:root {
  color-scheme: light;
  --bg: #f7f4ee;
  --surface: #fffdf8;
  --surface-2: #f0ede5;
  --ink: #18262c;
  --muted: #637078;
  --line: #ddd6c7;
  --teal: #00897b;
  --teal-soft: #dff2ee;
  --coral: #e85d5a;
  --coral-soft: #ffe3df;
  --amber: #d99521;
  --amber-soft: #fff0cf;
  --green: #4f7c45;
  --green-soft: #e8f3df;
  --violet: #6556a8;
  --shadow: 0 18px 45px rgba(29, 39, 43, 0.1);
  --radius: 8px;
}

[data-theme="dark"] {
  color-scheme: dark;
  --bg: #141817;
  --surface: #1f2523;
  --surface-2: #2a302e;
  --ink: #f3f1ea;
  --muted: #acb2ad;
  --line: #3a423f;
  --teal: #53c8b8;
  --teal-soft: #193f3a;
  --coral: #ff837d;
  --coral-soft: #4a2424;
  --amber: #f0b94b;
  --amber-soft: #493817;
  --green: #9aca82;
  --green-soft: #273d25;
  --violet: #b0a4f4;
  --shadow: 0 18px 45px rgba(0, 0, 0, 0.24);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-width: 320px;
  background: var(--bg);
  color: var(--ink);
  font-family:
    Inter, "PingFang SC", "Microsoft YaHei", "Noto Sans CJK SC", system-ui,
    -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  font-size: 15px;
  line-height: 1.55;
  letter-spacing: 0;
}

button,
input,
textarea,
select {
  font: inherit;
}

button {
  cursor: pointer;
}

.app-shell {
  min-height: 100vh;
}

.topbar {
  position: sticky;
  top: 0;
  z-index: 10;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 14px 24px;
  background: color-mix(in srgb, var(--surface) 94%, transparent);
  border-bottom: 1px solid var(--line);
  backdrop-filter: blur(14px);
}

.identity {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  color: var(--ink);
  text-decoration: none;
  min-width: 230px;
}

.identity strong,
.identity small {
  display: block;
}

.identity strong {
  font-size: 16px;
}

.identity small {
  color: var(--muted);
  font-size: 12px;
}

.mark {
  display: grid;
  place-items: center;
  width: 42px;
  height: 42px;
  border-radius: var(--radius);
  color: #fffdf8;
  background: #18262c;
  font-weight: 800;
  letter-spacing: 0;
}

.top-actions {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: 10px;
  min-width: 0;
  flex: 1;
}

.search-box {
  display: flex;
  align-items: center;
  gap: 8px;
  width: min(420px, 100%);
  min-width: 190px;
  height: 42px;
  padding: 0 12px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface-2);
  color: var(--muted);
}

.search-box input {
  width: 100%;
  min-width: 0;
  border: 0;
  outline: 0;
  background: transparent;
  color: var(--ink);
}

.icon-button,
.text-button,
.primary-button,
.ghost-button {
  min-height: 40px;
  border-radius: var(--radius);
  border: 1px solid var(--line);
  color: var(--ink);
  background: var(--surface);
}

.icon-button {
  width: 42px;
  padding: 0;
}

.text-button,
.primary-button,
.ghost-button {
  padding: 0 14px;
  white-space: nowrap;
}

.primary-button {
  border-color: #17262c;
  color: #fffdf8;
  background: #17262c;
}

.primary-button:disabled {
  cursor: default;
  opacity: 0.72;
}

.ghost-button {
  color: var(--muted);
}

.workspace {
  display: grid;
  grid-template-columns: minmax(230px, 280px) minmax(0, 1fr) minmax(280px, 350px);
  gap: 18px;
  max-width: 1560px;
  margin: 0 auto;
  padding: 18px 24px 30px;
}

