/* Custom Styles for English 1200 Words Platform */
@import url('https://fonts.googleapis.com/css2?family=Plus+Jakarta+Sans:wght@400;500;600;700;800&family=Noto+Sans+TC:wght@400;500;700;900&display=swap');

:root {
  --primary: #4f46e5;
  --primary-hover: #4338ca;
  --secondary: #06b6d4;
  --accent: #f59e0b;
}

body {
  font-family: 'Plus Jakarta Sans', 'Noto Sans TC', sans-serif;
  background-color: #f8fafc;
  color: #1e293b;
  overflow-x: hidden;
  -webkit-tap-highlight-color: transparent;
}

/* Card 3D Flip */
.flip-card {
  perspective: 1000px;
}
.flip-card-inner {
  position: relative;
  width: 100%;
  height: 100%;
  text-align: center;
  transition: transform 0.6s cubic-bezier(0.4, 0, 0.2, 1);
  transform-style: preserve-3d;
}
.flip-card.flipped .flip-card-inner {
  transform: rotateY(180deg);
}
.flip-card-front, .flip-card-back {
  position: absolute;
  width: 100%;
  height: 100%;
  backface-visibility: hidden;
  -webkit-backface-visibility: hidden;
  border-radius: 1.5rem;
}
.flip-card-back {
  transform: rotateY(180deg);
}

/* Touch targets optimization */
button, select, input {
  touch-action: manipulation;
}

/* Custom Scrollbar */
::-webkit-scrollbar {
  width: 6px;
  height: 6px;
}
::-webkit-scrollbar-track {
  background: #f1f5f9;
}
::-webkit-scrollbar-thumb {
  background: #cbd5e1;
  border-radius: 9999px;
}
::-webkit-scrollbar-thumb:hover {
  background: #94a3b8;
}

/* Quiz Option Hover & Touch effect */
.quiz-choice-btn {
  transition: all 0.15s ease-in-out;
  min-height: 60px;
}
.quiz-choice-btn:active:not(:disabled) {
  transform: scale(0.98);
}
@media (hover: hover) {
  .quiz-choice-btn:hover:not(:disabled) {
    transform: translateY(-2px);
    box-shadow: 0 6px 16px -4px rgba(79, 70, 229, 0.15);
  }
}

/* Animations */
@keyframes fadeIn {
  from { opacity: 0; transform: translateY(6px); }
  to { opacity: 1; transform: translateY(0); }
}
.animate-fade-in {
  animation: fadeIn 0.25s ease-out forwards;
}