* {
  box-sizing: border-box;
}
.row::after {
  content: "";
  clear: both;
  display: table;
}
.header1 {
 display: flex;
 flex-wrap: wrap;

 font-size: 1em;
 color: white;
 background-color: green;
 border: 1px solid springgreen;
 padding: 2px;
}
.header2 {
 display: flex;
 flex-wrap: wrap;

  font-size:3em;
  color: white;

 background-color: black;
 border: 1px solid springgreen;
 padding: 10px;
}

 .footer {
 display: flex;
 flex-wrap: wrap;
justify-content: center;
 background-color: black;
 border: 2px solid springgreen;
 padding: 10px;
 color: white;
 text-align: center;
 font-size: 1em;
 position: fixed;
 bottom: 0;
 width: 97%;
 }
 /* Six buttons with code link to some pages in this project */
 .button-group {
 display: flex;
 flex-wrap: wrap;
 justify-content: center;
 align-items: center;
 margin-top: 20px;
 }
 .button {
 display: inline-block;
 padding: 4px;
 margin: 4px;
 background-color: GREEN;
 color: white;
 border: 1px solid black;
 border-radius: 4px;
 font-size: 1em;
 text-align: center;
 text-decoration: none;
 }

 /* Fixed background */
 body {

   background-color: #FFFFFF;
   background-image: url('space33.jpg');
   background-attachment: fixed;
   background-position: center center;
   background-repeat: repeat;
   background-size: 100% 100%;
   color: #000000;
   font-family: Arial;
   font-weight: normal;
   font-size: 13px;
   line-height: 1.1875;
   margin: 0;
   padding: 0;


 }

        #gameArea {
            width: 1000px;
            height: 500px;
            background-color: transparent;
            border: 1px solid SKYBLUE;
            position: relative;
        }


          				.buttone {
            width: 50px;
            height: 50px;
            background-color: springgreen;
             border: 2px solid red;
             border-radius: 30%;
             padding: 6px;
             margin: 6px;
            display: inline-block;
            text-align: center;
            color: red;
            line-height: 6px;
            cursor: pointer;
        }




            #character {
            width: 70px;
            height: 40px;
            background-image: url('canon1.png');
            position: absolute;
            bottom: 0;
            left: 0;

        }
        .bullet {
            width: 200px;
            height: 70px;
            background-image: url('bullets1.png');

            position: absolute;

        }
        .enemy {
            width: 100px;
            height: 60px;
            background-image: url('enemy1.png');
            position: absolute;  position: absolute;
        top: 0px;
        left: 60px;

        animation: moveEnemy 3s infinite;
    }
    @keyframes moveEnemy {
        0% {
            transform: translate(0, 0);
        }
        25% {
            transform: translate(100px, 100px);
        }
        50% {
            transform: translate(0, 200px);
        }
        75% {
            transform: translate(-100px, 100px);
        }
        100% {
            transform: translate(0, 0);
        }

        }




         /* Flexible layout responsive design */

 .header1 {
 font-size: 0.5em;
 padding: 2px;
 }
 /* Big red header with red border */
 .header2 {
 font-size: 4em;
 padding: 2px;
 }
 /* Six buttons with code link to some pages in this project */
 .button-group {
 margin-top: 10px;
 }
 .button {
 padding: 5px;
 margin: 5px;
 font-size: 1em;
 }



.row {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
}
.column {
  flex: 100%;

  padding: 5px;
}
.column img {

  width: 100%;
  height: auto;

      }
@media screen and (max-width: 600px) {
  .column {

    width: 100%;
  }


}