/* Base styles */
body {
  font-family: 'Segoe UI', sans-serif;
  margin: 0;
  padding: 0;
  background-color: #fff;
  color: #222;
}

/* Container */
#all {
  width: 90%;
  max-width: 1200px;
  margin: 0 auto;
}

/* Header */
#head {
  background-color: #203731;
  color: #fff;
  padding: 20px;
  text-align: center;
}

#head h1 {
  margin-bottom: 5px;
}

#head nav a {
  color: #ffc107;
  text-decoration: none;
  font-weight: bold;
  padding: 0 10px;
}

#head nav a:hover {
  text-decoration: underline;
}

/* Content Sections */
#side, #main, #right {
  float: left;
  padding: 20px;
  box-sizing: border-box;
}

#side {
  width: 20%;
  background-color: #f0f0f0;
}

#main {
  width: 50%;
  background-color: #ffffff;
}

#right {
  width: 30%;
  background-color: #f9f9f9;
}

/* Footer */
#foot {
  clear: both;
  background-color: #203731;
  color: #fff;
  padding: 20px;
  text-align: center;
  margin-top: 20px;
}

/* Responsive Layout */
@media screen and (max-width: 768px) {
  #side, #main, #right {
    float: none;
    width: 100%;
  }

  #head, #foot {
    text-align: center;
  }
}