JSFiddle - React, Tailwind, and code Playground

by Fleuv

HTML

<section class="dark">
  <h1>Custom</h1>
  <div class="input-decorator">
    <div class="input-label">
      <label for="foo">Ik wil melk</label>
    </div>
    <div class="input-control">
      <input id="foo" placeholder="Moooo!" />
    </div>
  </div>

  <h1>Fieldset</h1>
  <fieldset>
    <legend>
      <label for="fs-foo">Ik wil melk</label>
    </legend>
    <input id="fs-foo" placeholder="Moooo!" />
  </fieldset>
</section>

<section>
  <h1>Custom</h1>
  <div class="input-decorator">
    <div class="input-label">
      <label for="bar">Ik wil kaas</label>
    </div>
    <div class="input-control">
      <input id="bar" placeholder="Moooo?" />
    </div>
  </div>

  <h1>Fieldset</h1>
  <fieldset>
    <legend>
      <label for="fs-bar">Ik wil kaas</label>
    </legend>
    <input id="fs-bar" placeholder="Moooo?" />
  </fieldset>
</section>

CSS

.input-decorator {

  border-radius: var(--input--border-radius, 4px);
}

.input-label {
  display: flex;
  height: var(--input-label--height, 18px);
}

.input-label::before,
.input-label::after {
  content: '';
  display: inline-block;
  height: calc(var(--input-label--height, 18px) / 2);
  border-top: 1px solid var(--input--border-color, black);
  margin-top: calc((var(--input-label--height, 18px) / 2));
}

.input-label::before {
  min-width: 0.75rem;
  margin-right: 0.5rem;
  border-top-left-radius: var(--input--border-radius, 4px);
}

.input-label::after {
  flex: 1 1 auto;
  min-width: 1rem;
  margin-left: 0.5rem;
  border-top-right-radius: var(--input--border-radius, 4px);
}

.input-control {
  padding: 1px 0;
  border-width: 0 1px 1px;
  border-style: solid;
  border-color: var(--input--border-color, black);
  border-radius: var(--input--border-radius, 4px);
  margin-top: calc(-1 * var(--input-label--height, 18px) / 2);
  background: var(--input-control--background, white);
}

.input-control input {
  padding: 0.5rem 0.75rem;
}


/** fieldset + legend */

fieldset {
  margin: 0;
  padding: 0 0.75rem 0.5rem;
  background: var(--input-control--background, white);
  border: 1px solid var(--fieldset--border-color, black);
  border-radius: var(--fieldset--border-radius, 4px);
}

fieldset legend {
  padding: 0 0.5rem;
}

fieldset input {
  padding: 0;
}

/** unrelated */
body,
html {
  margin: 0;
  font-size: 14px;
  font-family: sans-serif;
}

section {
  padding: 2rem;
}

input {
  outline: none;
  width: 100%;
  margin: 0;
  border: 0;
  font-size: 13px;
  background-color: transparent;
}

.dark {
  background-color: rgba(0, 0, 0, 0.1);
}