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

/* ── Typography & Colour ─────────────────────────────────────── */
:root {
  --font-body:   system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  --font-mono:   "SFMono-Regular", Consolas, "Liberation Mono", Menlo, monospace;
  --color-bg:       #ffffff;
  --color-text:     #222222;
  --color-muted:    #666666;
  --color-link:     #1a56a0;
  --color-link-hover: #0d3a73;
  --color-header-bg:  #1a1a2e;
  --color-header-fg:  #ffffff;
  --color-code-bg:    #f6f8fa;
  --color-code-border:#e1e4e8;
  --color-blockquote: #005f8c;
  --color-rule:       #e1e4e8;
  --max-width:    820px;
}

body {
  font-family: var(--font-body);
  font-size: 1.05rem;
  line-height: 1.75;
  color: var(--color-text);
  background: var(--color-bg);
}

/* ── Header ──────────────────────────────────────────────────── */
.site-header {
  background: var(--color-header-bg);
  color: var(--color-header-fg);
  padding: 0.75rem 1.5rem;
}
.site-header-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  display: flex;
  align-items: center;
  gap: 2rem;
}
.site-title {
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--color-header-fg);
  text-decoration: none;
  white-space: nowrap;
}
.site-title:hover { text-decoration: underline; }
nav { display: flex; gap: 1.25rem; }
nav a {
  color: #aac4e8;
  text-decoration: none;
  font-size: 0.95rem;
}
nav a:hover { color: #ffffff; text-decoration: underline; }

/* ── Main content wrapper ────────────────────────────────────── */
main {
  max-width: var(--max-width);
  margin: 2.5rem auto;
  padding: 0 1.5rem;
}

/* ── Article header ──────────────────────────────────────────── */
.post-meta {
  font-size: 0.88rem;
  color: var(--color-muted);
  margin-bottom: 2rem;
}
.post-meta .category {
  display: inline-block;
  background: #eef3fb;
  color: var(--color-link);
  padding: 0.15rem 0.55rem;
  border-radius: 3px;
  font-size: 0.82rem;
  margin-right: 0.4rem;
  text-decoration: none;
}
.post-meta .category:hover { background: #d8e6f8; }

/* ── Headings ────────────────────────────────────────────────── */
h1 { font-size: 2rem;   line-height: 1.25; margin-bottom: 0.4rem; }
h2 { font-size: 1.5rem; line-height: 1.3;  margin: 2rem 0 0.6rem; }
h3 { font-size: 1.2rem; line-height: 1.3;  margin: 1.6rem 0 0.5rem; }
h4 { font-size: 1.05rem; margin: 1.4rem 0 0.4rem; }

/* ── Body text ───────────────────────────────────────────────── */
p          { margin: 0.85rem 0; }
ul, ol     { margin: 0.85rem 0 0.85rem 2rem; }
li         { margin: 0.3rem 0; }
hr         { border: none; border-top: 1px solid var(--color-rule); margin: 2rem 0; }

/* ── Links ───────────────────────────────────────────────────── */
a          { color: var(--color-link); }
a:hover    { color: var(--color-link-hover); }

/* ── Code ────────────────────────────────────────────────────── */
code {
  font-family: var(--font-mono);
  font-size: 0.88em;
  background: var(--color-code-bg);
  border: 1px solid var(--color-code-border);
  padding: 0.1em 0.35em;
  border-radius: 3px;
}

pre {
  font-family: var(--font-mono);
  font-size: 0.88rem;
  background: var(--color-code-bg);
  border: 1px solid var(--color-code-border);
  border-left: 3px solid var(--color-link);
  border-radius: 4px;
  padding: 1.1rem 1.25rem;
  overflow-x: auto;
  line-height: 1.55;
  margin: 1.25rem 0;
}
pre code {
  background: none;
  border: none;
  padding: 0;
  font-size: inherit;
}

/* ── Blockquote ──────────────────────────────────────────────── */
blockquote {
  border-left: 4px solid var(--color-blockquote);
  margin: 1.5rem 0;
  padding: 0.6rem 1.2rem;
  color: #444;
  background: #f0f7fc;
  border-radius: 0 4px 4px 0;
}
blockquote p { margin: 0.4rem 0; }

/* ── Images ──────────────────────────────────────────────────── */
figure {
  margin: 1.75rem 0;
  text-align: center;
}
figure img {
  max-width: 100%;
  height: auto;
  border-radius: 4px;
  border: 1px solid var(--color-code-border);
}
figcaption {
  font-size: 0.88rem;
  color: var(--color-muted);
  margin-top: 0.5rem;
}

/* ── Tables ──────────────────────────────────────────────────── */
table {
  width: 100%;
  border-collapse: collapse;
  margin: 1.5rem 0;
  font-size: 0.95rem;
}
th, td {
  border: 1px solid var(--color-code-border);
  padding: 0.5rem 0.75rem;
  text-align: left;
}
th { background: var(--color-code-bg); font-weight: 600; }
tr:nth-child(even) td { background: #fafafa; }

/* ── Category TOC (tutorial-archive page) ──────────────────────────────── */
.cat-toc {
  list-style: none;
  margin: 1.25rem 0 2.5rem;
  padding: 0;
  border-left: 3px solid var(--color-rule);
  padding-left: 1rem;
}
.cat-toc li { margin: 0.3rem 0; }
.cat-toc a {
  color: var(--color-link);
  text-decoration: none;
  font-size: 0.95rem;
}
.cat-toc a:hover { text-decoration: underline; }
.cat-count { color: var(--color-muted); font-weight: normal; font-size: 0.85em; }

/* ── Post list (tutorial-archive page) ──────────────────────────────────── */
.post-list {
  list-style: disc;
  margin: 0.4rem 0 2rem 1.5rem;
  padding: 0;
}
.post-list li { margin: 0.2rem 0; font-size: 0.95rem; }
.post-list a { color: var(--color-link); text-decoration: none; }
.post-list a:hover { text-decoration: underline; }

/* ── Mobile ──────────────────────────────────────────────────── */
@media (max-width: 600px) {
  h1 { font-size: 1.5rem; }
  h2 { font-size: 1.25rem; }
  main { padding: 0 1rem; }
  pre  { font-size: 0.82rem; padding: 0.8rem 0.9rem; }
}

/* ── Footer ──────────────────────────────────────────────────── */
.site-footer {
  margin-top: 4rem;
  padding: 1.5rem;
  text-align: center;
  font-size: 0.82rem;
  color: #aaa;
  border-top: 1px solid var(--color-rule);
}