* {
  box-sizing: border-box;
  letter-spacing: 0;
}

[hidden] {
  display: none !important;
}

html {
  min-width: 320px;
  background: var(--cp-bg);
  scroll-behavior: smooth;
}

body {
  min-height: 100vh;
  margin: 0;
  background: var(--cp-bg);
  color: var(--cp-text);
  font-family: "Segoe UI", Aptos, Calibri, -apple-system, BlinkMacSystemFont, sans-serif;
  font-size: 16px;
  line-height: 1.5;
}

button,
input,
select {
  font: inherit;
}

button,
select,
input[type="checkbox"],
input[type="radio"] {
  cursor: pointer;
}

button:focus-visible,
input:focus-visible,
select:focus-visible,
summary:focus-visible,
a:focus-visible {
  outline: 3px solid var(--cp-highlight);
  outline-offset: 2px;
}

button:disabled {
  cursor: not-allowed;
  opacity: 0.5;
}

.skip-link {
  position: fixed;
  z-index: 100;
  top: 8px;
  left: 8px;
  padding: 8px 12px;
  border-radius: 10px;
  background: var(--cp-accent);
  color: var(--cp-accent-fg);
  transform: translateY(-150%);
}

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

.app-shell {
  min-height: 100vh;
  display: grid;
  grid-template-columns: 176px minmax(0, 1fr);
  grid-template-rows: 68px minmax(0, 1fr);
}

.topbar {
  position: sticky;
  z-index: 20;
  top: 0;
  grid-column: 1 / -1;
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-width: 0;
  height: 68px;
  padding: 0 20px;
  border-bottom: 1px solid var(--cp-border);
  background: var(--cp-bg-elevated);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  min-width: 0;
  padding: 0;
  border: 0;
  background: transparent;
  color: var(--cp-text);
  text-align: left;
}

.brand-mark {
  display: grid;
  width: 40px;
  height: 40px;
  place-items: center;
  border: 1px solid var(--cp-border-strong);
  border-radius: 10px;
  color: var(--cp-accent);
  font-family: Consolas, "Courier New", Courier, monospace;
  font-size: 13px;
  font-weight: 800;
}

.brand-copy {
  display: grid;
  min-width: 0;
}

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

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

.topbar-status {
  display: flex;
  align-items: center;
  gap: 12px;
  min-width: 0;
}

.global-timer {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  min-width: 126px;
  font-family: Consolas, "Courier New", Courier, monospace;
  font-size: 13px;
  font-variant-numeric: tabular-nums;
}

.timer-divider,
.data-state {
  color: var(--cp-text-muted);
}

.data-state {
  max-width: 180px;
  overflow: hidden;
  font-size: 12px;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.sidebar {
  position: sticky;
  top: 68px;
  align-self: start;
  height: calc(100vh - 68px);
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  padding: 20px 12px;
  border-right: 1px solid var(--cp-border);
  background: var(--cp-bg-elevated);
}

.primary-nav {
  display: grid;
  gap: 6px;
}

.nav-button,
.text-button {
  width: 100%;
  min-height: 44px;
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 9px 12px;
  border: 1px solid transparent;
  border-radius: 10px;
  background: transparent;
  color: var(--cp-text-muted);
  text-align: left;
}

.nav-button:hover,
.text-button:hover {
  border-color: var(--cp-border);
  background: var(--cp-surface-soft);
  color: var(--cp-text);
}

.nav-button.is-active {
  border-color: var(--cp-border-strong);
  background: var(--cp-surface);
  color: var(--cp-text);
  font-weight: 700;
}

.nav-button.is-active span:first-child {
  color: var(--cp-accent);
}

.sidebar-footer {
  padding-top: 12px;
  border-top: 1px solid var(--cp-border);
}

.danger-text {
  color: var(--cp-danger);
}

main {
  min-width: 0;
  width: 100%;
  max-width: 1440px;
  margin: 0 auto;
  padding: 40px clamp(24px, 4vw, 68px) 72px;
}

.view {
  min-width: 0;
  animation: view-enter 180ms ease-out both;
}

@keyframes view-enter {
  from { opacity: 0; transform: translateY(6px); }
  to { opacity: 1; transform: translateY(0); }
}

.view-heading,
.section-heading {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: 24px;
}

