/**
 * Design System
 * Typography, Colors, Spacing, and Dark Mode Support
 */

/* ============================================================================
   TYPOGRAPHY SYSTEM
   ============================================================================ */

/* Import IBM Plex Sans (Latin) */
@import url('https://fonts.googleapis.com/css2?family=IBM+Plex+Sans:ital,wght@0,300;0,400;0,500;0,600;0,700;1,300;1,400&display=swap');

/* Import IBM Plex Sans Arabic (RTL) */
@import url('https://fonts.googleapis.com/css2?family=IBM+Plex+Sans+Arabic:wght@300;400;500;600;700&display=swap');

:root {
    /* Font Families */
    --font-primary: 'IBM Plex Sans', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    --font-arabic: 'IBM Plex Sans Arabic', 'IBM Plex Sans', sans-serif;
    --font-mono: 'IBM Plex Mono', 'Courier New', monospace;

    /* Font Sizes - Responsive Scale using clamp() */
    --text-xs: clamp(0.75rem, 0.7rem + 0.25vw, 0.875rem);      /* 12px - 14px */
    --text-sm: clamp(0.875rem, 0.8rem + 0.35vw, 1rem);         /* 14px - 16px */
    --text-base: clamp(1rem, 0.95rem + 0.25vw, 1.125rem);      /* 16px - 18px */
    --text-lg: clamp(1.125rem, 1.05rem + 0.35vw, 1.375rem);    /* 18px - 22px */
    --text-xl: clamp(1.25rem, 1.15rem + 0.5vw, 1.75rem);       /* 20px - 28px */
    --text-2xl: clamp(1.5rem, 1.3rem + 1vw, 2.25rem);          /* 24px - 36px */
    --text-3xl: clamp(1.875rem, 1.5rem + 1.5vw, 3rem);         /* 30px - 48px */

    /* Font Weights */
    --weight-light: 300;
    --weight-normal: 400;
    --weight-medium: 500;
    --weight-semibold: 600;
    --weight-bold: 700;

    /* Line Heights */
    --leading-tight: 1.25;
    --leading-normal: 1.5;
    --leading-relaxed: 1.75;

    /* Letter Spacing */
    --tracking-tight: -0.01em;
    --tracking-normal: 0;
    --tracking-wide: 0.025em;
}

/* ============================================================================
   COLOR SYSTEM - LIGHT MODE
   ============================================================================ */

:root {
    /* Primary Colors */
    --color-primary: #0F62FE;
    --color-primary-hover: #0353E9;
    --color-primary-active: #002D9C;
    --color-primary-light: #D0E2FF;
    --color-primary-dark: #001D6C;

    /* Secondary Colors */
    --color-secondary: #8A3FFC;
    --color-secondary-hover: #7A2FF7;
    --color-secondary-active: #6929C4;

    /* Status Colors */
    --color-success: #24A148;
    --color-success-light: #E8F5E9;
    --color-warning: #F1C21B;
    --color-warning-light: #FFF8E1;
    --color-error: #DA1E28;
    --color-error-light: #FFEBEE;
    --color-info: #4589FF;
    --color-info-light: #E3F2FD;

    /* Backgrounds */
    --bg-primary: #FFFFFF;
    --bg-secondary: #F4F4F4;
    --bg-tertiary: #E0E0E0;
    --bg-hover: #E5E5E5;
    --bg-overlay: rgba(22, 22, 22, 0.5);
    --bg-card: #FFFFFF;

    /* Text Colors */
    --text-primary: #161616;
    --text-secondary: #525252;
    --text-tertiary: #8D8D8D;
    --text-inverse: #FFFFFF;
    --text-placeholder: #A8A8A8;
    --text-disabled: #C6C6C6;

    /* Borders */
    --border-color: #E0E0E0;
    --border-strong: #8D8D8D;
    --border-subtle: #F4F4F4;
    --border-interactive: #0F62FE;

