fc-dioxus 0.1.2

/*!
 * future-css -- https://github.com/estith/future-css
 * A styling system for multi-language, multi-platform systems
 *
 * Regenerate with: npm run build
 * This file is generated; edit the sources in src/ instead.
 */
/*!
 * future-css -- terminal
 *
 * A terminal emulator surface: the output grid, the input line, and the chrome
 * around them.
 *
 * **Scope, stated plainly.** This is the presentation layer. Parsing escape
 * sequences, managing a PTY, scrollback buffers, and multiplexing belong to a
 * terminal engine (xterm.js and equivalents do this well and should be used).
 * What a design system owns is everything visible: grid geometry, the ANSI
 * palette, cursor states, selection, and the accessibility contract.
 *
 * # Why a terminal has its own palette
 *
 * Two reasons, both structural rather than stylistic:
 *
 *   1. **A terminal has its own background**, which is dark in *both* color
 *      schemes. An application that follows the OS into a light theme must not
 *      produce a light terminal -- every terminal theme ever written keeps it
 *      dark, and a light one is a genuine usability regression.
 *   2. **ANSI slots are hue-fixed by protocol.** `\e[31m` is red. A build log's
 *      red error means nothing rendered blue, so these are the only tokens in the
 *      system named by hue rather than by purpose.
 *
 * Both are enforced: `src/tokens/semantic/terminal.ts` declares 19 contrast
 * pairings checked at build time in both schemes. The first hand-written version
 * of that palette failed 16 of them.
 *
 * # Accessibility
 *
 * Terminals are the hardest surface to make accessible, and most of the work is
 * not visual:
 *
 *   - **The output region is a `log`**, so additions are announced politely
 *     rather than interrupting. Deliberately not `assertive`: a fast-running
 *     command would make a screen reader unusable.
 *   - **The input line is a real textbox**, not a `div`, so caret and IME
 *     composition work. Without this, an IME-composed character -- common in CJK
 *     and other composing scripts -- silently fails.
 *   - **Color is never the only signal.** A failed command carries its exit
 *     status as text, so a red line is not the only thing marking it.
 */

@layer fc.components {
  .fc-terminal {
    display: flex;
    flex-direction: column;
    min-inline-size: 0;
    /* A terminal needs a definite height; the consumer sets it. */
    block-size: 100%;

    background-color: var(--fc-term-bg);
    color: var(--fc-term-fg);
    border: var(--fc-border-width-thin) solid var(--fc-color-border-default);
    border-radius: var(--fc-radius-md);
    /* The terminal background is its own contrast environment, so it is never
       themed -- not even by high-contrast or reduced-transparency preferences. */
  }

  /*
   * The output grid.
   *
   * `min-block-size: 0` so it scrolls while the input line stays pinned -- the
   * same flex-shrink requirement as the webview frame, for the same reason.
   */
  .fc-terminal__output {
    flex: 1;
    min-block-size: 0;
    overflow-y: auto;
    overscroll-behavior-block: contain;
    padding: var(--fc-space-2) var(--fc-space-3);

    /*
     * Monospace is a functional requirement, not a style choice: a terminal
     * whose glyphs are proportional columns is unreadable, because column
     * alignment is how output is structured.
     */
    font-family: var(--fc-font-family-mono);
    font-size: var(--fc-font-size-sm);
    /* Terminal leading is conventionally ~1.2; more wastes vertical space, less
       collides descenders. */
    line-height: var(--fc-line-height-snug);
    /* Programming ligatures turn `!=` into one glyph and break column counting. */
    font-variant-ligatures: none;
    /*
     * Deliberately NOT `white-space: pre` here.
     *
     * That looks correct and is not. With `pre` on the container, every newline
     * and indent in the markup *between* line elements renders as a blank output
     * line -- so a 10-line document occupied 598px instead of 180px, and the
     * output scrolled when it had no reason to. Pre belongs on the line, where
     * the whitespace is meaningful, and nowhere else.
     */
    tab-size: 4;
  }

