body {
      margin: 0;
      padding: 0;
      font-family: Arial, sans-serif;
      background-image: url("kutuphaneresim.docx"); /* örnek kitaplık arka planı */
      background-size: cover;
      background-position: center;
    }

    .container {
      text-align: center;
      padding: 40px 20px;
      background-color: rgb(255, 255, 255);
      margin: 40px auto;
      max-width: 900px;
      border-radius: 10px;
    }

    h1 {
      font-size: 40px;
      font-weight: bold;
      color: #333;
    }

    select, button {
      padding: 10px;
      margin: 10px;
      font-size: 16px;
    }

    .section {
      display: inline-block;
      width: 250px;
      vertical-align: top;
      margin: 20px;
      background: #facfcf;
      padding: 15px;
      border-radius: 8px;
      box-shadow: 0 0 10px rgba(0,0,0,0.2);
    }

    .footer {
      text-align: center;
      padding: 10px;
      font-size: 14px;
      color: #0f0f0f;
    }

    .footer span {
      float: right;
    }

    .bold {
      font-weight: bold;
    }

    .underline {
      text-decoration: underline;
    }

    label {
      display: block;
      margin: 5px 0;
      text-align: left;
    }

    .centered-button {
      display: block;
      margin: 10px auto;
    }
  
    
  
      .top-bar {
        display: flex;
        justify-content: flex-end;
        background-color: #333;
        padding: 10px 20px;
      }
  
      .top-bar button {
        margin-left: 10px;
        padding: 8px 16px;
        color: white;
        background-color: #007BFF;
        border: none;
        cursor: pointer;
        border-radius: 5px;
      }
  
      .top-bar button:hover {
        background-color: #0056b3;
      }
  
      .modal {
        display: none;
        position: fixed;
        top: 60px;
        right: 20px;
        background-color: #f9f9f9;
        border: 1px solid #ccc;
        padding: 20px;
        width: 300px;
        box-shadow: 0 4px 8px rgba(0,0,0,0.2);
        border-radius: 10px;
        z-index: 1000;
      }
  
      .modal input {
        width: 100%;
        padding: 10px;
        margin: 8px 0;
        box-sizing: border-box;
      }
  
      .modal button {
        background-color: #28a745;
        color: white;
        padding: 10px;
        width: 100%;
        border: none;
        border-radius: 5px;
        cursor: pointer;
      }
  
      .modal button:hover {
        background-color: #218838;
      }

      .main-header {
      background-color: #333;
      padding: 8px 20px;
      position: fixed;
      z-index: 1;
      width: 100%;
      top: 0px;
    }

    .main-nav {
      display: inline-block;
      justify-content: space-between;
      width: calc(100% - 101px);
      text-align: right;
      vertical-align: top;
    }

    .main-nav__items {
      margin: 0;
      padding: 0;
      list-style: none;
    }

    .main-nav__item {
      display: inline-block;
      margin: 0px 10px;
      content: none;
    }

    .main-nav__item a {
      text-decoration: none;
      color: #fff;
      font-weight: bold;
      padding: 8px 14px;
      border-radius: 6px;
      transition: all 0.3s ease;
    }