:root {
  --ground: #F7F6F1;
  --ground-2: #EFEEE7;
  --panel: #FFFFFF;
  --ink: #14161C;
  --ink-2: #2E3340;
  --muted: #68707C;
  --muted-2: #8A8F98;
  --rule: #E2E1D8;
  --rule-strong: #7A7F87;
  --accent: #164FBF;
  --accent-deep: #0B2A6B;
  --accent-tint: #E7EEFB;
  --success: #0F6E4A;
  --success-tint: #E4F0E9;
  --alert: #9A3320;
  --alert-tint: #F5E8E4;
  --warning: #C08A2E;
  --warning-tint: #F5EEDD;

  --serif: Georgia, 'Iowan Old Style', 'Times New Roman', serif;
  --sans: -apple-system, BlinkMacSystemFont, 'Segoe UI', system-ui, 'Helvetica Neue', Arial, sans-serif;
  --mono: ui-monospace, 'SF Mono', Menlo, Consolas, 'Courier New', monospace;
}

* { box-sizing: border-box; }

html, body {
  background: var(--ground);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.55;
  margin: 0;
  padding: 0;
  -webkit-font-smoothing: antialiased;
}

.container {
  max-width: 780px;
  margin: 0 auto;
  padding: 40px 24px 80px;
}

a {
  color: var(--accent);
  text-decoration: none;
  border-bottom: 1px solid rgba(22, 79, 191, 0.25);
}
a:hover { color: var(--accent-deep); border-bottom-color: var(--accent-deep); }

.eyebrow {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--muted);
}

h1, h2, h3 { margin: 0; text-wrap: balance; }

/* ----------- Header ------------ */
.q-header {
  padding-bottom: 24px;
  border-bottom: 1px solid var(--rule);
  margin-bottom: 32px;
  display: flex;
  flex-direction: column;
  gap: 8px;
}
.q-crumb {
  display: flex;
  gap: 12px;
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--muted);
}
.q-crumb a { color: var(--muted); border: 0; }
.q-crumb a:hover { color: var(--ink); }
.q-crumb .sep::before { content: "·"; margin-right: 12px; color: var(--rule-strong); }
h1.q-title {
  font-family: var(--serif);
  font-weight: 400;
  font-size: clamp(28px, 4vw, 40px);
  line-height: 1.1;
  letter-spacing: -0.01em;
  color: var(--ink);
}
.q-subtitle {
  color: var(--ink-2);
  font-size: 15px;
  margin-top: 4px;
  max-width: 60ch;
}

/* ----------- Setup screen ------------ */
.setup-intro {
  color: var(--ink-2);
  margin-bottom: 24px;
  line-height: 1.6;
}
.setup-diff {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 12px;
  margin-bottom: 24px;
}
@media (max-width: 560px) { .setup-diff { grid-template-columns: 1fr; } }

.start-btn {
  background: var(--panel);
  border: 1px solid var(--rule-strong);
  padding: 18px 22px;
  cursor: pointer;
  text-align: left;
  font-family: var(--sans);
  color: var(--ink);
  transition: transform 80ms ease, border-color 120ms ease, background 120ms ease;
  display: flex;
  flex-direction: column;
  gap: 4px;
  border-radius: 2px;
}
.start-btn:hover {
  border-color: var(--accent);
  transform: translateY(-1px);
  background: #FCFCF8;
}
.start-btn:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}
.start-btn .btn-label {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--muted);
}
.start-btn .btn-title {
  font-family: var(--serif);
  font-size: 20px;
  color: var(--ink);
}
.start-btn .btn-count {
  font-family: var(--mono);
  font-size: 13px;
  color: var(--accent-deep);
  font-variant-numeric: tabular-nums;
  margin-top: 2px;
}
.start-btn.diff-easy { border-left: 3px solid var(--success); }
.start-btn.diff-medium { border-left: 3px solid var(--accent); }
.start-btn.diff-hard { border-left: 3px solid var(--alert); }
.start-btn.diff-all { border-left: 3px solid var(--ink); }

