:root {
    --bg: #ffffff;
    --bg-soft: #f6f8fa;
    --text: #1b1f24;
    --text-muted: #5b6470;
    --border: #e3e7eb;
    --accent: #0b6bcb;
    --accent-soft: #e6f0fb;
    --warning: #b45309;
    --warning-soft: #fef3c7;
    --radius: 10px;
    --font: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    --mono: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
    --max: 1120px;
    --narrow: 760px;
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
body {
    margin: 0;
    font-family: var(--font);
    font-size: 17px;
    line-height: 1.65;
    color: var(--text);
    background: var(--bg);
}
img { max-width: 100%; height: auto; display: block; }
a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }
h1, h2, h3, h4 { line-height: 1.25; margin: 0 0 .5em; letter-spacing: -0.01em; }
h1 { font-size: clamp(1.9rem, 3.5vw, 2.6rem); }
h2 { font-size: clamp(1.4rem, 2.5vw, 1.8rem); }
h3 { font-size: 1.15rem; }
p { margin: 0 0 1em; }
.muted { color: var(--text-muted); }
.small { font-size: .875rem; }
.lead { font-size: 1.15rem; color: var(--text-muted); max-width: 46em; }

.container { width: 100%; max-width: var(--max); margin: 0 auto; padding: 0 20px; }
.container.narrow { max-width: var(--narrow); }
.section { padding: 40px 0; }
.section-head { display: flex; align-items: baseline; justify-content: space-between; gap: 16px; margin-bottom: 20px; }
.section-head h2 { margin: 0; }

.skip-link { position: absolute; left: -999px; top: 8px; background: var(--accent); color: #fff; padding: 8px 12px; border-radius: 6px; z-index: 100; }
.skip-link:focus { left: 8px; }

/* Header */
.site-header { border-bottom: 1px solid var(--border); background: var(--bg); position: sticky; top: 0; z-index: 50; }
.header-inner { display: flex; align-items: center; justify-content: space-between; gap: 24px; height: 62px; }
.header-end { display: flex; align-items: center; gap: 16px; }
.lang-switch { position: relative; }
.lang-switch summary { list-style: none; cursor: pointer; font-size: 13px; font-weight: 700; color: var(--text); padding: 6px 10px; border-radius: 6px; background: var(--bg-soft); border: 1px solid var(--border); }
.lang-switch summary::-webkit-details-marker { display: none; }
.lang-switch summary::after { content: ""; display: inline-block; margin-inline-start: 8px; border: 4px solid transparent; border-top-color: currentColor; vertical-align: 2px; }
.lang-switch[open] summary::after { border-top-color: transparent; border-bottom-color: currentColor; vertical-align: 4px; }
.lang-menu { position: absolute; inset-inline-end: 0; top: calc(100% + 6px); z-index: 30; min-width: 12rem; max-height: 20rem; overflow: auto; padding: 6px; background: var(--bg); border: 1px solid var(--border); border-radius: 10px; box-shadow: 0 16px 40px -24px rgba(15, 23, 42, .45); }
.lang-menu a { display: block; color: var(--text-muted); font-size: 14px; font-weight: 600; padding: 7px 10px; border-radius: 6px; }
.lang-menu a.active { color: var(--text); background: var(--bg-soft); }
.lang-menu a:hover { text-decoration: none; color: var(--text); background: var(--bg-soft); }
[dir="rtl"] .post-answer { border-left: 0; border-right: 3px solid var(--accent); padding-left: 0; padding-right: 16px; }
[dir="rtl"] .prose blockquote { border-left: 0; border-right: 4px solid var(--border); }
[dir="rtl"] .prose ul, [dir="rtl"] .prose ol, [dir="rtl"] .takeaways ul { padding-left: 0; padding-right: 1.4em; }
.brand { font-weight: 700; font-size: 1.15rem; color: var(--text); }
.brand:hover { text-decoration: none; }
.site-nav { display: flex; gap: 6px; flex-wrap: wrap; }
.site-nav a { color: var(--text-muted); padding: 6px 12px; border-radius: 6px; font-weight: 500; }
.site-nav a:hover, .site-nav a.active { color: var(--text); background: var(--bg-soft); text-decoration: none; }

