:root {
  --bg: #fef6df;
  --bg-accent: #d8f4ff;
  --surface: rgba(255, 255, 255, 0.88);
  --surface-strong: #ffffff;
  --ink: #23415d;
  --ink-soft: #4e6a7f;
  --math: #ff8b5c;
  --math-dark: #db5e2d;
  --science: #39b68d;
  --science-dark: #1c8c69;
  --yellow: #ffd65b;
  --sky: #8bd4ff;
  --success: #30b45f;
  --shadow: 0 20px 60px rgba(35, 65, 93, 0.16);
  --radius-xl: 32px;
  --radius-lg: 24px;
  --radius-md: 18px;
  --radius-sm: 14px;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  font-family: "Trebuchet MS", "Arial Rounded MT Bold", "Segoe UI", sans-serif;
  color: var(--ink);
  background:
    radial-gradient(circle at top left, rgba(255, 214, 91, 0.65), transparent 28%),
    radial-gradient(circle at top right, rgba(139, 212, 255, 0.55), transparent 24%),
    linear-gradient(180deg, var(--bg) 0%, #fff7ec 55%, #f8fbff 100%);
}

img {
  display: block;
  max-width: 100%;
}

button {
  font: inherit;
}

.app-shell {
  width: min(1120px, calc(100% - 32px));
  margin: 0 auto;
  padding: 28px 0 48px;
}

.hero-banner {
  text-align: center;
  margin-bottom: 24px;
}

.eyebrow,
.section-label,
.subject-pill {
  text-transform: uppercase;
  letter-spacing: 0.08em;
  font-size: 0.88rem;
  font-weight: 800;
}

.hero-banner h1,
.screen-card h2,
.question-content h3 {
  margin: 0;
  line-height: 1.1;
}

.hero-banner h1 {
  font-size: clamp(2.3rem, 5vw, 4.4rem);
}

.hero-copy,
.section-copy,
.helper-text,
.result-summary,
.subject-note {
  color: var(--ink-soft);
}

.hero-copy {
  max-width: 650px;
  margin: 12px auto 0;
  font-size: 1.15rem;
}

.screen {
  display: none;
}

.screen.active {
  display: block;
}

.screen-card {
  position: relative;
  overflow: hidden;
  background: var(--surface);
  border: 1px solid rgba(255, 255, 255, 0.85);
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow);
  backdrop-filter: blur(14px);
}

.subject-card,
.status-card {
  padding: 32px;
}

.subject-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 20px;
  margin-top: 28px;
}

.package-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 16px;
  margin-top: 24px;
}

.subject-button {
  min-height: 280px;
  border: 0;
  border-radius: 28px;
  padding: 24px;
  text-align: left;
  cursor: pointer;
  transition: transform 180ms ease, box-shadow 180ms ease;
  color: #fff;
  box-shadow: inset 0 -6px 0 rgba(0, 0, 0, 0.08);
}

.subject-button:hover,
.subject-button:focus-visible,
.package-button:hover,
.package-button:focus-visible,
.option-button:hover,
.option-button:focus-visible,
.speak-button:hover,
.speak-button:focus-visible,
.primary-button:hover,
.primary-button:focus-visible,
.secondary-button:hover,
.secondary-button:focus-visible {
  transform: translateY(-3px);
}

.subject-button.math {
  background: linear-gradient(160deg, #ff9f73 0%, var(--math-dark) 100%);
}

.subject-button.science {
  background: linear-gradient(160deg, #56d6aa 0%, var(--science-dark) 100%);
}

.package-button {
  min-height: 120px;
  border: 0;
  border-radius: 22px;
  padding: 20px;
  text-align: left;
  cursor: pointer;
  background: #fff;
  box-shadow: 0 12px 26px rgba(35, 65, 93, 0.1);
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.package-name {
  display: block;
  font-size: 1.5rem;
  font-weight: 900;
  color: var(--ink);
}

