@import url('https://fonts.googleapis.com/css2?family=JetBrains+Mono:wght@400;700&family=Inter:wght@400;500;600&display=swap');

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

:root {
  --bg:        #0D1B2A;
  --bg2:       #111F2E;
  --bg3:       #162638;
  --border:    rgba(255,255,255,0.07);
  --border-hi: rgba(74,222,128,0.35);
  --text:      #E8EDF2;
  --text-2:    #94A3B8;
  --text-3:    #64748B;
  --text-4:    #475569;
  --green:     #4ADE80;
  --green-dim: rgba(74,222,128,0.12);
  --amber:     #F59E0B;
  --amber-dim: rgba(245,158,11,0.12);
  --blue:      #60A5FA;
  --blue-dim:  rgba(96,165,250,0.12);
  --coral:     #FB7185;
  --purple:    #A78BFA;
  --mono:      'JetBrains Mono', monospace;
  --sans:      'Inter', sans-serif;
  --radius:    10px;
}

html { scroll-behavior: smooth; }

body {
  font-family: var(--sans);
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* ── Navigation ── */
.nav {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(13,27,42,0.92);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
  padding: 0 40px;
  display: flex;
  align-items: center;
  gap: 8px;
  height: 54px;
}
.nav-brand {
  font-family: var(--mono);
  font-size: 13px;
  font-weight: 700;
  color: var(--green);
  text-decoration: none;
  margin-right: 16px;
  white-space: nowrap;
}
.nav-links {
  display: flex;
  gap: 4px;
  flex-wrap: wrap;
  list-style: none;
}
.nav-links a {
  font-size: 12px;
  color: var(--text-3);
  text-decoration: none;
  padding: 5px 10px;
  border-radius: 6px;
  transition: color 0.15s, background 0.15s;
  white-space: nowrap;
}
.nav-links a:hover,
.nav-links a.active {
  color: var(--text);
  background: var(--bg3);
}
.nav-links a.active {
  color: var(--green);
}

/* ── Page header (inner pages) ── */
.page-header {
  padding: 48px 40px 40px;
  border-bottom: 1px solid var(--border);
}
.page-header .eyebrow {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  margin-bottom: 14px;
}
.page-header h1 {
  font-family: var(--mono);
  font-size: clamp(24px, 3.5vw, 36px);
  font-weight: 700;
  color: #fff;
  line-height: 1.2;
  margin-bottom: 14px;
}
.page-header .intro {
  font-size: 16px;
  color: var(--text-2);
  max-width: 600px;
  line-height: 1.7;
}

/* ── Main content area ── */
main { flex: 1; padding: 48px 40px; max-width: 820px; }

/* ── Callout boxes ── */
.callout {
  border-radius: 8px;
  padding: 16px 20px;
  margin: 24px 0;
  border-left: 3px solid;
  display: flex;
  gap: 14px;
  align-items: flex-start;
}
.callout-dot {
  width: 22px;
  height: 22px;
  border-radius: 50%;
  flex-shrink: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 10px;
  font-weight: 700;
  margin-top: 1px;
}
.callout-body { flex: 1; font-size: 14px; line-height: 1.6; }
.callout-body strong { display: block; font-size: 13px; font-weight: 600; margin-bottom: 4px; }

.callout.everyone  { background: var(--green-dim); border-color: var(--green); }
.callout.everyone  .callout-dot { background: rgba(74,222,128,0.2); color: var(--green); }
.callout.everyone  .callout-body strong { color: var(--green); }

.callout.new-to-cs { background: var(--blue-dim); border-color: var(--blue); }
.callout.new-to-cs .callout-dot { background: rgba(96,165,250,0.2); color: var(--blue); }
.callout.new-to-cs .callout-body strong { color: var(--blue); }

.callout.extension { background: var(--amber-dim); border-color: var(--amber); }
.callout.extension .callout-dot { background: rgba(245,158,11,0.2); color: var(--amber); }
.callout.extension .callout-body strong { color: var(--amber); }