  /*
   * A line of output.
   *
   * Block, not inline: an inline element collapses trailing spaces, which carry
   * meaning in aligned output.
   */
  .fc-terminal__line {
    display: block;
    /*
     * `pre` lives here rather than on the container, so leading spaces and
     * column alignment are preserved within a line while the whitespace between
     * lines in the markup collapses to nothing.
     */
    white-space: pre;
    min-block-size: 1lh;
  }

  /* ---- ANSI colors ------------------------------------------------------- */

  /*
   * One class per SGR slot. There is deliberately no `.fc-terminal__text--danger`
   * here, and that absence is the point: a terminal's colors are chosen by the
   * *program's output*, not by the application's intent. The class mirrors the
   * escape sequence because that is what the content actually says.
   */
  .fc-term-ansi-black { color: var(--fc-term-ansi-black); }
  .fc-term-ansi-red { color: var(--fc-term-ansi-red); }
  .fc-term-ansi-green { color: var(--fc-term-ansi-green); }
  .fc-term-ansi-yellow { color: var(--fc-term-ansi-yellow); }
  .fc-term-ansi-blue { color: var(--fc-term-ansi-blue); }
  .fc-term-ansi-magenta { color: var(--fc-term-ansi-magenta); }
  .fc-term-ansi-cyan { color: var(--fc-term-ansi-cyan); }
  .fc-term-ansi-white { color: var(--fc-term-ansi-white); }

  .fc-term-ansi-bright-black { color: var(--fc-term-ansi-bright-black); }
  .fc-term-ansi-bright-red { color: var(--fc-term-ansi-bright-red); }
  .fc-term-ansi-bright-green { color: var(--fc-term-ansi-bright-green); }
  .fc-term-ansi-bright-yellow { color: var(--fc-term-ansi-bright-yellow); }
  .fc-term-ansi-bright-blue { color: var(--fc-term-ansi-bright-blue); }
  .fc-term-ansi-bright-magenta { color: var(--fc-term-ansi-bright-magenta); }
  .fc-term-ansi-bright-cyan { color: var(--fc-term-ansi-bright-cyan); }
  .fc-term-ansi-bright-white { color: var(--fc-term-ansi-bright-white); }

  /* ---- Text attributes --------------------------------------------------- */

  /*
   * Bold, dim, italic, underline, inverse.
   *
   * Dim is a real ANSI attribute and the one that most often breaks the contrast
   * contract -- which is why `--fc-term-fg-dim` is a defined, verified token at
   * 4.5:1 rather than a plain opacity on the default foreground. An opacity would
   * compound with whatever color the line already carries.
   */
  .fc-terminal__bold { font-weight: var(--fc-font-weight-bold); }
  .fc-terminal__dim { color: var(--fc-term-fg-dim); }
  .fc-terminal__italic { font-style: italic; }
  .fc-terminal__underline { text-decoration: underline; }
  .fc-terminal__strike { text-decoration: line-through; }

  /*
   * Inverse swaps foreground and background for the span.
   *
   * Both colors are explicit: relying on `color: inherit` with a background
   * would resolve against the wrong side inside a nested inverse.
   */
  .fc-terminal__inverse {
    color: var(--fc-term-bg);
    background-color: var(--fc-term-fg);
  }

  /* ---- Input line -------------------------------------------------------- */

  /* Flex so the prompt cannot wrap away from the caret. */
  .fc-terminal__input-row {
    display: flex;
    align-items: baseline;
    gap: var(--fc-space-2);
    padding: var(--fc-space-2) var(--fc-space-3);
    border-block-start: var(--fc-border-width-thin) solid var(--fc-color-border-subtle);
    min-inline-size: 0;
  }

  /* `flex-shrink: 0` so a long prompt truncates rather than crushing the input. */
  .fc-terminal__prompt {
    flex-shrink: 0;
    color: var(--fc-term-ansi-green);
    white-space: pre;
    user-select: none;
  }

  /*
   * A real `<input>`, so caret movement, selection, clipboard, undo, and IME
   * composition all work natively. Terminals that fake this with a contenteditable
   * div break IME input for every CJK user.
   */
  .fc-terminal__input {
    flex: 1;
    min-inline-size: 0;
    background: transparent;
    border: 0;
    padding: 0;
    color: var(--fc-term-fg);
    /* Inherits monospace from the parent so the caret column lines up with the
       output above it. */
    font: inherit;
  }

