font

font:
  1.2rem "Fira Sans",
  sans-serif;

font:
  italic 1.2rem "Fira Sans",
  serif;

font: italic small-caps bold 16px/2 cursive;

font: small-caps bold 24px/1 sans-serif;

font: caption;

<section id="default-example">
  <p id="example-element">
    London. Michaelmas term lately over, and the Lord Chancellor sitting in
    Lincoln's Inn Hall. Implacable November weather. As much mud in the streets
    as if the waters had but newly retired from the face of the earth, and it
    would not be wonderful to meet a Megalosaurus, forty feet long or so,
    waddling like an elephantine lizard up Holborn Hill.
  </p>
</section>

@font-face {
  font-family: "Fira Sans";
  src:
    local("FiraSans-Regular"),
    url("/shared-assets/fonts/FiraSans-Regular.woff2") format("woff2");
  font-weight: normal;
  font-style: normal;
}

@font-face {
  font-family: "Fira Sans";
  src:
    local("FiraSans-Italic"),
    url("/shared-assets/fonts/FiraSans-Italic.woff2") format("woff2");
  font-weight: normal;
  font-style: italic;
}

section {
  margin-top: 10px;
  font-size: 1.1em;
}

/* font-size font-family */
font: 1.2em "Fira Sans", sans-serif;

/* font-size/line-height font-family */
font: 1.2em/2 "Fira Sans", sans-serif;

/* font-style font-weight font-size font-family */
font: italic bold 1.2em "Fira Sans", sans-serif;

/* font-stretch font-variant font-size font-family */
font: ultra-condensed small-caps 1.2em "Fira Sans", sans-serif;

/* システムフォント */
font: caption;

/* フォントの大きさを 12px に設定し、行の高さを 14px にする。
   フォントファミリは sans-serif に設定する */
p {
  font: 12px/14px sans-serif;
}

/* フォントの大きさを親要素の 80% または既定値
   (親要素がない場合) に設定する。
   フォントファミリは sans-serif に設定する */
p {
  font: 80% sans-serif;
}

/* フォントの太さを太字に、
   フォントスタイルを斜体に、
   フォントの大きさを large に、
   フォントファミリーは serif に設定する */
p {
  font: bold italic large serif;
}

/* ウィンドウのステータスバーと同じフォントに設定する */
p {
  font: status-bar;
}

<p>
  下のラジオボタンを変更すると、生成された一括指定とその効果が確認できます。
</p>
<form action="createShortHand()">
  <div class="cf">
    <div class="setPropCont">
      font-style<br />
      <input
        type="radio"
        id="font-style-none"
        name="font_style"
        checked=""
        value=""
        onchange="setCss()" />
      <label for="font-style-none">none</label><br />
      <input
        type="radio"
        id="font-style-normal"
        name="font_style"
        value="normal"
        onchange="setCss()" />
      <label for="font-style-normal">normal</label><br />
      <input
        type="radio"
        id="font-style-italic"
        name="font_style"
        value="italic"
        onchange="setCss()" />
      <label for="font-style-italic">italic</label><br />
      <input
        type="radio"
        id="font-style-oblique"
        name="font_style"
        value="oblique"
        onchange="setCss()" />
      <label for="font-style-oblique">oblique</label>
    </div>

    <div class="setPropCont">
      font-variant<br />
      <input
        type="radio"
        id="font-variant-none"
        name="font_variant"
        checked=""
        value=" "
        onchange="setCss()" />
      <label for="font-variant-none">none</label><br />
      <input
        type="radio"
        id="font-variant-normal"
        name="font_variant"
        value="normal"
        onchange="setCss()" />
      <label for="font-variant-normal">normal</label><br />
      <input
        type="radio"
        id="font-variant-small-caps"
        name="font_variant"
        value="small-caps"
        onchange="setCss()" />
      <label for="font-variant-small-caps">small-caps</label>
    </div>

    <div class="setPropCont">
      font-weight<br />
      <input
        type="radio"
        id="font-weight-none"
        name="font_weight"
        value=""
        onchange="setCss()" />
      <label for="font-weight-none">none</label><br />
      <input
        type="radio"
        id="font-weight-normal"
        checked=""
        name="font_weight"
        value="400"
        onchange="setCss()" />
      <label for="font-weight-normal">normal</label><br />
      <input
        type="radio"
        id="font-weight-bold"
        name="font_weight"
        value="700"
        onchange="setCss()" />
      <label for="font-weight-bold">bold</label>
    </div>

    <div class="setPropCont">
      font-size<br />
      <input
        type="radio"
        id="font-size-12px"
        name="font_size"
        value="12px"
        onchange="setCss()" />
      <label for="font-size-12px">12px</label><br />
      <input
        type="radio"
        id="font-size-16px"
        name="font_size"
        value="16px"
        checked=""
        onchange="setCss()" />
      <label for="font-size-16px">16px</label><br />
      <input
        type="radio"
        id="font-size-24px"
        name="font_size"
        value="24px"
        onchange="setCss()" />
      <label for="font-size-24px">24px</label>
    </div>

