/* ==========================================================================
   Design tokens + minimal reset — extracted from the Dickson Engineering
   design system (dicksonengineering.com/assets/css/styles.css) so this tool
   is self-contained and doesn't depend on any sibling site's stylesheet.
   Keep in sync by hand if the source palette changes.
   ========================================================================== */
:root {
  /* Core palette */
  --color-charcoal:        #1B1F23;
  --color-charcoal-raised: #23282D;
  --color-graphite:        #3A4149;
  --color-steel:           #838C94;
  --color-steel-light:     #B7BEC4;
  --color-paper:           #F7F8F8;
  --color-paper-dim:       #ECEEEF;
  --color-white:           #FFFFFF;

  /* Accent — steel blue, used for interactive elements and technical linework */
  --color-accent:          #2C6E96;
  --color-accent-strong:   #1F5474;
  --color-accent-bright:   #5B9BC2;
  --color-accent-wash:     #E9F1F6;

  /* Used sparingly for validation/error states only */
  --color-error:           #A33B3B;
  --color-error-wash:      #FBEDEC;

  /* Type */
  --font-sans: 'IBM Plex Sans', -apple-system, BlinkMacSystemFont, 'Segoe UI', Helvetica, Arial, sans-serif;
  --font-mono: 'IBM Plex Mono', ui-monospace, SFMono-Regular, Consolas, 'Liberation Mono', monospace;

  --step--1: 0.875rem;
  --step-0:  1rem;

  /* Spacing scale */
  --space-1: 0.25rem;
  --space-2: 0.5rem;
  --space-3: 0.75rem;
  --space-4: 1rem;
  --space-5: 1.5rem;
  --space-6: 2rem;
  --space-7: 3rem;

  /* Structure */
  --radius: 3px;
  --border-hair: 1px solid var(--color-graphite);
  --border-hair-light: 1px solid #D8DCDE;
  --focus-ring: 2px solid var(--color-accent-bright);

  --ease: cubic-bezier(0.4, 0, 0.2, 1);
}

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

body {
  margin: 0;
  font-family: var(--font-sans);
  font-size: var(--step-0);
  line-height: 1.65;
  color: var(--color-charcoal);
  background: var(--color-paper);
  -webkit-font-smoothing: antialiased;
}

a { color: var(--color-accent-strong); text-decoration-thickness: 1px; text-underline-offset: 2px; }
a:hover { color: var(--color-accent); }

a:focus-visible,
button:focus-visible,
input:focus-visible,
textarea:focus-visible,
select:focus-visible {
  outline: var(--focus-ring);
  outline-offset: 2px;
}

/* Shared site-wide footer credit -- used on the hub and every tool page. */
.bt-footer {
  max-width: 560px;
  margin: var(--space-6) auto 0;
  padding: var(--space-5) var(--space-5) 0;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--color-steel);
  text-align: center;
}
.bt-footer a { color: var(--color-steel); }
.bt-footer a:hover { color: var(--color-accent-strong); }