body {
    background: #f6f7fb;
  }

  .content-area {
    background: #fff;
    border: 1px solid rgba(0,0,0,.08);
    border-radius: 14px;
    padding: 18px 18px;
    box-shadow: 0 10px 30px rgba(0,0,0,.06);
  }

  .toolbar-wrap {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 10px;
  }

  .quiz-toolbar {
    display: flex;
    gap: 6px;
    flex-wrap: wrap;
    justify-content: center;
  }

  .quiz-toolbar .btn {
    font-size: 16px;
    border-radius: 12px;
    padding: 5px 14px;
  }

  .explain-area {
    background: #fff;
    border: 1px solid rgba(0,0,0,.08);
    border-radius: 14px;
    padding: 18px 18px;
    box-shadow: 0 10px 30px rgba(0,0,0,.06);
    top: 90px;
    max-height: calc(100vh - 120px);
    overflow: auto;
  }

  .explain-header {
    border-bottom: 1px solid rgba(0,0,0,.07);
    padding-bottom: 10px;
    margin-bottom: 14px;
  }

  .answer-status {
    display: flex;
    align-items: center;
    gap: 10px;
  }

  .badge-dot {
    width: 10px;
    height: 10px;
    border-radius: 50%;
    display: inline-block;
  }

  .badge-dot.ok {
    background: #16a34a;
  }

  .badge-dot.bad {
    background: #dc2626;
  }

  .question-card h5 {
    line-height: 1.35;
  }

  .option-item {
    border: 1px solid rgba(0,0,0,.10);
    border-radius: 10px;
    padding: 12px 12px;
    margin-bottom: 10px;
    cursor: pointer;
    transition: .15s ease;
    user-select: none;
  }

  .option-item:hover {
    background: rgba(2,132,199,.06);
  }

  .option-item input {
    margin-right: .5rem;
  }

  .option-item.selected {
    border-color: rgba(2,132,199,.45);
    background: rgba(2,132,199,.08);
  }

  .option-item.correct {
    border-color: rgba(22,163,74,.55);
    background: rgba(22,163,74,.10);
  }

  .option-item.wrong {
    border-color: rgba(220,38,38,.55);
    background: rgba(220,38,38,.10);
  }

  .question-card.locked .option-item {
    pointer-events: none;
    opacity: .9;
    cursor: default;
  }

  .step {
    background: #f4f6fb;
    border: 1px solid rgba(0,0,0,.06);
    border-radius: 10px;
    padding: 10px 12px;
    margin: 10px 0;
  }

  .step-title {
    font-weight: 600;
    margin-bottom: 6px;
  }

  .math-chip {
    display: inline-block;
    background: #e9eefc;
    border-radius: 10px;
    padding: 6px 10px;
    margin: 6px 0;
    font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;
  }

  .seg-progress {
    height: 10px;
    display: flex;
    gap: 4px;
    border-radius: 999px;
    overflow: hidden;
  }

  .seg-progress .seg {
    height: 100%;
    border-radius: 999px;
    background: #adb5bd;
  }

  #explainFab {
    position: fixed;
    left: 50%;
    bottom: 16px;
    transform: translateX(-50%);
    z-index: 1080;
    border-radius: 999px;
    padding: 10px 14px;
    box-shadow: 0 10px 25px rgba(0, 0, 0, .18);
    display: none;
    font-size: 16px;
  }

  @media (max-width: 991.98px) {
    #right-col {
      display: none !important;
    }
  }

  @media (min-width: 992px) {
    #explainFab {
      display: none !important;
    }
  }

  .modal-body {
    max-height: 70vh;
    overflow: auto;
  }

  .text-muted {
    padding-bottom: 5px;
  }

  .bg-success {
    background-color: rgb(51 241 153) !important;
  }

  .bg-danger {
    background-color: rgb(249 33 54) !important;
  }

  .bg-info {
    background-color: rgb(18 204 241) !important;
  }

  footer {
    background: #1a1d29;
    color: white;
    padding: 3rem 2rem 1.5rem;
  }

  .footer-content {
    max-width: 1200px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-bottom: 2rem;
  }

  .footer-section h4 {
    margin-bottom: 1rem;
    color: var(--accent-color);
  }

  .footer-section ul {
    list-style: none;
  }

  .footer-section ul li {
    margin-bottom: 0.5rem;
  }

  .footer-section a {
    color: rgba(255, 255, 255, 0.7);
    text-decoration: none;
    transition: color 0.3s ease;
  }

  .footer-section a:hover {
    color: white;
  }

  .footer-bottom {
    text-align: center;
    padding-top: 2rem;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    color: rgba(255, 255, 255, 0.6);
  }

  .hero-content {
    max-width: 800px;
    margin: 0 auto;
    position: relative;
    z-index: 1;
  }

  .hero h1 {
    font-size: 29px;
    margin-bottom: 1rem;
    font-weight: 700;
    text-align: center;
  }

  .hero p {
    font-size: 1.2rem;
    margin-bottom: 0;
    opacity: 0.95;
    text-align: center;
    max-width: 850px;
    margin-left: auto;
    margin-right: auto;
  }

  .fa-calculator:before {
    content: "\f1ec";
    color: #2196F3;
  }
  
  math, 
math * {
   
    font-family: math, "Latin Modern Math", "STIX Two Math", "Cambria Math", serif !important;
    
    line-height: normal !important;
    
  
    text-transform: none !important;
    letter-spacing: normal !important;
    word-spacing: normal !important;
}


math mn {
    font-variant-numeric: lnum !important;
    font-style: normal !important;
}

math mi {
    font-style: italic !important;
}

math mo {
    font-family: math, "STIX Two Math", serif !important;
    margin: 0 !important;
    padding: 0 !important;
}

math msqrt, 
math mroot, 
math mfrac {
    overflow: visible !important;
}

.math-chip {
    /*display: inline-flex;*/
    align-items: baseline;
    gap: 4px;
}	 
	
#test-content > div.question-card > div > label,
#test-content > div.question-card > div > label * {
    font-size: 18px !important;
}


#test-content > div.question-card div label math,
#test-content > div.question-card div label math * {
    font-family: math, "Latin Modern Math", serif !important;
}

.fa-check-circle
{color:green;}