:root {
  color-scheme: light;
  --ink: #18212f;
  --muted: #5f6877;
  --paper: #f5f1e8;
  --panel: #fffdf7;
  --line: #d8cfbf;
  --accent: #246b63;
  --accent-strong: #164d47;
  --warn: #9b3d2e;
  --gold: #b6842c;
  --shadow: 0 18px 60px rgba(24, 33, 47, 0.14);
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  font-family:
    system-ui,
    -apple-system,
    BlinkMacSystemFont,
    "Segoe UI",
    sans-serif;
  background:
    linear-gradient(rgba(245, 241, 232, 0.9), rgba(245, 241, 232, 0.96)),
    repeating-linear-gradient(90deg, rgba(36, 107, 99, 0.08) 0 1px, transparent 1px 84px),
    var(--paper);
  color: var(--ink);
}

button {
  font: inherit;
}

.app-shell {
  width: min(1120px, calc(100% - 32px));
  margin: 0 auto;
  padding: 28px 0 40px;
  display: grid;
  gap: 18px;
}

.topbar {
  display: flex;
  justify-content: space-between;
  align-items: end;
  gap: 24px;
  padding: 10px 2px;
}

.topbar-actions {
  display: grid;
  justify-items: end;
  gap: 10px;
}

h1,
h2,
p {
  margin: 0;
}

h1 {
  font-family: Georgia, "Times New Roman", serif;
  font-size: clamp(2.1rem, 6vw, 4.8rem);
  font-weight: 700;
  line-height: 0.95;
}

.topbar p {
  margin-top: 10px;
  color: var(--muted);
}

.stats {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
  justify-content: flex-end;
}

.set-picker,
.language-picker {
  display: grid;
  gap: 6px;
  margin: 0;
  padding: 0;
  border: 0;
  color: var(--muted);
  font-size: 0.9rem;
}

.set-picker legend,
.language-picker legend {
  padding: 0;
  margin-bottom: 6px;
}

.set-options,
.language-options {
  display: grid;
  gap: 6px;
}

.set-option,
.language-option,
.mode-option {
  display: flex;
  align-items: center;
  gap: 8px;
  min-height: 38px;
  border: 1px solid var(--line);
  border-radius: 6px;
  background: rgba(255, 253, 247, 0.95);
  color: var(--ink);
  padding: 0 12px;
  cursor: pointer;
}

.set-option:has(input:checked),
.language-option:has(input:checked),
.mode-option:has(input:checked) {
  border-color: var(--accent);
  box-shadow: inset 0 0 0 1px rgba(36, 107, 99, 0.3);
}

.set-option input,
.language-option input,
.mode-option input {
  margin: 0;
}

.mode-option {
  width: 100%;
  color: var(--ink);
}

.mode-option:has(input:disabled) {
  opacity: 0.72;
  cursor: default;
}

.language-options {
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.stats > span,
.challenge-meta span {
  border: 1px solid var(--line);
  background: rgba(255, 253, 247, 0.75);
  padding: 8px 12px;
  border-radius: 999px;
  color: var(--muted);
  white-space: nowrap;
}

.stats strong {
  color: var(--accent-strong);
}

.challenge-panel,
.timeline-panel,
.result-panel {
  background: rgba(255, 253, 247, 0.9);
  border: 1px solid var(--line);
  box-shadow: var(--shadow);
}

.challenge-panel {
  position: sticky;
  top: 12px;
  z-index: 10;
  padding: clamp(20px, 4vw, 34px);
  backdrop-filter: blur(14px);
}

.challenge-meta {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  flex-wrap: wrap;
  margin-bottom: 18px;
}

.challenge-panel h2 {
  font-size: clamp(1.45rem, 3vw, 2.35rem);
  line-height: 1.18;
}

.challenge-panel p {
  margin-top: 12px;
  color: var(--muted);
  font-size: 1.05rem;
  line-height: 1.65;
}

.challenge-panel.draggable-card {
  cursor: grab;
}

.challenge-panel.is-dragging {
  cursor: grabbing;
  opacity: 0.72;
}

.timeline-panel {
  padding: 18px;
}

.timeline-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 10px;
}

.timeline-header h2 {
  font-size: 1rem;
  text-transform: uppercase;
  color: var(--muted);
}

#start-button,
#restart-button,
#next-button {
  border: 1px solid var(--accent);
  background: var(--accent);
  color: white;
  border-radius: 6px;
  min-height: 40px;
  padding: 0 16px;
  cursor: pointer;
}

