html {
  color: #333333;
  background: #ffffff;
  scroll-behavior: smooth;
  -ms-text-size-adjust: 100%;
  -webkit-text-size-adjust: 100%;
  -moz-text-size-adjust: 100%;
  text-size-adjust: 100%;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  font-family: 'Cascadia Code', Consolas, Helvetica, 'Microsoft YaHei', 'PingFang SC', 'Hiragino Sans GB', sans-serif;
  overflow-y: overlay;
}
body {
  max-width: 680px;
  padding: 0 14px;
  margin: 0 auto;
}
.header {
  padding: 40px 0;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.header .logo {
  flex-shrink: 0;
  width: 40px;
  height: 40px;
  border-radius: 50%;
  margin-right: 10px;
  -webkit-user-drag: none;
  box-shadow: 0 0 6px 1px rgba(0, 0, 0, 0.18);
  background-image: url(../img/favicon.JPG);
  background-size: cover;
}
.hover-underline {
  position: relative;
}
.hover-underline:after {
  content: '';
  position: absolute;
  width: 100%;
  height: 1px;
  bottom: -2px;
  left: 0;
  background-color: #333333;
  visibility: hidden;
  transform: scaleX(0);
  transition: transform 200ms ease-in-out;
}
.hover-underline:hover:after {
  visibility: visible;
  transform: scaleX(1);
}
.header .menu {
  margin-right: -9px;
  text-align: right;
  user-select: none;
}
.header .menu a {
  display: inline-block;
  font-size: 16px;
  margin: 4px 9px;
  white-space: nowrap;
  user-select: auto;
}

@media screen and (max-width: 560px) {
  .header {
    padding: 35px 0 20px 0;
    justify-content: flex-start;
  }
  .header .menu {
    margin-right: -2px;
    text-align: left;
  }
  .header .menu a {
    margin: 2px 5px;
    font-size: 15px;
  }
}