:root {
  color-scheme: light;
  font-family: Inter, "PingFang SC", "Microsoft YaHei", Arial, sans-serif;
  background: #eef2f6;
  color: #142033;
  --line: #d7dee9;
  --muted: #667085;
  --panel: #ffffff;
  --green: #1b7f55;
  --blue: #255fbd;
  --red: #c13d36;
  --amber: #9a6700;
  --ink: #142033;
  --soft: #f7f9fc;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-width: 320px;
}

button,
input,
select {
  font: inherit;
}

button {
  border: 1px solid var(--line);
  background: #fff;
  color: var(--ink);
  border-radius: 6px;
  padding: 10px 12px;
  cursor: pointer;
}

button:hover {
  border-color: #7b8da5;
}

button:disabled {
  cursor: not-allowed;
  opacity: 0.55;
}

.primary {
  background: var(--blue);
  border-color: var(--blue);
  color: #fff;
}

.danger {
  border-color: var(--red);
  color: var(--red);
}

#app {
  display: grid;
  grid-template-columns: 236px minmax(0, 1fr);
  min-height: 100vh;
}

.sidebar {
  background: #fff;
  border-right: 1px solid var(--line);
  padding: 20px 16px;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.brand {
  display: grid;
  grid-template-columns: 44px 1fr;
  gap: 12px;
  align-items: center;
}

.brand-mark {
  display: grid;
  place-items: center;
  width: 44px;
  height: 44px;
  background: var(--green);
  color: #fff;
  border-radius: 7px;
  font-weight: 800;
}

.brand h1 {
  margin: 0;
  font-size: 17px;
  line-height: 1.25;
}

.brand p,
.side-stat span,
.eyebrow,
.muted,
.section-kicker {
  color: var(--muted);
}

.brand p {
  margin: 5px 0 0;
  font-size: 12px;
}

.nav {
  display: grid;
  gap: 8px;
}

.nav-button {
  text-align: left;
  background: #f8fafc;
  border-color: #e4eaf2;
  font-weight: 700;
}

.nav-button.active {
  background: #eaf5ef;
  color: #0f5132;
  border-color: #92ccb0;
}

.side-stat {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  border-top: 1px solid var(--line);
  padding-top: 14px;
}

.main {
  padding: 18px 22px 28px;
  min-width: 0;
}

.toolbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  margin-bottom: 10px;
}

.toolbar h2 {
  margin: 0;
  font-size: 26px;
}

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

.eyebrow,
.section-kicker {
  margin: 0 0 3px;
  text-transform: uppercase;
  letter-spacing: 0;
  font-size: 12px;
  font-weight: 800;
}

.notice {
  margin-bottom: 12px;
  padding: 12px 14px;
  border-radius: 6px;
  background: #e9f5ff;
  border: 1px solid #a9d7ff;
}

.notice.error {
  background: #fff0f0;
  border-color: #ffb4b4;
}

.notice.warn {
  background: #fff8e7;
  border-color: #f3cf72;
}

.study-drawer,
.filter-drawer {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 8px;
  margin-bottom: 10px;
}

.study-drawer > summary,
.filter-drawer > summary {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 11px 14px;
  cursor: pointer;
  font-weight: 800;
}

.study-drawer > summary strong {
  color: var(--blue);
  font-size: 13px;
}

.overview-board {
  display: grid;
  grid-template-columns: minmax(320px, 1.5fr) minmax(260px, 1fr) minmax(240px, 0.9fr);
  gap: 12px;
  padding: 0 14px 14px;
}

.plan-card,
.site-card,
.source-card,
.panel,
.metric,
.question-paper,
.source-box,
.queue-panel {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 8px;
  box-shadow: 0 1px 2px rgba(16, 24, 40, 0.04);
}

.plan-card,
.site-card,
.source-card,
.panel,
.question-paper,
.source-box,
.queue-panel {
  padding: 16px;
}

.plan-card h3,
.site-card h3,
.source-card h3,
.panel h3,
.queue-panel h3 {
  margin: 4px 0 10px;
}

.plan-list {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 9px;
}

.plan-step {
  border-left: 3px solid var(--green);
  background: #f4fbf7;
  padding: 9px 11px;
  border-radius: 6px;
}

.plan-step strong,
.plan-step span {
  display: block;
}

.plan-step span,
.feature-list,
.source-card p {
  color: #475467;
  line-height: 1.55;
  font-size: 14px;
}

