:root {
  --bg: #ffffff;
  --panel: #f8fafc;
  --panel-2: #f1f5f9;
  --text: #0f172a;
  --muted: #475569;
  --border: #e2e8f0;
  --accent: #2563eb;
  --accent-hover: #1d4ed8;
  --accent-2: #16a34a;
  --danger: #ef4444;
  --focus: rgba(37, 99, 235, 0.5);
  --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
  --shadow: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
  --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
  --max: 1024px;
  --radius: 8px;
}

* { box-sizing: border-box; }

html, body {
  height: 100%;
}

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans", sans-serif, "Apple Color Emoji", "Segoe UI Emoji", "Segoe UI Symbol", "Noto Color Emoji";
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

a {
  color: var(--accent);
  text-decoration: none;
  font-weight: 500;
  transition: color 0.2s;
}

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

.skip-link {
  position: absolute;
  left: -9999px;
  top: auto;
  width: 1px;
  height: 1px;
  overflow: hidden;
}

.skip-link:focus {
  left: 16px;
  top: 12px;
  width: auto;
  height: auto;
  padding: 12px 16px;
  background: white;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow-lg);
  outline: 2px solid var(--accent);
  z-index: 1000;
  font-weight: 600;
  color: var(--text);
}

.container {
  max-width: var(--max);
  margin: 0 auto;
  padding: 0 24px;
}

header {
  position: sticky;
  top: 0;
  background: rgba(255, 255, 255, 0.9);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--border);
  z-index: 50;
}

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  height: 64px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  font-weight: 700;
  font-size: 1.125rem;
  color: var(--text);
}

.brand-mark {
  width: 32px;
  height: 32px;
  border-radius: 8px;
  background: linear-gradient(135deg, var(--accent), var(--accent-hover));
  box-shadow: var(--shadow-sm);
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 8px;
}

.nav-links a {
  padding: 8px 12px;
  border-radius: 6px;
  color: var(--muted);
  font-size: 0.9375rem;
  font-weight: 500;
  transition: all 0.2s;
}

.nav-links a:hover {
  color: var(--text);
  background: var(--panel-2);
}

.nav-links a[aria-current="page"] {
  color: var(--accent);
  background: rgba(37, 99, 235, 0.08);
}

main {
  padding: 48px 0 80px;
}

.content-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 300px;
  gap: 48px;
  align-items: start;
}

@media (max-width: 900px) {
  .content-grid {
    grid-template-columns: 1fr;
    gap: 32px;
  }
}

.prose {
  max-width: 65ch;
  font-size: 1.0625rem;
}

.prose h2 {
  margin-top: 2.5rem;
  font-size: 1.75rem;
  color: var(--text);
  letter-spacing: -0.025em;
}

.prose h3 {
  margin-top: 2rem;
  font-size: 1.25rem;
  color: var(--text);
}

.prose p {
  color: var(--muted);
  margin-bottom: 1.25rem;
}

.prose ul,
.prose ol {
  margin: 0 0 1.25rem;
  padding-left: 1.5rem;
  color: var(--muted);
}

.prose li {
  margin: 0.5rem 0;
  padding-left: 0.5rem;
}

.quote {
  border-left: 4px solid var(--accent);
  padding: 1.25rem 1.5rem;
  border-radius: 0 var(--radius) var(--radius) 0;
  background: var(--panel-2);
  color: var(--text);
  font-style: italic;
  margin: 2rem 0;
}

.toc {
  position: sticky;
  top: 88px;
}

.toc h2 {
  font-size: 0.875rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--muted);
  margin-bottom: 12px;
}

.toc-link {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 10px 12px;
  border-radius: 6px;
  color: var(--muted);
  font-weight: 500;
  border: 1px solid transparent;
  transition: all 0.2s;
}

.toc-link:hover {
  background: var(--panel-2);
  color: var(--text);
  border-color: var(--border);
  text-decoration: none;
}

.toc-link .icon {
  font-size: 1.25rem;
  line-height: 1;
}

.full-width {
  width: 100%;
  display: flex;
}

.hero {
  display: grid;
  grid-template-columns: 1.25fr 0.75fr;
  gap: 48px;
  align-items: center;
  padding: 48px 0;
  border-bottom: 1px solid var(--border);
  margin-bottom: 48px;
}