.package-note {
  display: block;
  font-size: 1rem;
  color: var(--ink-soft);
}

.subject-art {
  width: 120px;
  height: 120px;
  display: grid;
  place-items: center;
  margin-bottom: 20px;
  background: rgba(255, 255, 255, 0.18);
  border-radius: 26px;
}

.subject-name {
  display: block;
  font-size: 2rem;
  font-weight: 900;
  margin-bottom: 8px;
}

.subject-note {
  display: block;
  font-size: 1.05rem;
  color: rgba(255, 255, 255, 0.88);
}

.quiz-card {
  position: relative;
  padding: 28px;
}

.quiz-topbar {
  display: flex;
  gap: 16px;
  justify-content: space-between;
  align-items: end;
  margin-bottom: 24px;
}

.subject-pill {
  display: inline-flex;
  margin-bottom: 8px;
  padding: 8px 12px;
  border-radius: 999px;
  background: rgba(139, 212, 255, 0.26);
}

.quiz-timer,
.result-duration {
  margin: 12px 0 0;
  font-size: 1rem;
  font-weight: 800;
  color: var(--ink);
}

.quiz-timer {
  position: fixed;
  top: 20px;
  right: 20px;
  z-index: 50;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 128px;
  padding: 10px 14px;
  border: 1px solid rgba(255, 255, 255, 0.88);
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.92);
  box-shadow: 0 12px 28px rgba(35, 65, 93, 0.16);
}

.quiz-timer-icon {
  margin-right: 8px;
  line-height: 1;
}

.progress-wrap {
  min-width: 220px;
  text-align: right;
}

.progress-track {
  height: 16px;
  border-radius: 999px;
  background: rgba(35, 65, 93, 0.1);
  overflow: hidden;
  margin-bottom: 8px;
}

.progress-bar {
  height: 100%;
  width: 5%;
  border-radius: inherit;
  background: linear-gradient(90deg, var(--yellow), var(--math));
  transition: width 220ms ease;
}

.quiz-intro {
  margin-bottom: 20px;
  padding-right: 150px;
}

.questions-list {
  display: grid;
  gap: 20px;
}

.question-card {
  display: grid;
  grid-template-columns: 1fr;
  gap: 18px;
  align-items: start;
  padding: 20px;
  border-radius: 28px;
  background: rgba(255, 255, 255, 0.72);
  box-shadow: 0 12px 30px rgba(35, 65, 93, 0.08);
}

.question-visual {
  min-height: 240px;
  width: min(100%, 420px);
  padding: 18px;
  margin: 0 auto;
  border-radius: 28px;
  background: linear-gradient(180deg, rgba(216, 244, 255, 0.75), rgba(255, 255, 255, 0.95));
}

.question-visual img {
  width: 100%;
  height: 100%;
  object-fit: contain;
}

.question-content {
  width: 100%;
}

.question-heading {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 14px;
}

.question-content h3 {
  margin-top: 10px;
  font-size: clamp(1.8rem, 4vw, 2.6rem);
  text-align: center;
}

.question-number {
  margin: 0;
  justify-self: start;
  padding: 8px 14px;
  border-radius: 999px;
  background: rgba(255, 214, 91, 0.28);
  font-size: 0.95rem;
  font-weight: 800;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--math-dark);
}

.options-list {
  display: grid;
  gap: 14px;
  margin-top: 22px;
}

.option-button,
.speak-button,
.primary-button,
.secondary-button {
  min-height: 64px;
  border-radius: 20px;
  padding: 14px 18px;
  border: 0;
  cursor: pointer;
  transition: transform 180ms ease, box-shadow 180ms ease, background 180ms ease;
}

.speak-button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 52px;
  min-height: 52px;
  padding: 0;
  background: linear-gradient(135deg, #8bd4ff, #56d6aa);
  color: #173353;
  box-shadow: 0 10px 24px rgba(35, 65, 93, 0.12);
}