  /* ---- Cursor ------------------------------------------------------------ */

  /*
   * The block cursor.
   *
   * A real element rather than a pseudo-element on the input, because a cursor
   * must be selectable and must move with the caret as the user types -- neither
   * of which a pseudo-element can do.
   */
  .fc-terminal__cursor {
    display: inline-block;
    inline-size: 0.6em;
    block-size: 1em;
    background-color: var(--fc-term-cursor);
    color: var(--fc-term-bg);
    /* Sits on the text baseline without adding line height. */
    vertical-align: text-bottom;
  }

  /*
   * The blinking variant.
   *
   * The blink is the one animation here and it carries meaning -- it is how the
   * user knows the shell is waiting. Under reduced motion it becomes a static
   * block rather than nothing, keeping the signal without the motion.
   */
  .fc-terminal__cursor--blink {
    animation: fc-cursor-blink 1.06s step-end infinite;
  }

  @keyframes fc-cursor-blink {
    50% {
      opacity: 0;
    }
  }

  @media (prefers-reduced-motion: reduce) {
    .fc-terminal__cursor--blink {
      animation: none;
    }
  }

  /* ---- Status bar -------------------------------------------------------- */

  /*
   * Describes the terminal rather than the application, so it follows the terminal
   * background rather than the app chrome.
   */
  .fc-terminal__status {
    display: flex;
    align-items: center;
    gap: var(--fc-space-3);
    padding-block: var(--fc-space-1);
    padding-inline: var(--fc-space-3);
    background-color: var(--fc-term-bg-raised);
    color: var(--fc-term-fg-dim);
    border-block-start: var(--fc-border-width-thin) solid var(--fc-color-border-subtle);
    font-family: var(--fc-font-family-mono);
    font-size: var(--fc-font-size-2xs);
  }

  /* Pushes the last item to the inline end -- an exit code, typically. */
  .fc-terminal__status-end {
    margin-inline-start: auto;
  }

  /*
   * Exit status, colored AND prefixed with a word.
   *
   * A red "127" alone is a color-only signal; "exit 127" survives greyscale and
   * forced colors.
   */
  .fc-terminal__exit {
    font-variant-numeric: tabular-nums;
  }

  .fc-terminal__exit[data-fc-state="error"] {
    color: var(--fc-term-ansi-red);
  }

  .fc-terminal__exit[data-fc-state="complete"] {
    color: var(--fc-term-ansi-green);
  }

  /* ---- Selection --------------------------------------------------------- */

  /*
   * Scoped to the output rather than global: selecting terminal output deserves
   * its own treatment and should not inherit the app's selection color.
   */
  .fc-terminal__output::selection {
    background-color: var(--fc-term-ansi-blue);
    color: var(--fc-term-bg);
  }

  /* ---- State ------------------------------------------------------------- */

  /* A dimmed input row rather than a color change: the output may be frozen or
     erroring, and a user needs to know the session is over, not merely idle. */
  .fc-terminal[data-fc-state="disconnected"] .fc-terminal__input-row {
    opacity: 0.6;
  }

  @media (forced-colors: active) {
    .fc-terminal {
      /* The terminal background is forced to Canvas, so the text must be forced
         to CanvasText or the output becomes unreadable. Here honoring forced
         colors is a matter of legibility, not preference. */
      background-color: Canvas;
      color: CanvasText;
      border-color: CanvasText;
    }

    /* Success and failure collapse to one color: in forced-colors mode there is
       no hue to distinguish them, which is why the visible label carries the
       state as text as well. */
    .fc-term-ansi-red,
    .fc-term-ansi-bright-red,
    .fc-term-ansi-green,
    .fc-term-ansi-bright-green {
      color: LinkText;
    }

    .fc-terminal__cursor {
      background-color: CanvasText;
      color: Canvas;
    }

    .fc-terminal__status {
      background-color: Canvas;
      color: CanvasText;
      border-block-start-color: CanvasText;
    }
  }
}