Fix charging bugs, remove disabling charging since its not supported in HW

web/style.css

@@ -199,7 +199,6 @@
   .seg-btn:last-child { border-right:none; }
   .seg-btn.active { background:var(--accent); color:var(--bg); font-weight:bold; }
   .seg-btn:disabled { cursor:not-allowed; opacity:0.35; }
-  .charge-seg .seg-btn.active.off  { background:var(--dim);    color:#fff; }
   .charge-seg .seg-btn.active.slow { background:var(--warn);   color:var(--bg); }
   .charge-seg .seg-btn.active.fast { background:var(--accent2);color:#fff; }