/* Code Along: editor, virtual Uno, Serial Monitor and test results. Loaded only on code-along pages. */

.ca-header .lesson-meta { gap: 0.4rem; }
.ca-chapter-score strong.complete, .ca-nav-score.complete { color: #267a45; }
.ca-aligns ul { margin: 0.4rem 0 0; }
.ca-howto { border: 1px solid var(--border); border-radius: var(--radius); padding: 0.9rem 1.1rem; background: #fbf9fd; margin: 1rem 0; }
.ca-howto ol { margin: 0.4rem 0 0; padding-left: 1.2rem; }
.ca-howto li { margin: 0.15rem 0; }

.course-nav [data-chapter] { display: flex; justify-content: space-between; gap: 0.5rem; }
.ca-nav-score { color: var(--muted); font-size: 0.8rem; white-space: nowrap; }
.on-this-page a.completed::after { content: " ✓"; color: #267a45; font-weight: 800; }
.ca-notes { color: var(--muted); font-size: 0.95rem; }

/* ---- sections ----------------------------------------------------------------------------- */
.ca-example, .ca-exercise { margin: 2rem 0; }
.ca-example > h2, .ca-exercise h2 { margin-bottom: 0.4rem; }
.ca-exercise {
  border: 1px solid var(--border);
  border-left: 5px solid var(--purple);
  border-radius: var(--radius);
  padding: 1rem 1.2rem 1.2rem;
  background: #fff;
  box-shadow: var(--shadow);
}
.ca-exercise.is-passed { border-left-color: #3d9b5f; }
.ca-ex-head { display: flex; justify-content: space-between; align-items: flex-start; gap: 1rem; flex-wrap: wrap; }
.ca-ex-head h2 { margin: 0.1rem 0 0; border: 0; padding: 0; font-size: 1.3rem; }
.ca-ex-num, .ca-example-label { color: var(--pink); font-size: 0.78rem; font-weight: 800; text-transform: uppercase; letter-spacing: 0.08em; }
.ca-ex-tags { display: flex; gap: 0.4rem; align-items: center; flex-wrap: wrap; }
.ca-tag, .ca-status {
  font-size: 0.78rem;
  font-weight: 800;
  border-radius: 999px;
  padding: 0.2rem 0.65rem;
  background: #eef2f5;
  color: var(--muted);
}
.ca-tag.deeper { background: var(--note-bg); color: var(--purple-deep); }
.ca-status.progress { background: var(--tip-bg); color: #8a6100; }
.ca-status.passed { background: var(--ok-bg); color: #267a45; }
.ca-prompt p:first-child { margin-top: 0.6rem; }

.ca-sample { margin: 0.8rem 0; }
.ca-sample > span { display: block; font-size: 0.8rem; font-weight: 800; color: var(--muted); text-transform: uppercase; letter-spacing: 0.06em; margin-bottom: 0.25rem; }
.ca-sample pre, .ca-serial {
  margin: 0;
  background: #0d1117;
  color: #d8e1e8;
  font-family: var(--mono);
  font-size: 0.86rem;
  line-height: 1.45;
  padding: 0.7rem 0.9rem;
  border-radius: 8px;
  overflow-x: auto;
  white-space: pre;
}

/* ---- toolbar ------------------------------------------------------------------------------ */
.ca-widget { margin-top: 0.8rem; }
.ca-js-note { color: var(--muted); font-size: 0.9rem; }
.ca-toolbar { display: flex; flex-wrap: wrap; gap: 0.45rem; align-items: center; margin-bottom: 0.55rem; }
.ca-toolbar-spacer { flex: 1 1 auto; }
.ca-btn {
  font: inherit;
  font-size: 0.9rem;
  font-weight: 700;
  min-height: 40px;
  padding: 0.4rem 0.85rem;
  border-radius: 8px;
  border: 1px solid var(--border);
  background: #fff;
  color: var(--action);
  cursor: pointer;
}
.ca-btn:hover { border-color: var(--action-hover); color: var(--action-hover); }
.ca-btn.primary { background: var(--action); border-color: var(--action); color: #fff; }
.ca-btn.primary:hover { background: var(--action-hover); border-color: var(--action-hover); color: #fff; }
.ca-btn.ghost { background: transparent; color: var(--muted); }
.ca-btn.locked::after { content: " 🔒"; font-size: 0.8em; }
.ca-btn:disabled { opacity: 0.55; cursor: not-allowed; }
.ca-btn:focus-visible, .ca-speed:focus-visible, .ca-link-btn:focus-visible, .ca-push:focus-visible { outline: 3px solid #0ca1a6; outline-offset: 2px; }
.ca-speed, .ca-line-ending {
  font: inherit;
  font-size: 0.88rem;
  min-height: 40px;
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 0.3rem 0.5rem;
  background: #fff;
  color: var(--ink);
}
.ca-link-btn { font: inherit; font-size: 0.85rem; background: none; border: 0; color: var(--purple); cursor: pointer; padding: 0.2rem 0.3rem; }
.ca-link-btn:hover { color: var(--pink); text-decoration: underline; }

