.main-nav .logo img {
      height: 80px;
      margin-top: 10px;
      transition: all 0.3s ease; 
    }
    .background-header .main-nav .logo img {
      height: 70px;
      margin-top: 0; 
    }  
    .background-header .main-nav .logo {
      line-height: 80px;  
      display: flex;
      align-items: center;  
    }
    @media (max-width: 768px) {
     .main-nav .logo img {
      height: 60px;
      margin-top: 0; 
       max-width: 300px;
    }
    .background-header .main-nav .logo img {
      height: 60px;
      margin-top: 9px; 
    }

    }
    .hero-slider {
      position: relative;
      height: auto;  /* let it shrink to fit content */
      min-height: 100vh; /* still fill the screen */
      color: #fff;
      display: flex;
      align-items: center;
      overflow: hidden;
    }


    .hero-slider .slider {
      position: absolute;
      top: 0; left: 0;
      width: 100%; height: 100%;
    }

    .hero-slider .slide {
      position: absolute;
      width: 100%; height: 100%;
      background-size: cover;
      background-position: center;
      opacity: 0;
      transition: opacity 1s ease-in-out;
    }

    .hero-slider .slide.active {
      opacity: 1;
    }

    .hero-slider .overlay {
      position: absolute;
      top: 0; left: 0;
      width: 100%; height: 100%;
      background: rgba(0,0,0,0.55); /* darker overlay */
      z-index: 1;
    }

    .hero-slider .container {
      position: relative;
      z-index: 2;
    }

    .hero-slider h6 {
      font-size: 18px;
      font-weight: 600;
      letter-spacing: 1px;
      color: #ff4444; /* red for subtitle */
      margin-bottom: 15px;
      text-transform: uppercase;
    }

    .hero-slider h2 {
      font-size: 52px;
      font-weight: 800;
      color: #fff; /* default white */
      line-height: 1.3;
      text-shadow: 2px 2px 8px rgba(0,0,0,0.7);
      margin-bottom: 20px;
    }

    .hero-slider h2 em { 
      color: #1e90ff; /* Blue for Research, Knowledge */
      font-style: normal;
    }

    .hero-slider h2 span { 
      color: #ff4444; /* Red for Global */
      font-weight: 800;
    }

    .hero-slider p {
      font-size: 18px;
      color: #f1f1f1;
      line-height: 1.6;
      margin-top: 10px;
      max-width: 650px;
      text-shadow: 1px 1px 6px rgba(0,0,0,0.6);
    }
    .white-text {
      color: #fff !important;
    }
    /* Remove bottom spacing from banner */
    .main-banner {
      margin-bottom: 0 !important;
      padding-bottom: 0 !important;
    }

    /* Remove top spacing from about section */
    #about {
      margin-top: 0 !important;
      padding-top: 40px; /* adjust if needed */
    }

    .books-section {
      padding: 80px 0;
      background: #f9fafc;
      text-align: center;
      position: relative;
      z-index: 1; /* keeps section above footer */
    }

    .books-section .section-title {
      font-size: 32px;
      font-weight: 700;
      margin-bottom: 40px;
      color: #222;
      position: relative;
    }

    .books-carousel {
      display: block;
      position: relative;
      z-index: 2;
    }

    .book-item {
      text-align: center;
      padding: 15px;
      background: #fff;
      border-radius: 12px;
      overflow: hidden;
      box-shadow: 0 6px 15px rgba(0,0,0,0.15);
      transition: transform 0.3s ease, box-shadow 0.3s ease;
    }

    .book-item img {
      width: 100%;
      height: auto;        /* fixed frame height */
      object-fit: contain;  /* show full image, no cropping */
      border-radius: 8px;
      background: #fff;     /* clean background */
      box-shadow: 0 4px 12px rgba(0,0,0,0.15);
      display: block;
    }

    .book-item h4 {
      margin-top: 12px;
      font-size: 16px;
      font-weight: 600;
      color: #333;
    }

    .book-item:hover {
      transform: translateY(-6px);
      box-shadow: 0 12px 25px rgba(0,0,0,0.2);
    }

    /* Owl Carousel Navigation */
    .owl-carousel .owl-nav button {
      background: #ff4444;
      border-radius: 50%;
      width: 40px;
      height: 40px;
      color: #fff !important;
      font-size: 18px;
      line-height: 1;
      transition: 0.3s;
    }

    .owl-carousel .owl-nav button:hover {
      background: #222;
    }
