:root {
  --bg-dark: #0d0f1a;
  --bg-panel: #1a1d33;
  --text: #e0e8ff;
  --muted: #a0a8c8;
  --accent-blue: #6fa8ff;
  --accent-pink: #ff7ac2;
  --accent-green: #6fe3a2;
  --accent-red: #ff6f6f;
  --accent-yellow: #ffd86b;
  --accent-orange: #ff9b5a;
  --shadow: 0 8px 30px rgba(0, 0, 0, 0.5);
}

* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  background: radial-gradient(circle at top, #1e2245, var(--bg-dark) 70%);
  color: var(--text);
  font-family: "Lexend", sans-serif;
  height: 100%;
  overflow: hidden;
}

/* Header */
.app-header {
  padding: 12px 20px;
  border-bottom: 1px solid #303560;
  background: rgba(26, 29, 51, 0.8);
  backdrop-filter: blur(10px);
}

.title-wrap {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  flex-wrap: wrap;
}

.brand {
  display: flex;
  align-items: flex-end;
  gap: 10px;
  flex-wrap: wrap;
}

.limit-badge {
  font-size: 32px;
  font-weight: 900;
  color: var(--accent-blue);
  line-height: 1;
  text-shadow: 0 0 12px var(--accent-blue);
}

.game-title {
  font-size: 32px;
  font-weight: 900;
  background: linear-gradient(45deg, var(--accent-blue), var(--accent-pink));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  line-height: 1;
}

.score-display {
  display: flex;
  align-items: baseline;
  gap: 6px;
  font-family: "Space Mono", monospace;
}

.score-label {
  font-size: 14px;
  color: var(--muted);
}

.score-value {
  font-size: 32px;
  font-weight: 900;
  color: var(--accent-green);
  text-shadow: 0 0 12px var(--accent-green);
}

.score-max {
  font-size: 20px;
  color: var(--muted);
  font-weight: 700;
}

.subtitle {
  color: var(--muted);
  font-size: 12px;
  margin-top: 4px;
}

/* Layout */
.layout {
  padding: 16px;
  height: calc(100vh - 95px);
}

.main-panel {
  width: 100%;
  height: 100%;
  background: #000;
  border-radius: 16px;
  box-shadow: var(--shadow);
  overflow: hidden;
  border: 1px solid #303560;
  position: relative;
}

#mainCanvas {
  width: 100%;
  height: 100%;
  display: block;
  position: absolute;
  top: 0;
  left: 0;
}

/* Question Content (in main panel) */
.question-content {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 24px;
  align-items: start;
  padding: 40px;
  background: radial-gradient(circle at top, #1e2245, #0d0f1a 70%);
  z-index: 2;
  overflow-y: auto;
}

.question-content.hidden {
  display: none;
}

.question-section {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 16px;
  max-width: 600px;
  width: 100%;
  justify-self: center;
}

/* Overlays */
.overlay {
  position: fixed;
  inset: 0;
  display: none;
  place-items: center;
  background: rgba(13, 15, 26, 0.85);
  backdrop-filter: blur(12px);
  z-index: 100;
  overflow-y: auto;
  padding: 20px;
}

.overlay.visible {
  display: grid;
}

.card {
  background: var(--bg-panel);
  border-radius: 16px;
  padding: 28px;
  width: min(680px, 94vw);
  text-align: center;
  box-shadow: var(--shadow);
  border: 1px solid #303560;
  max-height: 90vh;
  overflow-y: auto;
}

.card::-webkit-scrollbar {
  width: 8px;
}

.card::-webkit-scrollbar-track {
  background: var(--bg-dark);
  border-radius: 4px;
}

.card::-webkit-scrollbar-thumb {
  background: #303560;
  border-radius: 4px;
}

.card h2 {
  margin: 0 0 20px 0;
  background: linear-gradient(45deg, var(--accent-blue), var(--accent-pink));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  font-size: 28px;
}

/* Background Cards */
.background-scene {
  margin: 20px 0;
}

.scene-canvas {
  width: 100%;
  height: 250px;
  border-radius: 12px;
  border: 1px solid #303560;
  background: linear-gradient(to bottom, #1a1d33, #0d0f1a);
  display: block;
  margin-bottom: 16px;
}

