/* Terminal layout, rows, cursor, and the keyboard sink. */

*,
*::before,
*::after {
  box-sizing: border-box;
}

:root {
  /* System monospace, deliberately. Zero bytes, zero FOUT (a terminal that
   * reflows after a webfont loads looks broken), guaranteed box-drawing
   * coverage -- and it looks native: the visitor sees the font their own
   * terminal uses, which increases perceived authenticity rather than
   * imposing a designer font. */
  --font-mono: ui-monospace, "SF Mono", SFMono-Regular, Menlo, Consolas,
    "DejaVu Sans Mono", "Liberation Mono", monospace;

  /* Media query rather than clamp(), to keep integer pixel sizes for the
   * pixel-font path. */
  --font-size: 14px;
  --line-height: 20px; /* 14 * 1.4 = 19.6, rounded to an integer */
  --pad: 8px;
}
@media (min-width: 480px) {
  :root {
    --font-size: 16px;
    --line-height: 22px; /* 16 * 1.4 = 22.4, rounded to an integer */
    --pad: 16px;
  }
}

html,
body {
  margin: 0;
  padding: 0;
  height: 100%;
  background: var(--bg);
}

body {
  color: var(--fg);
  font-family: var(--font-mono);
  font-size: var(--font-size);
  line-height: var(--line-height);
  font-variant-ligatures: none;
  -webkit-font-smoothing: antialiased;
}

/* ── Terminal shell ───────────────────────────────────────────────────── */
#terminal {
  position: relative;
  /* 100dvh tracks the mobile URL bar; the visualViewport listener in
   * terminal.js overrides this when the on-screen keyboard is up. */
  height: 100vh;
  height: 100dvh;
  overflow: hidden;
  background: var(--bg);
  touch-action: manipulation; /* drop the 300ms tap delay */
}

#terminal:has(.kbd-sink:focus-visible) {
  outline: 2px solid var(--focus-ring);
  outline-offset: -2px;
}

.viewport {
  position: relative;
  z-index: 1;
  height: 100%;
  overflow-y: auto;
  overflow-x: hidden;
  overscroll-behavior: contain;
  /* Never `smooth`. Terminals do not animate scroll. */
  scroll-behavior: auto;
  padding: var(--pad);

  /* Reserve the scrollbar gutter permanently. Without this, the first write
   * makes a scrollbar appear, which shrinks the content width, which fires the
   * ResizeObserver, which re-measures the column count, which re-wraps and
   * re-renders -- a feedback path that converges in practice but can oscillate
   * when content sits right at the overflow threshold. Reserving the gutter
   * removes the whole class of bug, and it also matches a real terminal, whose
   * width does not jump when output appears. */
  scrollbar-gutter: stable;
  scrollbar-width: thin;
  scrollbar-color: var(--nord3) transparent;
}

/* ── CRT power-on flash ─────────────────────────────────────────────────
 * One shot, on load. Opacity and filter ONLY -- deliberately no transform.
 * Scaling the terminal would change its layout width mid-animation, and the
 * column count is measured from that width, so the entire grid would be computed
 * against a transient size. Gated on the CRT setting and skipped under
 * prefers-reduced-motion by boot.js, which sets the attribute. */
@keyframes power-on {
  from {
    opacity: 0;
    filter: brightness(2.4) contrast(1.4);
  }
  60% {
    opacity: 1;
  }
  to {
    opacity: 1;
    filter: brightness(1) contrast(1);
  }
}
#terminal[data-power-on="1"] {
  animation: power-on 180ms ease-out;
}
@media (prefers-reduced-motion: reduce) {
  #terminal[data-power-on="1"] {
    animation: none;
  }
}

/* ── Output rows ──────────────────────────────────────────────────────── */
.output {
  /* Chrome's scroll anchoring otherwise fights programmatic scroll during
   * streaming output. */
  overflow-anchor: none;
}

.row {
  /* Hard-wrapped at emit time to the measured column count; pre-wrap is the
   * safety net so shrinking the window soft-wraps instead of clipping or
   * introducing horizontal scroll. */
  white-space: pre-wrap;
  overflow-wrap: anywhere;
  min-height: var(--line-height);
}

.output,
.inputline {
  user-select: text;
}
.prompt,
.cursor {
  user-select: none; /* keep them out of copied text */
}

