/* ==========================================================================
   CSS Custom Properties (Variables)
   Centrální definice barev, typografie, spacing a breakpointů
   ========================================================================== */

:root {
    /* ======================================================================
       COLORS - Barevná paleta
       ====================================================================== */

    /* Primary - Tanix Blue (akční prvky, CTA) */
    --color-primary: #03A9F3;
    --color-primary-hover: #0290d1;
    --color-primary-active: #0278af;
    --color-primary-light: #e1f5fe;
    --color-primary-lighter: #f0fafd;

    /* Secondary - Tanix Purple */
    --color-secondary: #ab8ce4;
    --color-secondary-hover: #9a7bd3;
    --color-secondary-light: #f3eefb;

    /* Neutrals - Grayscale */
    --color-white: #FFFFFF;
    --color-gray-50: #F5F8FA;
    --color-gray-100: #EDF2F5;
    --color-gray-200: #D8E1E8;
    --color-gray-300: #B8C7D1;
    --color-gray-400: #87A4AE;
    --color-gray-500: #5C7A8A;
    --color-gray-600: #445E6E;
    --color-gray-700: #334857;
    --color-gray-800: #233545;
    --color-gray-900: #17243D;
    --color-black: #0D1520;

    /* Utility Accent Colors (pro ikony energií) */
    --color-electric: #F59E0B;    /* Elektřina - žlutá/amber */
    --color-gas: #EF4444;         /* Plyn - červená */
    --color-water: #3B82F6;       /* Voda - modrá */
    --color-heat: #F97316;        /* Teplo - oranžová */

    /* Status Colors */
    --color-success: #00c292;
    --color-success-light: #d9f5ee;
    --color-warning: #fec107;
    --color-warning-light: #fef8e1;
    --color-error: #EF4444;
    --color-error-light: #FEE2E2;
    --color-info: #03a9f3;
    --color-info-light: #e1f5fe;

    /* ======================================================================
       TYPOGRAPHY - Typografie
       ====================================================================== */

    /* Font Families */
    --font-primary: 'Noto Sans', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
    --font-mono: 'Fira Code', 'Consolas', 'Monaco', monospace;

    /* Font Sizes */
    --text-xs: 0.875rem;     /* 14px */
    --text-sm: 1rem;         /* 16px */
    --text-base: 1.125rem;   /* 18px */
    --text-lg: 1.25rem;      /* 20px */
    --text-xl: 1.375rem;     /* 22px */
    --text-2xl: 1.5rem;      /* 24px */
    --text-3xl: 1.875rem;    /* 30px */
    --text-4xl: 2.25rem;     /* 36px */
    --text-5xl: 3rem;        /* 48px */
    --text-6xl: 3.75rem;     /* 60px */

    /* Font Weights */
    --font-light: 300;
    --font-normal: 400;
    --font-medium: 500;
    --font-semibold: 600;
    --font-bold: 700;
    --font-extrabold: 800;

    /* Line Heights */
    --leading-none: 1;
    --leading-tight: 1.25;
    --leading-snug: 1.375;
    --leading-normal: 1.5;
    --leading-relaxed: 1.625;
    --leading-loose: 2;

    /* Letter Spacing */
    --tracking-tighter: -0.05em;
    --tracking-tight: -0.025em;
    --tracking-normal: 0;
    --tracking-wide: 0.025em;
    --tracking-wider: 0.05em;

    /* ======================================================================
       SPACING - Mezery (8px grid systém)
       ====================================================================== */

    --space-0: 0;
    --space-1: 0.25rem;      /* 4px */
    --space-2: 0.5rem;       /* 8px */
    --space-3: 0.75rem;      /* 12px */
    --space-4: 1rem;         /* 16px */
    --space-5: 1.25rem;      /* 20px */
    --space-6: 1.5rem;       /* 24px */
    --space-8: 2rem;         /* 32px */
    --space-10: 2.5rem;      /* 40px */
    --space-12: 3rem;        /* 48px */
    --space-14: 3.5rem;      /* 56px */
    --space-16: 4rem;        /* 64px */
    --space-20: 5rem;        /* 80px */
    --space-24: 6rem;        /* 96px */
    --space-28: 7rem;        /* 112px */
    --space-32: 8rem;        /* 128px */

    /* ======================================================================
       LAYOUT - Layout specifikace
       ====================================================================== */

    /* Container */
    --container-max: 1280px;
    --container-padding: 1.5rem;      /* 24px - mobile */
    --container-padding-lg: 2rem;     /* 32px - desktop */

    /* Section Padding */
    --section-padding-y: 4rem;        /* 64px - mobile */
    --section-padding-y-lg: 6rem;     /* 96px - desktop */

    /* Header */
    --header-height: 100px;
    --header-height-scrolled: 64px;

    /* ======================================================================
       BORDERS & RADIUS
       ====================================================================== */

