:root {
  color-scheme: light dark;
  --paper: #f4f6f3;
  --surface: #ffffff;
  --surface-soft: #eef2ef;
  --ink: #17231f;
  --muted: #596761;
  --line: #cbd3cf;
  --line-strong: #9eaaa4;
  --primary: #c54530;
  --primary-strong: #96301f;
  --teal: #176a61;
  --teal-soft: #e1f0ec;
  --amber: #b8750b;
  --amber-soft: #fbefd9;
  --danger: #a72f26;
  --danger-soft: #f9e5df;
  --code-bg: #16221f;
  --code-ink: #edf6f2;
  --focus: #087f8c;
  --shadow: 0 14px 40px rgba(23, 35, 31, 0.12);
  --grid-line: rgba(23, 35, 31, 0.035);
  --radius: 8px;
  font-family: "Avenir Next", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  font-synthesis: none;
}

:root[data-theme="light"] {
  color-scheme: light;
  --paper: #f7f9f7;
  --surface: #ffffff;
  --surface-soft: #edf3f0;
  --ink: #14211d;
  --muted: #4c5d55;
  --line: #c2cfca;
  --line-strong: #8fa39a;
  --primary: #b93826;
  --primary-strong: #8e291c;
  --teal: #075f58;
  --teal-soft: #dcefe9;
  --code-bg: #172622;
  --code-ink: #f1faf6;
  --grid-line: rgba(20, 33, 29, 0.045);
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    color-scheme: dark;
    --paper: #101613;
    --surface: #18211d;
    --surface-soft: #202b26;
    --ink: #edf3ef;
    --muted: #abb8b1;
    --line: #394740;
    --line-strong: #58665f;
    --primary: #ed7862;
    --primary-strong: #ff9b88;
    --teal: #65c6b8;
    --teal-soft: #193b35;
    --amber: #e3a94b;
    --amber-soft: #3b301d;
    --danger: #ff8f83;
    --danger-soft: #412620;
    --code-bg: #0b100e;
    --code-ink: #edf6f2;
    --focus: #5fd6e2;
    --shadow: 0 14px 40px rgba(0, 0, 0, 0.34);
    --grid-line: rgba(237, 243, 239, 0.035);
  }
}

:root[data-theme="dark"] {
  color-scheme: dark;
  --paper: #101613;
  --surface: #18211d;
  --surface-soft: #202b26;
  --ink: #edf3ef;
  --muted: #abb8b1;
  --line: #394740;
  --line-strong: #58665f;
  --primary: #ed7862;
  --primary-strong: #ff9b88;
  --teal: #65c6b8;
  --teal-soft: #193b35;
  --amber: #e3a94b;
  --amber-soft: #3b301d;
  --danger: #ff8f83;
  --danger-soft: #412620;
  --code-bg: #0b100e;
  --code-ink: #edf6f2;
  --focus: #5fd6e2;
  --shadow: 0 14px 40px rgba(0, 0, 0, 0.34);
  --grid-line: rgba(237, 243, 239, 0.035);
}

* {
  box-sizing: border-box;
}

html {
  background: var(--paper);
  scroll-behavior: smooth;
}

body {
  min-width: 320px;
  margin: 0;
  color: var(--ink);
  background-color: var(--paper);
  background-image:
    linear-gradient(var(--grid-line) 1px, transparent 1px),
    linear-gradient(90deg, var(--grid-line) 1px, transparent 1px);
  background-size: 28px 28px;
  letter-spacing: 0;
}

button,
input,
select,
textarea {
  font: inherit;
  letter-spacing: 0;
}

button,
select,
label[for] {
  -webkit-tap-highlight-color: transparent;
}

button {
  color: inherit;
}

a {
  color: var(--teal);
}

:focus-visible {
  outline: 3px solid color-mix(in srgb, var(--focus) 70%, transparent);
  outline-offset: 3px;
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.skip-link {
  position: fixed;
  z-index: 100;
  top: 10px;
  left: 10px;
  padding: 10px 14px;
  color: var(--surface);
  background: var(--ink);
  border-radius: 4px;
  transform: translateY(-160%);
}

.skip-link:focus {
  transform: translateY(0);
}

.topbar {
  position: sticky;
  z-index: 30;
  top: 0;
  display: grid;
  grid-template-columns: minmax(210px, 1fr) auto auto;
  align-items: center;
  gap: 24px;
  min-height: 70px;
  padding: 10px clamp(16px, 3vw, 42px);
  background: color-mix(in srgb, var(--surface) 94%, transparent);
  border-bottom: 1px solid var(--line);
  backdrop-filter: blur(14px);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  width: fit-content;
  color: var(--ink);
  text-decoration: none;
}

.brand-mark {
  display: grid;
  flex: 0 0 40px;
  width: 40px;
  height: 40px;
  place-items: center;
  color: var(--surface);
  background: var(--ink);
  border-radius: 6px;
  font-family: "SFMono-Regular", Consolas, monospace;
  font-size: 14px;
  font-weight: 700;
}

.brand-copy {
  display: grid;
  gap: 1px;
}

.brand-copy strong {
  font-size: 15px;
  font-weight: 700;
}

.brand-copy span {
  color: var(--muted);
  font-size: 12px;
}

.top-status {
  display: grid;
  gap: 1px;
  text-align: right;
}

.top-status > span:first-child {
  font-family: "SFMono-Regular", Consolas, monospace;
  font-size: 13px;
  font-weight: 700;
}

.save-status {
  color: var(--muted);
  font-size: 11px;
}

.top-actions {
  display: flex;
  gap: 6px;
}

.icon-text-button,
.icon-button,
.primary-button,
.secondary-button,
.danger-button,
.step-action,
.day-button,
.step-tab,
.quiz-option,
.confidence-button,
.flow-stage,
.token-button {
  border: 0;
  cursor: pointer;
}

.icon-text-button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  min-height: 44px;
  padding: 0 11px;
  background: transparent;
  border-radius: 6px;
  font-size: 13px;
}

.icon-text-button:hover {
  background: var(--surface-soft);
}

.icon-text-button > span:first-child {
  min-width: 18px;
  font-family: "SFMono-Regular", Consolas, monospace;
  font-weight: 700;
  text-align: center;
}

.overall-progress {
  position: sticky;
  z-index: 31;
  top: 69px;
  height: 3px;
  background: var(--line);
}

.overall-progress span {
  display: block;
  width: 0;
  height: 100%;
  background: var(--primary);
  transition: width 220ms ease;
}

.learning-shell {
  display: grid;
  grid-template-columns: 280px minmax(0, 900px);
  align-items: start;
  gap: clamp(30px, 5vw, 72px);
  max-width: 1320px;
  min-height: calc(100vh - 73px);
  margin: 0 auto;
  padding: 34px clamp(18px, 4vw, 56px) 80px;
}

.course-rail {
  position: sticky;
  top: 104px;
  max-height: calc(100vh - 126px);
  overflow: auto;
  scrollbar-width: thin;
}

