/* Jigsaw documentation — static site for GitHub Pages */
:root {
  --bg: #0c1222;
  --bg-elevated: #121a2e;
  --surface: #1a2438;
  --border: #2a3754;
  --text: #e8edf7;
  --muted: #94a3b8;
  --accent: #38bdf8;
  --accent-dim: #0ea5e9;
  --success: #34d399;
  --warning: #fbbf24;
  --font-sans: "DM Sans", system-ui, -apple-system, sans-serif;
  --font-mono: "JetBrains Mono", ui-monospace, monospace;
  --radius: 12px;
  --shadow: 0 24px 48px rgba(0, 0, 0, 0.35);
  --max: 52rem;
}

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

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-height: 100vh;
  font-family: var(--font-sans);
  font-size: 1.05rem;
  line-height: 1.65;
  color: var(--text);
  background: var(--bg);
  background-image:
    radial-gradient(ellipse 80% 50% at 50% -20%, rgba(56, 189, 248, 0.18), transparent),
    radial-gradient(ellipse 60% 40% at 100% 0%, rgba(14, 165, 233, 0.1), transparent);
}

a {
  color: var(--accent);
  text-decoration-thickness: 1px;
  text-underline-offset: 3px;
}

a:hover {
  color: #7dd3fc;
}

code,
kbd {
  font-family: var(--font-mono);
  font-size: 0.9em;
  background: var(--surface);
  border: 1px solid var(--border);
  padding: 0.15em 0.45em;
  border-radius: 6px;
}

pre {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  line-height: 1.5;
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1rem 1.15rem;
  overflow-x: auto;
  box-shadow: var(--shadow);
}

pre code {
  background: none;
  border: none;
  padding: 0;
  font-size: inherit;
}

.wrap {
  width: min(100% - 2rem, var(--max));
  margin-inline: auto;
}

/* Header */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  backdrop-filter: blur(12px);
  background: rgba(12, 18, 34, 0.85);
  border-bottom: 1px solid var(--border);
}

.site-header .inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 0.85rem 0;
  flex-wrap: wrap;
}

.brand {
  display: flex;
  align-items: center;
  gap: 0.65rem;
  font-weight: 700;
  font-size: 1.15rem;
  color: var(--text);
  text-decoration: none;
}

.brand:hover {
  color: var(--accent);
}

.brand-mark {
  width: 2rem;
  height: 2rem;
  border-radius: 8px;
  background: linear-gradient(135deg, var(--accent), var(--accent-dim));
  display: grid;
  place-items: center;
  font-size: 1rem;
  color: var(--bg);
  font-weight: 800;
}

nav.nav-main {
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem 1rem;
  align-items: center;
}

nav.nav-main a {
  color: var(--muted);
  text-decoration: none;
  font-size: 0.95rem;
}

nav.nav-main a:hover,
nav.nav-main a[aria-current="page"] {
  color: var(--accent);
}

/* Hero */
.hero {
  padding: 3rem 0 2.5rem;
}

.hero h1 {
  font-size: clamp(2rem, 4vw, 2.75rem);
  line-height: 1.15;
  margin: 0 0 1rem;
  letter-spacing: -0.02em;
}

.lead {
  font-size: 1.2rem;
  color: var(--muted);
  max-width: 40ch;
  margin: 0 0 1.5rem;
}

/* Cards grid */
.grid-cards {
  display: grid;
  gap: 1rem;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  margin: 2rem 0;
}

.card {
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.25rem 1.35rem;
  transition: border-color 0.15s, transform 0.15s;
}

.card:hover {
  border-color: rgba(56, 189, 248, 0.35);
  transform: translateY(-2px);
}

.card h2 {
  margin: 0 0 0.5rem;
  font-size: 1.1rem;
}

.card p {
  margin: 0;
  color: var(--muted);
  font-size: 0.95rem;
}

.card a.stretched {
  color: inherit;
  text-decoration: none;
  display: block;
}

.card a.stretched:hover h2 {
  color: var(--accent);
}

/* Content pages */
main.content {
  padding: 2rem 0 4rem;
}

.content h1 {
  margin-top: 0;
  font-size: 2rem;
  letter-spacing: -0.02em;
}

.content h2 {
  margin-top: 2.25rem;
  padding-top: 0.5rem;
  border-top: 1px solid var(--border);
  font-size: 1.35rem;
}

.content h2:first-of-type {
  border-top: none;
  padding-top: 0;
  margin-top: 1.5rem;
}

.content h3 {
  font-size: 1.1rem;
  color: var(--muted);
  font-weight: 600;
}

.toc {
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1rem 1.25rem;
  margin: 1.5rem 0;
}

.toc strong {
  display: block;
  margin-bottom: 0.5rem;
  color: var(--muted);
  font-size: 0.85rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
}

.toc ul {
  margin: 0;
  padding-left: 1.2rem;
}

.note {
  border-left: 3px solid var(--accent);
  padding: 0.75rem 1rem;
  margin: 1.25rem 0;
  background: rgba(56, 189, 248, 0.08);
  border-radius: 0 var(--radius) var(--radius) 0;
}

.note.warn {
  border-color: var(--warning);
  background: rgba(251, 191, 36, 0.08);
}

table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.95rem;
  margin: 1rem 0;
}

th,
td {
  border: 1px solid var(--border);
  padding: 0.6rem 0.75rem;
  text-align: left;
}

th {
  background: var(--bg-elevated);
  color: var(--muted);
  font-weight: 600;
}

tr:nth-child(even) td {
  background: rgba(26, 36, 56, 0.4);
}

.site-footer {
  border-top: 1px solid var(--border);
  padding: 2rem 0;
  color: var(--muted);
  font-size: 0.9rem;
}

.site-footer a {
  color: var(--muted);
}

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

.copy-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  align-items: stretch;
  margin: 0.75rem 0 1.5rem;
}

.copy-row pre {
  flex: 1;
  min-width: min(100%, 280px);
  margin: 0;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.5rem 1rem;
  background: var(--accent);
  color: var(--bg) !important;
  font-weight: 600;
  border: none;
  border-radius: 8px;
  cursor: pointer;
  font-family: inherit;
  font-size: 0.9rem;
  text-decoration: none;
  flex-shrink: 0;
}

.btn:hover {
  filter: brightness(1.08);
}

.diagram {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  line-height: 1.45;
  white-space: pre;
  overflow-x: auto;
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1rem 1.25rem;
  color: var(--muted);
}

@media (max-width: 640px) {
  .copy-row {
    flex-direction: column;
  }
}