/* ── Content typography ── */
.content h2 {
  font-family: var(--mono);
  font-size: 18px;
  font-weight: 700;
  color: #fff;
  margin: 40px 0 16px;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--border);
}
.content h3 {
  font-size: 15px;
  font-weight: 600;
  color: var(--text);
  margin: 24px 0 10px;
}
.content p { font-size: 15px; color: var(--text-2); margin-bottom: 16px; line-height: 1.75; }
.content ul, .content ol {
  font-size: 15px;
  color: var(--text-2);
  margin: 0 0 16px 20px;
  line-height: 1.75;
}
.content li { margin-bottom: 6px; }
.content strong { color: var(--text); font-weight: 600; }
.content code {
  font-family: var(--mono);
  font-size: 13px;
  background: var(--bg3);
  color: var(--green);
  padding: 2px 7px;
  border-radius: 4px;
  border: 1px solid var(--border);
}

/* ── Code blocks ── */
.code-block {
  background: var(--bg2);
  border: 1px solid var(--border);
  border-radius: 8px;
  margin: 20px 0;
  overflow: hidden;
}
.code-block-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 10px 16px;
  border-bottom: 1px solid var(--border);
}
.code-block-lang {
  font-family: var(--mono);
  font-size: 11px;
  color: var(--text-4);
  letter-spacing: 0.08em;
}
.code-block pre {
  padding: 20px;
  overflow-x: auto;
  font-family: var(--mono);
  font-size: 13px;
  line-height: 1.7;
  color: var(--text-2);
}
.code-block pre .kw  { color: #C084FC; }
.code-block pre .fn  { color: #60A5FA; }
.code-block pre .str { color: #86EFAC; }
.code-block pre .cm  { color: #475569; font-style: italic; }
.code-block pre .num { color: #FCA5A5; }

/* ── Trinket embed ── */
.trinket-wrap {
  border-radius: 8px;
  overflow: hidden;
  border: 1px solid var(--border);
  margin: 20px 0;
}
.trinket-wrap iframe { display: block; width: 100%; }

/* ── Checklist ── */
.checklist {
  background: var(--bg2);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px;
  margin-top: 40px;
}
.checklist h3 {
  font-family: var(--mono);
  font-size: 13px;
  color: var(--green);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  margin-bottom: 16px;
}
.checklist label {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  font-size: 14px;
  color: var(--text-2);
  margin-bottom: 12px;
  cursor: pointer;
  line-height: 1.5;
}
.checklist label:last-child { margin-bottom: 0; }
.checklist input[type="checkbox"] {
  width: 18px;
  height: 18px;
  margin-top: 1px;
  accent-color: var(--green);
  flex-shrink: 0;
  cursor: pointer;
}

/* ── Page nav (prev / next) ── */
.page-nav {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  padding: 32px 40px 48px;
  border-top: 1px solid var(--border);
  margin-top: auto;
}
.page-nav a {
  display: flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
  color: var(--text-3);
  font-size: 13px;
  padding: 12px 18px;
  border: 1px solid var(--border);
  border-radius: 8px;
  transition: border-color 0.2s, color 0.2s;
  max-width: 240px;
}
.page-nav a:hover { border-color: var(--border-hi); color: var(--green); }
.page-nav .pn-label { font-size: 11px; color: var(--text-4); display: block; margin-bottom: 2px; font-family: var(--mono); }
.page-nav .pn-title { font-weight: 500; color: var(--text); font-size: 13px; }
.page-nav a:hover .pn-title { color: var(--green); }
.page-nav .spacer { flex: 1; }

/* ── Footer ── */
footer {
  border-top: 1px solid var(--border);
  padding: 20px 40px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 12px;
}
footer p { font-size: 12px; color: var(--text-4); }
.footer-links { display: flex; gap: 20px; }
.footer-links a { font-size: 12px; color: var(--text-4); text-decoration: none; }
.footer-links a:hover { color: var(--text-2); }

/* ── Responsive ── */
@media (max-width: 640px) {
  .nav { padding: 0 20px; }
  .page-header, main { padding-left: 20px; padding-right: 20px; }
  .page-nav { padding: 24px 20px 36px; flex-direction: column; }
  footer { padding: 20px; }
}

@media (prefers-reduced-motion: reduce) {
  .cursor { animation: none; opacity: 1; }
  * { transition: none !important; }
}