:root {
  color-scheme: light;
  --bg: #f5f7fa;
  --panel: #ffffff;
  --text: #20242a;
  --muted: #667085;
  --line: #d9e0e8;
  --accent: #0f766e;
  --accent-strong: #0b5f59;
  --accent-soft: #e4f5f2;
  --correct: #138a4b;
  --correct-soft: #e8f7ef;
  --wrong: #c2412f;
  --wrong-soft: #fff0ed;
  --focus: #f59e0b;
  --select-chevron: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='16' height='16' viewBox='0 0 24 24' fill='none' stroke='%23667085' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpolyline points='6 9 12 15 18 9'/%3E%3C/svg%3E");
}

* {
  box-sizing: border-box;
}

html,
body {
  height: 100%;
}

body {
  margin: 0;
  overflow: hidden;
  background: var(--bg);
  color: var(--text);
  font-family:
    Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI",
    "PingFang SC", "Microsoft YaHei", sans-serif;
  letter-spacing: 0;
}

button {
  font: inherit;
}

.app-shell {
  display: flex;
  flex-direction: column;
  width: min(100%, 1240px);
  height: 100%;
  margin: 0 auto;
  padding: 28px 18px;
  overflow: hidden;
}

.app-header {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: 18px;
  margin-bottom: 18px;
  flex-shrink: 0;
}

.eyebrow {
  margin: 0 0 6px;
  color: var(--accent);
  font-size: 13px;
  font-weight: 700;
  text-transform: uppercase;
}

h1,
h2,
h3,
p {
  margin-top: 0;
}

h1 {
  margin-bottom: 0;
  font-size: 32px;
  line-height: 1.15;
}

.score-strip {
  display: flex;
  flex-wrap: wrap;
  justify-content: flex-end;
  gap: 8px;
  color: var(--muted);
  font-size: 14px;
}

.score-strip span,
.meta-row span {
  min-height: 32px;
  display: inline-flex;
  align-items: center;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: var(--panel);
  padding: 0 12px;
  white-space: nowrap;
}

.toolbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 14px;
  flex-shrink: 0;
}

.subject-tabs {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.toolbar-actions {
  display: flex;
  align-items: center;
  gap: 8px;
}

.tab-button,
.ghost-button,
.primary-button,
.option-button {
  min-height: 44px;
  border-radius: 8px;
  border: 1px solid var(--line);
  cursor: pointer;
  transition:
    background 160ms ease,
    border-color 160ms ease,
    color 160ms ease,
    transform 160ms ease;
}

.tab-button,
.ghost-button {
  background: var(--panel);
  color: var(--text);
  padding: 0 14px;
}

.type-select,
.field select {
  appearance: none;
  -webkit-appearance: none;
  min-height: 40px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background-color: #ffffff;
  background-image: var(--select-chevron);
  background-repeat: no-repeat;
  background-position: right 12px center;
  background-size: 16px;
  color: var(--text);
  font: inherit;
  line-height: 1.2;
  padding: 0 36px 0 12px;
  cursor: pointer;
  transition:
    background-color 160ms ease,
    border-color 160ms ease,
    color 160ms ease;
}

.type-select {
  min-height: 44px;
  width: auto;
  min-width: 132px;
  background-color: var(--panel);
}

.field select {
  width: 100%;
}

.tab-button:hover,
.ghost-button:hover {
  border-color: var(--accent);
  color: var(--accent-strong);
}

.type-select:hover,
.field select:hover {
  border-color: var(--accent);
  color: var(--accent-strong);
}

.tab-button.is-active {
  border-color: var(--accent);
  background: var(--accent-soft);
  color: var(--accent-strong);
}

.practice-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 340px;
  align-items: stretch;
  flex: 1;
  min-height: 0;
  gap: 14px;
}

.practice-view,
.navigator-panel,
.result-view {
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--panel);
  padding: 22px;
}

.practice-view {
  min-height: 0;
  overflow-y: auto;
}

.navigator-panel {
  display: flex;
  flex-direction: column;
  min-height: 0;
  height: 100%;
  overflow: hidden;
}

.navigator-summary {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 14px;
  cursor: pointer;
  font-size: 22px;
  font-weight: 800;
  list-style: none;
}

