:root{
  --color-primary:#0B6EFF;
  --color-primary-dark:#084FB0;
  --color-secondary:#0E7490;
  --color-bg:#FFFFFF;
  --color-surface:#F5F7FA;
  --color-ink:#0E1B2E;
  --color-muted:#64748B;
  --radius:0.75rem;
  --shadow-card:0 10px 30px rgba(11,110,255,0.08);
  --font-sans:'Inter','Helvetica Neue',Arial,sans-serif;
}

html{scroll-behavior:smooth;}
body{font-family:var(--font-sans);}

/* Screen-reader-only helper (fallback: Tailwind Play CDN may be blocked) */
.sr-only{
  position:absolute;
  width:1px;height:1px;
  padding:0;margin:-1px;
  overflow:hidden;
  clip:rect(0,0,0,0);
  clip-path:inset(50%);
  white-space:nowrap;
  border:0;
}

/* Smooth anchor offset for sticky header */
section[id]{scroll-margin-top:4rem;}

/* Details/summary marker */
details summary{cursor:pointer;}
details summary::-webkit-details-marker{display:none;}
details summary::after{content:'▾';float:right;color:var(--color-primary);}
details[open] summary::after{content:'▴';}