/* Hero */
.hero { padding: 56px 0 32px; background: linear-gradient(180deg, var(--bg-soft), var(--bg)); border-bottom: 1px solid var(--border); }
.hero h1 { margin-bottom: .3em; }

/* Pills */
.pill-row { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 16px; }
.pill { display: inline-block; font-size: .8rem; font-weight: 600; padding: 3px 10px; border-radius: 999px; background: var(--bg-soft); color: var(--text-muted); border: 1px solid var(--border); }
.pill:hover { text-decoration: none; color: var(--text); border-color: #cfd6dd; }
.pill-accent { background: var(--accent-soft); color: var(--accent); border-color: transparent; }
.pill-warning { background: var(--warning-soft); color: var(--warning); border-color: transparent; }

/* Cards */
.grid { display: grid; gap: 24px; }
.grid-2 { grid-template-columns: repeat(2, 1fr); }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-4 { grid-template-columns: repeat(4, 1fr); }
.card { display: flex; flex-direction: column; border: 1px solid var(--border); border-radius: var(--radius); overflow: hidden; background: var(--bg); transition: box-shadow .15s ease, transform .15s ease; }
.card:hover { box-shadow: 0 6px 24px rgba(20, 30, 40, .08); transform: translateY(-2px); }
.card-media img { aspect-ratio: 16 / 9; object-fit: cover; width: 100%; }
.card-body { padding: 18px 18px 16px; display: flex; flex-direction: column; gap: 8px; flex: 1; }
.card-meta { display: flex; flex-wrap: wrap; align-items: center; gap: 8px; font-size: .8rem; color: var(--text-muted); }
.card-title { margin: 0; font-size: 1.1rem; }
.card-title a { color: var(--text); }
.card-excerpt { margin: 0; color: var(--text-muted); font-size: .95rem; }
.card-footer { margin-top: auto; padding-top: 6px; }

/* Breadcrumbs */
.breadcrumbs { font-size: .85rem; color: var(--text-muted); margin-bottom: 18px; display: flex; flex-wrap: wrap; gap: 6px; }
.breadcrumbs .sep { opacity: .5; }

/* Post */
.post-header { padding: 40px 0 8px; }
.post-answer { color: var(--text); font-size: 1.2rem; border-left: 3px solid var(--accent); padding-left: 16px; margin: 20px 0; }
.post-byline { display: flex; flex-wrap: wrap; align-items: center; gap: 8px; color: var(--text-muted); font-size: .9rem; margin-top: 8px; }
.post-byline .sep { opacity: .5; }
.avatar { width: 40px; height: 40px; border-radius: 50%; object-fit: cover; }
.avatar.large { width: 72px; height: 72px; }
.post-cover { margin: 24px 0 0; }
.post-cover img { border-radius: var(--radius); width: 100%; aspect-ratio: 1200 / 630; object-fit: cover; }
.post-tags { margin: 28px 0; }

