style_3.css

body {
    background-image: url("bg_ca.svg");
    background-repeat: no-repeat;
    background-size: cover;
}

#a {
    width: 25%;
    height: 40px;
    margin-top: 23%;
    margin-left: 28%;
    box-sizing: border-box;
    border: 2px solid #ccc;
    -webkit-transition: 0.5s;
    transition: 0.5s;
    outline: none;
    word-spacing: 2px;
    font-weight: 400;
    letter-spacing: 2px;
}

#a:focus {
    border: 2px solid #000000;
}

#b {
    width: 25%;
    height: 40px;
    margin-top: 3%;
    margin-left: 38%;
    font-weight: 400;
    box-sizing: border-box;
    border: 2px solid #ccc;
    -webkit-transition: 0.5s;
    transition: 0.5s;
    outline: none;
    word-spacing: 2px;
}

#b:focus {
    border: 2px solid #000000;
}

#stop {
    margin-left: 10px;
    width: 10%;
    height: 40px;
    border: 2px;
    border-style: solid;
    background-color: rgb(0, 0, 0);
    color: rgb(255, 255, 255);
    font-weight: 800;
}

#start {
    margin-left: 10px;
    width: 10%;
    height: 40px;
    border: 2px;
    border-style: solid;
    background-color: rgb(0, 0, 0);
    color: rgb(255, 255, 255);
    font-weight: 800;
}

#github {
    position: absolute;
    margin-top: 12%;
    margin-left: 5%;
}

.ls {
    color: rgb(36, 36, 36);
    text-decoration: none;
    font-weight: 600;
    font-size: small;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    margin-left: 10px;
}

.mner {
    visibility: hidden;
    height: 0px;
    width: 0px;
}

#footer {
    position: fixed;
    left: 0px;
    bottom: 0px;
    /* height: 30px; */
    width: 100%;
    /* background: #999; */
}

.alert {
    padding: 20px;
    background-color: rgb(32, 32, 32);
    color: rgb(184, 184, 184);
    font-size: 14px;
    font-weight: 600;
    font-family: 'Lucida Sans', 'Lucida Sans Regular', 'Lucida Grande', 'Lucida Sans Unicode', Geneva, Verdana, sans-serif;
}

.closebtn {
    margin-left: 15px;
    color: white;
    font-weight: bold;
    float: right;
    font-size: 20px;
    line-height: 18px;
    cursor: pointer;
    transition: 0.3s;
}

.closebtn:hover {
    color: rgb(54, 54, 54);
}