* {
    box-sizing: border-box;
}

html, body {
    margin: 0;
    padding: 0;
}

header {
    padding: 20px 0;
}

nav {
    margin: 0;
    text-align: center;
}

nav li {
    display: inline-block;
    font-family: 'Raleway', sans-serif;
    font-weight: 600;
    font-size: 20px;
    width: 100px;
}

nav a {
    text-decoration: none;
    color:white;
}

a:hover {
    opacity: 0.5;
}

footer {
    padding: 20px 0;
    text-decoration: none;
    color:white;
    font-weight: 600;
    font-size: 12px;
    font-family: 'Raleway', sans-serif;
}

.background-color {
    background-color: #353839;
}

#home {
    background-image: url("certificates_images/background.jpg");
    background-size: cover;
    background-attachment: fixed;
    background-position: top;
    height: 1000px;
    overflow: hidden;
    text-align: center; 
    position: relative;
    width: 100%;
    padding: 0;
    margin: 0;
}

#home .content {
    position: relative;
    font-size: 36px;
    line-height: 0px;
    top: 100px;
    font-family: 'Raleway', sans-serif;
}

#home .content h2 {
    font-size: 24px;
}

#about {
    text-align: center;
    padding: 10px 50px;
}

#about h2 {
    font-size: 46px;
}

#certifications h2, #contact h2, #projects h2 {
    font-size: 30px;
    margin: 20px 10px;
}

#about p {
    font-size: 24px;
    line-height: 50px;
    margin: 20px 10px;
}

#certifications li, #contact p, #projects p {
    font-size: 20px;
    line-height: 25px;
    margin: 20px 10px;
}

#certifications {
    border-top: 10px solid #353839;
}

#certifications a {
    text-decoration: none;
    margin: 20px 10px;
}

#projects, #contact {
    border: 1px solid transparent;
}

#projects {
    color: white;
}

#projects li {
    display: inline-block;
    margin: 20px;
}

#projects li img {
    width: 250px;
    height: 250px;
    
}

img:hover {
    opacity: 0.5;
}