.flashcard-wrapper{max-width:1200px;margin:0 auto;padding:20px}.flashcard-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(90px,1fr));gap:12px}.card{border:1px solid #ddd;border-radius:12px;padding:18px 8px;text-align:center;font-size:22px;background:#fff;cursor:pointer}#popup{position:fixed;inset:0;background:rgba(0,0,0,.45);z-index:999999;display:none}.popup-box{position:fixed;top:50%;left:50%;transform:translate(-50%,-50%);width:90%;max-width:320px;background:#fff;border-radius:16px;padding:20px;text-align:center}#popup-hanzi{font-size:36px;margin-bottom:6px}#popup-pinyin{font-size:18px;margin-bottom:6px}#popup-thai{font-size:16px}@media (max-width:768px){.flashcard-grid{grid-template-columns:repeat(3,1fr)}}@media (max-width:480px){.flashcard-grid{grid-template-columns:repeat(2,1fr)}}