<div class="box"></div>

<div class="actions">
  <div class="control">
    <label for="border-radius">border-radius:</label>
    <input type="range" id="border-radius" min="0" max="100" value="50" step="1" />
    <output data-border-radius>50px</output>
  </div>
  <div class="control">
    <label for="border-width">border-width:</label>
    <input type="range" id="border-width" min="0" max="100" value="50" step="1" />
    <output data-border-width>50px</output>
  </div>
  <div class="control">
    <label for="padding">padding:</label>
    <input type="range" id="padding" min="0" max="100" value="50" step="1" />
    <output data-padding>50px</output>
  </div>

  <ul>
    <li>border</li>
    <li>padding</li>
    <li>content</li>
  </ul>
</div>

body {
  background-color: #1d1e1f;
  width: 100vw;
  min-height: 100vh;
  display: flex;
  justify-content: center;
  align-items: center;
}

:root {
  --border-radius: 50px;
  --border-width: 30px;
  --padding: 30px;
}

.box {
  margin: 5px;
  width: 480px;
  height: 480px;
  box-sizing: border-box;
  background-image: linear-gradient(134deg, #3023ae 0%, #c86dd7 100%),
    linear-gradient(134deg, #f36 0%, #f63 100%);
  background-origin: padding-box;
  background-clip: content-box, padding-box;
  border-radius: var(--border-radius);
  border: var(--border-width) solid #f90;
  padding: var(--padding);
}

.actions {
  display: flex;
  flex-direction: column;
  color: #fff;
  font-size: 1.5rem;
}

.control {
  display: flex;
  align-items: center;
  margin-bottom: 10px;
}

label {
  min-width: 200px;
  text-align: right;
  margin-right: 10px;
}

ul {
  margin: 20px 0 0;
  padding: 0;
  list-style: none outside none;
  display: flex;
  flex-direction: column;
}

li {
  display: flex;
  align-items: center;
  text-align: right;
  max-width: 200px;
  margin-bottom: 10px;
  justify-content: flex-end;
}

li::before {
  content: "";
  display: inline-block;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  margin-right: 10px;
}

li:nth-child(1)::before {
  background: #f90;
}

li:nth-child(2)::before {
  background: linear-gradient(134deg, #f36 0%, #f63 100%);
}

li:nth-child(3)::before {
  background: linear-gradient(134deg, #3023ae 0%, #c86dd7 100%);
}

output {
  margin-left: 5px;
}

const inputs = document.querySelectorAll("input");

const documentElement = document.documentElement;

inputs.forEach((item, index) => {
  item.addEventListener("change", (etv) => {
    documentElement.style.setProperty(
      `--${etv.target.id}`,
      `${etv.target.value}px`
    );
    document.querySelector(
      `output[data-${etv.target.id}]`
    ).textContent = `${etv.target.value}px`;
  });
});