.view-heading {
  margin-bottom: 28px;
}

.view-heading h1,
.section-heading h2,
.vehicle-copy h2,
.empty-state h1,
.empty-state h2 {
  margin: 0;
  line-height: 1.2;
}

.view-heading h1 {
  font-size: 32px;
}

.view-heading p:not(.eyebrow) {
  margin: 8px 0 0;
  color: var(--cp-text-muted);
}

.eyebrow,
.section-index {
  margin: 0 0 6px;
  color: var(--cp-accent);
  font-family: Consolas, "Courier New", Courier, monospace;
  font-size: 11px;
  font-weight: 800;
  text-transform: uppercase;
}

.icon-button,
.primary-button,
.secondary-button,
.danger-button {
  min-height: 42px;
  border-radius: 10px;
  font-weight: 700;
  transition: transform 120ms ease, border-color 120ms ease, background 120ms ease;
}

.icon-button:active,
.primary-button:active,
.secondary-button:active,
.danger-button:active {
  transform: translateY(1px);
}

.icon-button {
  width: 42px;
  min-width: 42px;
  padding: 0;
  border: 1px solid var(--cp-border);
  background: var(--cp-surface);
  color: var(--cp-text);
}

.icon-button:hover {
  border-color: var(--cp-border-strong);
  background: var(--cp-surface-soft);
}

.primary-button,
.secondary-button,
.danger-button {
  padding: 9px 16px;
}

.primary-button {
  border: 1px solid var(--cp-accent);
  background: var(--cp-accent);
  color: var(--cp-accent-fg);
}

.primary-button:hover {
  border-color: var(--cp-accent-hover);
  background: var(--cp-accent-hover);
}

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

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

.danger-button {
  border: 1px solid var(--cp-danger);
  background: var(--cp-danger);
  color: var(--cp-accent-fg);
}

.vehicle-band {
  min-height: 230px;
  display: grid;
  grid-template-columns: minmax(300px, 0.9fr) minmax(360px, 1.1fr);
  overflow: hidden;
  margin-bottom: 20px;
  border: 1px solid var(--cp-border-strong);
  border-radius: 16px;
  background: var(--cp-surface);
}

.vehicle-copy {
  align-content: center;
  padding: 32px;
}

.vehicle-copy h2 {
  font-size: 28px;
}

.vehicle-facts {
  margin: 24px 0 0;
  display: grid;
  gap: 10px;
}

.vehicle-facts div {
  display: grid;
  grid-template-columns: 84px 1fr;
  gap: 12px;
  padding-top: 10px;
  border-top: 1px solid var(--cp-border);
}

.vehicle-facts dt {
  color: var(--cp-text-muted);
  font-size: 13px;
}

.vehicle-facts dd {
  margin: 0;
  font-weight: 700;
}

.vehicle-visual {
  position: relative;
  min-height: 230px;
  margin: 0;
  overflow: hidden;
  background: var(--cp-surface-soft);
}

.vehicle-visual img {
  width: 100%;
  height: 100%;
  min-height: 230px;
  display: block;
  object-fit: cover;
  object-position: center 18%;
  filter: grayscale(1) contrast(1.05);
}

.vehicle-visual figcaption {
  position: absolute;
  right: 12px;
  bottom: 10px;
  max-width: calc(100% - 24px);
  padding: 5px 8px;
  border-radius: 8px;
  background: var(--cp-panel-strong);
  color: var(--cp-text-muted);
  font-size: 11px;
}

.stat-strip {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  margin-bottom: 36px;
  border: 1px solid var(--cp-border);
  border-radius: 16px;
  background: var(--cp-surface);
}

.stat-strip article {
  min-width: 0;
  display: grid;
  gap: 4px;
  padding: 20px 22px;
  border-right: 1px solid var(--cp-border);
}

.stat-strip article:last-child {
  border-right: 0;
}

.stat-strip span,
.stat-strip small,
.history-summary span {
  color: var(--cp-text-muted);
  font-size: 12px;
}

.stat-strip strong {
  font-family: Consolas, "Courier New", Courier, monospace;
  font-size: 25px;
  font-variant-numeric: tabular-nums;
}

.workspace-section,
.history-chart-section,
.history-table-section {
  margin-top: 36px;
}

.section-heading {
  margin-bottom: 16px;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--cp-border-strong);
}

