app.scss

.App {
  min-height: 100vh;

  &:after {
    content: '';
    transition: opacity 450ms cubic-bezier(0.23, 1, 0.32, 1),
                transform 0ms cubic-bezier(0.23, 1, 0.32, 1) 450ms;
    position: fixed; top: 0; right: 0; bottom: 0; left: 0;
    background-color: rgba(0, 0, 0, 0.33);
    transform: translateX(-100%);
    opacity: 0;
    z-index: 1;
  }

  &.overlay {

    &:after {
      transition: opacity 450ms cubic-bezier(0.23, 1, 0.32, 1);
      transform: translateX(0%);
      opacity: 1;
    }
  }

  > header {
    display: flex; align-items: center;
    height: 60px;
    background-color: dodgerblue;
    color: white;
    box-shadow: 0 4px 5px 0 rgba(15, 74, 133, 0.14),
                0 2px 9px 1px rgba(15, 74, 133, 0.12),
                0 4px 2px -2px rgba(15, 74, 133, 0.2);

    > a {
      display: flex; align-items: center;
      width: 32px;
      height: 100%;
      padding: 0 10px;
      cursor: pointer;

      > svg {
        width: 100%;
        height: 100%;
  
        path {
          fill: white;
        }
      }
    }

    > h1 {
      font-size: 26px;
      line-height: 26px;
      margin-left: 10px;
    }
  }

  > nav {
    transition: transform 450ms cubic-bezier(0.23, 1, 0.32, 1);
    position: absolute; top: 0; left: 0;
    transform: translateX(calc(-100% - 10px));
    height: 100vh;
    background-color: white;
    box-shadow: rgba(0, 0, 0, 0.16) 0px 3px 10px,
                rgba(0, 0, 0, 0.23) 0px 3px 10px;
    overflow: auto;
    z-index: 2;
    backface-visibility: hidden;

    &.active {
      transform: translateX(0%);
    }

    > header {
      position: relative;
      background-color: lavender;
      height: 150px;
      margin: 0;

      > a {
        font-size: 24px;
        line-height: 24px;
        position: absolute; top: 0; left: 0;
        display: flex; align-items: center;
        height: 40px;
        padding: 10px 20px;

        > svg {
          width: 20px;
          height: 20px;
          margin-right: 20px;
        }
      }

      > svg {
        position: absolute; bottom: 45px; right: 20px;
        width: 40px;
        height: 40px;
      }

      > p {
        position: absolute; right: 20px;
        margin: 0;

        &:first-of-type {
          font-size: 18px;
          line-height: 18px;
          bottom: 25px;
        }

        &:last-of-type {
          font-size: 14px;
          line-height: 14px;
          bottom: 10px;
        }
      }
    }

    > label {
      font-weight: normal;
      font-size: 12px;
      line-height: 24px;
      text-transform: uppercase;
      display: block;
      background-color: rgba(0, 0, 0, 0.32);
      color: white;
      padding: 0 15px;
    }

    > ul {
      margin: 0;
      padding: 0;
      list-style: none;

      > li {
        position: relative;
        border-bottom: 1px solid rgba(0, 0, 0, 0.06);

        &:after {
          content: url(./img/icon/arrow-right.svg);
          position: absolute; top: 0; right: 15px; bottom: 0;
          margin: auto;
          width: 15px;
          height: 15px;
        }

        > a {
          font-size: 18px;
          line-height: 54px;
          display: block;
          padding: 0 15px;
        }

        > img {
          width: 15px;
          height: 15px;
        }
      }
    }

    @media only screen and (max-width: 767px) {
      width: 85vw;
    }

    @media only screen and (min-width: 768px) {
      width: 300px;
    }
  }

  > main {
    padding: 15px;
  }
}