:root {
    --bg: #0a0e1a;
    --bg-surface: #121829;
    --bg-code: #080c14;
    --text: #e2e8f0;
    --muted: #8892a4;
    --line: #1e2d45;
    --heading: #f1f5f9;
    --accent: #a78bfa;
    --accent-soft: rgba(167, 139, 250, 0.15);
}

* {
    box-sizing: border-box;
}

body {
    margin: 0;
    font-family: "Avenir Next", "Segoe UI", system-ui, -apple-system, sans-serif;
    color: var(--text);
    background:
        radial-gradient(ellipse at 20% -5%, rgba(88, 28, 135, 0.25) 0%, transparent 50%),
        radial-gradient(ellipse at 90% 5%, rgba(29, 78, 216, 0.2) 0%, transparent 45%),
        var(--bg);
    line-height: 1.75;
    min-height: 100vh;
    padding: 2.5rem 1.25rem 3rem;
}

.site-header,
main,
footer {
    width: min(100%, 860px);
    margin: 0 auto;
}

.site-header {
    display: flex;
    align-items: flex-end;
    justify-content: space-between;
    gap: 1rem;
    border-bottom: 1px solid var(--line);
    padding-bottom: 0.95rem;
    margin-bottom: 2.1rem;
}

.masthead {
    display: flex;
    flex-direction: column;
    gap: 0.2rem;
}

.brand {
    color: var(--heading);
    text-decoration: none;
    font-weight: 700;
    letter-spacing: 0.02em;
    font-size: 1.1rem;
    text-shadow: 0 0 20px rgba(167, 139, 250, 0.4);
}

.tagline {
    color: var(--muted);
    font-size: 0.8rem;
    text-transform: uppercase;
    letter-spacing: 0.09em;
}

.site-nav ul {
    list-style: none;
    margin: 0;
    padding: 0;
    display: flex;
    align-items: center;
    gap: 1.5rem;
    flex-wrap: wrap;
}

.site-nav li {
    position: relative;
}

.site-nav a {
    color: var(--muted);
    text-decoration: none;
    font-size: 0.9rem;
    transition: color 0.2s ease;
    white-space: nowrap;
}

.site-nav a:hover,
.site-nav a:focus-visible {
    color: var(--accent);
}

/* Sub-menu (nested ul) */
.site-nav li > ul {
    position: absolute;
    top: 100%;
    left: 0;
    background: var(--bg-surface);
    border: 1px solid var(--line);
    border-radius: 8px;
    padding: 0.5rem 0;
    min-width: 160px;
    flex-direction: column;
    gap: 0;
    opacity: 0;
    visibility: hidden;
    transform: translateY(4px);
    transition: opacity 0.2s ease, transform 0.2s ease, visibility 0.2s;
    z-index: 100;
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.25);
}

.site-nav li:hover > ul,
.site-nav li:focus-within > ul {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.site-nav li > ul li {
    width: 100%;
}

.site-nav li > ul a {
    display: block;
    padding: 0.4rem 1rem;
    font-size: 0.85rem;
}

.site-nav li > ul a:hover {
    background: var(--accent-soft);
}

/* Footer navigation */
.footer-nav ul {
    list-style: none;
    margin: 0;
    padding: 0;
    display: flex;
    align-items: center;
    gap: 1.25rem;
    flex-wrap: wrap;
}

.footer-nav a {
    color: var(--muted);
    text-decoration: none;
    font-size: 0.85rem;
    transition: color 0.2s ease;
}

.footer-nav a:hover {
    color: var(--accent);
}

.footer-nav {
    margin-bottom: 0.75rem !important;
}

main {
    min-height: 60vh;
}

h1,
h2,
h3 {
    color: var(--heading);
    line-height: 1.25;
    letter-spacing: -0.01em;
    text-shadow: 0 0 30px rgba(167, 139, 250, 0.2);
}

h1 {
    margin: 0;
    font-size: clamp(2rem, 4vw, 2.5rem);
}

h2 {
    font-size: clamp(1.45rem, 2.9vw, 1.8rem);
}

h3 {
    font-size: 1.2rem;
}

p {
    margin: 1rem 0;
}

a {
    color: var(--accent);
    text-decoration: none;
}

a:hover,
a:focus-visible {
    text-decoration: underline;
}

.post {
    background: linear-gradient(180deg, rgba(167, 139, 250, 0.04), rgba(167, 139, 250, 0));
    border: 1px solid var(--line);
    border-radius: 12px;
    padding: 1.25rem 1.3rem 1.4rem;
}

