/* shio learn — styles for /learn/ and chapter pages.
 *
 * Extends styles.css with terminal-specific tokens, keyboard accessory,
 * lesson layout, and the mode-picker overlay.
 *
 * Lowercase everywhere, no exclamations, tertiary errors. Match setup.html
 * rhythm: 16/24/48 spacing, dashed terminal rules, Departure Mono for
 * shell context, SF Pro Text for prose.
 */

:root {
  /* terminal palette — all derived from semantic tokens so theme swaps work */
  --term-bg: var(--chrome-surface);
  --term-fg: var(--text-primary);
  --term-stdin: var(--text-primary);
  --term-stdout: var(--text-secondary);
  --term-stderr: var(--text-tertiary);
  --term-prompt: var(--text-tertiary);
  --term-border: color-mix(in srgb, var(--text-primary) 10%, transparent);

  /* keyboard accessory */
  --keycap-bg: color-mix(in srgb, var(--text-primary) 8%, transparent);
  --keycap-fg: var(--text-primary);
  --keycap-pending-bg: color-mix(in srgb, var(--text-primary) 85%, transparent);
  --keycap-pending-fg: var(--chrome-surface);
  --keycap-locked-bg: var(--text-primary);
  --keycap-locked-fg: var(--chrome-surface);
  --keycap-down-bg: color-mix(in srgb, var(--text-primary) 16%, transparent);
}

/* ── /learn/ page chrome ───────────────────────────────────────── */

.page-learn main {
  display: block;
  padding: 0;
  width: 100%;
}

.learn {
  max-width: 36rem;
  width: 100%;
  margin: 0 auto;
  padding: 0 var(--space-lg);
}

@media (min-width: 640px) {
  .learn {
    max-width: 38rem;
    padding: 0 var(--space-xl);
  }
}

.learn-hero {
  margin-top: var(--space-xl);
}
.learn-hero h1 {
  margin: 0 0 var(--space-md);
  font: 600 32px/40px var(--font-display);
  letter-spacing: -0.02em;
  color: var(--text-primary);
  text-wrap: balance;
}
.learn-sub {
  margin: 0;
  font: 400 17px/26px var(--font-chrome);
  color: var(--text-secondary);
  text-wrap: pretty;
}
@media (min-width: 640px) {
  .learn-hero h1 { font-size: 38px; line-height: 46px; }
  .learn-sub { font-size: 18px; line-height: 28px; }
}

.learn-preamble {
  margin-top: var(--space-xl);
}
.learn-preamble p {
  margin: 0;
  font: 400 16px/26px var(--font-chrome);
  color: var(--text-primary);
}
.learn-preamble p + p { margin-top: var(--space-lg); }
@media (min-width: 640px) {
  .learn-preamble p { font-size: 17px; line-height: 28px; }
}

/* ── Sandbox callout (subtle CTA above the chapter list) ───────── */

.sandbox-callout {
  margin: var(--space-xl) 0 0;
}
.sandbox-link {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 8px 12px 8px 14px;
  background: color-mix(in srgb, var(--text-primary) 5%, transparent);
  border: 0.5px solid color-mix(in srgb, var(--text-primary) 14%, transparent);
  border-radius: 8px;
  color: var(--text-primary);
  font: 400 13px/1 var(--font-wordmark);
  letter-spacing: 0.02em;
  text-transform: lowercase;
  cursor: pointer;
  transition:
    background 120ms var(--ease-standard),
    border-color 120ms var(--ease-standard),
    transform 120ms var(--ease-standard);
}
.sandbox-link:hover {
  background: color-mix(in srgb, var(--text-primary) 9%, transparent);
  border-color: color-mix(in srgb, var(--text-primary) 24%, transparent);
}
.sandbox-link:active { transform: translateY(0.5px); }
.sandbox-link:focus-visible {
  outline: 2px solid var(--text-primary);
  outline-offset: 3px;
}
.sandbox-link-sigil {
  color: var(--text-tertiary);
  font-size: 12px;
  letter-spacing: 0;
}
.sandbox-link-label { color: var(--text-primary); }
.sandbox-link-hint {
  margin-left: 4px;
  padding: 2px 6px;
  border-radius: 4px;
  background: color-mix(in srgb, var(--text-primary) 10%, transparent);
  color: var(--text-tertiary);
  font-size: 11px;
  letter-spacing: 0.04em;
}

