html,body,#root{height:100%;margin:0}body{font-family:ui-sans-serif,system-ui,-apple-system,Segoe UI,Roboto,Helvetica,Arial}.app{display:flex;flex-direction:column;height:100%}.content{position:relative;flex:1}.fullscreen .content{position:fixed;top:0;right:0;bottom:0;left:0;background:#000;z-index:9999}.header{position:sticky;top:0;z-index:10;padding:10px 14px;border-bottom:1px solid #eee;display:flex;gap:10px;align-items:center;background:#ffffffd9;-webkit-backdrop-filter:blur(6px);backdrop-filter:blur(6px)}.app.fullscreen .header{display:none}.app.collapsed .header{transform:translateY(-100%);transition:transform .18s ease}.overlay-hint{position:fixed;top:10px;left:50%;transform:translate(-50%);background:#0009;color:#fff;padding:6px 10px;border-radius:999px;font-size:12px;cursor:pointer;z-index:20;-webkit-user-select:none;user-select:none}button{padding:8px 12px;border:1px solid #ddd;background:#fff;cursor:pointer;border-radius:8px}button.primary{background:#111;color:#fff;border-color:#111}.spacer{flex:1}