/* ============================================
   CSS Custom Properties (Variables)
   ============================================ */

:root {
    /* ===== Color Scheme ===== */
    --color-scheme: light;

    /* ===== Primary Colors ===== */
    --primary: #007AFF;
    --primary-hover: #0051D5;
    --primary-dark: #0051D5;
    --primary-subtle: rgba(0, 122, 255, 0.15);

    /* ===== Accent Colors - iOS 18 ===== */
    --secondary: #5E5CE6;
    --accent: #34C759;
    --accent-green: #34C759;
    --accent-purple: #AF52DE;
    --accent-orange: #FF9500;
    --accent-red: #FF3B30;
    --warning: #FF9500;
    --danger: #FF3B30;

    /* ===== Backgrounds - Light ===== */
    --bg-primary: #FFFFFF;
    --bg-secondary: #F2F2F7;
    --bg-tertiary: #E5E5EA;
    --bg-elevated: rgba(255, 255, 255, 0.85);

    /* ===== Text - Light ===== */
    --text-primary: #000000;
    --text-secondary: #3C3C43;
    --text-tertiary: #8E8E93;
    --text-quaternary: #C7C7CC;

    /* ===== Borders & Glass ===== */
    --border: #38383A;
    --border-primary: rgba(60, 60, 67, 0.12);
    --border-secondary: rgba(60, 60, 67, 0.08);
    --glass-bg: rgba(255, 255, 255, 0.72);
    --glass-border: rgba(255, 255, 255, 0.3);
    --blur-amount: 40px;

    /* ===== Shadows - iOS 18 Enhanced ===== */
    --shadow: rgba(0, 0, 0, 0.5);
    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.06),
                 0 1px 2px rgba(0, 0, 0, 0.04);
    --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.07),
                 0 2px 4px rgba(0, 0, 0, 0.05),
                 0 0 1px rgba(0, 0, 0, 0.04);
    --shadow-lg: 0 10px 20px rgba(0, 0, 0, 0.1),
                 0 6px 12px rgba(0, 0, 0, 0.08),
                 0 0 1px rgba(0, 0, 0, 0.05);
    --shadow-xl: 0 20px 40px rgba(0, 0, 0, 0.12),
                 0 10px 20px rgba(0, 0, 0, 0.1),
                 0 0 1px rgba(0, 0, 0, 0.08);
    --shadow-2xl: 0 25px 50px rgba(0, 0, 0, 0.15),
                  0 12px 24px rgba(0, 0, 0, 0.12),
                  0 0 1px rgba(0, 0, 0, 0.1);

    /* ===== Spacing - 8px Grid System ===== */
    --spacing-xs: 4px;
    --spacing-sm: 8px;
    --spacing-md: 16px;
    --spacing-lg: 24px;
    --spacing-xl: 32px;
    --spacing-2xl: 48px;
    --spacing-3xl: 64px;
    --spacing-4xl: 80px;
    --spacing-5xl: 96px;

    /* ===== Border Radius - macOS Sonoma ===== */
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-xl: 20px;
    --radius-2xl: 24px;
    --radius-3xl: 28px;
    --radius-full: 9999px;

    /* ===== Transitions - Apple Timing Functions ===== */
    --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);
    --transition-bounce: 500ms cubic-bezier(0.68, -0.55, 0.265, 1.55);

    /* Enhanced easing curves */
    --ease-spring: cubic-bezier(0.68, -0.55, 0.265, 1.55);
    --ease-out-expo: cubic-bezier(0.16, 1, 0.3, 1);
    --ease-in-out-smooth: cubic-bezier(0.65, 0, 0.35, 1);

    /* ===== Z-Index Layers ===== */
    --z-base: 0;
    --z-dropdown: 100;
    --z-sticky: 200;
    --z-overlay: 1000;
    --z-modal: 1100;
    --z-popover: 1200;
    --z-toast: 1300;

    /* ===== Typography ===== */
    --font-sans: 'DM Sans', -apple-system, BlinkMacSystemFont, 'SF Pro Display',
                 'SF Pro Text', 'Segoe UI', 'Helvetica Neue', Arial, sans-serif;
    --font-display: 'Syne', var(--font-sans);

    --font-size-xs: 0.75rem;    /* 12px */
    --font-size-sm: 0.875rem;   /* 14px */
    --font-size-base: 1rem;     /* 16px */
    --font-size-lg: 1.125rem;   /* 18px */
    --font-size-xl: 1.25rem;    /* 20px */
    --font-size-2xl: 1.5rem;    /* 24px */
    --font-size-3xl: 1.875rem;  /* 30px */
    --font-size-4xl: 2.25rem;   /* 36px */
    --font-size-5xl: 3rem;      /* 48px */
}

/* ============================================
   Dark Mode
   ============================================ */

[data-theme="dark"] {
    --color-scheme: dark;

    /* Primary Colors - Dark Mode */
    --primary: #0A84FF;
    --primary-hover: #409CFF;
    --primary-dark: #0066CC;
    --primary-subtle: rgba(10, 132, 255, 0.2);

    /* Accent Colors - Dark Mode */
    --accent-green: #32D74B;
    --accent-purple: #BF5AF2;
    --accent-orange: #FF9F0A;
    --accent-red: #FF453A;
    --accent: #32D74B;
    --warning: #FF9F0A;
    --danger: #FF453A;

    /* Backgrounds - Dark Mode */
    --bg-primary: #000000;
    --bg-secondary: #1C1C1E;
    --bg-tertiary: #2C2C2E;
    --bg-elevated: rgba(28, 28, 30, 0.85);

    /* Text - Dark Mode */
    --text-primary: #FFFFFF;
    --text-secondary: #EBEBF5;
    --text-tertiary: #AEAEB2;
    --text-quaternary: #636366;

    /* Borders & Glass - Dark Mode */
    --border: #38383A;
    --border-primary: rgba(84, 84, 88, 0.65);
    --border-secondary: rgba(84, 84, 88, 0.3);
    --glass-bg: rgba(28, 28, 30, 0.72);
    --glass-border: rgba(255, 255, 255, 0.1);

    /* Shadows - Dark Mode Enhanced */
    --shadow: rgba(0, 0, 0, 0.5);
    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.4),
                 0 1px 2px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.5),
                 0 2px 4px rgba(0, 0, 0, 0.4),
                 0 0 1px rgba(0, 0, 0, 0.3);
    --shadow-lg: 0 10px 20px rgba(0, 0, 0, 0.6),
                 0 6px 12px rgba(0, 0, 0, 0.5),
                 0 0 1px rgba(0, 0, 0, 0.4);
    --shadow-xl: 0 20px 40px rgba(0, 0, 0, 0.7),
                 0 10px 20px rgba(0, 0, 0, 0.6),
                 0 0 1px rgba(0, 0, 0, 0.5);
    --shadow-2xl: 0 25px 50px rgba(0, 0, 0, 0.8),
                  0 12px 24px rgba(0, 0, 0, 0.7),
                  0 0 1px rgba(0, 0, 0, 0.6);
}