body {
  background-color: #ffffff;
  font-size: 16px;
  line-height: 1.5;
  margin: 0;
  padding: 0;
}

i{
    font-size: 1.5em;
    margin-right: 5px;
}

a:hover {
  color: #5fbcff;
  border-bottom: 1px solid #ccc;
  border-color: #0077cc;
  animation: colorChange 0.5s ease-in-out forwards 0.5s;
  animation-delay: 0.5s;
}

a:focus {
  outline: none;
  animation-duration: inherit;
  animation-fill-mode: inherit;
  animation-iteration-count: inherit;
  animation-direction: inherit;
  animation-name: none;
}

a::view-transition {
  transition: color 0.3s ease-in-out, border-color 0.3s ease-in-out;
}

a:active {
  color: #3281b9;
  border-color: #0663a6;
}

.container{
    max-width: 800px;
    margin: 0 auto;
    padding: 0 20px;
}

a[id="back"]{
    text-align: center;
    empty-cells: show;
}

center{
    text-align: center;
    margin: auto;
}

a {
  /*动画效果
  animation: colorChange 0.5s ease-in-out forwards 0.5s;  
  animation-delay: 0.5s;*/
    color: #9faeff;
    border:#333 1px solid;
    padding: 3px 5px;
    border-radius: 1px;
    transition: color 0.3s ease-in-out;
}

@keyframes colorChange {
  0% {
    color: #5fbcff;
  }
  50% {
    color: #0077cc;
  }
  100% {
    color: #5fbcff;
  }
}
/* Header */
header {
  background-color: #fff;
  border-bottom: 1px solid #ccc;
  padding: 20px 0;
}

h1,
h2,
h3,
h4,
h5 {
  font-weight: normal;
  margin-bottom: 10px;
  text-align: center;
  transform: matrix3d(1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1);
  transform-origin: 50% 50% 0;
  transition: transform 0.3s ease-in-out;
}

h1 {
  font-size: 32px;
  margin: 0;
  padding: 0;
  transform: matrix3d(1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1);
  transform-origin: 50% 50% 0;
  transition: transform 0.3s ease-in-out;
  quotes: "“" "”" "‘" "’";
  position: relative;
  top: 10px;
  white-space: pre-wrap;
  word-wrap: break-word;
  overflow: hidden;
  text-align: center;
  font-family: 'Franklin Gothic Medium', 'Arial Narrow', Arial, sans-serif;
}

h2 {
  font-size: 24px;
  margin: 0;
  padding: 0;
}

h3 {
  font-size: 18px;
  margin: 0;
  padding: 0;
  white-space: pre-wrap;
  word-wrap: break-word;
  overflow: hidden;
  text-align: center;
  font-family: 'Franklin Gothic Medium', 'Arial Narrow', Arial, sans-serif;
}

h4 {
  font-size: 16px;
  margin: 0;
  padding: 0;
}

h5 {
  font-size: 14px;
  margin: 0;
  padding: 0;
}

/* Layout */
.container {
  max-width: 800px;
  margin: 0 auto;
  padding: 0 20px;
}

/* Header */
header {
  background-color: #fff;
  border-bottom: 1px solid #ccc;
  padding: 20px 0;
}

p {
  text-align: center;
  margin-bottom: 20px;
  font-size: 1.1em;
  font-family: 'Franklin Gothic Medium', 'Arial Narrow', Arial, sans-serif;
  
}


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

nav li {
  display: inline-block;
  margin-right: 20px;
  color: #fff;
  font-size: 1.2em;
}


nav a:hover {
  color: #5fbcff;
  border-bottom: 1px solid #ccc;
  border-color: #0077cc;
  animation: colorChange 0.5s ease-in-out forwards 0.5s;
  animation-delay: 0.5s;
}

/* Main */
main {
  padding: 20px 0;
}

/* Footer */
footer {
  background-color: #333;
  color: #fff;
  padding: 20px 0;
}

footer p {
  margin: 0;
}

/* Forms */
form {
  margin: 0;
  padding: 0;
}

label {
  display: block;
  margin-bottom: 0.5em;
}

input[type="text"],
input[type="email"],
input[type="password"],
textarea {
  border: 1px solid #ccc;
  border-radius: 4px;
  padding: 8px;
  width: 100%;
}

input[type="submit"] {
  background-color: #0077cc;
  border: none;
  border-radius: 4px;
  color: #fff;
  cursor: pointer;
  font-size: 1em;
  padding: 10px 20px;
}

/* Media queries */
@media (max-width: 768px) {
  .container {
    padding: 0 10px;
  }

  nav li {
    margin-right: 10px;
  }
}
@media (max-width: 480px) {
  h1 {
    font-size: 24px;
  }

  h2 {
    font-size: 18px;
  }

  h3 {
    font-size: 16px;
  }

  h4 {
    font-size: 14px;
  }

  h5 {
    font-size: 12px;
  }
}
nav {
  background-color: #333;
    color: #fff;
    padding: 10px;
    text-align: center;
    bottom: 0;
    left: 0;
    right: 0;
    z-index: 999;
    /* position: fixed; */
    width: 100%;
    height: 50px;
    display: flex;
    justify-content: space-around; /* 水平均匀分布导航项 */
    align-items: center; /* 垂直居中 */
    box-shadow: 0 2px 5px rgb(255, 128, 0);
}