:root {
    /* ============================================
     * COLOR PALETTE - White, Black, Blueviolet
     * ============================================ */
    
    /* Primary - Black */
    --color-primary: oklch(15% 0 0);
    --color-primary-light: oklch(25% 0 0);
    --color-primary-dark: oklch(8% 0 0);
    
    /* Accent - Blueviolet */
    --color-accent: oklch(55% 0.18 285);
    --color-accent-hover: oklch(48% 0.18 285);
    --color-accent-subtle: oklch(94% 0.03 285);
    
    /* Secondary - Blueviolet Light */
    --color-secondary: oklch(70% 0.12 285);
    --color-secondary-hover: oklch(62% 0.12 285);
    --color-secondary-subtle: oklch(94% 0.02 285);
    
    /* Neutral - White */
    --color-bg: oklch(99% 0 0);
    --color-bg-subtle: oklch(96% 0 0);
    --color-bg-elevated: oklch(100% 0 0);
    --color-surface: oklch(100% 0 0);
    
    /* Text hierarchy */
    --color-text: oklch(15% 0 0);
    --color-text-secondary: oklch(45% 0 0);
    --color-text-tertiary: oklch(65% 0 0);
    --color-text-inverse: oklch(99% 0 0);
    
    /* Border */
    --color-border: oklch(90% 0 0);
    --color-border-strong: oklch(75% 0 0);
    --color-border-focus: oklch(55% 0.18 285);
    
    /* Status colors */
    --color-success: oklch(50% 0.12 155);
    --color-success-bg: oklch(94% 0.02 155);
    --color-warning: oklch(72% 0.14 75);
    --color-warning-bg: oklch(94% 0.02 75);
    --color-danger: oklch(50% 0.18 25);
    --color-danger-hover: oklch(45% 0.18 25);
    --color-danger-bg: oklch(94% 0.03 25);
    --color-info: oklch(55% 0.14 235);
    --color-info-bg: oklch(94% 0.02 235);
    
    /* Sidebar transparency */
    --color-sidebar-overlay: rgba(255, 255, 255, 0.1);
    --color-sidebar-shadow: rgba(0, 0, 0, 0.15);
    --color-sidebar-text: rgba(255, 255, 255, 0.75);
    
    /* ============================================
     * TYPOGRAPHY
     * ============================================ */
    
    --font-sans: 'Cairo', 'Segoe UI', system-ui, -apple-system, sans-serif;
    --font-mono: 'SF Mono', 'Fira Code', 'Consolas', monospace;
    
    --text-xs: clamp(0.75rem, 0.7rem + 0.25vw, 0.8125rem);
    --text-sm: clamp(0.875rem, 0.8rem + 0.375vw, 0.9375rem);
    --text-base: clamp(1rem, 0.9rem + 0.5vw, 1.0625rem);
    --text-lg: clamp(1.125rem, 1rem + 0.625vw, 1.25rem);
    --text-xl: clamp(1.25rem, 1.1rem + 0.75vw, 1.5rem);
    --text-2xl: clamp(1.5rem, 1.25rem + 1.25vw, 2rem);
    --text-3xl: clamp(1.875rem, 1.5rem + 1.875vw, 2.5rem);
    --text-4xl: clamp(2.25rem, 1.75rem + 2.5vw, 3.5rem);
    
    --leading-tight: 1.2;
    --leading-normal: 1.6;
    --leading-relaxed: 1.75;
    
    --tracking-tight: -0.02em;
    --tracking-normal: 0;
    --tracking-wide: 0.03em;
    
    --weight-normal: 400;
    --weight-medium: 500;
    --weight-semibold: 600;
    --weight-bold: 700;
    
