.question-nav{max-width:var(--container-width);margin:1.5rem auto;padding:0 1.5rem;display:flex;justify-content:space-between;gap:1rem}.question-nav a{flex:1;text-align:center;padding:12px 16px;border-radius:14px;font-weight:700;text-decoration:none;background:var(--bg-card);color:var(--primary);border:2px solid var(--primary);transition:all .25s ease;animation:fadeInUpBtn .6s ease-out}.question-nav a:hover{background:var(--primary);color:#fff}.question-nav a.disabled{opacity:.4;pointer-events:none}@keyframes fadeInUpBtn{from{opacity:0;transform:translateY(15px)}to{opacity:1;transform:translateY(0)}}@media (max-width:768px){.question-nav.bottom{position:fixed;bottom:0;left:0;width:100%;background:var(--bg-card);padding:12px 1rem;border-top:1px solid var(--border-light);z-index:1000;box-shadow:0 -4px 20px rgba(0,0,0,.08);margin:0}}