header {
  border-bottom: 2px solid #007bff;
  padding: 10px;
  background-color: #f8f9fa;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

a {
  font-weight: bold;
  color: #007bff;
  text-decoration: none;
}

a:hover,
a:focus {
  color: #0056b3;
  text-decoration: none;
  outline: none;
}

a:focus {
  outline: 2px solid #0056b3;
  outline-offset: 2px;
}

.logo {
  font-size: 2rem;
  font-weight: bold;
  color: skyblue;
  transition: color 0.3s ease;
  text-decoration: none;
}

.logo:hover,
.logo:focus {
  color: #007bff;
  outline: none;
}

.right {
  display: flex;
  justify-content: flex-end;
  padding: 10px;
  margin-top: 10px;
  gap: 10px;
}

.right img {
  cursor: pointer;
  transition: opacity 0.3s ease;
}

.right img:hover,
.right img:focus {
  opacity: 0.8;
  outline: none;
}

main {
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  padding: 20px;
}

article {
  flex: 3;
  padding-right: 20px;
}

aside {
  flex: 1;
  background-color: #f2f2f2;
  padding: 10px;
  font-style: italic;
  border-left: 3px solid #007bff;
}

aside ul {
  list-style: none;
  padding: 0;
}

aside li {
  margin-bottom: 15px;
}

aside i {
  margin-right: 8px;
  color: #555;
  transition: color 0.3s ease;
}

aside a:hover i,
aside a:focus i {
  color: #007bff;
  outline: none;
}

img {
  max-width: 100%;
  height: auto;
}

#smart_thumbnail.small,
.small {
  width: 200px;
  cursor: pointer;
  transition: width 0.3s ease-in-out;
}

input:focus {
  border: 2px solid #00ff00;
  outline: none;
}

@media (max-width: 768px) {
  main {
    flex-direction: column;
  }

  article,
  aside {
    flex: 1 0 100%;
    padding: 10px 0;
  }

  .right {
    justify-content: center;
    margin: 10px 0;
  }
}