*{
    margin: 0;
    padding: 0;
}

html{
    scroll-behavior: smooth;
}

body{
    font-size: 100%;
    font-family: sans-serif;
}

div, section, span, ul, li, a, header{
    box-sizing: border-box;
}

/*css reset*/

header{
    width: 100%;
    display: flex;
    justify-content: space-between;
    padding: 20px 50px;
    align-items: center;
    position: fixed;
    z-index: 999;
}

#menu li{
    list-style: none;
    display: inline-block;
    margin: 20px;
}

#menu li a{
    color: #fff;
    text-decoration: none;
    font-size: 20px;
}

section{
    width: 100%;
    float: left;
    height: 100vh;
    position: relative;
}

#s1{
    background-image: url("images/ilksayfa.jpg");
    background-repeat: no-repeat;
    background-position: center center;
    background-attachment: fixed;
    background-size: cover;
}

#s2{
    background-image: url("images/ikincisayfa.jpg");
    background-repeat: no-repeat;
    background-position: center center;
    background-attachment: fixed;
    background-size: cover;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
}

#s3{
    background-image: url("images/ucuncusayfa.jpg");
    background-repeat: no-repeat;
    background-position: center center;
    background-attachment: fixed;
    background-size: cover;
}

#s4{
     background-color: #3C2C3E;
}

#s5{
    background-image: url("images/sonsayfa.jpg");
    background-repeat: no-repeat;
    background-position: center center;
    background-attachment: fixed;
    background-size: cover;
}

h1{
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    color: #fff;
    background-color: rgba(0, 0, 0, 0.342);
    background-position: center;
    background-size: 100px;
}

h2{
    position: absolute;
    top: 75%;
    left: 50%;
    transform: translate(-50%, -50%);
    color: #fff;
    background-position: center;
    background-size: 100px;
}