.feature-list {
  margin: 0;
  padding-left: 18px;
}

.view {
  display: none;
}

.active-view {
  display: block;
}

.type-board {
  display: grid;
  grid-template-columns: repeat(3, minmax(170px, 1fr));
  gap: 9px;
  margin-bottom: 10px;
}

.type-button {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 3px 10px;
  align-items: center;
  min-height: 54px;
  text-align: left;
  background: #fff;
}

.type-button span {
  font-weight: 800;
}

.type-button strong {
  color: var(--blue);
  font-size: 18px;
}

.type-button small {
  grid-column: 1 / -1;
  color: var(--muted);
  font-size: 12px;
  display: none;
}

.type-button.active {
  border-color: var(--green);
  background: #eef8f2;
  box-shadow: inset 0 0 0 1px rgba(27, 127, 85, 0.12);
}

.mode-board {
  display: flex;
  gap: 9px;
  margin-bottom: 10px;
  overflow-x: auto;
  padding-bottom: 4px;
  scroll-snap-type: x proximity;
}

.mode-button {
  flex: 1 0 132px;
  text-align: left;
  display: grid;
  gap: 3px;
  min-height: 58px;
  background: #fff;
  scroll-snap-align: start;
}

.mode-button b,
.mode-button strong,
.mode-button span {
  display: block;
}

.mode-button strong {
  color: var(--blue);
  font-size: 17px;
  line-height: 1.15;
}

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

.mode-button.active {
  border-color: var(--blue);
  background: #edf4ff;
  box-shadow: inset 0 0 0 1px rgba(37, 95, 189, 0.12);
}

.chapter-drawer {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 8px;
  margin-bottom: 10px;
}

.chapter-drawer > summary {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  padding: 10px 12px;
  cursor: pointer;
  font-weight: 800;
}

.chapter-drawer > summary strong {
  color: var(--muted);
  font-size: 12px;
}

.chapter-list {
  display: flex;
  gap: 8px;
  overflow-x: auto;
  padding: 0 10px 10px;
  scroll-snap-type: x proximity;
}

.chapter-item {
  flex: 0 0 220px;
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 5px 8px;
  min-height: 66px;
  padding: 9px;
  text-align: left;
  scroll-snap-align: start;
}

.chapter-item span,
.chapter-item b,
.chapter-item small,
.chapter-item em,
.chapter-item i {
  display: block;
}

.chapter-item b {
  margin-bottom: 2px;
}

.chapter-item small,
.chapter-item em {
  color: var(--muted);
  font-size: 12px;
  font-style: normal;
}

.chapter-item strong {
  color: var(--red);
  font-size: 13px;
}

.chapter-item i {
  grid-column: 1 / -1;
  height: 5px;
  overflow: hidden;
  border-radius: 999px;
  background: #eef2f7;
}

.chapter-item mark {
  display: block;
  height: 100%;
  background: var(--green);
}

.chapter-item.active {
  border-color: var(--blue);
  background: #edf4ff;
}

.filters {
  display: grid;
  grid-template-columns: 100px repeat(4, minmax(120px, 1fr)) minmax(150px, 1fr) auto;
  gap: 10px;
  border: 0;
  box-shadow: none;
  padding-top: 0;
}

.filters label {
  display: grid;
  gap: 6px;
  font-size: 12px;
  color: #526070;
  font-weight: 800;
}

select,
input {
  width: 100%;
  border: 1px solid #c8d1dc;
  border-radius: 6px;
  padding: 10px;
  background: #fff;
  color: #172033;
}

.practice-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 248px;
  gap: 14px;
  align-items: start;
}

.question-panel {
  min-width: 0;
}

.question-paper {
  min-height: 560px;
}

.question-topline {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 14px;
  align-items: start;
  border-bottom: 1px solid #eef2f7;
  padding-bottom: 13px;
  margin-bottom: 16px;
}

.question-progress {
  border: 1px solid #bad0ef;
  border-radius: 6px;
  padding: 8px 10px;
  color: var(--blue);
  background: #f4f8ff;
  font-weight: 800;
  min-width: 58px;
  text-align: center;
}

.question-paper h3 {
  margin: 10px 0 0;
  line-height: 1.62;
  font-size: 22px;
  font-weight: 800;
}

.question-paper h3 p,
.analysis-body p {
  margin: 0 0 10px;
}

.question-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  color: var(--muted);
  font-size: 13px;
}

.question-meta span,
.meta-warn {
  display: inline-flex;
  align-items: center;
  border: 1px solid #dce5f1;
  background: #f8fafc;
  border-radius: 999px;
  padding: 4px 8px;
}

