CSS 段組みレイアウト

<article>
  <div class="title">
    <h1>A Lament for Confederation</h1>
    <p>&mdash;Chief Dan George, 1967</p>
  </div>
  <p>
    How long have I known you, Oh Canada? A hundred years? Yes, a hundred years.
    And many, many tides more. And today, when you celebrate your hundred years,
    Oh Canada, I am sad for all the Indian people throughout the land.
  </p>
  <p>
    For I have known you when your forests were mine; when they gave me my meat
    and my clothing. I have known you in your fruits and rivers where your fish
    flashed and danced in the sun, where the waters said ‘come and eat of my
    abundance.’ I have known you in the freedom of your winds. And my spirit,
    like your winds, once roamed this good lands.
  </p>
  <blockquote>
    <p>
      But in long the hundred years since the white man came, I have seen that
      freedom disappear just like the salmon going mysteriously out to sea.
    </p>
  </blockquote>
  <p>
    The white man’s strange customs I could not understand, pressed down upon me
    until I could no longer breathe.
  </p>
  <p>
    When I fought to protect my home and my land, I was called a savage. When I
    neither understood nor welcomed this new way of life, I was called lazy.
    When I tried to rule my people, I was stripped of my authority.
  </p>
  <p>
    My nation was ignored in your history textbooks – we were less important in
    the history of Canada than the buffalo that ranged the plains. I was
    ridiculed in your plays and motion pictures, and when I drank your
    fire-water, I got drunk – very, very drunk. And I forgot.
  </p>
  <p>
    Oh Canada, how can I celebrate with you this centenary, this hundred years?
    Shall I thank you for the reserves that are left me of my beautiful forests?
    Shall I thank you for the canned fish of my rivers? Shall I thank you for
    the loss of my pride and authority, even among my own people? For the lack
    of my will to fight back? No! I must forget what is past and gone.
  </p>
  <p>
    Oh God in heaven! Give me the courage of the olden chiefs. Let me wrestle
    with my surroundings. Let me once again, as in the days of old, dominate my
    environment. Let me humbly accept this new culture and through it rise up
    and go on.
  </p>
  <p>
    Oh god, like the thunderbird of old, I shall rise again out of the sea. I
    shall grab the instruments of the white man’s success – his education, his
    skills, and with these new tools I shall build my race into the proudest
    segment of your society. And, before I follow the great chiefs who have gone
    before us, I shall see these things come to pass.
  </p>
  <p>
    I shall see our young braves and our chiefs sitting in the house of law and
    government, ruling and being ruled by the knowledge and freedoms of our
    great land. So shall we shatter the barriers of our isolation. So shall the
    next hundred years be the greatest in the proud history of our tribes and
    nations.
  </p>
</article>
<fieldset id="options" class="open">
  <legend>
    <button aria-expanded="true" aria-controls="controls">
      段のオプション
    </button>
  </legend>
  <div id="controls">
    <p>
      <input type="range" min="0" max="5" value="5" id="colCount" />
      <label for="colCount">段の最大数</label>
    </p>
    <p>
      <input type="range" min="2" max="40" value="10" step="2" id="colWidth" />
      <label for="colWidth">段の最小幅</label>
    </p>
    <p>
      <input type="range" min="0" max="10" value="1" step="0.5" id="gapSize" />
      <label for="gapSize">段間</label>
    </p>
    <p>
      <input type="checkbox" checked id="colSpan" />
      <label for="colSpan">署名欄をすべての段にまたがらせる</label>
    </p>
    <p>
      <input type="checkbox" id="blockSpan" />
      <label for="blockSpan">引用をすべての段にまたがらせる</label>
    </p>
    <p>
      <input type="checkbox" id="colFill" />
      <label for="colFill">段のバランスをとる</label>
    </p>
    <p>
      <input type="checkbox" id="break" />
      <label for="break">段落を分割しない</label>
    </p>
  </div>
</fieldset>

const page = document.querySelector("article");
const title = document.querySelector(".title");
const options = document.querySelector("#options");
const legend = document.querySelector("#options > legend");
const legendBtn = document.querySelector("#options > legend > button");
const blockquote = document.getElementsByTagName("blockquote")[0];

const colCount = document.getElementById("colCount");
const colWidth = document.getElementById("colWidth");
const gapSize = document.getElementById("gapSize");
const colSpan = document.getElementById("colSpan");
const blockSpan = document.getElementById("blockSpan");
const colFill = document.getElementById("colFill");
const breakP = document.getElementById("break");

// JS が有効である場合にオプションが見えるようにする
options.style.display = "revert";

legendBtn.addEventListener("click", () => {
  showAndHideMenu();
});

colCount.addEventListener("change", () => {
  page.style.columnCount = colCount.value;
});

colWidth.addEventListener("change", () => {
  page.style.columnWidth = `${colWidth.value}em`;
});

gapSize.addEventListener("change", () => {
  page.style.gap = `${gapSize.value}em`;
});

colSpan.addEventListener("change", () => {
  setColSpan(colSpan, title);
});

blockSpan.addEventListener("change", () => {
  setColSpan(blockSpan, blockquote);
});

colFill.addEventListener("change", () => {
  if (colFill.checked) {
    page.style.columnFill = "balance";
  } else {
    page.style.columnFill = "auto";
  }
});

breakP.addEventListener("change", () => {
  if (breakP.checked) {
    page.classList.add("breakInside");
  } else {
    page.classList.remove("breakInside");
  }
});

function showAndHideMenu() {
  if (legendBtn.getAttribute("aria-expanded") === "true") {
    // close it
    legendBtn.setAttribute("aria-expanded", "false");
    legend.classList.add("closed");
    legend.classList.remove("open");
  } else {
    // open it
    legendBtn.setAttribute("aria-expanded", "true");
    legend.classList.remove("closed");
    legend.classList.add("open");
  }
}

function setColSpan(control, element) {
  if (control.checked) {
    element.style.columnSpan = "all";
  } else {
    element.style.columnSpan = "none";
  }
}

article {
  column-count: 5;
  column-width: 8em;
  widows: 3;
  orphans: 3;
  gap: 1em;
  column-rule: 2px dashed #666666;
  height: 50em;
}
.title {
  column-span: all;
  display: flex;
  align-items: baseline;
  gap: 1em;
  flex-wrap: wrap;
}
p {
  margin: 0 0 1em 0;
  line-height: 1.4;
}
.breakInside * {
  break-inside: avoid;
}
#options {
  position: fixed;
  top: 1rem;
  right: 1rem;
  background: white;
  display: none;
}
fieldset p {
  margin-bottom: 0.25em;
}
legend {
  position: relative;
  top: 0;
  transition: 200ms;
}
legend.closed {
  top: 0.75em;
}
legend.closed + #controls {
  display: none;
}
legend {
  background-color: #dedede;
  padding: 0.5em;
}
legend > button {
  all: unset;
  cursor: pointer;
}
legend.closed {
  margin: -1em;
  display: inline-block;
}
blockquote {
  border: 2px dashed red;
  margin: 0 0 0.25em 0;
}
blockquote p {
  margin-bottom: 0;
}
blockquote p::before,
blockquote p::after {
  content: '"';
  font-size: 1.2em;
  vertical-align: baseline;
  color: red;
}