Mobile UX: fixed bottom nav, compact header, less cramped cards

- App-shell layout (height:100dvh, only main scrolls) so the bottom nav
  is a natural flex child and never disappears regardless of browser
  chrome show/hide behaviour
- Bottom nav reduced from h-16 to h-14, icons from 20px to 18px, labels
  from 10px to 9px — slimmer bar, still readable
- Header: min-w-0 on search prevents horizontal overflow; user/sign-out
  hidden on mobile (accessible via Settings); logo shortened to "YT" on
  mobile; px-3 / h-12 on mobile instead of px-4 / h-14
- Grid card descriptions hidden on mobile (hidden sm:block) — reduces
  height cramping in the 2-column feed
- scrollToTop() utility replaces window.scrollTo so pagination still
  scrolls to top within the new scroll container

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

frontend/src/components/Layout.jsx

@@ -30,17 +30,17 @@ function BottomNav({ newCount }) {
 
   return (
     <nav
-      className="sm:hidden fixed bottom-0 inset-x-0 z-50 bg-zinc-950/98 backdrop-blur border-t border-zinc-800"
+      className="sm:hidden shrink-0 bg-zinc-950/98 backdrop-blur border-t border-zinc-800"
       style={{ paddingBottom: "env(safe-area-inset-bottom)" }}
     >
-      <div className="flex items-stretch h-16">
+      <div className="flex items-stretch h-14">
         {tabs.map((tab) => (
           <NavLink
             key={tab.to}
             to={tab.to}
             end={tab.end}
             className={({ isActive }) =>
-              `relative flex-1 flex flex-col items-center justify-center gap-1 transition-colors ${
+              `relative flex-1 flex flex-col items-center justify-center gap-0.5 transition-colors ${
                 isActive ? "text-accent" : "text-zinc-500"
               }`
             }
@@ -51,16 +51,16 @@ function BottomNav({ newCount }) {
                   {isActive && (
                     <span className="absolute -inset-2 rounded-xl bg-accent/10" />
                   )}
-                  <svg className="w-5 h-5 relative" fill="none" stroke="currentColor" viewBox="0 0 24 24">
+                  <svg className="w-[18px] h-[18px] relative" fill="none" stroke="currentColor" viewBox="0 0 24 24">
                     {tab.icon}
                   </svg>
                   {tab.badge > 0 && (
-                    <span className="absolute -top-1 -right-1.5 min-w-[14px] h-3.5 bg-accent text-black text-[9px] font-bold rounded-full flex items-center justify-center px-0.5 leading-none">
+                    <span className="absolute -top-1 -right-1.5 min-w-[13px] h-3 bg-accent text-black text-[8px] font-bold rounded-full flex items-center justify-center px-0.5 leading-none">
                       {tab.badge > 99 ? "99+" : tab.badge}
                     </span>
                   )}
                 </div>
-                <span className={`text-[10px] font-medium leading-none ${isActive ? "font-semibold" : ""}`}>
+                <span className="text-[9px] font-medium leading-none">
                   {tab.label}
                 </span>
               </>
@@ -95,16 +95,16 @@ function DownloadIndicator() {
   return (
     <Link
       to="/downloads"
-      className="flex items-center gap-2 px-2.5 py-1 rounded-lg bg-zinc-800 hover:bg-zinc-700 transition-colors text-xs text-zinc-300 shrink-0"
+      className="flex items-center gap-1.5 px-2 py-1 rounded-lg bg-zinc-800 hover:bg-zinc-700 transition-colors text-xs text-zinc-300 shrink-0"
       title={`${active.length} download${active.length > 1 ? "s" : ""} in progress`}
     >
-      <svg className="w-3.5 h-3.5 animate-spin text-accent" fill="none" viewBox="0 0 24 24">
+      <svg className="w-3 h-3 animate-spin text-accent shrink-0" fill="none" viewBox="0 0 24 24">
         <circle className="opacity-20" cx="12" cy="12" r="10" stroke="currentColor" strokeWidth="3" />
         <path className="opacity-80" fill="currentColor" d="M4 12a8 8 0 018-8v4a4 4 0 00-4 4H4z" />
       </svg>
-      <span className="font-mono tabular-nums">{pct.toFixed(0)}%</span>
+      <span className="font-mono tabular-nums text-[11px]">{pct.toFixed(0)}%</span>
       {active.length > 1 && (
-        <span className="text-zinc-500">+{active.length - 1}</span>
+        <span className="hidden sm:inline text-zinc-500">+{active.length - 1}</span>
       )}
     </Link>
   );
@@ -207,27 +207,27 @@ export default function Layout() {
   const newCount = useNewVideosCount();
 
   return (
-    <div className="min-h-screen flex flex-col">
+    <div className="flex flex-col overflow-hidden" style={{ height: "100dvh" }}>
       {/* Header */}
-      <header className="sticky top-0 z-40 bg-zinc-950/90 backdrop-blur border-b border-zinc-800">
-        <div className="max-w-screen-xl mx-auto px-4 h-14 flex items-center gap-4">
+      <header className="shrink-0 z-40 bg-zinc-950/90 backdrop-blur border-b border-zinc-800">
+        <div className="max-w-screen-xl mx-auto px-3 h-12 sm:h-14 flex items-center gap-2 sm:gap-4">
           {/* Logo */}
           <button
             onClick={() => navigate("/")}
-            className="font-display font-bold text-lg text-accent shrink-0"
+            className="font-display font-bold text-base sm:text-lg text-accent shrink-0"
           >
-            YT Hub
+            YT
           </button>
 
