/* assets/css/design-system.css */
:root {
    /* Base Typography */
    --kd-font-sans: 'Inter', system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    
    /* Branding Colors (Default Theme) */
    --kd-primary: #2563eb;
    --kd-primary-hover: #1d4ed8;
    --kd-secondary: #475569;
    --kd-secondary-hover: #334155;
    --kd-accent: #3b82f6;
    
    /* State Colors */
    --kd-success: #10b981;
    --kd-success-bg: #d1fae5;
    --kd-warning: #f59e0b;
    --kd-warning-bg: #fef3c7;
    --kd-danger: #ef4444;
    --kd-danger-bg: #fee2e2;
    --kd-info: #3b82f6;
    --kd-info-bg: #dbeafe;

    /* Base Colors (Light Mode Default) */
    --kd-bg-canvas: #f8fafc;
    --kd-bg-surface: #ffffff;
    --kd-bg-sidebar: #ffffff;
    --kd-text-primary: #0f172a;
    --kd-text-secondary: #475569;
    --kd-text-muted: #94a3b8;
    --kd-border-color: #e2e8f0;
    
    /* Radii & Shadows */
    --kd-radius-sm: 0.25rem;
    --kd-radius: 0.5rem;
    --kd-radius-md: 0.75rem;
    --kd-radius-lg: 1rem;
    --kd-radius-full: 9999px;
    
    --kd-shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --kd-shadow: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
    --kd-shadow-md: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
    --kd-shadow-lg: 0 20px 25px -5px rgb(0 0 0 / 0.1), 0 8px 10px -6px rgb(0 0 0 / 0.1);

    /* Spacing System */
    --kd-spacing-1: 0.25rem;
    --kd-spacing-2: 0.5rem;
    --kd-spacing-3: 0.75rem;
    --kd-spacing-4: 1rem;
    --kd-spacing-5: 1.25rem;
    --kd-spacing-6: 1.5rem;
    --kd-spacing-8: 2rem;
    --kd-spacing-10: 2.5rem;
    --kd-spacing-12: 3rem;

    /* Animations */
    --kd-anim-fast: 150ms;
    --kd-anim-normal: 200ms;
    --kd-anim-slow: 250ms;
    
    /* Layout */
    --kd-sidebar-width: 260px;
    --kd-sidebar-collapsed: 80px;
    --kd-header-height: 64px;
}

/* Dark Mode Theme overrides */
html[data-theme="dark"] {
    --kd-bg-canvas: #0f172a;
    --kd-bg-surface: #1e293b;
    --kd-bg-sidebar: #1e293b;
    --kd-text-primary: #f8fafc;
    --kd-text-secondary: #cbd5e1;
    --kd-border-color: #334155;
    --kd-shadow: 0 4px 6px -1px rgb(0 0 0 / 0.3);
}

/* Base Reset & Core Styles */
*, *::before, *::after {
    box-sizing: border-box;
}

body {
    margin: 0;
    font-family: var(--kd-font-sans);
    background-color: var(--kd-bg-canvas);
    color: var(--kd-text-primary);
    line-height: 1.5;
    -webkit-font-smoothing: antialiased;
}

h1, h2, h3, h4, h5, h6 {
    margin: 0 0 var(--kd-spacing-4) 0;
    font-weight: 600;
    color: var(--kd-text-primary);
    line-height: 1.2;
}

h1 { font-size: 32px; font-weight: 700; }
h2 { font-size: 24px; font-weight: 600; }
h3 { font-size: 20px; font-weight: 600; }
h4 { font-size: 18px; font-weight: 500; }

a {
    color: var(--kd-primary);
    text-decoration: none;
    transition: color var(--kd-anim-normal) ease;
}

a:hover {
    color: var(--kd-primary-hover);
}