/* ── Chapter list (on /learn/ index) ───────────────────────────── */

.chapter-list {
  list-style: none;
  margin: var(--space-xl) 0 0;
  padding: 0;
}
.chapter-list li {
  display: grid;
  grid-template-columns: 2.4em 1fr;
  align-items: baseline;
  padding: var(--space-md) 0;
  border-top: 1px solid color-mix(in srgb, var(--text-primary) 10%, transparent);
}
.chapter-list li:first-child { border-top: 0; padding-top: 0; }
.chapter-list .chapter-num {
  font: 400 13px/1.4 var(--font-wordmark);
  letter-spacing: 0.02em;
  color: var(--text-tertiary);
}
.chapter-list .chapter-title {
  font: 400 16px/22px var(--font-chrome);
  color: var(--text-primary);
}
.chapter-list .chapter-title a {
  color: var(--text-primary);
  text-decoration-color: color-mix(in srgb, currentColor 30%, transparent);
}
.chapter-list .chapter-desc {
  grid-column: 2;
  font: 400 14px/22px var(--font-chrome);
  color: var(--text-tertiary);
  margin-top: 2px;
}

/* ── Ambient layer — dialed way back on text-heavy pages ────────── */

.page-learn #ambient,
.page-lesson #ambient { opacity: 0.018; }

/* Safe zone: a chrome-background panel sized to main's full content
 * height (not just the viewport), centered behind the reading column.
 * Ambient stays visible in the side gutters on desktop; behind the
 * text it's masked the whole way down, no matter how long the page. */
.page-learn main,
.page-lesson main {
  position: relative;
  display: block;
  flex: 1 0 auto;            /* never shrink below content height */
  width: 100%;
}
.page-learn main::before,
.page-lesson main::before {
  content: "";
  position: absolute;
  top: 0;
  bottom: 0;
  left: 50%;
  transform: translateX(-50%);
  width: min(100%, 36rem);
  background: var(--chrome-background);
  z-index: 0;
  pointer-events: none;
}
@media (min-width: 640px) {
  .page-learn main::before,
  .page-lesson main::before {
    width: min(100%, 40rem);
  }
}
.page-learn .learn,
.page-lesson .lesson {
  position: relative;
  z-index: 1;
  padding-block: var(--space-md) var(--space-layout);
}

/* The overlay-note appears under the shortcuts list in chapter overlays */
.overlay-note {
  margin: var(--space-md) 0 0;
  font: 400 11px/1.4 var(--font-wordmark);
  letter-spacing: 0.02em;
  color: var(--text-tertiary);
  text-transform: lowercase;
  text-align: center;
}
.immersive #ambient,
.immersive.is-on ~ #ambient { opacity: 0.05; }

/* ── Onboarding (macOS-style window over the blurred page) ─────── */

/* Lock body scroll while the picker is open so the (blurred) page
 * underneath can't drift under wheel / touch / arrow keys. */
body:has(.picker:not([hidden])) { overflow: hidden; }

.picker {
  position: fixed;
  inset: 0;
  background: color-mix(in srgb, var(--chrome-background) 70%, transparent);
  backdrop-filter: blur(10px) saturate(120%);
  -webkit-backdrop-filter: blur(10px) saturate(120%);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: var(--space-lg);
  z-index: 20;
  animation: picker-fade-in 240ms var(--ease-standard);
}
.picker[hidden] { display: none; }
@keyframes picker-fade-in {
  from { opacity: 0; }
  to { opacity: 1; }
}