.section-heading h2 {
  font-size: 21px;
}

.section-note {
  color: var(--cp-text-muted);
  font-size: 13px;
}

.setup-section {
  padding: 24px;
  border: 1px solid var(--cp-border);
  border-left: 4px solid var(--cp-accent);
  border-radius: 16px;
  background: var(--cp-surface);
}

.session-form {
  display: grid;
  grid-template-columns: minmax(220px, 1.4fr) minmax(190px, 1fr) minmax(130px, 0.7fr) auto auto auto;
  align-items: end;
  gap: 16px;
}

.field-control,
.compact-field {
  display: grid;
  gap: 7px;
  color: var(--cp-text-muted);
  font-size: 12px;
  font-weight: 700;
}

.field-control select,
.field-control input[type="number"],
.compact-field select {
  width: 100%;
  min-height: 42px;
  padding: 8px 11px;
  border: 1px solid var(--cp-border);
  border-radius: 10px;
  background: var(--cp-surface);
  color: var(--cp-text);
}

.segmented-field {
  min-width: 0;
  margin: 0;
  padding: 0;
  border: 0;
}

.segmented-field legend {
  margin-bottom: 7px;
}

.segmented-control {
  height: 42px;
  display: grid;
  grid-template-columns: 1fr 1fr;
  padding: 3px;
  border: 1px solid var(--cp-border);
  border-radius: 10px;
  background: var(--cp-surface-soft);
}

.segmented-control label {
  position: relative;
  display: grid;
  place-items: center;
  cursor: pointer;
}

.segmented-control input {
  position: absolute;
  opacity: 0;
}

.segmented-control span {
  width: 100%;
  height: 100%;
  display: grid;
  place-items: center;
  border-radius: 7px;
  color: var(--cp-text-muted);
}

.segmented-control input:checked + span {
  background: var(--cp-surface);
  color: var(--cp-text);
  font-weight: 700;
}

.number-control {
  display: grid;
  grid-template-columns: 1fr auto;
  align-items: center;
  gap: 8px;
}

.number-control span {
  white-space: nowrap;
}

.toggle-control {
  min-height: 42px;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  color: var(--cp-text-muted);
  font-size: 13px;
  white-space: nowrap;
}

.toggle-control input {
  position: absolute;
  opacity: 0;
}

.toggle-track {
  position: relative;
  width: 34px;
  height: 20px;
  border: 1px solid var(--cp-border-strong);
  border-radius: 10px;
  background: var(--cp-surface-soft);
}

.toggle-track::after {
  position: absolute;
  top: 3px;
  left: 3px;
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--cp-border-strong);
  content: "";
  transition: transform 140ms ease, background 140ms ease;
}

.toggle-control input:checked + .toggle-track {
  border-color: var(--cp-accent);
  background: var(--cp-accent-soft);
}

.toggle-control input:checked + .toggle-track::after {
  background: var(--cp-accent);
  transform: translateX(14px);
}

.start-button {
  min-width: 110px;
}

.chapter-list {
  border-top: 1px solid var(--cp-border);
}

.chapter-row {
  display: grid;
  grid-template-columns: 52px minmax(180px, 1fr) minmax(180px, 0.8fr) 42px;
  align-items: center;
  gap: 16px;
  padding: 15px 8px;
  border-bottom: 1px solid var(--cp-border);
}

.chapter-row:hover {
  background: var(--cp-accent-soft);
}

.chapter-number {
  color: var(--cp-accent);
  font-family: Consolas, "Courier New", Courier, monospace;
  font-size: 18px;
  font-weight: 800;
}

.chapter-copy {
  min-width: 0;
  display: grid;
}

.chapter-copy strong {
  overflow-wrap: anywhere;
}

.chapter-copy span {
  margin-top: 3px;
  color: var(--cp-text-muted);
  font-size: 12px;
}

.chapter-progress {
  display: grid;
  grid-template-columns: 1fr 46px;
  align-items: center;
  gap: 10px;
  font-family: Consolas, "Courier New", Courier, monospace;
  font-size: 12px;
}

.chapter-progress-track,
.study-progress-track {
  overflow: hidden;
  border-radius: 8px;
  background: var(--cp-border);
}

.chapter-progress-track {
  height: 5px;
}

.chapter-progress-bar,
#session-progress-bar {
  height: 100%;
  display: block;
  background: var(--cp-accent);
}

