body {
  font-family: "TASA Explorer", sans-serif;
  font-optical-sizing: auto;
  font-weight: 400;
  font-style: normal;
  background: #212121;
  color: #ffffff;
  display: flex;
  flex-direction: column;
  overflow: auto;
}

header {
  position: fixed;
  top: 20px;
  left: 20px;
  right: 20px;
  background: #333333;
  display: flex;
  align-items: center;
  border-radius: 8px;
  box-shadow: 0 2px 8px #00000088;
  box-sizing: border-box;
}

nav {
  padding: 15px 20px;
  display: flex;
  gap: 18px;
  font-size: 22px;
  font-weight: bold;
  overflow-x: auto;
  width: 100%;
}

.link {
  color: #777777;
  text-decoration: none;
  transition: 0.2s;
}

.link:hover,
.link:focus {
  color: #aaaaaa;
  text-decoration: none;
}

.logo {
  text-decoration: none;
  animation: rainbow 10s linear infinite;
}

@keyframes rainbow {
  0%,
  100% {
    color: red;
  }
  14% {
    color: orange;
  }
  28% {
    color: yellow;
  }
  42% {
    color: green;
  }
  57% {
    color: skyblue;
  }
  71% {
    color: blue;
  }
  85% {
    color: purple;
  }
  100% {
    color: red;
  }
}

.content-box {
  background: #111111;
  padding: 20px 40px;
  width: 100%;
  max-width: 50em;
  border-radius: 8px;
  box-shadow: 0 2px 8px #00000088;
  box-sizing: border-box;
}

.popup {
  position: fixed;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  z-index: 1000;
}

.close-btn {
  position: absolute;
  top: 10px;
  right: 10px;
  background: transparent;
  border: none;
  color: #ffffff;
  font-size: 24px;
  cursor: pointer;
}

.close-btn:hover {
  color: #ff5555;
}

.bold {
  font-weight: bold;
}

p {
  line-height: 1.8;
}

main {
  flex: 1;
  margin-top: 10vh;
  display: flex;
  justify-content: center;
}

.center {
  display: flex;
  justify-content: center;
  align-items: center;
  min-height: 80vh;
}