg-color);
    color: var(--text-color);
}

/* ── Override Tufte's complex link underlines ── */
a:link, a:visited,
.tufte-underline, .hover-tufte-underline:hover {
    background: none !important;
    text-shadow: none !important;
    text-decoration: none;
    border-bottom: 1px solid var(--muted);
}

a:hover {
    border-bottom-color: var(--text-color);
}

/* ── Nav ── */
nav.site-nav {
    display: flex;
    align-items: baseline;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 0.5rem 1.5rem;
    padding: 1rem 0 0.8rem;
    border-bottom: 1px solid var(--nav-border);
    font-size: 1.1rem;
}

nav.site-nav a {
    border-bottom: none;
}

nav.site-nav a:hover {
    border-bottom: 1px solid var(--muted);
}

nav.site-nav .nav-name {
    font-variant: small-caps;
    font-size: 1.4rem;
    letter-spacing: 0.05em;
}

nav.site-nav .nav-links {
    display: flex;
    align-items: center;
    gap: 1.2rem;
    flex-wrap: wrap;
}

nav.site-nav .nav-links a {
    color: var(--muted);
}

nav.site-nav .nav-links a:hover,
nav.site-nav .nav-links a.active {
    color: var(--text-color);
}

/* ── Dark Mode Toggle ── */
button.theme-toggle {
    background: none;
    border: none;
    cursor: pointer;
    font-size: 1.2rem;
    padding: 0.2rem 0.4rem;
    color: var(--muted);
    line-height: 1;
}

button.theme-toggle:hover {
    color: var(--text-color);
}

/* ── Footer ── */
footer.site-footer {
    border-top: 1px solid var(--footer-border);
    padding: 1rem 0;
    margin-top: 3rem;
    font-size: 0.95rem;
    color: var(--muted);
}

footer.site-footer a {
    color: var(--muted);
}

/* ── Blog Index: Marginalia ── */
.blog-index .year-group {
    margin-top: 2.5rem;
}

.blog-index .year-heading {
    font-variant: small-caps;
    font-size: 1.6rem;
    font-weight: 400;
    font-style: normal;
    letter-spacing: 0.05em;
    margin-bottom: 1rem;
}

.blog-index .post-entry {
    position: relative;
    width: 55%;
    margin-bottom: 1.2rem;
}

.blog-index .post-entry .post-title {
    font-size: 1.4rem;
    line-height: 2rem;
}

.blog-index .post-entry .post-title a {
    border-bottom: 1px solid var(--muted);
}

.blog-index .post-entry .post-title a:hover {
    border-bottom-color: var(--text-color);
}

.blog-index .post-entry .post-date,
.blog-index .post-entry .post-abstract {
    float: right;
    clear: right;
    margin-right: -60%;
    width: 50%;
    margin-top: 0;
    font-size: 1.1rem;
    line-height: 1.3;
    color: var(--muted);
    transition: opacity 0.25s ease;
}

.blog-index .post-entry .post-abstract {
    position: absolute;
    top: 0;
    left: 110%;
    width: 50%;
    float: none;
    font-style: italic;
    color: var(--abstract-color);
    opacity: 0;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.blog-index .post-entry:hover .post-date {
    opacity: 0;
}

.blog-index .post-entry:hover .post-abstract {
    opacity: 1;
}

/* ── Article-level width constraint (matches Tufte's section > p) ── */
article > p,
article > footer,
article > table {
    width: 55%;
}

article > dl,
article > ol,
article > ul {
    width: 50%;
    -webkit-padding-start: 5%;
}

article > blockquote p,
article > blockquote footer {
    width: 55%;
}

/* Fix blockquote sidenote alignment — tufte.css uses margin-right: -82%
   which overcompensates. The calc value compensates for blockquote's
   40px browser-default margins and the wider min-width (59% vs 50%). */
blockquote .sidenote,
blockquote .marginnote {
    margin-right: calc(-60% - 70px);
}

/* ── Date in blog post header ── */
.post-meta {
    font-size: 1.1rem;
    color: var(--muted);
    margin-top: -1rem;
    margin-bottom: 2rem;
}

/* ── Responsive ── */
@media (max-width: 760px) {
    nav.site-nav {
        flex-direction: column;
        gap: 0.3rem;
    }

    .blog-index .post-entry {
        width: 100%;
    }

    .blog-index .post-entry .post-date {
        float: none;
        margin-right: 0;
        width: auto;
        display: block;
        margin-bottom: 0.3rem;
    }

    .blog-index .post-entry .post-abstract {
        float: none;
        margin-right: 0;
        width: auto;
        opacity: 1;
    }
}