.rail-heading {
  display: flex;
  align-items: end;
  justify-content: space-between;
  gap: 16px;
  padding: 0 4px 14px;
  border-bottom: 2px solid var(--ink);
}

.rail-heading span,
.section-kicker,
.step-kicker {
  color: var(--primary);
  font-size: 11px;
  font-weight: 800;
  letter-spacing: 0;
  text-transform: uppercase;
}

.rail-heading strong {
  font-family: "SFMono-Regular", Consolas, monospace;
  font-size: 12px;
}

.day-list {
  display: grid;
}

.day-button {
  display: grid;
  grid-template-columns: 38px minmax(0, 1fr) auto;
  align-items: center;
  gap: 10px;
  min-height: 66px;
  padding: 10px 4px;
  text-align: left;
  background: transparent;
  border-bottom: 1px solid var(--line);
}

.day-button:hover {
  background: color-mix(in srgb, var(--teal-soft) 55%, transparent);
}

.day-button[aria-current="true"] {
  background: var(--surface);
  box-shadow: inset 4px 0 0 var(--primary);
}

.day-number {
  font-family: "SFMono-Regular", Consolas, monospace;
  font-size: 20px;
  font-weight: 700;
  text-align: center;
}

.day-label {
  display: grid;
  gap: 2px;
  min-width: 0;
}

.day-label strong {
  overflow: hidden;
  font-size: 13px;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.day-label span,
.day-state {
  color: var(--muted);
  font-size: 11px;
}

.day-state {
  white-space: nowrap;
}

.day-button.is-complete .day-number,
.day-button.is-complete .day-state {
  color: var(--teal);
}

.mobile-day-picker {
  display: none;
}

.rail-note {
  margin: 18px 4px 0;
  color: var(--muted);
  font-size: 12px;
  line-height: 1.6;
}

.lesson {
  min-width: 0;
  scroll-margin-top: 90px;
}

.lesson-header {
  padding-bottom: 24px;
  border-bottom: 2px solid var(--ink);
}

.lesson-heading-row {
  display: flex;
  align-items: start;
  justify-content: space-between;
  gap: 24px;
}

.lesson-header h1 {
  max-width: 720px;
  margin: 8px 0 12px;
  font-size: 36px;
  line-height: 1.15;
  letter-spacing: 0;
}

.lesson-outcome {
  max-width: 720px;
  margin: 0;
  color: var(--muted);
  font-size: 16px;
  line-height: 1.7;
}

.review-toggle {
  flex: 0 0 auto;
  min-height: 44px;
  padding: 0 12px;
  color: var(--muted);
  background: transparent;
  border: 1px solid var(--line);
  border-radius: 6px;
  cursor: pointer;
}

.review-toggle[aria-pressed="true"] {
  color: var(--surface);
  background: var(--amber);
  border-color: var(--amber);
}

.lesson-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 18px;
  margin-top: 18px;
  color: var(--muted);
  font-family: "SFMono-Regular", Consolas, monospace;
  font-size: 12px;
}

.step-tabs {
  display: grid;
  grid-template-columns: repeat(6, minmax(0, 1fr));
  gap: 0;
  margin: 26px 0 0;
  border-bottom: 1px solid var(--line);
}

.step-tab {
  position: relative;
  display: grid;
  min-width: 0;
  min-height: 58px;
  place-content: center;
  gap: 2px;
  padding: 8px 4px 12px;
  color: var(--muted);
  text-align: center;
  background: transparent;
}

.step-tab::after {
  position: absolute;
  right: 0;
  bottom: -1px;
  left: 0;
  height: 3px;
  content: "";
  background: transparent;
}

.step-tab:hover {
  color: var(--ink);
  background: color-mix(in srgb, var(--surface) 55%, transparent);
}

.step-tab[aria-current="step"] {
  color: var(--ink);
}

.step-tab[aria-current="step"]::after {
  background: var(--primary);
}

.step-tab.is-complete::before {
  position: absolute;
  top: 7px;
  right: 9px;
  color: var(--teal);
  content: "✓";
  font-weight: 800;
}

.step-tab-number {
  font-family: "SFMono-Regular", Consolas, monospace;
  font-size: 11px;
  font-weight: 700;
}

.step-tab-label {
  overflow: hidden;
  font-size: 12px;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.lesson-step {
  min-height: 500px;
  padding: 44px 0 22px;
  scroll-margin-top: 82px;
}

.lesson-step h2 {
  max-width: 760px;
  margin: 8px 0 22px;
  font-size: 28px;
  line-height: 1.3;
  letter-spacing: 0;
}

#current-day-title:focus-visible,
#current-step-title:focus-visible {
  outline: 3px solid var(--focus);
  outline-offset: 5px;
}

.step-time {
  float: right;
  margin-top: 2px;
  color: var(--muted);
  font-family: "SFMono-Regular", Consolas, monospace;
  font-size: 12px;
}

.prose {
  max-width: 760px;
}

.prose p,
.task-block p,
.question-feedback p,
.recap-block p,
.dialog-body p {
  line-height: 1.75;
}

.prose p {
  margin: 0 0 14px;
  font-size: 16px;
}

.key-list {
  display: grid;
  gap: 10px;
  max-width: 760px;
  padding: 0;
  margin: 22px 0;
  list-style: none;
}

.key-list li {
  position: relative;
  padding-left: 24px;
  line-height: 1.65;
}

.key-list li::before {
  position: absolute;
  top: 0.7em;
  left: 2px;
  width: 8px;
  height: 8px;
  content: "";
  background: var(--teal);
  border-radius: 1px;
  transform: translateY(-50%) rotate(45deg);
}

.concept-map {
  max-width: 820px;
  margin: 28px 0;
  border-top: 2px solid var(--ink);
}

.mapping-row {
  display: grid;
  grid-template-columns: minmax(120px, 0.8fr) minmax(220px, 1.5fr) minmax(220px, 1.4fr);
  gap: 18px;
  align-items: start;
  padding: 15px 4px;
  border-bottom: 1px solid var(--line);
}

.mapping-row strong {
  font-size: 14px;
}

.mapping-row span {
  color: var(--muted);
  font-size: 14px;
  line-height: 1.55;
}

.mapping-row code {
  overflow-wrap: anywhere;
  color: var(--teal);
  font-family: "SFMono-Regular", Consolas, monospace;
  font-size: 12px;
}

.math-block,
.task-block,
.recap-block {
  max-width: 820px;
  margin: 28px 0;
  padding: 18px 20px;
  border-left: 4px solid var(--amber);
  background: var(--amber-soft);
}

.math-block summary {
  cursor: pointer;
  font-weight: 700;
}

.math-block p:last-child,
.task-block p:last-child,
.recap-block p:last-child {
  margin-bottom: 0;
}

.math-example {
  font-family: "SFMono-Regular", Consolas, monospace;
  font-size: 13px;
}

.task-block {
  border-left-color: var(--teal);
  background: var(--teal-soft);
}

