/* CSS custom properties — theme foundation */
:root {
  /* Core palette */
  --color-bg-primary:    #0d1117;
  --color-bg-secondary:  #161b22;
  --color-bg-tertiary:   #1c2128;
  --color-border:        #30363d;
  --color-border-accent: #388bfd;

  /* Text */
  --color-text-primary:  #e6edf3;
  --color-text-secondary:#8b949e;
  --color-text-muted:    #484f58;

  /* Accent */
  --color-accent:        #388bfd;
  --color-accent-hover:  #58a6ff;

  /* Status badge colors */
  --color-status-open:      #da3633;
  --color-status-progress:  #e3b341;
  --color-status-resolved:  #3fb950;
  --color-status-closed:    #8b949e;
  --color-status-critical:  #f78166;

  /* Typography */
  --font-sans: 'Inter', system-ui, sans-serif;
  --font-mono: 'Fira Code', 'JetBrains Mono', monospace;

  /* Spacing */
  --space-xs:  4px;
  --space-sm:  8px;
  --space-md:  16px;
  --space-lg:  24px;
  --space-xl:  48px;

  /* Borders */
  --radius-sm: 4px;
  --radius-md: 6px;
  --radius-lg: 12px;

  /* Transitions */
  --transition-fast: 150ms ease;
  --transition-base: 250ms ease;
}

/* Light mode overrides */
[data-theme="light"] {
  --color-bg-primary:    #ffffff;
  --color-bg-secondary:  #f6f8fa;
  --color-bg-tertiary:   #eaeef2;
  --color-border:        #d0d7de;
  --color-border-accent: #0969da;
  --color-text-primary:  #1f2328;
  --color-text-secondary:#636c76;
  --color-text-muted:    #b1bac4;
  --color-accent:        #0969da;
  --color-accent-hover:  #0550ae;
}

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

body {
  background-color: var(--color-bg-primary);
  color: var(--color-text-primary);
  font-family: var(--font-sans);
  line-height: 1.6;
  transition: background-color 0.3s, color 0.3s;
}

nav {
  display: flex;
  align-items: center;
  gap: var(--space-md);
  padding: var(--space-md) var(--space-xl);
  background: var(--color-bg-secondary);
  border-bottom: 1px solid var(--color-border);
  position: sticky;
  top: 0;
  z-index: 100;
}

.logo {
  font-family: var(--font-mono);
  font-size: 14px;
  color: var(--color-accent);
  font-weight: 500;
}

.logo::before {
  content: '[QA] ';
  color: var(--color-text-muted);
}

nav ul {
  display: flex;
  list-style: none;
  gap: var(--space-xs);
  margin-left: auto;
}

nav a {
  font-size: 13px;
  color: var(--color-text-secondary);
  text-decoration: none;
  padding: var(--space-xs) var(--space-sm);
  border-radius: var(--radius-sm);
  transition: background var(--transition-fast), color var(--transition-fast);
}

nav a:hover {
  background: var(--color-bg-tertiary);
  color: var(--color-text-primary);
}

.reveal {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.5s ease, transform 0.5s ease;
}

.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}