    /* Shadows */
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
    --shadow-2xl: 0 25px 50px -12px rgba(0, 0, 0, 0.25);
}

/* ============================================================================
   COLOR SYSTEM - DARK MODE (Auto-detect)
   ============================================================================ */

@media (prefers-color-scheme: dark) {
    :root {
        /* Primary Colors */
        --color-primary: #4589FF;
        --color-primary-hover: #5F9EFF;
        --color-primary-active: #78A9FF;
        --color-primary-light: #001D6C;
        --color-primary-dark: #D0E2FF;

        /* Secondary Colors */
        --color-secondary: #A56EFF;
        --color-secondary-hover: #B785FF;
        --color-secondary-active: #C89BFF;

        /* Status Colors */
        --color-success: #42BE65;
        --color-success-light: #071908;
        --color-warning: #F1C21B;
        --color-warning-light: #1C1A00;
        --color-error: #FA4D56;
        --color-error-light: #2D0709;
        --color-info: #4589FF;
        --color-info-light: #001D6C;

        /* Backgrounds */
        --bg-primary: #161616;
        --bg-secondary: #262626;
        --bg-tertiary: #393939;
        --bg-hover: #4C4C4C;
        --bg-overlay: rgba(255, 255, 255, 0.1);
        --bg-card: #262626;

        /* Text Colors */
        --text-primary: #F4F4F4;
        --text-secondary: #C6C6C6;
        --text-tertiary: #8D8D8D;
        --text-inverse: #161616;
        --text-placeholder: #6F6F6F;
        --text-disabled: #525252;

        /* Borders */
        --border-color: #393939;
        --border-strong: #6F6F6F;
        --border-subtle: #262626;
        --border-interactive: #4589FF;

        /* Shadows */
        --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.3);
        --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.3), 0 2px 4px -1px rgba(0, 0, 0, 0.2);
        --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.3), 0 4px 6px -2px rgba(0, 0, 0, 0.2);
        --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.4), 0 10px 10px -5px rgba(0, 0, 0, 0.3);
        --shadow-2xl: 0 25px 50px -12px rgba(0, 0, 0, 0.5);
    }
}

/* Manual Dark Mode Toggle */
body.dark-mode {
    /* Primary Colors */
    --color-primary: #4589FF;
    --color-primary-hover: #5F9EFF;
    --color-primary-active: #78A9FF;
    --color-primary-light: #001D6C;
    --color-primary-dark: #D0E2FF;

    /* Secondary Colors */
    --color-secondary: #A56EFF;
    --color-secondary-hover: #B785FF;
    --color-secondary-active: #C89BFF;

    /* Status Colors */
    --color-success: #42BE65;
    --color-success-light: #071908;
    --color-warning: #F1C21B;
    --color-warning-light: #1C1A00;
    --color-error: #FA4D56;
    --color-error-light: #2D0709;
    --color-info: #4589FF;
    --color-info-light: #001D6C;

    /* Backgrounds */
    --bg-primary: #161616;
    --bg-secondary: #262626;
    --bg-tertiary: #393939;
    --bg-hover: #4C4C4C;
    --bg-overlay: rgba(255, 255, 255, 0.1);
    --bg-card: #262626;

    /* Text Colors */
    --text-primary: #F4F4F4;
    --text-secondary: #C6C6C6;
    --text-tertiary: #8D8D8D;
    --text-inverse: #161616;
    --text-placeholder: #6F6F6F;
    --text-disabled: #525252;

    /* Borders */
    --border-color: #393939;
    --border-strong: #6F6F6F;
    --border-subtle: #262626;
    --border-interactive: #4589FF;

    /* Shadows */
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.3), 0 2px 4px -1px rgba(0, 0, 0, 0.2);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.3), 0 4px 6px -2px rgba(0, 0, 0, 0.2);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.4), 0 10px 10px -5px rgba(0, 0, 0, 0.3);
    --shadow-2xl: 0 25px 50px -12px rgba(0, 0, 0, 0.5);
}