.task-block h3,
.recap-block h3 {
  margin: 0 0 8px;
  font-size: 16px;
}

.task-observe {
  color: var(--muted);
  font-size: 14px;
}

.code-shell {
  max-width: 860px;
  margin: 28px 0;
  overflow: hidden;
  background: var(--code-bg);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

.code-toolbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  min-height: 46px;
  padding: 6px 10px 6px 16px;
  color: #bed0c9;
  border-bottom: 1px solid rgba(255, 255, 255, 0.12);
}

.code-toolbar code {
  min-width: 0;
  overflow: hidden;
  font-size: 12px;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.code-description {
  display: flex;
  min-width: 0;
  align-items: center;
  gap: 8px;
}

.code-run-status {
  flex: 0 0 auto;
  padding-left: 8px;
  color: #d6e5df;
  border-left: 1px solid rgba(255, 255, 255, 0.22);
  font-size: 11px;
  font-weight: 700;
  line-height: 1.35;
}

.code-run-status.is-runnable {
  color: #a9e8cf;
}

.code-run-status.is-fragment {
  color: #f4d79a;
}

.code-actions {
  display: flex;
  gap: 6px;
}

.code-button {
  min-height: 34px;
  padding: 0 10px;
  color: var(--code-ink);
  background: transparent;
  border: 1px solid rgba(255, 255, 255, 0.22);
  border-radius: 5px;
  cursor: pointer;
  font-size: 12px;
}

.code-button:hover {
  background: rgba(255, 255, 255, 0.08);
}

pre {
  margin: 0;
  overflow-x: auto;
}

.code-shell pre code {
  display: block;
  min-width: max-content;
  padding: 20px;
  color: var(--code-ink);
  font-family: "SFMono-Regular", Consolas, monospace;
  font-size: 13px;
  line-height: 1.65;
}

.output-block {
  padding: 16px 20px;
  color: #d6e5df;
  background: #23332f;
  border-top: 1px solid rgba(255, 255, 255, 0.12);
  font-family: "SFMono-Regular", Consolas, monospace;
  font-size: 12px;
  line-height: 1.6;
  white-space: pre-wrap;
}

.exercise-runner {
  max-width: 860px;
  margin: 28px 0;
  padding: 20px;
  background: var(--surface-soft);
  border: 1px solid var(--line-strong);
  border-top: 4px solid var(--teal);
  border-radius: var(--radius);
}

.runner-heading {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 16px;
}

.runner-heading h3 {
  margin: 4px 0 0;
  font-size: 18px;
}

.runner-kicker,
.runner-safety {
  color: var(--teal);
  font-size: 12px;
  font-weight: 700;
}

.runner-safety {
  flex: 0 0 auto;
  padding: 5px 8px;
  background: var(--teal-soft);
  border-radius: 4px;
}

.runner-hint,
.runner-status {
  color: var(--muted);
  font-size: 13px;
  line-height: 1.6;
}

.runner-controls {
  display: grid;
  grid-template-columns: minmax(160px, 1fr) minmax(140px, 1fr) auto auto;
  align-items: end;
  gap: 10px;
  margin: 16px 0 10px;
}

.runner-controls label {
  display: grid;
  gap: 5px;
  font-size: 13px;
  font-weight: 700;
}

.runner-controls label code {
  color: var(--muted);
  font-size: 11px;
  font-weight: 400;
}

.runner-controls input {
  width: 100%;
  min-height: 42px;
  padding: 8px 10px;
  color: var(--ink);
  background: var(--surface);
  border: 1px solid var(--line-strong);
  border-radius: 5px;
}

.runner-controls button {
  min-height: 42px;
  white-space: nowrap;
}

.runner-status code {
  display: inline-block;
  margin-left: 6px;
  color: var(--ink);
}

.runner-output {
  min-height: 132px;
  max-height: 360px;
  margin-top: 12px;
  padding: 14px;
  overflow: auto;
  color: #d6e5df;
  background: var(--code-bg);
  border-radius: 5px;
  font-family: "SFMono-Regular", Consolas, monospace;
  font-size: 12px;
  line-height: 1.6;
  white-space: pre-wrap;
}

.runner-output.is-error {
  color: #ffd2c9;
}

.runner-review-button {
  margin-top: 10px;
  min-height: 38px;
}

.tutor-expansion {
  display: flex;
  max-width: 860px;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  margin: 26px 0;
  padding: 16px 0;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.tutor-expansion > div {
  display: grid;
  gap: 4px;
}

.tutor-expansion strong {
  font-size: 14px;
}

.tutor-expansion span {
  color: var(--muted);
  font-size: 13px;
}

.tutor-expansion button[aria-expanded="true"] {
  color: var(--surface);
  background: var(--ink);
  border-color: var(--ink);
}

.question-block {
  max-width: 820px;
  margin: 28px 0;
  padding-top: 20px;
  border-top: 2px solid var(--ink);
}

.question-prompt {
  margin: 0 0 18px;
  font-size: 18px;
  font-weight: 700;
  line-height: 1.55;
}

.teach-entry {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px 14px;
  margin-bottom: 16px;
}

.teach-entry p {
  margin: 0;
  color: var(--muted);
  font-size: 13px;
}

.teach-button {
  min-height: 44px;
  padding: 0 14px;
  color: var(--primary-strong);
  background: var(--danger-soft);
  border: 1px solid color-mix(in srgb, var(--primary) 55%, var(--line));
  border-radius: 6px;
  cursor: pointer;
  font-weight: 700;
}

.teach-button:hover,
.teach-button[aria-expanded="true"] {
  color: var(--surface);
  background: var(--primary);
  border-color: var(--primary);
}

.slow-teaching {
  margin: 0 0 20px;
  padding: 20px;
  background: var(--amber-soft);
  border-left: 4px solid var(--amber);
}

.slow-teaching h3 {
  margin: 0 0 12px;
  font-size: 16px;
}

.slow-teaching ol {
  display: grid;
  gap: 10px;
  padding-left: 24px;
  margin: 0;
}

.slow-teaching li {
  padding-left: 4px;
  line-height: 1.7;
}

.slow-teaching-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 18px;
  padding-top: 14px;
  border-top: 1px solid color-mix(in srgb, var(--amber) 35%, transparent);
}

.quiz-options {
  display: grid;
  gap: 10px;
}

.quiz-option {
  display: grid;
  grid-template-columns: 34px minmax(0, 1fr);
  align-items: center;
  gap: 10px;
  min-height: 54px;
  padding: 8px 14px;
  text-align: left;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 6px;
}

.quiz-option:hover {
  border-color: var(--line-strong);
}

.quiz-option[aria-pressed="true"] {
  border-color: var(--ink);
  box-shadow: inset 4px 0 0 var(--ink);
}

.quiz-option.is-correct {
  border-color: var(--teal);
  box-shadow: inset 4px 0 0 var(--teal);
}

.quiz-option.is-wrong {
  border-color: var(--primary);
  box-shadow: inset 4px 0 0 var(--primary);
}

