/**
 * CSS Custom Properties (Design Tokens)
 * USA Web School Design System
 */

:root {
    /* ===== Brand Colors ===== */
    --color-navy: #000f6a;
    --color-burgundy: #6d0800;
    --color-green: #007203;
    --color-cream: #f8fafc;

    /* Primary Colors */
    --color-primary: var(--color-navy);
    --color-secondary: var(--color-burgundy);
    --color-accent: var(--color-green);
    --color-background: var(--color-cream);

    /* Semantic Colors */
    --color-success: var(--color-green);
    --color-warning: #d97706;
    --color-error: #dc2626;
    --color-info: var(--color-navy);

    /* Neutral Scale */
    --color-white: #ffffff;
    --color-off-white: var(--color-cream);
    --color-light-gray: #d1d5db;
    --color-gray: #6b7280;
    --color-dark-gray: #374151;
    --color-charcoal: #1f2937;
    --color-black: #000000;

    /* Text Colors */
    --color-text-primary: var(--color-charcoal);
    --color-text-secondary: var(--color-dark-gray);
    --color-text-muted: #4b5563; /* gray-600, 7.0:1 on white — WCAG AA compliant */
    --color-text-on-dark: var(--color-white);
    --color-text-heading: var(--color-navy);
    --color-text-link: var(--color-burgundy);
    --color-text-link-hover: var(--color-navy);

    /* ===== Typography ===== */
    /* Font Families */
    --font-heading: 'Source Serif Pro', Georgia, serif;
    --font-body: 'Source Sans Pro', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --font-mono: 'Courier New', Courier, monospace;

    /* Font Weights */
    --font-weight-regular: 400;
    --font-weight-semibold: 600;
    --font-weight-bold: 700;

    /* WCAG 2.1 AA — Minimum font size floor (nothing below this) */
    --font-size-minimum: 0.75rem;  /* 12px — absolute floor for all visible text */

    /* Mobile Type Scale (320px - 767px) */
    --font-size-hero: 2rem;        /* 32px */
    --font-size-h1: 1.75rem;       /* 28px */
    --font-size-h2: 1.5rem;        /* 24px */
    --font-size-h3: 1.25rem;       /* 20px */
    --font-size-h4: 1.125rem;      /* 18px */
    --font-size-large: 1.125rem;   /* 18px */
    --font-size-base: 1rem;        /* 16px */
    --font-size-small: 0.875rem;   /* 14px */
    --font-size-caption: 0.75rem;  /* 12px — equals --font-size-minimum */

    /* Line Heights */
    --line-height-tight: 1.2;
    --line-height-snug: 1.3;
    --line-height-normal: 1.4;
    --line-height-relaxed: 1.5;
    --line-height-loose: 1.6;

    /* Letter Spacing */
    --letter-spacing-tight: -0.02em;
    --letter-spacing-normal: 0;
    --letter-spacing-wide: 0.02em;

    /* ===== Spacing System (4px grid) ===== */
    --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 */
    --space-5xl: 8rem;      /* 128px */

    /* ===== Shadows ===== */
    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.1);
    --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.15);
    --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.2);
    --shadow-donate: 0 4px 12px rgba(109, 8, 0, 0.3);

    /* ===== Border Radius ===== */
    --radius-sm: 6px;
    --radius-md: 8px;
    --radius-lg: 12px;
    --radius-xl: 16px;
    --radius-pill: 24px;
    --radius-full: 9999px;

    /* ===== Transitions ===== */
    --transition-fast: 150ms ease-out;
    --transition-base: 200ms ease-in-out;
    --transition-slow: 300ms ease-in-out;

    /* ===== Breakpoints (for reference in media queries) ===== */
    --breakpoint-mobile: 320px;
    --breakpoint-tablet: 768px;
    --breakpoint-desktop: 1024px;
    --breakpoint-large: 1440px;

    /* ===== Container Widths ===== */
    --container-mobile: 100%;
    --container-tablet: 720px;
    --container-desktop: 960px;
    --container-large: 1200px;

    /* ===== Z-Index Scale ===== */
    --z-base: 0;
    --z-dropdown: 10;
    --z-sticky: 20;
    --z-fixed: 30;
    --z-modal-backdrop: 40;
    --z-modal: 50;
    --z-popover: 60;
    --z-tooltip: 70;
}

/* ===== Tablet & Desktop Overrides (768px+) ===== */
@media (min-width: 768px) {
    :root {
        --font-size-hero: 3rem;        /* 48px */
        --font-size-h1: 2.5rem;        /* 40px */
        --font-size-h2: 2rem;          /* 32px */
        --font-size-h3: 1.5rem;        /* 24px */
        --font-size-h4: 1.25rem;       /* 20px */
        --font-size-large: 1.25rem;    /* 20px */
        --font-size-base: 1.125rem;    /* 18px */
        --font-size-small: 1rem;       /* 16px */
        --font-size-caption: 0.875rem; /* 14px */
    }
}

/* ===== Reduced Motion Preference ===== */
@media (prefers-reduced-motion: reduce) {
    :root {
        --transition-fast: 0ms;
        --transition-base: 0ms;
        --transition-slow: 0ms;
    }
}