:root {
    /* ═══════════════════════════════════════════════════════════
       ⚡ QUICK WIDTH CONTROLS - Adjust these easily!
       Change these numbers to make everything wider/narrower
       ═══════════════════════════════════════════════════════════ */
    
    --page-base-width: 1400px;      /* 👈 MAIN CONTROL: Book spreads width */
    --article-base-width: 900px;    /* 👈 Articles and centered content */
    --note-desk-width: 1600px;      /* 👈 Notes desk maximum width */
    
    /* Colors - Academic Palette */
    --color-bg: #f5f7fa;
    --color-surface: rgba(255, 255, 255, 0.98);
    --color-paper: #faf8f3;
    --color-border: rgba(175, 190, 210, 0.3);
    --color-border-light: rgba(175, 190, 210, 0.15);
    --color-text-primary: #2C3E50;
    --color-text-secondary: #5D6F80;
    --color-text-tertiary: #8A9EA8;
    --color-accent: #6B8EA8;
    --color-accent-hover: #5D6F80;
    --color-header-shadow: rgba(140, 160, 180, 0.06);
    
    --header-height: 88px;
    
    /* Note colors - Soft academic tones */
    --note-yellow: #fff8c9;
    --note-blue: #e8f2fb;
    --note-green: #eaf5ec;
    --note-peach: #fdebe3;
    
    /* Typography */
    --font-serif: 'Playfair Display', serif;
    --font-sans: 'Inter', sans-serif;
    --font-sans-ui: 'Inter', sans-serif;
    --font-body: 'Source Serif Pro', serif;
    
    /* Spacing */
    --space-xs: 0.5rem;
    --space-sm: 1rem;
    --space-md: 1.5rem;
    --space-lg: 2.5rem;
    --space-xl: 4rem;
    --space-2xl: 6rem;
    
    /* Layout - Flexible Width System (uses controls above) */
    --container-narrow: 680px;              /* Articles, single column */
    --container-medium: var(--article-base-width);   /* Uses article control */
    --container-wide: 1140px;               /* Standard width */
    --container-wider: var(--page-base-width);       /* Uses main control */
    --container-max: var(--note-desk-width);         /* Uses desk control */
    --container-full: 100%;                 /* Full bleed option */
    
    /* Page Width Controls (for fine-tuning) */
    --page-width-default: 520px;    /* Default book page width */
    --page-width-wide: 680px;       /* Wider book pages */
    --article-width-default: 65ch;  /* Default article (65 characters) */
    --article-width-wide: 75ch;     /* Wider article */
    
    /* Shadows - Gentle academic feel */
    --shadow-gentle: 0 8px 40px rgba(140, 160, 180, 0.08);
    --shadow-hover: 0 12px 50px rgba(140, 160, 180, 0.12);
    
    /* Transitions */
    --transition-base: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}