.option-letter {
  display: grid;
  width: 28px;
  height: 28px;
  place-items: center;
  background: var(--surface-soft);
  border-radius: 4px;
  font-family: "SFMono-Regular", Consolas, monospace;
  font-size: 12px;
  font-weight: 700;
}

.question-feedback {
  margin-top: 14px;
  padding: 14px 16px;
  background: var(--surface-soft);
  border-left: 4px solid var(--line-strong);
}

.question-feedback.is-correct {
  background: var(--teal-soft);
  border-left-color: var(--teal);
}

.question-feedback.is-wrong {
  background: var(--danger-soft);
  border-left-color: var(--primary);
}

.question-feedback p {
  margin: 0;
}

.micro-example {
  margin-top: 10px !important;
  color: var(--muted);
  font-size: 14px;
}

.lab {
  max-width: 860px;
  margin: 30px 0;
  padding: 22px;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: 0 10px 30px rgba(23, 35, 31, 0.08);
}

.lab-header {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 14px;
  margin-bottom: 20px;
}

.lab-header h3 {
  margin: 0;
  font-size: 16px;
}

.lab-header span {
  color: var(--muted);
  font-family: "SFMono-Regular", Consolas, monospace;
  font-size: 12px;
}

.tensor-diagram {
  display: grid;
  grid-template-columns: minmax(180px, 1fr) 64px minmax(180px, 1fr);
  align-items: center;
  gap: 18px;
}

.tensor-inputs,
.tensor-outputs {
  display: grid;
  gap: 14px;
}

.range-row {
  display: grid;
  grid-template-columns: 34px minmax(80px, 1fr) 46px;
  align-items: center;
  gap: 10px;
}

.range-row label,
.range-row .range-label,
.range-value {
  font-family: "SFMono-Regular", Consolas, monospace;
  font-size: 12px;
}

input[type="range"] {
  width: 100%;
  accent-color: var(--primary);
}

.tensor-arrow {
  display: grid;
  gap: 4px;
  place-items: center;
  color: var(--muted);
  font-family: "SFMono-Regular", Consolas, monospace;
  text-align: center;
}

.tensor-arrow strong {
  color: var(--ink);
  font-size: 22px;
}

.output-value {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  min-height: 48px;
  padding: 9px 12px;
  background: var(--surface-soft);
  border-left: 4px solid var(--teal);
}

.output-value strong,
.shape-chip {
  font-family: "SFMono-Regular", Consolas, monospace;
}

.shape-chip {
  display: inline-flex;
  align-items: center;
  min-height: 28px;
  padding: 0 8px;
  color: var(--teal);
  background: var(--teal-soft);
  border-radius: 4px;
  font-size: 11px;
  font-weight: 700;
}

.model-lab-layout {
  display: grid;
  gap: 20px;
}

.model-nodes,
.token-stages,
.pipeline-stages {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 12px;
}

.model-node,
.token-stage,
.pipeline-stage {
  position: relative;
  min-height: 86px;
  padding: 14px;
  background: var(--surface-soft);
  border-top: 4px solid var(--line-strong);
}

.model-node.active,
.token-stage.active,
.pipeline-stage.active {
  border-top-color: var(--teal);
}

.model-node strong,
.token-stage strong,
.pipeline-stage strong {
  display: block;
  margin-bottom: 6px;
  font-size: 13px;
}

.model-node span,
.token-stage span,
.pipeline-stage span {
  color: var(--muted);
  font-family: "SFMono-Regular", Consolas, monospace;
  font-size: 11px;
}

.model-control {
  display: grid;
  grid-template-columns: 150px minmax(120px, 1fr) 150px;
  align-items: center;
  gap: 12px;
}

.model-control label,
.model-total {
  font-size: 13px;
}

.weight-equation {
  display: grid;
  grid-template-columns: minmax(120px, 1fr) auto minmax(180px, 1.4fr) auto minmax(120px, 1fr);
  align-items: center;
  gap: 14px;
}

.weight-control {
  display: grid;
  gap: 10px;
}

.weight-control label {
  font-size: 13px;
  font-weight: 700;
}

.equation-symbol {
  color: var(--muted);
  font-family: "SFMono-Regular", Consolas, monospace;
  font-size: 20px;
  font-weight: 700;
}

.model-total {
  text-align: right;
}

.flow-stage-list {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.flow-stage {
  min-height: 44px;
  padding: 0 12px;
  color: var(--muted);
  background: var(--surface-soft);
  border-radius: 5px;
}

.flow-stage[aria-pressed="true"] {
  color: var(--surface);
  background: var(--ink);
}

.flow-detail {
  display: grid;
  grid-template-columns: minmax(110px, 0.6fr) minmax(200px, 1.4fr);
  gap: 20px;
  margin-top: 18px;
  padding-top: 18px;
  border-top: 1px solid var(--line);
}

.flow-shape {
  color: var(--teal);
  font-family: "SFMono-Regular", Consolas, monospace;
  font-size: 13px;
  font-weight: 700;
}

.flow-copy {
  line-height: 1.65;
}

.token-input {
  display: grid;
  gap: 8px;
  margin-bottom: 18px;
}

.token-input label {
  display: grid;
  gap: 8px;
  font-size: 13px;
  font-weight: 700;
}

.token-input input,
.search-field input,
.recap-note {
  width: 100%;
  min-height: 46px;
  padding: 10px 12px;
  color: var(--ink);
  background: var(--surface);
  border: 1px solid var(--line-strong);
  border-radius: 5px;
}

.token-list {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  min-height: 42px;
  margin-top: 10px;
}

.token-chip {
  display: inline-grid;
  min-width: 42px;
  min-height: 42px;
  place-items: center;
  padding: 4px 8px;
  background: var(--surface-soft);
  border-bottom: 3px solid var(--teal);
  font-family: "SFMono-Regular", Consolas, monospace;
  font-size: 12px;
}

.attention-tokens {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 8px;
}

.token-button {
  min-height: 48px;
  background: var(--surface-soft);
  border-radius: 5px;
}

.token-button[aria-pressed="true"] {
  color: var(--surface);
  background: var(--ink);
}

.attention-bars {
  display: grid;
  gap: 12px;
  margin-top: 20px;
}

.attention-row {
  display: grid;
  grid-template-columns: 44px minmax(100px, 1fr) 54px;
  align-items: center;
  gap: 10px;
}

.attention-bar-track {
  height: 16px;
  overflow: hidden;
  background: var(--surface-soft);
  border-radius: 3px;
}

.attention-bar-fill {
  height: 100%;
  background: var(--teal);
  transition: width 180ms ease;
}

.attention-row.is-masked {
  color: var(--muted);
}

.attention-row.is-masked .attention-bar-track {
  background: repeating-linear-gradient(135deg, var(--surface-soft) 0 7px, var(--line) 7px 9px);
}

.attention-percent {
  font-family: "SFMono-Regular", Consolas, monospace;
  font-size: 12px;
  text-align: right;
}

.recap-block {
  border-left-color: var(--primary);
  background: var(--danger-soft);
}

.confidence-group {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 8px;
  margin-top: 18px;
}

