/* ===== RESET & BASE ===== */
*, *::before, *::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

:root {
  --bg-deep: #0a0e27;
  --bg-card: #141837;
  --bg-card-hover: #1a2045;
  --accent: #4a6cf7;
  --accent-dim: rgba(74, 108, 247, 0.3);
  --accent-glow: rgba(74, 108, 247, 0.5);
  --success: #00e676;
  --success-dim: rgba(0, 230, 118, 0.3);
  --danger: #ff3d71;
  --danger-dim: rgba(255, 61, 113, 0.3);
  --text: #e0e6ff;
  --text-muted: #6b7db3;
  --radius: 16px;
  --radius-sm: 10px;
}

body {
  background: var(--bg-deep);
  color: var(--text);
  font-family: 'Segoe UI', system-ui, -apple-system, sans-serif;
  min-height: 100vh;
  overflow: hidden;
}

/* ===== SCREENS ===== */
.screen {
  display: none;
  width: 100vw;
  height: 100vh;
  position: absolute;
  top: 0;
  left: 0;
}

.screen.active {
  display: flex;
  align-items: center;
  justify-content: center;
  animation: fadeIn 0.4s ease;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(12px); }
  to { opacity: 1; transform: translateY(0); }
}

/* ===== BUTTONS ===== */
.btn {
  border: none;
  cursor: pointer;
  font-size: 1.1rem;
  font-weight: 600;
  padding: 14px 36px;
  border-radius: var(--radius);
  transition: all 0.25s ease;
  letter-spacing: 0.02em;
}

.btn-primary {
  background: var(--accent);
  color: #fff;
  box-shadow: 0 0 20px var(--accent-dim), 0 0 60px rgba(74, 108, 247, 0.1);
}

.btn-primary:hover {
  background: #5b7bf9;
  box-shadow: 0 0 30px var(--accent-glow), 0 0 80px rgba(74, 108, 247, 0.2);
  transform: translateY(-2px);
}

.btn-primary:active {
  transform: translateY(0);
}

.btn-secondary {
  background: var(--bg-card);
  color: var(--text);
  border: 1px solid rgba(74, 108, 247, 0.3);
  box-shadow: 0 0 12px rgba(74, 108, 247, 0.08);
}

.btn-secondary:hover {
  background: var(--bg-card-hover);
  border-color: var(--accent);
  box-shadow: 0 0 20px var(--accent-dim);
  transform: translateY(-2px);
}

.btn-combat {
  background: linear-gradient(135deg, var(--accent), #7c3aed);
  color: #fff;
  box-shadow: 0 0 20px var(--accent-dim), 0 0 40px rgba(124, 58, 237, 0.15);
  font-size: 1.2rem;
  padding: 16px 48px;
}

.btn-combat:hover:not(:disabled) {
  box-shadow: 0 0 35px var(--accent-glow), 0 0 70px rgba(124, 58, 237, 0.25);
  transform: translateY(-2px);
}

.btn-combat:disabled {
  opacity: 0.35;
  cursor: not-allowed;
}

/* ===== HOME SCREEN ===== */
.home-container {
  text-align: center;
}

.title-glow {
  font-size: 3.5rem;
  font-weight: 800;
  background: linear-gradient(135deg, var(--text), var(--accent));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  text-shadow: none;
  filter: drop-shadow(0 0 30px var(--accent-dim));
  margin-bottom: 12px;
}

.subtitle {
  color: var(--text-muted);
  font-size: 1.15rem;
  margin-bottom: 40px;
}

.hint {
  color: var(--text-muted);
  font-size: 0.85rem;
  margin-top: 16px;
}

/* Lesson Grid */
.lesson-grid {
  display: grid;
  grid-template-columns: repeat(6, 1fr);
  gap: 12px;
  margin-top: 24px;
  max-width: 480px;
}

.lesson-btn {
  background: var(--bg-card);
  border: 1px solid rgba(74, 108, 247, 0.2);
  color: var(--text);
  font-size: 1.1rem;
  font-weight: 700;
  width: 60px;
  height: 60px;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: all 0.25s ease;
  box-shadow: 0 0 12px rgba(74, 108, 247, 0.06);
  display: flex;
  align-items: center;
  justify-content: center;
}

.lesson-btn:hover {
  background: var(--bg-card-hover);
  border-color: var(--accent);
  box-shadow: 0 0 20px var(--accent-dim), 0 0 50px rgba(74, 108, 247, 0.08);
  transform: translateY(-2px);
}