.study-toolbar {
  position: sticky;
  z-index: 10;
  top: 84px;
  display: grid;
  grid-template-columns: auto minmax(150px, auto) minmax(120px, 1fr) auto auto;
  align-items: center;
  gap: 14px;
  padding: 12px;
  border: 1px solid var(--cp-border);
  border-radius: 16px;
  background: var(--cp-panel-strong);
  box-shadow: 0 0 0 1px var(--cp-sheen);
}

.study-progress-copy {
  display: grid;
}

.study-progress-copy span {
  color: var(--cp-text-muted);
  font-size: 12px;
}

.study-progress-track {
  height: 6px;
}

.study-clock {
  display: flex;
  align-items: center;
  gap: 18px;
}

.study-clock span {
  display: grid;
}

.study-clock small {
  color: var(--cp-text-muted);
  font-size: 10px;
  text-transform: uppercase;
}

.study-clock strong {
  font-family: Consolas, "Courier New", Courier, monospace;
  font-size: 14px;
  font-variant-numeric: tabular-nums;
}

.study-actions,
.heading-actions,
.dialog-actions,
.mistake-actions {
  display: flex;
  align-items: center;
  gap: 8px;
}

.bookmark-button[aria-pressed="true"] {
  border-color: var(--cp-warning);
  color: var(--cp-warning);
}

.question-workspace {
  max-width: 980px;
  margin: 42px auto 0;
  padding-bottom: 60px;
}

.question-workspace.is-paused::before {
  display: block;
  margin-bottom: 16px;
  padding: 9px 12px;
  border-left: 4px solid var(--cp-warning);
  background: var(--cp-surface-soft);
  color: var(--cp-text-muted);
  content: "计时已暂停";
}

.question-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 7px;
  margin-bottom: 16px;
}

.meta-badge {
  padding: 4px 8px;
  border: 1px solid var(--cp-border);
  border-radius: 8px;
  background: var(--cp-surface-soft);
  color: var(--cp-text-muted);
  font-size: 11px;
  font-weight: 700;
}

.knowledge-tag {
  border-color: var(--cp-accent);
  background: var(--cp-accent-soft);
  color: var(--cp-accent);
}

#question-text {
  max-width: 920px;
  margin: 0 0 28px;
  font-size: 25px;
  line-height: 1.42;
  overflow-wrap: anywhere;
}

.option-list {
  display: grid;
  gap: 11px;
}

.option-button {
  width: 100%;
  min-height: 58px;
  display: grid;
  grid-template-columns: 38px minmax(0, 1fr);
  align-items: center;
  gap: 12px;
  padding: 11px 14px;
  border: 1px solid var(--cp-border);
  border-radius: 10px;
  background: var(--cp-surface);
  color: var(--cp-text);
  text-align: left;
}

.option-button:hover:not(:disabled) {
  border-color: var(--cp-border-strong);
  background: var(--cp-accent-soft);
}

.option-button.is-selected {
  border-color: var(--cp-accent);
  box-shadow: inset 4px 0 0 var(--cp-accent);
}

.option-button.is-correct {
  border-color: var(--cp-success);
  box-shadow: inset 4px 0 0 var(--cp-success);
  opacity: 1;
}

.option-button.is-wrong {
  border-color: var(--cp-danger);
  box-shadow: inset 4px 0 0 var(--cp-danger);
  opacity: 1;
}

.option-letter {
  width: 34px;
  height: 34px;
  display: grid;
  place-items: center;
  border: 1px solid var(--cp-border-strong);
  border-radius: 8px;
  font-family: Consolas, "Courier New", Courier, monospace;
  font-weight: 800;
}

.option-text {
  overflow-wrap: anywhere;
}

.multiple-submit,
.question-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  margin-top: 18px;
}

.multiple-submit span,
.question-footer span {
  color: var(--cp-text-muted);
  font-size: 13px;
}

.feedback-panel {
  margin-top: 24px;
  padding: 20px;
  border: 1px solid var(--cp-border);
  border-left-width: 5px;
  border-radius: 10px;
  background: var(--cp-surface);
}

.feedback-panel.is-correct {
  border-left-color: var(--cp-success);
}

.feedback-panel.is-wrong {
  border-left-color: var(--cp-danger);
}

.feedback-heading {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 14px;
  font-size: 18px;
  font-weight: 800;
}

