main {
  margin: 0.2rem;
}

a {
  text-decoration: none;
}

#main-content {
  display: block;
  /* other style */
}

#main-content #ads-left,
#main-content #ads-right,
#main-content #contents {
  /* border: 1px solid rgb(194, 20, 20); */
  min-height: 600px;
  min-width: 200px;
}

#main-content #contents {
  padding: 0.5rem;
  width: 100%;
}

#main-content #ads-left,
#main-content #ads-right,
#main-content #contents {
  position: relative;
}

@media all and (max-width: 1024px) {
  /* disable on mobile */
  #ads-left,
  #ads-right {
    display: none;
  }
}

@media all and (min-width: 1025px) {
  #main-content {
    /* big landscape tablets, laptops, and desktops */
    display: grid;
    grid-template-columns: 15% 70% 15%;
    grid-gap: 2px;
    grid-auto-flow: row dense;
    /* grid setting */
    /* position */
  }
  #main-content #ads-left {
    grid-column: 1;
    grid-row: 1;
  }
  #main-content #ads-right {
    grid-column: 3;
    grid-row: 1;
  }
  #main-content #contents {
    grid-column: 2;
    grid-row: 1;
  }
  #main-content #ads-left,
  #main-content #ads-right {
    position: fixed;
    height: 100%;
  }
  #main-content #ads-right {
    right: 0px;
  }
  #main-content #ads-left {
    left: 0px;
  }
}

/* footer */
footer {
  padding-top: 40px;
  padding-bottom: 40px;
  margin-top: 40px;
}

footer * {
  text-align: center;
}