/* ==========================================================================
   Base - CSS Custom Properties (Design Tokens)
   ========================================================================== */

:root {
  color-scheme: light dark;
  /* Colors - Neutral */
  --color-white: #ffffff;
  --color-black: #000000;

  --color-gray-50: #f9fafb;
  --color-gray-100: #f3f4f6;
  --color-gray-200: #e5e7eb;
  --color-gray-300: #d1d5db;
  --color-gray-400: #9ca3af;
  --color-gray-500: #6b7280;
  --color-gray-600: #4b5563;
  --color-gray-700: #374151;
  --color-gray-800: #1f2937;
  --color-gray-900: #111827;

  /* Brand Theme Colors */
  --theme-primary: #2563eb;
  --theme-secondary: #0f766e;
  --theme-surface-tint: #eff6ff;

  /* Colors - Primary (Derived from Theme) */
  --color-primary-50: color-mix(in srgb, var(--theme-primary) 8%, white);
  --color-primary-100: color-mix(in srgb, var(--theme-primary) 15%, white);
  --color-primary-200: color-mix(in srgb, var(--theme-primary) 25%, white);
  --color-primary-300: color-mix(in srgb, var(--theme-primary) 40%, white);
  --color-primary-400: color-mix(in srgb, var(--theme-primary) 55%, white);
  --color-primary-500: color-mix(in srgb, var(--theme-primary) 70%, white);
  --color-primary-600: var(--theme-primary);
  --color-primary-700: color-mix(in srgb, var(--theme-primary) 78%, black);
  --color-primary-800: color-mix(in srgb, var(--theme-primary) 64%, black);
  --color-primary-900: color-mix(in srgb, var(--theme-primary) 50%, black);

  /* Colors - Secondary (Derived from Theme) */
  --color-secondary-100: color-mix(in srgb, var(--theme-secondary) 20%, white);
  --color-secondary-600: var(--theme-secondary);
  --color-secondary-700: color-mix(in srgb, var(--theme-secondary) 78%, black);

  /* Colors - Success (Green) */
  --color-success-500: #22c55e;
  --color-success-600: #16a34a;
  --color-success-700: #15803d;

  /* Colors - Warning (Yellow) */
  --color-warning-500: #eab308;
  --color-warning-600: #ca8a04;

  /* Colors - Danger (Red) */
  --color-danger-500: #ef4444;
  --color-danger-600: #dc2626;
  --color-danger-700: #b91c1c;

  /* Semantic Colors */
  --color-canvas: var(--color-white);
  --color-ink: var(--color-gray-900);
  --color-ink-light: var(--color-gray-600);
  --color-ink-lighter: var(--color-gray-400);
  --color-border: var(--color-gray-200);
  --color-border-dark: var(--color-gray-300);
  --color-link: var(--color-primary-700);
  --color-link-hover: var(--color-primary-800);
  --color-tinted-surface: var(--theme-surface-tint);
  --color-component-surface: #f5f4f2;
  --color-surface-subtle: var(--color-gray-50);
  --color-code-bg: var(--color-gray-100);
  --color-app-shell-bg: color-mix(in srgb, var(--theme-surface-tint) 35%, white);
  --color-switch-track-off: var(--color-gray-300);
  --color-switch-thumb: var(--color-white);

  --color-success-bg: #dcfce7;
  --color-success-border: #bbf7d0;
  --color-danger-bg: #fee2e2;
  --color-danger-border: #fecaca;
  --color-warning-bg: #fef9c3;
  --color-warning-border: #fef08a;
  --color-sidebar-handle-bg: #dfdcd5;
  --color-sidebar-handle-border: #c4c0b8;
  --color-sidebar-handle-hover: #d0cdc5;
  --sidebar-handle-shadow: 1px 2px 4px 0 rgba(180, 176, 168, 0.45);

  /* Typography - Font Families */
  --font-sans: "IBM Plex Sans", system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --font-heading: "CartridgeBold", var(--font-sans);
  --font-mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, monospace;

  /* Typography - 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 */

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

  /* Typography - Line Heights */
  --leading-none: 1;
  --leading-tight: 1.25;
  --leading-snug: 1.375;
  --leading-normal: 1.5;
  --leading-relaxed: 1.625;

  /* 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-8: 2rem;      /* 32px */
  --space-10: 2.5rem;   /* 40px */
  --space-12: 3rem;     /* 48px */

  /* Border Radius */
  --radius-sm: 0.25rem;
  --radius-md: 0.375rem;
  --radius-lg: 0.5rem;
  --radius-xl: 0.75rem;
  --radius-full: 9999px;

  /* Shadows */
  --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
  --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
  --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);

  /* Transitions */
  --transition-fast: 150ms ease;
  --transition-normal: 200ms ease;
  --transition-slow: 300ms ease;
}