/* 收起左右侧栏，扩大正文阅读区（尤其 iPad） */
.workspace.hide-rail .rail {
  display: none;
}

.workspace.hide-study .study-panel {
  display: none;
}

/* 桌面（>1180）：三栏并排，收起某一栏后其余重排补满 */
@media (min-width: 1181px) {
  .workspace.hide-rail {
    grid-template-columns: minmax(0, 1fr) minmax(280px, 350px);
  }

  .workspace.hide-study {
    grid-template-columns: minmax(230px, 280px) minmax(0, 1fr);
  }

  .workspace.hide-rail.hide-study {
    grid-template-columns: minmax(0, 1fr);
  }
}

/* iPad 横屏（861–1180）：练习区原本在正文下方，收起目录让正文占满整行 */
@media (min-width: 861px) and (max-width: 1180px) {
  .workspace.hide-rail {
    grid-template-columns: minmax(0, 1fr);
  }

  .workspace.hide-rail .study-panel {
    grid-column: auto;
  }
}

.panel-toggle.is-off {
  opacity: 0.45;
}

.rail,
.study-panel {
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.rail {
  position: sticky;
  top: 86px;
  align-self: start;
  max-height: calc(100vh - 104px);
  overflow: auto;
  padding-right: 2px;
}

.study-panel {
  position: sticky;
  top: 86px;
  align-self: start;
  max-height: calc(100vh - 104px);
  overflow: auto;
}

.content-stack {
  display: flex;
  flex-direction: column;
  gap: 16px;
  min-width: 0;
}

.visual-band {
  position: relative;
  min-height: 245px;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: #18262c;
  box-shadow: var(--shadow);
}

.visual-band img {
  width: 100%;
  height: 100%;
  min-height: 245px;
  object-fit: cover;
  display: block;
}

.visual-band::after {
  content: "";
  position: absolute;
  inset: 0;
  background:
    linear-gradient(90deg, rgba(19, 31, 36, 0.88), rgba(19, 31, 36, 0.28) 55%, rgba(19, 31, 36, 0.1)),
    linear-gradient(0deg, rgba(19, 31, 36, 0.22), transparent 48%);
}

.visual-overlay {
  position: absolute;
  z-index: 1;
  inset: auto 34px 28px 34px;
  max-width: 560px;
  color: #fffdf8;
}

.visual-overlay span {
  display: inline-flex;
  align-items: center;
  min-height: 26px;
  padding: 0 9px;
  border: 1px solid rgba(255, 253, 248, 0.35);
  border-radius: 999px;
  background: rgba(255, 253, 248, 0.08);
  font-size: 12px;
}

.visual-overlay h1 {
  margin: 12px 0 8px;
  max-width: 12em;
  font-size: 34px;
  line-height: 1.12;
  letter-spacing: 0;
}

.visual-overlay p {
  max-width: 52ch;
  margin: 0;
  color: rgba(255, 253, 248, 0.82);
}

.progress-panel,
.module-panel,
.tool-panel {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
  box-shadow: 0 8px 24px rgba(29, 39, 43, 0.06);
}

.progress-panel {
  padding: 14px;
}

.progress-copy {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 10px;
}

.progress-copy span,
.section-heading span,
.eyebrow,
.quiz-meta,
.card-meta,
.result-meta {
  color: var(--muted);
  font-size: 12px;
}

.progress-copy strong {
  font-size: 24px;
  line-height: 1;
}

.progress-track {
  height: 10px;
  margin: 12px 0 8px;
  overflow: hidden;
  border-radius: 999px;
  background: var(--surface-2);
}

.progress-track span {
  display: block;
  width: 0;
  height: 100%;
  border-radius: inherit;
  background: linear-gradient(90deg, var(--teal), var(--coral), var(--amber));
  transition: width 220ms ease;
}

#progressHint {
  margin: 0;
  color: var(--muted);
  font-size: 12px;
}

.module-nav {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.nav-section {
  margin: 14px 0 2px;
  padding: 0 4px;
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.04em;
  color: var(--muted, #6b7280);
  text-transform: none;
}