/* The window itself — a small, calm Mac app window */
.mac-window {
  background: var(--chrome-surface);
  border-radius: 12px;
  width: 100%;
  max-width: 480px;
  box-shadow:
    0 0 0 0.5px color-mix(in srgb, var(--text-primary) 14%, transparent),
    0 24px 64px -8px rgba(0, 0, 0, 0.32),
    0 8px 24px -4px rgba(0, 0, 0, 0.18);
  overflow: hidden;
  display: flex;
  flex-direction: column;
  animation: mac-rise 320ms var(--ease-standard);
}
@keyframes mac-rise {
  from { opacity: 0; transform: translateY(8px) scale(0.985); }
  to { opacity: 1; transform: translateY(0) scale(1); }
}
@media (prefers-reduced-motion: reduce) {
  .picker, .mac-window { animation: none; }
}

/* Title bar — traffic lights + centered subtitle */
.mac-titlebar {
  position: relative;
  height: 36px;
  display: flex;
  align-items: center;
  padding: 0 12px;
  border-bottom: 0.5px solid color-mix(in srgb, var(--text-primary) 10%, transparent);
  background: color-mix(in srgb, var(--chrome-surface) 92%, var(--text-primary) 2%);
  user-select: none;
}
.traffic-lights {
  display: inline-flex;
  align-items: center;
  gap: 8px;
}
.traffic-lights .tl {
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: #C8C8CC;
  border: 0.5px solid rgba(0, 0, 0, 0.10);
  display: inline-block;
  cursor: default;
  transition: background 120ms var(--ease-standard);
}
.mac-window:hover .traffic-lights .tl-red    { background: #FF5F57; }
.mac-window:hover .traffic-lights .tl-yellow { background: #FEBC2E; }
.mac-window:hover .traffic-lights .tl-green  { background: #28C840; }
.traffic-lights .tl-red {
  background: #FF5F57;
  cursor: pointer;
}
.traffic-lights .tl-red:hover { box-shadow: inset 0 0 0 1px rgba(0, 0, 0, 0.25); }
.mac-title {
  position: absolute;
  left: 50%;
  top: 50%;
  transform: translate(-50%, -50%);
  font: 400 12px/1 var(--font-wordmark);
  letter-spacing: 0.02em;
  color: var(--text-tertiary);
  text-transform: lowercase;
  pointer-events: none;
  white-space: nowrap;
  max-width: 60%;
  overflow: hidden;
  text-overflow: ellipsis;
}

/* Window body */
.mac-content {
  padding: 36px 36px 28px;
  min-height: 320px;
  display: flex;
  flex-direction: column;
}
@media (max-width: 480px) {
  .mac-content { padding: 28px 24px 20px; min-height: 280px; }
}

.onboard-step {
  display: flex;
  flex-direction: column;
  flex: 1;
  animation: step-in 240ms var(--ease-standard);
}
.onboard-step[hidden] { display: none; }
@keyframes step-in {
  from { opacity: 0; transform: translateY(4px); }
  to { opacity: 1; transform: translateY(0); }
}
@media (prefers-reduced-motion: reduce) {
  .onboard-step { animation: none; }
}

/* Step 1 — welcome */
.onboard-hero-icon {
  width: 56px;
  height: 56px;
  border-radius: var(--radius-icon);
  background: var(--icon-bg);
  color: var(--icon-fg);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  margin-bottom: var(--space-lg);
}
.onboard-hero-icon svg { width: 100%; height: 100%; display: block; }

.onboard-step h2 {
  margin: 0 0 10px;
  font: 600 22px/28px var(--font-display);
  letter-spacing: -0.01em;
  color: var(--text-primary);
  text-wrap: balance;
}
.onboard-step p {
  margin: 0;
  font: 400 15px/22px var(--font-chrome);
  color: var(--text-secondary);
  text-wrap: pretty;
}
.onboard-step p + p { margin-top: var(--space-md); }