/* ---- editor ------------------------------------------------------------------------------- */
.ca-editor {
  --ca-lh: 1.5em;
  --ca-pad: 0.75rem;
  --ca-lines: 12;
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  height: calc(var(--ca-lines) * var(--ca-lh) + 2 * var(--ca-pad));
  background: var(--code-bg);
  border-radius: 10px;
  overflow: hidden;
  font-family: var(--mono);
  font-size: 0.9rem;
  line-height: var(--ca-lh);
}
.ca-editor:focus-within { box-shadow: 0 0 0 3px rgba(12, 161, 166, 0.55); }
.ca-gutter {
  padding: var(--ca-pad) 0.55rem var(--ca-pad) 0.75rem;
  background: #192023;
  color: #5c6370;
  text-align: right;
  user-select: none;
  overflow: hidden;
  min-width: 2.6rem;
}
.ca-gutter span { display: block; }
.ca-gutter span.err { color: #ff7b72; font-weight: 800; background: rgba(255, 80, 80, 0.18); }
.ca-gutter span.warn { color: #f0b429; font-weight: 800; }
.ca-code { position: relative; overflow: hidden; }
.ca-hl, .ca-input {
  position: absolute;
  inset: 0;
  margin: 0;
  padding: var(--ca-pad);
  border: 0;
  font: inherit;
  line-height: inherit;
  letter-spacing: normal;
  white-space: pre;
  tab-size: 2;
  overflow-wrap: normal;
}
.ca-hl { overflow: hidden; pointer-events: none; color: var(--code-fg); background: transparent; }
.ca-hl code { font: inherit; color: inherit; background: none; padding: 0; }
.ca-input {
  width: 100%;
  height: 100%;
  resize: none;
  overflow: auto;
  background: transparent;
  color: transparent;
  caret-color: #ffffff;
  outline: none;
  -webkit-text-fill-color: transparent;
}
.ca-input::selection { background: rgba(12, 161, 166, 0.45); -webkit-text-fill-color: transparent; }
.ca-marks { position: absolute; left: 0; right: 0; top: var(--ca-pad); pointer-events: none; }
.ca-mark { position: absolute; left: 0; right: 0; height: var(--ca-lh); }
.ca-mark.err { background: rgba(255, 80, 80, 0.22); }
.ca-mark.warn { background: rgba(240, 180, 41, 0.14); }

/* ---- hints, diagnostics, solution --------------------------------------------------------- */
.ca-hints { background: var(--tip-bg); border-left: 5px solid #d4a017; border-radius: 8px; padding: 0.7rem 1rem 0.7rem 2.2rem; margin: 0.7rem 0; }
.ca-hints li { margin: 0.25rem 0; }
.ca-diagnostics:empty { display: none; }
.ca-diagnostics { margin: 0.7rem 0; display: grid; gap: 0.45rem; }
.ca-diag { border-radius: 8px; padding: 0.55rem 0.8rem; font-size: 0.93rem; }
.ca-diag p { margin: 0.25rem 0 0; }
.ca-diag.error { background: var(--warn-bg); border-left: 5px solid #d9534f; }
.ca-diag.warning { background: var(--tip-bg); border-left: 5px solid #d4a017; }
.ca-diag.note { background: #eef2f5; border-left: 5px solid var(--action); }
.ca-diag-line { font: inherit; font-family: var(--mono); font-size: 0.86rem; font-weight: 700; color: var(--ink); background: none; border: 0; padding: 0; cursor: pointer; text-align: left; }
.ca-diag-line:hover { text-decoration: underline; }
.ca-solution { margin: 0.8rem 0; }
.ca-solution-head { display: flex; justify-content: space-between; align-items: center; }
.ca-solution-note, .ca-locked { color: var(--muted); font-size: 0.9rem; }