.nav-section:first-child {
  margin-top: 0;
}

.module-button {
  display: grid;
  grid-template-columns: 34px 1fr auto;
  gap: 10px;
  align-items: center;
  width: 100%;
  min-height: 64px;
  padding: 10px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
  color: var(--ink);
  text-align: left;
}

.module-button:hover,
.module-button.is-active {
  border-color: var(--module-color, var(--teal));
  background: color-mix(in srgb, var(--module-color, var(--teal)) 10%, var(--surface));
}

.module-number {
  display: grid;
  place-items: center;
  width: 32px;
  height: 32px;
  border-radius: var(--radius);
  background: var(--module-soft, var(--teal-soft));
  color: var(--module-color, var(--teal));
  font-weight: 800;
}

.module-button strong {
  display: block;
  line-height: 1.2;
}

.module-button small {
  display: block;
  color: var(--muted);
  line-height: 1.3;
  margin-top: 4px;
}

.module-state {
  color: var(--muted);
  font-size: 18px;
}

.module-panel,
.tool-panel {
  padding: 18px;
}

.module-heading,
.section-heading {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 14px;
}

.module-heading h2,
.section-heading h2 {
  margin: 0;
  line-height: 1.25;
  letter-spacing: 0;
}

.module-heading h2 {
  font-size: 24px;
}

.section-heading h2 {
  font-size: 17px;
}

.heading-actions {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
}

.lesson-body {
  margin-top: 18px;
}

.summary-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 10px;
  margin: 0 0 18px;
}

.summary-item {
  min-height: 82px;
  padding: 12px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface-2);
}

.summary-item strong {
  display: block;
  margin-bottom: 4px;
}

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

.content-block {
  display: grid;
  grid-template-columns: minmax(0, 1.2fr) minmax(220px, 0.8fr);
  gap: 18px;
  align-items: start;
}

.content-block h3,
.misconceptions h3 {
  margin: 0 0 10px;
  font-size: 17px;
}

.idea-list,
.outcome-list,
.misconceptions ul {
  display: grid;
  gap: 9px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.idea-list li,
.outcome-list li,
.misconceptions li {
  position: relative;
  padding-left: 18px;
}

.idea-list li::before,
.outcome-list li::before,
.misconceptions li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.68em;
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--accent, var(--teal));
}

.outcome-box {
  padding: 14px;
  border-left: 4px solid var(--accent, var(--teal));
  border-radius: var(--radius);
  background: var(--surface-2);
}

.misconceptions {
  margin-top: 18px;
  padding-top: 16px;
  border-top: 1px solid var(--line);
}

.step-lesson {
  margin: 18px 0;
  padding: 16px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface-2);
}

.step-lesson-head {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(160px, 220px);
  gap: 14px;
  align-items: end;
  margin-bottom: 14px;
}

.step-lesson-head h3 {
  margin: 5px 0 0;
  font-size: 19px;
  line-height: 1.3;
}

.step-progress-track {
  height: 9px;
  overflow: hidden;
  border-radius: 999px;
  background: color-mix(in srgb, var(--surface) 75%, var(--line));
}

.step-progress-track span {
  display: block;
  height: 100%;
  border-radius: inherit;
  background: var(--accent, var(--teal));
}

.step-workspace {
  display: grid;
  grid-template-columns: minmax(180px, 230px) minmax(0, 1fr);
  gap: 16px;
  align-items: start;
}

.step-list {
  display: grid;
  gap: 8px;
}

.step-button {
  display: grid;
  grid-template-columns: 30px 1fr;
  gap: 9px;
  align-items: center;
  min-height: 46px;
  padding: 8px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
  color: var(--ink);
  text-align: left;
}

