diff --git a/extension/src/vault/vault.css b/extension/src/vault/vault.css
index 270b73b..8d9f994 100644
--- a/extension/src/vault/vault.css
+++ b/extension/src/vault/vault.css
@@ -1396,6 +1396,281 @@ textarea {
   color: #484f58;
 }
 
+/* === 3-column shell === */
+.vault-shell {
+  display: flex;
+  height: 100vh;
+  overflow: hidden;
+  background: var(--bg-page, #0d1117);
+}
+
+.vault-sidebar {
+  width: 200px;
+  min-width: 200px;
+  display: flex;
+  flex-direction: column;
+  border-right: 1px solid var(--border, #30363d);
+  background: var(--bg-sidebar, #0d1117);
+  overflow-y: auto;
+  flex-shrink: 0;
+}
+
+.vault-list-pane {
+  flex: 1;
+  display: flex;
+  flex-direction: column;
+  overflow-y: auto;
+  min-width: 0;
+}
+
+.vault-drawer {
+  width: 440px;
+  min-width: 440px;
+  max-width: 440px;
+  border-left: 1px solid var(--border, #30363d);
+  background: var(--bg-elevated, #161b22);
+  overflow-y: auto;
+  transform: translateX(100%);
+  transition: transform 0.2s ease;
+  flex-shrink: 0;
+}
+
+.vault-drawer--open {
+  transform: translateX(0);
+}
+
+.vault-list-row {
+  display: flex;
+  align-items: center;
+  gap: 10px;
+  padding: 10px 16px;
+  cursor: pointer;
+  border-bottom: 1px solid var(--border-subtle, #21262d);
+  transition: background 0.1s;
+}
+
+.vault-list-row:hover { background: var(--bg-hover, #161b22); }
+
+.vault-list-row--selected {
+  background: var(--bg-selected, #1c2d41);
+  border-left: 2px solid var(--gold, #b8860b);
+}
+
+.vault-list-row__icon {
+  width: 32px;
+  height: 32px;
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  background: var(--bg-elevated, #161b22);
+  border-radius: 6px;
+  border: 1px solid var(--border, #30363d);
+  font-size: 14px;
+  flex-shrink: 0;
+}
+
+.vault-list-row--selected .vault-list-row__icon { border-color: var(--gold, #b8860b); }
+
+.vault-list-row__text { flex: 1; min-width: 0; }
+
+.vault-list-row__title {
+  font-size: 13px;
+  font-weight: 500;
+  overflow: hidden;
+  text-overflow: ellipsis;
+  white-space: nowrap;
+}
+
+.vault-list-row__subtitle {
+  font-size: 11px;
+  color: var(--text-muted, #8b949e);
+  overflow: hidden;
+  text-overflow: ellipsis;
+  white-space: nowrap;
+  margin-top: 1px;
+}
+
+.vault-list-row__age {
+  font-size: 10px;
+  color: var(--text-dim, #6e7681);
+  flex-shrink: 0;
+}
+
+/* Bottom sheet */
+.vault-bottom-sheet-scrim {
+  position: absolute;
+  inset: 0 0 0 200px;
+  background: rgba(0,0,0,0.5);
+  opacity: 0;
+  transition: opacity 0.2s;
+  pointer-events: none;
+  z-index: 100;
+}
+
+.vault-bottom-sheet-scrim--visible {
+  opacity: 1;
+  pointer-events: auto;
+}
+
+.vault-bottom-sheet {
+  position: absolute;
+  bottom: 0;
+  left: 200px;
+  right: 0;
+  background: var(--bg-elevated, #161b22);
+  border-top: 1px solid var(--border, #30363d);
+  border-radius: 12px 12px 0 0;
+  padding: 16px 24px 24px;
+  transform: translateY(100%);
+  transition: transform 0.25s ease;
+  z-index: 101;
+  max-height: 60vh;
+  overflow-y: auto;
+}
+
+.vault-bottom-sheet--open { transform: translateY(0); }
+
+.vault-bottom-sheet__handle {
+  width: 40px;
+  height: 4px;
+  background: var(--border, #30363d);
+  border-radius: 2px;
+  margin: 0 auto 16px;
+}
+
+.vault-bottom-sheet__title {
