:root {
    /* Colors - 既存のMUIテーマから移植 */
    --color-primary-light: #4FD1C5;
    --color-primary-main: #127C71;
    --color-primary-dark: #0A5D54;
    --color-secondary-light: #FFD166;
    --color-secondary-main: #FF9F1C;
    --color-secondary-dark: #E67E22;

    /* Status Colors */
    --color-success: #4CAF50;
    --color-warning: #FF9800;
    --color-error: #F44336;
    --color-info: #127C71;

    /* Neutral Colors */
    --color-background: #F8FAFB;
    --color-paper: #FFFFFF;
    --color-text-primary: #1A202C;
    --color-text-secondary: #718096;
    --color-divider: #E2E8F0;

    /* Typography - Cabin font */
    --font-family-base: 'Cabin', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    --font-weight-light: 300;
    --font-weight-regular: 400;
    --font-weight-medium: 600;
    --font-weight-bold: 700;

    /* Font Sizes - Modular Scale (1.25) */
    --font-size-h1: 3.052rem;    /* 48.83px */
    --font-size-h2: 2.441rem;    /* 39.06px */
    --font-size-h3: 1.953rem;    /* 31.25px */
    --font-size-h4: 1.563rem;    /* 25px */
    --font-size-h5: 1.25rem;     /* 20px */
    --font-size-h6: 1rem;        /* 16px */
    --font-size-body: 1rem;      /* 16px */
    --font-size-small: 0.875rem; /* 14px */

    /* Line Heights */
    --line-height-tight: 1.2;
    --line-height-normal: 1.5;
    --line-height-relaxed: 1.75;

    /* Spacing - 8px base */
    --spacing-xs: 4px;
    --spacing-sm: 8px;
    --spacing-md: 16px;
    --spacing-lg: 24px;
    --spacing-xl: 32px;
    --spacing-2xl: 48px;
    --spacing-3xl: 64px;
    --spacing-4xl: 96px;

    /* Border Radius */
    --radius-none: 0;
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 12px;
    --radius-xl: 16px;
    --radius-2xl: 24px;
    --radius-full: 9999px;

    /* Transitions */
    --transition-fast: 150ms ease;
    --transition-normal: 250ms ease;
    --transition-slow: 350ms ease;

    /* Shadows */
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.08);
    --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.12);
    --shadow-lg: 0 12px 24px rgba(0, 0, 0, 0.15);
    --shadow-xl: 0 20px 32px rgba(0, 0, 0, 0.18);

    /* Z-index */
    --z-base: 1;
    --z-dropdown: 1000;
    --z-sticky: 1100;
    --z-fixed: 1200;
    --z-modal: 1300;
    --z-popover: 1400;
    --z-tooltip: 1500;

    /* Breakpoints (for reference in media queries) */
    --breakpoint-xs: 0px;
    --breakpoint-sm: 600px;
    --breakpoint-md: 960px;
    --breakpoint-lg: 1280px;
    --breakpoint-xl: 1920px;

    /* Container Max Width */
    --container-max-width: 1200px;
    --container-padding: var(--spacing-xl);
}

/* Dark Mode Support (Optional) */
@media (prefers-color-scheme: dark) {
    :root {
        --color-background: #1A202C;
        --color-paper: #2D3748;
        --color-text-primary: #F7FAFC;
        --color-text-secondary: #CBD5E0;
        --color-divider: #4A5568;
    }
}