/* ----------- Cross-device sync ------------ */
.sync-panel {
  background: var(--panel);
  border: 1px solid var(--rule);
  border-left: 3px solid var(--accent);
  padding: 16px 18px;
  margin: -12px 0 32px;
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 16px;
  align-items: center;
  border-radius: 2px;
}
.sync-copy { display: flex; flex-direction: column; gap: 4px; }
.sync-status { color: var(--ink-2); font-size: 14px; line-height: 1.45; }
.sync-status.muted { color: var(--muted); }
.sync-status.ok { color: var(--success); }
.sync-status.error { color: var(--alert); }
.sync-form {
  display: flex;
  gap: 8px;
  align-items: center;
  flex-wrap: wrap;
  justify-content: flex-end;
}
.sync-form input {
  min-width: 180px;
  max-width: 240px;
  border: 1px solid var(--rule-strong);
  background: var(--ground);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 14px;
  padding: 10px 11px;
  border-radius: 2px;
}
.sync-form input:focus-visible,
.sync-form button:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }
.sync-form button {
  border: 1px solid var(--rule-strong);
  background: var(--panel);
  color: var(--ink);
  cursor: pointer;
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  padding: 11px 12px;
  border-radius: 2px;
}
.sync-form button:hover:not(:disabled) { border-color: var(--accent); color: var(--accent-deep); }
.sync-form button:disabled { cursor: wait; opacity: 0.6; }
@media (max-width: 720px) {
  .sync-panel { grid-template-columns: 1fr; }
  .sync-form { justify-content: flex-start; }
  .sync-form input { width: 100%; max-width: none; }
}

/* ----------- Quiz screen ------------ */
.q-progress {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 18px;
  font-family: var(--mono);
  font-size: 12px;
  color: var(--muted);
  font-variant-numeric: tabular-nums;
}
.progress-track {
  flex: 1;
  height: 3px;
  background: var(--rule);
  border-radius: 2px;
  overflow: hidden;
}
.progress-fill {
  height: 100%;
  background: var(--accent);
  transition: width 200ms ease;
}
.chip {
  display: inline-block;
  padding: 2px 10px;
  font-family: var(--mono);
  font-size: 10.5px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  border-radius: 2px;
  border: 1px solid var(--rule-strong);
  background: var(--panel);
}
.chip.diff-easy { color: var(--success); border-color: var(--success); background: var(--success-tint); }
.chip.diff-medium { color: var(--accent-deep); border-color: var(--accent); background: var(--accent-tint); }
.chip.diff-hard { color: var(--alert); border-color: var(--alert); background: var(--alert-tint); }

.q-card {
  background: var(--panel);
  border: 1px solid var(--rule);
  padding: 28px 30px 30px;
  border-radius: 3px;
}
.q-meta {
  display: flex;
  gap: 10px;
  align-items: center;
  margin-bottom: 12px;
}
.q-text {
  font-family: var(--serif);
  font-size: 22px;
  line-height: 1.35;
  color: var(--ink);
  margin-bottom: 22px;
  letter-spacing: -0.005em;
}

.q-options {
  display: flex;
  flex-direction: column;
  gap: 10px;
}
.option {
  background: var(--panel);
  border: 1px solid var(--rule-strong);
  padding: 14px 18px 14px 46px;
  cursor: pointer;
  text-align: left;
  font-family: var(--sans);
  font-size: 15px;
  color: var(--ink);
  line-height: 1.5;
  transition: border-color 120ms ease, background 120ms ease;
  position: relative;
  border-radius: 2px;
}
.option::before {
  content: attr(data-letter);
  position: absolute;
  left: 14px;
  top: 50%;
  transform: translateY(-50%);
  font-family: var(--mono);
  font-size: 12px;
  color: var(--muted);
  font-weight: 500;
  width: 22px;
  height: 22px;
  display: flex;
  align-items: center;
  justify-content: center;
  border: 1px solid var(--rule-strong);
  border-radius: 50%;
}
.option:hover:not(:disabled) {
  border-color: var(--accent);
  background: #FCFCF8;
}
.option:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }
.option:disabled { cursor: default; }
.option.correct {
  border-color: var(--success);
  background: var(--success-tint);
  color: var(--ink);
}
.option.correct::before {
  border-color: var(--success);
  background: var(--success);
  color: white;
}
.option.incorrect {
  border-color: var(--alert);
  background: var(--alert-tint);
}
.option.incorrect::before {
  border-color: var(--alert);
  background: var(--alert);
  color: white;
}
.option.selected:not(.correct):not(.incorrect) {
  border-color: var(--accent);
  background: var(--accent-tint);
}