.question-meta .meta-warn {
  color: var(--amber);
  border-color: #efd48a;
  background: #fff8e7;
}

.question-meta .memory-chip {
  font-weight: 800;
}

.question-meta .memory-new {
  color: #475467;
}

.question-meta .memory-due {
  color: var(--red);
  border-color: #ffb4b4;
  background: #fff1f1;
}

.question-meta .memory-learning {
  color: var(--blue);
  border-color: #bad0ef;
  background: #f4f8ff;
}

.question-meta .memory-mastered {
  color: var(--green);
  border-color: #9ed8b5;
  background: #edf9f2;
}

.question-meta .bookmark-chip {
  color: var(--amber);
  border-color: #efd48a;
  background: #fff8e7;
  font-weight: 800;
}

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

.option {
  display: grid;
  grid-template-columns: 34px 1fr;
  gap: 12px;
  text-align: left;
  align-items: start;
  line-height: 1.6;
  padding: 13px 14px;
  min-height: 56px;
  border-color: #dbe3ef;
}

.option b {
  display: grid;
  place-items: center;
  width: 28px;
  height: 28px;
  background: #eef2f7;
  border-radius: 50%;
  color: #344054;
}

.option-text {
  min-width: 0;
  padding-top: 1px;
}

.option.locked {
  cursor: default;
}

.option.selected {
  border-color: var(--blue);
  background: #f4f8ff;
}

.option.correct-choice {
  border-color: #71c499;
  background: #edf9f2;
}

.option.correct-choice b {
  background: var(--green);
  color: #fff;
}

.option.wrong-choice {
  border-color: #ef9a9a;
  background: #fff1f1;
}

.option.wrong-choice b {
  background: var(--red);
  color: #fff;
}

.answer-row,
.button-row {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 16px;
}

.answer-row .marked {
  border-color: #efd48a;
  background: #fff8e7;
  color: var(--amber);
  font-weight: 800;
}

.answer-result {
  margin-top: 16px;
  padding: 15px;
  border-radius: 8px;
  line-height: 1.7;
}

.answer-result.correct {
  background: #edf9f2;
  border: 1px solid #9ed8b5;
}

.answer-result.wrong {
  background: #fff2f2;
  border: 1px solid #ffb4b4;
}

.answer-title {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  align-items: baseline;
  margin-bottom: 8px;
}

.answer-title h4 {
  margin: 0;
  font-size: 18px;
}

.answer-title span {
  color: #475467;
}

.analysis-body {
  color: #253044;
}

.analysis-muted {
  color: #5f6b7a;
}

.retry-answer {
  margin-top: 10px;
  background: #fff;
}

.source-box {
  margin-top: 10px;
  display: grid;
  gap: 8px;
  box-shadow: none;
}

.source-box div {
  display: grid;
  grid-template-columns: 76px 1fr;
  gap: 10px;
  color: #475467;
  font-size: 13px;
}

.source-box b {
  color: var(--ink);
}

.queue-panel {
  align-self: start;
  position: sticky;
  top: 14px;
}

.queue-panel p {
  margin: 0 0 12px;
  color: var(--muted);
}

.queue-toolbar {
  display: grid;
  grid-template-columns: 34px 1fr 34px;
  gap: 8px;
  align-items: center;
  margin-bottom: 12px;
}

.queue-toolbar button {
  padding: 6px 0;
  min-width: 0;
  font-size: 18px;
  line-height: 1;
}

.queue-toolbar span {
  color: #475467;
  font-size: 12px;
  font-weight: 800;
  text-align: center;
}

.queue-legend {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 6px 10px;
  margin-bottom: 12px;
  color: #5d6978;
  font-size: 12px;
}

.queue-legend span {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  white-space: nowrap;
}

.queue-legend i {
  display: inline-block;
  width: 10px;
  height: 10px;
  border: 1px solid var(--line);
  border-radius: 2px;
  background: #fff;
}

.queue-legend .legend-current {
  border-color: var(--blue);
  background: #f4f8ff;
}

.queue-legend .legend-ok {
  border-color: #9ed8b5;
  background: #eaf8f0;
}

.queue-legend .legend-bad {
  border-color: #ffb4b4;
  background: #fff0f0;
}

.question-queue {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 7px;
  max-height: 560px;
  overflow: auto;
}

.queue-item {
  padding: 8px 0;
  min-width: 0;
}

.queue-item.active {
  border-color: var(--blue);
  color: var(--blue);
  font-weight: 800;
  background: #f4f8ff;
}