.hero.compact {
  grid-template-columns: 1fr;
  padding: 32px 0;
  gap: 24px;
}

@media (max-width: 900px) {
  .hero {
    grid-template-columns: 1fr;
    gap: 32px;
    padding: 32px 0;
  }
}

.kicker {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 0.875rem;
  color: var(--accent);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: 16px;
}

h1 {
  font-size: clamp(2.5rem, 4vw, 3.5rem);
  line-height: 1.1;
  font-weight: 800;
  letter-spacing: -0.025em;
  color: var(--text);
  margin: 0 0 24px;
}

h1 + p {
  font-size: 1.25rem;
  line-height: 1.6;
  color: var(--muted);
  max-width: 60ch;
  margin-bottom: 32px;
}

.btn-row {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 24px;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 10px 20px;
  border-radius: 6px;
  border: 1px solid var(--border);
  background: white;
  color: var(--text);
  font-weight: 600;
  font-size: 0.9375rem;
  cursor: pointer;
  transition: all 0.2s;
  box-shadow: var(--shadow-sm);
  text-decoration: none;
}

.btn:hover {
  border-color: #cbd5e1;
  background: #f8fafc;
  transform: translateY(-1px);
  box-shadow: var(--shadow);
  color: var(--text);
}

.btn.primary {
  background: var(--accent);
  border-color: var(--accent);
  color: white;
}

.btn.primary:hover {
  background: var(--accent-hover);
  border-color: var(--accent-hover);
  color: white;
}

.btn:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

.panel {
  background: var(--panel);
  border-radius: 12px;
  padding: 32px;
}

.panel h2 {
  font-size: 1.5rem;
  margin: 0 0 16px;
  color: var(--text);
}

.stack { display: grid; gap: 24px; }

.grid-2 {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
}

.grid-3 {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  margin-bottom: 48px;
}

.grid-3-icon {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 48px;
}

@media (max-width: 768px) {
  .grid-2, .grid-3, .grid-3-icon { grid-template-columns: 1fr; gap: 32px; }
}

.card {
  background: white;
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 24px;
  box-shadow: var(--shadow-sm);
  transition: box-shadow 0.2s;
  display: block;
}

.card:hover {
  box-shadow: var(--shadow);
}

.topic-card:hover {
  transform: translateY(-2px);
  border-color: var(--accent);
}

.topic-icon {
  width: 40px;
  height: 40px;
  margin-bottom: 16px;
  color: var(--accent);
}

.topic-icon svg {
  width: 100%;
  height: 100%;
  stroke-width: 1.5;
}

.link-text {
  display: block;
  margin-top: 16px;
  color: var(--accent);
  font-weight: 600;
  font-size: 0.9375rem;
}

.icon-box {
  width: 48px;
  height: 48px;
  background: var(--panel-2);
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--accent);
  margin-bottom: 16px;
}

.icon-box svg {
  width: 24px;
  height: 24px;
  stroke-width: 2;
}

.card h3 {
  font-size: 1.125rem;
  font-weight: 600;
  margin: 0 0 8px;
  color: var(--text);
}

.muted { color: var(--muted); }

.pill-row {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 24px;
}

.pill {
  font-size: 0.875rem;
  padding: 6px 12px;
  border-radius: 999px;
  background: var(--panel-2);
  color: var(--muted);
  font-weight: 500;
}

.callout {
  border-left: 4px solid var(--accent);
  padding: 20px;
  background: rgba(37, 99, 235, 0.05);
  border-radius: 0 8px 8px 0;
}

.callout strong {
  display: block;
  margin-bottom: 4px;
  color: var(--text);
}

.small { font-size: 0.875rem; }

.hr {
  height: 1px;
  background: var(--border);
  margin: 32px 0;
}

.grid-4-step {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
}

.step-card {
  position: relative;
}

.step-num {
  width: 32px;
  height: 32px;
  background: var(--accent);
  color: white;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  margin-bottom: 16px;
}

@media (max-width: 900px) {
  .grid-4-step {
    grid-template-columns: 1fr;
    gap: 32px;
  }
}

footer {
  border-top: 1px solid var(--border);
  background: white;
  padding: 48px 0;
  color: var(--muted);
}

.field {
  width: 100%;
  border-radius: 6px;
  border: 1px solid var(--border);
  background: white;
  color: var(--text);
  padding: 12px;
  font: inherit;
  transition: border-color 0.2s, box-shadow 0.2s;
}

.field:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

.toolbar {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 24px;
}

.toolbar .btn-row { margin-top: 0; }

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