diff --git a/index.html b/index.html
index a0c8f80..bb80a69 100644
--- a/index.html
+++ b/index.html
@@ -185,6 +185,26 @@
             opacity: .8;
             border-bottom: 1px solid #8886;
         }
+
+        /* Solution cards: each solve gets its own collapsible block so older
+       solutions stay viewable, newest on top. */
+        details.solution {
+            border: 1px solid #8884;
+            border-radius: 8px;
+            padding: .3rem .8rem;
+            margin-top: .8rem;
+        }
+
+        details.solution>summary {
+            font-weight: 600;
+            cursor: pointer;
+            padding: .3rem 0;
+        }
+
+        .pending {
+            opacity: .75;
+            margin-top: .8rem;
+        }
     </style>
 </head>
 
@@ -445,8 +465,20 @@
                         [upBoxes[u], " " + u]));
                 }
             }
-            type.onchange = renderUpgrades;
+            // Vat amounts only matter for Foundries; hide them otherwise and keep
+            // them as the card's last fields (before the actions).
+            const vatFields = [
+                field("Vat steel", vs),
+                field("Vat brass", vb),
+                field("Vat electrum", ve),
+            ];
+            function renderVats() {
+                const show = type.value === "foundry";
+                for (const f of vatFields) f.style.display = show ? "" : "none";
+            }
+            type.onchange = () => {renderUpgrades(); renderVats();};
             renderUpgrades();
+            renderVats();
 
             card._get = () => {
                 const o = {name: name.value, type: type.value};
@@ -469,14 +501,12 @@
                 field("Name", name),
                 field("Type", type),
                 field("Renown", renown),
-                field("Vat steel", vs),
-                field("Vat brass", vb),
-                field("Vat electrum", ve),
                 field("Upgrades (already installed)", upWrap),
                 checkField("Can renovate", reno),
                 field("Adjacent cities (csv of names)", adjacent),
                 field("Forced actions (turn:action, csv)", forced),
                 field("Avail turns (csv, blank=all)", avail),
+                ...vatFields,
                 el("div", {class: "card-actions"}, removeBtn(card)));
             document.getElementById("cities").append(card);
         }
@@ -497,11 +527,13 @@
             const forced = el("input", {value: "", placeholder: "0:Aridias"});
             const avail = el("input", {value: ""});
 
+            const bastionsField = field("Bastions (Baron only)", bastions);
+
             let nameEdited = !!a.name;
             name.oninput = () => {nameEdited = true;};
             function syncType() {
                 if (!nameEdited) name.value = type.value;
-                bastions.disabled = (type.value !== "Baron");
+                bastionsField.style.display = (type.value === "Baron") ? "" : "none";
                 desc.textContent = AGENT_DESC[type.value] || "";
             }
             type.onchange = syncType;
@@ -519,9 +551,9 @@
             card.append(
                 field("Agent", type),
                 field("Effect", desc),
-                field("Bastions (Baron only)", bastions),
                 field("Forced city (turn:city, csv)", forced),
                 field("Avail turns (csv, blank=all)", avail),
+                bastionsField,
                 el("div", {class: "card-actions"}, removeBtn(card)));
             document.getElementById("agents").append(card);
         }
@@ -645,16 +677,24 @@
             };
         }
 
+        // Each solve produces its own collapsible <details> card; older ones are
+        // kept (collapsed) so previous solutions stay viewable. solutionCount labels
+        // them in request order.
+        let solutionCount = 0;
+
         async function run() {
             const errBox = document.getElementById("error");
             const out = document.getElementById("output");
-            errBox.textContent = ""; out.innerHTML = "";
+            errBox.textContent = "";
+            // A placeholder card for this request, prepended so the newest is on top.
+            // It's replaced by the solution on success, or removed on error.
+            const pending = el("p", {class: "pending"}, "Solving…");
+            out.prepend(pending);
             let problem, time;
             try {
                 problem = buildProblem();
                 time = +document.getElementById("time").value;
-            } catch (e) {errBox.textContent = e.message; return;}
-            out.textContent = "Solving…";
+            } catch (e) {errBox.textContent = e.message; pending.remove(); return;}
             try {
                 const resp = await fetch("/solve", {
                     method: "POST",
@@ -662,15 +702,20 @@
                     body: JSON.stringify({problem, max_time_seconds: time}),
                 });
                 const data = await resp.json();
-                if (!resp.ok) {out.innerHTML = ""; errBox.textContent = data.error || "Server error"; return;}
-                renderSolution(data);
-            } catch (e) {out.innerHTML = ""; errBox.textContent = e.message;}
+                if (!resp.ok) {pending.remove(); errBox.textContent = data.error || "Server error"; return;}
+                renderSolution(data, pending);
+            } catch (e) {pending.remove(); errBox.textContent = e.message;}
         }
 
-        function renderSolution(s) {
-            const out = document.getElementById("output");
-            out.innerHTML = "";
-            out.append(el("h2", {}, "Solution"));
+        function renderSolution(s, placeholder) {
+            // Collapse any previously-shown solutions so the new one is the focus.
+            for (const d of document.querySelectorAll("#output details.solution")) d.open = false;
+
+            const n = ++solutionCount;
+            const details = el("details", {class: "solution", open: ""});
+            details.append(el("summary", {},
+                `Solution ${n} — ${s.status}, objective ${s.objective_value ?? "—"}`));
+            const out = details;
             out.append(el("p", {
                 html:
                     `<b>Status:</b> ${s.status} &nbsp; <b>Objective:</b> ${s.objective_value ?? "—"} &nbsp; ` +
@@ -709,6 +754,10 @@
                     ["Turn", "Converted into", "Amount"],
                     s.trade_conversions.map(c => [c.turn, c.resource, fmtNum(c.amount)])));
             }
+
+            // Swap the finished card in for this request's placeholder.
+            if (placeholder) placeholder.replaceWith(details);
+            else document.getElementById("output").prepend(details);
         }
 
         // Trim trailing ".0" so whole numbers read cleanly.