.post-header {
    border-bottom: 1px solid var(--line);
    padding-bottom: 0.95rem;
    margin-bottom: 1.2rem;
}

.post-meta {
    margin: 0.35rem 0 0;
    color: var(--muted);
    font-size: 0.9rem;
}

.index-intro {
    margin-bottom: 1.4rem;
}

.eyebrow {
    margin: 0 0 0.4rem;
    color: var(--accent);
    font-size: 0.8rem;
    text-transform: uppercase;
    letter-spacing: 0.12em;
}

.lead {
    margin-top: 0.6rem;
    color: var(--muted);
}

.post-list {
    display: grid;
    gap: 1rem;
}

.post-preview {
    background: var(--bg-surface);
    border: 1px solid var(--line);
    border-radius: 10px;
    padding: 1rem 1.1rem;
    transition: border-color 0.2s ease, transform 0.2s ease, box-shadow 0.2s ease;
}

.post-preview:hover {
    border-color: var(--accent);
    box-shadow: 0 0 20px rgba(167, 139, 250, 0.12);
    transform: translateY(-2px);
}

.post-preview h2 {
    margin: 0;
}

.post-preview h2 a {
    color: var(--heading);
}

.post-preview h2 a:hover,
.post-preview h2 a:focus-visible {
    color: var(--accent);
    text-decoration: none;
}

.post-date {
    display: block;
    margin-top: 0.45rem;
    color: var(--muted);
    font-size: 0.88rem;
}

pre {
    background: var(--bg-code);
    color: #dce4ef;
    border: 1px solid var(--line);
    border-radius: 10px;
    padding: 1rem;
    overflow-x: auto;
}

code {
    font-family: "JetBrains Mono", "SFMono-Regular", Menlo, Consolas, monospace;
    font-size: 0.9em;
    background: var(--accent-soft);
    border-radius: 6px;
    padding: 0.15em 0.35em;
}

pre code {
    background: transparent;
    padding: 0;
    border-radius: 0;
}

blockquote {
    margin: 1.2rem 0;
    border-left: 3px solid #5b4f8a;
    padding-left: 1rem;
    color: #b0b8cc;
    white-space: pre-wrap;
}

.extension {
    margin: 1rem 0;
    padding: 0.95rem 1rem;
    border-radius: 8px;
    background: #111828;
    border: 1px solid var(--line);
    border-left: 4px solid var(--line);
}

.extension[data-name="callout"],
.extension[data-args="info"],
.extension[data-name="info"] {
    border-left: 4px solid #60a5fa;
    background: rgba(96, 165, 250, 0.06);
}

.extension[data-args="warning"],
.extension[data-name="warning"] {
    border-left: 4px solid #fbbf24;
    background: rgba(251, 191, 36, 0.06);
}

.extension[data-args="error"],
.extension[data-name="error"] {
    border-left: 4px solid #f87171;
    background: rgba(248, 113, 113, 0.06);
}

img {
    max-width: 100%;
    border-radius: 8px;
}

hr {
    border: 0;
    border-top: 1px solid var(--line);
    margin: 2rem 0;
}

footer {
    margin-top: 2.4rem;
    border-top: 1px solid var(--line);
    padding-top: 1rem;
    color: var(--muted);
    font-size: 0.85rem;
}

@media (max-width: 640px) {
    body {
        padding-top: 1.5rem;
    }

    .site-header {
        flex-direction: column;
        align-items: flex-start;
    }

    .post {
        padding: 1rem;
    }
}


/* Smarkdown Specific Styles */

.callout {
    padding: 1rem;
    border-radius: 8px;
    background: rgba(125, 125, 125, 0.08);
    border: 1px solid rgba(125, 125, 125, 0.15);
    margin: 1rem 0;
    border-left: 4px solid var(--accent);
}

.callout-title {
    font-weight: 600;
    margin-bottom: 0.5rem;
    display: flex;
    align-items: center;
}

.callout-info {
    border-left-color: #60a5fa;
    background: rgba(96, 165, 250, 0.08);
}

