:root {
    /* Color System - Light mode */
    --color-primary: #1ac3c9;
    --color-primary-dark: #15a8ad;
    --color-primary-light: #45d0d5;

    --color-background: #ffffff;
    --color-surface: #f9f7f7;
    --color-surface-alt: #fcfcfc;

    --color-text: #2b1d2c;
    --color-text-light: #666666;
    --color-text-lighter: #888888;

    --color-border: #c4c3c3;
    --color-border-light: #e0e0e0;

    --color-shadow: rgba(43, 29, 44, 0.15);
    --color-shadow-light: rgba(43, 29, 44, 0.08);

    --color-success: #10b981;
    --color-warning: #f59e0b;
    --color-error: #ef4444;

    /* Typography */
    --font-family-base:
        "Open Sans", system-ui, -apple-system, Segoe UI, Roboto, Arial,
        "Noto Sans", sans-serif;
    --font-family-heading: var(--font-family-base);

    --font-weight-normal: 400;
    --font-weight-medium: 500;
    --font-weight-semibold: 600;
    --font-weight-bold: 700;

    --line-height-tight: 1.2;
    --line-height-normal: 1.6;
    --line-height-relaxed: 1.8;

    /* Spacing */
    --space-xs: 0.25rem;
    --space-sm: 0.5rem;
    --space-md: 1rem;
    --space-lg: 1.5rem;
    --space-xl: 2rem;
    --space-2xl: 3rem;
    --space-3xl: 4rem;

    /* Border Radius */
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 12px;
    --radius-xl: 16px;
    --radius-full: 9999px;

    /* Shadows */
    --shadow-sm: 0 1px 2px 0 var(--color-shadow);
    --shadow-md:
        0 4px 6px -1px var(--color-shadow),
        0 2px 4px -1px var(--color-shadow-light);
    --shadow-lg:
        0 10px 15px -3px var(--color-shadow),
        0 4px 6px -2px var(--color-shadow-light);
    --shadow-xl:
        0 20px 25px -5px var(--color-shadow),
        0 10px 10px -5px var(--color-shadow-light);
    --shadow-glow: 0 0 20px rgba(26, 195, 201, 0.15);

    /* Transitions */
    --transition-fast: 0.2s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-normal: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: 0.5s cubic-bezier(0.4, 0, 0.2, 1);

    /* Layout */
    --container-max-width: 1200px;
    --container-padding: 1rem;
    --header-height: 70px;

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

/* Dark mode */
@media (prefers-color-scheme: dark) {
    :root {
        --color-background: #1e1e1e;
        --color-surface: #2c2c2c;
        --color-surface-alt: #3a3a3a;

        --color-text: #e5e5e5;
        --color-text-light: #b0b0b0;
        --color-text-lighter: #888888;

        --color-border: #505050;
        --color-border-light: #404040;

        --color-shadow: rgba(0, 0, 0, 0.5);
        --color-shadow-light: rgba(0, 0, 0, 0.25);
    }
}

/* Print mode */
@media print {
    :root {
        --color-background: #ffffff;
        --color-surface: #fcfcfc;
        --color-surface-alt: #ffffff;
        --color-text: #2b1d2c;
        --color-text-light: #666666;
        --color-border: #c4c3c3;
        --color-border-light: #e0e0e0;
        --color-shadow: rgba(43, 29, 44, 0.15);
        --color-shadow-light: rgba(43, 29, 44, 0.08);
    }
}

/* Accessibility */
:focus-visible {
    outline: 2px solid var(--color-primary);
    outline-offset: 2px;
}

@media (prefers-reduced-motion: reduce) {
    * {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}