.scene-text {
  text-align: left;
  line-height: 1.7;
}

.scene-title {
  font-size: 22px;
  font-weight: 700;
  color: var(--accent-yellow);
  margin-bottom: 12px;
  text-align: center;
}

.scene-description {
  font-size: 15px;
  color: var(--text);
}

/* Formulas Box in Background 2 */
.formulas-box {
  background: rgba(111, 168, 255, 0.1);
  border: 2px solid var(--accent-blue);
  border-radius: 12px;
  padding: 20px;
  margin: 20px 0;
}

.formulas-box-title {
  font-size: 18px;
  font-weight: 700;
  color: var(--accent-blue);
  margin: 0 0 16px 0;
  text-align: center;
}

.formulas-compact {
  display: grid;
  gap: 10px;
  font-family: "Space Mono", monospace;
}

.formula-row {
  font-size: 14px;
  color: var(--text);
  padding: 8px 12px;
  background: rgba(26, 29, 51, 0.5);
  border-radius: 6px;
  text-align: center;
}

.formula-row strong {
  color: var(--accent-green);
}

.formula-row .or {
  color: var(--muted);
  font-size: 12px;
  margin: 0 4px;
}

/* Formula Reference Panel */
.formula-reference-panel {
  background: rgba(26, 29, 51, 0.8);
  border: 2px solid var(--accent-blue);
  border-radius: 12px;
  padding: 20px;
  width: 280px;
  position: sticky;
  top: 20px;
  max-height: calc(100vh - 180px);
  overflow-y: auto;
}

.reference-title {
  font-size: 18px;
  font-weight: 700;
  color: var(--accent-blue);
  margin: 0 0 16px 0;
  text-align: center;
}

.reference-section {
  margin-bottom: 20px;
}

.reference-section:last-child {
  margin-bottom: 0;
}

.reference-subtitle {
  font-size: 14px;
  font-weight: 700;
  color: var(--accent-pink);
  margin: 0 0 10px 0;
}

.reference-formulas {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.ref-formula {
  font-family: "Space Mono", monospace;
  font-size: 12px;
  color: var(--text);
  padding: 6px 8px;
  background: rgba(111, 168, 255, 0.1);
  border-radius: 4px;
  border-left: 3px solid var(--accent-blue);
}

.ref-formula strong {
  color: var(--accent-green);
}

.reference-tips {
  margin: 0;
  padding-left: 20px;
  font-size: 12px;
  color: var(--muted);
  line-height: 1.6;
}

.reference-tips li {
  margin-bottom: 6px;
}

@media (max-width: 1024px) {
  .question-content {
    grid-template-columns: 1fr;
  }

  .formula-reference-panel {
    width: 100%;
    max-width: 600px;
    position: static;
    margin: 0 auto;
  }
}

/* Graph Cards */
.graph-card {
  width: min(800px, 94vw);
}

.formula-display {
  background: rgba(111, 168, 255, 0.1);
  border: 2px solid var(--accent-blue);
  border-radius: 12px;
  padding: 16px;
  margin: 16px 0;
  font-family: "Space Mono", monospace;
  font-size: 18px;
  font-weight: 700;
  color: var(--accent-blue);
}

.formula-display .or {
  color: var(--muted);
  font-size: 14px;
  margin: 0 8px;
}

.graph-canvas {
  width: 100%;
  height: 320px;
  border-radius: 12px;
  border: 1px solid #303560;
  background: #000;
  display: block;
  margin: 20px 0;
}

.graph-explanation {
  text-align: left;
  background: rgba(111, 227, 162, 0.1);
  border-left: 3px solid var(--accent-green);
  padding: 16px;
  border-radius: 8px;
  line-height: 1.7;
  font-size: 14px;
  margin-top: 16px;
}

.graph-explanation strong {
  color: var(--accent-green);
}

/* Instructions */
.instructions-grid {
  display: grid;
  gap: 12px;
  margin: 20px 0;
  text-align: left;
}

.instruction-item {
  display: flex;
  gap: 16px;
  align-items: flex-start;
  background: rgba(111, 168, 255, 0.05);
  padding: 16px;
  border-radius: 10px;
  border: 1px solid #303560;
}