.navigator-summary::-webkit-details-marker {
  display: none;
}

.navigator-summary::after {
  content: "";
  width: 10px;
  height: 10px;
  border-right: 2px solid var(--muted);
  border-bottom: 2px solid var(--muted);
  transform: rotate(45deg) translateY(-2px);
  transition: transform 160ms ease;
}

.navigator-panel[open] .navigator-summary::after {
  transform: rotate(225deg) translate(-2px, -2px);
}

.navigator-content {
  display: flex;
  flex: 1;
  min-height: 0;
  flex-direction: column;
}

.panel-header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 14px;
  flex-shrink: 0;
}

.panel-header h2 {
  margin-bottom: 0;
  font-size: 22px;
}

#filteredCountText {
  min-height: 30px;
  display: inline-flex;
  align-items: center;
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: 0 10px;
  color: var(--muted);
  font-size: 13px;
  white-space: nowrap;
}

.control-grid {
  display: grid;
  gap: 10px;
  margin-bottom: 12px;
  flex-shrink: 0;
}

.field {
  display: grid;
  gap: 5px;
  color: var(--muted);
  font-size: 13px;
  font-weight: 700;
}

.field input {
  width: 100%;
  min-height: 40px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #ffffff;
  color: var(--text);
  font: inherit;
  padding: 0 12px;
}

.field input:focus-visible,
.field select:focus-visible,
.type-select:focus-visible {
  outline: 3px solid var(--focus);
  outline-offset: 2px;
}

.navigator-actions {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
  margin-bottom: 12px;
  flex-shrink: 0;
}

.checkbox-control {
  min-height: 40px;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  color: var(--text);
  font-size: 14px;
}

.checkbox-control input {
  width: 18px;
  height: 18px;
  accent-color: var(--accent);
}

.question-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(42px, 1fr));
  gap: 7px;
  flex: 1;
  min-height: 0;
  overflow-y: auto;
  align-content: start;
}

.question-jump-button {
  min-width: 0;
  min-height: 38px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #ffffff;
  color: var(--text);
  cursor: pointer;
  font-size: 13px;
  font-weight: 700;
}

.question-jump-button:hover {
  border-color: var(--accent);
}

.question-jump-button.is-current {
  border-color: var(--accent);
  outline: 2px solid var(--accent-soft);
}

.question-jump-button.is-unanswered {
  background: #ffffff;
}

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

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

.question-tooltip {
  position: fixed;
  z-index: 1000;
  max-width: min(320px, calc(100vw - 24px));
  border-radius: 8px;
  padding: 10px 12px;
  background: #20242a;
  color: #ffffff;
  box-shadow: 0 10px 28px rgba(16, 24, 40, 0.2);
  pointer-events: none;
}

.question-tooltip__meta {
  margin: 0 0 6px;
  color: #cbd5df;
  font-size: 12px;
  line-height: 1.4;
}

.question-tooltip__text {
  margin: 0;
  font-size: 13px;
  line-height: 1.55;
  overflow-wrap: anywhere;
}

.empty-state {
  margin-bottom: 0;
  color: var(--muted);
  font-size: 14px;
}

.meta-row {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 20px;
  color: var(--muted);
  font-size: 14px;
}

.question-area h2 {
  margin-bottom: 10px;
  font-size: 22px;
  line-height: 1.55;
}

.source-text {
  margin-bottom: 18px;
  color: var(--muted);
  font-size: 14px;
}

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

.option-button {
  width: 100%;
  display: grid;
  grid-template-columns: 34px 1fr;
  align-items: start;
  gap: 10px;
  border-color: var(--line);
  background: #ffffff;
  padding: 14px;
  color: var(--text);
  text-align: left;
}

.option-button:hover:not(:disabled) {
  border-color: var(--accent);
  background: #f9fffd;
}

.option-button:focus-visible,
.tab-button:focus-visible,
.ghost-button:focus-visible,
.type-select:focus-visible,
.primary-button:focus-visible {
  outline: 3px solid var(--focus);
  outline-offset: 2px;
}

.option-button:disabled {
  cursor: default;
}

.option-label {
  width: 34px;
  height: 28px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: 999px;
  background: #edf1f5;
  color: var(--muted);
  font-weight: 800;
}