/* Step 2 — what's inside (bullet list) */
.onboard-bullets {
  list-style: none;
  padding: 0;
  margin: var(--space-lg) 0 0;
  display: flex;
  flex-direction: column;
  gap: var(--space-md);
}
.onboard-bullets li {
  display: grid;
  grid-template-columns: 24px 1fr;
  gap: 12px;
  align-items: flex-start;
}
.onboard-bullets .bullet-icon {
  width: 24px;
  height: 24px;
  border-radius: 6px;
  background: color-mix(in srgb, var(--text-primary) 8%, transparent);
  color: var(--text-primary);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font: 500 12px/1 var(--font-wordmark);
  letter-spacing: 0;
  flex: 0 0 auto;
}
.onboard-bullets .bullet-body {
  font: 400 14px/20px var(--font-chrome);
  color: var(--text-primary);
}
.onboard-bullets .bullet-body .bullet-sub {
  display: block;
  margin-top: 2px;
  font-size: 13px;
  color: var(--text-tertiary);
}

/* Step 3 — choose mode (option cards) */
.picker-options {
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
  margin-top: var(--space-md);
}
.picker-options button {
  background: var(--button-surface);
  color: var(--button-text);
  border: 0;
  padding: 14px 16px;
  border-radius: 10px;
  font: 500 15px/1.2 var(--font-chrome);
  cursor: pointer;
  text-align: left;
  display: flex;
  flex-direction: column;
  gap: 4px;
  transition: transform 120ms var(--ease-standard), opacity 120ms var(--ease-standard);
}
.picker-options button:hover { opacity: 0.92; transform: translateY(-1px); }
.picker-options button:active { transform: translateY(0); }
.picker-options button[data-variant="secondary"] {
  background: color-mix(in srgb, var(--text-primary) 6%, transparent);
  color: var(--text-primary);
  outline: 0.5px solid color-mix(in srgb, var(--text-primary) 10%, transparent);
}
.picker-options .opt-title {
  font: 500 15px/1.2 var(--font-chrome);
}
.picker-options .opt-sub {
  font: 400 12px/1.4 var(--font-wordmark);
  opacity: 0.75;
  letter-spacing: 0.02em;
  text-transform: none;
}

/* Action row (primary CTA + ghost back/skip) */
.onboard-actions {
  margin-top: auto;
  padding-top: var(--space-xl);
  display: flex;
  align-items: center;
  gap: var(--space-md);
}
.onboard-actions .spacer { flex: 1; }
.onboard-cta {
  background: var(--button-surface);
  color: var(--button-text);
  border: 0;
  padding: 10px 18px;
  border-radius: 8px;
  font: 500 14px/1 var(--font-chrome);
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  min-height: 36px;
  transition: opacity 120ms var(--ease-standard);
}
.onboard-cta:hover { opacity: 0.9; }
.onboard-cta:focus-visible {
  outline: 2px solid var(--button-surface);
  outline-offset: 3px;
}
.onboard-ghost {
  background: none;
  border: 0;
  color: var(--text-tertiary);
  font: 400 12px/1 var(--font-wordmark);
  letter-spacing: 0.02em;
  cursor: pointer;
  text-transform: lowercase;
  padding: 8px 6px;
  border-radius: 4px;
}
.onboard-ghost:hover { color: var(--text-primary); }
.onboard-ghost:focus-visible {
  outline: 2px solid var(--text-primary);
  outline-offset: 2px;
}

/* Progress dots in the title bar's footer band */
.mac-progress {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 6px;
  padding: 0 0 18px;
}
.mac-progress .dot {
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: color-mix(in srgb, var(--text-primary) 16%, transparent);
  transition: background 200ms var(--ease-standard);
}
.mac-progress .dot.is-on {
  background: var(--text-primary);
}
.mac-progress .dot.is-done {
  background: color-mix(in srgb, var(--text-primary) 45%, transparent);
}

