.nn-qb-tabs{display:flex;gap:8px;background:#fff;
  padding:12px 0;margin:0 0 20px;border-bottom:1px solid #e7ebef;flex-wrap:wrap;}
.nn-qb-tab-btn{font-family:'Montserrat',sans-serif;font-size:13px;font-weight:700;
  color:#2C3E50;background:#f4f6f7;border:1px solid #e7ebef;border-radius:20px;
  padding:8px 16px;cursor:pointer;transition:all .15s ease;}
.nn-qb-tab-btn.is-active,.nn-qb-tab-btn:hover{background:#16A085;color:#fff;border-color:#16A085;}
.nn-qb-section{margin-bottom:8px;}
.nn-qb-section-title{
  font-family:'Montserrat',sans-serif;
  font-size:24px;
  font-weight:800;
  line-height:1.3;
  color:#2C3E50 !important;
  margin:12px 0 20px;
}
.nn-qb-subhead{
  display:inline-flex;
  align-items:center;
  width:auto;
  font-family:'Montserrat',sans-serif;
  font-size:11px;
  font-weight:800;
  letter-spacing:.07em;
  text-transform:uppercase;
  color:#435163;
  background:#f1f4f6;
  border:1px solid #e3e8ec;
  padding:6px 11px;
  border-radius:6px;
  margin:0 0 14px;
}
.nn-qb-subhead + .nn-qb-subhead{margin-top:0;margin-bottom:16px;}
.nn-qb-card{
  background:#fff;
  border:1px solid #e4e9ee;
  border-radius:12px;
  padding:24px 26px;
  margin:0 0 18px;
  box-shadow:0 1px 3px rgba(44,62,80,0.035);
  max-width:960px;
}
.nn-qb-card-top{
  display:flex;
  align-items:center;
  gap:9px;
  margin-bottom:12px;
}
.nn-qb-qnum{
  font-family:'Montserrat',sans-serif;
  font-size:11px;
  font-weight:800;
  color:#7a8694;
  letter-spacing:.05em;
}
.nn-qb-badge{
  font-family:'Montserrat',sans-serif;
  font-size:11px;
  font-weight:750;
  color:#087967 !important;
  background:#EAF7F4;
  border:1px solid #D7EEE8;
  padding:4px 9px;
  border-radius:6px;
}
.nn-qb-card h2,
.nn-qb-card h3,
.nn-qb-card h4,
.nn-qb-card h5,
.nn-qb-card h6{
  font-family:'Montserrat',sans-serif;
  color:#1c2b3a !important;
  font-size:17px;
  font-weight:700;
  line-height:1.65;
  margin:0 0 14px;
}
.nn-qb-card p{
  color:#2C3E50 !important;
  line-height:1.72;
  margin:8px 0;
  font-size:17px;
}
.nn-qb-card p.nn-qb-q-title{
  font-size:17px;
  font-weight:700;
  line-height:1.65;
  color:#1c2b3a !important;
  margin:0 0 14px;
}
.nn-qb-sublist{margin:10px 0 6px;}
.nn-qb-subitem{
  display:flex;
  align-items:flex-start;
  gap:12px;
  padding:13px 0;
  border-top:1px solid #edf0f2;
}
.nn-qb-subitem:first-child{border-top:none;padding-top:2px;}
.nn-qb-subletter{
  flex:0 0 24px;
  font-family:'Montserrat',sans-serif;
  font-weight:800;
  color:#16A085;
  font-size:16px;
  line-height:1.72;
}
.nn-qb-subtext{
  color:#2C3E50 !important;
  line-height:1.72;
  font-size:17px;
  flex:1;
  min-width:0;
}
.nn-qb-subtext mjx-container{
  overflow-x:auto;
  overflow-y:hidden;
  scrollbar-width:none;
}
.nn-qb-subtext mjx-container::-webkit-scrollbar{ display:none; }
@media (max-width:640px){
  .nn-qb-subtext mjx-container{ font-size:85%; }
}
@media (max-width:400px){
  .nn-qb-subtext mjx-container{ font-size:78%; }
}
.nn-qb-subsublist{margin:6px 0 4px;}
.nn-qb-subsubitem{display:flex;gap:8px;padding:4px 0;}
.nn-qb-subsubletter{
  flex:0 0 22px;
  font-family:'Montserrat',sans-serif;
  font-weight:700;
  color:#778493;
  font-size:14px;
  line-height:1.7;
}
.nn-qb-subsubtext{
  color:#2C3E50 !important;
  line-height:1.7;
  font-size:16px;
  flex:1;
  min-width:0;
}
.nn-qb-card table{width:100%;}
.nn-qb-card mjx-container{
  overflow-x:auto;
  overflow-y:hidden;
  scrollbar-width:none;
}
.nn-qb-card mjx-container::-webkit-scrollbar{ display:none; }
@media (max-width:640px){
  .nn-qb-card mjx-container{ font-size:85%; }
}
@media (max-width:400px){
  .nn-qb-card mjx-container{ font-size:78%; }
}
.nn-qb-reveal{margin-top:10px;}
.nn-qb-reveal summary{font-family:'Montserrat',sans-serif;font-size:13px;font-weight:700;
  color:#16A085;cursor:pointer;list-style:none;display:inline-flex;align-items:center;
  gap:6px;padding:8px 16px;border:1px solid #16A085;border-radius:20px;width:fit-content;}
.nn-qb-reveal summary::-webkit-details-marker{display:none;}
.nn-qb-reveal[open] summary{background:#16A085;color:#fff;}
.nn-qb-answer-line{font-family:'Montserrat',sans-serif;font-size:14px;color:#2C3E50 !important;
  background:#f4f6f7;border-radius:8px;padding:10px 14px;margin-top:8px;}
@media (max-width:600px){.nn-qb-tabs{overflow-x:auto;flex-wrap:nowrap;}}
	/* Premium reading layout */
.nn-qb-section{
  max-width:960px;
}

.nn-qb-card,
.nn-qb-section-title,
.nn-qb-subhead{
  box-sizing:border-box;
}

.nn-qb-card mjx-container{
  font-size:1.03em;
}

/* Keep marks / equations readable */
.nn-qb-card strong{
  font-weight:700;
}

/* Tablet */
@media (max-width:900px){

  .nn-qb-card{
    max-width:100%;
    padding:22px;
  }

  .nn-qb-card p,
  .nn-qb-subtext{
    font-size:16.5px;
  }
}

/* Mobile */
@media (max-width:640px){

  .nn-qb-section-title{
    font-size:21px;
  }

  .nn-qb-card{
    padding:18px 16px;
    border-radius:10px;
    margin-bottom:14px;
  }

  .nn-qb-card p,
  .nn-qb-subtext{
    font-size:16px;
    line-height:1.65;
  }

  .nn-qb-card h2,
  .nn-qb-card h3,
  .nn-qb-card h4,
  .nn-qb-card h5,
  .nn-qb-card h6,
  .nn-qb-card p.nn-qb-q-title{
    font-size:16px;
  }

  .nn-qb-subitem{
    gap:9px;
    padding:11px 0;
  }

  .nn-qb-subletter{
    flex-basis:20px;
    font-size:15px;
  }

  .nn-qb-subsubtext{
    font-size:15px;
  }
}