:root{--primary-color: #06b6d4}body{transition:background .2s,color .2s,font-family .2s}body.dark{background:#111827;color:#f3f4f6}body{background:#f3f4f6;color:#111827}.btn-primary{background:var(--primary-color);color:#fff}input:focus,select:focus{outline-color:var(--primary-color);border-color:var(--primary-color)}