diff --git a/frontend/src/app/markets/[id]/page.tsx b/frontend/src/app/markets/[id]/page.tsx
index 8557ad4..871068f 100644
--- a/frontend/src/app/markets/[id]/page.tsx
+++ b/frontend/src/app/markets/[id]/page.tsx
@@ -279,12 +279,19 @@ export default function MarketDetailPage({
                   </div>
                 </div>
 
-                {claiming ? (
-                  <TxProgress step={claimStage === "idle" ? "building" : claimStage} />
-                ) : (
-                  <Button onClick={handleClaim} variant="primary" fullWidth>
-                    Claim Rewards
-                  </Button>
+                <Button
+                  onClick={handleClaim}
+                  disabled={claiming}
+                  loading={claiming}
+                  variant="primary"
+                  fullWidth
+                >
+                  {claiming ? "Claiming..." : "Claim Rewards"}
+                </Button>
+                {claiming && (
+                  <div className="mt-3">
+                    <TxProgress step={claimStage === "idle" ? "building" : claimStage} />
+                  </div>
                 )}
                 {claimError && (
                   <p className="text-sm text-accent-red mt-2">{claimError}</p>
diff --git a/frontend/src/components/ui/Button.tsx b/frontend/src/components/ui/Button.tsx
index cf5ade0..9f62614 100644
--- a/frontend/src/components/ui/Button.tsx
+++ b/frontend/src/components/ui/Button.tsx
@@ -1,13 +1,15 @@
 import React from "react";
+import { FiLoader } from "react-icons/fi";
 
 type Variant = "primary" | "secondary" | "ghost";
 
 interface ButtonProps extends React.ButtonHTMLAttributes<HTMLButtonElement> {
   variant?: Variant;
   fullWidth?: boolean;
+  loading?: boolean;
 }
 
-export default function Button({ variant = "primary", fullWidth = false, className, children, ...rest }: ButtonProps) {
+export default function Button({ variant = "primary", fullWidth = false, loading = false, className, children, ...rest }: ButtonProps) {
   const base = "inline-flex items-center justify-center rounded-2xl font-semibold transition-transform duration-150";
   const variants: Record<Variant, string> = {
     primary: "btn-primary",
@@ -15,10 +17,11 @@ export default function Button({ variant = "primary", fullWidth = false, classNa
     ghost: "bg-transparent text-slate-200 hover:text-white",
   };
 
-  const classes = `${base} ${variants[variant]} ${fullWidth ? "w-full" : ""} ${className ?? ""}`.trim();
+  const classes = `${base} ${variants[variant]} ${fullWidth ? "w-full" : ""} ${loading ? "opacity-70 cursor-wait" : ""} ${className ?? ""}`.trim();
 
   return (
-    <button {...rest} className={classes}>
+    <button {...rest} disabled={rest.disabled || loading} className={classes}>
+      {loading && <FiLoader className="w-4 h-4 mr-2 animate-spin shrink-0" />}
       {children}
     </button>
   );
diff --git a/frontend/src/hooks/useToast.tsx b/frontend/src/hooks/useToast.tsx
index 8a2328f..f930bb4 100644
--- a/frontend/src/hooks/useToast.tsx
+++ b/frontend/src/hooks/useToast.tsx
@@ -43,10 +43,11 @@ export function ToastProvider({ children }: { children: ReactNode }) {
   return (
     <ToastContext.Provider value={{ showToast }}>
       {children}
-      {/* Narrow viewports: bottom safe-area, full usable width. sm+: top-right stack. */}
+      {/* Toast container: bottom on mobile (safe-area aware), top-right on desktop.
+          Uses max-w-[calc(100vw-1rem)] so toasts never overflow on narrow viewports. */}
       <div
         className="fixed z-[200] pointer-events-none flex flex-col gap-2
-          left-3 right-3 bottom-[max(1rem,env(safe-area-inset-bottom))]
+          left-2 right-2 bottom-[max(0.75rem,env(safe-area-inset-bottom,0.75rem))]
           sm:left-auto sm:right-4 sm:bottom-auto sm:top-4 sm:w-auto sm:max-w-sm"
       >
         {toasts.map((t) => (
diff --git a/frontend/src/utils/helpers.ts b/frontend/src/utils/helpers.ts
index 3f28ea7..ad3a424 100644
--- a/frontend/src/utils/helpers.ts
+++ b/frontend/src/utils/helpers.ts
@@ -56,15 +56,23 @@ export function timeUntil(timestamp: number): string {
   return `${diff}s`;
 }
 
