/share/WebKit/css/viewport-units.html

<!DOCTYPE html>
<html>
<head>
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <style>
body {
    margin: 0;
    text-align: center;
    font-size: 15pt;
    font-family: monospace;
    background-color: lightgrey;
    height: 200vh;
}

div {
    box-sizing: border-box;
    position: absolute;
    top: 0;
    left: calc((var(--width) + 4px) * var(--index));
    width: var(--width);
    writing-mode: vertical-lr;
    line-height: calc(var(--content-width) - var(--border-width) / 2);
    background-color: white;
    border: var(--border-width) solid steelblue;

    --content-width: 1.5em;
    --border-width: 4px;
    --width: calc(1.5em + var(--border-width));
}

input {
    position: fixed;
    top: 4px;
    right: 4px;
    z-index: 1;
}
    </style>
    <script>
function updateComputedValues()
{
    document.querySelector(".inner-height").style.height = window.innerHeight + "px";

    for (let span of document.querySelectorAll("span"))
        span.textContent = "(" + window.getComputedStyle(span.parentNode).height + ")";
}

window.addEventListener("resize", () => {
    updateComputedValues();
});

window.addEventListener("load", () => {
    let index = 0;
    function createDiv(height) {
        let div = document.body.appendChild(document.createElement("div"));
        div.style.setProperty("--index", index++);
        div.style.setProperty("height", height);
        div.textContent = height + " ";

        let span = div.appendChild(document.createElement("span"));

        return div;
    }

    let fixed = createDiv("fixed");
    fixed.style.setProperty("position", "fixed");
    fixed.style.setProperty("height", "100%");

    let windowInnerHeight = createDiv("inner-height");
    windowInnerHeight.className = "inner-height";

    [
        "100%",
        "100vh",
        "100svh",
        "100lvh",
        "100dvh",
        "calc(100vh - env(safe-area-inset-bottom))",
        "-webkit-fill-available",
    ].forEach((height) => {
        createDiv(height);
    });

    updateComputedValues();
});
    </script>
</head>
<body>
	<input>
</body>
</html>