Higher, lower, or missing a reference?

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</style></head><body class="music"><main><header><p class="kicker">STAFF LAB / FOUR ORIGINAL ITEMS</p><h1>Higher, lower, or missing a reference?</h1><p>Compare markers on the same staff. No clef is supplied; drawing indexes are not note names.</p></header><div class="content"><div class="controls"><button type="button" id="m1">M01</button><button type="button" id="m2">M02</button><button type="button" id="m3">M03</button><button type="button" id="m4">M04</button></div><h2 id="question"></h2><div id="staff-drawing"></div><p class="facts" id="positions"></p><div class="controls"><button type="button" id="answer-a">A higher</button><button type="button" id="answer-b">B higher</button><button type="button" id="answer-same">Same height</button><button type="button" id="answer-unknown">Cannot determine</button><button type="button" id="answer-e">Letter E</button><button type="button" id="answer-g">Letter G</button></div><label for="reason">My reasoning (not automatically graded)<textarea id="reason" rows="3"></textarea></label><button type="button" id="check">Check answer</button><div class="result" id="feedback" aria-live="polite">Choose an answer, then check.</div><details id="teacher"><summary>Teacher reasoning</summary><p id="teacher-text"></p></details><section class="panel "><h2>Placement reference</h2><p>0 bottom line · 1 first space · 2 second line · 3 second space · 4 middle line. Remaining upper lines: 6 and 8. Horizontal spacing does not change vertical comparison.</p><button type="button" id="reset">Reset all attempts</button></section></div><footer><p>Original fictional teaching example. Entries are temporary and are cleared on reload; no responses are sent or saved.</p></footer></main><script>
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