.feedback-symbol {
  width: 30px;
  height: 30px;
  display: grid;
  place-items: center;
  border: 1px solid currentColor;
  border-radius: 50%;
}

.feedback-panel.is-correct .feedback-symbol {
  color: var(--cp-success);
}

.feedback-panel.is-wrong .feedback-symbol {
  color: var(--cp-danger);
}

.correct-answer-line,
.feedback-explanation,
.memory-rule {
  margin: 10px 0;
}

.memory-rule {
  padding: 10px 12px;
  border-left: 4px solid var(--cp-accent);
  background: var(--cp-accent-soft);
}

.feedback-details {
  margin-top: 12px;
  border-top: 1px solid var(--cp-border);
  padding-top: 12px;
}

.feedback-details summary {
  color: var(--cp-link);
  cursor: pointer;
  font-weight: 700;
}

.analysis-title {
  margin: 20px 0 10px;
  font-size: 15px;
}

.analysis-list,
.source-list {
  margin: 0;
  padding: 0;
  list-style: none;
}

.analysis-list li {
  display: grid;
  gap: 3px;
  padding: 10px 0;
  border-bottom: 1px solid var(--cp-border);
}

.analysis-list li span,
.source-list,
.evidence-block {
  color: var(--cp-text-muted);
  font-size: 13px;
}

.analysis-list li.is-correct strong {
  color: var(--cp-success);
}

.evidence-block {
  margin-top: 16px;
}

.source-list {
  margin-top: 6px;
}

.source-list li {
  margin: 4px 0;
  overflow-wrap: anywhere;
}

.question-footer {
  padding-top: 18px;
  border-top: 1px solid var(--cp-border);
}

.empty-state {
  min-height: 440px;
  display: grid;
  place-items: center;
  align-content: center;
  padding: 48px 24px;
  text-align: center;
}

.empty-state p {
  margin: 8px 0 20px;
  color: var(--cp-text-muted);
}

.empty-symbol {
  margin-bottom: 12px;
  color: var(--cp-accent);
  font-size: 34px;
}

.compact-empty {
  min-height: 260px;
  border: 1px dashed var(--cp-border-strong);
  border-radius: 16px;
}

.list-toolbar {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: 16px;
  margin-bottom: 14px;
}

.compact-field {
  grid-template-columns: auto minmax(180px, 260px);
  align-items: center;
}

.mistake-list {
  border-top: 1px solid var(--cp-border);
}

.mistake-row {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  align-items: center;
  gap: 20px;
  padding: 18px 6px;
  border-bottom: 1px solid var(--cp-border);
}

.mistake-copy p {
  margin: 8px 0 0;
  font-size: 16px;
  overflow-wrap: anywhere;
}

.mistake-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  color: var(--cp-text-muted);
  font-size: 12px;
}

.mistake-meta strong {
  color: var(--cp-accent);
  font-family: Consolas, "Courier New", Courier, monospace;
}

.status-wrong {
  color: var(--cp-danger);
}

.history-summary {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  border: 1px solid var(--cp-border);
  border-radius: 16px;
  background: var(--cp-surface);
}

.history-summary article {
  display: grid;
  gap: 8px;
  padding: 22px;
  border-right: 1px solid var(--cp-border);
}

.history-summary article:last-child {
  border-right: 0;
}

.history-summary strong {
  font-family: Consolas, "Courier New", Courier, monospace;
  font-size: 28px;
}

.chart-frame {
  position: relative;
  min-height: 300px;
  display: grid;
  place-items: center;
  overflow: hidden;
  border: 1px solid var(--cp-border);
  border-radius: 16px;
  background: var(--cp-surface);
}

#history-chart {
  width: 100%;
  max-height: 330px;
  padding: 12px;
  color: var(--cp-accent);
}

.chart-grid-line {
  stroke: var(--cp-border);
  stroke-width: 1;
}

.chart-axis-label {
  fill: var(--cp-text-muted);
  font-family: Consolas, "Courier New", Courier, monospace;
  font-size: 11px;
}

.chart-line {
  stroke: var(--cp-accent);
  stroke-width: 3;
  stroke-linecap: round;
  stroke-linejoin: round;
}

.chart-dot {
  fill: var(--cp-surface);
  stroke: var(--cp-accent);
  stroke-width: 3;
}

