/*
 * Overflow panel (issue #12; spec R-6.1, R-6.2, R-6.4)
 * ====================================================
 *
 * The DOM is built by public/js/overflow.js. Consumes the tokens in
 * public/css/tokens.css; no colours, fonts or radii are hard-coded here.
 *
 * A full-height panel flush with the right edge, as in the demo (x=2536 to
 * 3095 of 3096, top to bottom; docs/requirements/video-measurements.md).
 * The top-right keyboard glyph and the bottom-right XYZ tag stay where they
 * are, drawn over the panel (the chrome's z-index is above the panel's), and
 * the panel's padding keeps its content clear of both; the XYZ tag is lit
 * while the panel is open (write-on.css). The title
 * is the cursive display face in lavender; the text area uses the document's
 * monospace face; the footer hint is dim. While it is open
 * (<body data-te-overflow="open">) the writing column is centred in the
 * space left of the panel instead of running underneath it.
 */

/*
 * The same 18% of the window as the alternatives panel (R-6.1; measured in
 * docs/requirements/video-measurements.md), with the same clamp: the 12rem
 * floor keeps the title and its close button on one line and takes over below
 * a 1067px window; the 20rem cap is reached at 1778px. Declared on :root so
 * the writing column's clearance below uses the same value. Below 40rem the
 * narrow-screen rule replaces the width.
 */
:root {
    --te-overflow-width: clamp(12rem, 18vw, 20rem);
}

.te-overflow {
    position: fixed;
    top: 0;
    right: 0;
    bottom: 0;
    z-index: 18;
    box-sizing: border-box;
    display: flex;
    flex-direction: column;
    width: var(--te-overflow-width);
    /* Clear of the corner controls: 1.25rem offset plus a 1.75rem control,
       and a little air, at the top and the bottom. */
    padding: 3.75rem 1.25rem 4.25rem;
    background-color: var(--te-color-panel);
    border-left: 1px solid var(--te-color-panel-border);
    color: var(--te-color-text);
    font-family: var(--te-font-mono);
}

.te-overflow[hidden] {
    display: none;
}

.te-overflow-header {
    display: flex;
    align-items: baseline;
    justify-content: space-between;
    gap: 0.5rem;
}

.te-overflow-title {
    margin: 0;
    color: var(--te-color-accent);
    font-family: var(--te-font-display);
    font-size: 1.9rem;
    font-weight: 400;
    line-height: 1.1;
}

.te-overflow-tools {
    display: flex;
    gap: 0.25rem;
}

.te-overflow-button {
    margin: 0;
    padding: 0.25rem 0.4rem;
    border: 0;
    border-radius: 4px;
    background: none;
    color: var(--te-color-text-dim);
    font: inherit;
    font-size: 0.85rem;
    cursor: pointer;
}

.te-overflow-button:hover {
    color: var(--te-color-text);
    background-color: var(--te-color-popover-hover);
}

.te-overflow-button:focus-visible {
    outline: 2px solid var(--te-color-accent);
    outline-offset: 2px;
}

.te-overflow-note {
    margin: 0.5rem 0 0;
    color: var(--te-color-text-dim);
    font-size: 0.75rem;
    line-height: 1.4;
}

.te-overflow-text {
    flex: 1 1 auto;
    min-height: 6rem;
    margin: 0.5rem 0 0;
    padding: 0.5rem 0;
    border: 0;
    border-top: 1px solid var(--te-color-panel-border);
    background: transparent;
    color: var(--te-color-text);
    caret-color: var(--te-color-accent);
    font-family: var(--te-font-mono);
    font-size: 0.875rem;
    line-height: var(--te-line-height);
    resize: none;
    outline: none;
    white-space: pre-wrap;
    overflow-wrap: anywhere;
}

.te-overflow-text::placeholder {
    color: var(--te-color-text-dim);
    opacity: 1;
}

.te-overflow-text::selection {
    background-color: var(--te-color-accent-soft);
}

.te-overflow-text:focus-visible {
    border-top-color: var(--te-color-accent-soft);
}

.te-overflow-text[readonly] {
    color: var(--te-color-text-dim);
}

.te-overflow-hint {
    margin: 0.5rem 0 0;
    padding-top: 0.5rem;
    border-top: 1px solid var(--te-color-panel-border);
    color: var(--te-color-text-dim);
    font-size: 0.75rem;
    letter-spacing: 0.02em;
}

/* Keep the writing column clear of the open panel on wide screens. */
@media (min-width: 60rem) {
    .te-app[data-mode="write-on"][data-te-overflow="open"],
    #app.te-app[data-mode="write-on"][data-te-overflow="open"] {
        padding-right: calc(var(--te-overflow-width) + 2rem);
    }
}

/* Narrow screens: a bottom sheet across the full width and the lower half
   of the window. The bottom corner controls stay on top of it, as they do on
   the full-height panel, and the padding keeps the text clear of them. */
@media (max-width: 40rem) {
    .te-overflow {
        left: 0;
        width: auto;
        top: auto;
        height: 50vh;
        padding-top: 1rem;
        border-left: 0;
        border-top: 1px solid var(--te-color-panel-border);
    }
}