add built in scanner

public/css/style.css

@@ -590,7 +590,7 @@ tr:hover {
   background: linear-gradient(135deg, var(--card-bg) 0%, #0d2618 100%);
 }
 
-[data-theme="dark"] a:not(.btn) {
+[data-theme="dark"] a:not(.btn):not(.scanner-fab) {
   color: var(--primary);
 }
 
@@ -800,3 +800,45 @@ tr:hover {
     min-height: 36px;
   }
 }
+
+/* ── Floating QR Scanner FAB ──────────────────────────────── */
+.scanner-fab {
+  position: fixed;
+  bottom: 1.5rem;
+  right: 1.5rem;
+  width: 60px;
+  height: 60px;
+  border-radius: 50%;
+  background: var(--primary);
+  color: #000;
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  box-shadow: 0 4px 14px rgba(0,0,0,0.25);
+  text-decoration: none;
+  z-index: 100;
+  transition: transform 0.15s ease, box-shadow 0.15s ease;
+}
+
+.scanner-fab:hover {
+  transform: scale(1.1);
+  box-shadow: 0 6px 20px rgba(0,0,0,0.3);
+  color: #fff;
+}
+
+.scanner-fab:active {
+  transform: scale(0.95);
+}
+
+/* ── Scanner disclaimer on home page ─────────────────────── */
+.scanner-disclaimer {
+  background: var(--card-bg);
+  border: 1px solid var(--border);
+  border-left: 4px solid var(--primary);
+  border-radius: 8px;
+  padding: 1rem;
+}
+
+[data-theme="dark"] .scanner-disclaimer {
+  border-left-color: var(--primary);
+}