*{box-sizing:border-box}
body{margin:0;font-family:system-ui,-apple-system,Segoe UI,Roboto,sans-serif;background:#f8f8f8}
header{padding:16px 20px;background:#fff;border-bottom:1px solid #e5e7eb;display:flex;align-items:center;justify-content:space-between;gap:12px;flex-wrap:wrap}
header .actions{display:flex;gap:8px}
main{display:flex;height:calc(100vh - 62px)}
.passage-box{width:50%;overflow-y:auto;padding:20px;background:#fff;border-right:1px solid #e5e7eb;position:sticky;top:0;height:100%;white-space:pre-wrap}
.questions-col{width:50%;overflow-y:auto;padding:20px}
.block{background:#fff;border:1px solid #e5e7eb;border-radius:10px;padding:14px;margin:12px 0}
.block h3{margin:0 0 6px}
.block .inst{color:#374151;font-style:italic;margin:6px 0 10px}
.q{background:#fff;border:1px solid #e5e7eb;border-radius:8px;padding:12px;margin:12px 0}
.q h4{margin:0 0 6px}
.choice{display:block;margin:4px 0}
.btn{padding:7px 10px;border:1px solid #d1d5db;background:#f3f4f6;border-radius:8px;cursor:pointer}
.btn:hover{background:#e5e7eb}
.feedback{font-weight:600;margin-top:6px}
.reveal{font-style:italic;margin-top:6px;display:none}
.menu{display:flex;gap:10px;justify-content:center;margin-top:40px}
.menu a{display:inline-block;padding:14px 22px;background:#fff;border:1px solid #d1d5db;border-radius:10px;text-decoration:none;font-size:18px;color:#111}
.small{font-size:13px;color:#6b7280}
.separator{height:10px}