/* ============================================================================
   SPACING SYSTEM
   ============================================================================ */

:root {
    /* Spacing Scale (8px base) */
    --space-xs: 0.25rem;    /* 4px */
    --space-sm: 0.5rem;     /* 8px */
    --space-md: 1rem;       /* 16px */
    --space-lg: 1.5rem;     /* 24px */
    --space-xl: 2rem;       /* 32px */
    --space-2xl: 3rem;      /* 48px */
    --space-3xl: 4rem;      /* 64px */
    --space-4xl: 6rem;      /* 96px */

    /* Container Widths */
    --container-sm: 640px;
    --container-md: 768px;
    --container-lg: 1024px;
    --container-xl: 1280px;
    --container-2xl: 1536px;

    /* Border Radius */
    --radius-none: 0;
    --radius-sm: 0.25rem;   /* 4px */
    --radius-md: 0.5rem;    /* 8px */
    --radius-lg: 0.75rem;   /* 12px */
    --radius-xl: 1rem;      /* 16px */
    --radius-2xl: 1.5rem;   /* 24px */
    --radius-full: 9999px;

    /* Transitions */
    --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-base: 250ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: 350ms cubic-bezier(0.4, 0, 0.2, 1);

    /* Z-index Scale */
    --z-dropdown: 1000;
    --z-sticky: 1020;
    --z-fixed: 1030;
    --z-modal-backdrop: 1040;
    --z-modal: 1050;
    --z-popover: 1060;
    --z-tooltip: 1070;
}

/* ============================================================================
   BASE STYLES
   ============================================================================ */

body {
    font-family: var(--font-primary);
    font-size: var(--text-base);
    line-height: var(--leading-normal);
    font-weight: var(--weight-normal);
    color: var(--text-primary);
    background-color: var(--bg-primary);
    transition: background-color var(--transition-base), color var(--transition-base);
}

/* RTL Font Family Override */
body.rtl {
    font-family: var(--font-arabic);
}

/* Headings */
h1, h2, h3, h4, h5, h6 {
    font-weight: var(--weight-semibold);
    line-height: var(--leading-tight);
    margin: 0 0 var(--space-md) 0;
    color: var(--text-primary);
}

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

/* Paragraphs */
p {
    margin: 0 0 var(--space-md) 0;
    color: var(--text-secondary);
}

/* Links */
a {
    color: var(--color-primary);
    transition: color var(--transition-fast);
}

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

a:active {
    color: var(--color-primary-active);
}

/* Strong and Bold */
strong, b {
    font-weight: var(--weight-semibold);
}

/* Code and Pre */
code, pre {
    font-family: var(--font-mono);
    font-size: 0.875em;
}

code {
    padding: 0.125rem 0.25rem;
    background-color: var(--bg-tertiary);
    border-radius: var(--radius-sm);
}

pre {
    padding: var(--space-md);
    background-color: var(--bg-tertiary);
    border-radius: var(--radius-md);
    overflow-x: auto;
}

/* Horizontal Rule */
hr {
    border: none;
    border-top: 1px solid var(--border-color);
    margin: var(--space-xl) 0;
}

/* Selection */
::selection {
    background-color: var(--color-primary-light);
    color: var(--text-primary);
}

/* Focus Outline */
:focus-visible {
    outline: 2px solid var(--border-interactive);
    outline-offset: 2px;
}

/* Scrollbar Styling (WebKit browsers) */
::-webkit-scrollbar {
    width: 12px;
    height: 12px;
}

::-webkit-scrollbar-track {
    background: var(--bg-secondary);
}

::-webkit-scrollbar-thumb {
    background: var(--border-strong);
    border-radius: var(--radius-full);
}

::-webkit-scrollbar-thumb:hover {
    background: var(--text-tertiary);
}

/* Firefox Scrollbar */
* {
    scrollbar-width: thin;
    scrollbar-color: var(--border-strong) var(--bg-secondary);
}