:root{font-family:Inter,system-ui,sans-serif;background:#0f172a;color:#f8fafc}body{margin:0;min-height:100vh;background:linear-gradient(180deg,#111827,#0f172a)}#app{max-width:540px;margin:0 auto;padding:20px}.app-header{font-size:1.5rem;font-weight:700;margin-bottom:20px}.app-welcome,.app-text,.app-status,.app-result{margin-bottom:16px;line-height:1.6}.app-buttons{display:grid;gap:12px}.app-button,.app-back-button,.app-list-item{width:100%;border:none;border-radius:14px;padding:14px 16px;font-size:1rem;font-weight:600;cursor:pointer;background:#1f2937;color:#f8fafc;transition:transform .16s ease,background .16s ease}.app-button:hover,.app-back-button:hover,.app-list-item:hover{background:#374151;transform:translateY(-1px)}.app-back-button{margin-top:20px}.app-input{width:100%;padding:12px 14px;border-radius:12px;border:1px solid #334155;background:#111827;color:#f8fafc;margin-bottom:12px}.app-list{display:grid;gap:10px}.app-code{background:#111827;border:1px solid #334155;border-radius:12px;padding:12px;word-break:break-all}