style.css

:root {
  --primary-color: #475585;
  --background: #f5f5f5;
}

body {
  width: 100vw;
  height: 100vh;
  display: flex;
  flex-direction: column;
  background-color: var(--background);
  font-size: 12px;
}

header {
  position: fixed;
  display: flex;
  width: 100vw;
  height: 10vh;
  background-color: var(--background);
  z-index: 1;
}

header img#header-img {
  width: 50px;
  height: auto;
  align-self: center;
  margin: 0 15px 0 40px;
}

header h1 {
  font-family: Ubuntu, sans-serif;
  font-size: 2rem;
  font-weight: 400;
  align-self: center;
  color: var(--primary-color);
}

header nav#nav-bar {
  width: 45vw;
  height: 10vh;
  position: absolute;
  right: 0;
  display: flex;
  justify-content: space-around;
  align-items: center;
  padding: 0;
}

header nav a.nav-link {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 180px;
  height: 40px;
  margin: 0;
  text-decoration: none;
  font-family: Poppins, sans-serif;
  font-size: 1.3rem;
  font-weight: 300;
  color: var(--primary-color);
}

body section#top {
  width: 100vw;
  height: 40vh;
  margin-top: 10vh;
  background-color: var(--background);
  display: flex;
  flex-direction: column;
  align-content: center;
  justify-content: center;
  align-items: center;
  text-align: center;
  font-family: Poppins, sans-serif;
}

body section#top h2 {
  color: var(--primary-color);
  font-family: Poppins, sans-serif;
  font-weight: 700;
  font-size: 1.75rem;
}

body section#top input#email {
  width: 300px;
  padding: 10px;
  margin-top: 3px;
  outline: none;
  border: 0;
}

body section#top input#submit {
  font-family: Poppins, sans-serif;
  font-size: 1.1rem;
  font-weight: 700;
  padding: 10px;
  background-color: #3fc1c9;
  color: white;
  margin: 18px 0 80px;
  margin-bottom: 80px;
  outline: none;
  border: 0;
  cursor: pointer;
  transition: 400ms;
}

body section#top input#submit:hover {
  background-color: rgba(63, 157, 201, 1);
  transform: scale(1.05);
}

body section#middle {
  width: 100vw;
  height: 80vh;
  background-color: var(--background);
  display: flex;
  flex-direction: column;
  align-self: center;
}

body section#middle .features-div {
  display: flex;
  flex-direction: row;
  justify-content: center;
  align-items: center;
  padding: 20px 0;
  margin-bottom: 20px;
  background-color: var(--background);
}

body section#middle img {
  width: 60px;
  height: auto;
  margin-right: 80px;
}

body section#middle h4 {
  color: var(--primary-color);
  font-family: Poppins, sans-serif;
  font-weight: 700;
  font-size: 1.5rem;
  margin-top: 0;
  margin-bottom: 5px;
}

body section#middle p {
  width: 650px;
  font-family: Poppins, sans-serif;
  font-size: 1.1rem;
  font-weight: 300;
  margin: 0;
}

body section#middle div.video {
  background-color: #aaa;
  display: flex;
  justify-content: center;
  align-self: center;
  margin-top: 10%;
}

body section#bottom {
  width: 100vw;
  height: 55vh;
  margin-top: 100px;
  background-color: var(--background);
  align-self: center;
  align-content: center;
  justify-content: center;
  display: flex;
  flex-direction: grid;
  grid-template-columns: 1fr 1fr 1fr;
}

body section#bottom div.items-container {
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  width: 20vw;
  margin: 10px;
  margin-top: 80px;
  border: 1px solid black;
  background-color: (--brackground);
  border-radius: 3px;
  z-index: 1;
}

body section#bottom div.items-container div:nth-child(1) {
  width: 100%;
  background-color: #ddd;
  font-family: Poppins;
  font-weight: 300;
}

body section#bottom div.items-container div:nth-child(2) {
  font-weight: 400;
  font-family: Poppins;
  font-size: 1.8rem;
}

figure {
  margin-top: 30px;
  width: 100%;
  text-align: left;
}

figure img {
  width: 180px;
  height: 250px;
}

body section#bottom div.items-container div:nth-child(3) button {
  font-weight: 700;
  font-family: Poppins;
  font-size: 1.5rem;
  padding: 10px;
  width: 180px;
  background-color: #FFC300;
  border: 2px solid #FFC300;
  text-decoration: none;
  cursor: pointer;
  transition: 500ms;
}

body section#bottom div.items-container div:nth-child(3) button:hover {
  background-color: #E49B23;
  transform: scale(1.05);
  border: 2px solid black;
}

@media (max-width: 680px) {
  header#header nav#nav-bar {
    display: none;
  }
  header#header {
    display: flex;
    justify-content: center;
  }
  body section#middle .features-div {
    flex-direction: column;
  }
  body section#middle h4,
  body section#middle p {
    width: 80vw;
    text-align: center;
  }
  body section#middle div.features-div div.image {
    position: relative;
    left: 40px;
  }
  body section#middle div.video {
    width: 80vw;
  }
}