/* ==========================================================================
   Analog Intuition — Shared Design System (Foundation)
   Goal: Reduce duplication, enable wider/professional layouts, unify branding.
   Usage: <link rel="stylesheet" href="../shared.css"> (adjust path) in new pages.
   Individual tool pages can opt-in gradually without breaking.
   ========================================================================== */

:root {
  /* Brand Colors (refined from existing #003087 / #1a73e8 + gold) */
  --ai-blue-900: #001f5c;
  --ai-blue-800: #003087;
  --ai-blue-700: #0f4c9e;
  --ai-blue-600: #1a73e8;   /* Current dominant button/header blue in most tools */
  --ai-blue-500: #3b8ef0;
  --ai-gold: #d4a017;       /* Consistent accent/hover across site */
  --ai-gold-dark: #b38a12;

  /* Neutrals */
  --ai-gray-900: #1f2937;
  --ai-gray-800: #374151;
  --ai-gray-700: #4b5563;
  --ai-gray-600: #6b7280;
  --ai-gray-500: #9ca3af;
  --ai-gray-200: #e5e7eb;
  --ai-gray-100: #f3f4f6;
  --ai-gray-50:  #f9fafb;

  /* Backgrounds */
  --ai-bg-page: #f4f6f8;
  --ai-bg-card: #ffffff;
  --ai-bg-input: #f9f9f9;

  /* Typography */
  --ai-font-sans: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --ai-font-mono: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;

  /* Spacing scale (tighter than old 20px everywhere) */
  --ai-space-1: 4px;
  --ai-space-2: 8px;
  --ai-space-3: 12px;
  --ai-space-4: 16px;
  --ai-space-5: 20px;
  --ai-space-6: 24px;
  --ai-space-8: 32px;

  /* Radii & Shadows */
  --ai-radius-sm: 4px;
  --ai-radius-md: 6px;
  --ai-radius-lg: 8px;
  --ai-radius-xl: 12px;

  --ai-shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
  --ai-shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
  --ai-shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);

  /* Layout */
  --ai-container-max: 1600px;
  --ai-container-padding: 0 24px;
}

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

body {
  font-family: var(--ai-font-sans);
  background-color: var(--ai-bg-page);
  color: var(--ai-gray-900);
  margin: 0;
  line-height: 1.5;
}

/* Wider, professional container (use on home, tools directory, resources) */
.ai-container {
  max-width: var(--ai-container-max);
  margin: 0 auto;
  padding: var(--ai-container-padding);
}

.ai-section {
  background: var(--ai-bg-card);
  border-radius: var(--ai-radius-lg);
  box-shadow: var(--ai-shadow-md);
  padding: var(--ai-space-6);
  margin-bottom: var(--ai-space-6);
}

/* Header (unified branding) */
.ai-header {
  background: linear-gradient(135deg, var(--ai-blue-800) 0%, var(--ai-blue-700) 100%);
  color: white;
  padding: var(--ai-space-5) var(--ai-space-6);
  border-radius: var(--ai-radius-lg);
  margin-bottom: var(--ai-space-5);
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: var(--ai-space-4);
}

.ai-header h1 {
  margin: 0;
  font-size: 1.5rem;
  font-weight: 600;
  letter-spacing: -0.02em;
  color: white;   /* Explicit so old tool h1 styles don't override it */
}

.ai-header .ai-header-actions {
  display: flex;
  align-items: center;
  gap: var(--ai-space-4);
  font-size: 0.95rem;
}

/* Navigation */
.ai-nav {
  display: flex;
  gap: var(--ai-space-5);
  align-items: center;
}

.ai-nav a {
  color: rgba(255,255,255,0.9);
  text-decoration: none;
  font-weight: 500;
  padding: 4px 0;
  border-bottom: 2px solid transparent;
  transition: all 0.15s ease;
}

.ai-nav a:hover {
  color: white;
  border-bottom-color: var(--ai-gold);
}

.ai-nav a.active {
  color: white;
  border-bottom-color: var(--ai-gold);
}

/* Buttons (unified) */
.ai-button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--ai-space-2);
  background-color: var(--ai-blue-600);
  color: white;
  border: none;
  padding: 10px 18px;
  font-size: 0.95rem;
  font-weight: 500;
  border-radius: var(--ai-radius-md);
  cursor: pointer;
  text-decoration: none;
  transition: background-color 0.15s ease, transform 0.1s ease;
}

