* {
  padding: 0;
  margin: 0;
  box-sizing: border-box;
}

:root {
  font-size: 62.5%;
  --nav-height: 6.8rem;

  --accent-clr: hsl(194, 97%, 31%);
  --text-clr: hsl(240, 9%, 89%);
}

body {
  font-family: 'Roboto', sans-serif;
  color: var(--text-clr);

  width: 100%;
  height: 100%;
  background-color: hsl(210, 100%, 7%);
  background-image: url('/app/assets/bg-1.jpg');
  background-repeat: no-repeat;
  background-position: center;
  background-size: cover;
  overflow-x: hidden;

  background-attachment: fixed;
}

body.universe {
  background-image: url('/app/assets/bg-2.jpg');

  background-color: hsl(210, 100%, 7%);
  background-repeat: no-repeat;
  background-position: center;
  background-size: cover;
  overflow-x: hidden;
}

body.explore {
  background-image: url('/app/assets/bg-3.jpg');

  background-color: hsl(210, 100%, 7%);
  background-repeat: no-repeat;
  background-position: center;
  background-size: cover;
  overflow-x: hidden;
}

body.home li:nth-child(1) {
  font-weight: 700;
}

body.universe li:nth-child(2) {
  font-weight: 700;
}

body.explore li:nth-child(3) {
  font-weight: 700;
}

a {
  text-decoration: none;
  color: var(--text-clr);
}

img {
  position: absolute;
  top: 4rem;
  left: 4rem;
}

nav {
  padding: 0 7.2rem;
  position: relative;

  padding: 5rem 0 0;

  width: 100%;
}

nav ul {
  font-size: 1.2rem;
  line-height: 150%;

  list-style: none;

  display: flex;
  flex-wrap: wrap;
  justify-content: flex-start;
  gap: 3.2rem;

  margin-left: 7rem;

  width: 100%;
  padding: 0 5.2rem;
  text-align: center;
}

nav ul li {
  position: relative;
  font-size: clamp(1.4rem, 1.6rem + 0.2vw, 1.8rem);
  font-weight: 400;
}

nav ul li::after {
  content: '';
  width: 0;
  height: 3px;
  display: block;
  position: absolute;
  bottom: -0.2rem;
  left: 0;
  background-color: var(--accent-clr);
  transition: width 250ms;
}

nav ul li:hover::after {
  width: 100%;
}

.active {
  font-weight: bold;
}

#root {
  min-height: calc(100vh - var(--nav-height));
  width: 100vw;
  display: grid;
}

main {
  width: min(64.8rem, 100vw);
}

main.land {
  align-self: center;
  justify-self: center;
  text-align: center;
}

main.content {
  align-self: center;
  justify-self: flex-start;
  padding: 0 4rem;
}

main.land h1 {
  font-size: clamp(3.8rem, 4rem + 0.2vw, 6rem);
}

main.content h1 {
  font-size: clamp(4rem, 4.2rem + 0.2vw, 4.8rem);
  line-height: 125%;
}

main.content p {
  font-weight: 400;
  font-size: clamp(1.4rem, 1.4rem + 0.2vw, 1.8rem);
  line-height: 160%;
}

main.land .btn {
  color: var(--text-clr);
  font-size: 1.4rem;

  display: inline-block;
  padding: 1.2rem 3.2rem;
  background: transparent;

  border: 2px solid #ffffff;
  border-radius: 5px;

  margin-top: 2.4rem;
  cursor: pointer;

  transition: background 200ms, color 250ms;
}

main.land .btn:hover {
  background: #ffffff;
  color: var(--accent-clr);
}

@keyframes loading {
  0% {
    opacity: 0;
    background-size: 1600% 1600%;
  }

  75% {
    opacity: 1;
    filter: brightness(3);
    background-size: 100% 100%;
  }
  100% {
    opacity: 1;
    filter: brightness(1);
    background-size: 120% 120%;
  }
}