.instruction-icon {
  font-size: 28px;
  flex-shrink: 0;
}

.instruction-item div {
  line-height: 1.6;
  font-size: 14px;
}

.instruction-item strong {
  color: var(--accent-blue);
}

/* Setup Form */
.card.setup input {
  width: 100%;
  padding: 12px;
  margin-top: 6px;
  border-radius: 10px;
  border: 1px solid #4a4f80;
  background: var(--bg-dark);
  color: var(--text);
  font-family: "Space Mono";
  font-size: 16px;
  transition: all 0.2s;
}

.card.setup input:focus {
  outline: none;
  border-color: var(--accent-blue);
  box-shadow: 0 0 12px rgba(111, 168, 255, 0.3);
}

.card.setup label {
  display: block;
  margin-bottom: 20px;
  text-align: left;
  font-weight: 600;
  font-size: 15px;
}

/* Avatar Selector */
.avatar-selector {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
  margin-top: 12px;
  padding: 16px;
  background: var(--bg-dark);
  border-radius: 12px;
  border: 1px solid #4a4f80;
}

.avatar-option {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  padding: 20px;
  border-radius: 12px;
  border: 3px solid transparent;
  background: #262a47;
  cursor: pointer;
  transition: all 0.3s;
}

.avatar-option:hover {
  background: #2e3351;
  border-color: var(--accent-blue);
  transform: scale(1.05);
}

.avatar-option.selected {
  background: linear-gradient(45deg, var(--accent-blue), var(--accent-pink));
  border-color: transparent;
  box-shadow: 0 0 20px rgba(111, 168, 255, 0.6);
}

.avatar-option img {
  width: 120px;
  height: 120px;
  display: block;
}

.avatar-option span {
  font-size: 16px;
  color: var(--text);
  font-weight: 700;
  text-align: center;
}

.avatar-option.selected span {
  color: white;
  text-shadow: 0 2px 4px rgba(0, 0, 0, 0.5);
}

/* Question Card */
.question-card {
  width: min(600px, 94vw);
}

.question-content .question-header,
.question-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 20px;
  padding: 12px 16px;
  background: rgba(111, 168, 255, 0.1);
  border-radius: 10px;
  font-family: "Space Mono", monospace;
  width: 100%;
  max-width: 600px;
}

.question-content .question-text,
.question-text {
  font-size: 26px;
  font-weight: 700;
  color: var(--text);
  margin: 20px 0;
  font-family: "Space Mono", monospace;
  text-align: center;
}

.question-content form,
.question-content .feedback {
  width: 100%;
  max-width: 600px;
}

.question-section {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 16px;
  max-width: 600px;
  width: 100%;
}

.question-content .airplane-window {
  width: 100%;
  max-width: 600px;
  margin: 20px 0;
}

.question-number-group {
  display: flex;
  align-items: center;
  gap: 8px;
}

.question-number {
  font-size: 16px;
  font-weight: 700;
  color: var(--accent-blue);
}

.destination-indicator {
  font-size: 14px;
  font-weight: 600;
  color: #ffd700;
  text-shadow: 0 0 8px rgba(255, 215, 0, 0.6);
  margin-left: 4px;
}

.help-icon-btn {
  appearance: none;
  border: 2px solid var(--accent-blue);
  background: rgba(111, 168, 255, 0.2);
  color: var(--accent-blue);
  border-radius: 50%;
  width: 24px;
  height: 24px;
  font-weight: 900;
  font-size: 14px;
  line-height: 1;
  text-align: center;
  cursor: pointer;
  transition: all 0.2s;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 0;
}

.help-icon-btn:hover {
  transform: scale(1.1);
  background: var(--accent-blue);
  color: #fff;
  box-shadow: 0 0 12px rgba(111, 168, 255, 0.6);
}

.question-timer {
  font-size: 18px;
  font-weight: 700;
  color: var(--accent-yellow);
}

.airplane-window {
  margin: 20px 0;
  width: 100%;
}

.window-canvas {
  width: 100%;
  max-width: 400px;
  height: 200px;
  border-radius: 50%;
  border: 8px solid #4a4f80;
  background: linear-gradient(to bottom, #87ceeb, #f0f8ff);
  display: block;
  box-shadow: inset 0 4px 20px rgba(0, 0, 0, 0.3);
  margin: 0 auto;
}

