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


html {
    scroll-behavior: smooth;
}


body {
    color: #333;
    background: #fff;
}


.container {
    width: 90%;
    max-width: 1200px;
    margin: auto;
}



/* HEADER */

header {

    position: fixed;
    top: 0;
    width: 100%;
    background: white;
    z-index: 1000;
    padding: 18px 0;
    box-shadow: 0 3px 10px rgba(0,0,0,0.08);

}


header .container {

    display: flex;
    justify-content: space-between;
    align-items: center;

}



.logo img {

    width: 160px;

}



nav a {

    text-decoration: none;
    color: #222;
    margin-left: 25px;
    font-size: 16px;

}


nav a:hover {

    color:#009fe3;

}





/* HERO */

.hero {

    height: 100vh;

    background-image:

    linear-gradient(
        rgba(0,0,0,0.45),
        rgba(0,0,0,0.45)
    ),

    url("../images/hero.png");


    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;


    display:flex;
    align-items:center;


}



.hero-content {

    width:90%;
    max-width:1200px;
    margin:auto;
    color:white;

}



.hero h1 {

    font-size:55px;
    line-height:1.2;
    margin-bottom:20px;

}



.hero p {

    font-size:20px;
    max-width:600px;
    line-height:1.6;
    margin-bottom:30px;

}



.btn {

    display:inline-block;
    padding:14px 35px;
    background:#009fe3;
    color:white;
    text-decoration:none;
    border-radius:30px;

}



.btn:hover {

    background:#007bb3;

}





/* HİZMETLER */

.services {

    padding:90px 0;
    background:#f7f7f7;

}



.services h2 {

    text-align:center;
    font-size:35px;
    margin-bottom:50px;

}



.cards {

    display:grid;
    grid-template-columns:repeat(4,1fr);
    gap:25px;

}



.card {

    background:white;
    padding:20px;
    border-radius:15px;
    text-align:center;
    box-shadow:0 5px 15px rgba(0,0,0,.08);

}



.card img {

    width:100%;
    height:180px;
    object-fit:cover;
    border-radius:10px;

}



.card h3 {

    margin:20px 0 10px;

}



.card p {

    line-height:1.5;

}





/* PROJE */

.projects {

    padding:90px 0;

}



.projects h2 {

    text-align:center;
    font-size:35px;
    margin-bottom:40px;

}



.projects img {

    width:100%;
    border-radius:15px;

}





/* İLETİŞİM */


.contact {

    padding:80px 0;
    background:#0b1d2a;
    color:white;
    text-align:center;

}


.contact h2 {

    font-size:35px;
    margin-bottom:20px;

}


.contact p {

    margin:10px;

}





/* FOOTER */


footer {

    background:#050b10;
    color:white;
    text-align:center;
    padding:20px;

}





/* MOBİL */


@media(max-width:900px){


header .container {

    flex-direction:column;

}


nav {

    margin-top:15px;

}


.hero h1 {

    font-size:38px;

}


.cards {

    grid-template-columns:1fr;

}


}
```