.chart-empty,
.loading-line,
.inline-error {
  color: var(--cp-text-muted);
}

.inline-error {
  padding: 14px;
  border-left: 4px solid var(--cp-danger);
  background: var(--cp-surface-soft);
}

.table-scroll {
  overflow-x: auto;
  border: 1px solid var(--cp-border);
  border-radius: 16px;
}

table {
  width: 100%;
  border-collapse: collapse;
  background: var(--cp-surface);
  font-size: 14px;
}

th,
td {
  padding: 12px 14px;
  border-bottom: 1px solid var(--cp-border);
  text-align: left;
  white-space: nowrap;
}

th {
  background: var(--cp-surface-soft);
  color: var(--cp-text-muted);
  font-size: 12px;
}

tbody tr:last-child td {
  border-bottom: 0;
}

.score-cell {
  color: var(--cp-accent);
  font-family: Consolas, "Courier New", Courier, monospace;
  font-weight: 800;
}

.table-empty {
  padding: 40px;
  color: var(--cp-text-muted);
  text-align: center;
}

.fatal-state {
  max-width: 680px;
  margin: 80px auto;
  padding: 28px;
  border: 1px solid var(--cp-danger);
  border-radius: 16px;
  background: var(--cp-surface);
}

.fatal-state h1 {
  margin-top: 0;
}

.modal-dialog {
  width: min(520px, calc(100vw - 32px));
  padding: 0;
  border: 1px solid var(--cp-border-strong);
  border-radius: 16px;
  background: var(--cp-surface);
  color: var(--cp-text);
  box-shadow: var(--cp-shadow);
}

.modal-dialog::backdrop {
  background: var(--cp-overlay);
}

.modal-dialog form {
  padding: 24px;
}

.modal-dialog h2 {
  margin: 0;
  font-size: 23px;
}

.modal-dialog p:not(.section-index) {
  color: var(--cp-text-muted);
}

.dialog-actions {
  justify-content: flex-end;
  margin-top: 24px;
}

.summary-score {
  display: flex;
  align-items: baseline;
  gap: 12px;
  margin-top: 22px;
}

.summary-score strong {
  color: var(--cp-accent);
  font-family: Consolas, "Courier New", Courier, monospace;
  font-size: 48px;
}

.summary-score span {
  color: var(--cp-text-muted);
}

.toast {
  position: fixed;
  z-index: 80;
  right: 24px;
  bottom: 24px;
  max-width: min(380px, calc(100vw - 48px));
  padding: 11px 15px;
  border: 1px solid var(--cp-border-strong);
  border-left: 5px solid var(--cp-accent);
  border-radius: 10px;
  background: var(--cp-panel-strong);
  color: var(--cp-text);
  box-shadow: var(--cp-shadow);
}

.toast[data-kind="warning"] {
  border-left-color: var(--cp-warning);
}

@media (max-width: 1120px) {
  .session-form {
    grid-template-columns: minmax(220px, 1.5fr) minmax(190px, 1fr) minmax(130px, 0.7fr);
  }

  .start-button {
    grid-column: 3;
  }

  .study-toolbar {
    grid-template-columns: auto minmax(140px, auto) minmax(100px, 1fr) auto;
  }

  .study-clock {
    grid-column: 2 / 4;
    grid-row: 2;
  }

  .study-actions {
    grid-column: 4;
    grid-row: 1 / 3;
  }
}

@media (max-width: 860px) {
  .app-shell {
    grid-template-columns: 82px minmax(0, 1fr);
  }

  .sidebar {
    padding-inline: 8px;
  }

  .nav-button,
  .text-button {
    justify-content: center;
    padding-inline: 6px;
    font-size: 12px;
  }

  .nav-button {
    flex-direction: column;
    gap: 3px;
  }

  .sidebar-footer .text-button span:last-child {
    display: none;
  }

  .vehicle-band {
    grid-template-columns: 1fr;
  }

  .vehicle-visual {
    max-height: 220px;
  }

  .stat-strip {
    grid-template-columns: repeat(2, 1fr);
  }

  .stat-strip article:nth-child(2) {
    border-right: 0;
  }

  .stat-strip article:nth-child(-n + 2) {
    border-bottom: 1px solid var(--cp-border);
  }

  .chapter-row {
    grid-template-columns: 44px minmax(0, 1fr) 42px;
  }

  .chapter-progress {
    grid-column: 2;
  }
}

@media (max-width: 700px) {
  .app-shell {
    display: block;
    padding-bottom: 72px;
  }

