/* ============================================
   YunMail Design System
   Clean, professional, no-nonsense
   ============================================ */

:root {
    /* Color Palette - Neutral with blue accent */
    --color-primary: #2563eb;
    --color-primary-hover: #1d4ed8;
    --color-primary-light: #dbeafe;
    --color-primary-50: #eff6ff;
    
    --color-success: #16a34a;
    --color-success-light: #dcfce7;
    --color-warning: #d97706;
    --color-warning-light: #fef3c7;
    --color-danger: #dc2626;
    --color-danger-light: #fee2e2;
    
    /* Neutrals */
    --color-white: #ffffff;
    --color-gray-25: #fcfcfd;
    --color-gray-50: #f9fafb;
    --color-gray-100: #f3f4f6;
    --color-gray-200: #e5e7eb;
    --color-gray-300: #d1d5db;
    --color-gray-400: #9ca3af;
    --color-gray-500: #6b7280;
    --color-gray-600: #4b5563;
    --color-gray-700: #374151;
    --color-gray-800: #1f2937;
    --color-gray-900: #111827;
    
    /* Surfaces */
    --bg-page: var(--color-gray-50);
    --bg-surface: var(--color-white);
    --bg-surface-raised: var(--color-white);
    --bg-sidebar: var(--color-white);
    --bg-sidebar-hover: var(--color-gray-50);
    --bg-sidebar-active: var(--color-primary-light);
    
    /* Text */
    --text-primary: var(--color-gray-900);
    --text-secondary: var(--color-gray-600);
    --text-tertiary: var(--color-gray-400);
    --text-inverse: var(--color-white);
    --text-link: var(--color-primary);
    
    /* Borders */
    --border-default: var(--color-gray-200);
    --border-light: var(--color-gray-100);
    --border-focus: var(--color-primary);
    
    /* Shadows */
    --shadow-xs: 0 1px 2px rgba(0,0,0,0.05);
    --shadow-sm: 0 1px 3px rgba(0,0,0,0.1), 0 1px 2px rgba(0,0,0,0.06);
    --shadow-md: 0 4px 6px -1px rgba(0,0,0,0.1), 0 2px 4px -2px rgba(0,0,0,0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0,0,0,0.1), 0 4px 6px -4px rgba(0,0,0,0.1);
    --shadow-xl: 0 20px 25px -5px rgba(0,0,0,0.1), 0 8px 10px -6px rgba(0,0,0,0.1);
    
    /* Spacing */
    --space-1: 4px;
    --space-2: 8px;
    --space-3: 12px;
    --space-4: 16px;
    --space-5: 20px;
    --space-6: 24px;
    --space-8: 32px;
    --space-10: 40px;
    --space-12: 48px;
    --space-16: 64px;
    --space-20: 80px;
    --space-24: 96px;
    
    /* Radius */
    --radius-sm: 6px;
    --radius-md: 8px;
    --radius-lg: 12px;
    --radius-xl: 16px;
    --radius-2xl: 20px;
    --radius-full: 9999px;
    
    /* Typography */
    --font-sans: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', 'Helvetica Neue', Helvetica, Arial, sans-serif;
    --font-mono: 'SF Mono', 'Fira Code', 'Fira Mono', 'Roboto Mono', 'Courier New', monospace;
    
    --text-xs: 12px;
    --text-sm: 13px;
    --text-base: 14px;
    --text-md: 15px;
    --text-lg: 16px;
    --text-xl: 18px;
    --text-2xl: 20px;
    --text-3xl: 24px;
    --text-4xl: 30px;
    --text-5xl: 36px;
    --text-6xl: 48px;
    
    --leading-tight: 1.25;
    --leading-normal: 1.5;
    --leading-relaxed: 1.625;
    
    --weight-normal: 400;
    --weight-medium: 500;
    --weight-semibold: 600;
    --weight-bold: 700;
    
    /* Layout */
    --sidebar-width: 220px;
    --header-height: 56px;
    --transition-fast: 150ms ease;
    --transition-normal: 200ms ease;
    --transition-slow: 300ms ease;
}