.confidence-button {
  min-height: 48px;
  padding: 8px 10px;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 5px;
}

.confidence-button[aria-pressed="true"] {
  color: var(--surface);
  background: var(--primary);
  border-color: var(--primary);
}

.recap-note {
  min-height: 86px;
  margin-top: 12px;
  resize: vertical;
}

.step-completion {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
  max-width: 860px;
  margin-top: 34px;
  padding-top: 22px;
  border-top: 1px solid var(--line);
}

.step-completion p {
  max-width: 520px;
  margin: 0;
  color: var(--muted);
  font-size: 13px;
  line-height: 1.55;
}

.completion-actions {
  display: flex;
  flex-wrap: wrap;
  justify-content: flex-end;
  gap: 8px;
}

.continue-button {
  white-space: nowrap;
}

.primary-button,
.secondary-button,
.danger-button,
.step-action {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 0 16px;
  border-radius: 6px;
  font-weight: 700;
}

.primary-button,
.step-action {
  color: var(--surface);
  background: var(--primary);
}

.primary-button:hover,
.step-action:hover {
  background: var(--primary-strong);
}

.secondary-button {
  color: var(--ink);
  background: var(--surface);
  border: 1px solid var(--line-strong);
}

.secondary-button:hover {
  background: var(--surface-soft);
}

.danger-button {
  color: var(--surface);
  background: var(--danger);
}

.step-action.is-complete {
  color: var(--teal);
  background: var(--teal-soft);
  border: 1px solid var(--teal);
}

.lesson-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
  margin-top: 18px;
  padding-top: 24px;
  border-top: 2px solid var(--ink);
}

.lesson-footer .secondary-button,
.lesson-footer .primary-button {
  max-width: 46%;
}

.app-dialog {
  width: min(620px, calc(100% - 28px));
  max-height: min(82vh, 780px);
  padding: 0;
  color: var(--ink);
  background: var(--surface);
  border: 1px solid var(--line-strong);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

.wide-dialog {
  width: min(760px, calc(100% - 28px));
}

.app-dialog::backdrop {
  background: rgba(10, 20, 17, 0.58);
}

.dialog-header {
  display: flex;
  align-items: start;
  justify-content: space-between;
  gap: 20px;
  padding: 22px 24px 18px;
  border-bottom: 1px solid var(--line);
}

.dialog-header h2 {
  margin: 5px 0 0;
  font-size: 22px;
}

.icon-button {
  display: grid;
  flex: 0 0 44px;
  width: 44px;
  height: 44px;
  place-items: center;
  background: transparent;
  border-radius: 5px;
  font-size: 26px;
}

.icon-button:hover {
  background: var(--surface-soft);
}

.dialog-body {
  max-height: 58vh;
  padding: 20px 24px;
  overflow-y: auto;
}

.dialog-body > p:first-child {
  margin-top: 0;
}

.dialog-body pre {
  padding: 14px;
  color: var(--code-ink);
  background: var(--code-bg);
  border-radius: 5px;
}

.dialog-actions {
  display: flex;
  justify-content: flex-end;
  gap: 10px;
  padding: 16px 24px;
  border-top: 1px solid var(--line);
}

.permission-dialog { max-width: min(560px, calc(100vw - 32px)); }
.permission-scope {
  padding: 12px 14px;
  color: var(--ink);
  background: var(--teal-soft);
  border-left: 3px solid var(--teal);
  font-weight: 700;
}
.permission-actions { flex-wrap: wrap; }

.tutor-panel-mount {
  max-width: 860px;
}

.tutor-panel {
  width: 100%;
  margin: 12px 0 32px;
  color: var(--ink);
  background: color-mix(in srgb, var(--surface) 96%, var(--paper));
  border: 1px solid var(--line-strong);
  border-top: 4px solid var(--primary);
  border-radius: var(--radius);
  box-shadow: 0 10px 26px rgba(23, 35, 31, 0.08);
  scroll-margin-top: 118px;
}

.tutor-panel[hidden] {
  display: none;
}

.tutor-panel-header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 20px;
  padding: 20px 22px 16px;
  border-bottom: 1px solid var(--line);
}

.tutor-panel-header h2 {
  margin: 4px 0 0;
  font-size: 22px;
  line-height: 1.25;
}

.tutor-panel > .tutor-body {
  padding: 18px 22px 22px;
}

.tutor-body {
  display: grid;
  min-width: 0;
  gap: 18px;
}

.tutor-status-row {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 8px 14px;
}

.tutor-connection-status {
  display: flex;
  align-items: center;
  gap: 6px;
}

.tutor-refresh-button {
  display: grid;
  width: 30px;
  height: 30px;
  padding: 0;
  place-items: center;
  color: var(--muted);
  background: transparent;
  border: 0;
  border-radius: 4px;
  cursor: pointer;
  font-size: 18px;
}

.tutor-refresh-button:hover {
  color: var(--ink);
  background: var(--surface-soft);
}

.tutor-refresh-button:disabled {
  cursor: wait;
  opacity: 0.45;
}

.tutor-status {
  display: inline-flex;
  align-items: center;
  min-height: 30px;
  padding: 4px 9px;
  color: var(--muted);
  background: var(--surface-soft);
  border-radius: 4px;
  font-size: 12px;
  font-weight: 700;
}

.tutor-status.is-online {
  color: var(--teal);
  background: var(--teal-soft);
}

.tutor-status.is-offline {
  color: var(--amber);
  background: var(--amber-soft);
}

.tutor-reason {
  margin: -10px 0 0 !important;
}

.tutor-data-access {
  display: grid;
  gap: 12px;
  padding: 14px;
  background: color-mix(in srgb, var(--surface-soft) 72%, var(--surface));
  border: 1px solid var(--line);
  border-radius: 6px;
}

.tutor-access-heading {
  display: flex;
  align-items: start;
  justify-content: space-between;
  gap: 12px;
}

.tutor-access-heading h3 {
  margin: 0;
  font-size: 14px;
}

.tutor-access-heading p,
.tutor-access-note {
  margin: 4px 0 0;
  color: var(--muted);
  font-size: 12px;
  line-height: 1.55;
}

.tutor-access-heading > span {
  flex: 0 0 auto;
  padding: 3px 7px;
  color: var(--teal);
  background: var(--teal-soft);
  border-radius: 4px;
  font-size: 11px;
  font-weight: 800;
}

.tutor-access-list {
  display: grid;
  border-top: 1px solid var(--line);
}

.tutor-access-row {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 12px;
  align-items: center;
  padding: 11px 0;
  border-bottom: 1px solid var(--line);
}

.tutor-access-row > div {
  display: grid;
  gap: 3px;
  min-width: 0;
}

.tutor-access-row strong {
  font-size: 13px;
}

.tutor-access-row span,
.tutor-access-row small {
  color: var(--muted);
  font-size: 11px;
  line-height: 1.45;
}

.tutor-access-row small {
  color: var(--teal);
  font-weight: 700;
}

.tutor-access-button {
  min-height: 36px;
  white-space: nowrap;
}

.tutor-access-revoke {
  width: 36px;
  height: 36px;
  min-height: 36px;
  font-size: 22px;
}