    --radius-none: 0;
    --radius-sm: 0.25rem;    /* 4px */
    --radius-md: 0.375rem;   /* 6px */
    --radius-lg: 0.5rem;     /* 8px */
    --radius-xl: 0.75rem;    /* 12px */
    --radius-2xl: 1rem;      /* 16px */
    --radius-3xl: 1.5rem;    /* 24px */
    --radius-full: 9999px;   /* pill shape */

    --border-width: 1px;
    --border-width-2: 2px;

    /* ======================================================================
       SHADOWS
       ====================================================================== */

    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
    --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.1), 0 8px 10px -6px rgb(0 0 0 / 0.1);
    --shadow-2xl: 0 25px 50px -12px rgb(0 0 0 / 0.25);

    /* Header shadow */
    --shadow-header: 0 1px 3px 0 rgb(0 0 0 / 0.1), 0 1px 2px -1px rgb(0 0 0 / 0.1);

    /* Card hover shadow */
    --shadow-card-hover: 0 20px 40px -10px rgb(0 0 0 / 0.15);

    /* Colored shadows for modern look */
    --shadow-primary: 0 10px 40px -10px rgba(3, 169, 243, 0.4);
    --shadow-primary-lg: 0 20px 60px -15px rgba(3, 169, 243, 0.5);
    --shadow-secondary: 0 10px 40px -10px rgba(171, 140, 228, 0.4);

    /* Glassmorphism */
    --glass-bg: rgba(255, 255, 255, 0.7);
    --glass-bg-dark: rgba(255, 255, 255, 0.1);
    --glass-border: rgba(255, 255, 255, 0.3);
    --glass-blur: 20px;

    /* Card Design System */
    --card-bg: rgba(255, 255, 255, 0.85);
    --card-bg-hover: rgba(255, 255, 255, 0.95);
    --card-border: 1px solid rgba(255, 255, 255, 0.6);
    --card-border-hover: 1px solid rgba(3, 169, 243, 0.2);
    --card-radius: var(--radius-2xl);
    --card-blur: blur(20px);
    --card-shadow:
        0 4px 24px rgba(0, 0, 0, 0.06),
        0 1px 2px rgba(0, 0, 0, 0.04),
        inset 0 1px 0 rgba(255, 255, 255, 0.8);
    --card-shadow-hover:
        0 16px 48px rgba(3, 169, 243, 0.12),
        0 4px 12px rgba(0, 0, 0, 0.06),
        inset 0 1px 0 rgba(255, 255, 255, 0.9);
    --card-lift: -4px;

    /* Gradients */
    --gradient-primary: linear-gradient(135deg, #03A9F3 0%, #ab8ce4 100%);
    --gradient-hero: linear-gradient(135deg, #667eea 0%, #764ba2 50%, #f093fb 100%);
    --gradient-warm: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
    --gradient-cool: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%);
    --gradient-mesh: radial-gradient(at 40% 20%, rgba(3, 169, 243, 0.15) 0px, transparent 50%),
                     radial-gradient(at 80% 0%, rgba(171, 140, 228, 0.15) 0px, transparent 50%),
                     radial-gradient(at 0% 50%, rgba(245, 158, 11, 0.1) 0px, transparent 50%),
                     radial-gradient(at 80% 50%, rgba(0, 194, 146, 0.1) 0px, transparent 50%),
                     radial-gradient(at 0% 100%, rgba(3, 169, 243, 0.1) 0px, transparent 50%);

    /* ======================================================================
       TRANSITIONS & ANIMATIONS
       ====================================================================== */

    --transition-fast: 150ms ease;
    --transition-base: 200ms ease;
    --transition-slow: 300ms ease;
    --transition-slower: 500ms ease;

    /* Easing functions */
    --ease-in: cubic-bezier(0.4, 0, 1, 1);
    --ease-out: cubic-bezier(0, 0, 0.2, 1);
    --ease-in-out: cubic-bezier(0.4, 0, 0.2, 1);
    --ease-bounce: cubic-bezier(0.68, -0.55, 0.265, 1.55);

    /* ======================================================================
       Z-INDEX SCALE
       ====================================================================== */

    --z-dropdown: 100;
    --z-sticky: 200;
    --z-fixed: 300;
    --z-modal-backdrop: 400;
    --z-modal: 500;
    --z-popover: 600;
    --z-tooltip: 700;
}

/* ==========================================================================
   BREAKPOINT MEDIA QUERIES (pro reference v komentářích)

   --breakpoint-sm: 640px;   // Small devices
   --breakpoint-md: 768px;   // Tablets
   --breakpoint-lg: 1024px;  // Desktops
   --breakpoint-xl: 1280px;  // Large desktops
   --breakpoint-2xl: 1440px; // Extra large
   ========================================================================== */
