/* ── Tokens ───────────────────────────────────────────────────────────────── */
:root {
  --text:        #0f172a;
  --text-muted:  #64748b;
  --text-light:  #94a3b8;
  --bg:          #ffffff;
  --bg-subtle:   #f8fafc;
  --border:      #e2e8f0;
  --accent:      #2563eb;
  --accent-hover:#1d4ed8;
  --tag-bg:      #eff6ff;
  --tag-hover:   #dbeafe;
  --max-w:       860px;
  --font-sans:   "Inter", -apple-system, BlinkMacSystemFont, system-ui, sans-serif;
  --font-serif:  "Lora", Georgia, "Times New Roman", serif;
  --font-mono:   "JetBrains Mono", "Fira Code", "Cascadia Code", "Courier New", monospace;
  --radius:      6px;
  --ease:        cubic-bezier(.4,0,.2,1);
  --t:           140ms;
}

/* ── Reset ────────────────────────────────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html { font-size: 17px; scroll-behavior: smooth; }

body {
  font-family: var(--font-sans);
  background: var(--bg);
  color: var(--text);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

img { max-width: 100%; height: auto; display: block; }
a { color: var(--accent); }
a:hover { color: var(--accent-hover); }

:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 3px;
  border-radius: 3px;
}

/* ── Skip link ────────────────────────────────────────────────────────────── */
.skip-link {
  position: fixed;
  top: 0;
  left: 0;
  transform: translateY(-100%);
  background: var(--accent);
  color: #fff;
  padding: .5rem 1rem;
  z-index: 100;
  border-radius: 0 0 4px 0;
  font-size: .875rem;
  text-decoration: none;
  transition: transform var(--t);
}
.skip-link:focus { transform: translateY(0); }

/* ── Layout ───────────────────────────────────────────────────────────────── */
.container {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 1.5rem;
}

/* ── Header ───────────────────────────────────────────────────────────────── */
.site-header {
  padding: 1.5rem 0;
  margin-bottom: 3.5rem;
  border-bottom: 1px solid var(--border);
}
.site-header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}
.site-title {
  font-weight: 700;
  font-size: .9375rem;
  text-decoration: none;
  color: var(--text);
  letter-spacing: -.02em;
  transition: color var(--t) var(--ease);
}
.site-title:hover { color: var(--accent); }

.site-header nav {
  display: flex;
  gap: 1.75rem;
  align-items: center;
}
.site-header nav a {
  color: var(--text-muted);
  text-decoration: none;
  font-size: .875rem;
  font-weight: 500;
  transition: color var(--t) var(--ease);
  position: relative;
}
.site-header nav a:hover { color: var(--text); }
.site-header nav a::after {
  content: '';
  position: absolute;
  bottom: -1px;
  left: 0;
  width: 0;
  height: 1px;
  background: var(--text);
  transition: width var(--t) var(--ease);
}
.site-header nav a:hover::after { width: 100%; }

/* ── Footer ───────────────────────────────────────────────────────────────── */
.site-footer {
  border-top: 1px solid var(--border);
  margin-top: 5rem;
  padding: 2rem 0;
  color: var(--text-muted);
  font-size: .825rem;
}
.site-footer .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: .75rem;
}
.site-footer nav { display: flex; gap: 1.25rem; }
.site-footer nav a {
  color: var(--text-muted);
  text-decoration: none;
  transition: color var(--t) var(--ease);
}
.site-footer nav a:hover { color: var(--text); }

/* ── Index layout ─────────────────────────────────────────────────────────── */
.index-layout {
  display: grid;
  grid-template-columns: 1fr;
  gap: 2.5rem;
  padding-bottom: 4rem;
  align-items: start;
}
@media (min-width: 680px) {
  .index-layout {
    grid-template-columns: 1fr 200px;
    gap: 3.5rem;
  }
}

/* ── Post list ────────────────────────────────────────────────────────────── */
.posts-list {
  display: flex;
  flex-direction: column;
}

.post-card {
  display: flex;
  flex-direction: column;
  gap: .6rem;
  padding: 2rem 0;
  border-bottom: 1px solid var(--border);
}
.post-card:first-child { padding-top: 0; }
.post-card:last-child { border-bottom: none; }

.post-card__cover {
  width: 100%;
  aspect-ratio: 16 / 7;
  object-fit: cover;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  margin-bottom: .5rem;
  transition: opacity var(--t) var(--ease);
}
.post-card__cover:hover { opacity: .92; }

.post-card__meta {
  display: flex;
  align-items: center;
  gap: .5rem;
  flex-wrap: wrap;
  font-size: .775rem;
  color: var(--text-light);
  letter-spacing: .01em;
}

