add tutorial screen

public/src/css/main.css

@@ -130,3 +130,95 @@ html, body{
     transform: rotate(95deg);
     font-size: 90%;
 }
+
+
+#tutorial-outer {
+    display: flex;
+    justify-content: center;
+    align-items: center;
+    overflow: hidden;
+    position: absolute;
+    width: 100%;
+    height: 100%;
+}
+
+#tutorial {
+    background: rgb(246, 234, 212);
+    color: black;
+    border: 5px black solid;
+    border-radius: 10px;
+    height: 65%;
+    width: 50%;
+    padding: 20px;
+    font-size: 16pt;
+    position: relative;
+}
+
+#tutorial-title {
+    z-index: 1;
+    position: absolute;
+    color: white;
+    top: -25px;
+    font-size: 26pt;
+}
+
+#tutorial-content {
+    padding: 15px 30px;
+}
+
+kbd {
+    font-family: inherit;
+    padding: 0.1em 0.6em;
+    border: 1px solid #ccc;
+    font-size: 13px;
+    background-color: #f7f7f7;
+    color: #333;
+    -moz-box-shadow: 0 1px 0px rgba(0, 0, 0, 0.2),0 0 0 2px #ffffff inset;
+    -webkit-box-shadow: 0 1px 0px rgba(0, 0, 0, 0.2), 0 0 0 2px #ffffff inset;
+    box-shadow: 0 1px 0px rgba(0, 0, 0, 0.2), 0 0 0 2px #ffffff inset;
+    -moz-border-radius: 3px;
+    -webkit-border-radius: 3px;
+    border-radius: 3px;
+    display: inline-block;
+    text-shadow: 0 1px 0 #fff;
+    line-height: 1.4;
+    white-space: nowrap;
+}
+
+.taibtn {
+    bottom: 15px;
+    margin: 0 auto;
+    position: absolute;
+    right: 15px;
+    padding: 10px 40px;
+    border-radius: 15px;
+    border: 3px rgba(218, 205, 178, 1) solid;
+    cursor: pointer;
+}
+
+.taibtn:hover {
+    z-index: 1;
+    color: white;
+    background: rgb(255, 181, 71);
+    border-color: white;
+}
+
+.taibtn:before {
+    padding: 0 40px;
+}
+
+#tutorial-end-button {
+    font-size: 22pt;
+}
+
+#songsel-help {
+    float: right;
+    background: rgba(255, 255, 255, 0.5);
+    color: black;
+    padding: 15px;
+    margin: 10px;
+    font-size: 18px;
+    border: 3px black solid;
+    border-radius: 50px;
+    cursor: pointer;
+}