diff --git a/shared/components/rstack-app-switcher.ts b/shared/components/rstack-app-switcher.ts
index 0ad1613..3da8a95 100644
--- a/shared/components/rstack-app-switcher.ts
+++ b/shared/components/rstack-app-switcher.ts
@@ -362,6 +362,7 @@ export class RStackAppSwitcher extends HTMLElement {
 			<style>${STYLES}</style>
 			<div class="switcher">
 				<button class="trigger" id="trigger">${triggerContent} <span class="caret">▾</span></button>
+				<div class="sidebar-backdrop" id="backdrop"></div>
 				<div class="sidebar" id="sidebar">
 					<button class="collapse-btn" id="collapse" title="Close sidebar">‹</button>
 					${this.#renderGroupedModules(current)}
@@ -372,10 +373,12 @@ export class RStackAppSwitcher extends HTMLElement {
 		const trigger = this.#shadow.getElementById("trigger")!;
 		const sidebar = this.#shadow.getElementById("sidebar")!;
 		const collapse = this.#shadow.getElementById("collapse")!;
+		const backdrop = this.#shadow.getElementById("backdrop")!;
 
 		// Sync sidebar DOM with tracked state (survives re-renders)
 		if (this.#isOpen) {
 			sidebar.classList.add("open");
+			backdrop.classList.add("visible");
 			document.body.classList.add("rstack-sidebar-open");
 		} else {
 			document.body.classList.remove("rstack-sidebar-open");
@@ -384,11 +387,13 @@ export class RStackAppSwitcher extends HTMLElement {
 		const open = () => {
 			this.#isOpen = true;
 			sidebar.classList.add("open");
+			backdrop.classList.add("visible");
 			document.body.classList.add("rstack-sidebar-open");
 		};
 		const close = () => {
 			this.#isOpen = false;
 			sidebar.classList.remove("open");
+			backdrop.classList.remove("visible");
 			document.body.classList.remove("rstack-sidebar-open");
 		};
 		const toggle = () => {
@@ -401,6 +406,7 @@ export class RStackAppSwitcher extends HTMLElement {
 		});
 
 		collapse.addEventListener("click", () => close());
+		backdrop.addEventListener("click", () => close());
 
 		// Close sidebar when clicking outside (on main content)
 		if (this.#outsideClickHandler) {
@@ -603,6 +609,16 @@ const STYLES = `
 