/* ===== FLASHCARD SCREEN ===== */
.screen#screen-flashcard {
  flex-direction: column;
  padding: 24px;
  gap: 20px;
}

.flashcard-header {
  display: flex;
  align-items: center;
  gap: 16px;
  width: 100%;
  max-width: 500px;
}

.progress-bar-container {
  flex: 1;
  height: 6px;
  background: rgba(74, 108, 247, 0.12);
  border-radius: 3px;
  overflow: hidden;
}

.progress-bar-fill {
  height: 100%;
  background: var(--accent);
  border-radius: 3px;
  transition: width 0.4s ease;
  box-shadow: 0 0 8px var(--accent-dim);
  width: 10%;
}

.counter {
  color: var(--text-muted);
  font-size: 0.9rem;
  white-space: nowrap;
}

/* Card */
.flashcard-area {
  display: flex;
  align-items: center;
  gap: 20px;
}

.card {
  width: 420px;
  height: 210px;
  perspective: 1000px;
  cursor: pointer;
  outline: none;
}

.card-inner {
  width: 100%;
  height: 100%;
  position: relative;
  transform-style: preserve-3d;
  transition: transform 0.6s cubic-bezier(0.4, 0, 0.2, 1);
}

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

.card-front, .card-back {
  position: absolute;
  inset: 0;
  backface-visibility: hidden;
  -webkit-backface-visibility: hidden;
  border-radius: var(--radius);
  background: var(--bg-card);
  border: 1px solid rgba(74, 108, 247, 0.2);
  box-shadow:
    0 0 20px rgba(74, 108, 247, 0.12),
    0 0 60px rgba(74, 108, 247, 0.06),
    inset 0 1px 0 rgba(255, 255, 255, 0.04);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 24px;
  gap: 8px;
}

.card-back {
  transform: rotateY(180deg);
  gap: 20px;
}

.card-back-row {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
}

.card-label {
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--accent);
  font-weight: 600;
}

.card-word {
  font-size: 2rem;
  font-weight: 700;
}

.card-hint {
  font-size: 0.8rem;
  color: var(--text-muted);
  margin-top: 8px;
}

.card:hover .card-inner {
  box-shadow:
    0 0 30px rgba(74, 108, 247, 0.2),
    0 0 80px rgba(74, 108, 247, 0.08);
}

/* Nav Buttons */
.nav-btn {
  background: var(--bg-card);
  border: 1px solid rgba(74, 108, 247, 0.2);
  color: var(--text);
  font-size: 2rem;
  width: 48px;
  height: 48px;
  border-radius: 50%;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all 0.2s ease;
  box-shadow: 0 0 12px rgba(74, 108, 247, 0.08);
}

.nav-btn:hover {
  background: var(--bg-card-hover);
  border-color: var(--accent);
  box-shadow: 0 0 20px var(--accent-dim);
}

.flashcard-footer {
  margin-top: 10px;
}

/* ===== COMBAT SCREEN ===== */
.screen#screen-combat {
  flex-direction: column;
  position: relative;
}

#combat-canvas {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
  z-index: 10;
}

.combat-layout {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  width: 100%;
  max-width: 960px;
  gap: 32px;
  padding: 24px;
  z-index: 1;
}

.combat-arena {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 48px;
  width: 100%;
  max-width: 800px;
}

.arena-vs {
  font-size: 1.2rem;
  font-weight: 800;
  color: var(--text-muted);
  letter-spacing: 0.1em;
  text-transform: uppercase;
}

/* Combatants */
.combatant {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 10px;
  min-width: 140px;
}

.combatant-label {
  font-size: 0.85rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--text-muted);
  font-weight: 600;
}

.hp-bar-container {
  width: 120px;
  height: 8px;
  background: rgba(255, 255, 255, 0.06);
  border-radius: 4px;
  overflow: hidden;
}

.hp-bar-fill {
  height: 100%;
  border-radius: 4px;
  transition: width 0.5s ease;
  width: 100%;
}

.player-hp {
  background: var(--success);
  box-shadow: 0 0 10px var(--success-dim);
}

.enemy-hp {
  background: var(--danger);
  box-shadow: 0 0 10px var(--danger-dim);
}

.hp-text {
  font-size: 0.8rem;
  color: var(--text-muted);
  font-variant-numeric: tabular-nums;
}

/* Orbs */
.orb {
  width: 80px;
  height: 80px;
  border-radius: 50%;
  transition: all 0.5s ease;
}