.post-card__title {
  font-size: 1.2rem;
  line-height: 1.3;
  font-weight: 700;
  letter-spacing: -.025em;
}
.post-card__title a {
  text-decoration: none;
  color: var(--text);
  transition: color var(--t) var(--ease);
}
.post-card__title a:hover { color: var(--accent); }

.post-card__excerpt {
  color: var(--text-muted);
  font-size: .9375rem;
  line-height: 1.65;
}

.read-more {
  display: inline-flex;
  align-items: center;
  gap: .3rem;
  font-size: .8125rem;
  font-weight: 600;
  text-decoration: none;
  color: var(--accent);
  margin-top: .15rem;
  transition: gap var(--t) var(--ease);
}
.read-more:hover { gap: .5rem; color: var(--accent-hover); }

/* ── Sidebar ──────────────────────────────────────────────────────────────── */
.tag-sidebar {
  padding-top: .25rem;
  position: sticky;
  top: 2rem;
}
.sidebar__heading {
  font-size: .7rem;
  text-transform: uppercase;
  letter-spacing: .1em;
  color: var(--text-light);
  margin-bottom: 1rem;
  font-weight: 600;
}
.tag-list {
  display: flex;
  flex-direction: column;
  gap: .4rem;
}

/* ── Tags ─────────────────────────────────────────────────────────────────── */
.tag {
  display: inline-flex;
  align-items: center;
  background: var(--tag-bg);
  color: var(--accent);
  font-size: .7rem;
  font-weight: 600;
  padding: .22em .75em;
  border-radius: 999px;
  text-decoration: none;
  letter-spacing: .01em;
  line-height: 1.6;
  transition: background var(--t) var(--ease), color var(--t) var(--ease);
}
.tag:hover { background: var(--tag-hover); color: var(--accent-hover); }
.tag--large { font-size: .8125rem; }
.tag--active { background: var(--accent); color: #fff; }
.tag--active:hover { background: var(--accent-hover); color: #fff; }

/* ── Tag header ───────────────────────────────────────────────────────────── */
.tag-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: .75rem;
  margin-bottom: 2rem;
}
.tag-header h1 {
  font-size: 1.5rem;
  font-weight: 700;
  letter-spacing: -.025em;
}

/* ── Pagination ───────────────────────────────────────────────────────────── */
.pagination {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: 2rem;
  font-size: .875rem;
}
.pagination__info { color: var(--text-muted); }
.pagination__link { text-decoration: none; font-weight: 600; }
.pagination__link:hover { text-decoration: underline; }

/* ── Empty state ──────────────────────────────────────────────────────────── */
.empty-state {
  color: var(--text-muted);
  font-size: .9375rem;
  padding: 3rem 0;
  text-align: center;
}

/* ── Single post ──────────────────────────────────────────────────────────── */
.post {
  max-width: 680px;
  padding-bottom: 5rem;
}
.post__header { margin-bottom: 2.5rem; }
.post__meta {
  display: flex;
  align-items: center;
  gap: .6rem;
  flex-wrap: wrap;
  font-size: .775rem;
  color: var(--text-light);
  letter-spacing: .01em;
  margin-bottom: 1.1rem;
}
.post__tags { display: flex; gap: .35rem; flex-wrap: wrap; }
.post__title {
  font-size: clamp(1.75rem, 5vw, 2.5rem);
  line-height: 1.2;
  font-weight: 700;
  letter-spacing: -.035em;
  color: var(--text);
}
.post__cover {
  margin-bottom: 3rem;
  border-radius: 10px;
  overflow: hidden;
  border: 1px solid var(--border);
}
.post__cover img {
  width: 100%;
  max-height: 460px;
  object-fit: cover;
}
.post__footer {
  margin-top: 3.5rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--border);
}

/* ── Back link ────────────────────────────────────────────────────────────── */
.back-link {
  font-size: .875rem;
  text-decoration: none;
  color: var(--text-muted);
  transition: color var(--t) var(--ease);
}
.back-link:hover { color: var(--text); }

/* ── About page ───────────────────────────────────────────────────────────── */
.about-page {
  max-width: 660px;
  padding-bottom: 5rem;
}
.about-header {
  display: flex;
  align-items: center;
  gap: 1.5rem;
  margin-bottom: 2.75rem;
  padding-bottom: 2rem;
  border-bottom: 1px solid var(--border);
}
.about-avatar {
  width: 68px;
  height: 68px;
  flex-shrink: 0;
  border-radius: 50%;
  background: var(--tag-bg);
  border: 2px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.6rem;
  font-weight: 700;
  color: var(--accent);
  font-family: var(--font-sans);
  user-select: none;
}
.about-name {
  font-size: 1.6rem;
  font-weight: 700;
  letter-spacing: -.03em;
  line-height: 1.2;
}

