frontend/src/styles/_base.scss

* {
  padding: 0;
  margin: 0;
  box-sizing: border-box;
}

:root {
  --color-text: #333;
  --color-background: #fff;
  --color-primary: #3f51b5;
  --color-primary-text: #fff;
  --drop-shadow: drop-shadow(0 10px 10px rgb(0, 0, 0, 0.2));
  --dropdown-arrow: url("data:image/svg+xml;utf8,%3Csvg%20xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F2000%2Fsvg%22%20width%3D%2225%22%20height%3D%2210%22%3E%3Cpath%20fill%3D%22%23333%22%20fill-opacity%3D%221%22%20stroke%3D%22none%22%20d%3D%22M0%2C0%20L0%2C0%20L1%2C0%20L1%2C6%20L7%2C6%20L7%2C7%20L0%2C7%20z%22%20transform%3D%22rotate(-45%205%200)%22%20%2F%3E%3C%2Fsvg%3E");
  --pin-width: 32px;
}

html, body {
  height: 100%;
}

body {
  font-family: "Noto Sans", sans-serif;
  font-size: 14px;
  color: var(--color-text);
}

a {
  color: var(--color-primary);
}

ul {
  list-style: inside;
}

input[type="checkbox"] {
  appearance: none;
  border: 0; // Remove the unchecked checkbox outline in Safari on iOS
  border-radius: 4px; // Round the focus box-shadow
  cursor: pointer;
  margin-right: 3px;
  position: relative;
  vertical-align: top;

  &:focus {
    outline: none;
    box-shadow: 0 0 0 3px rgba(0, 0, 0, 0.2);
  }

  &::before {
    border: 2px solid var(--color-primary);
    border-radius: 4px;
    content: "";
    display: block;
    height: 16px;
    width: 16px;
  }

  &:checked::before {
    background: var(--color-primary);
  }

  &:checked::after {
    border-bottom: 2px solid var(--color-primary-text);
    border-right: 2px solid var(--color-primary-text);
    content: "";
    display: inline-block;
    height: 10px;
    left: 7px;
    position: absolute;
    top: 3px;
    transform: rotate(45deg);
    width: 4px;
  }

  & + label {
    cursor: pointer;
  }
}

pre {
  background: #000;
  border-radius: 3px;
  color: #ddd;
  display: block;
  font-family: Consolas, "Andale Mono WT", "Andale Mono", "Lucida Console",
    "Lucida Sans Typewriter", "DejaVu Sans Mono", "Bitstream Vera Sans Mono",
    "Liberation Mono", "Nimbus Mono L", Monaco, "Courier New", Courier, monospace;
  overflow-x: auto;

  code {
    display: block;
    margin: 20px;
  }
}

#app {
  display: flex;
  min-height: 100%;
  flex-direction: column;

  // Only select immediate child as the datepicker contains a <header> as well
  > header {
    display: flex;
    padding: 20px;
    white-space: nowrap;
    color: var(--color-primary-text);
    background: var(--color-primary);

    nav {
      display: flex;
      flex: 1;
      align-items: center;

      &:not(:first-child) {
        margin-left: 20px;
      }

      &.nav-shrink {
        flex: 0 1 auto;
      }

      .nav-item:not(:first-child) {
        margin-left: 20px;
      }

      .feather {
        font-size: 20px;
        margin-right: 10px;
      }

      .button-icon .feather {
        margin: 0;
      }
    }
  }

  main {
    flex: 1;
    position: relative;
  }

  ul.info-list {
    list-style: none;

    li {
      // https://stackoverflow.com/a/17158366/5952681
      margin-left: 25px;
      text-indent: -25px;

      .feather {
        font-size: 16px;
        margin-right: 8px;
      }

      a {
        font-weight: bold;
        text-decoration: none;
      }

      & + li {
        margin-top: 15px;
      }
    }
  }
}

.button {
  cursor: pointer;
  color: var(--color-text);
  background: var(--color-background);
  border: 0;
  border-radius: 18px;
  overflow: hidden;
  padding: 8px 16px;
  text-overflow: ellipsis;
  white-space: nowrap;
  transition: box-shadow 0.2s;

  &:focus {
    outline: none;
    box-shadow: 0 0 0 5px rgba(0, 0, 0, 0.2);
  }

  &:focus::-moz-focus-inner {
    border-color: transparent;
  }

  &.button-primary {
    color: var(--color-primary-text);
    background: var(--color-primary);
  }

  &.button-outline {
    border: 1px solid var(--color-background);
    color: var(--color-primary-text);
    background: transparent;

    &.button-primary {
      border-color: var(--color-primary);
      color: var(--color-text);
    }
  }

  &.button-flat {
    color: var(--color-primary-text);
    background: transparent;

    &.button-primary {
      color: var(--color-text);
    }
  }

  &.button-outline,
  &.button-flat {
    transition: background-color 0.2s, box-shadow 0.2s;

    &:hover,
    &:focus {
      background: rgba(0, 0, 0, 0.2);
    }
  }

  &.button-icon {
    padding: 8px;
  }
}

.dropdown {
  display: inline-block;
  position: relative;
}

// Not nested so it works as the button alone
.dropdown-button {
  appearance: none;
  background-image: var(--dropdown-arrow);
  background-repeat: no-repeat;
  background-position-x: right;
  background-position-y: center;
  padding-right: 30px;
}

.dropdown-body {
  position: absolute;
  margin-top: 12px;
  padding: 8px 0;
  border-radius: 3px;
  color: var(--color-text);
  background: var(--color-background);
  filter: var(--drop-shadow);
  z-index: 1;

  &::before {
    content: "";
    border-left: 10px solid transparent;
    border-right: 10px solid transparent;
    border-top: 10px solid transparent;
    border-bottom: 10px solid var(--color-background);
    position: absolute;
    top: -20px;
    left: 20px;
  }

  label {
    cursor: pointer;
    display: block;
    padding: 8px 15px;

    &:hover {
      background: rgba(0, 0, 0, 0.2);
    }
  }
}

.feather {
  vertical-align: middle;
}