* {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
      font-family: Arial, Helvetica, sans-serif;
    }

    body {
      background: url("https://ditanex.net/static/media/wallpaper.3c39ecb9ba8174c061f0.png") no-repeat center center/cover;
      background-size: cover;
      color: white;
      min-height: 100vh;
      overflow-x: hidden;
    }

    /* Header */
    header {
      display: flex;
      justify-content: space-between;
      align-items: center;
      padding: 15px 5%;
      background-color: rgba(0, 0, 0, 0.9);
    }

    header img {
      height: 40px;
      max-width: 100%;
    }

    .buttons {
      display: flex;
      gap: 10px;
    }

    .btn {
      padding: 10px 15px;
      border-radius: 5px;
      border: none;
      cursor: pointer;
      font-weight: bold;
      transition: 0.3s;
      font-size: 14px;
    }

    .btn-primary {
      background-color: #00A8FF;
      color: white;
    }

    .btn-dark {
      background-color: #333;
      color: white;
    }

    .btn:hover {
      opacity: 0.8;
    }

    /* Main content */
    .main-content {
      position: relative;
      width: 100%;
      min-height: 80vh;
      display: flex;
      flex-direction: column;
      justify-content: center;
    }

    .overlay-text {
      width: 90%;
      max-width: 550px;
      position: relative;
      margin: 40px auto;
      text-align: center;
      padding: 20px;
      border-radius: 8px;
    }

    .overlay-text h1 {
      font-size: 2.5rem;
      margin-bottom: 20px;
      color: #fff;
      line-height: 1.2;
    }

    .overlay-text p {
      font-size: 1rem;
      color: #858585;
      line-height: 1.5;
      margin-bottom: 25px;
    }

    .overlay-text .button {
      padding: 15px 25px;
      font-size: 16px;
      background-color: #1e90ff;
      color: #000000;
      border: none;
      border-radius: 6px;
      cursor: pointer;
      transition: background-color 0.3s ease;
      font-weight: bold;
    }

    .overlay-content {
      width: 90%;
      max-width: 650px;
      margin: 0 auto;
      text-align: center;
    }

    .overlay-content img {
      width: 100%;
      height: auto;
      max-width: 100%;
    }

    /* Overlay tối */
    .overlay {
      position: fixed;
      top: 0; left: 0;
      width: 100%; height: 100%;
      background: rgba(0,0,0,0.7);
      display: none;
      z-index: 999;
    }

    /* Khung login panel */
    .login-panel {
      position: fixed;
      top: 0; 
      right: -100%;
      width: 100%;
      max-width: 400px;
      height: 100%;
      background: #0d1b2a;
      color: white;
      padding: 20px;
      box-shadow: -2px 0 10px rgba(0,0,0,0.5);
      transition: right 0.4s ease;
      z-index: 1000;
      overflow-y: auto;
    }

    .login-panel.active {
      right: 0;
    }

    .login-header {
      display: flex;
      justify-content: space-between;
      align-items: center;
      margin-bottom: 20px;
    }

    .login-header .logo {
      height: 40px;
    }

    .close-btn {
      background: none;
      border: none;
      font-size: 28px;
      color: white;
      cursor: pointer;
    }

    /* Form */
    .login-form {
      margin-top: 20px;
      display: flex;
      flex-direction: column;
    }

    .login-form label {
      margin: 10px 0 5px;
      font-size: 14px;
    }

    .login-form input {
      padding: 12px;
      border-radius: 6px;
      border: 1px solid #333;
      background: #1b263b;
      color: white;
      font-size: 16px;
    }

    .login-form a {
      font-size: 13px;
      color: #4da3ff;
      margin: 10px 0;
      text-decoration: none;
    }

    .btn-submit {
      background: #2196f3;
      border: none;
      color: white;
      padding: 12px;
      border-radius: 6px;
      cursor: pointer;
      margin-top: 15px;
      font-size: 16px;
    }

    .login-footer {
      font-size: 13px;
      margin-top: 20px;
      text-align: center;
    }
    
    .login-footer a {
      color: #4da3ff;
      text-decoration: none;
    }
    
    /* Lỗi required text */
    .error {
      font-size: 12px;
      color: red;
      margin-bottom: 10px;
      display: block;
    }

    /* Media Queries */
    /* Tablet */
    @media (min-width: 768px) {
      .overlay-text {
        text-align: left;
        margin-left: 10%;
        margin-top: 0;
      }
      
      .overlay-content {
        margin-right: 5%;
      }
      
      .main-content {
        flex-direction: row;
        align-items: center;
        justify-content: space-between;
      }
    }

    /* Desktop */
    @media (min-width: 1024px) {
      header {
        padding: 15px 50px;
      }
      
      .overlay-text {
        width: 550px;
        position: absolute;
        top: 40%;
        left: 20%;
        transform: translate(-50%, -50%);
        margin: 0;
      }
      
      .overlay-content {
        width: 650px;
        position: absolute;
        top: 40%;
        left: 65%;
        transform: translate(-50%, -50%);
        margin: 0;
      }
      
      .overlay-content img {
        width: 100%;
      }
      
      .btn {
        padding: 10px 20px;
        font-size: 16px;
      }
    }

    /* Mobile */
    @media (max-width: 767px) {
      header {
        flex-direction: column;
        gap: 15px;
        padding: 15px 20px;
      }
      
      .overlay-text h1 {
        font-size: 2rem;
      }
      
      .buttons {
        width: 100%;
        justify-content: center;
      }
      
      .btn {
        flex: 1;
        max-width: 140px;
      }
    }

    /* Small mobile */
    @media (max-width: 480px) {
      .overlay-text h1 {
        font-size: 1.8rem;
      }
      
      .overlay-text p {
        font-size: 0.9rem;
      }
      
      .login-panel {
        padding: 15px;
      }
    }