 .caret { font-size: 0.7em; opacity: 0.6; }
 
+/* ── Sidebar backdrop (mobile) ── */
+.sidebar-backdrop {
+  display: none; position: fixed; inset: 0; z-index: 10000;
+  background: rgba(0,0,0,0.4); opacity: 0; transition: opacity 0.25s ease;
+  -webkit-tap-highlight-color: transparent;
+}
+@media (max-width: 640px) {
+  .sidebar-backdrop.visible { display: block; opacity: 1; }
+}
+
 /* ── Sidebar panel ── */
 .sidebar {
   position: fixed;
@@ -636,7 +652,7 @@ const STYLES = `
   transition: background 0.15s, color 0.15s;
   z-index: 1;
 }
-.collapse-btn:hover {
+.collapse-btn:hover, .collapse-btn:active {
   background: var(--rs-bg-hover);
   color: var(--rs-text-primary);
 }
@@ -648,7 +664,7 @@ a.rstack-header {
   text-decoration: none; color: inherit; cursor: pointer;
   transition: background 0.12s;
 }
-a.rstack-header:hover { background: var(--rs-bg-hover); }
+a.rstack-header:hover, a.rstack-header:active { background: var(--rs-bg-hover); }
 .rstack-badge {
   display: flex; align-items: center; justify-content: center;
   width: 28px; height: 28px; border-radius: 8px;
diff --git a/shared/components/rstack-identity.ts b/shared/components/rstack-identity.ts
index 025b5a3..c9c4808 100644
--- a/shared/components/rstack-identity.ts
+++ b/shared/components/rstack-identity.ts
@@ -467,7 +467,7 @@ export class RStackIdentity extends HTMLElement {
 					.eid-device-nudge {
 						position: fixed; bottom: 1.5rem; right: 1.5rem; z-index: 9999;
 						background: var(--rs-bg-surface, #1e1e2e); border: 1px solid rgba(6,182,212,0.4);
-						border-radius: 14px; padding: 1rem 1.25rem; max-width: 340px;
+						border-radius: 14px; padding: 1rem 1.25rem; max-width: min(340px, calc(100vw - 3rem));
 						box-shadow: 0 8px 32px rgba(0,0,0,0.4); animation: eid-nudge-in 0.4s ease-out;
 						color: var(--rs-text-primary, #e2e8f0); font-family: system-ui, sans-serif;
 					}
@@ -2307,7 +2307,7 @@ const STYLES = `
 .dropdown {
   position: absolute; top: 100%; right: 0; margin-top: 8px;
   min-width: 200px; border-radius: 10px; overflow: hidden;
-  box-shadow: 0 8px 30px rgba(0,0,0,0.2); display: none; z-index: 100;
+  box-shadow: 0 8px 30px rgba(0,0,0,0.2); display: none; z-index: 10002;
 }
 .dropdown.open { display: block; }
 .dropdown.open { display: block; background: var(--rs-bg-surface); border: 1px solid var(--rs-border); }
@@ -2475,9 +2475,11 @@ const MODAL_STYLES = `
 .auth-modal {
   background: var(--rs-bg-surface); border: 1px solid var(--rs-border);
   border-radius: 16px; padding: 2rem; max-width: 420px; width: 90%;
+  max-height: 90dvh; overflow-y: auto;
   text-align: center; color: var(--rs-text-primary); box-shadow: var(--rs-shadow-lg);
   animation: slideUp 0.3s;
 }
+@media (max-width: 480px) { .auth-modal { padding: 1.25rem; } }
 .auth-modal h2 {
   font-size: 1.5rem; margin-bottom: 0.5rem;
   background: linear-gradient(135deg, #06b6d4, #7c3aed);
@@ -2518,7 +2520,7 @@ const MODAL_STYLES = `
   cursor: pointer; line-height: 1; padding: 4px 8px; border-radius: 6px;
   transition: all 0.15s;
 }
-.close-btn:hover { color: var(--rs-text-primary); background: var(--rs-bg-hover); }
+.close-btn:hover, .close-btn:active { color: var(--rs-text-primary); background: var(--rs-bg-hover); }
 .auth-modal { position: relative; }
 .actions--stack { flex-direction: column; }
 .btn--outline {
diff --git a/shared/components/rstack-space-switcher.ts b/shared/components/rstack-space-switcher.ts
index 91850b9..e1809ea 100644
--- a/shared/components/rstack-space-switcher.ts
+++ b/shared/components/rstack-space-switcher.ts
@@ -108,7 +108,7 @@ export class RStackSpaceSwitcher extends HTMLElement {
 			if (isOpen) {
 				const rect = trigger.getBoundingClientRect();
 				menu.style.top = `${rect.bottom + 6}px`;
-				menu.style.left = `${Math.max(4, rect.left)}px`;
+				menu.style.left = `${Math.max(4, Math.min(window.innerWidth - 268, rect.left))}px`;
 				if (!this.#loaded) {
 					await this.#loadSpaces();
 					this.#renderMenu(menu, current);
@@ -1813,7 +1813,7 @@ const STYLES = `
 
