doc/themes/quark/scss/theme/_framework.scss

html {
  height: 100%;
}

#body-wrapper {
  .container {
    padding: $vert-padding;
  }

  // Fixed Header solution
  .header-fixed & {
    padding-top: $header-height-large;
  }
}

.header-fixed {
  .hero + #start > #body-wrapper {
    padding-top: 0;
  }
}

section.section {
  padding-left: $horiz-padding;
  padding-right: $horiz-padding;
  position: relative;
}

.overlay-light, .overlay-dark, .overlay-light-gradient, .overlay-dark-gradient {
  z-index: 0;
}

// Hero
.hero {
  display: flex;
  align-items: center;
  justify-content: center;

  padding-top: 6rem;
  padding-bottom: 7rem;
  background-size: cover;
  background-position: center;

  h1 {
    color: $header-text-dark;
    font-size: 4rem;
  }

  h2 {
    color: rgba($header-text-dark, 0.8);
    font-size: 2.5rem;
  }

  &.hero-fullscreen {
    min-height: 100vh;
  }

  &.hero-large {
    min-height: 500px;
  }

  &.hero-medium {
    min-height: 400px;
  }

  &.hero-small {
    min-height: 110px;
  }

  &.hero-tiny {
    min-height: 8rem;
  }
  
  .header-fixed & {
    background-position: 50% 0;
  }

  //&.parallax {
  //  background-attachment: fixed;
  //}

  @include breakpoint(md) {
    h1 {
      font-size: 3rem;
    }
    h2 {
      font-size: 1.75rem;
    }
  }

  @include breakpoint(sm) {
    h1 {
      font-size: 2rem;
    }
    h2 {
      font-size: 1.25rem;
    }
  }


  &.text-light {
    h1 {
      color: $header-text-light;
    }
    h2 {
      color: rgba($header-text-light, 0.8);
    }
  }

  p {
    font-size: .9rem;
    font-weight: 300;
  }

  #to-start {
    display: inline-block;
    position: absolute;
    bottom: 10px;
    font-size: 2rem;
    cursor: pointer;
  }
}

// Overlay
.image-overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  z-index: -1;

  .overlay-light & {
    background: rgba(#fff, 0.4);
  }

  .overlay-light-gradient & {
    background: linear-gradient(to bottom, rgba(#fff,0.5), rgba(#fff,0.2));
  }

  .overlay-dark & {
    background: rgba(#000, 0.4);
  }

  .overlay-dark-gradient & {
    background: linear-gradient(to bottom, rgba(#000,0.5), rgba(#000,0.2));
  }
}