*,
::before,
::after {
  box-sizing: border-box;
}

body {
  position: relative;
  margin: 0;
  overflow: hidden;
  display: flex;
  height: 100vh;
  flex-direction: column;
  line-height: 1.5;
  font-family: "Montserrat", sans-serif;
  font-size: 62.5%;
  color: #00ff00;
  background-color: #ff0000;
}

.smooth {
  position: relative;
  width: 100%;
  height: 100%;
  scroll-behavior: smooth;
  overflow-y: scroll;
  scroll-snap-type: mandatory;
  scroll-snap-points-y: repeat(100vh);
  scroll-snap-type: y mandatory;
}

.header {
  position: fixed;
  top: 0;
  z-index: 1;
  display: flex;
  width: 100%;
  min-height: 60px;
  font-size: 1rem;
  background-image: linear-gradient(180deg, #1d1e22, rgba(29, 30, 34, 0.1), transparent);
  mix-blend-mode: luminosity;
}
.header ul {
  margin: 0;
  padding: 0;
  list-style-type: none;
  display: flex;
  width: 100%;
  justify-content: center;
}
.header ul li {
  margin: 0 1em;
  padding: 1em;
}
.header ul li a {
  position: relative;
  text-decoration: none;
  text-transform: uppercase;
  font-weight: 600;
  color: #f4f4f4;
}
.header ul li a::after {
  position: absolute;
  bottom: -3px;
  left: 0;
  content: "";
  width: 0;
  height: 3px;
  transition: all 0.2s linear;
}
.header ul li a:hover::after {
  width: 100%;
  background-color: #f0f0f0;
}

section {
  position: relative;
  display: flex;
  width: 100%;
  min-height: 100vh;
  flex-flow: column wrap;
  align-items: center;
  justify-content: center;
  font-size: 1rem;
  background-color: #f4f4f4;
  background-image: url(BG4a.jpg);
  background-size: cover;
  scroll-snap-align: center;
}
section h2 {
  text-transform: none;
  font-size: 1.25rem;
  font-weight: 900;
  padding: 0.5em 1em;
  color: #1d1e22;
  background-color: rgba(244, 244, 244, 0.5);
  mix-blend-mode: none;
  border-radius: 0.25em;
  pointer-events: none;
  user-select: none;
}
section:nth-child(2) {
  background-image: url(BG1.jpg);
}
section:nth-child(3) {
  background-image: url(BG2.jpg);
}
section:nth-child(4) {
  background-image: url(BG3.jpg);
}