:root {
  color-scheme: light;
  --ink: #17212b;
  --muted: #64717f;
  --line: #d8e0e7;
  --paper: #f7f4ed;
  --panel: #ffffff;
  --accent: #106b72;
  --accent-2: #c4552d;
  --good: #1d7a50;
  --bad: #b33a32;
  --warn: #9b6b14;
  --shadow: 0 16px 45px rgba(24, 39, 55, 0.12);
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  color: var(--ink);
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  background:
    linear-gradient(180deg, rgba(16, 107, 114, 0.12), transparent 360px),
    repeating-linear-gradient(135deg, rgba(16, 107, 114, 0.055) 0 2px, transparent 2px 18px),
    var(--paper);
}

.signature {
  position: fixed;
  right: 14px;
  bottom: 10px;
  z-index: 10;
  color: rgba(100, 113, 127, 0.72);
  font-size: 11px;
  font-weight: 700;
  pointer-events: none;
}

button,
input,
textarea {
  font: inherit;
}

button {
  min-height: 42px;
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 0 14px;
  cursor: pointer;
  background: var(--panel);
  color: var(--ink);
}

button:disabled {
  cursor: not-allowed;
  opacity: 0.45;
}

.primary {
  border-color: var(--accent);
  background: var(--accent);
  color: white;
  font-weight: 700;
}

.secondary {
  background: #fdfbf7;
}

.topbar {
  display: flex;
  align-items: end;
  justify-content: space-between;
  gap: 20px;
  padding: 28px clamp(16px, 4vw, 42px) 20px;
}

h1,
h2,
p {
  margin: 0;
}

h1 {
  font-size: 34px;
  line-height: 1.05;
}

h2 {
  font-size: 17px;
}

.eyebrow {
  color: var(--muted);
  font-size: 12px;
  font-weight: 800;
  letter-spacing: 0;
  text-transform: uppercase;
}

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

.stats span,
.timer {
  border: 1px solid rgba(16, 107, 114, 0.22);
  border-radius: 999px;
  padding: 8px 12px;
  background: rgba(255, 255, 255, 0.72);
  color: var(--accent);
  font-weight: 800;
}

.layout {
  display: grid;
  grid-template-columns: minmax(230px, 280px) minmax(0, 1fr) minmax(230px, 300px);
  gap: 18px;
  padding: 0 clamp(16px, 4vw, 42px) 34px;
}

.panel,
.question-card,
.sessionbar {
  border: 1px solid rgba(28, 42, 55, 0.12);
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.86);
  box-shadow: var(--shadow);
}

.panel {
  align-self: start;
  padding: 16px;
}

.controls,
.review {
  display: grid;
  gap: 18px;
}

.segmented {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 4px;
  padding: 4px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #eef3f2;
  margin-top: 10px;
}

.segmented button {
  border: 0;
  background: transparent;
}

.segmented button.active {
  background: var(--panel);
  color: var(--accent);
  box-shadow: 0 1px 6px rgba(0, 0, 0, 0.08);
}

.theme-list {
  display: grid;
  gap: 6px;
  margin-top: 10px;
  max-height: 330px;
  overflow: auto;
  padding-right: 4px;
}

.theme-actions {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 8px;
  margin-top: 10px;
}

.theme-actions button {
  min-height: 34px;
  padding: 0 8px;
  font-size: 12px;
  font-weight: 800;
}

.theme {
  display: grid;
  grid-template-columns: 18px minmax(0, 1fr) auto;
  gap: 8px;
  align-items: center;
  font-size: 13px;
  color: var(--muted);
}

.theme strong {
  color: var(--ink);
  font-weight: 700;
  line-height: 1.15;
}

.theme span {
  color: var(--muted);
  font-variant-numeric: tabular-nums;
  white-space: nowrap;
}

.settings {
  display: grid;
  gap: 10px;
}

.settings label:not(.check) {
  display: grid;
  gap: 6px;
  color: var(--muted);
  font-size: 13px;
  font-weight: 700;
}

input[type="number"] {
  width: 100%;
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 10px;
}

.check {
  display: flex;
  align-items: center;
  gap: 8px;
  color: var(--muted);
  font-size: 13px;
  font-weight: 700;
}

.workspace {
  min-width: 0;
  display: grid;
  gap: 14px;
}

.sessionbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 14px;
  padding: 16px 18px;
}

.question-card {
  min-height: 440px;
  padding: clamp(18px, 3vw, 28px);
}

.question-card.empty {
  display: grid;
  place-items: center;
}

.empty-state {
  max-width: 560px;
  text-align: center;
  display: grid;
  gap: 10px;
  color: var(--muted);
}