/* Prose */
.prose { margin-top: 32px; font-size: 1.05rem; }
.prose > * + * { margin-top: 1.1em; }
.prose h2 { margin-top: 2em; font-size: 1.55rem; }
.prose h3 { margin-top: 1.6em; font-size: 1.25rem; }
.prose h2 .heading-anchor, .prose h3 .heading-anchor { opacity: 0; margin-left: .35em; font-weight: 400; color: var(--text-muted); font-size: .8em; }
.prose h2:hover .heading-anchor, .prose h3:hover .heading-anchor { opacity: 1; text-decoration: none; }
.prose img { border-radius: 8px; margin: 1.5em auto; }
.prose blockquote { margin: 1.5em 0; padding: 4px 20px; border-left: 4px solid var(--border); color: var(--text-muted); }
.prose ul, .prose ol { padding-left: 1.4em; }
.prose li + li { margin-top: .35em; }
.prose code { font-family: var(--mono); font-size: .9em; background: var(--bg-soft); padding: 2px 6px; border-radius: 4px; }
.prose pre { background: #0f172a; color: #e2e8f0; padding: 16px 20px; border-radius: 8px; overflow-x: auto; font-size: .9rem; }
.prose pre code { background: none; padding: 0; color: inherit; }
.prose table { width: 100%; border-collapse: collapse; font-size: .95rem; display: block; overflow-x: auto; }
.prose th, .prose td { border: 1px solid var(--border); padding: 8px 12px; text-align: left; vertical-align: top; }
.prose th { background: var(--bg-soft); font-weight: 600; }
.prose hr { border: 0; border-top: 1px solid var(--border); margin: 2.5em 0; }

/* Takeaways */
.takeaways { margin: 40px 0; padding: 22px 26px; background: var(--accent-soft); border-radius: var(--radius); }
.takeaways h2 { font-size: 1.1rem; margin-bottom: .6em; color: var(--accent); }
.takeaways ul { margin: 0; padding-left: 1.2em; }
.takeaways li + li { margin-top: .4em; }

/* Author */
.author-box { display: flex; gap: 20px; align-items: flex-start; padding: 24px; border: 1px solid var(--border); border-radius: var(--radius); background: var(--bg-soft); margin: 32px 0; }
.author-box h3 { margin: 0 0 .2em; }
.author-box p { margin: 0 0 .5em; }
.author-page { background: none; border: 0; padding: 0; margin: 0; }
.author-page .avatar.large { width: 96px; height: 96px; }

/* Glossary */
.term-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; margin-top: 20px; }
.term-card { display: flex; flex-direction: column; gap: 8px; padding: 22px 24px; border: 1px solid var(--border); border-radius: var(--radius); color: var(--text); background: var(--bg); transition: box-shadow .15s ease, transform .15s ease, border-color .15s ease; }
.term-card:hover { text-decoration: none; border-color: #cfd6dd; box-shadow: 0 6px 24px rgba(20, 30, 40, .08); transform: translateY(-2px); }
.term-card h2 { font-size: 1.1rem; margin: 0; }
.term-card p { margin: 0; color: var(--text-muted); font-size: .95rem; flex: 1; }
.term-more { color: var(--accent); font-size: .875rem; font-weight: 600; }

/* Pagination */
.pagination { margin-top: 36px; }
.pager { display: flex; align-items: center; justify-content: space-between; gap: 16px; }
.pager-pages { display: flex; gap: 4px; }
.pager-pages a, .pager-pages .current, .pager-pages .dots { min-width: 36px; text-align: center; padding: 6px 8px; border-radius: 6px; }
.pager-pages .current { background: var(--accent); color: #fff; font-weight: 600; }
.pager-btn { padding: 6px 14px; border: 1px solid var(--border); border-radius: 6px; }
.pager-btn.disabled { color: var(--text-muted); opacity: .5; }

/* Footer */
.site-footer { border-top: 1px solid var(--border); background: var(--bg-soft); margin-top: 40px; padding: 36px 0; font-size: .95rem; }
.footer-inner { display: grid; gap: 20px; }
.footer-links { display: flex; flex-wrap: wrap; gap: 16px; }
.footer-links a { color: var(--text-muted); }

@media (max-width: 960px) {
    .grid-3, .grid-4, .term-grid { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 640px) {
    body { font-size: 16px; }
    .grid-2, .grid-3, .grid-4, .term-grid { grid-template-columns: 1fr; }
    .header-inner { height: auto; padding: 12px 0; flex-direction: column; align-items: flex-start; gap: 8px; }
    .header-end { width: 100%; justify-content: space-between; flex-wrap: wrap; }
    .section { padding: 28px 0; }
    .author-box { flex-direction: column; }
    .pager { flex-wrap: wrap; justify-content: center; }
}