:root {
  --bg: #0d1632;
  --bg-alt: #13214a;
  --panel: rgba(17, 28, 65, 0.8);
  --panel-strong: rgba(14, 22, 50, 0.96);
  --text: #f5f7ff;
  --muted: #bed0ff;
  --line: rgba(255, 255, 255, 0.12);
  --yellow: #ffd54f;
  --orange: #ff8a3d;
  --green: #3de69a;
  --blue: #50a8ff;
  --pink: #ff6bc7;
  --shadow: 0 24px 60px rgba(2, 7, 23, 0.45);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-height: 100vh;
  overflow-x: hidden;
  font-family: "Nunito", sans-serif;
  color: var(--text);
  background:
    radial-gradient(circle at top left, rgba(80, 168, 255, 0.18), transparent 28%),
    radial-gradient(circle at top right, rgba(255, 107, 199, 0.16), transparent 24%),
    linear-gradient(180deg, var(--bg) 0%, var(--bg-alt) 100%);
}

button,
a {
  font: inherit;
}

a {
  color: inherit;
  text-decoration: none;
}

button {
  border: 0;
  cursor: pointer;
}

.background-glow {
  position: fixed;
  width: 320px;
  height: 320px;
  border-radius: 50%;
  filter: blur(30px);
  opacity: 0.25;
  pointer-events: none;
}

.background-glow-left {
  top: 60px;
  left: -90px;
  background: var(--pink);
}

.background-glow-right {
  right: -110px;
  bottom: 110px;
  background: var(--blue);
}

.page-shell {
  position: relative;
  z-index: 1;
  width: min(1180px, calc(100% - 1.5rem));
  margin: 0 auto;
  padding: 1rem 0 2.5rem;
}

.hero,
.panel {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 28px;
  box-shadow: var(--shadow);
  backdrop-filter: blur(18px);
}

.hero {
  position: relative;
  overflow: hidden;
  padding: 1.25rem;
}

.hero::before,
.hero::after {
  content: "";
  position: absolute;
  border-radius: 28px;
  transform: rotate(12deg);
}

.hero::before {
  top: -40px;
  right: 110px;
  width: 140px;
  height: 140px;
  background: linear-gradient(135deg, rgba(255, 213, 79, 0.9), rgba(255, 138, 61, 0.9));
}

.hero::after {
  bottom: -50px;
  right: -10px;
  width: 220px;
  height: 220px;
  background: linear-gradient(135deg, rgba(80, 168, 255, 0.4), rgba(61, 230, 154, 0.3));
}

.nav,
.section-heading,
.quiz-toolbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}

.brand,
.eyebrow,
h1,
h2,
h3,
.category-chip,
.score-value {
  font-family: "Bungee", cursive;
}

.brand {
  max-width: 420px;
  font-size: 1.5rem;
  line-height: 1.2;
}

.nav-links,
.filter-group,
.hero-actions,
.category-strip,
.answer-grid {
  display: flex;
  gap: 0.8rem;
  flex-wrap: wrap;
}

.nav-links {
  align-items: center;
  justify-content: flex-end;
}

.hero-content {
  position: relative;
  z-index: 1;
  padding: 4rem 0 4.5rem;
  max-width: 760px;
  animation: rise 700ms ease-out both;
}

.eyebrow {
  margin: 0 0 0.65rem;
  color: var(--yellow);
  font-size: 0.95rem;
  letter-spacing: 0.06em;
}

h1 {
  margin: 0;
  font-size: clamp(2.8rem, 7vw, 5.8rem);
  line-height: 1.04;
}

h2 {
  margin: 0;
  font-size: clamp(1.8rem, 4vw, 3rem);
  line-height: 1.15;
}

h3 {
  margin: 0;
  font-size: clamp(1.6rem, 3.4vw, 2.6rem);
  line-height: 1.2;
}

.hero-copy,
.quiz-feedback,
.section-heading p:last-child {
  color: var(--muted);
}

.hero-copy {
  max-width: 620px;
  margin: 1rem 0 0;
  font-size: 1.15rem;
  line-height: 1.75;
}

.button,
.sound-toggle,
.filter-button,
.answer-button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 48px;
  padding: 0.85rem 1.15rem;
  border-radius: 999px;
  transition: transform 160ms ease, box-shadow 160ms ease, background 160ms ease, border-color 160ms ease;
}

.button:hover,
.sound-toggle:hover,
.filter-button:hover,
.answer-button:hover {
  transform: translateY(-2px) scale(1.01);
}

.button-primary {
  background: linear-gradient(135deg, var(--yellow), var(--orange));
  color: #1f1632;
  font-weight: 800;
  box-shadow: 0 14px 30px rgba(255, 138, 61, 0.3);
}

.button-secondary,
.sound-toggle,
.filter-button,
.answer-button {
  color: var(--text);
  background: rgba(255, 255, 255, 0.06);
  border: 1px solid var(--line);
}

.filter-button.active,
.sound-toggle.is-muted {
  background: rgba(255, 213, 79, 0.18);
  border-color: rgba(255, 213, 79, 0.5);
}

.filter-button.active {
  background: linear-gradient(135deg, var(--yellow), var(--orange));
  border-color: transparent;
  color: #1f1632;
  font-weight: 800;
  box-shadow: 0 14px 30px rgba(255, 138, 61, 0.22);
}

.sound-toggle.is-muted {
  color: var(--yellow);
}

.category-strip,
.panel {
  margin-top: 1rem;
}

.category-chip {
  padding: 0.95rem 1.1rem;
  border-radius: 22px;
  font-size: 0.95rem;
  letter-spacing: 0.04em;
  border: 1px solid rgba(255, 255, 255, 0.14);
  background: rgba(255, 255, 255, 0.06);
  box-shadow: var(--shadow);
  animation: floatCard 3.2s ease-in-out infinite;
}

