Mobile nav and drafting setup

assets/css/app.css

@@ -159,6 +159,22 @@ html, body {
 @media (max-width: 640px) {
   .mx-root { grid-template-columns: 1fr; }
   .mx-sidebar { display: none; }
+  /* space for fixed bottom nav */
+  .mx-main { padding-bottom: 72px; }
+  /* hide inline compose on mobile — the overlay handles it */
+  .mx-compose-wrapper { display: none; }
+  /* tighten card spacing */
+  .mx-feed { padding: 0.625rem 0.625rem; gap: 0.5rem; }
+  .mx-tweet { padding: 0.875rem 0.875rem; }
+  /* truncate long email addresses */
+  .mx-tweet-handle {
+    overflow: hidden;
+    text-overflow: ellipsis;
+    white-space: nowrap;
+    max-width: 180px;
+  }
+  .mx-header { padding: 0.75rem 1rem; }
+  .mx-detail { padding: 0.875rem 1rem; }
 }
 
 /* ── Sidebar ── */
@@ -802,3 +818,144 @@ html, body {
   background: var(--mx-border);
   margin: 4px 0;
 }
+
+/* ─────────────────────────────────────────────────────────────────────────────
+   Mobile bottom navigation bar
+   Only shown at ≤640 px (sidebar is hidden at that breakpoint).
+───────────────────────────────────────────────────────────────────────────── */
+.mx-mobile-nav {
+  display: none;
+  position: fixed;
+  bottom: 0;
+  left: 0;
+  right: 0;
+  z-index: 50;
+  height: 60px;
+  align-items: center;
+  justify-content: space-around;
+  background: color-mix(in oklch, var(--mx-bg) 92%, transparent);
+  backdrop-filter: blur(16px);
+  -webkit-backdrop-filter: blur(16px);
+  border-top: 1px solid var(--mx-border);
+  /* respect iPhone home indicator */
+  padding-bottom: env(safe-area-inset-bottom, 0px);
+}
+
+@media (max-width: 640px) {
+  .mx-mobile-nav { display: flex; }
+}
+
+.mx-mobile-nav-item {
+  display: flex;
+  flex: 1;
+  flex-direction: column;
+  align-items: center;
+  justify-content: center;
+  gap: 3px;
+  color: var(--mx-muted);
+  text-decoration: none;
+  font-size: 0.65rem;
+  font-weight: 500;
+  padding: 0.25rem 0;
+  transition: color 0.15s;
+  -webkit-tap-highlight-color: transparent;
+}
+
+.mx-mobile-nav-item--active { color: var(--mx-accent); }
+
+.mx-mobile-nav-item svg {
+  flex-shrink: 0;
+}
+
+/* Centred compose button — raised pill */
+.mx-mobile-nav-compose {
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  flex-shrink: 0;
+  width: 48px;
+  height: 48px;
+  border-radius: 50%;
+  background: var(--mx-accent);
+  color: #fff;
+  border: none;
+  cursor: pointer;
+  box-shadow: 0 4px 16px color-mix(in oklch, var(--mx-accent) 55%, transparent);
+  transition: background 0.15s, transform 0.12s, box-shadow 0.15s;
+  -webkit-tap-highlight-color: transparent;
+}
+
+.mx-mobile-nav-compose:hover {
+  background: var(--mx-accent2);
+  box-shadow: 0 6px 20px color-mix(in oklch, var(--mx-accent) 65%, transparent);
+  transform: scale(1.06);
+}
+
+.mx-mobile-nav-compose:active { transform: scale(0.94); }
+
+/* ─────────────────────────────────────────────────────────────────────────────
+   Mobile compose overlay (full-screen drafting page)
+   Hidden on desktop — only the mobile nav can trigger it.
+───────────────────────────────────────────────────────────────────────────── */
+@keyframes mx-overlay-in {
+  from { opacity: 0; transform: translateY(28px); }
+  to   { opacity: 1; transform: translateY(0); }
+}
+
+.mx-compose-overlay {
+  display: none;
+}
+
+@media (max-width: 640px) {
+  .mx-compose-overlay {
+    display: flex;
+    flex-direction: column;
+    position: fixed;
+    inset: 0;
+    z-index: 100;
+    background: var(--mx-bg);
+    animation: mx-overlay-in 0.22s cubic-bezier(0.34, 1.1, 0.64, 1);
+  }
+}
+
+.mx-compose-overlay-header {
+  display: flex;
+  align-items: center;
+  justify-content: space-between;
+  padding: 1rem 1.25rem;
+  border-bottom: 1px solid var(--mx-border);
+  background: color-mix(in oklch, var(--mx-bg) 85%, transparent);
+  backdrop-filter: blur(12px);
+  -webkit-backdrop-filter: blur(12px);
+  position: sticky;
+  top: 0;
+  z-index: 1;
+}
+
+.mx-compose-overlay-title {
+  font-family: 'Instrument Serif', Georgia, serif;
+  font-size: 1.125rem;
+  font-style: italic;
+  letter-spacing: -0.01em;
+  color: var(--mx-fg);
+}
+
+.mx-compose-overlay-cancel {
+  background: none;
+  border: none;
+  color: var(--mx-fg2);
+  font-size: 0.9rem;
+  font-family: inherit;
+  cursor: pointer;
+  padding: 0.25rem 0;
+  min-width: 60px;
+  transition: color 0.15s;
+}
+
+.mx-compose-overlay-cancel:hover { color: var(--mx-fg); }
+
+.mx-compose-overlay-body {
+  flex: 1;
+  overflow-y: auto;
+  padding: 1.25rem;
+}