body {
      padding-top: 80px;
      background-color: #f0f2f5; /* Lighter background for a modern feel */
      font-family: 'Inter', sans-serif;
    }
.logo {
    height: 180px;
    border-radius: 20%;
}
    .course-content h1 {
      font-weight: 700;
      text-align: center;
      margin-bottom: 30px;
      color: #343a40; /* Darker text for contrast */
    }

    .course-content h2 {
      font-size: 1.8rem; /* Slightly larger for section titles */
      color: #007bff; /* Primary blue for section titles */
      margin-top: 30px;
      font-weight: 600;
    }

    .course-content ul {
      list-style: none;
      padding-left: 0;
    }

    .course-content ul li {
      background: #ffffff;
      border: 1px solid #e9ecef; /* Lighter border */
      border-left: 4px solid #007bff; /* Primary blue left border */
      margin-bottom: 15px;
      padding: 15px;
      border-radius: 8px;
      transition: all 0.3s ease;
    }

    .course-content ul li:hover {
      box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
      transform: translateY(-3px); /* Slightly more pronounced lift */
    }

    .course-content ul li a {
      font-weight: 600;
      color: #007bff; /* Primary blue for links */
      text-decoration: none;
    }

    .course-content ul li p {
      margin: 5px 0 0 0;
      color: #6c757d;
    }

    footer {
      margin-top: 60px;
      background-color: #343a40;
      color: #ffffff;
      padding: 20px 0;
      text-align: center;
    }

    .fade-in {
      opacity: 0;
      animation: fadeIn 1s ease-in-out forwards;
    }

    @keyframes fadeIn {
      to {
        opacity: 1;
      }
    }

    .btn-animate:hover {
      transform: scale(1.05);
      box-shadow: 0 4px 12px rgba(0, 0, 0, 0.2);
      transition: 0.3s ease-in-out;
    }

    /* Hero Section Specifics */
    .hero-section {
      background: linear-gradient(135deg, #d4dd74, #3ccde0); /* Stronger blue gradient */
      padding: 80px 20px;
      text-shadow: 0 2px 4px rgba(0, 0, 0, 0.4);
      position: relative; /* For potential overlays */
      overflow: hidden;
      border-bottom-left-radius: 25px;
      border-bottom-right-radius: 25px;
    }
    .hero-section::before {
        content: '';
        position: absolute;
        top: 0;
        left: 0;
        right: 0;
        bottom: 0;
        /*background: url('https://placehold.co/1920x400/007bff/ffffff?text=CHEMISTRY+LEARNING') no-repeat center center; /* Placeholder for a subtle chemistry pattern */
        background: url('../assets/images/chembgImage2.jpg');
        background-size: cover;
        opacity: 0.1; /* Subtle overlay */
        z-index: 0;
    }
    .hero-section > .container {
        position: relative;
        z-index: 1;
    }


    .section-title {
      font-size: 1.75rem;
      font-weight: 700; /* Bolder */
      margin-bottom: 15px;
      color: #343a40; /* Dark text for readability */
    }

    .section-text {
      font-size: 1.1rem;
      color: #495057;
      line-height: 1.6;
    }

    .card-title {
      font-size: 1.35rem; /* Slightly larger */
      font-weight: 700; /* Bolder */
      color: #343a40; /* Dark text */
      display: flex;
      align-items: center;
      margin-bottom: 15px;
    }
    .card-title i {
      color: #17a2b8; /* Vibrant teal for icons */
      margin-right: 10px;
      font-size: 1.5rem;
    }

    .topic-card {
      transition: all 0.3s ease-in-out;
      border-radius: 16px;
      background-color: #ffffff; /* Clean white background */
      border: none; /* Remove default border */
      box-shadow: 0 4px 15px rgba(0, 0, 0, 0.08); /* Softer shadow */
    }

    .topic-card:hover {
      transform: translateY(-8px); /* More pronounced lift on hover */
      box-shadow: 0 8px 25px rgba(0, 0, 0, 0.15); /* Stronger shadow on hover */
    }

    .topic-card ul li {
      padding: 8px 0; /* More padding for list items */
      border: none; /* Remove default list item border */
      border-left: 3px solid #6c757d; /* Subtle gray left border for list items */
      margin-bottom: 8px; /* Smaller margin between list items */
      background-color: transparent; /* Transparent background for list items */
      border-radius: 0; /* No border radius for list items */
      transition: all 0.2s ease;
    }
    .topic-card ul li:hover {
        background-color: #f8f9fa; /* Light background on hover for list items */
        transform: translateX(5px); /* Slight shift on hover */
        box-shadow: none; /* No shadow on list item hover */
    }

    .topic-card ul li a {
      font-weight: 500;
      color: #007bff; /* Primary blue for links */
      text-decoration: none;
      display: block; /* Make link fill the list item */
      padding-left: 10px; /* Indent links slightly */
    }

    .topic-card ul li a:hover {
      text-decoration: underline;
      color: #0056b3; /* Darker blue on hover */
    }

    .responsive-chemist-img {
      max-width: 100%;
      height: auto;
      border-radius: 16px; /* More rounded corners */
      box-shadow: 0 6px 20px rgba(0, 0, 0, 0.15); /* Stronger shadow */
      transition: transform 0.4s ease-in-out;
    }

    .responsive-chemist-img:hover {
      transform: scale(1.05); /* More pronounced zoom */
    }

    /* Adjustments for the summary & quiz section */
    .section.text-center.mt-5 {
        padding-top: 30px;
        padding-bottom: 30px;
        background-color: #ffffff;
        border-radius: 16px;
        box-shadow: 0 4px 15px rgba(0, 0, 0, 0.08);
        margin-top: 40px !important;
    }
    .section.text-center.mt-5 h4 {
        color: #343a40;
        font-weight: 700;
        font-size: 1.6rem;
    }
    .section.text-center.mt-5 .btn {
        margin-top: 20px;
    }
    .text-orange { /* Renaming to be more generic if needed, but keeping for now */
        color: #fd7e14 !important; /* Bootstrap orange */
    }
    .text-alert { /* Renaming to be more generic if needed, but keeping for now */
        color: #ffc107 !important; /* Bootstrap yellow */
    }