*{
      box-sizing:border-box;
      margin:0;
      padding:0;
      font-family:'Source Sans Pro',sans-serif;
    }

    body {
      min-height:100vh;
      display:flex;
      align-items:center;
      justify-content:center;
      background:#e9eff5;
    }

    .container {
      display:flex;
      width:1000px;
      background:#fff;
      border-radius:12px;
      overflow:hidden;
      box-shadow:0 4px 20px rgba(0,0,0,0.1);
    }

    /* Left side */
    .login-left {
      flex:1;
      background:linear-gradient(135deg,#2563eb,#1e40af);
      color:#fff;
      padding:50px;
    }
    .login-left h2 {
      font-size:28px;
      margin-bottom:20px;
    }
    .login-left ul {
      list-style:none;
    }
    .login-left ul li {
      margin:12px 0;
      font-size:16px;
    }
    .login-left ul li i {
      margin-right:10px;
      color:#cbd5e1;
    }

    /* Right side */
    .login-right {
      flex:1;
      padding:50px;
      display:flex;
      flex-direction:column;
      justify-content:center;
    }

    .login-right img {
      width:80px;
      height:80px;
      object-fit:cover;
      border-radius:50%;
      margin:0 auto 15px auto;
      display:block;
    }

    .login-right h3 {
      text-align:center;
      margin-bottom:25px;
      font-size:22px;
      color:#1f2937;
    }

    .form-floating-custom {
      position: relative;
      margin-bottom: 1.5rem;
      width: 100%;
    }
    .form-floating-custom input {
      width: 100%;
      padding: 14px 40px 14px 12px;
      border: 1px solid #ccc;
      border-radius: 6px;
      font-size: 16px;
      background: #f9fafb;
      color: #111;
    }
    .form-floating-custom label {
      position: absolute;
      left: 12px;
      top: 50%;
      transform: translateY(-50%);
      font-size: 16px;
      color: #6b7280;
      pointer-events: none;
      transition: 0.2s ease all;
    }
    .form-floating-custom input:focus + label,
    .form-floating-custom input:not(:placeholder-shown) + label {
      top: 12px;
      font-size: 14px;
      color: #2563eb;
    }
    .form-floating-custom .input-icon {
      position: absolute;
      right: 12px;
      top: 50%;
      transform: translateY(-50%);
      color: #9ca3af;
    }

    .btn-login {
      width:100%;
      padding:12px;
      background:#2563eb;
      color:#fff;
      font-size:16px;
      border:none;
      border-radius:6px;
      cursor:pointer;
      transition:0.3s;
    }
    .btn-login:hover {
      background:#1e40af;
    }

    .error-input {
      border: 1.5px solid red !important;
    }
    .error-message {
      color: red;
      font-size: 0.85em;
      display: flex;
      align-items: center;
      margin-top: -8px;
      margin-bottom: 10px;
    }
    .error-message i {
      margin-right: 4px;
      font-size: 0.9em;
    }

    /* --- Responsive --- */
@media (max-width: 992px) {
  .container {
    width: 95%;
    flex-direction: column;
  }

  .login-left, .login-right {
    flex: none;
    width: 100%;
    padding: 30px 20px;
    text-align: center;
  }

  .login-left {
    border-radius: 12px 12px 0 0;
  }

  .login-right {
    border-radius: 0 0 12px 12px;
  }

  .login-left h2 {
    font-size: 22px;
  }

  .login-left ul li {
    font-size: 14px;
  }

  .login-right h3 {
    font-size: 18px;
  }

  .form-floating-custom input {
    font-size: 14px;
    padding: 12px 35px 12px 10px;
  }

  .btn-login {
    font-size: 14px;
    padding: 10px;
  }
}

/* Mobile cực nhỏ */
@media (max-width: 576px) {
  body {
    padding: 10px;
  }

  .login-left {
    display: none;
  }

  .container {
    width: 100%;
    box-shadow: none;
  }

  .login-right {
    padding: 20px;
    border-radius: 12px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
  }

  .login-right img {
    width: 60px;
    height: 60px;
    margin-bottom: 10px;
  }

  .login-right h3 {
    font-size: 16px;
    margin-bottom: 15px;
  }

  .btn-login {
    font-size: 14px;
    padding: 8px;
  }
}

.form-floating-custom input {
  width: 100%;
  padding: 18px 40px 10px 12px; 
  border: 1px solid #ccc;
  border-radius: 6px;
  font-size: 16px;
  background: #f9fafb;
  color: #111;
  line-height: 2.0; 
}

.form-floating-custom input:focus {
  outline: none;             
  border: 1pt solid #2563eb;  
  box-shadow: none;          
}