-          {/* Search */}
-          <div className="flex-1 max-w-2xl">
+          {/* Search — min-w-0 prevents it from overflowing on narrow screens */}
+          <div className="flex-1 min-w-0">
             <SearchBar />
           </div>
 
           {/* Active downloads indicator */}
           <DownloadIndicator />
 
-          {/* Nav */}
+          {/* Desktop nav */}
           <nav className="hidden sm:flex items-center gap-0.5">
             <NavItem to="/">Home</NavItem>
 
@@ -258,21 +258,27 @@ export default function Layout() {
             <NavItem to="/settings">Settings</NavItem>
           </nav>
 
-          {/* User */}
+          {/* User — hidden on mobile, sign out is in Settings */}
           <button
             onClick={logout}
-            className="ml-2 text-xs text-zinc-500 hover:text-zinc-300 transition-colors shrink-0"
+            className="hidden sm:inline-flex ml-2 text-xs text-zinc-500 hover:text-zinc-300 transition-colors shrink-0"
           >
             {user?.username} · sign out
           </button>
         </div>
       </header>
 
-      {/* Page content */}
-      <main className="flex-1 max-w-screen-xl mx-auto w-full px-4 py-6 pb-28 sm:pb-6" style={{ paddingBottom: "calc(7rem + env(safe-area-inset-bottom, 0px))" }}>
+      {/* Page content — only this area scrolls */}
+      <main
+        data-scroll
+        className="flex-1 min-h-0 overflow-y-auto overscroll-contain"
+      >
+        <div className="max-w-screen-xl mx-auto w-full px-3 sm:px-4 py-4 sm:py-6">
           <Outlet />
+        </div>
       </main>
 
+      {/* Bottom nav — natural flex child, always visible on mobile */}
       <BottomNav newCount={newCount} />
     </div>
   );

frontend/src/components/VideoCard.jsx

@@ -378,7 +378,7 @@ export default function VideoCard({ video, size = "md", onDismiss, variant = "gr
           </div>
 
           {video.description && (
-            <p className="text-[11px] leading-relaxed text-zinc-500 line-clamp-2 mt-0.5">
+            <p className="hidden sm:block text-[11px] leading-relaxed text-zinc-500 line-clamp-2 mt-0.5">
               {video.description.replace(/\n+/g, " ")}
             </p>
           )}

frontend/src/pages/Discovery.jsx

@@ -6,6 +6,7 @@ import {
   followDiscovery, dismissDiscovery, dismissDiscoveryVideo, refreshDiscovery,
 } from "../api";
 import VideoCard from "../components/VideoCard";
+import { scrollToTop } from "../utils/scroll";
 
 const PAGE_SIZE = 50;
 
@@ -305,7 +306,7 @@ export default function DiscoveryPage() {
           </div>
           <div className="flex items-center justify-center gap-3 pt-2">
             <button
-              onClick={() => { setChannelPage(p => p - 1); window.scrollTo({ top: 0, behavior: "smooth" }); }}
+              onClick={() => { setChannelPage(p => p - 1); scrollToTop(); }}
               disabled={channelPage === 0}
               className="px-4 py-2 rounded-lg bg-zinc-800 text-zinc-300 text-sm font-medium hover:bg-zinc-700 disabled:opacity-30 disabled:cursor-not-allowed transition-colors"
             >
@@ -313,7 +314,7 @@ export default function DiscoveryPage() {
             </button>
             <span className="text-zinc-500 text-sm tabular-nums">Page {channelPage + 1}</span>
             <button
-              onClick={() => { setChannelPage(p => p + 1); window.scrollTo({ top: 0, behavior: "smooth" }); }}
+              onClick={() => { setChannelPage(p => p + 1); scrollToTop(); }}
               disabled={!hasNextChannelPage}
               className="px-4 py-2 rounded-lg bg-zinc-800 text-zinc-300 text-sm font-medium hover:bg-zinc-700 disabled:opacity-30 disabled:cursor-not-allowed transition-colors"
             >
@@ -334,7 +335,7 @@ export default function DiscoveryPage() {
           </div>
           <div className="flex items-center justify-center gap-3 pt-2">
             <button
-              onClick={() => { setVideoPage(p => p - 1); window.scrollTo({ top: 0, behavior: "smooth" }); }}
+              onClick={() => { setVideoPage(p => p - 1); scrollToTop(); }}
               disabled={videoPage === 0}
               className="px-4 py-2 rounded-lg bg-zinc-800 text-zinc-300 text-sm font-medium hover:bg-zinc-700 disabled:opacity-30 disabled:cursor-not-allowed transition-colors"
             >
@@ -342,7 +343,7 @@ export default function DiscoveryPage() {
             </button>
             <span className="text-zinc-500 text-sm tabular-nums">Page {videoPage + 1}</span>
             <button
-              onClick={() => { setVideoPage(p => p + 1); window.scrollTo({ top: 0, behavior: "smooth" }); }}
+              onClick={() => { setVideoPage(p => p + 1); scrollToTop(); }}
               disabled={!hasNextVideoPage}
               className="px-4 py-2 rounded-lg bg-zinc-800 text-zinc-300 text-sm font-medium hover:bg-zinc-700 disabled:opacity-30 disabled:cursor-not-allowed transition-colors"
             >