#restart-button {
  background: transparent;
  color: var(--accent-strong);
}

#start-button {
  width: 100%;
}

.share-button {
  width: min(100%, 680px);
  min-height: 42px;
  margin: 0 auto 12px;
  display: block;
  border: 1px solid var(--ink);
  background: var(--ink);
  color: white;
  border-radius: 6px;
  padding: 0 16px;
  cursor: pointer;
}

.share-button[hidden] {
  display: none;
}

.false-zone {
  width: min(100%, 680px);
  margin: 0 auto 12px;
  display: grid;
  gap: 10px;
}

.false-zone[hidden] {
  display: none;
}

.false-drop-button {
  min-height: 72px;
  border: 1px dashed var(--warn);
  background: rgba(155, 61, 46, 0.08);
  color: var(--warn);
  border-radius: 6px;
  padding: 18px 16px;
  cursor: pointer;
  font-weight: 700;
}

.false-drop-button:hover,
.false-drop-button:focus-visible,
.false-drop-button.drag-over {
  background: rgba(155, 61, 46, 0.16);
}

.false-drop-button.drag-over,
.false-drop-button.correct-position {
  border-style: solid;
  box-shadow: inset 0 0 0 2px rgba(155, 61, 46, 0.22);
}

.false-drop-button:disabled {
  cursor: default;
  opacity: 0.68;
}

.false-list {
  display: grid;
  gap: 8px;
}

.false-list h3,
.false-empty {
  margin: 0;
  color: var(--muted);
  font-size: 0.9rem;
}

.timeline {
  list-style: none;
  margin: 0 auto;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 12px;
  width: min(100%, 680px);
}

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

.insert-button {
  min-height: 64px;
  border: 1px dashed var(--accent);
  background: rgba(36, 107, 99, 0.08);
  color: var(--accent-strong);
  border-radius: 6px;
  padding: 18px 16px;
  cursor: pointer;
}

.insert-button:hover,
.insert-button:focus-visible,
.insert-button.drag-over {
  background: rgba(36, 107, 99, 0.16);
}

.insert-button.drag-over {
  border-style: solid;
  box-shadow: inset 0 0 0 2px rgba(36, 107, 99, 0.24);
}

.card {
  min-height: 168px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  gap: 16px;
  border: 1px solid var(--line);
  background: var(--panel);
  padding: 16px;
  border-radius: 8px;
}

.card.correct-position {
  border-color: var(--gold);
  box-shadow: inset 0 0 0 2px rgba(182, 132, 44, 0.2);
}

.card-title {
  font-weight: 700;
  line-height: 1.35;
}

.card-statement {
  color: var(--muted);
  font-size: 0.94rem;
  line-height: 1.5;
}

.card-explanation {
  margin-top: 12px;
  padding-top: 12px;
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-size: 0.9rem;
  line-height: 1.5;
}

.card-year {
  color: var(--accent-strong);
  font-weight: 700;
}

.result-panel {
  position: sticky;
  bottom: 18px;
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 8px 18px;
  align-items: center;
  padding: 18px;
  border-left: 5px solid var(--accent);
}

.result-panel[hidden] {
  display: none;
}

.result-panel.error {
  border-left-color: var(--warn);
}

.result-panel.error #result-icon {
  color: #1167c4;
}

.result-panel h2 {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 1.1rem;
}

#result-icon {
  color: var(--accent);
  font-size: 4rem;
  font-weight: 800;
  line-height: 1;
}

.result-panel p {
  color: var(--muted);
  line-height: 1.55;
}

.confetti-layer {
  position: fixed;
  inset: 0;
  z-index: 100;
  pointer-events: none;
  overflow: hidden;
}

.confetti-piece {
  position: absolute;
  left: 50%;
  top: 38%;
  width: 10px;
  height: 18px;
  border-radius: 2px;
  opacity: 0;
  animation: confetti-burst 2.4s cubic-bezier(0.16, 0.9, 0.22, 1) var(--delay) forwards;
}

@keyframes confetti-burst {
  0% {
    opacity: 1;
    transform: translate(-50%, -50%) scale(0.7) rotate(0deg);
  }

  45% {
    opacity: 1;
  }

  100% {
    opacity: 0;
    transform: translate(calc(-50% + var(--x)), calc(-50% + var(--y) + 260px)) scale(1) rotate(var(--rotation));
  }
}

@media (max-width: 720px) {
  .app-shell {
    width: min(100% - 20px, 1120px);
    padding-top: 16px;
  }

  .challenge-panel {
    top: 8px;
  }

  .topbar {
    display: grid;
    align-items: start;
  }

  .stats {
    justify-content: flex-start;
  }

  .topbar-actions {
    justify-items: start;
  }

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

  .result-panel {
    grid-template-columns: 1fr;
  }
}