body {
    height: 100%;
    width: 100%;
    margin: 0;
}

#container {
    position: relative;
    height: 400px;
    width: 80%;
    border: 2px solid brown;
    background-color: lightyellow;
    margin: 0% 10% 0% 10%;
    overflow: hidden;
}

#bird {
    position: absolute;
    background: url('bird.png');
    height: 42px;
    width: 65px;
    background-size: contain;
    background-repeat: no-repeat;
    top: 20%;
    left: 15%;
}

.pole {
    position: absolute;
    height: 130px;
    width: 75px;
    background-color: brown;
    right: -50px;
}

.pillar {
    position: absolute;
    height: 130px;
    width: 75px;
    background-color: brown;
    right: 500px;
}

#pole_1 {
    top: 0;
}

#pole_2 {
    bottom: 0;
}

#pole_3 {
    top: 0;
}

#pole_4 {
    bottom: 0;
}

#score_div {
    text-align: center;
    font-size: 40px;
    display: inline-block;
    margin-left: 14%;    
/*    margin-top: 1%;*/
    font-family: Tahoma;
    color: rgb(30,20,30);
}

#bbtn {
    position: relative;
    height: 60px;
    width: 250px;
/*    padding: 20px;*/
    background-color: crimson;
    color: white;
    font-size: 30px;
    border: none;
    cursor: pointer;
/*    letter-spacing: 10px;*/
  /*  -webkit-border-radius: 5px;
    -moz-border-radius: 5px;
    border-radius: 5px;*/
    text-align: center;
    transition: background-color 1s , color 1s , letter-spacing 1s;
}

#bbtn:hover {
    background-color: white;
    color: crimson;
    border: 2px solid crimson;
    transition: background-color 1s , color 1s , letter-spacing 1s;
    letter-spacing: 5px;
}


#restart_btn {
    position: absolute;
    top: 0;
    height: 17%;
    width: 100%;
    padding: 20px;
    background-color: crimson;
    color: white;
    font-size: 35px;
    border: none;
    cursor: pointer;
    display: none;
    letter-spacing: 10px;
  /*  -webkit-border-radius: 5px;
    -moz-border-radius: 5px;
    border-radius: 5px;*/
    text-align: center;
    transition: background-color 1s , color 1s , letter-spacing 1s;
}

#enter {
    font-size: 10px;
}

#restart_btn:hover {
    background-color: white;
    color: crimson;
    border: 2px solid crimson;
/*    letter-spacing: 20px;*/
    transition: background-color 1s , color 1s , letter-spacing 1s;
}

h1 {
    margin-left: 37%;
    font-size: 50px;
    font-family: Slim Joe;
}