.option-text {
  min-width: 0;
  line-height: 1.55;
  overflow-wrap: anywhere;
}

.option-button.is-selected {
  border-color: var(--accent);
  background: var(--accent-soft);
}

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

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

.option-button.is-correct .option-label {
  background: var(--correct);
  color: #ffffff;
}

.option-button.is-wrong .option-label {
  background: var(--wrong);
  color: #ffffff;
}

.action-row {
  display: flex;
  justify-content: flex-end;
  gap: 10px;
  margin-top: 18px;
}

.primary-button {
  border-color: var(--accent);
  background: var(--accent);
  color: #ffffff;
  padding: 0 18px;
  font-weight: 700;
}

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

.primary-button:disabled {
  border-color: #cbd5df;
  background: #d7dee6;
  color: #7b8794;
  cursor: not-allowed;
}

.feedback-box {
  margin-top: 18px;
  border: 1px solid var(--line);
  border-left-width: 5px;
  border-radius: 8px;
  padding: 16px;
  background: #ffffff;
}

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

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

.feedback-box h3 {
  margin-bottom: 8px;
  font-size: 18px;
}

.feedback-box p {
  margin-bottom: 6px;
  line-height: 1.6;
}

.result-summary {
  margin-bottom: 16px;
}

.result-summary h2 {
  margin-bottom: 8px;
  font-size: 28px;
}

.type-stats {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
  gap: 10px;
  margin-bottom: 18px;
}

.stat-item {
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 12px;
  background: #fbfcfe;
}

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

.wrong-list {
  display: grid;
  gap: 10px;
  margin-bottom: 18px;
}

.wrong-item {
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 12px;
  background: #ffffff;
}

.wrong-item p {
  margin-bottom: 6px;
  line-height: 1.55;
}

[hidden] {
  display: none !important;
}

@media (max-width: 720px) {
  html,
  body {
    height: 100%;
    overflow: hidden;
  }

  body {
    background: #f3f6f8;
  }

  .app-shell {
    width: 100%;
    height: 100dvh;
    min-height: 0;
    gap: 8px;
    padding: calc(env(safe-area-inset-top) + 10px) 10px calc(env(safe-area-inset-bottom) + 10px);
    overflow: hidden;
  }

  .app-header {
    display: grid;
    grid-template-columns: auto minmax(0, 1fr);
    align-items: center;
    gap: 8px;
    margin-bottom: 0;
  }

  .eyebrow {
    display: none;
  }

  h1 {
    font-size: 22px;
    line-height: 1.15;
  }

  .score-strip {
    justify-content: flex-end;
    gap: 5px;
    font-size: 12px;
  }

  .score-strip span,
  .meta-row span,
  #filteredCountText {
    min-height: 26px;
    padding: 0 8px;
    border-radius: 7px;
    background: #ffffff;
  }

  .toolbar {
    display: grid;
    gap: 7px;
    margin-bottom: 0;
  }

  .subject-tabs {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 3px;
    border: 1px solid var(--line);
    border-radius: 8px;
    background: #ffffff;
    padding: 3px;
  }

  .tab-button {
    min-height: 34px;
    border: 0;
    border-radius: 6px;
    background: transparent;
    padding: 0 6px;
    font-size: 14px;
    font-weight: 700;
  }

  .tab-button.is-active {
    background: var(--accent-soft);
    box-shadow: inset 0 0 0 1px var(--accent);
  }

  .toolbar-actions {
    display: grid;
    grid-template-columns: minmax(0, 1fr) 88px;
    gap: 7px;
  }

  .type-select,
  .toolbar-actions .ghost-button {
    min-height: 36px;
    width: 100%;
    border-radius: 8px;
    font-size: 14px;
  }

  .toolbar-actions .ghost-button {
    padding: 0 8px;
  }

  .practice-layout {
    grid-template-columns: 1fr;
    grid-template-rows: minmax(0, 1fr);
    flex: 1;
    min-height: 0;
    gap: 8px;
    padding-bottom: 82px;
    position: relative;
  }

  .practice-view,
  .navigator-panel,
  .result-view {
    border-radius: 8px;
    padding: 12px;
  }