  .topbar {
    height: 60px;
    padding-inline: 12px;
  }

  .brand-mark {
    width: 36px;
    height: 36px;
  }

  .brand-copy small,
  .data-state,
  .global-timer .timer-divider,
  #global-countdown {
    display: none;
  }

  .global-timer {
    min-width: auto;
  }

  .sidebar {
    position: fixed;
    z-index: 30;
    top: auto;
    right: 0;
    bottom: 0;
    left: 0;
    width: 100%;
    height: 68px;
    display: block;
    padding: 6px max(8px, env(safe-area-inset-right)) max(6px, env(safe-area-inset-bottom)) max(8px, env(safe-area-inset-left));
    border-top: 1px solid var(--cp-border);
    border-right: 0;
  }

  .primary-nav {
    grid-template-columns: repeat(4, 1fr);
    gap: 4px;
  }

  .nav-button {
    min-height: 54px;
  }

  .sidebar-footer {
    display: none;
  }

  main {
    padding: 28px 16px 48px;
  }

  .view-heading,
  .section-heading {
    align-items: flex-start;
    flex-direction: column;
  }

  .view-heading h1 {
    font-size: 28px;
  }

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

  .heading-actions > * {
    flex: 1;
  }

  .vehicle-copy {
    padding: 24px 20px;
  }

  .vehicle-copy h2 {
    font-size: 24px;
  }

  .vehicle-visual,
  .vehicle-visual img {
    min-height: 180px;
  }

  .stat-strip article {
    padding: 16px;
  }

  .setup-section {
    padding: 20px 16px;
  }

  .session-form {
    grid-template-columns: 1fr 1fr;
  }

  .session-form .field-control:first-child {
    grid-column: 1 / -1;
  }

  .duration-field {
    grid-column: 1 / -1;
  }

  .start-button {
    grid-column: 1 / -1;
  }

  .chapter-row {
    gap: 10px;
  }

  .study-toolbar {
    position: static;
    grid-template-columns: auto minmax(0, 1fr) auto;
    border-radius: 10px;
  }

  .study-progress-track {
    grid-column: 1 / -1;
    grid-row: 2;
  }

  .study-clock {
    grid-column: 1 / 3;
    grid-row: 3;
  }

  .study-actions {
    grid-column: 3;
    grid-row: 1 / 4;
    flex-wrap: wrap;
    justify-content: flex-end;
  }

  .study-actions .secondary-button {
    width: 100%;
  }

  .question-workspace {
    margin-top: 30px;
  }

  #question-text {
    font-size: 21px;
  }

  .option-button {
    grid-template-columns: 34px minmax(0, 1fr);
    min-height: 56px;
    padding-inline: 11px;
  }

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

  .mistake-actions {
    justify-content: flex-end;
  }

  .history-summary {
    grid-template-columns: 1fr;
  }

  .history-summary article {
    border-right: 0;
    border-bottom: 1px solid var(--cp-border);
  }

  .history-summary article:last-child {
    border-bottom: 0;
  }

  .compact-field {
    grid-template-columns: 1fr;
  }

  .toast {
    right: 16px;
    bottom: 84px;
  }
}

@media (max-width: 430px) {
  .topbar-status {
    gap: 6px;
  }

  .stat-strip {
    grid-template-columns: 1fr;
  }

  .stat-strip article {
    border-right: 0;
    border-bottom: 1px solid var(--cp-border);
  }

  .stat-strip article:last-child {
    border-bottom: 0;
  }

  .session-form {
    grid-template-columns: 1fr;
  }

  .session-form > * {
    grid-column: 1 !important;
  }

  .study-toolbar {
    grid-template-columns: auto minmax(0, 1fr);
  }

  .study-actions {
    grid-column: 1 / -1;
    grid-row: 4;
    justify-content: flex-start;
  }

  .study-clock {
    grid-column: 1 / -1;
  }

  .multiple-submit,
  .question-footer,
  .dialog-actions {
    align-items: stretch;
    flex-direction: column;
  }

  .multiple-submit button,
  .question-footer button,
  .dialog-actions button {
    width: 100%;
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    scroll-behavior: auto !important;
    transition-duration: 0.01ms !important;
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
  }
}