.empty-state h2 {
  color: var(--ink);
  font-size: 24px;
}

.meta {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 16px;
}

.pill {
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: 6px 10px;
  color: var(--muted);
  background: #fbfaf7;
  font-size: 12px;
  font-weight: 800;
}

.question-text {
  font-size: 20px;
  line-height: 1.48;
  margin-bottom: 20px;
}

.figures {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 12px;
  margin: -4px 0 22px;
}

.figures figure {
  display: grid;
  place-items: center;
  max-width: min(100%, 420px);
  margin: 0;
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 10px;
  background: white;
}

.figures img {
  display: block;
  max-width: 100%;
  max-height: 300px;
  width: auto;
  height: auto;
  object-fit: contain;
}

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

.option {
  display: grid;
  grid-template-columns: 34px 1fr;
  gap: 12px;
  align-items: start;
  width: 100%;
  min-height: 58px;
  padding: 12px;
  text-align: left;
}

.option .letter {
  display: grid;
  place-items: center;
  width: 34px;
  height: 34px;
  border-radius: 50%;
  background: #e8f1f0;
  color: var(--accent);
  font-weight: 900;
}

.option.selected {
  border-color: var(--accent);
  background: #edf8f7;
}

.option.correct {
  border-color: rgba(29, 122, 80, 0.55);
  background: rgba(29, 122, 80, 0.1);
}

.option.incorrect {
  border-color: rgba(179, 58, 50, 0.5);
  background: rgba(179, 58, 50, 0.08);
}

.explanation {
  display: grid;
  gap: 12px;
  margin-top: 18px;
  border: 1px solid rgba(16, 107, 114, 0.24);
  border-radius: 8px;
  padding: 14px;
  background: rgba(237, 248, 247, 0.72);
}

.explanation h3 {
  margin: 0 0 6px;
  font-size: 15px;
}

.explanation p {
  color: var(--muted);
  line-height: 1.35;
}

.explanation p + p {
  margin-top: 6px;
}

.explanation strong {
  color: var(--ink);
}

.explanation a {
  color: var(--accent);
  font-weight: 800;
  text-decoration: none;
}

.reference-box {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
  margin-top: 10px;
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 9px 10px;
  background: rgba(255, 255, 255, 0.72);
}

.reference-box span {
  color: var(--muted);
  font-size: 13px;
  font-weight: 800;
}

.reference-box a {
  border: 1px solid rgba(16, 107, 114, 0.24);
  border-radius: 8px;
  padding: 6px 10px;
  background: #fff;
  font-size: 13px;
}

.explanation label {
  display: grid;
  gap: 6px;
  color: var(--muted);
  font-size: 13px;
  font-weight: 800;
}

.explanation textarea {
  margin: 0;
  background: #fff;
}

.explanation button {
  justify-self: start;
}

.answer-tools {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 18px;
}

.navrow {
  display: grid;
  grid-template-columns: 1fr 1fr 1fr;
  gap: 10px;
}

.score-box {
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 12px;
  background: #fbfaf7;
  color: var(--muted);
  line-height: 1.35;
}

.score-box strong {
  color: var(--ink);
}

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

.question-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(38px, 1fr));
  gap: 7px;
}

.question-grid button {
  min-height: 36px;
  padding: 0;
  font-size: 12px;
  font-weight: 800;
}

.question-grid .answered {
  border-color: var(--accent);
  color: var(--accent);
}

.question-grid .current {
  background: var(--accent-2);
  border-color: var(--accent-2);
  color: #fff;
}

.history,
.importer {
  color: var(--muted);
  font-size: 13px;
}

.history summary,
.importer summary {
  cursor: pointer;
  color: var(--ink);
  font-weight: 800;
}

.history-list {
  display: grid;
  gap: 8px;
  margin-top: 10px;
}

.history-item {
  display: grid;
  gap: 10px;
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 10px;
  background: #fbfaf7;
}

.history-item div:first-child {
  display: grid;
  gap: 2px;
}

.history-item strong {
  color: var(--ink);
}

.history-item small,
.history-item span {
  color: var(--muted);
}

.history-actions {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 8px;
}

.history-actions button {
  min-height: 34px;
  padding: 0 8px;
  font-size: 12px;
  font-weight: 800;
}

textarea {
  width: 100%;
  margin: 10px 0;
  resize: vertical;
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 10px;
}

@media (max-width: 1050px) {
  .layout {
    grid-template-columns: 1fr;
  }

  .panel {
    width: 100%;
  }

  .theme-list {
    max-height: none;
  }
}

@media (max-width: 640px) {
  .topbar,
  .sessionbar {
    align-items: start;
    flex-direction: column;
  }

  h1 {
    font-size: 29px;
  }

  .question-text {
    font-size: 18px;
  }

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