  .practice-view {
    display: flex;
    min-height: 0;
    margin-bottom: 8px;
    overflow: hidden;
    flex-direction: column;
  }

  .meta-row {
    gap: 5px;
    margin-bottom: 9px;
    font-size: 12px;
  }

  .question-area {
    min-height: 0;
    overflow-y: auto;
    padding-right: 2px;
    -webkit-overflow-scrolling: touch;
  }

  .question-area h2 {
    margin-bottom: 7px;
    font-size: 18px;
    line-height: 1.42;
  }

  .source-text {
    margin-bottom: 10px;
    font-size: 12px;
    line-height: 1.45;
  }

  .options-list {
    gap: 7px;
  }

  .option-button {
    min-height: 50px;
    grid-template-columns: 30px 1fr;
    gap: 8px;
    padding: 10px;
    border-radius: 8px;
  }

  .option-label {
    width: 30px;
    height: 26px;
    font-size: 14px;
  }

  .option-text {
    font-size: 15px;
    line-height: 1.45;
  }

  .action-row {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 7px;
    margin-top: 9px;
    padding-top: 9px;
    border-top: 1px solid var(--line);
    background: var(--panel);
  }

  .action-row .primary-button,
  .action-row .ghost-button {
    min-height: 42px;
    width: 100%;
    padding: 0 10px;
    border-radius: 8px;
    font-size: 15px;
  }

  .action-row #confirmButton:not([hidden]) {
    grid-column: 1 / -1;
  }

  .feedback-box {
    max-height: 22dvh;
    margin-top: 8px;
    overflow-y: auto;
    padding: 10px 12px;
    border-radius: 8px;
    font-size: 14px;
    -webkit-overflow-scrolling: touch;
  }

  .feedback-box h3 {
    margin-bottom: 4px;
    font-size: 16px;
  }

  .feedback-box p {
    margin-bottom: 3px;
    line-height: 1.5;
  }

  .navigator-panel {
    display: block;
    position: fixed;
    z-index: 20;
    right: 10px;
    bottom: calc(env(safe-area-inset-bottom) + 16px);
    left: 10px;
    height: auto;
    min-height: 0;
    max-height: 58dvh;
    overflow: hidden;
    box-shadow:
      0 -8px 22px rgba(32, 36, 42, 0.06),
      0 14px 34px rgba(32, 36, 42, 0.16);
  }

  .navigator-summary {
    min-height: 38px;
    margin-bottom: 0;
    font-size: 15px;
  }

  .navigator-panel[open] .navigator-summary {
    margin-bottom: 10px;
  }

  .navigator-content {
    min-height: 0;
    max-height: calc(58dvh - 58px);
    overflow: hidden;
  }

  .control-grid {
    grid-template-columns: minmax(0, 1fr) minmax(0, 0.8fr);
    gap: 8px;
    margin-bottom: 8px;
  }

  .field {
    gap: 4px;
    font-size: 12px;
  }

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

  .field input,
  .field select {
    min-height: 36px;
    border-radius: 8px;
    font-size: 14px;
  }

  .field input:focus-visible,
  .field select:focus-visible,
  .type-select:focus-visible {
    outline: 0;
    border-color: var(--focus);
    box-shadow: inset 0 0 0 2px var(--focus);
  }

  .navigator-actions {
    display: grid;
    grid-template-columns: minmax(0, 1fr) 96px;
    align-items: center;
    gap: 8px;
    margin-bottom: 8px;
  }

  .navigator-actions .ghost-button {
    min-height: 36px;
    width: 100%;
    padding: 0 8px;
    border-radius: 8px;
    font-size: 14px;
  }

  .checkbox-control {
    min-height: 36px;
    font-size: 14px;
  }

  .question-grid {
    grid-template-columns: repeat(auto-fill, minmax(38px, 1fr));
    gap: 6px;
    max-height: 18dvh;
    overflow-y: auto;
    -webkit-overflow-scrolling: touch;
  }

  .question-jump-button {
    min-height: 34px;
    border-radius: 8px;
    font-size: 13px;
  }

  .result-view {
    min-height: 0;
    overflow-y: auto;
  }
}