:root {
  /* ===== Brand Colors ===== */
  --color-primary: #074f87;
  --color-primary-dark: #053a63;
  --color-primary-light: #0a6bb8;
  --color-primary-subtle: #e8f0fa;

  --color-accent: #0d6efd;
  --color-accent-dark: #0a58ca;

  /* ===== Neutrals ===== */
  --color-bg: #ffffff;
  --color-bg-alt: #f8f9fb;
  --color-bg-sidebar: #f4f6f9;
  --color-text: #1e293b;
  --color-text-muted: #64748b;
  --color-text-inverse: #ffffff;
  --color-border: #e2e8f0;
  --color-border-light: #f1f5f9;

  /* ===== Semantic ===== */
  --color-success: #16a34a;
  --color-success-bg: #dcfce7;
  --color-warning: #d97706;
  --color-warning-bg: #fef3c7;
  --color-danger: #dc2626;
  --color-danger-bg: #fee2e2;
  --color-info: #0284c7;
  --color-info-bg: #e0f2fe;

  /* ===== Header ===== */
  --header-height: 64px;
  --header-bg: #ffffff;
  --header-border: var(--color-border);
  --header-shadow: 0 1px 3px rgba(0, 0, 0, 0.06);

  /* ===== Sidebar ===== */
  --sidebar-width: 260px;
  --sidebar-bg: var(--color-bg-sidebar);
  --sidebar-link-color: var(--color-text);
  --sidebar-link-hover-bg: #e2e8f0;
  --sidebar-link-active-bg: var(--color-primary-subtle);
  --sidebar-link-active-color: var(--color-primary);
  --sidebar-section-color: var(--color-text-muted);
  --sidebar-font-size: 0.875rem;

  /* ===== Fonts ===== */
  --font-family: 'Segoe UI', system-ui, -apple-system, BlinkMacSystemFont, sans-serif;
  --font-family-mono: 'Cascadia Code', 'Fira Code', 'Consolas', monospace;
  --font-size-base: 0.9375rem;
  --font-size-sm: 0.8125rem;
  --font-size-lg: 1.0625rem;
  --font-size-xl: 1.25rem;
  --font-size-2xl: 1.5rem;
  --line-height: 1.6;

  /* ===== Spacing ===== */
  --content-padding-x: 2rem;
  --content-padding-y: 1.5rem;
  --sidebar-padding-x: 1rem;
  --sidebar-padding-y: 1.25rem;

  /* ===== Borders & Radius ===== */
  --border-radius: 0.375rem;
  --border-radius-lg: 0.5rem;
  --border-radius-xl: 0.75rem;

  /* ===== Shadows ===== */
  --shadow-xs: 0 1px 2px rgba(0, 0, 0, 0.04);
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.06);
  --shadow: 0 4px 6px rgba(0, 0, 0, 0.05), 0 1px 3px rgba(0, 0, 0, 0.06);
  --shadow-md: 0 10px 15px rgba(0, 0, 0, 0.06), 0 4px 6px rgba(0, 0, 0, 0.04);
  --shadow-lg: 0 20px 25px rgba(0, 0, 0, 0.08), 0 10px 10px rgba(0, 0, 0, 0.04);

  /* ===== Transitions ===== */
  --transition-fast: 150ms ease;
  --transition: 200ms ease;
  --transition-slow: 300ms ease;
}