:root{--ink: #f4f3f1;--ink-dim: rgba(244, 243, 241, .6);--ink-faint: rgba(244, 243, 241, .3);--surface: #101113;--surface-raised: #1a1c1f;--surface-line: rgba(244, 243, 241, .14);--ink-selected: #2c3138;--correct: #3f7d5c;--noted: #4b4f55;--curve: cubic-bezier(.2, 0, 0, 1);--ledge-height: 68px;--rail-height: 48px;--safe-top: env(safe-area-inset-top, 0px);--safe-bottom: env(safe-area-inset-bottom, 0px);--t-ack: 90ms;--t-crossfade: .2s;--t-fade-out: .14s;--t-geometry: .24s;--t-deck-opacity: .16s;--t-verdict: .12s;--t-marks: .12s;--t-dot: .2s;--t-notice: .16s;--t-ledge-offset: 60ms}*{box-sizing:border-box}html,body{margin:0;padding:0;height:100%;background:var(--surface);color:var(--ink);font:400 16px/1.4 -apple-system,BlinkMacSystemFont,Segoe UI,Roboto,sans-serif;overscroll-behavior:none}.shell{--covered: 0px;position:relative;height:100dvh;overflow:hidden;touch-action:manipulation}.rail{position:fixed;top:0;left:0;right:0;z-index:50;height:calc(var(--rail-height) + var(--safe-top));padding:var(--safe-top) 16px 0;display:flex;flex-direction:column;justify-content:center;gap:4px;background:linear-gradient(180deg,#101113eb,#10111300)}.rail__row{display:flex;align-items:center;justify-content:space-between;height:32px}.rail__label{font-size:13px;color:var(--ink-dim)}.wordmark{display:block;text-align:right;font-size:11px;opacity:.4}.mute{background:none;border:0;color:var(--ink-dim);font-size:12px;min-height:32px;padding:0 4px}.strip{display:flex;gap:6px;height:16px;align-items:center}.dot{width:8px;height:8px;border-radius:50%;transition:background-color var(--t-dot, .2s) var(--curve),opacity var(--t-dot, .2s) var(--curve)}.dot[data-dot=remaining]{box-shadow:inset 0 0 0 1px var(--ink-faint)}.dot[data-dot=current]{box-shadow:inset 0 0 0 2px var(--ink)}.dot[data-dot=answered]{background:var(--ink-dim)}.dot[data-dot=right]{background:var(--correct)}.dot[data-dot=noted]{background:var(--noted)}.shell[data-mode=video-compact]{--covered: calc(var(--stage-full) - var(--stage-compact))}.shell[data-mode=arrive],.shell[data-mode=plate-only]{--covered: calc(var(--deck-height) + var(--ledge-height))}.stage{position:absolute;top:calc(var(--rail-height) + var(--safe-top));left:0;right:0;height:var(--stage-full);overflow:hidden;background:var(--surface)}.stage__ground{position:absolute;top:0;right:0;bottom:0;left:0;background-size:cover;background-position:center;z-index:0}.poster,.media{position:absolute;top:0;left:0;width:100%;height:var(--stage-full);object-fit:cover;z-index:0;transition:transform var(--t-geometry, .24s) var(--curve),opacity var(--t-crossfade, .2s) var(--curve)}.media{z-index:1;transform-origin:50% 42%}.shell[data-mode=video-compact] .poster,.shell[data-mode=video-compact] .media{transform:translate3d(0,var(--lock-y),0) scale(var(--lock-k, 1))}.shell[data-mode=plate-only] .poster,.shell[data-mode=plate-only] .media,.shell[data-mode=plate-only] .stage__ground{display:none}.plate{position:absolute;top:0;right:0;bottom:0;left:0;z-index:10;padding:20px 16px;display:flex;flex-direction:column;justify-content:flex-end;gap:8px;background:var(--surface);opacity:0;pointer-events:none;transition:opacity var(--t-crossfade, .2s) var(--curve);padding-bottom:calc(var(--covered, 0px) + 20px);user-select:none;-webkit-user-select:none}.shell[data-state=Q_OPTIONS_RESTING] .plate--question,.shell[data-state=COMMIT] .plate--question,.shell[data-state=REVEAL_RIGHT] .plate--question,.shell[data-state=REVEAL_HOLD] .plate--question,.shell[data-state=HANDOFF] .plate--question,.shell[data-state=ARRIVE] .plate--recognition,.shell[data-state=LANDING] .plate--diagnosis,.shell[data-mode=plate-only] .plate{opacity:1;pointer-events:auto}.plate--recognition{background:transparent;background-image:linear-gradient(180deg,#10111300 40%,#101113db)}.plate__title{margin:0;font-size:24px;font-weight:700}.plate__line{margin:0;font-size:14px;color:var(--ink-dim)}.plate__eyebrow{margin:0;font-size:12px;color:var(--ink-dim)}.stem{margin:0;font-size:17px;line-height:1.45}.diag__misconception{margin:0;font-size:19px;font-weight:700}.diag__separator{margin:0;font-size:15px}.diag__answer{margin:0;font-size:13px;color:var(--ink-dim)}.verdict__line{margin:0;font-size:32px;font-weight:700}.verdict__sub{margin:0;font-size:14px;color:var(--ink-dim)}.pill{position:absolute;right:16px;bottom:calc(var(--covered, 0px) + 16px);z-index:20;min-height:44px;min-width:44px;padding:0 14px;border:0;border-radius:22px;background:#101113b8;color:var(--ink);font-size:13px}.player{position:absolute;left:16px;right:16px;bottom:calc(var(--covered, 