.tutor-suggestion {
  display: grid;
  gap: 10px;
  margin-top: 12px;
  padding-top: 11px;
  border-top: 1px solid var(--line);
  font-size: 12px;
}

.tutor-suggestion > span {
  line-height: 1.6;
}

.tutor-suggestion .secondary-button {
  justify-self: start;
  min-height: 36px;
}

.tutor-settings {
  min-width: 0;
  width: 100%;
  max-width: 100%;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.tutor-settings > summary {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 6px 12px;
  padding: 12px 2px;
  cursor: pointer;
  font-size: 13px;
  font-weight: 800;
}

.tutor-settings-summary {
  color: var(--muted);
  font-size: 11px;
  font-weight: 600;
}

.tutor-settings[open] > summary {
  border-bottom: 1px solid var(--line);
}

.tutor-settings-form {
  display: grid;
  min-width: 0;
  width: 100%;
  max-width: 100%;
  gap: 16px;
  padding: 18px 2px 20px;
}

.tutor-settings-form fieldset {
  min-width: 0;
  margin: 0;
  padding: 0;
  border: 0;
}

.tutor-settings-form legend,
.tutor-field-label {
  margin-bottom: 8px;
  font-size: 12px;
  font-weight: 800;
}

.tutor-field-label small {
  color: var(--muted);
  font-size: 11px;
  font-weight: 500;
}

.tutor-mode-control {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  min-height: 46px;
  padding: 3px;
  background: var(--surface-soft);
  border: 1px solid var(--line);
  border-radius: 6px;
}

.tutor-mode-control label {
  position: relative;
  min-width: 0;
  cursor: pointer;
}

.tutor-mode-control input {
  position: absolute;
  width: 1px;
  height: 1px;
  opacity: 0;
}

.tutor-mode-control span {
  display: grid;
  min-height: 38px;
  padding: 7px 6px;
  place-items: center;
  border: 1px solid transparent;
  border-radius: 4px;
  font-size: 12px;
  font-weight: 700;
  text-align: center;
}

.tutor-mode-control input:checked + span {
  color: var(--teal);
  background: var(--surface);
  border-color: var(--line-strong);
  box-shadow: 0 2px 8px rgba(23, 35, 31, 0.08);
}

.tutor-mode-control input:focus-visible + span {
  outline: 3px solid color-mix(in srgb, var(--focus) 70%, transparent);
  outline-offset: 2px;
}

.tutor-mode-control input:disabled + span {
  cursor: not-allowed;
  opacity: 0.55;
}

.tutor-field {
  display: grid;
  min-width: 0;
  gap: 7px;
}

.tutor-field input,
.tutor-field select {
  min-width: 0;
  width: 100%;
  min-height: 44px;
  padding: 9px 11px;
  color: var(--ink);
  background: var(--surface);
  border: 1px solid var(--line-strong);
  border-radius: 5px;
  font-size: 13px;
}

.tutor-model-field input,
#tutor-api-base,
#tutor-api-path {
  font-family: "SFMono-Regular", Consolas, monospace;
}

.tutor-field input:disabled,
.tutor-field select:disabled {
  color: var(--muted);
  background: var(--surface-soft);
}

.tutor-key-input-row {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 8px;
  align-items: center;
}

.tutor-key-input-row .secondary-button {
  min-height: 44px;
}

.tutor-cloud-settings {
  display: grid;
  min-width: 0;
  width: 100%;
  max-width: 100%;
  gap: 13px;
  padding-top: 15px;
  border-top: 1px solid var(--line);
}

.tutor-cloud-heading {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 8px 16px;
}

.tutor-cloud-heading h3 {
  margin: 0;
  font-size: 14px;
}

.tutor-cloud-heading span {
  color: var(--muted);
  font-size: 11px;
}

.tutor-connection-grid {
  display: grid;
  min-width: 0;
  grid-template-columns: minmax(0, 1.35fr) minmax(0, 1fr);
  gap: 12px;
}

.tutor-wide-field {
  grid-column: 1 / -1;
}

.tutor-request-preview {
  display: grid;
  min-width: 0;
  gap: 3px;
  padding: 9px 11px;
  color: var(--teal);
  background: var(--teal-soft);
  border-left: 4px solid var(--teal);
}

.tutor-request-preview > span {
  font-size: 10px;
  font-weight: 800;
}

.tutor-request-preview output {
  min-width: 0;
  overflow-wrap: anywhere;
  color: var(--ink);
  font-family: "SFMono-Regular", Consolas, monospace;
  font-size: 12px;
  font-weight: 700;
  line-height: 1.5;
}

.tutor-settings-form [hidden] {
  display: none !important;
}

.tutor-settings-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 7px 14px;
  color: var(--muted);
  font-size: 12px;
}

.tutor-setup-help {
  padding: 12px 14px;
  background: var(--amber-soft);
  border-left: 4px solid var(--amber);
}

.tutor-setup-help p {
  margin: 0 0 10px;
  font-size: 12px;
  line-height: 1.65;
}

.tutor-setup-help pre {
  max-width: 100%;
  margin: 0 0 10px;
  overflow-x: auto;
  font-size: 12px;
}

.tutor-setup-help .secondary-button {
  min-height: 38px;
  padding: 0 12px;
  font-size: 12px;
}

.tutor-settings-feedback {
  min-height: 20px;
  margin: -4px 0 0 !important;
}

.tutor-settings-actions {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}

.tutor-settings-actions p {
  max-width: 430px;
  margin: 0;
  color: var(--muted);
  font-size: 11px;
  line-height: 1.55;
}

.tutor-settings-actions .primary-button {
  flex: 0 0 auto;
}

.tutor-settings-actions .primary-button:disabled,
.tutor-form-actions .primary-button:disabled {
  cursor: not-allowed;
  opacity: 0.55;
}

.tutor-messages {
  display: grid;
  gap: 12px;
  min-height: 170px;
  max-height: 310px;
  padding: 16px 0;
  overflow-y: auto;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.tutor-session-bar {
  display: grid;
  gap: 7px;
}

.tutor-session-bar > label {
  color: var(--muted);
  font-size: 12px;
  font-weight: 800;
}

.tutor-session-actions {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto 38px;
  gap: 8px;
}

.tutor-session-actions select {
  min-width: 0;
  min-height: 40px;
  padding: 7px 32px 7px 10px;
  color: var(--ink);
  background: var(--surface);
  border: 1px solid var(--line-strong);
  border-radius: 5px;
}

.tutor-session-actions .secondary-button,
.tutor-session-actions .icon-button {
  min-height: 40px;
}

.tutor-session-actions .icon-button:disabled {
  cursor: not-allowed;
  opacity: 0.35;
}

.tutor-message {
  max-width: 88%;
  padding: 11px 14px;
  line-height: 1.7;
  overflow-wrap: anywhere;
}