.step-button span {
  display: grid;
  place-items: center;
  width: 28px;
  height: 28px;
  border-radius: 50%;
  background: var(--surface-2);
  color: var(--muted);
  font-weight: 800;
}

.step-button strong {
  overflow-wrap: anywhere;
  font-size: 13px;
  line-height: 1.25;
}

.step-button.is-active {
  border-color: var(--accent, var(--teal));
  background: color-mix(in srgb, var(--accent, var(--teal)) 12%, var(--surface));
}

.step-button.is-done span {
  color: #fffdf8;
  background: var(--green);
}

.step-detail {
  min-height: 290px;
  padding: 16px 0 0;
  border-top: 1px solid var(--line);
}

.step-pill {
  display: inline-flex;
  align-items: center;
  min-height: 28px;
  padding: 0 10px;
  border-radius: 999px;
  color: var(--accent, var(--teal));
  background: color-mix(in srgb, var(--accent, var(--teal)) 12%, var(--surface));
  font-size: 13px;
  font-weight: 700;
}

.step-detail p {
  margin: 14px 0;
  max-width: 72ch;
}

.step-note {
  display: grid;
  gap: 5px;
  margin-top: 10px;
  padding: 12px;
  border-left: 4px solid var(--accent, var(--teal));
  border-radius: var(--radius);
  background: var(--surface);
}

.step-note strong {
  font-size: 13px;
}

.step-note span {
  color: var(--muted);
}

.lecture-guide {
  margin: 18px 0;
  padding: 16px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface-2);
}

.lecture-guide-head {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 10px;
}

.lecture-guide-head h3 {
  margin: 4px 0 0;
  font-size: 18px;
  line-height: 1.3;
}

.lecture-guide-head > span {
  flex: 0 0 auto;
  color: var(--muted);
  font-size: 12px;
}

.lecture-guide p {
  max-width: 86ch;
  margin: 0 0 14px;
}

.guide-grid,
.deep-note-grid {
  display: grid;
  gap: 12px;
}

.guide-grid {
  grid-template-columns: minmax(220px, 0.75fr) minmax(0, 1.25fr);
}

.deep-note-grid {
  grid-template-columns: repeat(2, minmax(0, 1fr));
  margin-top: 14px;
}

.deep-note {
  padding: 13px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
}

.deep-note h4 {
  margin: 0 0 8px;
  font-size: 14px;
  line-height: 1.25;
}

.deep-note ul {
  display: grid;
  gap: 7px;
  margin: 0;
  padding-left: 18px;
}

.deep-note li {
  color: var(--muted);
}

.step-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 14px;
}

.quiz-question {
  margin-top: 12px;
}

.quiz-question h3 {
  margin: 0 0 10px;
  font-size: 16px;
  line-height: 1.35;
}

.choice-list {
  display: grid;
  gap: 8px;
  margin: 12px 0;
}

.choice-button {
  width: 100%;
  min-height: 42px;
  padding: 10px 12px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface-2);
  color: var(--ink);
  text-align: left;
}

.choice-button:hover {
  border-color: var(--teal);
}

.choice-button.is-correct {
  border-color: var(--green);
  background: var(--green-soft);
}

.choice-button.is-wrong {
  border-color: var(--coral);
  background: var(--coral-soft);
}

.feedback-box {
  min-height: 44px;
  padding: 10px 12px;
  border-radius: var(--radius);
  background: var(--surface-2);
  color: var(--muted);
}

.feedback-box.is-correct {
  background: var(--green-soft);
  color: var(--ink);
}

.feedback-box.is-wrong {
  background: var(--coral-soft);
  color: var(--ink);
}

.quiz-actions,
.card-actions,
.lab-actions {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  margin-top: 12px;
}

.flashcard {
  min-height: 180px;
  margin-top: 14px;
  padding: 18px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface-2);
}

.flashcard button {
  width: 100%;
  min-height: 136px;
  padding: 0;
  border: 0;
  color: var(--ink);
  background: transparent;
  text-align: left;
}

