diff --git a/dashboard/src/decisions.md b/dashboard/src/decisions.md
index e23c8f5..029addf 100644
--- a/dashboard/src/decisions.md
+++ b/dashboard/src/decisions.md
@@ -330,7 +330,13 @@ if (filtered.length === 0) {
 } else {
   display(html`<div class="dec-list">${filtered.map(d => {
     const border  = STATUS_BORDER[d.status] ?? "#ccc";
-    const snippet = (d.description || d.rationale || "").slice(0, 200);
+    const _desc = d.description || "";
+    const _rat  = d.rationale || "";
+    const _primary = _desc || _rat;
+    const snippet = _primary.slice(0, 200);
+    // Expandable when text is truncated, or when both fields exist (the
+    // collapsed view only shows one of them).
+    const _needsExpand = _primary.length > 200 || (_desc && _rat && _desc !== _rat);
     const due     = fmtDate(d.deadline);
     const decided = fmtDate(d.decided_at);
     const overdue = isOverdue(d.deadline);
@@ -375,7 +381,18 @@ if (filtered.length === 0) {
         ${_isOpen ? html`<button class="dec-resolve-btn" onclick=${onResolve}>Resolve</button>` : ""}
       </div>
       <div class="dec-title">${d.title}</div>
-      ${snippet ? html`<div class="dec-snippet">${snippet}${snippet.length < (d.description || d.rationale || "").length ? "…" : ""}</div>` : ""}
+      ${_primary ? (_needsExpand
+        ? html`<details class="dec-expand">
+            <summary>
+              <span class="dec-snippet dec-snippet-collapsed">${snippet}${_primary.length > 200 ? "…" : ""}</span>
+              <span class="dec-more"></span>
+            </summary>
+            <div class="dec-fulltext">
+              ${_desc ? html`<div class="dec-fulltext-section"><div class="dec-fulltext-label">Description</div><div class="dec-snippet">${_desc}</div></div>` : ""}
+              ${_rat  ? html`<div class="dec-fulltext-section"><div class="dec-fulltext-label">Rationale</div><div class="dec-snippet">${_rat}</div></div>` : ""}
+            </div>
+          </details>`
+        : html`<div class="dec-snippet">${_primary}</div>`) : ""}
       ${d.decided_by ? html`<div class="dec-resolved-by">✓ ${d.decided_by}${decided ? " · " + decided : ""}</div>` : ""}
       ${d.escalation_note && !["resolved", "superseded"].includes(d.status) ? html`<div class="dec-escalation-note">${d.escalation_note}</div>` : ""}
     </div>`;
@@ -458,6 +475,18 @@ if (escalated.length > 0) {
 .dec-title { font-weight: 600; font-size: 0.95rem; margin-bottom: 0.2rem; }
 .dec-snippet { font-size: 0.82rem; color: var(--theme-foreground-muted); line-height: 1.45; white-space: pre-wrap; }
 .dec-resolved-by { font-size: 0.78rem; color: #22c55e; margin-top: 0.3rem; }
+
+/* ── Expandable full text ─────────────────────────────────────────────────── */
+.dec-expand summary { list-style: none; cursor: pointer; }
+.dec-expand summary::-webkit-details-marker { display: none; }
+.dec-expand[open] .dec-snippet-collapsed { display: none; }
+.dec-more::after { content: "Show full text ▾"; }
+.dec-expand[open] .dec-more::after { content: "Show less ▴"; }
+.dec-more { display: inline-block; margin-left: 0.35rem; font-size: 0.72rem; font-weight: 600; color: steelblue; white-space: nowrap; }
+.dec-more:hover { text-decoration: underline; }
+.dec-expand[open] .dec-more { display: block; margin: 0.15rem 0 0.35rem; }
+.dec-fulltext-section + .dec-fulltext-section { margin-top: 0.5rem; }
+.dec-fulltext-label { font-size: 0.65rem; font-weight: 700; text-transform: uppercase; letter-spacing: 0.06em; color: var(--theme-foreground-faint, #aaa); margin-bottom: 0.1rem; }
 .dec-escalation-note { font-size: 0.78rem; color: #b45309; margin-top: 0.3rem; background: #fef3c7; border-radius: 4px; padding: 0.25rem 0.5rem; }
 
 /* ── Resolve button ───────────────────────────────────────────────────────── */