frontend/src/pages/History.jsx

@@ -2,6 +2,7 @@ import { useState } from "react";
 import { useQuery } from "@tanstack/react-query";
 import { getHistory } from "../api";
 import VideoCard from "../components/VideoCard";
+import { scrollToTop } from "../utils/scroll";
 
 const PAGE_SIZE = 25;
 
@@ -40,7 +41,7 @@ export default function History() {
           </div>
           <div className="flex items-center justify-center gap-3 pt-2">
             <button
-              onClick={() => { setPage(p => p - 1); window.scrollTo({ top: 0, behavior: "smooth" }); }}
+              onClick={() => { setPage(p => p - 1); scrollToTop(); }}
               disabled={page === 0}
               className="px-4 py-2 rounded-lg bg-zinc-800 text-zinc-300 text-sm font-medium hover:bg-zinc-700 disabled:opacity-30 disabled:cursor-not-allowed transition-colors"
             >
@@ -48,7 +49,7 @@ export default function History() {
             </button>
             <span className="text-zinc-500 text-sm tabular-nums">Page {page + 1}</span>
             <button
-              onClick={() => { setPage(p => p + 1); window.scrollTo({ top: 0, behavior: "smooth" }); }}
+              onClick={() => { setPage(p => p + 1); scrollToTop(); }}
               disabled={!hasNext}
               className="px-4 py-2 rounded-lg bg-zinc-800 text-zinc-300 text-sm font-medium hover:bg-zinc-700 disabled:opacity-30 disabled:cursor-not-allowed transition-colors"
             >

frontend/src/pages/Home.jsx

@@ -2,6 +2,7 @@ import { useState, useMemo } from "react";
 import { useQuery, useMutation, useQueryClient } from "@tanstack/react-query";
 import { homeFeed, surpriseMe, getSettings, updateSettings, getChannels, markChannelsSeen } from "../api";
 import VideoCard from "../components/VideoCard";
+import { scrollToTop } from "../utils/scroll";
 
 const PAGE_SIZE = 25;
 
@@ -95,7 +96,7 @@ export default function Home() {
     setShuffleKey(k => k + 1);
     setPage(0);
     setDismissed(new Set());
-    window.scrollTo({ top: 0, behavior: "smooth" });
+    scrollToTop();
   };
 
   return (
@@ -235,7 +236,7 @@ export default function Home() {
           )}
           <div className="flex items-center justify-center gap-3 pt-2">
             <button
-              onClick={() => { setPage(p => p - 1); window.scrollTo({ top: 0, behavior: "smooth" }); }}
+              onClick={() => { setPage(p => p - 1); scrollToTop(); }}
               disabled={page === 0}
               className="px-4 py-2 rounded-lg bg-zinc-800 text-zinc-300 text-sm font-medium hover:bg-zinc-700 disabled:opacity-30 disabled:cursor-not-allowed transition-colors"
             >
@@ -243,7 +244,7 @@ export default function Home() {
             </button>
             <span className="text-zinc-500 text-sm tabular-nums">Page {page + 1}</span>
             <button
-              onClick={() => { setPage(p => p + 1); window.scrollTo({ top: 0, behavior: "smooth" }); }}
+              onClick={() => { setPage(p => p + 1); scrollToTop(); }}
               disabled={!hasNextPage}
               className="px-4 py-2 rounded-lg bg-zinc-800 text-zinc-300 text-sm font-medium hover:bg-zinc-700 disabled:opacity-30 disabled:cursor-not-allowed transition-colors"
             >

frontend/src/utils/scroll.js

@@ -0,0 +1,5 @@
+export function scrollToTop(behavior = "smooth") {
+  const main = document.querySelector("main[data-scroll]");
+  if (main) main.scrollTo({ top: 0, behavior });
+  else window.scrollTo({ top: 0, behavior });
+}