body {
  font-family: Arial, sans-serif;
  margin: 0;
  background: #f5f5f5;
  color: #333;
}

header {
  background: white;
  padding: 20px;
  text-align: center;
}

header a{
  color: #333;
  text-decoration: none;

}

nav a {
  margin: 0 10px;
  text-decoration: none;
  color: #333;
}

.container {
  max-width: 900px;
  margin: 0 auto;
  padding: 40px 20px;
}

section {
  background: white;
  padding: 30px;
  margin-bottom: 30px;
  border-radius: 8px;
  box-shadow: 0 2px 6px rgba(0,0,0,0.05);
}

section:last-child {
  border-bottom: none;
}

.mode {
  display: block;
  margin-left: auto;

  width: 100px;
  text-align: center;
  text-decoration: none;
  line-height: 30px;
  cursor: pointer;
  border-radius: 4px;
  font-size: 14px;
  outline: none;
  appearance: none;
  -webkit-appearance: none;
  color: #000000a7;
  border:1px solid #000000a7;
  background-color: #fff;
  -webkit-transition: all .3s;
  transition: all .3s;
}
.mode:hover {
  color: #fff;
  border:1px solid #000000a7;
  background-color: #000000a7;
}

footer {
  display: block;
  margin-left: auto;
  padding: 10px;
}

.image-box {
  width: 100%;
  max-width: 400px;
  height: 200px;
  overflow: hidden;
}

.image-box img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}
@media (max-width: 768px) {

  header {
    padding: 15px;
  }

  nav a {
    display: inline-block;
    margin: 5px;
  }

  section {
    padding: 20px;
  }

  .image-box {
    height: 160px;
  }
}