.tutor-message.assistant {
  justify-self: start;
  background: var(--surface-soft);
  border-left: 3px solid var(--primary);
}

.tutor-message.user {
  justify-self: end;
  background: color-mix(in srgb, var(--amber-soft) 52%, var(--surface));
  border-right: 3px solid var(--amber);
}

.tutor-message.error {
  color: var(--danger);
  background: var(--danger-soft);
  border-left-color: var(--danger);
}

.tutor-message-plain {
  margin: 0;
}

.tutor-message.rich-text > :first-child,
.tutor-message.rich-text li > :first-child {
  margin-top: 0;
}

.tutor-message.rich-text > :last-child,
.tutor-message.rich-text li > :last-child {
  margin-bottom: 0;
}

.tutor-message.rich-text p,
.tutor-message.rich-text ul,
.tutor-message.rich-text ol,
.tutor-message.rich-text blockquote {
  margin: 0;
}

.tutor-message.rich-text p + p,
.tutor-message.rich-text p + ul,
.tutor-message.rich-text p + ol,
.tutor-message.rich-text ul + p,
.tutor-message.rich-text ol + p,
.tutor-message.rich-text blockquote + p,
.tutor-message.rich-text pre + p,
.tutor-message.rich-text .tutor-math-block + p {
  margin-top: 10px;
}

.tutor-message.rich-text ul,
.tutor-message.rich-text ol {
  padding-left: 20px;
}

.tutor-message.rich-text li + li {
  margin-top: 6px;
}

.tutor-message.rich-text h3,
.tutor-message.rich-text h4,
.tutor-message.rich-text h5 {
  margin: 0;
  font-size: 15px;
  line-height: 1.45;
}

.tutor-message.rich-text h3 + p,
.tutor-message.rich-text h4 + p,
.tutor-message.rich-text h5 + p,
.tutor-message.rich-text h3 + ul,
.tutor-message.rich-text h4 + ul,
.tutor-message.rich-text h5 + ul,
.tutor-message.rich-text h3 + ol,
.tutor-message.rich-text h4 + ol,
.tutor-message.rich-text h5 + ol {
  margin-top: 10px;
}

.tutor-message.rich-text strong {
  font-weight: 800;
}

.tutor-message.rich-text code,
.tutor-math-inline {
  padding: 1px 6px;
  border-radius: 999px;
  font-family: "SFMono-Regular", Consolas, monospace;
  font-size: 0.95em;
}

.tutor-message.rich-text code {
  color: var(--code-ink);
  background: color-mix(in srgb, var(--surface) 70%, white);
}

.tutor-math-inline {
  display: inline-flex;
  max-width: 100%;
  align-items: center;
  color: var(--teal);
  background: color-mix(in srgb, var(--teal-soft) 72%, white);
}

.tutor-code-block,
.tutor-math-block {
  margin: 0;
  padding: 12px 14px;
  border-radius: 8px;
}

.tutor-code-block {
  color: var(--code-ink);
  background: var(--code-bg);
}

.tutor-math-block {
  color: var(--teal);
  background: color-mix(in srgb, var(--teal-soft) 72%, white);
  border-left: 4px solid var(--teal);
  font-family: "SFMono-Regular", Consolas, monospace;
  overflow-x: auto;
}

.tutor-math-inline.is-katex-rendered,
.tutor-math-block.is-katex-rendered {
  color: var(--ink);
  font-family: inherit;
}

.tutor-math-inline.is-katex-rendered {
  padding: 2px 8px;
}

.tutor-math-inline.is-katex-rendered .katex {
  font-size: 1.02em;
}

.tutor-math-block.is-katex-rendered .katex-display {
  margin: 0;
}

.tutor-math-block.is-katex-rendered .katex {
  font-size: 1.04em;
}

.tutor-message.rich-text blockquote {
  padding-left: 12px;
  color: var(--muted);
  border-left: 3px solid color-mix(in srgb, var(--teal) 35%, transparent);
}

.tutor-prompts {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.tutor-prompts .secondary-button {
  min-height: 40px;
  padding: 0 12px;
  font-size: 12px;
}

.tutor-form {
  display: grid;
  gap: 8px;
}

.tutor-form > label {
  font-size: 13px;
  font-weight: 700;
}

.tutor-form textarea {
  width: 100%;
  min-height: 92px;
  padding: 11px 12px;
  color: var(--ink);
  background: var(--surface);
  border: 1px solid var(--line-strong);
  border-radius: 5px;
  resize: vertical;
}

.tutor-form-actions {
  display: flex;
  justify-content: flex-end;
  gap: 8px;
}

.tutor-privacy {
  margin: 0 !important;
}

.environment-ready {
  margin: 14px 0;
  padding: 12px 14px;
  color: var(--teal);
  background: var(--teal-soft);
  border-left: 4px solid var(--teal);
}

#setup-later-button[hidden] {
  display: none;
}

.setup-start-card,
.python-reading-card {
  margin: 18px 0;
  padding: 16px;
  background: var(--surface-soft);
  border-left: 4px solid var(--teal);
}

.setup-start-card h3,
.python-reading-card h3 {
  margin: 0 0 10px;
  font-size: 16px;
}

.setup-start-card p {
  margin: 0 0 10px;
  font-size: 13px;
  line-height: 1.65;
}

.setup-start-card p:last-child {
  margin-bottom: 0;
}

.python-reading-card {
  border-left-color: var(--amber);
}

.python-reading-card dl {
  display: grid;
  gap: 0;
  margin: 0;
}

.python-reading-card dl > div {
  display: grid;
  grid-template-columns: minmax(120px, 0.75fr) minmax(0, 1.6fr);
  gap: 12px;
  padding: 9px 0;
  border-top: 1px solid var(--line);
}

.python-reading-card dt,
.python-reading-card dd {
  margin: 0;
  font-size: 12px;
  line-height: 1.55;
}

.python-reading-card dd {
  color: var(--muted);
}

.glossary-list {
  display: grid;
  margin-top: 18px;
  border-top: 2px solid var(--ink);
}

.glossary-entry {
  display: grid;
  grid-template-columns: minmax(130px, 0.8fr) minmax(240px, 1.7fr) 50px;
  gap: 16px;
  padding: 14px 4px;
  border-bottom: 1px solid var(--line);
}

.glossary-entry strong {
  font-size: 13px;
}

.glossary-entry span {
  color: var(--muted);
  font-size: 13px;
  line-height: 1.55;
}

.glossary-entry small {
  color: var(--primary);
  font-family: "SFMono-Regular", Consolas, monospace;
  text-align: right;
}

.muted-copy {
  color: var(--muted);
  font-size: 13px;
}

.progress-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin: 20px 0;
}

.file-button {
  cursor: pointer;
}

.danger-zone {
  margin-top: 26px;
  padding-top: 16px;
  border-top: 1px solid var(--line);
}

.danger-zone summary {
  color: var(--danger);
  cursor: pointer;
  font-weight: 700;
}