.category-chip.minecraft {
  background: linear-gradient(135deg, rgba(61, 230, 154, 0.28), rgba(80, 168, 255, 0.16));
}

.category-chip.weather {
  background: linear-gradient(135deg, rgba(80, 168, 255, 0.3), rgba(255, 213, 79, 0.16));
}

.category-chip.states {
  background: linear-gradient(135deg, rgba(255, 107, 199, 0.22), rgba(80, 168, 255, 0.16));
}

.category-chip.dinosaurs {
  background: linear-gradient(135deg, rgba(255, 138, 61, 0.26), rgba(61, 230, 154, 0.16));
}

.panel {
  padding: 1.35rem;
}

.section-heading {
  margin-bottom: 1.25rem;
}

.score-panel {
  display: flex;
  gap: 0.8rem;
  flex-wrap: wrap;
}

.score-badge {
  min-width: 110px;
  padding: 0.8rem 1rem;
  border-radius: 20px;
  background: rgba(255, 255, 255, 0.06);
  border: 1px solid var(--line);
  text-align: center;
}

.score-label {
  display: block;
  font-size: 0.8rem;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: 0.08em;
}

.score-value {
  display: block;
  margin-top: 0.35rem;
  font-size: 1.5rem;
}

.flashcard-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 1rem;
}

.flashcard {
  perspective: 1200px;
  min-height: 250px;
}

.flashcard-inner {
  position: relative;
  width: 100%;
  height: 100%;
  min-height: 250px;
  transform-style: preserve-3d;
  transition: transform 600ms ease;
}

.flashcard.is-flipped .flashcard-inner {
  transform: rotateY(180deg);
}

.flashcard-face {
  position: absolute;
  inset: 0;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  padding: 1.1rem;
  border-radius: 24px;
  border: 1px solid var(--line);
  backface-visibility: hidden;
  box-shadow: var(--shadow);
}

.flashcard-front {
  background: linear-gradient(180deg, rgba(18, 33, 79, 0.95), rgba(14, 22, 50, 0.95));
}

.flashcard-back {
  background: linear-gradient(180deg, rgba(255, 213, 79, 0.98), rgba(255, 138, 61, 0.96));
  color: #281a00;
  transform: rotateY(180deg);
}

.flashcard-category,
.quiz-category {
  align-self: flex-start;
  padding: 0.35rem 0.7rem;
  border-radius: 999px;
  font-size: 0.72rem;
  font-weight: 800;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  background: linear-gradient(135deg, var(--yellow), var(--orange));
  color: #1f1632;
  box-shadow: 0 10px 20px rgba(255, 138, 61, 0.2);
}

.flashcard-back .flashcard-category {
  background: rgba(40, 26, 0, 0.12);
  color: #281a00;
  box-shadow: none;
}

.flashcard-question,
.flashcard-answer {
  margin: 1rem 0;
  font-size: 1.2rem;
  font-weight: 800;
  line-height: 1.45;
}

.flashcard-question {
  color: #ffffff;
}

.flashcard-hint {
  color: var(--muted);
  font-size: 0.95rem;
}

.flashcard-back .flashcard-hint {
  color: rgba(40, 26, 0, 0.76);
}

.quiz-board {
  display: grid;
  gap: 1rem;
}

.quiz-card {
  padding: 1.4rem;
  border-radius: 24px;
  background: linear-gradient(180deg, rgba(18, 33, 79, 0.92), rgba(14, 22, 50, 0.96));
  border: 1px solid var(--line);
  box-shadow: var(--shadow);
}

.quiz-category {
  margin-bottom: 1rem;
}

.answer-grid {
  margin-top: 1.2rem;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.answer-button {
  min-height: 72px;
  padding: 1rem;
  border-radius: 20px;
  font-weight: 800;
  text-align: left;
}

.answer-button.correct {
  background: rgba(61, 230, 154, 0.22);
  border-color: rgba(61, 230, 154, 0.75);
}

.answer-button.wrong {
  background: rgba(255, 107, 199, 0.22);
  border-color: rgba(255, 107, 199, 0.75);
}

.answer-button.dimmed {
  opacity: 0.72;
}

.quiz-feedback {
  min-height: 1.7rem;
  margin: 1rem 0 0;
  font-size: 1rem;
  font-weight: 700;
}

.pop-in {
  animation: popIn 280ms ease-out;
}

@keyframes rise {
  from {
    opacity: 0;
    transform: translateY(24px);
  }

  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes popIn {
  0% {
    transform: scale(0.94);
  }

  60% {
    transform: scale(1.03);
  }

  100% {
    transform: scale(1);
  }
}

@keyframes floatCard {
  0%,
  100% {
    transform: translateY(0);
  }

  50% {
    transform: translateY(-5px);
  }
}

@media (max-width: 1024px) {
  .flashcard-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (max-width: 860px) {
  .nav,
  .section-heading,
  .quiz-toolbar {
    align-items: flex-start;
    flex-direction: column;
  }

  .hero-content {
    padding: 3rem 0 4rem;
  }

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

@media (max-width: 640px) {
  .page-shell {
    width: min(100% - 0.8rem, 1180px);
  }

  .hero,
  .panel,
  .flashcard-face,
  .quiz-card {
    border-radius: 22px;
  }

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

  h1 {
    font-size: clamp(2.5rem, 13vw, 4rem);
  }

  .brand {
    font-size: 1.2rem;
  }
}