/* Dark mode overrides */
@media (prefers-color-scheme: dark) {
  :root:not([data-color-scheme="light"]) {
    --color-canvas: var(--color-gray-900);
    --color-ink: var(--color-gray-100);
    --color-ink-light: var(--color-gray-400);
    --color-ink-lighter: var(--color-gray-500);
    --color-border: var(--color-gray-700);
    --color-border-dark: var(--color-gray-600);
    --color-component-surface: var(--color-gray-800);
    --color-surface-subtle: var(--color-gray-800);
    --color-code-bg: var(--color-gray-800);
    --color-app-shell-bg: color-mix(in srgb, var(--theme-surface-tint) 12%, var(--color-gray-900));
    --color-switch-track-off: var(--color-gray-700);
    --color-switch-thumb: var(--color-gray-100);
    --color-success-bg: color-mix(in srgb, var(--color-success-500) 24%, var(--color-gray-900));
    --color-success-border: color-mix(in srgb, var(--color-success-500) 42%, var(--color-gray-700));
    --color-danger-bg: color-mix(in srgb, var(--color-danger-500) 24%, var(--color-gray-900));
    --color-danger-border: color-mix(in srgb, var(--color-danger-500) 42%, var(--color-gray-700));
    --color-warning-bg: color-mix(in srgb, var(--color-warning-500) 24%, var(--color-gray-900));
    --color-warning-border: color-mix(in srgb, var(--color-warning-500) 42%, var(--color-gray-700));
    --color-tinted-surface: color-mix(in srgb, var(--theme-surface-tint) 8%, var(--color-gray-800));
    --color-sidebar-handle-bg: #39382f;
    --color-sidebar-handle-border: #2a2923;
    --color-sidebar-handle-hover: #454438;
    --sidebar-handle-shadow: 1px 2px 4px 0 rgba(0, 0, 0, 0.5);
    --feed-unread-tint: 12%;
    --feed-urgent-tint: 16%;
  }
}

:root[data-color-scheme="dark"] {
  --color-canvas: var(--color-gray-900);
  --color-ink: var(--color-gray-100);
  --color-ink-light: var(--color-gray-400);
  --color-ink-lighter: var(--color-gray-500);
  --color-border: var(--color-gray-700);
  --color-border-dark: var(--color-gray-600);
  --color-component-surface: var(--color-gray-800);
  --color-surface-subtle: var(--color-gray-800);
  --color-code-bg: var(--color-gray-800);
  --color-app-shell-bg: color-mix(in srgb, var(--theme-surface-tint) 12%, var(--color-gray-900));
  --color-switch-track-off: var(--color-gray-700);
  --color-switch-thumb: var(--color-gray-100);
  --color-success-bg: color-mix(in srgb, var(--color-success-500) 24%, var(--color-gray-900));
  --color-success-border: color-mix(in srgb, var(--color-success-500) 42%, var(--color-gray-700));
  --color-danger-bg: color-mix(in srgb, var(--color-danger-500) 24%, var(--color-gray-900));
  --color-danger-border: color-mix(in srgb, var(--color-danger-500) 42%, var(--color-gray-700));
  --color-warning-bg: color-mix(in srgb, var(--color-warning-500) 24%, var(--color-gray-900));
  --color-warning-border: color-mix(in srgb, var(--color-warning-500) 42%, var(--color-gray-700));
  --color-tinted-surface: color-mix(in srgb, var(--theme-surface-tint) 8%, var(--color-gray-800));
  --color-sidebar-handle-bg: #39382f;
  --color-sidebar-handle-border: #2a2923;
  --color-sidebar-handle-hover: #454438;
  --sidebar-handle-shadow: 1px 2px 4px 0 rgba(0, 0, 0, 0.5);
  --feed-unread-tint: 12%;
  --feed-urgent-tint: 16%;
}

:root[data-color-scheme="light"] {
  --color-canvas: var(--color-white);
  --color-ink: var(--color-gray-900);
  --color-ink-light: var(--color-gray-600);
  --color-ink-lighter: var(--color-gray-400);
  --color-border: var(--color-gray-200);
  --color-border-dark: var(--color-gray-300);
  --color-component-surface: #f5f4f2;
  --color-surface-subtle: var(--color-gray-50);
  --color-code-bg: var(--color-gray-100);
  --color-app-shell-bg: color-mix(in srgb, var(--theme-surface-tint) 35%, white);
  --color-switch-track-off: var(--color-gray-300);
  --color-switch-thumb: var(--color-white);
  --color-success-bg: #dcfce7;
  --color-success-border: #bbf7d0;
  --color-danger-bg: #fee2e2;
  --color-danger-border: #fecaca;
  --color-warning-bg: #fef9c3;
  --color-warning-border: #fef08a;
  --color-sidebar-handle-bg: #dfdcd5;
  --color-sidebar-handle-border: #c4c0b8;
  --color-sidebar-handle-hover: #d0cdc5;
  --sidebar-handle-shadow: 1px 2px 4px 0 rgba(180, 176, 168, 0.45);
}

/* ==========================================================================
   Base Element Styles
   ========================================================================== */

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  font-family: var(--font-sans);
  font-size: var(--text-base);
  line-height: var(--leading-normal);
  color: var(--color-ink);
  background-color: var(--color-canvas);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  margin: 0;
  padding: 0;
}

a {
  color: var(--color-link);
  text-decoration: none;
}

a:hover {
  color: var(--color-link-hover);
  text-decoration: underline;
}

h1, h2, h3, h4, h5, h6 {
  margin: 0 0 var(--space-4);
  font-family: var(--font-heading);
  font-synthesis: none;
  font-weight: var(--font-normal);
  line-height: var(--leading-tight);
  text-transform: uppercase;
}

h2 { font-size: var(--text-2xl); }
h3 { font-size: var(--text-xl); }
h4 { font-size: var(--text-lg); }

p {
  margin: 0 0 var(--space-4);
}

code {
  font-family: var(--font-mono);
  font-size: 0.875em;
  background: var(--color-code-bg);
  padding: 0.125em 0.25em;
  border-radius: var(--radius-sm);
}

.is-hidden {
  display: none !important;
}