.question-text {
  font-size: 26px;
  font-weight: 700;
  color: var(--text);
  margin: 20px 0;
  font-family: "Space Mono", monospace;
}

.answer-input-group {
  display: flex;
  align-items: center;
  gap: 12px;
  margin: 20px 0;
  background: var(--bg-dark);
  padding: 6px;
  border-radius: 12px;
  border: 2px solid #4a4f80;
}

.answer-input {
  flex: 1;
  padding: 14px;
  border: none;
  background: transparent;
  color: var(--text);
  font-family: "Space Mono";
  font-size: 24px;
  font-weight: 700;
  text-align: center;
}

.answer-input:focus {
  outline: none;
}

.answer-unit {
  font-size: 24px;
  font-weight: 700;
  color: var(--accent-blue);
  font-family: "Space Mono";
  padding-right: 12px;
}

.feedback {
  margin-top: 16px;
  padding: 12px;
  border-radius: 8px;
  font-size: 16px;
  font-weight: 600;
  min-height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.feedback.correct {
  background: rgba(111, 227, 162, 0.2);
  border: 2px solid var(--accent-green);
  color: var(--accent-green);
}

.feedback.incorrect {
  background: rgba(255, 111, 111, 0.2);
  border: 2px solid var(--accent-red);
  color: var(--accent-red);
}

/* Result Card */
.result-card {
  width: min(700px, 94vw);
}

.final-score-display {
  display: flex;
  justify-content: center;
  margin: 24px 0;
}

.final-score-display .score-item {
  display: flex;
  align-items: baseline;
  gap: 8px;
}

.final-score-display .label {
  font-size: 14px;
  color: var(--muted);
}

.final-score-display .value {
  font-size: 56px;
  font-weight: 900;
  color: var(--accent-green);
  font-family: "Space Mono";
  text-shadow: 0 0 20px var(--accent-green);
}

.final-score-display .max {
  font-size: 28px;
  color: var(--muted);
  font-family: "Space Mono";
}

.destination-info {
  margin: 24px 0;
}

.destination-info h3 {
  font-size: 28px;
  font-weight: 700;
  background: linear-gradient(
    45deg,
    var(--accent-orange),
    var(--accent-yellow)
  );
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin: 0 0 8px 0;
}

.destination-temp {
  font-size: 18px;
  color: var(--accent-blue);
  font-family: "Space Mono";
  font-weight: 700;
}

.destination-scene {
  margin: 20px 0;
}

.destination-canvas {
  width: 100%;
  height: 300px;
  border-radius: 12px;
  border: 1px solid #303560;
  background: linear-gradient(to bottom, #87ceeb, #f0e68c);
  display: block;
  box-shadow: var(--shadow);
}

.result-message {
  font-size: 15px;
  line-height: 1.7;
  color: var(--text);
  margin: 20px 0;
}

/* Countdown */
.countdown {
  font-family: "Space Mono";
  color: var(--accent-pink);
  margin: 20px 0 0 0;
  font-size: 15px;
  font-weight: 700;
}

.countdown kbd {
  background: rgba(111, 168, 255, 0.2);
  padding: 4px 8px;
  border-radius: 4px;
  border: 1px solid var(--accent-blue);
  font-family: "Space Mono";
  color: var(--accent-blue);
}

/* Buttons */
button.primary {
  width: 100%;
  background: linear-gradient(45deg, var(--accent-blue), var(--accent-pink));
  border: none;
  color: #fff;
  padding: 14px;
  border-radius: 12px;
  font-weight: 700;
  font-size: 16px;
  cursor: pointer;
  text-shadow: 0 1px 3px rgba(0, 0, 0, 0.5);
  transition: all 0.3s;
  box-shadow: 0 4px 15px rgba(111, 168, 255, 0.3);
}

button.primary:hover {
  transform: scale(1.02);
  box-shadow: 0 6px 25px rgba(111, 168, 255, 0.6);
}

button.primary:active {
  transform: scale(0.98);
}

/* Formula Help Modal */
.formula-help-card {
  width: min(800px, 94vw);
  max-height: 85vh;
  overflow-y: auto;
}

.background-content {
  text-align: left;
  margin: 24px 0;
  line-height: 1.7;
}