.queue-item.ok {
  background: #eaf8f0;
}

.queue-item.bad {
  background: #fff0f0;
}

.table-wrap {
  overflow-x: auto;
  margin: 10px 0;
}

table {
  width: 100%;
  border-collapse: collapse;
  font-size: 14px;
}

th,
td {
  border: 1px solid var(--line);
  padding: 8px 10px;
  text-align: left;
  vertical-align: top;
}

th {
  background: #f3f6fa;
}

.stats-grid,
.data-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(140px, 1fr));
  gap: 14px;
  margin-bottom: 16px;
}

.data-grid {
  grid-template-columns: repeat(2, minmax(240px, 1fr));
}

.progress-preview {
  min-height: 72px;
  border: 1px dashed #c8d1dc;
  border-radius: 8px;
  padding: 10px;
  background: #fbfcfe;
  margin: 10px 0;
}

.progress-preview p {
  margin: 0;
}

.progress-preview-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(120px, 1fr));
  gap: 8px;
}

.progress-preview-grid span {
  display: grid;
  gap: 3px;
  color: #253044;
  font-size: 13px;
}

.progress-preview-grid b {
  color: var(--muted);
  font-size: 12px;
}

.metric {
  padding: 16px;
}

.metric span {
  display: block;
  color: var(--muted);
  margin-bottom: 8px;
}

.metric strong {
  font-size: 28px;
}

.stat-table {
  display: grid;
  gap: 8px;
}

.stat-row {
  display: grid;
  grid-template-columns: 1fr 80px 80px;
  gap: 10px;
  padding: 10px 0;
  border-bottom: 1px solid #eef2f7;
}

.item-list {
  display: grid;
  gap: 12px;
}

.item-card {
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 14px;
  background: #fbfcfe;
}

.item-card h4 {
  margin: 8px 0;
  line-height: 1.5;
}

.item-card p {
  line-height: 1.65;
}

.analysis {
  white-space: pre-wrap;
  background: #f4f6f8;
  border-radius: 6px;
  padding: 10px;
}

.file-button {
  display: inline-grid;
  place-items: center;
  border: 1px solid var(--line);
  background: #fff;
  border-radius: 6px;
  padding: 10px 12px;
  cursor: pointer;
}

.file-button input {
  display: none;
}

@media (max-width: 1180px) {
  .overview-board,
  .mode-board,
  .filters,
  .practice-layout,
  .stats-grid,
  .data-grid {
    grid-template-columns: 1fr;
  }

  .plan-list {
    grid-template-columns: 1fr;
  }

  .queue-panel {
    position: static;
  }
}

@media (max-width: 780px) {
  #app {
    grid-template-columns: 1fr;
  }

  .sidebar {
    position: static;
    padding: 12px 16px;
    gap: 10px;
  }

  .brand {
    grid-template-columns: 38px 1fr;
  }

  .brand-mark {
    width: 38px;
    height: 38px;
  }

  .brand h1 {
    font-size: 16px;
  }

  .brand p,
  .side-stat {
    display: none;
  }

  .nav {
    grid-template-columns: repeat(3, 1fr);
    gap: 7px;
  }

  .nav-button {
    padding: 9px 11px;
  }

  .main {
    padding: 12px 16px 18px;
  }

  .toolbar {
    align-items: center;
    flex-direction: row;
    gap: 10px;
  }

  .toolbar h2 {
    font-size: 22px;
  }

  .toolbar-actions .primary {
    padding: 9px 10px;
  }

  .study-drawer > summary,
  .filter-drawer > summary {
    align-items: flex-start;
    flex-direction: column;
  }

  .mode-board {
    display: flex;
    overflow-x: auto;
    padding-bottom: 4px;
    scroll-snap-type: x proximity;
  }

  .type-board {
    display: flex;
    overflow-x: auto;
    padding-bottom: 4px;
    scroll-snap-type: x proximity;
  }

  .type-button {
    flex: 0 0 206px;
    min-height: 54px;
    scroll-snap-align: start;
  }

  .mode-button {
    flex: 0 0 138px;
    min-height: 58px;
    scroll-snap-align: start;
  }

  .question-paper {
    min-height: auto;
    padding: 14px;
  }

  .question-topline {
    grid-template-columns: 1fr;
  }

  .question-progress {
    justify-self: start;
  }

  .question-paper h3 {
    font-size: 19px;
  }

  .option {
    grid-template-columns: 32px 1fr;
    padding: 12px;
  }

  .source-box div {
    grid-template-columns: 1fr;
    gap: 3px;
  }
}