style.css

body {
    margin: 0;
    padding: 0;
    width: 100%;
    font-family: 'Raleway', sans-serif;
    font-size: 16px;
    background-color: #BF9A54;
    color: #38401D;
}

.wrapper {
    width: 80%;
    margin: auto;
    max-width: 1200px;
}

/* HEADER SECTION */

.header {
    overflow: hidden;
}

header h1 {
    /* float: left; */
    font-size: 160%; 
    display: inline-block;     
}

/* END HEADER SECTION */

/* NAVIGATION */

nav {
    float: right;
}

nav ul li {
    list-style: none;
    float: left;
    margin-left: 20px;
}

nav ul li a {
    text-decoration: none;
    font-size: 130%;
    font-weight: 600;
    color: #544333;  
}

nav ul li a:hover {
    color: #C0B6A8;
}

/* END NAVIGATION */

/* SECTIONS */
section:after {
    content: " ";
    display: block;
    clear: both;
}

section div.container img {
    width: 33.33%;
    float: left;
    box-sizing: border-box;
    border: 1px solid transparent;
    opacity: 1;
    transition: opacity .5s;
}

section div.container img:hover {
   opacity: 0.65; 
}

section {
    margin-bottom: 3%;
}

section h2 {
    text-align: center;
}

/* END OF SECTIONS */

/* FOOTER SECTION */
.footer {
    overflow: hidden;
    text-align: center;
    padding-bottom: 10px;
}

.footer p {
    font-weight: 700;
}
/* END FOOTER SECTION */

/* MEDIA QUERIES/RESPONSIVE */
@media only screen and (max-width: 768px) {
    .wrapper {
        width: 100%;
    }
    
    header h1 {
        margin-left: 3%;
    }
    #menu-icon {
        width: 30px;
        height: 26px;
        background: url(images/menu.png) no-repeat center;
        position: absolute;
        top: 2%;
        right: 5%;
        z-index: 100;
    }
    nav ul {
        display: none;
        position: absolute;
        right: 5%;
        top: 0%;
        padding: 3% 7%;
        background: #C0B6A8;
        width: 200px;
        text-align: center;
        z-index: 10;
    }
    nav ul li {
        width: 90%;
        padding: 5%;
        margin: auto;
    }
    nav ul li a {
        padding: 5% 20%;
    }
    nav ul li a:hover {
        border-bottom: 1px solid #aaa;
    }

    nav:hover ul {
        display: block;
    }
    section div.container img {
        display: block;
        float: none;
        width: 100%;
        height: auto;
    }
}

@media only screen and (min-width: 768px) and
(max-width: 1024px) {
    .wrapper {
        width: 100%;
    }
    header h1 {
        margin-left: 3%; 
    }
    nav {
        margin-right: 3%;
    }
}

/* Scroll to Top */
/* https://www.w3schools.com/howto/howto_js_scroll_to_top.asp */
#myBtn {
    display: none; /* Hidden by default */
    position: fixed; /* Fixed/sticky position */
    bottom: 10px; /* Place the button at the bottom of the page */
    right: 30px; /* Place the button 30px from the right */
    z-index: 99; /* Make sure it does not overlap */
    border: none; /* Remove borders */
    outline: none; /* Remove outline */
    background-color: inherit; /* Set a background color */
    color: inherit; /* Text color */
    cursor: pointer; /* Add a mouse pointer on hover */
    padding: 3px 5px; /* Some padding */
    border-radius: 10px; /* Rounded corners */
    font-size: 14px; /* Increase font size */
}

#myBtn:hover {
    background-color: #555; /* Add a dark-grey background on hover */
}
/* The Modal (background) */
.modal {
    display: none; /* Hidden by default */
    position: fixed; /* Stay in place */
    z-index: 1; /* Sit on top */
    padding-top: 100px; /* Location of the box */
    left: 0;
    top: 0;
    width: 100%; /* Full width */
    height: 100%; /* Full height */
    overflow: auto; /* Enable scroll if needed */
    background-color: rgb(0,0,0); /* Fallback color */
    background-color: rgba(0,0,0,0.9); /* Black w/ opacity */
  }
  
  /* Modal Content (image) */
  .modal-content {
    margin: auto;
    display: block;
    width: 80%;
    max-width: 700px;
  }
  
  /* Caption of Modal Image */
  #caption {
    margin: auto;
    display: block;
    width: 80%;
    max-width: 700px;
    text-align: center;
    color: #ccc;
    padding: 10px 0;
    height: 150px;
  }
  
  /* Add Animation */
  .modal-content, #caption {  
    -webkit-animation-name: zoom;
    -webkit-animation-duration: 0.6s;
    animation-name: zoom;
    animation-duration: 0.6s;
  }
  
  @-webkit-keyframes zoom {
    from {-webkit-transform:scale(0)} 
    to {-webkit-transform:scale(1)}
  }
  
  @keyframes zoom {
    from {transform:scale(0)} 
    to {transform:scale(1)}
  }
  
  /* The Close Button */
  .close {
    position: absolute;
    top: 15px;
    right: 35px;
    color: #f1f1f1;
    font-size: 40px;
    font-weight: bold;
    transition: 0.3s;
  }
  
  .close:hover,
  .close:focus {
    color: #bbb;
    text-decoration: none;
    cursor: pointer;
  }