.background-section {
  margin-bottom: 32px;
}

.background-section:last-child {
  margin-bottom: 0;
}

.background-section h3 {
  font-size: 18px;
  font-weight: 700;
  color: var(--accent-pink);
  margin: 0 0 16px 0;
}

.background-section p {
  font-size: 15px;
  color: var(--text);
  margin: 0 0 12px 0;
}

.formula-highlight {
  font-family: "Space Mono", monospace;
  font-size: 16px;
  font-weight: 700;
  color: var(--accent-green);
  background: rgba(111, 168, 255, 0.1);
  padding: 12px 20px;
  border-radius: 8px;
  border-left: 4px solid var(--accent-blue);
  margin: 16px 0;
  text-align: center;
}

.formulas-list {
  display: flex;
  flex-direction: column;
  gap: 16px;
  margin: 24px 0;
  text-align: left;
}

.formula-item {
  background: rgba(111, 168, 255, 0.05);
  padding: 16px;
  border-radius: 10px;
  border: 1px solid #303560;
}

.formula-title {
  font-size: 16px;
  font-weight: 700;
  color: var(--accent-blue);
  margin-bottom: 8px;
}

.formula-equation {
  font-family: "Space Mono", monospace;
  font-size: 15px;
  color: var(--text);
  line-height: 1.6;
}

.formula-equation .or {
  color: var(--muted);
  font-size: 13px;
  margin: 0 6px;
}

.formula-note {
  display: block;
  font-size: 12px;
  color: var(--muted);
  font-family: "Lexend", sans-serif;
  margin-top: 4px;
}

/* Formulas Reference (Hidden by default) */
.formulas-reference {
  display: none;
}

/* Responsive */
@media (max-width: 768px) {
  .game-title {
    font-size: 26px;
  }

  .limit-badge {
    font-size: 26px;
  }

  .score-value {
    font-size: 26px;
  }

  .card h2 {
    font-size: 24px;
  }

  .question-text {
    font-size: 22px;
  }

  .answer-input,
  .answer-unit {
    font-size: 20px;
  }

  .avatar-option img {
    width: 100px;
    height: 100px;
  }

  .avatar-selector {
    grid-template-columns: repeat(2, 1fr);
  }

  .scene-canvas {
    height: 200px;
  }

  .graph-canvas {
    height: 260px;
  }
}

@media (max-width: 480px) {
  .title-wrap {
    flex-direction: column;
    align-items: flex-start;
  }

  .game-title {
    font-size: 22px;
  }

  .limit-badge {
    font-size: 22px;
  }

  .card {
    padding: 20px;
  }
}

/* Formula Reference Panel */
.formula-reference-panel {
  background: rgba(26, 29, 51, 0.9);
  border: 2px solid var(--accent-blue);
  border-radius: 12px;
  padding: 24px;
  width: 340px;
  position: sticky;
  top: 20px;
  max-height: calc(100vh - 180px);
  overflow-y: auto;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.4);
}

.reference-title {
  font-size: 22px;
  font-weight: 700;
  color: var(--accent-blue);
  margin: 0 0 20px 0;
  text-align: center;
}

.reference-section {
  margin-bottom: 24px;
}

.reference-section:last-child {
  margin-bottom: 0;
}

.reference-subtitle {
  font-size: 16px;
  font-weight: 700;
  color: var(--accent-pink);
  margin: 0 0 12px 0;
}

.reference-formulas {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.ref-formula {
  font-family: "Space Mono", monospace;
  font-size: 14px;
  color: var(--text);
  padding: 10px 12px;
  background: rgba(111, 168, 255, 0.1);
  border-radius: 6px;
  border-left: 4px solid var(--accent-blue);
}

.ref-formula strong {
  color: var(--accent-green);
}

.reference-tips {
  margin: 0;
  padding-left: 22px;
  font-size: 14px;
  color: var(--muted);
  line-height: 1.7;
}

.reference-tips li {
  margin-bottom: 8px;
}

@media (max-width: 1100px) {
  .question-content {
    grid-template-columns: 1fr;
    justify-items: center;
  }

  .formula-reference-panel {
    width: 100%;
    max-width: 600px;
    position: static;
    margin: 0 auto;
  }

  .avatar-option img {
    width: 80px;
    height: 80px;
  }

  .final-score-display .value {
    font-size: 42px;
  }
}