.speak-button.is-speaking {
  background: linear-gradient(135deg, #ffd65b, #ff9f73);
  color: #5b2d16;
}

.speak-button-icon {
  position: relative;
  width: 30px;
  height: 30px;
  flex: 0 0 30px;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.82);
}

.speak-button-icon::before {
  content: "";
  position: absolute;
  top: 7px;
  left: 10px;
  width: 0;
  height: 0;
  border-top: 7px solid transparent;
  border-bottom: 7px solid transparent;
  border-left: 10px solid currentColor;
}

.speak-button.is-speaking .speak-button-icon::before {
  top: 7px;
  left: 8px;
  width: 4px;
  height: 14px;
  border: 0;
  background: currentColor;
  box-shadow: 8px 0 0 currentColor;
}

.option-button {
  display: flex;
  align-items: center;
  gap: 14px;
  width: 100%;
  background: var(--surface-strong);
  color: var(--ink);
  border: 3px solid transparent;
  box-shadow: 0 10px 24px rgba(35, 65, 93, 0.08);
  text-align: left;
  font-size: 1.25rem;
  font-weight: 700;
}

.option-content,
.answer-preview {
  display: flex;
  align-items: center;
  gap: 12px;
  flex-wrap: wrap;
}

.option-content {
  flex: 1;
}

.option-image,
.answer-preview-image {
  display: block;
  object-fit: contain;
  border-radius: 16px;
  background: rgba(139, 212, 255, 0.16);
}

.option-image {
  width: 88px;
  height: 88px;
  padding: 8px;
}

.answer-preview-image {
  width: 72px;
  height: 72px;
  padding: 6px;
}

.option-text,
.answer-preview-text {
  line-height: 1.35;
}

.option-badge {
  width: 46px;
  height: 46px;
  border-radius: 16px;
  display: grid;
  place-items: center;
  background: rgba(139, 212, 255, 0.22);
  font-size: 1.2rem;
  font-weight: 900;
}

.option-button.selected {
  border-color: var(--success);
  background: #f3fff6;
}

.action-row {
  margin-top: 26px;
  display: flex;
  gap: 18px;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
}

.quiz-action-buttons {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
  justify-content: flex-end;
}

.package-actions {
  margin-top: 24px;
}

.helper-text {
  font-size: 1.05rem;
  margin: 0;
}

.primary-button {
  min-width: 190px;
  color: #fff;
  font-weight: 900;
  background: linear-gradient(135deg, #ff9f73, #ff7f50);
  box-shadow: 0 14px 30px rgba(255, 127, 80, 0.28);
}

.primary-button[disabled] {
  opacity: 0.45;
  cursor: not-allowed;
  transform: none;
}

.secondary-button {
  min-width: 190px;
  font-weight: 900;
  color: var(--ink);
  background: #fff;
  box-shadow: 0 10px 24px rgba(35, 65, 93, 0.1);
}

.result-card {
  min-height: 520px;
  display: grid;
  place-items: center;
  padding: 28px;
  background:
    radial-gradient(circle at top left, rgba(255, 214, 91, 0.6), transparent 24%),
    radial-gradient(circle at top right, rgba(86, 214, 170, 0.42), transparent 22%),
    rgba(255, 255, 255, 0.9);
}

#confetti-canvas {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
}

.result-content {
  position: relative;
  text-align: center;
  z-index: 1;
}

.score-badge {
  display: inline-flex;
  align-items: baseline;
  gap: 8px;
  margin: 18px 0 12px;
  padding: 18px 26px;
  border-radius: 999px;
  background: #fff;
  box-shadow: 0 14px 32px rgba(35, 65, 93, 0.14);
}

#score-value {
  font-size: clamp(3rem, 7vw, 5rem);
  font-weight: 900;
  line-height: 1;
}

.score-suffix {
  font-size: 1.5rem;
  font-weight: 800;
}

.result-summary {
  max-width: 500px;
  margin: 0 auto 10px;
  font-size: 1.1rem;
}

