// Contact --------------------------------------------------------------------

.contact {
  .container;

  form {
    background: red;
    .column(7);
  }

  // Contact items list
  aside {
    .column(5);
    font-size: 24px;
    font-weight: 300;

    p {
      margin: 0;
      color: @grayDark;
    }

    ul { padding-left: 0; }

    li {
      background-image: url("@{imgPath}/about/sprite.png");
      background-repeat: no-repeat;
      color: @link;
      font-size: 18px;
      list-style: none;
      margin: 15px 0;
      margin-left: 10px;
      padding-left: 40px;
    }

    // Icons
    .email      { background-position: -680px -102px; }
    .twitter    { background-position: -679px -138px; }
    .telephone  { background-position: -680px -178px; }
    .address    { background-position: -679px -221px; }
  }
}

// Contact --------------------------------------------------------------------

.contact {
  .container;

  form {
    background: red;
    .column(7);
  }

  // Contact items list
  aside {
    .column(5);
    font-size: 24px;
    font-weight: 300;

    p {
      margin: 0;
      color: @grayDark;
    }

    ul { padding-left: 15px; }

    li {
      background-image: url("@{imgPath}/about/sprite.png");
      background-repeat: no-repeat;
      color: @link;
      font-size: 18px;
      list-style: none;
      margin: 15px 0;
      padding-left: 40px;
    }

    // Icons
    .email      { background-position: -680px -102px; }
    .twitter    { background-position: -679px -138px; }
    .telephone  { background-position: -680px -178px; }
    .address    { background-position: -679px -221px; }
  }
}

Use padding on parent element instead of on children
Use padding on parent element instead of on children