/* ---- simulator ---------------------------------------------------------------------------- */
.ca-sim { display: grid; grid-template-columns: minmax(0, 15rem) minmax(0, 1fr); gap: 0.75rem; margin-top: 0.75rem; }
.ca-sim[hidden] { display: none; }
.ca-board {
  background: linear-gradient(160deg, #0b5c63, #084449);
  color: #e6f4f1;
  border-radius: 10px;
  padding: 0.75rem;
  display: flex;
  flex-direction: column;
  gap: 0.6rem;
}
.ca-board-title { display: flex; justify-content: space-between; align-items: baseline; gap: 0.5rem; flex-wrap: wrap; font-size: 0.9rem; }
.ca-clock { font-family: var(--mono); font-size: 0.75rem; color: #a9d6d2; }
.ca-board-empty { margin: 0; font-size: 0.85rem; color: #e6f4f1; opacity: 0.9; }
.ca-led { display: flex; align-items: center; gap: 0.6rem; font-size: 0.88rem; --level: 0; }
.ca-led-bulb {
  width: 1.2rem;
  height: 1.2rem;
  border-radius: 50%;
  border: 2px solid rgba(255, 255, 255, 0.35);
  background: color-mix(in srgb, var(--led) calc(var(--level) * 100%), #2b3236);
  box-shadow: 0 0 calc(var(--level) * 14px) calc(var(--level) * 3px) var(--led);
  transition: background 60ms linear, box-shadow 60ms linear;
}
.ca-component { display: flex; flex-direction: column; gap: 0.2rem; }
.ca-component small { color: #a9d6d2; font-size: 0.75rem; }
.ca-push {
  font: inherit;
  font-size: 0.88rem;
  font-weight: 700;
  min-height: 44px;
  border-radius: 999px;
  border: 2px solid #cfe9e6;
  background: #1c2430;
  color: #fff;
  cursor: pointer;
  touch-action: none;
  user-select: none;
}
.ca-push.down { background: #cb287a; border-color: #ffb3d6; transform: translateY(1px); }
.ca-pot { display: grid; grid-template-columns: 1fr auto; gap: 0.2rem 0.5rem; font-size: 0.88rem; }
.ca-pot input { grid-column: 1 / -1; width: 100%; accent-color: #ffd23f; }
.ca-pot output { font-family: var(--mono); grid-row: 1; grid-column: 2; }
.ca-screen { display: flex; flex-direction: column; gap: 0.3rem; }
.ca-screen-label { font-size: 0.8rem; color: #cfe9e6; }
.ca-lcd {
  display: inline-block;
  padding: 0.45rem 0.5rem;
  border-radius: 6px;
  background: #123b2a;
  border: 2px solid #0a2a1e;
  font-family: var(--mono);
  font-size: 0.86rem;
  line-height: 1.35;
  letter-spacing: 0.08em;
  color: #2f6f52;
  white-space: pre;
  transition: background 120ms linear, color 120ms linear;
}
.ca-lcd.lit { background: #1f7a4d; color: #d9ffe9; box-shadow: 0 0 12px rgba(60, 220, 140, 0.35); }
.ca-lcd-line { min-height: 1.2em; }
.ca-motor { display: flex; justify-content: space-between; gap: 0.5rem; font-size: 0.88rem; }
.ca-motor.running .ca-motor-state { color: #ffd23f; font-weight: 800; }
.ca-buzzer { display: flex; justify-content: space-between; gap: 0.5rem; font-size: 0.88rem; }
.ca-buzzer.on .ca-buzz-state { color: #ffd23f; font-weight: 800; }
.ca-serial-panel { display: flex; flex-direction: column; gap: 0.4rem; min-width: 0; }
.ca-serial-head { display: flex; gap: 0.6rem; align-items: baseline; font-size: 0.9rem; }
.ca-baud { color: var(--muted); font-size: 0.8rem; margin-right: auto; }
.ca-serial-panel .ca-serial { flex: 1 1 auto; min-height: 9rem; max-height: 18rem; overflow: auto; }
.ca-serial-form { display: flex; gap: 0.4rem; flex-wrap: wrap; }
.ca-serial-form[hidden] { display: none; }
.ca-serial-text { flex: 1 1 10rem; font: inherit; font-family: var(--mono); font-size: 0.88rem; min-height: 40px; border: 1px solid var(--border); border-radius: 8px; padding: 0.3rem 0.6rem; }

/* ---- results ------------------------------------------------------------------------------ */
.ca-results:empty { display: none; }
.ca-results { margin-top: 0.9rem; }
.ca-testing { color: var(--muted); font-style: italic; }
.ca-summary { margin: 0 0 0.5rem; padding: 0.6rem 0.8rem; border-radius: 8px; }
.ca-summary.pass { background: var(--ok-bg); border-left: 5px solid #3d9b5f; }
.ca-summary.fail { background: #fff1f8; border-left: 5px solid var(--pink); }
.ca-result-list { list-style: none; margin: 0; padding: 0; display: grid; gap: 0.35rem; }
.ca-result-list li { display: grid; grid-template-columns: 1.5rem minmax(0, 1fr); gap: 0.35rem; padding: 0.45rem 0.7rem; border-radius: 8px; background: #f7f5f9; }
.ca-result-list li.ok { background: var(--ok-bg); }
.ca-result-list li.fail { background: var(--warn-bg); }
.ca-result-list p { margin: 0.2rem 0 0; }
.ca-result-list summary { cursor: pointer; font-weight: 700; }
.ca-result-list details[open] summary { margin-bottom: 0.2rem; }
.ca-result-icon { font-weight: 900; }
li.ok .ca-result-icon { color: #267a45; }
li.fail .ca-result-icon { color: #c0392b; }
.ca-detail { color: var(--muted); font-size: 0.9rem; }
.ca-diff { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 0.5rem; margin-top: 0.45rem; }
.ca-diff span { font-size: 0.75rem; font-weight: 800; color: var(--muted); text-transform: uppercase; letter-spacing: 0.05em; }
.ca-diff pre { margin: 0.15rem 0 0; background: #fff; border: 1px solid var(--border); border-radius: 6px; padding: 0.4rem 0.6rem; font-family: var(--mono); font-size: 0.82rem; overflow-x: auto; white-space: pre; }
.ca-test-output { margin-top: 0.6rem; }
.ca-test-output summary { cursor: pointer; color: var(--purple); font-weight: 700; }
.ca-test-output pre { margin-top: 0.4rem; max-height: 14rem; }