.feedback {
  margin-top: 20px;
  padding: 16px 18px;
  border-radius: 2px;
  border-left: 3px solid;
  display: none;
}
.feedback.correct {
  background: var(--success-tint);
  border-left-color: var(--success);
}
.feedback.incorrect {
  background: var(--alert-tint);
  border-left-color: var(--alert);
}
.feedback-verdict {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  font-weight: 600;
  margin-bottom: 6px;
}
.feedback.correct .feedback-verdict { color: var(--success); }
.feedback.incorrect .feedback-verdict { color: var(--alert); }
.feedback-explanation {
  font-size: 14.5px;
  color: var(--ink-2);
  line-height: 1.55;
}

.q-controls {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 12px;
  margin-top: 20px;
}
.btn {
  background: var(--ink);
  color: white;
  border: 1px solid var(--ink);
  padding: 10px 20px;
  font-family: var(--sans);
  font-size: 14px;
  cursor: pointer;
  transition: opacity 120ms ease, background 120ms ease;
  border-radius: 2px;
  font-weight: 500;
}
.btn:hover { background: var(--ink-2); }
.btn:disabled { opacity: 0.4; cursor: default; }
.btn-secondary {
  background: transparent;
  color: var(--ink);
  border: 1px solid var(--rule-strong);
}
.btn-secondary:hover { background: var(--ground-2); border-color: var(--ink); }
.btn-primary {
  background: var(--accent);
  color: white;
  border-color: var(--accent);
}
.btn-primary:hover { background: var(--accent-deep); border-color: var(--accent-deep); }
.btn:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }

/* ----------- Results screen ------------ */
.results-hero {
  background: var(--panel);
  border: 1px solid var(--rule);
  padding: 36px 32px 40px;
  text-align: center;
  border-radius: 3px;
  margin-bottom: 24px;
}
.score-pct {
  font-family: var(--mono);
  font-size: 72px;
  line-height: 1;
  color: var(--ink);
  font-variant-numeric: tabular-nums;
  letter-spacing: -0.04em;
  font-weight: 500;
}
.score-fraction {
  font-family: var(--mono);
  font-size: 14px;
  color: var(--muted);
  margin-top: 12px;
  font-variant-numeric: tabular-nums;
}
.verdict {
  margin-top: 20px;
  font-family: var(--serif);
  font-size: 22px;
  line-height: 1.3;
}
.verdict.great { color: var(--success); }
.verdict.good { color: var(--accent-deep); }
.verdict.ok { color: var(--warning); }
.verdict.low { color: var(--alert); }

.results-actions {
  display: flex;
  gap: 12px;
  justify-content: center;
  margin-bottom: 32px;
}