+// ── Timestamp Normalisation ─────────────────────────────────────────────────
+
 /**
- * Normalize a Unix timestamp that may be seconds or milliseconds to ms.
- * Values below ~1e12 are almost certainly seconds; above are ms.
+ * Normalize a positive Unix timestamp supplied in seconds or milliseconds to ms.
+ * Returns NaN for invalid / out-of-range values so callers can display a fallback.
  */
 export function toTimestampMs(timestamp: number): number {
-  if (!Number.isFinite(timestamp)) return Date.now();
-  return timestamp < 1e12 ? timestamp * 1000 : timestamp;
+  if (!Number.isFinite(timestamp) || timestamp <= 0) return Number.NaN;
+  const timestampMs =
+    timestamp < MILLISECOND_TIMESTAMP_THRESHOLD
+      ? timestamp * 1_000
+      : timestamp;
+  return timestampMs <= MAX_DATE_TIMESTAMP_MS ? timestampMs : Number.NaN;
 }
 
+// ── Date / Time Formatting (locale-aware, viewer timezone) ──────────────────
+
 const DATE_TIME_OPTIONS: Intl.DateTimeFormatOptions = {
   year: "numeric",
   month: "short",
@@ -81,133 +89,65 @@ const TIME_OPTIONS: Intl.DateTimeFormatOptions = {
 };
 
 /**
- * Format a Unix timestamp (seconds) to a locale-aware date/time string.
+ * Format a Unix timestamp (seconds or ms) to a locale-aware date/time string.
  * Uses the viewer's browser locale and local timezone automatically.
  *
  * Example (en-GB): "12 Jul 2026, 14:30 GMT+1"
  * Example (en-US): "Jul 12, 2026, 10:30 AM EDT"
  */
-/** Normalize a positive Unix timestamp supplied in seconds or milliseconds. */
-export function toTimestampMs(timestamp: number): number {
-  if (!Number.isFinite(timestamp) || timestamp <= 0) return Number.NaN;
-  const timestampMs =
-    timestamp < MILLISECOND_TIMESTAMP_THRESHOLD
-      ? timestamp * 1_000
-      : timestamp;
-  return timestampMs <= MAX_DATE_TIMESTAMP_MS ? timestampMs : Number.NaN;
-}
-
-/** Format a timestamp in the viewer's timezone, including its timezone label. */
 export function formatDate(
   timestamp: number,
   locale?: Intl.LocalesArgument,
   options: Intl.DateTimeFormatOptions = {}
 ): string {
-  if (!Number.isFinite(timestamp) || timestamp <= 0) return "—";
-  // Guard against accidental millisecond values (> year 2100 in seconds ≈ 4_102_444_800)
-  const ms = timestamp > 4_102_444_800 ? timestamp : timestamp * 1000;
+  const timestampMs = toTimestampMs(timestamp);
+  if (!Number.isFinite(timestampMs)) return INVALID_TIMESTAMP;
+
   return new Intl.DateTimeFormat(locale, {
     ...DATE_TIME_OPTIONS,
     ...options,
-  }).format(new Date(ms));
+  }).format(new Date(timestampMs));
 }
 
 /**
- * Format a Unix timestamp to a locale-aware time-only string.
+ * Format a Unix timestamp (seconds or ms) to a locale-aware time-only string.
  */
 export function formatTime(
   timestamp: number,
   locale?: Intl.LocalesArgument,
-  options?: Intl.DateTimeFormatOptions
+  options: Intl.DateTimeFormatOptions = {}
 ): string {
-  if (!Number.isFinite(timestamp) || timestamp <= 0) return "—";
-  const ms = timestamp > 4_102_444_800 ? timestamp : timestamp * 1000;
+  const timestampMs = toTimestampMs(timestamp);
+  if (!Number.isFinite(timestampMs)) return INVALID_TIMESTAMP;
+
   return new Intl.DateTimeFormat(locale, {
     ...TIME_OPTIONS,
     ...options,
-  }).format(new Date(ms));
+  }).format(new Date(timestampMs));
 }
 
