A long value list (64 timezones). On a settings route Steam's menu becomes the settings list page (p2_settings_timezone); this slab is the form a list of 15 or more takes on every other route, and the list page's fallback here. One scrolling column of two-line rows (100 px), Steam's scroller inside a 560 × 520 slab with 24 px fades; a ≤ 8 px position rail shows only while it scrolls.

Placement. It fits neither below nor above its capsule inside the modal box (y 108–628), so it goes over it, right-aligned to it. The source is white while open (covered here). Steam opens on the current value: check + focus.

Depth. T1: in-page thick glass on the window plane. Native: a non-interactive crop at +10 mm over a thick slab, rising 0 → +10 with the materialize; the laser still clicks Steam's own rows (PLAN §1.7).