body{font-family:Inter,system-ui,-apple-system,sans-serif;background:#030712;margin:0;padding:0;min-height:100vh;color:#e2e8f0}.container{width:100%;padding:16px 0;background:#ffffff08;backdrop-filter:blur(12px);-webkit-backdrop-filter:blur(12px);border-bottom:1px solid rgba(255,255,255,.06);margin-bottom:32px}header{max-width:900px;margin:0 auto;padding:0 20px;display:flex;justify-content:space-between;align-items:center}h1{margin:0;font-size:1.25rem;font-weight:600;letter-spacing:-.01em;color:#ffffffe6}.controls-top{display:flex;gap:12px;margin-bottom:28px;align-items:center}#set-selector{padding:10px 16px;border-radius:8px;border:1px solid rgba(255,255,255,.08);background:#ffffff0a;color:#e2e8f0;font-size:.9rem;font-weight:500;cursor:pointer;outline:none;transition:border-color .15s,box-shadow .15s;-webkit-appearance:none}#set-selector:focus{border-color:#6366f180;box-shadow:0 0 0 2px #6366f133}#set-selector option{background:#0f172a;color:#e2e8f0}.header-btn,.nav-btn{padding:10px 20px;border-radius:8px;border:1px solid rgba(255,255,255,.08);background:#ffffff0a;color:#e2e8f0;font-weight:500;font-size:.9rem;cursor:pointer;transition:background .15s,border-color .15s}.header-btn:hover,.nav-btn:hover{background:#ffffff14;border-color:#ffffff24}#flashcard-game-container{width:100%;max-width:800px;margin:0 auto;box-sizing:border-box;display:flex;flex-direction:column;align-items:center;padding:0 20px}.progress-container{width:100%;height:3px;background:#ffffff0f;border-radius:2px;margin-bottom:24px;overflow:hidden}#progress-bar{height:100%;width:0%;background:linear-gradient(90deg,#6366f1,#818cf8);transition:width .15s linear}#card-display{width:100%;height:400px;perspective:1200px;margin-bottom:24px;display:flex;align-items:center;justify-content:center}.flashcard-empty-state{width:100%;min-height:220px;display:grid;place-items:center;padding:2rem;text-align:center;border-radius:16px;border:1px solid rgba(255,255,255,.06);background:#ffffff08;color:#cbd5e1;font-weight:600}.card{width:100%;height:100%;cursor:pointer;position:relative;box-sizing:border-box;margin:0 auto;touch-action:none;overscroll-behavior:contain;-webkit-user-select:none;-moz-user-select:none;user-select:none}.card-inner{position:relative;width:100%;height:100%;transition:transform .5s cubic-bezier(.4,0,.2,1);transform-style:preserve-3d;transform-origin:center center;box-sizing:border-box}.card.flipped .card-inner{transform:rotateX(180deg)}.card-front,.card-back{position:absolute;width:100%;height:100%;backface-visibility:hidden;border-radius:16px;background:#ffffff08;backdrop-filter:blur(16px);-webkit-backdrop-filter:blur(16px);border:1px solid rgba(255,255,255,.06);display:flex;flex-direction:column;align-items:center;justify-content:center;padding:40px;text-align:center}.card-audio-btn{position:absolute;top:18px;right:18px;width:42px;height:42px;border-radius:999px;border:1px solid rgba(255,255,255,.1);background:#0f172aad;color:#f8fafc;display:inline-flex;align-items:center;justify-content:center;cursor:pointer;transition:transform .15s ease,background .15s ease,border-color .15s ease,color .15s ease;z-index:3}.card-audio-btn:hover{transform:translateY(-1px);background:#4f46e529;border-color:#818cf86b}.card-audio-btn:disabled{opacity:.55;cursor:default}.card-audio-btn .card-audio-icon-loader,.card-audio-btn.is-loading .card-audio-icon-play{display:none}.card-audio-btn.is-loading .card-audio-icon-loader{display:inline-flex}.card-audio-btn.is-loading svg{animation:flashcard-audio-spin .9s linear infinite}.card-audio-btn.is-error{background:#7f1d1d4d;border-color:#f8717180;color:#fecaca}@keyframes flashcard-audio-spin{0%{transform:rotate(0)}to{transform:rotate(360deg)}}.card-front img{max-width:220px;max-height:220px;-o-object-fit:contain;object-fit:contain;margin-bottom:24px;border-radius:10px;opacity:.92}.card-front-text-only{gap:0}.card-front{top:50%;left:0;right:0;transform:translateY(-46%);z-index:2;box-sizing:border-box}.card-back{top:50%;left:0;right:0;transform:translateY(-54%) rotateX(180deg);z-index:1;box-sizing:border-box}.word-en,.word-pt{font-size:2.8rem;font-weight:800;color:#f1f5f9;letter-spacing:-.02em}.navigation-controls{display:flex;align-items:center;justify-content:center;gap:28px;width:100%;margin-bottom:40px}#card-counter{font-weight:400;font-size:.95rem;color:#64748b;font-variant-numeric:tabular-nums}.nav-btn{width:48px;height:48px;display:flex;align-items:center;justify-content:center;border-radius:50%;font-size:1.25rem;padding:0}@media(max-width:600px){#card-display{height:300px}.word-en,.word-pt{font-size:1.8rem}.card-front img{max-width:160px;max-height:160px}.card-audio-btn{top:14px;right:14px;width:38px;height:38px}}#overlay{position:fixed;top:0;right:0;bottom:0;left:0;background:#030712d9;display:none;align-items:center;justify-content:center;z-index:1000;backdrop-filter:blur(8px);-webkit-backdrop-filter:blur(8px)}#finish-message{background:#ffffff0a;backdrop-filter:blur(20px);-webkit-backdrop-filter:blur(20px);border:1px solid rgba(255,255,255,.08);border-radius:16px;padding:40px;text-align:center;max-width:400px;width:90%}#finish-message h2{margin-bottom:24px;font-size:1.5rem;font-weight:700;color:#f1f5f9}#finish-message button{margin:6px}@media(max-width:520px){#finish-message{width:min(92vw,360px);padding:22px 16px;border-radius:14px}}