.toast {
  position: fixed;
  z-index: 80;
  right: 20px;
  bottom: 20px;
  max-width: min(360px, calc(100% - 40px));
  padding: 12px 16px;
  color: var(--surface);
  background: var(--ink);
  border-radius: 6px;
  box-shadow: var(--shadow);
  opacity: 0;
  pointer-events: none;
  transform: translateY(12px);
  transition: opacity 160ms ease, transform 160ms ease;
}

.toast.is-visible {
  opacity: 1;
  transform: translateY(0);
}

@media (max-width: 940px) {
  .learning-shell {
    grid-template-columns: 1fr;
    gap: 24px;
    padding-top: 22px;
  }

  .course-rail {
    position: static;
    max-height: none;
    overflow: visible;
  }

  .rail-heading,
  .day-list,
  .rail-note {
    display: none;
  }

  .mobile-day-picker {
    display: grid;
    grid-template-columns: auto minmax(0, 1fr);
    align-items: center;
    gap: 12px;
    padding-bottom: 18px;
    border-bottom: 2px solid var(--ink);
  }

  .mobile-day-picker label {
    font-size: 12px;
    font-weight: 800;
  }

  .mobile-day-picker select {
    min-width: 0;
    min-height: 46px;
    padding: 0 38px 0 12px;
    color: var(--ink);
    background: var(--surface);
    border: 1px solid var(--line-strong);
    border-radius: 5px;
  }
}

@media (max-width: 720px) {
  .topbar {
    grid-template-columns: minmax(0, 1fr) auto;
    grid-template-areas:
      "brand status"
      "actions actions";
    gap: 8px 16px;
    padding: 8px 14px;
  }

  .brand {
    grid-area: brand;
  }

  .top-status {
    grid-area: status;
  }

  .top-actions {
    grid-area: actions;
    justify-content: space-between;
    border-top: 1px solid var(--line);
  }

  .top-actions .icon-text-button {
    flex: 1;
  }

  .overall-progress {
    top: 112px;
  }

  .lesson {
    scroll-margin-top: 126px;
  }

  .lesson-step {
    scroll-margin-top: 126px;
  }

  .lesson-heading-row {
    display: grid;
  }

  .review-toggle {
    width: fit-content;
  }

  .lesson-header h1 {
    font-size: 30px;
  }

  .step-tabs {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .step-tab:nth-child(-n + 3) {
    border-bottom: 1px solid var(--line);
  }

  .mapping-row {
    grid-template-columns: 1fr;
    gap: 6px;
  }

  .tensor-diagram {
    grid-template-columns: 1fr;
  }

  .tensor-arrow {
    grid-template-columns: auto auto;
  }

  .tensor-arrow strong {
    transform: rotate(90deg);
  }

  .model-control,
  .flow-detail,
  .weight-equation {
    grid-template-columns: 1fr;
  }

  .equation-symbol {
    text-align: center;
  }

  .model-total {
    text-align: left;
  }

  .model-nodes,
  .token-stages,
  .pipeline-stages {
    grid-template-columns: 1fr;
  }

  .confidence-group {
    grid-template-columns: 1fr;
  }

  .tutor-message {
    max-width: 96%;
  }

  .glossary-entry {
    grid-template-columns: 1fr;
    gap: 6px;
  }

  .glossary-entry small {
    text-align: left;
  }
}

@media (max-width: 430px) {
  .brand-copy span,
  .save-status {
    display: none;
  }

  .top-actions .icon-text-button {
    padding: 0 4px;
    white-space: nowrap;
  }

  .top-actions .icon-text-button > span:first-child {
    display: none;
  }

  .learning-shell {
    padding-right: 14px;
    padding-left: 14px;
  }

  .lesson-header h1 {
    font-size: 26px;
  }

  .lesson-step h2 {
    font-size: 23px;
  }

  .lesson-step {
    padding-top: 32px;
  }

  .step-time {
    float: none;
    display: block;
    margin-bottom: 8px;
  }

  .lab,
  .math-block,
  .task-block,
  .recap-block {
    padding: 16px;
  }

  .lab-header {
    display: grid;
    gap: 4px;
  }

  .code-toolbar {
    align-items: stretch;
    flex-direction: column;
    padding: 10px;
  }

  .code-description {
    display: grid;
    gap: 6px;
  }

  .code-toolbar code {
    padding: 2px 4px;
    white-space: normal;
    overflow-wrap: anywhere;
  }

  .code-run-status {
    padding: 0 4px;
    border-left: 0;
  }

  .code-actions {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .code-button {
    min-width: 0;
    white-space: nowrap;
  }

  .runner-heading,
  .tutor-expansion {
    align-items: stretch;
    flex-direction: column;
  }

  .runner-controls {
    grid-template-columns: 1fr;
  }

  .runner-controls button,
  .tutor-expansion button {
    width: 100%;
  }

  .step-completion,
  .completion-actions {
    align-items: stretch;
    flex-direction: column;
  }

  .completion-actions,
  .completion-actions .step-action,
  .completion-actions .primary-button {
    width: 100%;
  }

  .python-reading-card dl > div {
    grid-template-columns: 1fr;
    gap: 3px;
  }

  .slow-teaching,
  .tutor-message {
    padding: 14px;
  }

  .tutor-cloud-heading,
  .tutor-connection-grid {
    display: grid;
    grid-template-columns: 1fr;
  }

  .tutor-access-heading {
    display: grid;
  }

  .tutor-access-heading > span {
    width: fit-content;
  }

  .tutor-access-row {
    grid-template-columns: 1fr;
  }

  .tutor-access-button,
  .tutor-suggestion .secondary-button {
    width: 100%;
  }

  .tutor-access-revoke {
    justify-self: start;
  }

  .tutor-wide-field {
    grid-column: auto;
  }

  .tutor-field-label small {
    display: block;
    margin-top: 2px;
  }

  .tutor-prompts,
  .tutor-form-actions,
  .tutor-settings-actions {
    display: grid;
    grid-template-columns: 1fr;
  }

  .tutor-session-actions {
    grid-template-columns: minmax(0, 1fr) 38px;
  }

  .tutor-session-actions .secondary-button {
    grid-column: 1 / -1;
    grid-row: 2;
  }

  .tutor-settings-actions .primary-button {
    width: 100%;
  }

  .tutor-panel {
    margin-top: 8px;
    border-right: 0;
    border-left: 0;
    border-radius: 0;
    box-shadow: none;
  }

  .tutor-panel-header,
  .tutor-panel > .tutor-body {
    padding-right: 14px;
    padding-left: 14px;
  }

  .tutor-panel-header h2 {
    font-size: 20px;
  }

  .range-row {
    grid-template-columns: 30px minmax(70px, 1fr) 40px;
  }

  .attention-tokens {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .lesson-footer .secondary-button,
  .lesson-footer .primary-button {
    min-width: 0;
    padding: 0 10px;
    font-size: 12px;
  }

  .dialog-header,
  .dialog-body,
  .dialog-actions {
    padding-right: 16px;
    padding-left: 16px;
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    scroll-behavior: auto !important;
    transition-duration: 0.01ms !important;
  }
}