.flashcard strong {
  display: block;
  margin-bottom: 10px;
  font-size: 20px;
  line-height: 1.25;
}

.flashcard p {
  margin: 0;
  color: var(--muted);
}

textarea {
  width: 100%;
  margin-top: 14px;
  resize: vertical;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 12px;
  background: var(--surface-2);
  color: var(--ink);
  outline: none;
}

textarea:focus,
input:focus,
select:focus {
  border-color: var(--teal);
  box-shadow: 0 0 0 3px color-mix(in srgb, var(--teal) 22%, transparent);
}

.lab-host {
  margin-top: 16px;
}

.lab-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(220px, 300px);
  gap: 16px;
  align-items: start;
}

.control-group {
  display: grid;
  gap: 12px;
}

.range-row,
.select-row {
  display: grid;
  grid-template-columns: 88px 1fr 64px;
  gap: 10px;
  align-items: center;
}

.range-row label,
.select-row label {
  color: var(--muted);
  font-size: 13px;
}

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

.metric-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 10px;
}

.metric {
  min-height: 74px;
  padding: 12px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface-2);
}

.metric span {
  display: block;
  color: var(--muted);
  font-size: 12px;
}

.metric strong {
  display: block;
  margin-top: 4px;
  font-size: 22px;
  line-height: 1;
}

.formula {
  display: block;
  padding: 12px;
  border-radius: var(--radius);
  background: #17262c;
  color: #fffdf8;
  font-family: "SFMono-Regular", Consolas, "Liberation Mono", monospace;
  white-space: pre-wrap;
}

.token-input,
.rag-input {
  width: 100%;
  min-height: 44px;
  padding: 10px 12px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface-2);
  color: var(--ink);
}

.token-cloud,
.chunk-list,
.heatmap,
.scenario-list {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 12px;
}

.token-chip,
.chunk-item,
.scenario-button {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface-2);
  color: var(--ink);
}

.token-chip {
  padding: 6px 9px;
  min-height: 32px;
}

.chunk-item {
  width: 100%;
  padding: 12px;
}

.chunk-item strong {
  display: block;
}

.chunk-item small {
  display: block;
  margin-top: 4px;
  color: var(--muted);
}

.scenario-button {
  padding: 10px 12px;
}

.scenario-button.is-active {
  border-color: var(--teal);
  background: var(--teal-soft);
}

.attention-table {
  width: 100%;
  border-collapse: collapse;
  margin-top: 12px;
  overflow: hidden;
  border-radius: var(--radius);
}

.attention-table th,
.attention-table td {
  min-width: 54px;
  height: 42px;
  border: 1px solid var(--line);
  text-align: center;
}

.attention-table th {
  color: var(--muted);
  background: var(--surface-2);
  font-weight: 600;
}

.attention-cell {
  color: #17262c;
  font-weight: 700;
}

.plot {
  width: 100%;
  min-height: 230px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface-2);
}

.plot svg {
  display: block;
  width: 100%;
  height: 230px;
}

.lab-table {
  min-width: 0;
}

.compact-table th,
.compact-table td {
  height: 36px;
  min-width: 72px;
  padding: 6px 8px;
}

.toggle-row {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  min-height: 40px;
  color: var(--muted);
}

.bar-viz {
  display: flex;
  align-items: end;
  gap: 10px;
  height: 180px;
  margin-top: 14px;
  padding: 14px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface-2);
}

.bar-viz span {
  flex: 1;
  min-width: 22px;
  border-radius: 4px 4px 0 0;
  background: var(--teal);
}

.bar-viz span.is-hot {
  background: var(--coral);
}

.tree-viz {
  display: grid;
  gap: 10px;
  padding: 12px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface-2);
}

.tree-row {
  display: flex;
  align-items: center;
  gap: 8px;
  min-height: 34px;
}