+  font-size: 14px;
+  font-weight: 600;
+  margin-bottom: 16px;
+  text-align: center;
+}
+
+.vault-type-grid {
+  display: grid;
+  grid-template-columns: repeat(auto-fill, minmax(100px, 1fr));
+  gap: 10px;
+}
+
+.vault-type-card {
+  display: flex;
+  flex-direction: column;
+  align-items: center;
+  justify-content: center;
+  padding: 12px 8px;
+  background: var(--bg-page, #0d1117);
+  border: 1px solid var(--border, #30363d);
+  border-radius: 8px;
+  cursor: pointer;
+  transition: border-color 0.15s;
+  gap: 6px;
+}
+
+.vault-type-card:hover { border-color: var(--gold, #b8860b); }
+
+.vault-type-card__icon { font-size: 28px; }
+.vault-type-card__name { font-size: 11px; color: var(--text-muted, #8b949e); }
+
+/* Drawer header and body */
+.vault-drawer__header {
+  display: flex;
+  align-items: center;
+  padding: 12px 16px;
+  border-bottom: 1px solid var(--border, #30363d);
+  gap: 8px;
+}
+
+.vault-drawer__type-pill {
+  font-size: 10px;
+  text-transform: uppercase;
+  letter-spacing: 0.05em;
+  padding: 2px 8px;
+  background: var(--bg-page, #0d1117);
+  border: 1px solid var(--border, #30363d);
+  border-radius: 4px;
+  color: var(--text-muted, #8b949e);
+}
+
+.vault-drawer__actions { display: flex; gap: 6px; margin-left: auto; }
+
+.vault-drawer__close {
+  background: transparent;
+  border: none;
+  cursor: pointer;
+  font-size: 16px;
+  color: var(--text-muted, #8b949e);
+  padding: 4px 6px;
+}
+
+.vault-drawer__body { padding: 20px 20px 16px; }
+
+.vault-drawer__title  { font-size: 18px; font-weight: 700; margin-bottom: 4px; }
+.vault-drawer__subtitle { font-size: 12px; color: var(--text-muted, #8b949e); margin-bottom: 16px; }
+
+.vault-drawer__field-grid {
+  display: grid;
+  grid-template-columns: 1fr 1fr;
+  gap: 12px;
+}
+
+.vault-drawer__field-grid > .vault-drawer__field--full { grid-column: 1 / -1; }
+
+.vault-drawer__field-label {
+  font-size: 10px;
+  text-transform: uppercase;
+  letter-spacing: 0.04em;
+  color: var(--text-muted, #8b949e);
+  margin-bottom: 2px;
+}
+
+.vault-drawer__field-value {
+  font-size: 13px;
+  word-break: break-all;
+}
+
+/* Category nav */
+.vault-category-row {
+  display: flex;
+  align-items: center;
+  gap: 8px;
+  width: 100%;
+  padding: 6px 12px;
+  background: transparent;
+  border: none;
+  cursor: pointer;
+  color: inherit;
+  font-size: 13px;
+  text-align: left;
+}
+
+.vault-category-row:hover { background: var(--bg-hover, #161b22); }
+.vault-category-row--active { background: var(--bg-selected, #1c2d41); }
+.vault-category-row__icon { font-size: 14px; flex-shrink: 0; }
+.vault-category-row__label { flex: 1; }
+.vault-category-row__count { font-size: 11px; color: var(--text-muted, #8b949e); }
+
+/* === Responsive === */
+@media (max-width: 960px) {
+  .vault-drawer {
+    position: absolute;
+    right: 0;
+    top: 0;
+    height: 100%;
+  }
+}
+
+@media (max-width: 720px) {
+  .vault-sidebar {
+    width: 48px;
+    min-width: 48px;
+  }
+  .vault-sidebar__category-label,
+  .vault-sidebar__category-count,
+  .vault-sidebar__nav-label {
+    display: none;
+  }
+  .vault-sidebar__nav-item { justify-content: center; padding: 10px 0; }
+}
+
 /* --- Lock screen (vault tab) --- */
 
 .vault-lock-screen {