:root {
  --primary-color: #4A90E2;
  --secondary-color: #50E3C2;
  --accent-color: #f5a623;
  --light-color: #f8f9fa;
  --dark-color: #2c3e50;
  --text-color: #555;
  --bg-color: #ffffff;
  --card-bg: #ffffff;
  --border-color: #e9ecef;
  --shadow: 0 4px 20px rgba(0, 0, 0, 0.07);
}

body {
  background-color: var(--bg-color);
  font-family: 'Tiro Bangla';
  color: var(--text-color);
  line-height: 1.7;
  padding-top: 80px;
}

h1, h2, h3, h4, h5, h6 {
  font-family: 'Tiro Bangla', cursive;
  color: var(--dark-color);
  font-weight: 700;
}
.disabled {
  pointer-events: none;
  cursor: default;
  color: #6c757d; /* Bootstrap's muted text color */
}

/* --- Navbar --- */
@media (max-width: 991.98px) {
  .navbar-collapse {
    max-height: calc(100vh - 80px);
    overflow-y: auto;
    -webkit-overflow-scrolling: touch;
  }
  
  .dropdown-menu {
    position: static !important;
    transform: none !important;
    max-height: 300px;
    overflow-y: auto;
    border: 1px solid rgba(0,0,0,.15);
    margin: 0.5rem 0;
  }
  
  .dropdown-menu-mega {
    width: 100% !important;
  }
}

.navbar {
    box-shadow: 0 2px 10px rgba(0,0,0,0.05);
    transition: background-color 0.3s ease;
}

.navbar-brand img {
    height: 50px;
    transition: transform 0.3s ease;
}
.navbar-brand:hover img {
    transform: scale(1.05);
}

.nav-link {
    font-weight: 600;
    color: var(--dark-color) !important;
    transition: color 0.3s ease;
    margin: 0 0.5rem;
}
.nav-link:hover, .nav-link.active {
    color: var(--primary-color) !important;
}
.dropdown-menu {
    border-radius: 8px;
    box-shadow: var(--shadow);
    border: 1px solid var(--border-color);
}
.dropdown-item {
    transition: background-color 0.2s ease, color 0.2s ease;
}
.dropdown-item:hover {
    background-color: rgba(74, 144, 226, 0.1);
    color: var(--primary-color);
}
.dropdown-menu-mega {
  width: 800px;
  padding: 1.5rem;
}
.dropdown-header {
  font-weight: 700;
  color: var(--primary-color);
  padding: 0.25rem 0;
  margin-bottom: 0.5rem;
  border-bottom: 1px solid var(--border-color);
}

/* --- Loading Bar --- */
#loading-bar {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 4px;
  background-color: transparent;
  z-index: 9999;
  transition: opacity 0.5s ease-out;
}
#loading-progress {
  height: 100%;
  width: 0%;
  background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
  transition: width 0.5s ease;
  border-radius: 0 2px 2px 0;
}
.diagram-box {
            border: 1px solid #ccc;
            padding: 10px;
            margin: 15px 0;
            text-align: center;
            background-color: #f9f9f9;
        }

        .diagram-box img {
            max-width: 100%;
            height: auto;
        }

/* Responsive Adjustments for Mobile */
@media (max-width: 991.98px) {
  .navbar-nav .nav-item {
    margin: 0.5rem 0;
  }
  .dropdown-menu-mega {
    width: 100%;
    padding: 1rem;
  }
  .dropdown-menu-mega .col-lg-3 {
    width: 100%;
    margin-bottom: 1rem;
  }
  .dropdown-menu-mega .col-lg-3:last-child {
    margin-bottom: 0;
  }
  .dropdown-header {
    margin-top: 1rem;
  }
}

@media (max-width: 767.98px) {
  body {
    padding-top: 70px;
  }
}

   /* Footer Styles */
    footer {
      position: relative;
      z-index: 1;
    }

    footer h5 {
      font-family: 'Tiro Bangla', cursive;
      font-weight: 500;
      position: relative;
      padding-bottom: 10px;
      margin-bottom: 20px;
      color: rgb(255, 255, 255)
    }

    footer h5::after {
      content: '';
      position: absolute;
      left: 0;
      bottom: 0;
      width: 50px;
      height: 2px;
      background-color: var(--primary-color);
    }

    .footer-logo img {
      transition: transform 0.3s ease;
    }

    .footer-logo:hover img {
      transform: scale(1.05);
    }

    .social-icons a {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      width: 36px;
      height: 36px;
      background-color: rgba(255, 255, 255, 0.1);
      border-radius: 50%;
      margin-right: 8px;
      transition: all 0.3s ease;
    }

    .social-icons a:hover {
      background-color: var(--primary-color);
      transform: translateY(-3px);
    }

    footer ul li {
      transition: all 0.2s ease;
    }

    footer ul li:hover {
      padding-left: 5px;
    }

    footer ul li a {
      transition: color 0.2s ease;
    }

    footer ul li a:hover {
      color: var(--primary-color) !important;
    }

    /* Back to Top Button */
    .back-to-top {
      position: fixed;
      bottom: 20px;
      right: 20px;
      width: 50px;
      height: 50px;
      background-color: var(--primary-color);
      color: white;
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 20px;
      opacity: 0;
      visibility: hidden;
      transition: all 0.3s ease;
      z-index: 99;
    }

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

    .back-to-top:hover {
      background-color: var(--accent-color);
      transform: translateY(-3px);
    }

    .bg-green1 {
      --bs-bg-opacity : 1;
      background-color: rgb(64 89 91) !important;
    }
.pink {
  color: #ff00d4;
}