.callout-danger,
.callout-error {
    border-left-color: #f87171;
    background: rgba(248, 113, 113, 0.08);
}

.callout-warning {
    border-left-color: #fbbf24;
    background: rgba(251, 191, 36, 0.08);
}

.callout-success {
    border-left-color: #4ade80;
    background: rgba(74, 222, 128, 0.08);
}

.math {
    font-family: 'Cambria Math', 'Latin Modern Math', serif;
    color: inherit;
}

.math-block {
    display: block;
    text-align: center;
    margin: 1rem 0;
    font-size: 1.2em;
}

mark {
    background-color: rgba(167, 139, 250, 0.3);
    padding: 0 0.2em;
    border-radius: 3px;
    color: var(--heading);
}

.task-list-item {
    list-style-type: none;
    margin-left: -1.5rem;
}

.task-list-item input {
    margin-right: 0.5rem;
    accent-color: var(--accent);
}

img.embed-image {
    max-width: 100%;
    height: auto;
    border-radius: 8px;
    margin: 1rem 0;
}

/* Smarkdown Newsletter Form Styles */
.smarkdown-newsletter {
    background: var(--bg-surface);
    border: 1px solid var(--line);
    border-radius: 12px;
    padding: 1.5rem;
    margin: 2rem 0;
    box-shadow: 0 4px 14px rgba(0, 0, 0, 0.03);
}

.smarkdown-newsletter h3 {
    margin-top: 0;
    margin-bottom: 0.5rem;
    color: var(--heading);
}

.smarkdown-newsletter p {
    color: var(--muted);
    font-size: 0.95rem;
    margin-top: 0;
    margin-bottom: 1.25rem;
}

.smarkdown-newsletter-form {
    display: flex;
    gap: 0.75rem;
}

.smarkdown-newsletter-input {
    flex-grow: 1;
    padding: 0.6rem 1rem;
    border: 1px solid var(--line);
    border-radius: 8px;
    background: var(--bg);
    color: var(--text);
    font-family: inherit;
    font-size: 0.95rem;
    transition: border-color 0.2s;
}

.smarkdown-newsletter-input:focus {
    outline: none;
    border-color: var(--accent);
}

.smarkdown-newsletter-button {
    background: var(--accent);
    color: #ffffff; /* Contrast text */
    border: none;
    border-radius: 8px;
    padding: 0.6rem 1.25rem;
    font-weight: 600;
    cursor: pointer;
    font-family: inherit;
    transition: filter 0.2s, transform 0.1s;
}

.smarkdown-newsletter-button:hover {
    filter: brightness(1.1);
}

.smarkdown-newsletter-button:active {
    transform: scale(0.97);
}

.smarkdown-newsletter-message {
    margin-top: 0.75rem;
    font-size: 0.85rem;
    display: none;
}
.smarkdown-newsletter-message.success {
    display: block;
    color: #22c55e;
}
.smarkdown-newsletter-message.error {
    display: block;
    color: #ef4444;
}

@media (max-width: 480px) {
    .smarkdown-newsletter-form {
        flex-direction: column;
    }
}

/* --- Mobile Responsive Zero-JS Hamburger Menu --- */
.mobile-nav-toggle { display: none; }
.mobile-nav-toggle-label { display: none; cursor: pointer; vertical-align: middle; padding: 0.5rem; }
@media (max-width: 768px) {
    header, .site-header { display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between; }
    .mobile-nav-toggle-label { display: block; order: 99; }
    header nav, .site-header nav, .site-nav { display: none; width: 100%; margin-top: 1rem; order: 100; }
    .mobile-nav-toggle:checked ~ nav, .mobile-nav-toggle:checked ~ .site-nav { display: block; }
    header nav ul, .site-header nav ul, .site-nav > ul { flex-direction: column !important; align-items: stretch !important; }
    header nav li > ul, .site-header nav li > ul, .site-nav li > ul {
        position: static !important; opacity: 1 !important; visibility: visible !important;
        display: block !important; padding-left: 1rem !important; margin-left: 0 !important;
        box-shadow: none !important; background: transparent !important; border: none !important; width: 100% !important;
    }
    footer nav ul, .footer-nav ul { flex-wrap: wrap; justify-content: center; }
}