::selection {
  background: var(--selection-bg);
  color: var(--nord6);
}

/* Links must occupy exactly their character cells: no padding, margin,
 * border, or font change. */
.row a,
.inputline a {
  color: var(--link);
  text-decoration: underline;
  text-underline-offset: 2px;
  text-decoration-thickness: 1px;
}
.row a:hover,
.row a:focus-visible {
  color: var(--link-hover);
}

/* ── Input line ─────────────────────────────────────────────────────────
 * Given an accent treatment so the line being typed on is unmistakable against
 * a screen full of scrollback. The negative margins bleed the tint to the
 * viewport edges while the compensating padding keeps the text on exactly the
 * same left column as the output rows above -- emphasis without indentation,
 * which is the entire point. */
.inputline {
  white-space: pre-wrap;
  overflow-wrap: anywhere;
  min-height: var(--line-height);

  position: relative;
  background: var(--bg-alt);
  border-left: 2px solid var(--prompt-chevron);
  margin-inline: calc(-1 * var(--pad));
  padding-left: calc(var(--pad) - 2px);
  padding-right: var(--pad);
  padding-block: 2px;
  transition: background-color 120ms linear, border-color 120ms linear;
}

/* Unfocused, the emphasis recedes -- it marks where input *would* go, and
 * claiming otherwise while the keyboard is elsewhere would be a lie. Pairs with
 * the cursor going hollow. */
#terminal[data-focused="false"] .inputline {
  background: transparent;
  border-left-color: var(--rule);
}

@media (prefers-reduced-motion: reduce) {
  .inputline {
    transition: none;
  }
}
/* The tint is decoration, not information: at high contrast the border alone
 * carries the emphasis. */
@media (prefers-contrast: more) {
  .inputline {
    background: transparent;
  }
}

.cursor {
  display: inline-block;
  min-width: 1ch;
  background: var(--cursor-bg);
  color: var(--cursor-fg);
}
/* An author `display` declaration beats the UA stylesheet's [hidden]
 * { display: none }, so hiding the cursor for a non-editable mode needs this
 * explicitly. Without it, setting .hidden on the cursor does nothing. */
.cursor[hidden] {
  display: none;
}
/* steps(1, end) -- hard on/off. A fade is an instant "this is a web page"
 * tell. Blinking is suppressed while typing by toggling data-blink. */
.cursor[data-blink="true"] {
  animation: blink 1.06s steps(1, end) infinite;
}
@keyframes blink {
  0%,
  49.9% {
    opacity: 1;
  }
  50%,
  100% {
    opacity: 0;
  }
}
/* Unfocused: hollow outline, no blink. Every real terminal does this. */
#terminal[data-focused="false"] .cursor {
  animation: none;
  background: transparent;
  color: inherit;
  box-shadow: inset 0 0 0 1px var(--cursor-bg);
}
@media (prefers-reduced-motion: reduce) {
  .cursor[data-blink="true"] {
    animation: none;
  }
}

/* ── Keyboard sink ────────────────────────────────────────────────────────
 * A real, focusable <textarea> -- the only approach that gets the mobile
 * on-screen keyboard, native paste with text/plain, and IME composition all
 * at once. It is an acquisition device only; line-buffer.js is the source of
 * truth and this element's value is cleared after every input event.
 *
 * Hidden via opacity, NOT display:none / visibility:hidden (both prevent
 * focus and the OSK) and NOT left:-9999px (iOS scrolls the page sideways when
 * the keyboard opens).
 *
 * font-size MUST stay >= 16px even though it is invisible: iOS Safari
 * auto-zooms the page when focusing any input below 16px. This is the single
 * most common mobile-terminal bug. */
.kbd-sink {
  position: absolute;
  width: 1px;
  height: 1em;
  padding: 0;
  border: 0;
  margin: 0;
  opacity: 0;
  resize: none;
  overflow: hidden;
  font-size: 16px;
  font-family: inherit;
  line-height: 1;
  color: transparent;
  background: transparent;
  caret-color: transparent;
  white-space: pre;
  z-index: 0;
}

/* ── Cell-measurement probe ───────────────────────────────────────────────
 * Must inherit the exact font context of .row. metrics.js measures a
 * 100-character run here and divides, which avoids per-glyph subpixel
 * rounding error. */
.metrics {
  position: absolute;
  visibility: hidden;
  pointer-events: none;
  top: -9999px;
  left: 0;
  white-space: pre;
  font-family: var(--font-mono);
  font-size: var(--font-size);
  line-height: var(--line-height);
}

