:root{--color-border-dark:#222;--color-border-light:#D1D5DB;--color-bg-white:#fff;--color-bg-option:#fff;--color-text-primary:#143B59;--color-text-correct:#155724;--color-bg-correct:#d4edda;--color-border-correct:#28a745;--color-text-incorrect:#721c24;--color-bg-incorrect:#f8d7da;--color-border-incorrect:#dc3545;--color-btn-bg:#fff;--color-btn-border:#D1D5DB;--color-btn-secondary-bg:#f2f2f2;--color-msg-correct:green;--color-msg-incorrect:red}.question-card{border:1px solid var(--color-border-dark);border-radius:6px;margin:16px 0;background:var(--color-bg-white);max-width:1380px;box-shadow:0 2px 8px #eee;padding:20px;font-size:16px}.question-header{display:flex;align-items:center;justify-content:space-between;font-size:1.2em;color:var(--color-text-primary);margin-bottom:10px;border-bottom:1px solid #143B59}.question-body p{margin-bottom:16px;font-size:16px}.options-row{display:flex;gap:16px;margin-bottom:8px;flex-wrap:wrap}.option{display:flex;align-items:center;background:var(--color-bg-option);border:1px solid var(--color-border-light);border-radius:5px;padding:8px 12px 8px 44px;width:44%;position:relative;font-weight:normal;cursor:pointer;user-select:none;transition:background-color 0.3s ease,border-color 0.3s ease,color 0.3s ease;white-space:normal;overflow-wrap:break-word;min-width:0;line-height:1.5;min-height:40px;box-sizing:border-box;font-size:16px}.option .mjx-math,.option .katex,.option [class*="math"]{font-size:16px!important;line-height:inherit!important}.option[style*="pointer-events: none"]{cursor:not-allowed!important}.option-label{position:absolute;left:0;top:0;height:100%;width:32px;background:var(--color-border-light);color:var(--color-text-primary);font-weight:bold;text-align:center;border-radius:5px 0 0 5px;display:flex;align-items:center;justify-content:center;pointer-events:none;user-select:none}.tick{display:none;position:absolute;right:8px;top:50%;transform:translateY(-50%);font-size:18px;color:green}.option.correct{background-color:var(--color-bg-correct);border-color:var(--color-border-correct);color:var(--color-text-correct)}.option.correct .tick{display:inline}.option.incorrect{animation:shake 0.4s;background-color:var(--color-bg-incorrect);border-color:var(--color-border-incorrect);color:var(--color-text-incorrect)}.solution-toggle button{color:var(--color-text-primary);margin-top:12px;background:var(--color-btn-bg);border:1px solid var(--color-btn-border);border-radius:4px;padding:7px 18px;cursor:pointer;font-weight:bold;transition:none!important}.solution-toggle button:hover,.solution-toggle button:focus,.solution-toggle button:active{background:var(--color-btn-bg)!important;color:var(--color-text-primary)!important;border-color:var(--color-btn-border)!important;box-shadow:none!important;cursor:pointer}.solution-content{border-top:1px solid var(--color-border-light);padding-top:7px;transition:none!important;display:none;margin-top:8px}.reset-btn{color:var(--color-text-primary);background:var(--color-btn-secondary-bg);border-radius:4px;padding:7px 18px;cursor:pointer;font-weight:bold;transition:none!important;font-size:.9em;display:none;margin-left:auto}.reset-btn:hover,.reset-btn:focus,.reset-btn:active{background:var(--color-btn-secondary-bg)!important;color:var(--color-text-primary)!important;border-color:#aeb7c6!important;box-shadow:none!important;cursor:pointer}.answer-message{font-weight:bold;margin-top:12px;display:none}@keyframes shake{0%{transform:translateX(0)}20%{transform:translateX(-6px)}40%{transform:translateX(6px)}60%{transform:translateX(-6px)}80%{transform:translateX(6px)}100%{transform:translateX(0)}}@media (max-width:600px){.options-row{flex-direction:column}.option{display:flex;align-items:center;width:100%;min-height:40px}}