/* css/1-base.css */
/* 
 * This file defines the complete design token system using CSS variables.
 * All colors, spacing, typography, shadows, and other design values are
 * centralized here and referenced throughout the application via var() syntax.
 * This enables consistent styling and easy theming updates.
 *
 * TYPOGRAPHY STYLE GUIDE:
 * - UI labels, headers, tabs, and buttons use LOWERCASE text for a modern aesthetic
 * - Only uppercase badges (PRO, OFFICIAL) and brand names use text-transform: uppercase
 * - Use --letter-spacing-ui (0.02em) for lowercase UI text
 * - Use --letter-spacing-badge (0.5px) for uppercase badge text
 * - Prefer font-weight: 600 (semibold) for headers; 700 reserved for emphasis/badges
 */

/* ========================================================================== */
/* DESIGN TOKENS - Centralized design system variables */
/* ========================================================================== */

:root {
    /* ─────────────────────────────────────────────────────────────────── */
    /* Colors - Brand & Primary */
    /* ─────────────────────────────────────────────────────────────────── */
    --color-primary: #667eea;
    --color-primary-dark: #764ba2;
    --color-primary-gradient-start: #667eea;
    --color-primary-gradient-end: #764ba2;
    
    /* Colors - Premium / Accent Gradient */
    --color-premium-gradient-start: #f093fb;
    --color-premium-gradient-end: #f5576c;
    
    /* Colors - Text */
    --color-text-primary: #333;
    --color-text-secondary: #555;
    --color-text-muted: #888;
    --color-text-light: #999;
    --color-text-lighter: #aaa;
    --color-text-on-brand: white;
    
    /* Colors - Backgrounds */
    --color-bg-primary: white;
    --color-bg-secondary: #f9f9f9;
    --color-bg-tertiary: #f5f5f5;
    --color-bg-overlay: rgba(0, 0, 0, 0.5);
    
    /* Colors - Borders */
    --color-border-dark: #bbb;
    --color-border-medium: #d0d0d0;
    --color-border-light: #eee;
    --color-border-lighter: #ccc;
    
    /* Colors - Status & Semantic */
    --color-danger: #f44336;
    --color-success: #4CAF50;
    --color-warning: #ff9800;
    --color-info: #2196F3;
    
    /* Colors - UI States */
    --color-disabled: #999;
    --color-disabled-bg: #f0f0f0;
    
    /* ─────────────────────────────────────────────────────────────────── */
    /* Typography */
    /* ─────────────────────────────────────────────────────────────────── */
    --font-family-base: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    
    --font-size-xs: 0.75rem;
    --font-size-sm: 0.9rem;
    --font-size-base: 1rem;
    --font-size-lg: 1.3rem;
    --font-size-xl: 1.5rem;
    
    --font-weight-normal: 400;
    --font-weight-medium: 500;
    --font-weight-semibold: 600;
    --font-weight-bold: 700;
    
    --line-height-tight: 1.2;
    --line-height-normal: 1.5;
    --line-height-relaxed: 1.6;
    
    /* Letter spacing - UI uses lowercase, minimal spacing */
    --letter-spacing-normal: 0;
    --letter-spacing-ui: 0.02em;
    --letter-spacing-badge: 0.5px; /* For uppercase badges only */
    
    /* ─────────────────────────────────────────────────────────────────── */
    /* Spacing Scale - Based on 4px and 8px units */
    /* ─────────────────────────────────────────────────────────────────── */
    --spacing-xs: 4px;
    --spacing-sm: 8px;
    --spacing-md: 12px;
    --spacing-lg: 16px;
    --spacing-xl: 20px;
    --spacing-2xl: 24px;
    
    /* Aliases for common spacing patterns */
    --spacing-inline-xs: var(--spacing-xs);
    --spacing-inline-sm: var(--spacing-sm);
    --spacing-inline-md: var(--spacing-md);
    --spacing-inline-lg: var(--spacing-lg);
    
    --spacing-block-xs: var(--spacing-xs);
    --spacing-block-sm: var(--spacing-sm);
    --spacing-block-md: var(--spacing-md);
    --spacing-block-lg: var(--spacing-lg);
    
    /* ─────────────────────────────────────────────────────────────────── */
    /* Border Radius */
    /* ─────────────────────────────────────────────────────────────────── */
    --radius-xs: 4px;
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 20px;
    --radius-full: 50%;
    
    /* ─────────────────────────────────────────────────────────────────── */
    /* Shadows */
    /* ─────────────────────────────────────────────────────────────────── */
    --shadow-xs: 0 1px 3px rgba(0, 0, 0, 0.1);
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.1);
    --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 5px 15px rgba(0, 0, 0, 0.2);
    --shadow-xl: 0 20px 60px rgba(0, 0, 0, 0.3);
    
    /* Brand-colored shadows */
    --shadow-primary-sm: 0 2px 8px rgba(102, 126, 234, 0.15);
    --shadow-primary-md: 0 5px 15px rgba(102, 126, 234, 0.3);
    --shadow-primary-lg: 0 5px 15px rgba(102, 126, 234, 0.4);
    
    /* ─────────────────────────────────────────────────────────────────── */
    /* Transitions & Animations */
    /* ─────────────────────────────────────────────────────────────────── */
    --transition-fast: 0.2s ease;
    --transition-base: 0.3s ease;
    --transition-slow: 0.5s ease;
    
    /* ─────────────────────────────────────────────────────────────────── */
    /* Z-Index Scale */
    /* ─────────────────────────────────────────────────────────────────── */
    --z-base: 1;
    --z-dropdown: 5;
    --z-overlay: 10;
    --z-modal: 1000;
    --z-modal-overlay: 1010;
    --z-modal-content: 1020;
    
    /* ─────────────────────────────────────────────────────────────────── */
    /* Gradients - Predefined */
    /* ─────────────────────────────────────────────────────────────────── */
    --gradient-primary: linear-gradient(135deg, var(--color-primary-gradient-start) 0%, var(--color-primary-gradient-end) 100%);
    --gradient-premium: linear-gradient(135deg, var(--color-premium-gradient-start) 0%, var(--color-premium-gradient-end) 100%);
    --gradient-official-friend: linear-gradient(135deg, #f0f7ff 0%, #f5f0ff 100%);
}

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

body {
    font-family: var(--font-family-base);
    background: var(--color-bg-tertiary);
    min-height: 100vh;
}