/* ── Prose (rendered markdown) ────────────────────────────────────────────── */
.prose {
  font-family: var(--font-serif);
  font-size: 1.0625rem;
  line-height: 1.85;
  color: var(--text);
}
.prose > * + * { margin-top: 1.4em; }

.prose h1,
.prose h2,
.prose h3,
.prose h4 {
  font-family: var(--font-sans);
  font-weight: 700;
  line-height: 1.25;
  margin-top: 2.25em;
  margin-bottom: .5em;
  color: var(--text);
  letter-spacing: -.02em;
}
.prose h1 { font-size: 1.75rem; }
.prose h2 { font-size: 1.35rem; }
.prose h3 { font-size: 1.1rem; }
.prose h4 { font-size: 1rem; }

.prose a { color: var(--accent); text-underline-offset: 3px; }
.prose a:hover { color: var(--accent-hover); }
.prose strong { font-weight: 700; color: var(--text); }
.prose em { font-style: italic; }

.prose ul,
.prose ol { padding-left: 1.6em; }
.prose li + li { margin-top: .4em; }

.prose blockquote {
  border-left: 3px solid var(--accent);
  margin-left: 0;
  padding: .6em 1.25em;
  color: var(--text-muted);
  font-style: italic;
  background: var(--bg-subtle);
  border-radius: 0 var(--radius) var(--radius) 0;
}

.prose hr {
  border: none;
  border-top: 1px solid var(--border);
  margin: 2.75em 0;
}

.prose img {
  border-radius: var(--radius);
  border: 1px solid var(--border);
  margin: 1.75em auto;
}

.prose code {
  font-family: var(--font-mono);
  font-size: .82em;
  background: var(--bg-subtle);
  border: 1px solid var(--border);
  padding: .18em .45em;
  border-radius: 4px;
  color: #c7254e;
}

/* ── Code blocks (dark theme via pygments.css) ────────────────────────────── */
.prose .highlight {
  position: relative;
  border-radius: 10px;
  overflow: hidden;
  margin: 1.75em 0;
  box-shadow: 0 4px 24px rgba(0,0,0,.16), 0 1px 4px rgba(0,0,0,.1);
}
.prose .highlight pre {
  background: transparent;
  border: none;
  margin: 0;
  padding: 1.4em 1.6em;
  overflow-x: auto;
  font-size: .9rem;
  line-height: 1.7;
  font-weight: 400;
  -webkit-font-smoothing: subpixel-antialiased;
  -moz-osx-font-smoothing: auto;
}
.prose pre { font-size: .875rem; line-height: 1.65; }
.prose pre code { background: none; border: none; padding: 0; color: inherit; }

/* Copy button */
.prose .highlight .copy-btn {
  position: absolute;
  top: .65em;
  right: .65em;
  background: rgba(255,255,255,.08);
  border: 1px solid rgba(255,255,255,.14);
  color: rgba(255,255,255,.5);
  font-family: var(--font-sans);
  font-size: .68rem;
  font-weight: 500;
  padding: .28em .7em;
  border-radius: 4px;
  cursor: pointer;
  opacity: 0;
  transition: opacity var(--t), background var(--t);
  letter-spacing: .03em;
}
.prose .highlight:hover .copy-btn { opacity: 1; }
.prose .highlight .copy-btn:hover { background: rgba(255,255,255,.18); color: #fff; }
.prose .highlight .copy-btn.copied { color: #7ec8a4; border-color: #7ec8a4; }

/* ── Tables ───────────────────────────────────────────────────────────────── */
.prose table {
  width: 100%;
  border-collapse: collapse;
  font-size: .9rem;
  font-family: var(--font-sans);
}
.prose th {
  font-weight: 600;
  background: var(--bg-subtle);
  font-size: .8125rem;
  letter-spacing: .03em;
}
.prose th,
.prose td {
  padding: .55em .85em;
  border: 1px solid var(--border);
  text-align: left;
}

/* ── Heading permalinks ───────────────────────────────────────────────────── */
.prose .headerlink {
  opacity: 0;
  margin-left: .4em;
  font-size: .75em;
  text-decoration: none;
  transition: opacity var(--t);
  user-select: none;
}
.prose h1:hover .headerlink,
.prose h2:hover .headerlink,
.prose h3:hover .headerlink,
.prose h4:hover .headerlink { opacity: .35; }