/* ---- testing banner ------------------------------------------------------------------------ */
.ca-banner {
  position: fixed;
  left: 50%;
  bottom: 1rem;
  transform: translateX(-50%);
  z-index: 60;
  display: flex;
  align-items: center;
  gap: 0.75rem;
  max-width: min(46rem, calc(100vw - 2rem));
  padding: 0.6rem 0.7rem 0.6rem 1rem;
  border-radius: 999px;
  border: 1px solid #d4a017;
  background: var(--tip-bg);
  color: var(--ink);
  font-size: 0.9rem;
  box-shadow: 0 10px 26px rgba(45, 20, 60, 0.22);
}
.ca-banner[hidden] { display: none; }
.ca-banner-close {
  flex: 0 0 auto;
  font: inherit;
  font-size: 1.3rem;
  line-height: 1;
  width: 2rem;
  height: 2rem;
  border-radius: 50%;
  border: 0;
  background: transparent;
  color: var(--muted);
  cursor: pointer;
}
.ca-banner-close:hover { background: #f0e2bd; color: var(--ink); }
.ca-banner-close:focus-visible { outline: 3px solid #0ca1a6; outline-offset: 2px; }
@media (max-width: 640px) {
  .ca-banner { border-radius: 12px; font-size: 0.85rem; bottom: 0.5rem; }
}
@media print { .ca-banner { display: none !important; } }

/* ---- index page --------------------------------------------------------------------------- */
.ca-intro { display: grid; grid-template-columns: minmax(0, 1.4fr) minmax(0, 1fr); gap: 1.5rem; align-items: start; }
.ca-steps { counter-reset: step; list-style: none; padding: 0; margin: 0; display: grid; gap: 0.5rem; }
.ca-steps li { counter-increment: step; display: grid; grid-template-columns: 2rem 1fr; gap: 0.5rem; align-items: start; }
.ca-steps li::before { content: counter(step); width: 1.7rem; height: 1.7rem; border-radius: 50%; background: var(--purple); color: #fff; font-weight: 800; display: grid; place-items: center; font-size: 0.85rem; }
.ca-chapters { display: grid; grid-template-columns: repeat(auto-fill, minmax(16rem, 1fr)); gap: 1rem; }
.ca-chapter-card { display: flex; flex-direction: column; gap: 0.35rem; border: 1px solid var(--border); border-radius: var(--radius); padding: 1rem; background: #fff; color: var(--ink); box-shadow: var(--shadow); }
.ca-chapter-card:hover { border-color: var(--purple); text-decoration: none; color: var(--ink); }
.ca-chapter-card h3 { margin: 0; }
.ca-chapter-card p { margin: 0; color: var(--muted); font-size: 0.95rem; }
.ca-card-meta { display: flex; justify-content: space-between; font-size: 0.85rem; color: var(--muted); margin-top: auto; padding-top: 0.4rem; }
.ca-tools { display: flex; flex-wrap: wrap; gap: 0.5rem; align-items: center; }
.ca-tools label.ca-btn { display: inline-flex; align-items: center; }
.ca-tools input[type="file"] { position: absolute; width: 1px; height: 1px; opacity: 0; }
.ca-tools-status { color: var(--muted); font-size: 0.9rem; }

@media (max-width: 760px) {
  .ca-sim, .ca-intro, .ca-diff { grid-template-columns: 1fr; }
  .ca-exercise { padding: 0.9rem; }
  .ca-editor { font-size: 0.82rem; }
  .ca-toolbar-spacer { display: none; }
}
@media (prefers-reduced-motion: reduce) {
  .ca-led-bulb { transition: none; }
}
@media print {
  .ca-toolbar, .ca-sim, .ca-results, .ca-diagnostics { display: none !important; }
}