    /* ============================================
     * SPACING
     * ============================================ */
    
    --space-1: clamp(0.25rem, 0.2rem + 0.25vw, 0.375rem);
    --space-2: clamp(0.5rem, 0.4rem + 0.5vw, 0.75rem);
    --space-3: clamp(0.75rem, 0.6rem + 0.75vw, 1rem);
    --space-4: clamp(1rem, 0.8rem + 1vw, 1.25rem);
    --space-5: clamp(1.25rem, 1rem + 1.25vw, 1.75rem);
    --space-6: clamp(1.5rem, 1.2rem + 1.5vw, 2rem);
    --space-8: clamp(2rem, 1.5rem + 2.5vw, 3rem);
    --space-10: clamp(2.5rem, 2rem + 2.5vw, 3.5rem);
    --space-12: clamp(3rem, 2.5rem + 2.5vw, 4rem);
    --space-16: clamp(4rem, 3rem + 5vw, 6rem);
    
    /* ============================================
     * BORDERS & RADIUS
     * ============================================ */
    
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 12px;
    --radius-xl: 16px;
    --radius-full: 9999px;
    
    --border-thin: 1px;
    --border-medium: 2px;
    --border-thick: 3px;
    
    /* ============================================
     * SHADOWS
     * ============================================ */
    
    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.08);
    --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 12px 28px rgba(0, 0, 0, 0.12);
    --shadow-xl: 0 24px 48px rgba(0, 0, 0, 0.15);
    --shadow-violet: 0 4px 20px rgba(138, 43, 226, 0.2);
    
    /* ============================================
     * TRANSITIONS & MOTION
     * ============================================ */
    
    --duration-fast: 150ms;
    --duration-normal: 250ms;
    --duration-slow: 400ms;
    
    --ease-out-quart: cubic-bezier(0.25, 1, 0.5, 1);
    --ease-out-quint: cubic-bezier(0.22, 1, 0.36, 1);
    --ease-in-out: cubic-bezier(0.4, 0, 0.2, 1);
    
    --transition: all var(--duration-normal) var(--ease-out-quart);
    
    /* ============================================
     * LAYOUT
     * ============================================ */
    
    --container-max: 1200px;
    --container-narrow: 800px;
    
    --z-base: 0;
    --z-dropdown: 100;
    --z-sticky: 200;
    --z-overlay: 300;
    --z-modal: 400;
    --z-toast: 500;
    --z-tooltip: 1000;
    
    /* Focus ring */
    --focus-ring-offset: 3px;
    --focus-ring-width: 2px;
    
    --dir: ltr;
    --text-align-start: left;
    --text-align-end: right;
    --flex-direction: row;
}

[dir="rtl"] {
    --dir: rtl;
    --text-align-start: right;
    --text-align-end: left;
    --flex-direction: row-reverse;
}

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

html {
    font-size: 16px;
    scroll-behavior: smooth;
    -webkit-text-size-adjust: 100%;
}

@media (prefers-reduced-motion: reduce) {
    html {
        scroll-behavior: auto;
    }
    
    *, *::before, *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}

body {
    font-family: var(--font-sans);
    font-size: var(--text-base);
    line-height: var(--leading-normal);
    color: var(--color-text);
    background-color: var(--color-bg);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

:focus {
    outline: none;
}

:focus-visible {
    outline: var(--focus-ring-width) solid var(--color-accent);
    outline-offset: 2px;
    border-radius: var(--radius-sm);
}

::selection {
    background-color: var(--color-accent);
    color: var(--color-text-inverse);
}

h1, h2, h3, h4, h5, h6 {
    font-weight: var(--weight-bold);
    line-height: var(--leading-tight);
    letter-spacing: var(--tracking-tight);
}

h1 { font-size: var(--text-4xl); }
h2 { font-size: var(--text-3xl); }
h3 { font-size: var(--text-2xl); }
h4 { font-size: var(--text-xl); }
h5 { font-size: var(--text-lg); }
h6 { font-size: var(--text-base); }

p {
    margin-bottom: var(--space-4);
}

a {
    color: var(--color-accent);
    text-decoration: none;
    transition: color var(--duration-fast) var(--ease-out-quart);
}

a:hover {
    color: var(--color-accent-hover);
}

input, textarea, select, button {
    font-family: inherit;
    font-size: inherit;
    line-height: inherit;
}

button {
    cursor: pointer;
    border: none;
    background: none;
}

.container {
    max-width: var(--container-max);
    margin-inline: auto;
    padding-inline: var(--space-4);
    width: 100%;
}