/* ── Table of contents ────────────────────────────────────────────────────── */
.toc {
  background: var(--bg-subtle);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.1em 1.5em;
  font-family: var(--font-sans);
  font-size: .875rem;
}
.toc::before {
  content: 'Contents';
  font-weight: 700;
  display: block;
  margin-bottom: .6em;
  font-size: .8125rem;
  text-transform: uppercase;
  letter-spacing: .08em;
  color: var(--text-muted);
}

/* ── Quotes page ──────────────────────────────────────────────────────────── */
.quotes-page {
  max-width: 680px;
  padding-bottom: 5rem;
}
.quotes-header {
  margin-bottom: 3rem;
  padding-bottom: 2rem;
  border-bottom: 1px solid var(--border);
}
.quotes-header h1 {
  font-size: clamp(1.75rem, 5vw, 2.25rem);
  font-weight: 700;
  letter-spacing: -.035em;
  margin-bottom: .5rem;
}
.quotes-desc {
  color: var(--text-muted);
  font-size: .9375rem;
}
.quotes-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0;
}
.quote-card {
  padding: 2rem 0;
  border-bottom: 1px solid var(--border);
}
.quote-card:first-child { padding-top: 0; }
.quote-card:last-child { border-bottom: none; }
.quote-card__text {
  font-family: var(--font-serif);
  font-size: 1.0625rem;
  line-height: 1.75;
  color: var(--text);
  border: none;
  margin: 0 0 1rem;
  padding: 0;
  font-style: italic;
}
.quote-card__text::before { content: '\201C'; }
.quote-card__text::after  { content: '\201D'; }
.quote-card__footer {
  display: flex;
  align-items: baseline;
  gap: .5rem;
  flex-wrap: wrap;
  font-size: .8125rem;
  color: var(--text-muted);
}
.quote-card__author { font-weight: 600; color: var(--text); }
.quote-card__source::before { content: '·'; margin-right: .5rem; color: var(--border); }

/* ── TIL list page ────────────────────────────────────────────────────────── */
.til-list-page {
  max-width: 680px;
  padding-bottom: 5rem;
}
.til-list-header {
  margin-bottom: 3rem;
  padding-bottom: 2rem;
  border-bottom: 1px solid var(--border);
}
.til-list-header h1 {
  font-size: clamp(1.75rem, 5vw, 2.25rem);
  font-weight: 700;
  letter-spacing: -.035em;
  margin-bottom: .5rem;
}
.til-list-desc {
  color: var(--text-muted);
  font-size: .9375rem;
}
.til-topic-group {
  margin-bottom: 2.75rem;
}
.til-topic-heading {
  font-size: .75rem;
  text-transform: uppercase;
  letter-spacing: .1em;
  font-weight: 700;
  color: var(--text-light);
  margin-bottom: 1rem;
}
.til-entries {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: .1rem;
}
.til-entry {
  display: grid;
  grid-template-columns: 7rem 1fr;
  gap: .75rem;
  align-items: baseline;
  padding: .45rem 0;
  border-bottom: 1px solid var(--border);
}
.til-entry:last-child { border-bottom: none; }
.til-entry__date {
  font-size: .775rem;
  color: var(--text-light);
  white-space: nowrap;
  letter-spacing: .01em;
}
.til-entry__title {
  font-size: .9375rem;
  font-weight: 500;
  text-decoration: none;
  color: var(--text);
  transition: color var(--t) var(--ease);
}
.til-entry__title:hover { color: var(--accent); }

/* ── TIL single post ──────────────────────────────────────────────────────── */
.til-post {
  max-width: 680px;
  padding-bottom: 5rem;
}
.til-post__header { margin-bottom: 2rem; }
.til-post__meta {
  display: flex;
  align-items: center;
  gap: .5rem;
  flex-wrap: wrap;
  font-size: .775rem;
  color: var(--text-light);
  margin-bottom: 1rem;
}
.til-post__sep { color: var(--border); }
.til-post__title {
  font-size: clamp(1.5rem, 4vw, 2rem);
  line-height: 1.25;
  font-weight: 700;
  letter-spacing: -.03em;
  color: var(--text);
}
.til-post__body { margin-top: 2rem; }
.til-post__footer {
  margin-top: 3rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--border);
}

/* ── Responsive ───────────────────────────────────────────────────────────── */
@media (max-width: 640px) {
  html { font-size: 16px; }
  .post__title { font-size: 1.6rem; }
  .site-header { margin-bottom: 2.5rem; }
  .about-header { flex-direction: column; align-items: flex-start; gap: 1rem; }
}