0px) + 16px);z-index:20;display:flex;align-items:center;gap:12px}.player__toggle{min-height:44px;padding:0 14px;border:0;border-radius:22px;background:#101113b8;color:var(--ink);font-size:13px}.player__scrub{flex:1;accent-color:var(--ink)}.notice{position:absolute;left:16px;right:16px;bottom:calc(var(--covered, 0px) + 72px);z-index:60;padding:12px 14px;border-radius:12px;background:var(--surface-raised);animation:notice-in var(--t-notice, .16s) var(--curve)}@keyframes notice-in{0%{opacity:0}}.notice__line{margin:0 0 8px;font-size:14px}.notice__action{min-height:44px;border:0;border-radius:10px;padding:0 14px;background:var(--ink);color:var(--surface);font-size:14px}.deck{position:absolute;left:0;right:0;bottom:calc(var(--ledge-height) + var(--safe-bottom));z-index:30;padding:12px 16px;display:flex;flex-direction:column;gap:10px;background:var(--surface);height:var(--deck-height);overflow:hidden;transition:transform var(--t-geometry, .24s) var(--curve),opacity var(--t-deck-opacity, .16s) var(--curve)}.shell[data-mode=video-full] .deck{transform:translate3d(0,var(--panel-shift),0);opacity:0;pointer-events:none}.deck__stem{margin:0 0 4px;font-size:14px;max-height:66px;overflow-y:auto}.opt{display:flex;align-items:center;justify-content:space-between;gap:12px;min-height:52px;width:100%;padding:0 14px;border:1px solid var(--surface-line);border-radius:12px;background:var(--surface-raised);color:var(--ink);font-size:17px;line-height:24px;text-align:left;transition:background-color var(--t-marks, .12s) var(--curve),border-color var(--t-marks, .12s) var(--curve),opacity var(--t-marks, .12s) var(--curve),font-weight var(--t-marks, .12s) var(--curve)}.shell[data-rung=R2] .opt{font-size:16px;line-height:22px}.shell[data-rung=R1] .opt{font-size:15px;line-height:20px}.opt__glyph{flex:0 0 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.card__name{font-size:16px;font-weight:400}.card__sub{font-size:13px;color:var(--ink-dim)}.ledge{position:absolute;left:0;right:0;bottom:0;z-index:40;height:calc(var(--ledge-height) + var(--safe-bottom));padding:0 16px calc(12px + var(--safe-bottom));display:flex;align-items:center;gap:10px;background:var(--surface);transition:transform var(--t-geometry, .24s) var(--curve),opacity var(--t-crossfade, .2s) var(--curve)}.shell[data-mode=video-full] .ledge{transform:translate3d(0,calc(var(--ledge-height) + var(--safe-bottom)),0);opacity:0;pointer-events:none}.ledge[data-ledge=reserved]{pointer-events:none}.ledge__button{min-height:48px;border:0;border-radius:12px;font-size:15px;color:var(--ink);background:var(--surface-raised);animation:ledge-fill var(--t-crossfade, .2s) var(--curve)}@keyframes ledge-fill{0%{opacity:0;transform:translate3d(0,6px,0)}}.ledge[data-ledge=two-weighted] .ledge__button[data-weight=secondary]{flex:0 0 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.ledge{transform:none}}.meaning{display:flex;flex-direction:column;gap:6px}.meaning__line{margin:0;font-size:16px}.meaning__fix{margin:0;font-size:14px;color:var(--ink-dim)}.alternates{display:flex;gap:16px;align-items:center;min-height:44px}.alternate{background:none;border:0;padding:0;min-height:44px;color:var(--ink);font-size:14px;text-decoration:underline;text-underline-offset:4px}.alternate[disabled]{color:var(--ink-faint);text-decoration:none}.review{display:flex;gap:8px}.review__row{flex:1;min-height:44px;border:1px solid var(--surface-line);border-radius:10px;background:var(--surface-raised);color:var(--ink);font-size:15px}.review__row[data-correct=true]{border-color:var(--correct)}.review__row[data-correct=false]{border-color:var(--noted)}.review__index{font-weight:700}.review__label{display:none}.verdict__score{margin:0;font-size:56px;font-weight:700;line-height:1}.mastered{margin:8px 0 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14px}.field__invalid{margin:0;font-size:13px;color:var(--ink)}.field__note{margin:0;font-size:13px;color:var(--ink-dim)}.course{display:flex;flex-direction:column;gap:6px}.course__title{margin:0;font-size:19px;font-weight:700}.course__includes{margin:0;padding-left:18px;font-size:14px;color:var(--ink-dim)}.course__price,.bar,.course__status{margin:0;font-size:14px}.deck__note{margin:4px 0 0;font-size:13px;color:var(--ink-dim)}.internal{display:flex;flex-direction:column;gap:8px}.internal__note,.internal__result{margin:0;font-size:13px;color:var(--ink-dim)}.shell[data-state=DOOR] .ledge,.shell[data-state=VERIFY] .ledge,.shell[data-state=INTERNAL_LOGIN] .ledge{position:sticky}