/* Verifiable Proof Systems — Public site */
/* Screen-reader-first, keyboard-first, minimal design */

:root {
  --bg: #ffffff;
  --text: #1a1a2e;
  --accent: #3b49df;
  --accent-light: #e8ebfb;
  --border: #d0d5dd;
  --muted: #667085;
  --font: system-ui, -apple-system, sans-serif;
  --max-width: 720px;
}

* { box-sizing: border-box; }

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


body {
  margin: 0;
  font-family: var(--font);
  color: var(--text);
  background: var(--bg);
  line-height: 1.6;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* Skip link */
.skip-link {
  position: absolute;
  top: -100%;
  left: 8px;
  background: var(--accent);
  color: #fff;
  padding: 8px 16px;
  z-index: 1000;
  border-radius: 4px;
}
.skip-link:focus {
  top: 8px;
}

/* Header / Nav */
header {
  background: var(--bg);
  border-bottom: 1px solid var(--border);
  padding: 12px 24px;
}

nav {
  display: flex;
  align-items: center;
  gap: 24px;
  max-width: var(--max-width);
  margin: 0 auto;
}

.site-title {
  font-weight: 600;
  text-decoration: none;
  color: var(--text);
  white-space: nowrap;
}

nav ul {
  list-style: none;
  padding: 0;
  margin: 0 0 0 auto;
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
}

nav a {
  color: var(--text);
  text-decoration: none;
  font-size: 0.9em;
  padding: 4px 0;
}

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

nav a[aria-current="page"] {
  color: var(--accent);
  border-bottom: 2px solid var(--accent);
}



.nav-toggle {
  display: none;
  background: none;
  border: 1px solid var(--border);
  padding: 6px 12px;
  border-radius: 4px;
  cursor: pointer;
  margin-left: auto;
}

/* Main */
main {
  flex: 1;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 48px 24px;
  width: 100%;
}

main h1 {
  font-size: 2.4em;
  line-height: 1.2;
  margin: 0 0 24px 0;
}

main h2 {
  font-size: 1.5em;
  margin: 40px 0 12px 0;
}

main h3 {
  font-size: 1.2em;
  margin: 28px 0 8px 0;
}

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

main ul, main ol {
  padding-left: 20px;
}

main li {
  margin-bottom: 8px;
}

/* Blockquotes */
blockquote {
  border-left: 3px solid var(--accent);
  margin: 24px 0;
  padding: 8px 16px;
  background: var(--accent-light);
  font-style: italic;
}

blockquote p {
  margin: 0;
}

/* Code blocks */
pre {
  background: #f4f5f7;
  border: 1px solid var(--border);
  border-radius: 4px;
  padding: 16px;
  overflow-x: auto;
  font-size: 0.85em;
  line-height: 1.4;
}

code {
  background: #f4f5f7;
  padding: 2px 4px;
  border-radius: 3px;
  font-size: 0.85em;
}

pre code {
  background: none;
  padding: 0;
}

/* Callout boxes */
.callout {
  background: var(--accent-light);
  border-left: 4px solid var(--accent);
  padding: 16px 20px;
  margin: 24px 0;
  border-radius: 0 4px 4px 0;
}

.callout-warning {
  background: #fff3cd;
  border-left-color: #ffc107;
}

.callout-boundary {
  background: #f8f9fa;
  border-left-color: #dc3545;
  border: 1px solid #e9ecef;
  padding: 16px 20px;
  margin: 24px 0;
  border-radius: 4px;
}

/* Buttons / CTAs */
.cta {
  display: inline-block;
  background: var(--accent);
  color: #fff;
  padding: 12px 24px;
  border-radius: 6px;
  text-decoration: none;
  font-weight: 600;
  margin: 8px 0;
}

.cta:hover {
  background: #2d39b3;
}

.cta-secondary {
  background: transparent;
  color: var(--accent);
  border: 1px solid var(--accent);
}

.cta-secondary:hover {
  background: var(--accent-light);
}

/* Footer */
footer {
  border-top: 1px solid var(--border);
  padding: 24px;
  text-align: center;
  font-size: 0.85em;
  color: var(--muted);
}

footer nav ul {
  list-style: none;
  padding: 0;
  margin: 0 0 12px 0;
  display: flex;
  justify-content: center;
  gap: 16px;
  flex-wrap: wrap;
}

footer nav a {
  color: var(--muted);
  text-decoration: none;
}

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

.footer-boundary {
  margin: 8px 0;
  font-style: italic;
}

.footer-copy {
  margin: 4px 0 0 0;
}

/* Tables */
table {
  width: 100%;
  border-collapse: collapse;
  margin: 24px 0;
  font-size: 0.9em;
}

th, td {
  text-align: left;
  padding: 8px 12px;
  border-bottom: 1px solid var(--border);
  vertical-align: top;
}

th {
  font-weight: 600;
  background: var(--accent-light);
}

/* Post cards (blog) */
.post-card {
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 20px;
  margin: 16px 0;
}

.post-card h2 {
  margin-top: 0;
}

.post-card time {
  color: var(--muted);
  font-size: 0.85em;
}

/* Responsive */
@media (max-width: 700px) {
  main { padding: 24px 16px; }
  main h1 { font-size: 1.8em; }

  nav {
    flex-wrap: wrap;
  }

  .nav-toggle {
    display: block;
  }

  nav ul {
    display: none;
    width: 100%;
    flex-direction: column;
    gap: 4px;
    padding: 8px 0;
  }

  nav ul.open {
    display: flex;
  }
}

/* Reduced motion */
@media (prefers-reduced-motion: reduce) {
  * { transition: none !important; animation: none !important; }
}