.tree-row span {
  width: 34px;
  color: var(--muted);
  font-size: 12px;
}

.tree-row b {
  display: grid;
  place-items: center;
  flex: 1;
  min-width: 26px;
  min-height: 28px;
  border-radius: var(--radius);
  color: #fffdf8;
  background: var(--accent, var(--teal));
  font-size: 12px;
}

.summary-item a {
  color: var(--accent, var(--teal));
  font-weight: 700;
  text-decoration: none;
}

.summary-item a:hover {
  text-decoration: underline;
}

.search-results {
  position: fixed;
  top: 72px;
  right: 24px;
  z-index: 20;
  width: min(560px, calc(100vw - 48px));
  max-height: calc(100vh - 100px);
  overflow: auto;
  padding: 12px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
  box-shadow: var(--shadow);
}

.result-button {
  display: block;
  width: 100%;
  padding: 12px;
  border: 0;
  border-radius: var(--radius);
  color: var(--ink);
  background: transparent;
  text-align: left;
}

.result-button:hover {
  background: var(--surface-2);
}

.result-button strong,
.result-button small {
  display: block;
}

.result-button small {
  color: var(--muted);
  margin-top: 4px;
}

.toast {
  position: fixed;
  left: 50%;
  bottom: 24px;
  z-index: 30;
  transform: translate(-50%, 120%);
  max-width: min(520px, calc(100vw - 32px));
  padding: 12px 14px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  color: var(--ink);
  background: var(--surface);
  box-shadow: var(--shadow);
  opacity: 0;
  transition: transform 180ms ease, opacity 180ms ease;
}

.toast.is-visible {
  transform: translate(-50%, 0);
  opacity: 1;
}

.empty-state {
  padding: 12px;
  border-radius: var(--radius);
  background: var(--surface-2);
  color: var(--muted);
}

@media (max-width: 1180px) {
  .workspace {
    grid-template-columns: minmax(210px, 260px) minmax(0, 1fr);
  }

  .study-panel {
    grid-column: 2;
    position: static;
    max-height: none;
  }
}

@media (max-width: 860px) {
  .topbar {
    position: static;
    align-items: flex-start;
    flex-direction: column;
    padding: 14px 16px;
  }

  .top-actions {
    width: 100%;
  }

  .workspace {
    grid-template-columns: 1fr;
    padding: 14px 16px 26px;
  }

  .rail,
  .study-panel {
    position: static;
    max-height: none;
    grid-column: auto;
  }

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

  .summary-grid,
  .content-block,
  .step-lesson-head,
  .step-workspace,
  .guide-grid,
  .deep-note-grid,
  .lab-grid {
    grid-template-columns: 1fr;
  }

  .step-list {
    display: flex;
    overflow-x: auto;
    padding-bottom: 4px;
  }

  .step-button {
    min-width: 150px;
  }

  .step-detail {
    min-height: 0;
  }

  .visual-overlay {
    inset: auto 18px 20px 18px;
  }

  .visual-overlay h1 {
    font-size: 28px;
  }
}

@media (max-width: 560px) {
  body {
    font-size: 14px;
  }

  .top-actions {
    flex-wrap: wrap;
  }

  .search-box {
    flex-basis: 100%;
  }

  .module-nav {
    grid-template-columns: 1fr;
  }

  .module-button {
    grid-template-columns: 32px 1fr auto;
  }

  .module-heading,
  .section-heading {
    align-items: stretch;
    flex-direction: column;
  }

  .heading-actions,
  .heading-actions button {
    width: 100%;
  }

  .step-actions button {
    flex: 1 1 120px;
  }

  .range-row,
  .select-row {
    grid-template-columns: 74px 1fr 54px;
  }

  .metric-grid {
    grid-template-columns: 1fr;
  }

  .attention-table {
    font-size: 12px;
  }

  .attention-table th,
  .attention-table td {
    min-width: 42px;
  }
}