/* ----------- Progress journal ------------ */
.progress-journal {
  margin: 40px 0 48px;
  padding: 28px 0 34px;
  border-top: 2px solid var(--ink);
  border-bottom: 1px solid var(--rule-strong);
}
.journal-header {
  display: flex;
  justify-content: space-between;
  gap: 24px;
  margin-bottom: 28px;
}
.journal-header h2 {
  margin: 2px 0 8px;
  color: var(--ink);
  font-family: var(--serif);
  font-size: clamp(25px, 4vw, 32px);
  font-weight: 400;
  line-height: 1.15;
}
.journal-header p {
  max-width: 62ch;
  margin: 0;
  color: var(--ink-2);
  font-size: 14.5px;
  line-height: 1.55;
}
.journal-grid {
  display: grid;
  grid-template-columns: minmax(220px, 0.8fr) minmax(0, 1.35fr);
  gap: 32px;
  align-items: start;
}
.journal-section-head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 16px;
  margin-bottom: 14px;
  padding-bottom: 9px;
  border-bottom: 1px solid var(--rule);
}
.journal-section-head h3 {
  margin: 0;
  color: var(--ink);
  font-family: var(--serif);
  font-size: 19px;
  font-weight: 400;
}
.journal-section-head span {
  color: var(--muted);
  font-family: var(--mono);
  font-size: 11px;
  white-space: nowrap;
}
.completion-list {
  margin: 0;
  padding: 0;
  list-style: none;
}
.completion-item {
  display: grid;
  grid-template-columns: 34px minmax(0, 1fr) auto;
  gap: 10px;
  align-items: start;
  padding: 13px 0;
  border-bottom: 1px solid var(--rule);
}
.completion-item:first-child { padding-top: 2px; }
.completion-code {
  color: var(--accent-deep);
  font-family: var(--mono);
  font-size: 11px;
  font-weight: 600;
}
.completion-copy { min-width: 0; }
.completion-copy strong {
  display: block;
  color: var(--ink);
  font-family: var(--serif);
  font-size: 15px;
  font-weight: 400;
  line-height: 1.3;
}
.completion-copy > span {
  display: block;
  margin-top: 4px;
  color: var(--muted);
  font-size: 11px;
  line-height: 1.45;
}
.completion-score {
  color: var(--ink);
  font-family: var(--mono);
  font-size: 19px;
  line-height: 1;
  text-align: right;
}
.completion-score small {
  display: block;
  margin-top: 5px;
  color: var(--muted);
  font-size: 10px;
}
.mistake-search {
  display: block;
  margin-bottom: 14px;
}
.mistake-search span {
  display: block;
  margin-bottom: 6px;
  color: var(--ink-2);
  font-size: 12px;
  font-weight: 600;
}
.mistake-search input {
  width: 100%;
  min-height: 44px;
  border: 1px solid var(--rule-strong);
  border-radius: 2px;
  background: var(--panel);
  color: var(--ink);
  padding: 10px 12px;
  font-size: 14px;
}
.mistake-search input:focus-visible,
.mistake-item summary:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}
.mistake-item {
  border-bottom: 1px solid var(--rule);
  background: var(--panel);
}
.mistake-item:first-child { border-top: 1px solid var(--rule); }
.mistake-item summary {
  display: grid;
  grid-template-columns: 38px minmax(0, 1fr) auto;
  gap: 10px;
  align-items: baseline;
  min-height: 48px;
  padding: 12px;
  cursor: pointer;
  list-style: none;
}
.mistake-item summary::-webkit-details-marker { display: none; }
.mistake-item summary::after {
  content: '+';
  grid-column: 3;
  grid-row: 1;
  margin-left: 8px;
  color: var(--ink-2);
  font-family: var(--mono);
}
.mistake-item[open] summary::after { content: '−'; }
.mistake-item[open] summary { background: var(--ground-2); }
.mistake-code {
  color: var(--alert);
  font-family: var(--mono);
  font-size: 11px;
  font-weight: 600;
}
.mistake-question {
  grid-column: 2;
  color: var(--ink);
  font-family: var(--serif);
  font-size: 15px;
  line-height: 1.4;
}
.mistake-frequency {
  grid-column: 2;
  color: var(--muted);
  font-family: var(--mono);
  font-size: 10px;
  letter-spacing: 0.04em;
}
.mistake-detail {
  padding: 4px 12px 16px 60px;
  color: var(--ink-2);
  font-size: 13.5px;
  line-height: 1.5;
}
.mistake-detail p { margin: 0 0 7px; }
.mistake-meta { color: var(--muted); font-size: 11px; }
.mistake-answer.wrong strong { color: var(--alert); }
.mistake-answer.right strong { color: var(--success); }
.mistake-explanation {
  margin-top: 11px !important;
  padding-top: 10px;
  border-top: 1px dashed var(--rule-strong);
}
.journal-empty,
.journal-loading {
  margin: 0;
  padding: 16px;
  border: 1px dashed var(--rule-strong);
  background: var(--panel);
  color: var(--ink-2);
  font-size: 13px;
  line-height: 1.5;
}

