:root {
  --bg: #0f172a;
  --bg-alt: #1e293b;
  --card: #1e293b;
  --card-border: #334155;
  --text: #e2e8f0;
  --text-dim: #94a3b8;
  --accent: #38bdf8;
  --accent-2: #22d3ee;
  --radius: 14px;
  --shadow: 0 10px 30px -12px rgba(0, 0, 0, 0.5);
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: "Segoe UI", system-ui, -apple-system, Arial, sans-serif;
  background: radial-gradient(circle at top left, #1e293b, #0f172a 60%);
  color: var(--text);
  line-height: 1.6;
}

a { color: var(--accent); }

header.site-header {
  padding: 3rem 1.5rem 2rem;
  text-align: center;
}

header.site-header h1 {
  margin: 0 0 0.5rem;
  font-size: clamp(1.8rem, 4vw, 2.6rem);
  background: linear-gradient(90deg, var(--accent), var(--accent-2));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

header.site-header p {
  color: var(--text-dim);
  max-width: 640px;
  margin: 0 auto;
}

main {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 1.5rem 4rem;
}

.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 1.5rem;
}

.card {
  background: var(--card);
  border: 1px solid var(--card-border);
  border-radius: var(--radius);
  padding: 1.5rem;
  box-shadow: var(--shadow);
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  text-decoration: none;
  color: var(--text);
  transition: transform 0.2s ease, border-color 0.2s ease;
  position: relative;
}

.card:hover {
  transform: translateY(-4px);
  border-color: var(--accent);
}

.card .icon {
  font-size: 2rem;
}

.card h2 {
  margin: 0;
  font-size: 1.25rem;
}

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

.card .tag {
  align-self: flex-start;
  font-size: 0.75rem;
  padding: 0.15rem 0.6rem;
  border-radius: 999px;
  background: rgba(56, 189, 248, 0.15);
  color: var(--accent);
  border: 1px solid rgba(56, 189, 248, 0.4);
}

.card.disabled {
  opacity: 0.5;
  cursor: not-allowed;
  pointer-events: none;
}

.card.disabled .tag {
  background: rgba(148, 163, 184, 0.15);
  color: var(--text-dim);
  border-color: rgba(148, 163, 184, 0.4);
}

/* Guide pages */

.guide-header {
  padding: 2.5rem 260px 1.5rem 1.5rem;
  max-width: 900px;
}

.guide-header a.back {
  display: inline-block;
  margin-bottom: 1rem;
  color: var(--text-dim);
  text-decoration: none;
  font-size: 0.9rem;
}

.guide-header a.back:hover { color: var(--accent); }

.guide-header h1 {
  margin: 0 0 0.5rem;
  font-size: clamp(1.6rem, 3.5vw, 2.2rem);
}

.guide-header p.lead {
  color: var(--text-dim);
}

.guide-layout {
  display: flex;
  align-items: flex-start;
  max-width: 1160px;
  margin: 0 auto;
  padding: 0 1.5rem 4rem;
  gap: 2rem;
}

nav.toc {
  position: sticky;
  top: 1.5rem;
  flex: 0 0 200px;
  width: 200px;
  background: var(--card);
  border: 1px solid var(--card-border);
  border-radius: var(--radius);
  padding: 1rem 0.75rem;
}

nav.toc h3 {
  margin: 0 0 0.5rem 0.5rem;
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-dim);
}

nav.toc ol {
  list-style: none;
  margin: 0;
  padding: 0;
  counter-reset: toc-counter;
}

nav.toc li {
  counter-increment: toc-counter;
}

nav.toc a {
  display: block;
  padding: 0.4rem 0.5rem;
  border-radius: 8px;
  color: var(--text);
  text-decoration: none;
  font-size: 0.9rem;
  transition: background 0.15s ease, color 0.15s ease;
}

nav.toc a::before {
  content: counter(toc-counter) ". ";
  color: var(--accent);
  font-weight: 600;
}

nav.toc a:hover,
nav.toc a.active {
  background: rgba(56, 189, 248, 0.12);
  color: var(--accent);
}

article.guide {
  flex: 1 1 auto;
  min-width: 0;
  margin: 0;
  padding: 0;
}

article.guide section {
  background: var(--card);
  border: 1px solid var(--card-border);
  border-radius: var(--radius);
  padding: 1.75rem;
  margin-bottom: 1.75rem;
  box-shadow: var(--shadow);
  scroll-margin-top: 1.5rem;
}

article.guide h2 {
  color: var(--accent);
  margin-top: 0;
  border-bottom: 1px solid var(--card-border);
  padding-bottom: 0.5rem;
}

article.guide h3 {
  color: var(--accent-2);
}

figure {
  margin: 1.25rem 0;
  text-align: center;
}

figure img {
  max-width: 100%;
  border-radius: 10px;
  border: 1px solid var(--card-border);
  box-shadow: var(--shadow);
}

figure figcaption {
  color: var(--text-dim);
  font-size: 0.85rem;
  margin-top: 0.5rem;
}

.fig-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 1.25rem;
}

pre {
  background: #0b1120;
  border: 1px solid var(--card-border);
  border-radius: 10px;
  padding: 1rem;
  overflow-x: auto;
  font-size: 0.9rem;
}

code {
  font-family: "Cascadia Code", "Consolas", monospace;
}

table.results {
  width: 100%;
  border-collapse: collapse;
  margin: 1rem 0;
}

table.results th, table.results td {
  border: 1px solid var(--card-border);
  padding: 0.5rem 0.75rem;
  text-align: left;
}

table.results th {
  background: rgba(56, 189, 248, 0.1);
  color: var(--accent);
}

.note {
  border-left: 4px solid var(--accent);
  background: rgba(56, 189, 248, 0.08);
  padding: 0.75rem 1rem;
  border-radius: 0 8px 8px 0;
  margin: 1rem 0;
}

.note strong { color: var(--accent); }

.shortcut {
  display: inline-block;
  background: #0b1120;
  border: 1px solid var(--card-border);
  border-radius: 6px;
  padding: 0.1rem 0.5rem;
  font-family: "Cascadia Code", "Consolas", monospace;
  font-size: 0.9rem;
  color: var(--accent-2);
}

footer.site-footer {
  text-align: center;
  color: var(--text-dim);
  padding: 2rem 1.5rem;
  font-size: 0.85rem;
}