:root{--tif-navy:#0f172a;--tif-deep:#101827;--tif-blue:#2563eb;--tif-sky:#38bdf8;--tif-green:#22c55e;--tif-bg:#f6faff;--tif-soft:#eaf4ff;--tif-card:#ffffff;--tif-text:#111827;--tif-muted:#64748b;--tif-border:#dbe7f5;--tif-shadow:0 24px 60px rgba(15,23,42,.12);--tif-shadow-soft:0 14px 36px rgba(15,23,42,.08);--tif-radius:20px}*{box-sizing:border-box}html{scroll-behavior:smooth}body{margin:0;background:var(--tif-bg);color:var(--tif-text);font-family:Inter,ui-sans-serif,system-ui,-apple-system,BlinkMacSystemFont,"Segoe UI",Arial,sans-serif;line-height:1.6;font-size:16px}a{color:inherit;text-decoration:none}img{max-width:100%;height:auto;display:block}button,input,select,textarea{font:inherit}.container{width:min(1140px,calc(100% - 60px));margin-inline:auto}.container.narrow{width:min(860px,calc(100% - 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button{padding:14px}.single-mcq-card{padding:22px}}


/* Interactive MCQ answer checking — v5.3.6 */
.answer-instruction{margin:-6px 0 14px;color:var(--tif-muted);font-size:14px;font-weight:700}
.answer-options .answer-option,.mcq-card-options .mcq-card-option{width:100%;display:flex;align-items:flex-start;gap:8px;text-align:left;border:1px solid var(--tif-border);background:#f8fbff;border-radius:16px;padding:13px 14px;cursor:pointer;color:var(--tif-navy);font-weight:700;line-height:1.45;transition:border-color .18s ease,background .18s ease,color .18s ease,transform .18s ease,box-shadow .18s ease}
.answer-options .answer-option:hover,.mcq-card-options .mcq-card-option:hover{border-color:#93c5fd;background:#eff6ff;transform:translateY(-1px);box-shadow:0 8px 18px rgba(37,99,235,.08)}
.answer-options .answer-option:focus-visible,.mcq-card-options .mcq-card-option:focus-visible{outline:3px solid rgba(37,99,235,.25);outline-offset:2px}
.answer-options .answer-option b,.mcq-card-options .mcq-card-option b{flex:0 0 auto}
.answer-options .answer-option span,.mcq-card-options .mcq-card-option span{flex:1}
.answer-options .answer-option.correct,.mcq-card-options .mcq-card-option.correct{border-color:#22c55e;background:#dcfce7;color:#166534;box-shadow:0 8px 20px rgba(34,197,94,.12)}
.answer-options .answer-option.incorrect,.mcq-card-options .mcq-card-option.incorrect{border-color:#ef4444;background:#fee2e2;color:#991b1b;box-shadow:0 8px 20px rgba(239,68,68,.1)}
.answer-options .answer-option.correct::after,.mcq-card-options .mcq-card-option.correct::after{content:'✓';margin-left:auto;font-size:18px;font-weight:950;line-height:1}
.answer-options .answer-option.incorrect::after,.mcq-card-options .mcq-card-option.incorrect::after{content:'✕';margin-left:auto;font-size:17px;font-weight:950;line-height:1}
.answer-options .answer-option:disabled,.mcq-card-options .mcq-card-option:disabled{cursor:default;opacity:1;transform:none}
.compact-answer-options{display:grid;gap:8px;margin-bottom:10px}
.mcq-card-options.compact-answer-options .mcq-card-option{padding:10px 12px;border-radius:14px;font-size:14px}
.answer-feedback{min-height:0;margin:0 0 12px;font-size:14px;font-weight:900}
.answer-feedback:empty{display:none}
.answer-feedback.is-correct{color:#15803d}
.answer-feedback.is-incorrect{color:#b91c1c}
.answer-feedback.is-neutral{color:#1d4ed8}
.read-answer.inline-answer-toggle{display:inline-flex;align-items:center;justify-content:center;border:0;background:transparent;padding:6px 0;color:var(--tif-blue);font-weight:950;cursor:pointer}
.read-answer.inline-answer-toggle:disabled{color:var(--tif-muted);cursor:default}
.inline-answer-box[hidden],.answer-box[hidden]{display:none!important}
.inline-answer-box:not([hidden]){display:block;margin-top:16px;padding:18px;border:1px solid #bbf7d0;border-radius:16px;background:#f0fdf4;color:#14532d}
.inline-correct-answer{font-weight:700}
.inline-explanation{margin-top:12px;padding-top:12px;border-top:1px solid rgba(22,101,52,.18)}
.inline-explanation p,.content-explanation p{margin:6px 0 0;white-space:normal}