@font-face {
  font-family: icon;
  src: url(/assets/iconfont.woff2);
}
@font-face {
  font-family: code;
  src: url(/assets/code.woff2);
}

@keyframes main-fade-in {
  0% {
    opacity: 0;
    transform: translateY(30px);
  }
  50% {
    opacity: 0.8;
    transform: translateY(2px);
  }
}

ico {
  font-family: icon;
}

body {
  margin: 0;
  width: 100vw;
  height: 100vh;
  overflow: hidden;
  background-color: #555;
  background-image: linear-gradient(135deg, #555 70%, #666 100%);
  color: #dcc;
  font-family: 'Sarasa UI SC', 'Microsoft JhengHei', 'PingFang SC', sans-serif;
  user-select: none;
  -webkit-user-select: none;
  /* ===vars=== */
  --def: #dcc;
  --lighter-bg: #222;
  --light-bg: #333;
  --def-bg: #444;
  --gray-bg: #555;
  --hover: #345;
  --hover-bg: #edd;
  --act: #ccc;
  --act-bg: #766;
  --button: #fee;
  --param: #fff;
}


button {
  display: flex;
  height: 50px;
  font-size: 20px;
  padding: 0 25px 0 5px;
  margin-right: 20px;
  outline: none;
  border: none;
  color: var(--hover);
  background-color: var(--button);
  box-shadow: 0 0 5px 0 #fff inset;
  transition: background-color 0.2s, color 0.2s;
  border-radius: 25px;
  line-height: 50px;
  overflow: hidden;
}
button:hover {
  background-color: var(--hover-bg);
  box-shadow: 0 0 0 1px #fff inset, 0 0 0 2px #fff;
  border: 3px solid inset var(--button);
}
button:active {
  background-color: var(--act-bg);
  color: var(--act);
}
button > ico {
  padding: 0 5px;
  font-size: 36px;
}


body::before {
  content: "6778";
  font-family: code, monospace;
  position: absolute;
  font-size: 150px;
  line-height: 150px;
  right: -40px;
  bottom: -30px;
  color: #fff1;
}

body > header {
  height: 60px;
  width: 100%;
  background-color: #444;
  box-shadow: 0 0 5px #444;
  display: flex;
  font-size: 16px;
  line-height: 60px;
  font-weight: bold;
  justify-content: flex-end;
}
body > header::after {
  content: "";
  width: 60px;
}
body > header > div {
  padding: 0 20px;
  transition: background-color 0.2s, color 0.2s;
}
body > header > div:hover {
  background-color: var(--hover-bg);
  color: var(--hover);
}
body > header > div:active {
  color: var(--act);
  background-color: var(--act-bg);
}
body > header > ico {
  position: absolute;
  left: 20px;
  top: 0;
  font-size: 40px;
  line-height: 60px;
}

body > main {
  height: calc(100% - 60px);
  display: flex;
  justify-content: center;
}
body > main > div {
  animation: main-fade-in 0.5s;
  height: 100%;
}