edx-platform/sass/layout/_leanmodal.scss

#lean_overlay {
  position: fixed;
  z-index:100;
  top: 0px;
  left: 0px;
  height:100%;
  width:100%;
  background: #000;
  display: none;
}

div.leanModal_box {
  background: #fff;
  border: none;
  @include border-radius(3px);
  @include box-shadow(0 0 6px #000);
  @include box-sizing(border-box);
  display: none;
  padding: lh(2);

  a.modal_close {
    color: #aaa;
    display: block;
    font-style: normal;
    height: 14px;
    position: absolute;
    right: 12px;
    top: 12px;
    width: 14px;
    z-index: 2;

    &:hover{
      text-decoration: none;
      color: $mit-red;
    }
  }

  h1 {
    border-bottom: 1px solid #eee;
    font-size: 24px;
    margin-bottom: lh();
    margin-top: 0;
    padding-bottom: lh();
    text-align: left;
  }

  &#enroll {
    max-width: 600px;

    p.ie-warning {
      display: none;
    }

    ol {
      @extend .clearfix;
      padding-top: lh();

      li {

        &.terms, &.honor-code {
          width: auto;
          float: none;
        }

        div.tip {
          display: none;
        }

        &:hover {
          div.tip {
            background: #333;
            color: #fff;
            display: block;
            font-size: 16px;
            line-height: lh();
            margin: 0 0 0 -10px;
            padding: 10px;
            position: absolute;
            -webkit-font-smoothing: antialiased;
            width: 500px;
          }
        }
      }
    }
  }

  form {
    text-align: left;

    div#enroll_error, div#login_error, div#pwd_error {
      $error-color: #333;
      background-color: $error-color;
      border: darken($error-color, 20%);
      color: #fff;
      font-family: "Open sans";
      font-weight: bold;
      letter-spacing: 1px;
      margin: (-(lh())) (-(lh())) lh();
      padding: lh(.5);
      text-shadow: 0 1px 0 darken($error-color, 10%);
      -webkit-font-smoothing: antialiased;

      &:empty {
        padding: 0;
      }
    }

    ol {
      list-style: none;
      margin-bottom: lh();

      li {
        margin-bottom: lh(.5);

        &.terms, &.remember {
          border-top: 1px solid #eee;
          clear: both;
          float: none;
          padding-top: lh();
          width: auto;
        }

        &.honor-code {
          width: auto;
          float: none;
        }

        label {
          display: block;
          font-weight: bold;
        }

        #{$all-text-inputs}, textarea {
          width: 100%;
          @include box-sizing(border-box);
        }

        input[type="checkbox"] {
          margin-right: 10px;
        }

        ul {
          list-style: disc outside none;
          margin: lh(.5) 0 lh() lh();

          li {
            color: #666;
            float: none;
            font-size: 14px;
            list-style: disc outside none;
            margin-bottom: lh(.5);
          }
        }
      }
    }

    input[type="button"], input[type="submit"] {
      @include button($mit-red);
      font-size: 18px;
      padding: lh(.5);
    }
  }
}

div#login {
  min-width: 400px;

  header {
    border-bottom: 1px solid #ddd;
    margin-bottom: lh();
    padding-bottom: lh();

    h1 {
      border-bottom: 0;
      padding-bottom: 0;
      margin-bottom: lh(.25);
    }
  }

  ol {
    li {
      width: auto;
      float: none;
    }
  }
}

div.lost-password {
  text-align: left;
  margin-top: lh();

  a {
    color: #999;

    &:hover {
      color: #444;
    }
  }
}

div#pwd_reset {
  p {
    margin-bottom: lh();
  }

  input[type="email"] {
    margin-bottom: lh();
  }
}

div#feedback_div{
  form{
    ol {
      li {
        float: none;
        width: 100%;

        textarea#feedback_message {
          height: 100px;
        }
      }
    }
  }
}

div#calculator_div {
  max-width: 500px;

  form {
    padding-bottom: lh();
    margin-bottom: lh();
    border-bottom: 1px solid #ddd;

    input#calculator_input {
      width: 400px;
    }

    input#calculator_button {
      background: 0;
      color: $mit-red;
      border: 0;
      @include box-shadow(none);
      padding: 0;
      text-shadow: none;

      &:hover {
        color: #333;
      }
    }

    input#calculator_output {
      border: 0;
      background: none;
      padding: lh(.35);
      font-size: 24px;
      width: 378px;
      font-weight: bold;
      margin-top: 4px;
    }
  }

  dl {
    dt {
      float: left;
      clear: both;
      padding-right: lh(.5);
      font-weight: bold;
    }

    dd {
      float: left;
    }
  }
}