/* ── <shio-terminal> ───────────────────────────────────────────── */

shio-terminal {
  display: block;
  background: var(--term-bg);
  color: var(--term-fg);
  border: 1px solid var(--term-border);
  border-radius: 8px;
  padding: var(--space-lg) var(--space-lg) var(--space-md);
  font: 400 14px/1.6 ui-monospace, "SF Mono", Menlo, monospace;
  position: relative;
  min-height: 8em;
  max-height: 24em;
  overflow-y: auto;
  cursor: text;
  -webkit-overflow-scrolling: touch;
}
shio-terminal.is-compact {
  min-height: 6em;
  max-height: 14em;
  padding: var(--space-md);
  font-size: 13px;
}
shio-terminal.is-focused {
  border-color: color-mix(in srgb, var(--text-primary) 28%, transparent);
}
shio-terminal.is-checkpoint-complete {
  border-color: color-mix(in srgb, var(--text-primary) 50%, transparent);
}

.term-screen {
  white-space: pre-wrap;
  word-break: break-word;
}
.term-line {
  min-height: 1.6em;
}
.term-line.term-cmd { color: var(--term-stdin); }
.term-line.term-stdout { color: var(--term-stdout); }
.term-line.term-stderr { color: var(--term-stderr); }
.term-line.term-system { color: var(--term-stderr); font-style: italic; }

.term-input {
  display: inline-flex;
  flex-wrap: wrap;
  align-items: baseline;
  color: var(--term-stdin);
}
.term-prompt { color: var(--term-prompt); white-space: pre; }
.term-input-before,
.term-input-after { white-space: pre; }
.term-cursor {
  display: inline-block;
  width: 0.55em;
  height: 1em;
  background: currentColor;
  transform: translateY(0.12em);
  animation: blink 1.2s steps(2, end) infinite;
  margin: 0 0.02em;
}
/* Unfocused: dim the cursor instead of going hollow — easier to spot,
 * and the dim/solid contrast vs. the focused/blinking state still reads
 * as "click here to type." */
shio-terminal:not(.is-focused) .term-cursor {
  background: currentColor;
  opacity: 0.32;
  animation: none;
}
/* Soft "click to type" hint sitting after the input line, visible only
 * when the terminal is unfocused. Pure CSS — disappears the moment the
 * user clicks in or starts typing. */
shio-terminal::after {
  content: "click to type";
  position: absolute;
  right: var(--space-md);
  bottom: var(--space-sm);
  font: 400 11px/1 var(--font-wordmark);
  letter-spacing: 0.02em;
  color: var(--text-tertiary);
  opacity: 0.55;
  text-transform: lowercase;
  pointer-events: none;
  user-select: none;
  transition: opacity 120ms var(--ease-standard);
}
shio-terminal.is-focused::after { opacity: 0; }
@media (prefers-reduced-motion: reduce) {
  .term-cursor { animation: none; opacity: 0.6; }
}

.term-hidden-input {
  position: absolute;
  opacity: 0;
  pointer-events: none;
  width: 1px;
  height: 1px;
  border: 0;
  padding: 0;
  margin: 0;
  left: -9999px;
}

/* The terminal becomes a real input target on touch */
@media (pointer: coarse) {
  shio-terminal {
    max-height: 50vh;
  }
}

/* ── <shio-keyboard> ───────────────────────────────────────────── */

shio-keyboard {
  display: none;
  position: sticky;
  bottom: 0;
  left: 0;
  right: 0;
  z-index: 5;
  background: var(--chrome-background);
  border-top: 1px solid var(--term-border);
  padding: 6px max(10px, env(safe-area-inset-right))
          calc(6px + env(safe-area-inset-bottom, 0))
          max(10px, env(safe-area-inset-left));
  user-select: none;
  -webkit-user-select: none;
}
@media (pointer: coarse) {
  shio-keyboard { display: block; }
}
.page-learn shio-keyboard.is-shown { display: block; }