 .menu {
   position: fixed; margin-top: 0;
-  min-width: 260px; max-height: 400px; overflow-y: auto;
+  min-width: 260px; max-width: calc(100vw - 8px); max-height: 400px; overflow-y: auto;
   border-radius: 12px; box-shadow: var(--rs-shadow-lg);
   display: none; z-index: 10001;
   background: var(--rs-bg-surface); border: 1px solid var(--rs-border);
@@ -1979,9 +1979,11 @@ const REQUEST_MODAL_STYLES = `
 .auth-modal {
   background: var(--rs-bg-surface); border: 1px solid var(--rs-border);
   border-radius: 16px; padding: 2rem; max-width: 420px; width: 90%;
+  max-height: 90dvh; overflow-y: auto;
   text-align: center; color: var(--rs-text-primary); box-shadow: var(--rs-shadow-lg);
   animation: slideUp 0.3s; position: relative;
 }
+@media (max-width: 480px) { .auth-modal { padding: 1.25rem; } }
 .auth-modal h2 {
   font-size: 1.5rem; margin-bottom: 0.5rem;
   background: linear-gradient(135deg, #06b6d4, #7c3aed);
@@ -2012,7 +2014,7 @@ const REQUEST_MODAL_STYLES = `
   background: none; border: none; color: var(--rs-text-muted); font-size: 1.5rem;
   cursor: pointer; line-height: 1; padding: 4px 8px; border-radius: 6px;
 }
-.close-btn:hover { color: var(--rs-text-primary); background: var(--rs-border); }
+.close-btn:hover, .close-btn:active { color: var(--rs-text-primary); background: var(--rs-border); }
 .spinner {
   display: inline-block; width: 18px; height: 18px;
   border: 2px solid transparent; border-top-color: currentColor;
@@ -2033,9 +2035,11 @@ const EDIT_SPACE_MODAL_STYLES = `
 .edit-modal {
   background: var(--rs-bg-surface); border: 1px solid var(--rs-border);
   border-radius: 16px; padding: 2rem; max-width: 520px; width: 92%;
+  max-height: 90dvh; overflow-y: auto;
   color: var(--rs-text-primary); box-shadow: var(--rs-shadow-lg);
   animation: slideUp 0.3s; position: relative;
 }
+@media (max-width: 480px) { .edit-modal { padding: 1.25rem; } }
 .edit-modal h2 {
   font-size: 1.5rem; margin: 0 0 1rem;
   background: linear-gradient(135deg, #06b6d4, #7c3aed);
@@ -2046,17 +2050,19 @@ const EDIT_SPACE_MODAL_STYLES = `
   background: none; border: none; color: var(--rs-text-muted); font-size: 1.5rem;
   cursor: pointer; line-height: 1; padding: 4px 8px; border-radius: 6px;
 }
-.close-btn:hover { color: var(--rs-text-primary); background: var(--rs-border); }
+.close-btn:hover, .close-btn:active { color: var(--rs-text-primary); background: var(--rs-border); }
 
 /* Tabs */
-.tabs { display: flex; gap: 4px; margin-bottom: 1.2rem; border-bottom: 1px solid var(--rs-border); padding-bottom: 0; }
+.tabs { display: flex; gap: 4px; margin-bottom: 1.2rem; border-bottom: 1px solid var(--rs-border); padding-bottom: 0; overflow-x: auto; -webkit-overflow-scrolling: touch; scrollbar-width: none; }
+.tabs::-webkit-scrollbar { display: none; }
 .tab {
   padding: 8px 16px; border: none; background: none; color: var(--rs-text-secondary);
   font-size: 0.85rem; font-weight: 600; cursor: pointer; border-bottom: 2px solid transparent;
-  transition: all 0.15s; border-radius: 6px 6px 0 0;
+  transition: all 0.15s; border-radius: 6px 6px 0 0; white-space: nowrap; flex-shrink: 0;
 }
-.tab:hover { color: var(--rs-text-primary); background: var(--rs-bg-hover); }
+.tab:hover, .tab:active { color: var(--rs-text-primary); background: var(--rs-bg-hover); }
 .tab.active { color: #06b6d4; border-bottom-color: #06b6d4; }
+@media (max-width: 480px) { .tab { padding: 8px 12px; font-size: 0.8rem; } }
 
 .tab-panel { }
 .tab-panel.hidden { display: none; }