/**
 * TechGuide Design System - CSS Variables
 * Configurable design tokens for colors, typography, spacing, and elevation.
 */
:root {
  /* Brand Colors */
  --primary-color: #1d4ed8;       /* Deep professional blue */
  --primary-hover: #1e40af;
  --primary-light: #eff6ff;
  --secondary-color: #0d9488;     /* Teal accent */
  --secondary-hover: #0f766e;
  --secondary-light: #f0fdfa;

  /* Neutrals & Text */
  --text-color: #0f172a;          /* Slate 900 - High contrast, legible */
  --text-secondary: #475569;    /* Slate 600 */
  --muted-text: #64748b;        /* Slate 500 */
  --background-color: #f8fafc;  /* Clean, warm-cool off-white */
  --surface-color: #ffffff;     /* Pure white for cards & containers */
  --surface-secondary: #f1f5f9; /* Slate 100 */
  --border-color: #e2e8f0;      /* Slate 200 */
  --border-focus: #93c5fd;

  /* Feedback & Alerts */
  --success-bg: #ecfdf5;
  --success-border: #a7f3d0;
  --success-text: #065f46;
  --warning-bg: #fffbeb;
  --warning-border: #fde68a;
  --warning-text: #92400e;
  --tip-bg: #eff6ff;
  --tip-border: #bfdbfe;
  --tip-text: #1e40af;
  --danger-bg: #fef2f2;
  --danger-border: #fecaca;
  --danger-text: #991b1b;

  /* Layout & Sizing */
  --container-width: 1200px;
  --article-width: 780px;
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 14px;
  --radius-pill: 9999px;

  /* Shadows */
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.07), 0 2px 4px -2px rgba(0, 0, 0, 0.05);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.08), 0 4px 6px -4px rgba(0, 0, 0, 0.04);

  /* Typography */
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --font-serif: "Charter", "Bitstream Charter", "Sitka Text", Cambria, Georgia, serif;
  --font-mono: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;
  
  --transition-fast: 0.15s ease;
  --transition-normal: 0.25s ease;
}

/* Dark Mode (Class-based & prefers-color-scheme friendly) */
[data-theme="dark"] {
  --primary-color: #3b82f6;
  --primary-hover: #60a5fa;
  --primary-light: #1e293b;
  --secondary-color: #14b8a6;
  --secondary-hover: #2dd4bf;
  --secondary-light: #134e4a;

  --text-color: #f1f5f9;
  --text-secondary: #cbd5e1;
  --muted-text: #94a3b8;
  --background-color: #0b0f19;
  --surface-color: #131b2e;
  --surface-secondary: #1e293b;
  --border-color: #26334d;
  --border-focus: #60a5fa;

  --success-bg: #064e3b;
  --success-border: #047857;
  --success-text: #a7f3d0;
  --warning-bg: #451a03;
  --warning-border: #b45309;
  --warning-text: #fde68a;
  --tip-bg: #1e3a8a;
  --tip-border: #2563eb;
  --tip-text: #bfdbfe;
  --danger-bg: #450a0a;
  --danger-border: #b91c1c;
  --danger-text: #fecaca;

  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.4);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.5);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.6);
}