.kbd-scroller {
  display: flex;
  align-items: center;
  gap: 6px;
  overflow-x: auto;
  scrollbar-width: none;
  -webkit-overflow-scrolling: touch;
}
.kbd-scroller::-webkit-scrollbar { display: none; }

.kbd-key {
  flex: 0 0 auto;
  min-width: 32px;
  height: 34px;
  padding: 0 10px;
  border: 0;
  border-radius: 6px;
  background: var(--keycap-bg);
  color: var(--keycap-fg);
  font: 500 15px/1 var(--font-wordmark);
  letter-spacing: 0.02em;
  text-transform: lowercase;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  transition: background 60ms var(--ease-standard), color 60ms var(--ease-standard);
  touch-action: manipulation;
}
.kbd-key.is-down { background: var(--keycap-down-bg); }
.kbd-key.is-pending {
  background: var(--keycap-pending-bg);
  color: var(--keycap-pending-fg);
}
.kbd-key.is-locked {
  background: var(--keycap-locked-bg);
  color: var(--keycap-locked-fg);
}
.kbd-sep {
  flex: 0 0 auto;
  width: 1px;
  height: 22px;
  background: color-mix(in srgb, var(--text-primary) 18%, transparent);
}

/* ── Lesson page layout ────────────────────────────────────────── */

.lesson {
  max-width: 36rem;
  width: 100%;
  margin: 0 auto;
  padding: 0 var(--space-lg);
}
@media (min-width: 640px) {
  .lesson {
    max-width: 38rem;
    padding: 0 var(--space-xl);
  }
}

.page-lesson main {
  display: block;
  padding: 0;
  width: 100%;
}

.lesson-hero {
  margin-top: var(--space-xl);
}
.lesson-eyebrow {
  margin: 0 0 var(--space-sm);
  font: 400 12px/1.4 var(--font-wordmark);
  letter-spacing: 0.04em;
  color: var(--text-tertiary);
  text-transform: lowercase;
}
.lesson-hero h1 {
  margin: 0 0 var(--space-md);
  font: 600 30px/38px var(--font-display);
  letter-spacing: -0.02em;
  color: var(--text-primary);
  text-wrap: balance;
}
.lesson-sub {
  margin: 0;
  font: 400 17px/26px var(--font-chrome);
  color: var(--text-secondary);
  text-wrap: pretty;
}
@media (min-width: 640px) {
  .lesson-hero h1 { font-size: 34px; line-height: 42px; }
  .lesson-sub { font-size: 18px; line-height: 28px; }
}

.lesson-section + .lesson-section { margin-top: var(--space-xxxl); }
.lesson-section {
  margin-top: var(--space-xxl);
}
.lesson-section h2 {
  margin: 0 0 var(--space-md);
  font: 400 16px/22px var(--font-wordmark);
  letter-spacing: 0.02em;
  color: var(--text-primary);
  text-transform: lowercase;
  display: flex;
  align-items: baseline;
  gap: 0.4em;
}
.lesson-section h2 .prompt-sigil { color: var(--text-tertiary); }

.lesson-section p,
.lesson-section ol,
.lesson-section ul {
  margin: 0;
  font: 400 16px/26px var(--font-chrome);
  color: var(--text-primary);
}
.lesson-section p + p,
.lesson-section p + ol,
.lesson-section ol + p,
.lesson-section p + ul,
.lesson-section ul + p { margin-top: var(--space-lg); }
.lesson-section p + shio-terminal,
.lesson-section shio-terminal + p,
.lesson-section h2 + shio-terminal,
.lesson-section ul + shio-terminal,
.lesson-section ol + shio-terminal { margin-top: var(--space-xl); }
.lesson-section code {
  font-family: ui-monospace, "SF Mono", Menlo, monospace;
  font-size: 0.9em;
  padding: 1px 5px;
  border-radius: 4px;
  background: color-mix(in srgb, var(--text-primary) 8%, transparent);
  color: var(--text-primary);
}
@media (min-width: 640px) {
  .lesson-section p,
  .lesson-section ol,
  .lesson-section ul { font-size: 17px; line-height: 28px; }
}

