@charset "UTF-8";
/* CSS Document */

html {
  box-sizing: border-box;
  font-size: 16px;
}

*, *:before, *:after {
  box-sizing: inherit;
}

body {
  font-family: Arial, sans-serif;
  margin: 0;
}

#wrapper {
  max-width: 960px;
  margin: 0 auto;
}

header {
  background-color: #333;
  color: #fff;
  padding: 10px;
}

header h1 {
  margin: 0;
}


nav {
  background-color: #f2f2f2;
  border: 1px solid #ccc;
}

nav ul {
  margin: 0;
  padding: 0;
  list-style: none;
  display: flex;
  flex-wrap: wrap;
}

nav li {
  flex: 1 1 16.6667%;
  border-right: 1px solid #ccc;
  border-bottom: 1px solid #ccc;
  text-align: center;
  padding: 10px 0;
  cursor: pointer;
}

nav li:last-child {
  border-right: none;
}

nav li.home {
  background-color: #4CAF50;
  color: #fff;
}

nav li.contact {
  background-color: #f44336;
  color: #fff;
}

main {
  display: flex;
  flex-wrap: wrap;
}

.banner {
  display: block;
  width: 100%;
  height: auto;
}

aside {
  flex: 1 100%;
  padding: 10px;
  background-color: #f2f2f2;
}


.column-left,
.column-center,
.column-right {
  flex: 1 0 30%;
  margin: 10px;
  padding: 10px;
  background-color: #f2f2f2;
}

.column-left h2,
.column-center h2,
.column-right h2 {
  margin-top: 0;
}


footer {
  background-color: #333;
  color: #fff;
  text-align: center;
  padding: 10px;
}

@media only screen and (max-width: 768px) {
  nav li {
    flex-basis: 50%;
    border-right: none;
    border-bottom: 1px solid #ccc;
  }
  
  nav li:nth-child(even) {
    border-right: 1px solid #ccc;
  }
  
  .column-left,
  .column-center,
  .column-right {
    flex-basis: 100%;
  }
}

@media only screen and (max-width: 480px) {
  nav {
    overflow: auto;
  }
  
  nav ul {
    flex-wrap: nowrap;
  }
  
  nav li {
    flex-basis: auto;
    width: 25%;
    white-space: nowrap;
  }
  
  nav li:not(:last-child) {
    border-right: 1px solid #ccc;
  }
  
  .banner {
    height: 200px;
  }
}