    <div class="setPropCont">
      line-height<br />
      <input
        type="radio"
        id="line-height-none"
        name="line_height"
        checked=""
        value=""
        onchange="setCss()" />
      <label for="line-height-none">none</label><br />
      <input
        type="radio"
        id="line-height-1.2"
        name="line_height"
        value="/1.2"
        onchange="setCss()" />
      <label for="line-height-1.2">1.2</label><br />
      <input
        type="radio"
        id="line-height-3"
        name="line_height"
        value="/3"
        onchange="setCss()" />
      <label for="line-height-3">3</label>
    </div>
    <br />

    <div class="setPropCont fontfamily">
      font-family<br />
      <input
        type="radio"
        id="font-family-courier"
        name="font_family"
        checked=""
        value="courier"
        onchange="setCss(5,'courier')" />
      <label for="font-family-courier">courier</label><br />
      <input
        type="radio"
        id="font-family-serif"
        name="font_family"
        value="serif"
        onchange="setCss()" />
      <label for="font-family-serif">serif</label><br />
      <input
        type="radio"
        id="font-family-sans-serif"
        name="font_family"
        value="sans-serif"
        onchange="setCss()" />
      <label for="font-family-sans-serif">sans-serif</label><br />
      <input
        type="radio"
        id="font-family-arial"
        name="font_family"
        value="arial"
        onchange="setCss()" />
      <label for="font-family-arial">Arial</label><br />
      <input
        type="radio"
        id="font-family-monospace"
        name="font_family"
        value="monospace"
        onchange="setCss()" />
      <label for="font-family-monospace">monospace</label><br />
      <input
        type="radio"
        id="font-family-cursive"
        name="font_family"
        value="cursive"
        onchange="setCss()" />
      <label for="font-family-cursive">cursive</label><br />
      <input
        type="radio"
        id="font-family-fantasy"
        name="font_family"
        value="fantasy"
        onchange="setCss()" />
      <label for="font-family-fantasy">fantasy</label><br />
      <input
        type="radio"
        id="font-family-system-ui"
        name="font_family"
        value="system-ui"
        onchange="setCss()" />
      <label for="font-family-system-ui">system-ui</label><br />
    </div>
  </div>

  <div class="cf propInputs">
    <div class="propInputCont tar">font :</div>
    <div class="propInputCont">
      <input type="text" class="curCss" id="input_font_style" /><br />
      font-style <br />
      optional
    </div>
    <div class="propInputCont">
      <input type="text" class="curCss" id="input_font_variant" /> <br />
      font-variant <br />
      optional
    </div>
    <div class="propInputCont">
      <input type="text" class="curCss" id="input_font_weight" /> <br />
      font-weight <br />
      optional
    </div>
    <div class="propInputCont">
      <input type="text" class="curCss mandatory" id="input_font_size" /> <br />
      font-size <br />
      mandatory
    </div>
    <div class="propInputCont">
      <input type="text" class="curCss" id="input_line_height" /> <br />
      line-height <br />
      optional
    </div>
    <div class="propInputCont">
      <input type="text" class="curCss mandatory" id="input_font_family" />
      <br />
      font-family <br />
      mandatory
    </div>
  </div>
</form>

<div class="fontShortHand">This is some sample text.</div>
<br /><br /><br /><br /><br /><br />

body,
input {
  font: 14px arial;
  overflow: hidden;
}

.propInputCont {
  float: left;
  text-align: center;
  margin-right: 5px;
  width: 80px;
}

.setPropCont {
  float: left;
  margin-right: 5px;
  width: 120px;
}

.propInputs,
.setPropCont {
  margin-bottom: 1em;
}

.curCss {
  border: none;
  border-bottom: 1px solid black;
  text-align: center;
  width: 80px;
}

.mandatory {
  border-bottom-color: red;
}

.cf::before,
.cf::after {
  content: " ";
  display: table;
}

.cf::after {
  clear: both;
}

.tar {
  width: 40px;
  text-align: right;
}
.fontfamily {
  display: inline-block;
}

const textAreas = document.getElementsByClassName("curCss");

function getProperties() {
  return (
    `${getCheckedValue("font_style")} ` +
    `${getCheckedValue("font_variant")} ` +
    `${getCheckedValue("font_weight")} ` +
    `${getCheckedValue("font_size")}` +
    `${getCheckedValue("line_height")} ` +
    `${getCheckedValue("font_family")}`
  );
}

function getCheckedValue(radioName) {
  const radios = document.forms[0].elements[radioName];
  for (let i = 0; i < radios.length; i++) {
    if (radios[i].checked) {
      const curElemName = `input_${radioName}`;
      const curElem = document.getElementById(curElemName);
      curElem.value = radios[i].value;

      return radios[i].value;
    }
  }
}

function setCss() {
  injectCss(getProperties());
}

function injectCss(cssFragment) {
  const old = document.body.getElementsByTagName("style");
  if (old.length > 1) {
    old[1].parentElement.removeChild(old[1]);
  }
  css = document.createElement("style");
  css.textContent = `.fontShortHand{font: ${cssFragment}}`;
  document.body.appendChild(css);
}

setCss();