.try-it {
  margin-top: var(--space-md);
  font: 400 12px/1.6 var(--font-wordmark);
  color: var(--text-tertiary);
  letter-spacing: 0.02em;
  text-transform: lowercase;
  display: flex;
  align-items: center;
  gap: 0.4em;
}
.try-it .prompt-sigil { color: var(--text-tertiary); }
.try-it.is-complete::after {
  content: "✓ done";
  margin-left: auto;
  color: var(--text-primary);
}

/* Lesson nav (prev/next + progress dots) */
.lesson-nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-md);
  margin: var(--space-xxxl) 0 var(--space-xxl);
  font: 400 13px/1.4 var(--font-wordmark);
  letter-spacing: 0.02em;
  text-transform: lowercase;
}
.lesson-nav a {
  color: var(--text-primary);
  text-decoration-color: color-mix(in srgb, currentColor 30%, transparent);
}
.lesson-nav .spacer { flex: 1; }
.lesson-nav-dots {
  display: inline-flex;
  gap: 4px;
  align-items: center;
}
.lesson-nav-dots span {
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: color-mix(in srgb, var(--text-primary) 18%, transparent);
}
.lesson-nav-dots span.is-current { background: var(--text-primary); }
.lesson-nav-dots span.is-done { background: color-mix(in srgb, var(--text-primary) 55%, transparent); }

/* Mode-switch footer button (matches theme toggle aesthetic) */
.mode-switch {
  background: none;
  border: 0;
  cursor: pointer;
  color: var(--text-tertiary);
  font: 400 11px/1 var(--font-wordmark);
  letter-spacing: 0.02em;
  text-transform: lowercase;
  padding: 6px 8px;
  border-radius: 6px;
}
.mode-switch:hover { color: var(--text-primary); }

/* ── Immersive mode (full-screen sandbox on /learn/) ──────────── */

.immersive {
  position: fixed;
  inset: 0;
  /* mostly opaque so terminal text stays crisp, but a touch translucent
   * so the ambient sky/ocean keeps living behind it */
  background: color-mix(in srgb, var(--chrome-background) 94%, transparent);
  backdrop-filter: blur(1px);
  -webkit-backdrop-filter: blur(1px);
  display: none;
  flex-direction: column;
  z-index: 8;
}
.immersive.is-on { display: flex; }
.immersive-bar {
  display: flex;
  align-items: center;
  gap: var(--space-md);
  padding: var(--space-md) var(--space-lg);
  border-bottom: 1px solid var(--term-border);
  font: 400 12px/1.4 var(--font-wordmark);
  color: var(--text-tertiary);
  letter-spacing: 0.02em;
  text-transform: lowercase;
}
.immersive-bar .prompt-path { color: var(--text-secondary); }
.immersive-bar .spacer { flex: 1; }
.immersive-bar button {
  background: none;
  border: 0;
  color: var(--text-tertiary);
  font: inherit;
  cursor: pointer;
  padding: 4px 8px;
  border-radius: 4px;
  text-transform: lowercase;
}
.immersive-bar button:hover { color: var(--text-primary); }
.immersive-main {
  flex: 1;
  display: flex;
  flex-direction: column;
  padding: var(--space-lg);
  overflow: hidden;
}
.immersive-main shio-terminal {
  flex: 1;
  max-height: none;
  border: 0;
  background: transparent;
  padding: 0;
  font-size: 14px;
}
@media (min-width: 640px) {
  .immersive-main shio-terminal { font-size: 15px; }
}