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

html,
body {
  width: 100%;
  height: 100%;
  font-family: 'Roboto', sans-serif;
}

section {
  position: relative;
  display: flex;
  justify-content: center;
  align-items: center;
  width: 100%;
  min-height: 100vh;
}

section .hero-img,
section .about-img,
section .services-img {
  height: 200vh;
}

.hero {
  background-color: #06d6a0;
}

.about {
  background-color: #3f37c9;
}

.services {
  background-color: #ffc300;
}

img {
  position: absolute;
  width: 100%;
  height: 100%;
  object-fit: cover;
  z-index: -1;
}

h1 {
  color: #000;
  font-size: 12vw;
  font-weight: 600;
  letter-spacing: -0.025em;
  opacity: 0.5;
}

.blocks-container {
  position: absolute;
  width: 100%;
  height: 400px;
}

.blocks-container.top {
  top: 0;
}

.blocks-container.bottom {
  bottom: 0;
}

.blocks-row {
  display: flex;
  width: 100%;
  height: 100px;
  overflow: hidden;
}

.block {
  width: 100%;
  height: 100%;
  transition: opacity 100ms;
}

.blocks-container.top .blocks-row .block {
  opacity: 1;
}

.blocks-container.bottom .blocks-row .block {
  opacity: 0;
}

.hero-img .blocks-container.top .blocks-row .block {
  background-color: #06d6a0;
}

.hero-img .blocks-container.bottom .blocks-row .block {
  background-color: #3f37c9;
}

.about-img .blocks-container.top .blocks-row .block {
  background-color: #3f37c9;
}

.about-img .blocks-container.bottom .blocks-row .block {
  background-color: #ffc300;
}

.services-img .blocks-container.top .blocks-row .block {
  background-color: #ffc300;
}

.services-img .blocks-container.bottom .blocks-row .block {
  background-color: #1b263b;
}

footer {
  display: flex;
  justify-content: center;
  align-items: center;
  width: 100%;
  height: 50px;
  background-color: #1b263b;
}

footer .copyright {
  color: #fff;
  font-size: 14px;
}