.result-duration {
  margin-bottom: 24px;
}

.result-details {
  display: grid;
  gap: 14px;
  width: min(100%, 760px);
  margin: 0 auto 24px;
  text-align: left;
}

.result-item {
  padding: 18px 20px;
  border-radius: 22px;
  background: rgba(255, 255, 255, 0.9);
  box-shadow: 0 10px 24px rgba(35, 65, 93, 0.1);
  border: 3px solid transparent;
}

.result-item.is-correct {
  border-color: rgba(48, 180, 95, 0.4);
}

.result-item.is-wrong {
  border-color: rgba(255, 139, 92, 0.4);
}

.result-item-top {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  align-items: center;
  margin-bottom: 8px;
}

.result-item-number,
.result-question,
.result-answer {
  margin: 0;
}

.result-item-number {
  font-size: 0.95rem;
  font-weight: 800;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--ink-soft);
}

.result-badge {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 38px;
  padding: 8px 14px;
  border-radius: 999px;
  font-size: 0.95rem;
  font-weight: 900;
  background: #fff7ec;
  color: var(--ink);
}

.result-question {
  margin-bottom: 10px;
  font-size: 1.25rem;
  line-height: 1.35;
}

.result-answer {
  display: flex;
  flex-direction: column;
  gap: 10px;
  margin: 0;
  font-size: 1rem;
  line-height: 1.45;
}

.result-answer-card {
  margin-top: 12px;
  padding: 14px 16px;
  border-radius: 18px;
  background: #fff;
}

.result-answer-label {
  margin: 0;
  font-size: 0.95rem;
  font-weight: 800;
}

.correct-answer-card {
  background: #f3fff6;
}

.wrong-answer-card {
  background: #fff5ee;
}

.correct-text {
  color: var(--success);
}

.wrong-text {
  color: var(--math-dark);
}

.result-actions {
  display: flex;
  gap: 16px;
  justify-content: center;
  flex-wrap: wrap;
}

.status-card {
  text-align: center;
}

.floating-back-button {
  position: fixed;
  right: 20px;
  bottom: 20px;
  min-height: 56px;
  min-width: 170px;
  border: 0;
  border-radius: 999px;
  padding: 12px 18px;
  cursor: pointer;
  color: var(--ink);
  background: #ffffff;
  box-shadow: 0 14px 30px rgba(35, 65, 93, 0.22);
  font-size: 1rem;
  font-weight: 900;
  z-index: 50;
  transition: transform 180ms ease, box-shadow 180ms ease;
}

.floating-back-button:hover,
.floating-back-button:focus-visible {
  transform: translateY(-3px);
}

@media (max-width: 860px) {
  .subject-grid,
  .package-grid {
    grid-template-columns: 1fr;
  }

  .quiz-topbar,
  .action-row {
    align-items: start;
    flex-direction: column;
  }

  .quiz-intro {
    padding-right: 0;
  }

  .quiz-action-buttons {
    width: 100%;
    justify-content: stretch;
  }

  .floating-back-button {
    right: 14px;
    left: 14px;
    bottom: 14px;
    min-width: 0;
  }

  .progress-wrap {
    width: 100%;
    text-align: left;
  }

  .quiz-timer {
    top: 14px;
    right: 14px;
    min-width: 0;
  }

  .speak-button {
    width: 48px;
    min-height: 48px;
  }
}

@media (max-width: 560px) {
  .app-shell {
    width: min(100% - 20px, 1120px);
    padding-top: 18px;
  }

  .subject-card,
  .quiz-card,
  .result-card,
  .status-card {
    padding: 20px;
  }

  .subject-button {
    min-height: 220px;
  }

  .subject-name {
    font-size: 1.7rem;
  }

  .option-button,
  .speak-button,
  .primary-button,
  .secondary-button {
    min-height: 60px;
  }
}