/* Scroll to Top Button */
.scroll-to-top {
  position: fixed;
  bottom: 30px;
  right: 30px;
  width: 50px;
  height: 50px;
  border-radius: 50%;
  background-color: var(--primary-color);
  color: white;
  border: none;
  cursor: pointer;
  opacity: 0;
  visibility: hidden;
  transition: all 0.3s ease;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.2);
  z-index: 99;
}

.scroll-to-top:hover {
  background-color: #3367d6;
  transform: translateY(-3px);
}

.scroll-to-top.visible {
  opacity: 1;
  visibility: visible;
}

.scroll-to-top svg {
  width: 24px;
  height: 24px;
}
  .calculator-card {
        border-radius: 15px;
        box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
        transition: transform 0.3s;
        margin-bottom: 25px;
      }
      .calculator-card:hover {
        transform: translateY(-5px);
      }
      .viz-container {
        height: 300px;
        background: #f8f9fa;
        border-radius: 10px;
        margin-top: 20px;
      }
      .nav-tabs .nav-link.active {
        font-weight: bold;
        border-bottom: 3px solid #0d6efd;
      }
      #cryptoChart,
      #solar3d-container,
      #finance3d-chart {
        width: 100%;
        height: 100%;
      }
      .loading-spinner {
        display: flex;
        flex-direction: column;
        align-items: center;
        justify-content: center;
        height: 100%;
        color: #666;
      }

      .molecule-viewer-container {
        max-width: 800px;
        margin: 0 auto;
        padding: 20px;
      }

      #molecule3d-container canvas {
        display: block;
        width: 100% !important;
        height: 100% !important;
      }

      * {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

body {
    background-color: #f5f5f5;
    color: #333;
    line-height: 1.6;
}
h1 {
    text-align: center;
    margin-bottom: 30px;
    color: #2c3e50;
}

.calculator-types {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    margin-bottom: 20px;
    justify-content: center;
}

.calc-btn {
    padding: 10px 15px;
    background-color: #3498db;
    color: white;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    font-size: 16px;
    transition: all 0.3s ease;
}

.calc-btn:hover {
    background-color: #2980b9;
}

.calc-btn.active {
    background-color: #2c3e50;
}

.calculator {
    background-color: white;
    border-radius: 10px;
    padding: 20px;
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.1);
    display: none;
}

.calculator.show {
    display: block;
}

.display {
    margin-bottom: 15px;
}

.display input {
    width: 100%;
    padding: 15px;
    font-size: 24px;
    text-align: right;
    border: 1px solid #ddd;
    border-radius: 5px;
    background-color: #f9f9f9;
}

.buttons {
    display: grid;
    grid-template-columns: repeat(5, 1fr);
    gap: 10px;
}

.scientific-calc .buttons {
    grid-template-columns: repeat(5, 1fr);
}

.standard-calc .buttons {
    grid-template-columns: repeat(4, 1fr);
}

.btn {
    padding: 15px;
    font-size: 18px;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    transition: all 0.2s ease;
}

.btn:hover {
    background-color: #7de2e2;
}

.operator {
    background-color: #bdc3c7;
    color: #2c3e50;
}

.operator:hover {
    background-color: #a6acaf;
}

.equals {
    background-color: #2ecc71;
    color: white;
}

.equals:hover {
    background-color: #27ae60;
}

.zero {
    grid-column: span 2;
}

.number-system {
    display: flex;
    gap: 10px;
    margin-bottom: 15px;
}

.num-btn {
    padding: 8px 12px;
    background-color: #ecf0f1;
    border: none;
    border-radius: 5px;
    cursor: pointer;
}

.num-btn.active {
    background-color: #3498db;
    color: white;
}

.bmi-form, .loan-form, .age-form {
    display: flex;
    flex-direction: column;
    gap: 15px;
}

.input-group {
    display: flex;
    flex-direction: column;
    gap: 5px;
}

.input-group label {
    font-weight: bold;
}

.input-group input {
    padding: 10px;
    border: 1px solid #ddd;
    border-radius: 5px;
    font-size: 16px;
}

.calculate-btn {
    padding: 12px;
    background-color: #2ecc71;
    color: white;
    border: none;
    border-radius: 5px;
    font-size: 16px;
    cursor: pointer;
    transition: background-color 0.3s ease;
}

.calculate-btn:hover {
    background-color: #27ae60;
}

.result {
    margin-top: 20px;
    padding: 15px;
    background-color: #f9f9f9;
    border-radius: 5px;
    font-size: 18px;
    text-align: center;
}

.bmi-info {
    margin-top: 10px;
    padding: 10px;
    background-color: #e8f4fc;
    border-radius: 5px;
    font-size: 16px;
}

@media (max-width: 768px) {
    .buttons {
        grid-template-columns: repeat(4, 1fr);
    }
    
    .scientific-calc .buttons {
        grid-template-columns: repeat(4, 1fr);
    }
    
    .calculator-types {
        flex-direction: column;
        align-items: center;
    }
}