*{
margin:0;
padding:0;
box-sizing:border-box;
font-family:Arial,Helvetica,sans-serif;
}

body{

background:#f2f4ef;

}

.container{

width:90%;

max-width:700px;

margin:50px auto;

background:white;

padding:35px;

border-radius:15px;

box-shadow:0 10px 25px rgba(0,0,0,.15);

text-align:center;

}

h1{

color:#556B2F;

margin-bottom:10px;

}

h2{

margin-bottom:20px;

color:#333;

}

p{

color:#666;

margin-bottom:30px;

line-height:1.8;

}

button{

width:100%;

padding:18px;

margin-top:15px;

background:#556B2F;

color:white;

border:none;

border-radius:10px;

font-size:18px;

cursor:pointer;

transition:.3s;

}

button:hover{

background:#3d4e22;

transform:scale(1.02);

}

#levels{

display:none;

margin-top:30px;

}

#study{

display:none;

margin-top:30px;

}

#levelTitle{

margin-bottom:20px;

color:#556B2F;

}