 /**
  * Format an event timestamp (milliseconds) to a locale-aware date+time string.
- * Use this for MarketEvent.timestamp — it is already in milliseconds.
+ * Use this for MarketEvent.timestamp — it is already in milliseconds, do NOT multiply by 1000.
  */
 export function formatEventTime(timestampMs: number): string {
-  if (!Number.isFinite(timestampMs) || timestampMs <= 0) return "—";
-  return new Date(timestampMs).toLocaleString(undefined, DATE_TIME_OPTIONS);
-}
-
-/**
- * Return a human-readable relative time string from a Unix timestamp (seconds).
- * Uses the viewer's locale via Intl.RelativeTimeFormat.
- *
- * Examples: "2 hours ago", "3 days ago", "just now"
- */
-export function timeAgo(timestamp: number): string {
-  if (!Number.isFinite(timestamp) || timestamp <= 0) return "—";
-  const ms = timestamp > 4_102_444_800 ? timestamp : timestamp * 1000;
-  const diffSeconds = Math.floor((Date.now() - ms) / 1000);
-
-  if (diffSeconds < 5) return "just now";
-
-  const rtf = new Intl.RelativeTimeFormat(undefined, { numeric: "auto" });
-
-  const thresholds: [number, Intl.RelativeTimeFormatUnit][] = [
-    [60, "second"],
-    [3_600, "minute"],
-    [86_400, "hour"],
-    [604_800, "day"],
-    [2_592_000, "week"],
-    [31_536_000, "month"],
-  ];
-
-  for (const [limit, unit] of thresholds) {
-    if (diffSeconds < limit) {
-      const idx = thresholds.findIndex(([l]) => l === limit);
-      const prev = idx > 0 ? thresholds[idx - 1] : [1, "second"] as const;
-      const divisor = prev[0];
-      return rtf.format(-Math.floor(diffSeconds / divisor), unit);
-    }
-  }
-
-  return rtf.format(-Math.floor(diffSeconds / 31_536_000), "year");
-}
-
-/**
- * Calculate a winner's payout from a prediction market.
- * payout = (userNetBet / winningSideTotal) × totalPool
-  const timestampMs = toTimestampMs(timestamp);
-  if (!Number.isFinite(timestampMs)) return INVALID_TIMESTAMP;
-
-  return new Intl.DateTimeFormat(locale, {
+  if (!Number.isFinite(timestampMs) || timestampMs <= 0) return INVALID_TIMESTAMP;
+  return new Date(timestampMs).toLocaleString(undefined, {
     year: "numeric",
     month: "short",
     day: "numeric",
     hour: "2-digit",
     minute: "2-digit",
     timeZoneName: "short",
-    ...options,
-  }).format(new Date(timestampMs));
-}
-
-/** Format only the local time portion of a timestamp, with its timezone label. */
-export function formatTime(
-  timestamp: number,
-  locale?: Intl.LocalesArgument,
-  options: Intl.DateTimeFormatOptions = {}
-): string {
-  const timestampMs = toTimestampMs(timestamp);
-  if (!Number.isFinite(timestampMs)) return INVALID_TIMESTAMP;
-
-  return new Intl.DateTimeFormat(locale, {
-    hour: "2-digit",
-    minute: "2-digit",
-    timeZoneName: "short",
-    ...options,
-  }).format(new Date(timestampMs));
+  });
 }
 
-/** Format a timestamp relative to now while accepting seconds or milliseconds. */
+/**
+ * Return a human-readable relative time string from a Unix timestamp (seconds or ms).
+ * Uses the viewer's locale via Intl.RelativeTimeFormat.
+ *
+ * Examples: "2 hours ago", "3 days ago", "just now"
+ */
 export function timeAgo(
   timestamp: number,
   locale?: Intl.LocalesArgument
@@ -239,24 +179,11 @@ export function timeAgo(
   );
 }
 
-/** Format an event timestamp (milliseconds) to a locale-aware date+time string.
- * Use this for `MarketEvent.timestamp` – it is already in milliseconds, do NOT multiply by 1000. */
-export function formatEventTime(timestampMs: number): string {
-  if (!Number.isFinite(timestampMs) || timestampMs <= 0) return INVALID_TIMESTAMP;
-  return new Date(timestampMs).toLocaleString(undefined, {
-    year: "numeric",
-    month: "short",
-    day: "numeric",
-    hour: "2-digit",
-    minute: "2-digit",
-    timeZoneName: "short",
-  });
-}
+// ── Market Calculations ─────────────────────────────────────────────────────
 
-/** Calculate a winner's payout from a prediction market.
- *
+/**
+ * Calculate a winner's payout from a prediction market.
  * payout = (userNetBet / winningSideTotal) × totalPool
- *
  * All values in XLM (not stroops).
  */
 export function calculatePayout(
@@ -268,12 +195,7 @@ export function calculatePayout(
   return (userNetBet / winningSideTotal) * totalPool;
 }
 
-/**
- * Calculate YES/NO odds percentages from net totals.
- * Returns { yesPercent, noPercent } — each 0-100.
-/** Calculate YES/NO odds percentages from net totals.
- * Returns { yesPercent, noPercent } – each 0-100.
- */
+/** Calculate YES/NO odds percentages from net totals. Returns { yesPercent, noPercent } – each 0-100. */
 export function calculateOdds(
   totalYes: number,
   totalNo: number
@@ -284,9 +206,8 @@ export function calculateOdds(
   return { yesPercent, noPercent: 100 - yesPercent };
 }
 
-/**
- * Build a Stellar Expert explorer URL for transactions, accounts, or contracts.
- */
+// ── Display Helpers ─────────────────────────────────────────────────────────
+
 /** Convert basis points to a percentage string. */
 export function bpsToPercent(bps: number): string {
   return `${bps / 100}%`;
@@ -298,11 +219,6 @@ export function explorerUrl(
   id: string,
   network: "public" | "testnet" = "public"
 ): string {
-  const base =
-    network === "testnet"
-      ? "https://stellar.expert/explorer/testnet"
-      : "https://stellar.expert/explorer/public";
-  return `${base}/${type}/${id}`;
   const base = `https://stellar.expert/explorer/${network}`;
   switch (type) {
     case "tx":