@media (max-width: 680px) {
  .progress-journal { margin: 32px 0 40px; padding: 24px 0 28px; }
  .journal-grid { grid-template-columns: 1fr; gap: 30px; }
  .completion-item { grid-template-columns: 32px minmax(0, 1fr) auto; }
  .mistake-item summary { grid-template-columns: 32px minmax(0, 1fr) auto; padding: 12px 8px; }
  .mistake-detail { padding: 4px 8px 16px 50px; }
}

.review-title {
  font-family: var(--serif);
  font-size: 24px;
  margin-bottom: 16px;
  color: var(--ink);
}
.review-item {
  background: var(--panel);
  border: 1px solid var(--rule);
  border-left-width: 3px;
  padding: 16px 18px;
  margin-bottom: 10px;
  border-radius: 2px;
}
.review-item.correct { border-left-color: var(--success); }
.review-item.incorrect { border-left-color: var(--alert); }
.review-header {
  display: flex;
  gap: 10px;
  align-items: center;
  font-family: var(--mono);
  font-size: 11px;
  color: var(--muted);
  margin-bottom: 8px;
}
.review-num {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.14em;
}
.review-verdict {
  margin-left: auto;
  font-size: 14px;
  font-weight: 600;
}
.review-item.correct .review-verdict { color: var(--success); }
.review-item.incorrect .review-verdict { color: var(--alert); }
.review-q {
  font-family: var(--serif);
  font-size: 16px;
  color: var(--ink);
  margin-bottom: 8px;
  line-height: 1.4;
}
.review-a {
  font-size: 14px;
  color: var(--ink-2);
  margin-bottom: 4px;
}
.review-a strong { color: var(--success); }
.review-y {
  font-size: 14px;
  color: var(--alert);
  margin-bottom: 4px;
}
.review-e {
  font-size: 13.5px;
  color: var(--muted);
  margin-top: 8px;
  padding-top: 8px;
  border-top: 1px dashed var(--rule);
  line-height: 1.5;
}

/* ----------- Index page ------------ */
.index-hero {
  padding-bottom: 32px;
  border-bottom: 1px solid var(--rule);
  margin-bottom: 40px;
}
.index-hero h1 {
  font-family: var(--serif);
  font-weight: 400;
  font-size: clamp(32px, 5vw, 48px);
  line-height: 1.05;
  letter-spacing: -0.015em;
  margin-bottom: 12px;
}
.index-hero h1 em { font-style: italic; color: var(--accent-deep); }
.index-hero p {
  color: var(--ink-2);
  font-size: 16px;
  max-width: 60ch;
  line-height: 1.55;
}

.domain-group {
  margin-bottom: 40px;
}
.domain-heading {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--rule);
  margin-bottom: 16px;
}
.domain-heading h2 {
  font-family: var(--serif);
  font-weight: 400;
  font-size: 22px;
  color: var(--ink);
}
.domain-heading .weight {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--muted);
}
.quiz-list {
  display: flex;
  flex-direction: column;
}
.quiz-item {
  display: flex;
  align-items: baseline;
  padding: 14px 4px;
  border-bottom: 1px solid var(--rule);
  gap: 16px;
  text-decoration: none;
  color: var(--ink);
  border-bottom-width: 1px;
}
.quiz-item:hover { background: var(--ground-2); border-bottom-color: var(--accent); }
.quiz-item .num {
  font-family: var(--mono);
  font-size: 13px;
  color: var(--muted);
  font-variant-numeric: tabular-nums;
  min-width: 32px;
}
.quiz-item .title {
  flex: 1;
  font-family: var(--serif);
  font-size: 17px;
  color: var(--ink);
}
.quiz-score {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--success);
  white-space: nowrap;
}
.quiz-item .arrow {
  font-family: var(--mono);
  color: var(--muted);
  transition: transform 120ms ease, color 120ms ease;
}
.quiz-item:hover .arrow { color: var(--accent); transform: translateX(3px); }

footer.page-footer {
  margin-top: 60px;
  padding-top: 24px;
  border-top: 1px solid var(--rule);
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--muted);
  text-align: center;
}

@media (prefers-reduced-motion: reduce) {
  * { transition: none !important; animation: none !important; }
}