.ai-button:hover {
  background-color: var(--ai-blue-700);
}

.ai-button:active {
  transform: translateY(1px);
}

.ai-button.secondary {
  background-color: transparent;
  color: var(--ai-blue-600);
  border: 1px solid var(--ai-blue-600);
}

.ai-button.secondary:hover {
  background-color: var(--ai-blue-600);
  color: white;
}

.ai-button.gold {
  background-color: var(--ai-gold);
  color: #1f2937;
}

.ai-button.gold:hover {
  background-color: var(--ai-gold-dark);
  color: white;
}

.ai-button.small {
  padding: 6px 12px;
  font-size: 0.85rem;
}

/* Form elements (improved density + consistency) */
.ai-param-group {
  margin-bottom: var(--ai-space-4);
}

.ai-param-group label {
  display: block;
  font-weight: 600;
  font-size: 0.9rem;
  color: var(--ai-gray-700);
  margin-bottom: var(--ai-space-1);
}

.ai-input,
.ai-param-group input[type="number"],
.ai-param-group select {
  width: 100%;
  max-width: 220px;
  padding: 7px 10px;
  border: 1px solid var(--ai-gray-200);
  border-radius: var(--ai-radius-sm);
  font-size: 0.95rem;
  background: white;
  transition: border-color 0.15s, box-shadow 0.15s;
}

.ai-input:focus,
.ai-param-group input[type="number"]:focus,
.ai-param-group select:focus {
  outline: none;
  border-color: var(--ai-blue-600);
  box-shadow: 0 0 0 3px rgba(26, 115, 232, 0.15);
}

/* Range sliders (improved thumb) */
.ai-param-group input[type="range"] {
  width: 100%;
  max-width: 220px;
  accent-color: var(--ai-blue-600);
  height: 6px;
  background: var(--ai-gray-200);
  border-radius: 999px;
  margin: 6px 0;
}

.ai-param-group input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 16px;
  height: 16px;
  background: var(--ai-blue-600);
  border-radius: 50%;
  cursor: pointer;
  border: 2px solid white;
  box-shadow: 0 1px 3px rgba(0,0,0,0.2);
}

.ai-param-group input[type="range"]::-moz-range-thumb {
  width: 16px;
  height: 16px;
  background: var(--ai-blue-600);
  border-radius: 50%;
  cursor: pointer;
  border: 2px solid white;
  box-shadow: 0 1px 3px rgba(0,0,0,0.2);
}

/* Cards for tools directory */
.ai-card {
  background: var(--ai-bg-card);
  border: 1px solid var(--ai-gray-200);
  border-radius: var(--ai-radius-lg);
  padding: var(--ai-space-5);
  transition: transform 0.15s ease, box-shadow 0.15s ease, border-color 0.15s;
  display: flex;
  flex-direction: column;
  height: 100%;
}

.ai-card:hover {
  transform: translateY(-2px);
  box-shadow: var(--ai-shadow-lg);
  border-color: var(--ai-blue-600);
}

.ai-card .ai-card-title {
  font-weight: 600;
  font-size: 1.05rem;
  color: var(--ai-blue-800);
  margin: 0 0 var(--ai-space-2) 0;
  text-decoration: none;
}

.ai-card .ai-card-title:hover {
  color: var(--ai-blue-600);
}

.ai-card .ai-card-desc {
  font-size: 0.9rem;
  color: var(--ai-gray-600);
  line-height: 1.4;
  flex: 1;
  margin-bottom: var(--ai-space-3);
}

.ai-card .ai-card-meta {
  font-size: 0.75rem;
  color: var(--ai-gray-500);
  display: flex;
  gap: var(--ai-space-2);
  align-items: center;
}

/* Utility classes */
.ai-text-muted { color: var(--ai-gray-600); }
.ai-text-small { font-size: 0.85rem; }
.ai-mt-4 { margin-top: var(--ai-space-4); }
.ai-mb-4 { margin-bottom: var(--ai-space-4); }

/* Responsive helpers */
@media (max-width: 768px) {
  .ai-header {
    flex-direction: column;
    align-items: flex-start;
  }
  .ai-nav {
    width: 100%;
    justify-content: flex-start;
    flex-wrap: wrap;
  }
}

/* Future: Wide tool layout skeleton (documented, not enforced yet)
   .ai-tool-layout { display: grid; grid-template-columns: 320px 1fr; gap: 24px; }
   .ai-tool-controls { ... }
   .ai-tool-viz { ... }  /* large chart area */
*/