Style Strike ticker: single column, currency symbols, Danish formatting, sats display

Show 54€ equivalent in sats with dark blue styling, light gray background,
and Danish number formatting for BTC/USDT and BTC/EUR values.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/clj/pmagnus/btcprice/web/routes/ws_proxy.clj

@@ -102,21 +102,42 @@
 
 ;; --- Strike rendering ---
 
-(def ^:private strike-pairs ["BTC/USDT" "BTC/EUR" "USDT/EUR" "EUR/BTC"])
+(def ^:private strike-pairs
+  [["BTC/USDT" "$"]
+   ["BTC/EUR"  "\u20AC"]
+   ["USDT/EUR" ""]
+   ["EUR/BTC"  ""]])
+
+(defn- format-strike-amount [prefix amount]
+  (if amount
+    (let [v (double (bigdec amount))]
+      (case prefix
+        "$"      (str prefix (da-fmt "%,.2f" v))
+        "\u20AC" (str prefix (da-fmt "%,.2f" v))
+        amount))
+    "\u2014"))
+
+(defn- eur-to-sats [rates]
+  (when-let [eur-btc (get rates "EUR/BTC")]
+    (long (* 54 (double (bigdec eur-btc)) 100000000))))
 
 (defn- strike-json->html [text]
-  (let [rates (json/read-str text)]
+  (let [rates (json/read-str text)
+        sats  (eur-to-sats rates)]
     (str "<div id=\"strike-display\">"
-         "<div class=\"bg-white rounded-2xl shadow-sm border border-gray-200 p-6\">"
-         "<p class=\"text-center text-sm font-bold text-gray-500 mb-3\">Strike Ticker</p>"
-         "<div class=\"grid grid-cols-2 gap-x-6 gap-y-1\">"
+         "<div class=\"rounded-2xl shadow-sm border border-gray-200 p-6\" style=\"background:#f3f4f6;\">"
+         (if sats
+           (str "<p class=\"text-center text-2xl font-bold mb-3\" style=\"color:#1e3a5f;\">"
+                (da-fmt "%,d" sats) " <span style=\"color:#1e3a5f;\">sats</span></p>")
+           "")
+         "<div style=\"display:grid;grid-template-columns:1fr;row-gap:0.25rem;\">"
          (apply str
-           (for [pair strike-pairs
+           (for [[pair prefix] strike-pairs
                  :let [amount (get rates pair)]]
-             (str "<div class=\"flex justify-between items-center py-1\">"
+             (str "<div style=\"display:flex;justify-content:space-between;align-items:center;padding:0.25rem 0;\">"
                   "<span class=\"text-sm text-gray-500\">" pair "</span>"
                   "<span class=\"text-sm font-bold text-gray-900\">"
-                  (or amount "\u2014")
+                  (format-strike-amount prefix amount)
                   "</span></div>")))
          "</div></div></div>")))