/* ── Soft keys (mobile only) ──────────────────────────────────────────────
 * Not decoration: iOS and Android software keyboards have no Ctrl key and no
 * arrow keys, so without these, history, completion, and abort are literally
 * unreachable on a phone. Wired up in M14. */
.softkeys {
  display: none;
}
@media (pointer: coarse) {
  /* The toolbar is positioned over the bottom of the viewport, so the viewport has
   * to give up that much room -- otherwise the bar covers the input line, which is
   * the one thing it exists to let you reach. Matches the button height below
   * (10px + 10px padding + one line). */
  #terminal:has(.softkeys:not([hidden])) .viewport {
    padding-bottom: calc(var(--pad) + var(--line-height) + 20px);
  }

  .softkeys:not([hidden]) {
    display: flex;
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    z-index: 3;
    gap: 1px;
    background: var(--bg-alt);
  }
  .softkeys button {
    flex: 1;
    padding: 10px 0;
    border: 0;
    background: var(--bg-alt);
    color: var(--fg);
    font-family: inherit;
    font-size: var(--font-size);
  }
  .softkeys button:active {
    background: var(--selection-bg);
  }
}

/* ── Accessibility helpers ────────────────────────────────────────────── */
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip-path: inset(50%);
  white-space: nowrap;
  border: 0;
}

.skip-link {
  position: absolute;
  top: -100px;
  left: var(--pad);
  z-index: 10;
  padding: 8px 12px;
  background: var(--bg-alt);
  color: var(--fg-bright);
  text-decoration: underline;
}
.skip-link:focus {
  top: var(--pad);
}

/* ── The ?plain=1 document view ────────────────────────────────────────────
 * Kept in this stylesheet rather than a fourth file: a separate request on every
 * page load, to style a view most visitors never open, is the wrong trade. The
 * rules are scoped to [data-view="plain"] and cost nothing otherwise.
 *
 * Deliberately not a terminal. Someone who followed the skip link asked for a
 * document, so this is a document: proportional text, generous measure, real
 * heading hierarchy. It keeps the Nord palette because that is the site's
 * identity, not because it is pretending to be a screen. */
:root[data-view="plain"] body {
  /* The terminal's overflow lock does not apply here; this page scrolls. */
  overflow: auto;
  background: var(--bg);
  color: var(--fg);
}

.plain {
  /* ~70 characters at this size: the measure prose is actually readable at. */
  max-width: 42rem;
  margin: 0 auto;
  padding: 2rem 1.25rem 4rem;
  font-family: system-ui, -apple-system, "Segoe UI", sans-serif;
  font-size: 1rem;
  line-height: 1.6;
}

.plain h1 {
  font-size: 1.75rem;
  line-height: 1.2;
  margin: 0 0 0.5rem;
  color: var(--fg-bright);
}
.plain h2 {
  font-size: 1.15rem;
  margin: 2.5rem 0 0.75rem;
  padding-bottom: 0.25rem;
  border-bottom: 1px solid var(--rule);
  color: var(--accent);
}
.plain h3 {
  font-size: 1rem;
  margin: 1.5rem 0 0.25rem;
  color: var(--fg-bright);
}

.plain p {
  margin: 0 0 0.75rem;
}
/* The meta line under each heading -- location and dates. */
.plain h3 + p {
  margin: 0 0 0.5rem;
  color: var(--fg-dim);
  font-size: 0.9rem;
}

.plain ul {
  margin: 0 0 1rem;
  padding-left: 1.25rem;
}
.plain li {
  margin-bottom: 0.35rem;
}

.plain dl {
  margin: 0;
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 0.35rem 1rem;
}
.plain dt {
  color: var(--fg-dim);
  font-size: 0.9rem;
}
.plain dd {
  margin: 0;
}
@media (max-width: 30rem) {
  /* Two columns at 375px leaves nothing for the values. */
  .plain dl {
    display: block;
  }
  .plain dd {
    margin: 0 0 0.5rem;
  }
}

.plain a {
  color: var(--link);
}
.plain a:focus-visible {
  outline: 2px solid var(--focus-ring);
  outline-offset: 2px;
}

.plain footer {
  margin-top: 3rem;
  padding-top: 1rem;
  border-top: 1px solid var(--rule);
  color: var(--fg-dim);
  font-size: 0.9rem;
}