.player-orb {
  background: radial-gradient(circle at 35% 35%, #5bffa8, #00c853, #007a33);
  box-shadow:
    0 0 20px rgba(0, 230, 118, 0.4),
    0 0 60px rgba(0, 230, 118, 0.15),
    inset 0 -4px 12px rgba(0, 0, 0, 0.3);
}

.enemy-orb {
  background: radial-gradient(circle at 35% 35%, #ff7e9a, #ff3d71, #b71c4b);
  box-shadow:
    0 0 20px rgba(255, 61, 113, 0.4),
    0 0 60px rgba(255, 61, 113, 0.15),
    inset 0 -4px 12px rgba(0, 0, 0, 0.3);
}

.orb.pulse {
  animation: orbPulse 0.3s ease;
}

@keyframes orbPulse {
  0% { transform: scale(1); }
  50% { transform: scale(0.88); filter: brightness(1.4); }
  100% { transform: scale(1); }
}

.orb.dim {
  filter: brightness(0.4);
  box-shadow: none;
}

/* Combat Center */
.combat-center {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 16px;
  width: 100%;
  max-width: 400px;
}

.combat-verb {
  font-size: 2.4rem;
  font-weight: 800;
  background: linear-gradient(135deg, var(--text), var(--accent));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  filter: drop-shadow(0 0 16px var(--accent-dim));
}

.combat-input-area {
  width: 100%;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
}

.combat-input {
  width: 100%;
  padding: 14px 20px;
  font-size: 1.2rem;
  font-family: inherit;
  background: var(--bg-card);
  color: var(--text);
  border: 1px solid rgba(74, 108, 247, 0.25);
  border-radius: var(--radius-sm);
  outline: none;
  text-align: center;
  transition: all 0.25s ease;
  box-shadow: 0 0 12px rgba(74, 108, 247, 0.06);
}

.combat-input:focus {
  border-color: var(--accent);
  box-shadow: 0 0 20px var(--accent-dim), 0 0 50px rgba(74, 108, 247, 0.08);
}

.combat-input.shake {
  animation: shake 0.4s ease;
}

.combat-input.wrong-char {
  color: var(--danger);
  text-shadow: 0 0 8px var(--danger-dim);
}

@keyframes shake {
  0%, 100% { transform: translateX(0); }
  20% { transform: translateX(-8px); }
  40% { transform: translateX(8px); }
  60% { transform: translateX(-5px); }
  80% { transform: translateX(5px); }
}

.input-hint {
  font-size: 0.78rem;
  color: var(--text-muted);
}

.combat-feedback {
  min-height: 28px;
  font-size: 1rem;
  font-weight: 600;
  text-align: center;
  transition: opacity 0.3s ease;
}

.combat-feedback.correct {
  color: var(--success);
  text-shadow: 0 0 12px var(--success-dim);
}

.combat-feedback.wrong {
  color: var(--danger);
  text-shadow: 0 0 12px var(--danger-dim);
}

/* ===== RESULTS SCREEN ===== */
.results-container {
  text-align: center;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 28px;
}

.results-banner {
  font-size: 2.8rem;
  font-weight: 800;
}

.results-banner.victory {
  background: linear-gradient(135deg, var(--success), #69f0ae);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  filter: drop-shadow(0 0 24px var(--success-dim));
}

.results-banner.defeat {
  background: linear-gradient(135deg, var(--danger), #ff8a9e);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  filter: drop-shadow(0 0 24px var(--danger-dim));
}

.results-stats {
  display: flex;
  gap: 40px;
}

.stat {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 6px;
  background: var(--bg-card);
  border: 1px solid rgba(74, 108, 247, 0.15);
  border-radius: var(--radius);
  padding: 20px 28px;
  box-shadow: 0 0 16px rgba(74, 108, 247, 0.06);
}

.stat-value {
  font-size: 2rem;
  font-weight: 800;
  color: var(--accent);
}

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

.results-hp {
  display: flex;
  gap: 32px;
  color: var(--text-muted);
  font-size: 0.95rem;
}

.results-buttons {
  display: flex;
  gap: 16px;
}

/* ===== RESPONSIVE ===== */
@media (max-width: 700px) {
  .title-glow { font-size: 2.4rem; }
  .card { width: 300px; height: 150px; }
  .card-word { font-size: 1.6rem; }
  .combat-arena { gap: 20px; }
  .orb { width: 50px; height: 50px; }
  .combat-verb { font-size: 1.8rem; }
  .results-stats { gap: 16px; }
  .stat { padding: 14px 18px; }
  .stat-value { font-size: 1.4rem; }
}