:root {
    --color-primary: #667eea;
    --color-primary-hover: #5a6fd8;
    --color-secondary: #6c757d;
    --color-secondary-hover: #5a6268;
    --color-text-dark: #2c3e50;
    --color-text-medium: #495057;
    --color-text-light: #6c757d;
    --color-bg-light: #f8f9fa;
    --color-border: #e9ecef;
    --color-white: white;

    --font-family-base: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    --font-family-mono: 'Courier New', monospace;

    --space-xs: 5px;
    --space-sm: 10px;
    --space-md: 15px;
    --space-lg: 20px;
    --space-xl: 30px;
    --space-xxl: 40px;

    --border-radius-sm: 5px;
    --border-radius-md: 8px;
    --border-radius-lg: 15px;

    --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 10px 30px rgba(0, 0, 0, 0.08);
    --shadow-lg: 0 20px 40px rgba(0, 0, 0, 0.1);
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: var(--font-family-base);
    background: linear-gradient(135deg, var(--color-primary) 0%, #764ba2 100%);
    min-height: 100vh;
    padding: var(--space-lg);
    line-height: 1.6;
    color: var(--color-text-medium);
}

.hidden {
    display: none !important;
}

a {
    color: var(--color-primary);
    text-decoration: none;
    transition: color 0.3s;
}

a:hover {
    text-decoration: underline;
}