:root { --bg:#0d1117; --fg:#e6edf3; --muted:#9aa4ad; --accent:#2f81f7; --surface:#111823; --border:#1f2732; }
    * { box-sizing: border-box; }
    html,body { height: 100%; margin: 0; background: var(--bg); color: var(--fg);
      font-family: system-ui,-apple-system,Segoe UI,Roboto,Helvetica,Arial,sans-serif; }

    /* App Bar */
    .appbar {
      position: fixed; inset: 0 0 auto 0; height: 56px;
      display: flex; align-items: center; justify-content: space-between;
      padding: max(.5rem, env(safe-area-inset-top)) .75rem .5rem .75rem;
      background: rgba(13,17,23,.9); backdrop-filter: blur(6px);
      border-bottom: 1px solid var(--border); z-index: 10;
    }
    .brand { display:flex; align-items:center; gap:.5rem; font-weight:700; }
    .brand svg { width: 22px; height: 22px; }
    .actions { display:flex; align-items:center; gap:.25rem; }
    .icon-btn {
      appearance:none; border:1px solid transparent; background:transparent; color:var(--fg);
      width:40px; height:40px; border-radius:10px; display:grid; place-items:center;
    }
    .icon-btn:active { background:#161b22; border-color:#2a333f; }
    .menu {
      position: relative;
    }
    .menu-panel {
      position:absolute; right:0; top:48px; min-width:160px; background:var(--surface);
      border:1px solid var(--border); border-radius:12px; padding:.25rem; display:none;
      box-shadow: 0 8px 24px rgba(0,0,0,.3);
    }
    .menu.open .menu-panel { display:block; }
    .menu-item { width:100%; text-align:left; padding:.6rem .75rem; color:var(--fg);
      background:transparent; border:0; border-radius:8px; }
    .menu-item:hover { background:#0b1320; }

    main { min-height: 100%; display: flex; flex-direction: column; align-items: center;
      justify-content: center; gap: 1rem; padding: calc(56px + 1rem) 1rem 1rem; }
    .card { width: 100%; max-width: 480px; background: var(--surface); border: 1px solid var(--border);
      border-radius: 16px; padding: 1rem; }

    /* >>> Responsive gauge sizing <<< */
    .canvas-wrap {
      /* shrink to fit small phones, but stay crisp on larger screens */
      width: min(86vw, 340px);
      /* keep square ratio */
      aspect-ratio: 1 / 1;
      display: grid; place-items: center; margin: 0 auto;
    }
    canvas { width: 100% !important; height: auto !important; display:block; }

    .readout { text-align: center; margin-top: .5rem; }
    .speed { font-size: clamp(1.8rem, 7vw, 3rem); font-weight: 800; letter-spacing: .5px; }
    .unit { font-size: .95rem; color: var(--muted); }
    .chips { display: flex; gap: .5rem; justify-content: center; flex-wrap: wrap; margin-top: .5rem; }
    .chip { padding: .35rem .6rem; border-radius: 999px; background: #0b1320; border: 1px solid var(--border); color: var(--muted); font-size: .85rem; }
    .controls { display: flex; gap: .5rem; justify-content: center; margin-top: .75rem; flex-wrap: wrap; }
    button { appearance: none; border: 1px solid #2a333f; background: #161b22; color: var(--fg); padding: .6rem .9rem; border-radius: 10px; font-weight: 600; }
    button.primary { background: var(--accent); border-color: #2563eb; color: white; }
    .status { text-align:center; font-size:.9rem; color: var(--muted); min-height: 1.2em; }
    .location { text-align: center; font-size: 1rem; margin-top: .25rem; }
    .small { font-size: .85rem; color: var(--muted); }
    footer { text-align: center; color: var(--muted); font-size: .85rem; padding-bottom: .5rem; }