.container-narrow {
    max-width: var(--container-narrow);
}

.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

.text-start { text-align: var(--text-align-start); }
.text-end { text-align: var(--text-align-end); }
.text-center { text-align: center; }

.flex { display: flex; }
.flex-col { flex-direction: column; }
.items-center { align-items: center; }
.justify-center { justify-content: center; }
.justify-between { justify-content: space-between; }
.gap-2 { gap: var(--space-2); }
.gap-4 { gap: var(--space-4); }
.gap-6 { gap: var(--space-6); }

.grid {
    display: grid;
    gap: var(--space-4);
}

.card {
    background: var(--color-surface);
    border: var(--border-thin) solid var(--color-border);
    border-radius: var(--radius-lg);
    padding: var(--space-5);
    transition: var(--transition);
}

.card:hover {
    border-color: var(--color-border-strong);
    box-shadow: var(--shadow-md);
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-2);
    padding: var(--space-3) var(--space-5);
    font-size: var(--text-sm);
    font-weight: var(--weight-semibold);
    line-height: 1;
    border-radius: var(--radius-md);
    transition: var(--transition);
    cursor: pointer;
}

.btn-primary {
    background-color: var(--color-primary);
    color: var(--color-text-inverse);
    border: var(--border-thin) solid var(--color-primary);
}

.btn-primary:hover {
    background-color: var(--color-primary-light);
    border-color: var(--color-primary-light);
}

.btn-secondary {
    background-color: var(--color-surface);
    color: var(--color-text);
    border: var(--border-thin) solid var(--color-border);
}

.btn-secondary:hover {
    background-color: var(--color-bg-subtle);
    border-color: var(--color-border-strong);
}

.btn-accent {
    background-color: var(--color-accent);
    color: var(--color-text-inverse);
    border: var(--border-thin) solid var(--color-accent);
}

.btn-accent:hover {
    background-color: var(--color-accent-hover);
    border-color: var(--color-accent-hover);
}

.btn-secondary-accent {
    background-color: var(--color-secondary-subtle);
    color: var(--color-accent);
    border: var(--border-thin) solid var(--color-secondary);
}

.btn-secondary-accent:hover {
    background-color: var(--color-secondary);
    color: var(--color-text-inverse);
}

.btn-danger {
    background-color: var(--color-danger);
    color: var(--color-text-inverse);
    border: var(--border-thin) solid var(--color-danger);
}

.btn-danger:hover {
    background-color: var(--color-danger-hover);
    border-color: var(--color-danger-hover);
}

.form-input {
    width: 100%;
    padding: var(--space-3) var(--space-4);
    font-size: var(--text-base);
    color: var(--color-text);
    background-color: var(--color-surface);
    border: var(--border-medium) solid var(--color-border);
    border-radius: var(--radius-md);
    transition: var(--transition);
}

.form-input:focus {
    border-color: var(--color-accent);
    box-shadow: 0 0 0 3px var(--color-accent-subtle);
}

.form-input::placeholder {
    color: var(--color-text-tertiary);
}

.badge {
    display: inline-flex;
    align-items: center;
    padding: var(--space-1) var(--space-3);
    font-size: var(--text-xs);
    font-weight: var(--weight-semibold);
    border-radius: var(--radius-full);
}

.badge-success {
    background-color: var(--color-success-bg);
    color: var(--color-success);
}

.badge-warning {
    background-color: var(--color-warning-bg);
    color: var(--color-warning);
}

.badge-danger {
    background-color: var(--color-danger-bg);
    color: var(--color-danger);
}

.badge-info {
    background-color: var(--color-info-bg);
    color: var(--color-info);
}