:root {
  /* Color System - Toy Camera Noir Palette */

  /* Base Colors - Darkroom inspired */
  --color-noir-black: #0a0a0a;
  --color-charcoal: #1a1a1a;
  --color-smoke: #2a2a2a;
  --color-slate: #3a3a3a;
  --color-ash: #4a4a4a;

  /* Light Colors - Film/Paper tones */
  --color-silver: #b8b8b8;
  --color-platinum: #d4d4d4;
  --color-paper: #e8e8e8;
  --color-white: #f5f5f5;

  /* Accent Colors - Light leak inspired */
  --color-amber-leak: rgba(255, 191, 105, 0.20);
  --color-cyan-leak: rgba(105, 191, 255, 0.12);
  --color-magenta-leak: rgba(255, 105, 191, 0.10);
  --color-ember: #e0a45a;
  --color-ember-bright: #f6cf86;
  --color-ember-dark: #a7742e;
  --color-accent: var(--color-ember);
  --color-accent-bright: var(--color-ember-bright);

  /* Cream / paper display tones (for headings) */
  --color-cream: #f3ecdc;
  --color-cream-dim: #d8cdb6;
  --color-heading: var(--color-cream);
  --color-black: #100b05;

  /* Feedback Colors */
  --color-success: #2ecc71;
  --color-success-bg: rgba(46, 204, 113, 0.15);
  --color-success-border: rgba(46, 204, 113, 0.3);
  --color-error: #e74c3c;
  --color-error-bg: rgba(231, 76, 60, 0.15);
  --color-error-border: rgba(231, 76, 60, 0.3);

  /* Semantic Colors */
  --color-bg-primary: var(--color-noir-black);
  --color-bg-secondary: var(--color-charcoal);
  --color-bg-tertiary: var(--color-smoke);
  --color-bg-frame: rgba(16, 16, 16, 0.92);
  --color-bg-frame-highlight: rgba(28, 28, 28, 0.92);

  --color-text-primary: var(--color-white);
  --color-text-secondary: var(--color-platinum);
  --color-text-muted: var(--color-silver);

  --color-border: var(--color-slate);
  --color-border-light: var(--color-ash);

  /* Typography */
  --font-sans: 'Inter', 'Noto Sans JP', 'Hiragino Sans', 'Hiragino Kaku Gothic ProN', sans-serif;
  --font-display: 'Fraunces', 'Shippori Mincho', 'Noto Serif JP', 'Hiragino Mincho ProN', 'YuMincho', serif;
  --font-mono: 'SF Mono', 'Monaco', 'Inconsolata', 'Fira Mono', monospace;

  /* Font Sizes */
  --text-xs: 0.75rem;    /* 12px */
  --text-sm: 0.875rem;   /* 14px */
  --text-base: 1rem;     /* 16px */
  --text-lg: 1.125rem;   /* 18px */
  --text-xl: 1.25rem;    /* 20px */
  --text-2xl: 1.5rem;    /* 24px */
  --text-3xl: 1.875rem;  /* 30px */
  --text-4xl: 2.25rem;   /* 36px */
  --text-5xl: 3rem;      /* 48px */
  --text-6xl: 3.75rem;   /* 60px */

  /* Fluid display sizes */
  --text-display: clamp(2.5rem, 1.2rem + 6.4vw, 5.5rem);   /* hero */
  --text-section: clamp(1.75rem, 1.2rem + 2.2vw, 2.75rem); /* section titles */

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

  /* Line Heights */
  --leading-tight: 1.2;
  --leading-normal: 1.6;
  --leading-relaxed: 1.8;

  /* Spacing */
  --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-7: 1.75rem;   /* 28px */
  --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-32: 8rem;     /* 128px */

  /* Layout */
  --container-sm: 640px;
  --container-md: 768px;
  --container-lg: 1024px;
  --container-xl: 1280px;
  --container-2xl: 1536px;

  --container-padding: clamp(1.875rem, 1.25rem + 2.8vw, 3rem);
  --page-padding-y: var(--space-8);
  --page-padding-x: var(--space-6);
  --header-height: 72px;
  /* Status-bar inset (viewport-fit=cover); 0 everywhere except notched iOS */
  --safe-top: env(safe-area-inset-top, 0px);
  --header-total: calc(var(--header-height) + var(--safe-top));
  --section-pad: clamp(4rem, 2.75rem + 5vw, 7rem);

  /* Border Radius */
  --radius-sm: 0.125rem;  /* 2px */
  --radius-md: 0.25rem;   /* 4px */
  --radius-lg: 0.5rem;    /* 8px */
  --radius-xl: 1rem;      /* 16px */
  --radius-2xl: 1.75rem;  /* 28px */

  /* Shadows - Subtle, film-inspired */
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.5);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.5), 0 2px 4px -1px rgba(0, 0, 0, 0.3);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.5), 0 4px 6px -2px rgba(0, 0, 0, 0.3);
  --shadow-frame: 0 24px 60px rgba(0, 0, 0, 0.6);

  /* Transitions */
  --transition-fast: 150ms ease-in-out;
  --transition-base: 250ms ease-in-out;
  --transition-slow: 350ms ease-in-out;

  /* Film Grain Effect */
  --grain-opacity: 0.04;

  /* Viewfinder Frame (for special sections) */
  --viewfinder-border: 2px solid var(--color-slate);
  --viewfinder-corner-size: 22px;

  /* Film Perforation (for backgrounds) */
  --perforation-size: 8px;
  --perforation-spacing: 16px;

  /* Frame Layout */
  --frame-max-width: 1200px;
  --frame-padding: var(--space-6);
  --frame-radius: var(--radius-2xl);
}

/* Responsive Typography */
@media (max-width: 1024px) {
  :root {
    --text-5xl: 2.5rem;   /* 40px */
    --text-6xl: 3.25rem;  /* 52px */

    --page-padding-y: var(--space-6);
    --frame-padding: var(--space-5);
    --header-height: 66px;
  }
}

@media (max-width: 768px) {
  :root {
    --text-3xl: 1.5rem;   /* 24px */
    --text-4xl: 1.875rem; /* 30px */
    --text-5xl: 2.25rem;  /* 36px */
    --text-6xl: 3rem;     /* 48px */

    --page-padding-y: var(--space-4);
    --frame-padding: var(--space-4);
    --frame-radius: var(--radius-xl);
    --header-height: 60px;
  }
}

@media (max-width: 540px) {
  :root {
    --text-4xl: 1.75rem; /* 28px */
    --text-5xl: 2rem;    /* 32px */
    --text-6xl: 2.5rem;  /* 40px */

    --page-padding-y: var(--space-2);
    --frame-padding: var(--space-2);
    --frame-radius: var(--radius-lg);
    --header-height: 54px;
  }
}

/* Reduced Motion Support */
@media (prefers-reduced-motion: reduce) {
  :root {
    --transition-fast: 0ms;
    --transition-base: 0ms;
    --transition-slow: 0ms;
  }

  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}