main.css

* {
  margin: 0;
  padding: 0;
}
body {
  background-image: url('wood.jpg');
  background-repeat: no-repeat;
  background-size: cover;
}
header {
  height: 50px;
  /* Permalink - use to edit and share this gradient: http://colorzilla.com/gradient-editor/#ebf1f6+0,abd3ee+50,89c3eb+59,d5ebfb+88 */
background: #ebf1f6; /* Old browsers */
background: -moz-linear-gradient(top,  #ebf1f6 0%, #abd3ee 50%, #89c3eb 59%, #d5ebfb 88%); /* FF3.6-15 */
background: -webkit-linear-gradient(top,  #ebf1f6 0%,#abd3ee 50%,#89c3eb 59%,#d5ebfb 88%); /* Chrome10-25,Safari5.1-6 */
background: linear-gradient(to bottom,  #ebf1f6 0%,#abd3ee 50%,#89c3eb 59%,#d5ebfb 88%); /* W3C, IE10+, FF16+, Chrome26+, Opera12+, Safari7+ */
filter: progid:DXImageTransform.Microsoft.gradient( startColorstr='#ebf1f6', endColorstr='#d5ebfb',GradientType=0 ); /* IE6-9 */

  border-bottom: 2px rgba(0,0,0,0.5);
  color:white;
  font-weight: bold;
  font-size: 1.2em;
  padding-left: 5px;
  padding-top: 5px;
}
select {
  color: black;
}
#start-btn {
  font-size: 5em;
  border-radius: 15px;
  margin-top: 20px;
  background-color: blue;
  padding: 5px;
}
#game-c {
  background-image: url('bg_tex.jpg');
  background-repeat: no-repeat;
  background-size: cover;
  margin-top: 50px;
}
#game {
  background: url('tx.jpg');
}