:root{--blue: #2563eb;--blue-l: #dbeafe;--blue-d: #1d4ed8;--green: #16a34a;--green-l: #dcfce7;--red: #dc2626;--red-l: #fee2e2;--yellow: #b45309;--yellow-l: #fef9c3;--bg: #f0f4f8;--card: #fff;--border: #e2e8f0;--text: #1e293b;--muted: #64748b;--shadow: 0 1px 3px rgba(0, 0, 0, .1), 0 4px 6px rgba(0, 0, 0, .05);--r: 12px;--r-sm: 8px}[data-theme=dark]{--bg: #0f172a;--card: #1e293b;--border: #334155;--text: #f1f5f9;--muted: #94a3b8;--shadow: 0 1px 3px rgba(0, 0, 0, .4), 0 4px 6px rgba(0, 0, 0, .3)}*,*:before,*:after{box-sizing:border-box;margin:0;padding:0}body{font-family:system-ui,-apple-system,sans-serif;background:var(--bg);color:var(--text);min-height:100vh}button{cursor:pointer;font-family:inherit}input,textarea{font-family:inherit}.app{display:flex;flex-direction:column;min-height:100vh;max-width:640px;margin:0 auto}.theme-btn{background:none;border:none;font-size:1.2rem;padding:4px 6px;border-radius:var(--r-sm);cursor:pointer;line-height:1;color:var(--text)}.hdr{background:var(--card);border-bottom:1px solid var(--border);padding:12px 16px;display:flex;align-items:center;justify-content:space-between;position:sticky;top:0;z-index:10}.logo{font-size:1.1rem;font-weight:700;color:var(--blue);display:flex;align-items:center;gap:6px}.hdr-right{display:flex;align-items:center;gap:8px}.badge{padding:4px 10px;border-radius:99px;font-weight:600;font-size:.8rem}.streak-badge{background:var(--yellow-l);color:var(--yellow)}.lvl-badge{background:var(--blue-l);color:var(--blue)}.day-bar{background:var(--card);padding:6px 16px 10px;border-bottom:1px solid var(--border)}.bar-lbl{font-size:.7rem;color:var(--muted);margin-bottom:4px}.bar-track{height:6px;background:var(--border);border-radius:99px;overflow:hidden}.bar-fill{height:100%;background:var(--blue);border-radius:99px;transition:width .4s ease}.main{flex:1;padding:20px 16px 80px}.card{background:var(--card);border-radius:var(--r);padding:24px;box-shadow:var(--shadow);margin-bottom:16px}.card-meta{display:flex;justify-content:space-between;align-items:center;margin-bottom:16px}.topic-tag{font-size:.7rem;font-weight:600;text-transform:uppercase;letter-spacing:.5px;color:var(--muted)}.type-tag{font-size:.7rem;padding:3px 8px;border-radius:99px;background:var(--blue-l);color:var(--blue);font-weight:500}.q-text{font-size:1.35rem;font-weight:600;line-height:1.45;margin-bottom:24px}.q-ctx{font-size:.8rem;color:var(--muted);margin-top:-18px;margin-bottom:20px;font-style:italic}.choices{display:grid;gap:10px}.c-btn{padding:13px 16px;border:2px solid var(--border);border-radius:var(--r-sm);background:var(--card);text-align:left;font-size:.95rem;color:var(--text);transition:all .15s}.c-btn:hover:not(:disabled){border-color:var(--blue);background:var(--blue-l)}.c-btn.ok{border-color:var(--green)!important;background:var(--green-l)!important;color:var(--green);font-weight:600}.c-btn.bad{border-color:var(--red)!important;background:var(--red-l)!important;color:var(--red)}.c-btn:disabled{cursor:default}.inp-area{display:flex;gap:8px}.ans-inp{flex:1;padding:12px 14px;border:2px solid var(--border);border-radius:var(--r-sm);font-size:1rem;color:var(--text);background:var(--card);outline:none;transition:border-color .15s}.ans-inp:focus{border-color:var(--blue)}.sub-btn{padding:12px 20px;background:var(--blue);color:#fff;border:none;border-radius:var(--r-sm);font-size:1rem;font-weight:600;transition:background .15s}.sub-btn:hover:not(:disabled){background:var(--blue-d)}.sub-btn:disabled{background:var(--muted)}.hint-wrap{margin-top:14px}.hint-btn{background:none;border:1px dashed var(--border);padding:7px 14px;border-radius:var(--r-sm);color:var(--muted);font-size:.85rem;transition:all .15s}.hint-btn:hover:not(:disabled){border-color:var(--yellow);color:var(--yellow);background:var(--yellow-l)}.hint-box{margin-top:8px;padding:12px;background:var(--yellow-l);border-radius:var(--r-sm);font-size:.875rem;color:var(--yellow)}.fb{margin-top:18px;padding:16px;border-radius:var(--r-sm)}.fb.ok{background:var(--green-l)}.fb.bad{background:var(--red-l)}.fb-hd{display:flex;align-items:center;gap:8px;font-weight:700;font-size:1rem;margin-bottom:8px}.fb.ok .fb-hd{color:var(--green)}.fb.bad .fb-hd{color:var(--red)}.fb-txt{font-size:.9rem;color:var(--text);line-height:1.5}.fb-exp{font-size:.8rem;color:var(--muted);margin-top:8px;line-height:1.5}.ai-loading{display:flex;align-items:center;gap:8px;color:var(--muted);font-size:.875rem;padding:8px 0}.spin{width:16px;height:16px;border:2px solid var(--border);border-top-color:var(--blue);border-radius:50%;animation:spin .8s linear infinite;flex-shrink:0}@keyframes spin{to{transform:rotate(360deg)}}.next-btn{margin-top:16px;width:100%;padding:14px;background:var(--blue);color:#fff;border:none;border-radius:var(--r-sm);font-size:1rem;font-weight:600;transition:background .15s}.next-btn:hover{background:var(--blue-d)}.done{text-align:center;padding:40px 20px}.done-icon{font-size:3.5rem;margin-bottom:16px}.done-title{font-size:1.5rem;font-weight:700;margin-bottom:8px}.done-sub{color:var(--muted);margin-bottom:28px}.stats-row{display:flex;justify-content:center;gap:32px;margin-bottom:28px}.s-item{text-align:center}.s-val{font-size:2rem;font-weight:700;color:var(--blue)}.s-lbl{font-size:.7rem;color:var(--muted);text-transform:uppercase;margin-top:2px}.chat-cta{padding:12px 24px;background:var(--blue);color:#fff;border:none;border-radius:var(--r-sm);font-size:1rem;font-weight:600;transition:background .15s}.chat-cta:hover{background:var(--blue-d)}.loader{text-align:center;padding:60px 20px;color:var(--muted)}.big-spin{width:40px;height:40px;border:3px solid var(--border);border-top-color:var(--blue);border-radius:50%;animation:spin 1s linear infinite;margin:0 auto 16px}.chat-wrap{display:flex;flex-direction:column;height:calc(100vh - 200px)}.topic-sel select{width:100%;padding:10px 12px;border:2px solid var(--border);border-radius:var(--r-sm);font-size:.9rem;background:var(--card);color:var(--text);outline:none;margin-bottom:12px}.chat-msgs{flex:1;overflow-y:auto;display:flex;flex-direction:column;gap:12px;padding:4px 0}.bubble{max-width:85%;padding:12px 14px;border-radius:12px;font-size:.9rem;line-height:1.5}.bubble.u{background:var(--blue);color:#fff;align-self:flex-end;border-bottom-right-radius:4px}.bubble.a{background:var(--card);color:var(--text);align-self:flex-start;border-bottom-left-radius:4px;box-shadow:var(--shadow)}.bubble .trans{margin-top:6px;font-size:.78rem;opacity:.7}.bubble.a .trans{color:var(--muted)}.bubble .corr{margin-top:6px;font-size:.78rem;color:var(--red);border-top:1px solid var(--red-l);padding-top:6px}.chat-inp-area{display:flex;gap:8px;padding-top:12px}.chat-inp{flex:1;padding:11px 14px;border:2px solid var(--border);border-radius:var(--r-sm);font-size:.9rem;color:var(--text);background:var(--card);outline:none;transition:border-color .15s;resize:none;height:44px}.chat-inp:focus{border-color:var(--blue)}.send-btn{padding:11px 16px;background:var(--blue);color:#fff;border:none;border-radius:var(--r-sm);font-size:1.1rem;transition:background .15s}.send-btn:hover:not(:disabled){background:var(--blue-d)}.send-btn:disabled{background:var(--muted)}.chat-empty{flex:1;display:flex;flex-direction:column;align-items:center;justify-content:center;text-align:center;color:var(--muted);gap:8px}.chat-empty-ic{font-size:2.5rem}.stats-grid{display:grid;grid-template-columns:1fr 1fr;gap:12px;margin-bottom:16px}.s-card{background:var(--card);padding:16px;border-radius:var(--r);box-shadow:var(--shadow);text-align:center}.s-card-val{font-size:2rem;font-weight:700;color:var(--blue)}.s-card-lbl{font-size:.7rem;color:var(--muted);text-transform:uppercase;margin-top:4px}.lvl-card{background:var(--card);padding:20px;border-radius:var(--r);box-shadow:var(--shadow)}.lvl-title{font-weight:700;margin-bottom:12px}.lvl-bar-track{height:8px;background:var(--border);border-radius:99px;overflow:hidden;margin-top:8px}.lvl-bar-fill{height:100%;background:var(--blue);border-radius:99px;transition:width .5s ease}.lvl-labels{display:flex;justify-content:space-between;font-size:.7rem;color:var(--muted);margin-top:4px}.refresh-btn{margin-top:16px;width:100%;padding:12px;background:var(--blue-l);color:var(--blue);border:2px solid var(--blue-l);border-radius:var(--r-sm);font-size:.9rem;font-weight:600;transition:all .15s}.refresh-btn:hover{background:var(--blue-d);color:#fff}.bnav{position:fixed;bottom:0;left:0;right:0;background:var(--card);border-top:1px solid var(--border);display:flex;max-width:640px;margin:0 auto}.n-btn{flex:1;padding:11px 8px;border:none;background:none;font-size:.72rem;color:var(--muted);display:flex;flex-direction:column;align-items:center;gap:3px;transition:color .15s}.n-btn span{font-size:1.3rem}.n-btn.on{color:var(--blue)}.fc-controls{display:flex;gap:8px;margin-bottom:16px}.fc-filter{padding:7px 14px;border:2px solid var(--border);border-radius:99px;background:var(--card);color:var(--muted);font-size:.85rem;font-weight:500;cursor:pointer;transition:all .15s;font-family:inherit}.fc-filter.on{border-color:var(--blue);background:var(--blue-l);color:var(--blue)}.fc-count{text-align:center;font-size:.8rem;color:var(--muted);margin-bottom:12px}.flashcard{perspective:1200px;height:220px;margin-bottom:16px;cursor:pointer;-webkit-user-select:none;user-select:none}.fc-inner{position:relative;width:100%;height:100%;transition:transform .6s cubic-bezier(.4,0,.2,1);transform-style:preserve-3d}.flashcard.flipped .fc-inner{transform:rotateY(180deg)}.fc-face{position:absolute;top:0;right:0;bottom:0;left:0;backface-visibility:hidden;background:var(--card);border-radius:var(--r);padding:24px;box-shadow:var(--shadow);display:flex;flex-direction:column;align-items:center;justify-content:center;text-align:center;gap:6px}.fc-back{transform:rotateY(180deg)}.fc-word{font-size:1.5rem;font-weight:700;color:var(--text)}.fc-sub{font-size:.85rem;color:var(--muted);font-style:italic}.fc-tap{font-size:.72rem;color:var(--muted);margin-top:6px}.fc-ratings{display:grid;grid-template-columns:repeat(4,1fr);gap:8px;margin-top:4px}.fc-rate{padding:11px 4px;border:2px solid;border-radius:var(--r-sm);background:var(--card);font-size:.8rem;font-weight:700;cursor:pointer;transition:opacity .15s;font-family:inherit}.fc-rate:hover{opacity:.75}.fc-rate.again{border-color:var(--red);color:var(--red)}.fc-rate.hard{border-color:var(--yellow);color:var(--yellow)}.fc-rate.good{border-color:var(--blue);color:var(--blue)}.fc-rate.easy{border-color:var(--green);color:var(--green)}.cit-hdr{display:flex;justify-content:space-between;align-items:center;margin-bottom:4px}.cit-lbl{font-size:.75rem;color:var(--muted)}.cit-bar{height:4px;background:var(--border);border-radius:99px;overflow:hidden;margin-bottom:16px}.cit-fill{height:100%;background:var(--green);border-radius:99px;transition:width .4s}.login-overlay{position:fixed;top:0;right:0;bottom:0;left:0;background:var(--bg);display:flex;align-items:center;justify-content:center;z-index:999;padding:20px}.login-card{background:var(--card);border-radius:var(--r);padding:36px 28px;box-shadow:var(--shadow);width:100%;max-width:360px;text-align:center}.login-logo{font-size:2.5rem;margin-bottom:8px}.login-title{font-size:1.3rem;font-weight:700;color:var(--text);margin-bottom:4px}.login-sub{font-size:.85rem;color:var(--muted);margin-bottom:24px}.login-inp{width:100%;padding:12px 14px;border:2px solid var(--border);border-radius:var(--r-sm);font-size:1rem;color:var(--text);background:var(--card);outline:none;transition:border-color .15s;margin-bottom:12px;font-family:inherit}.login-inp:focus{border-color:var(--blue)}.login-btn{width:100%;padding:13px;background:var(--blue);color:#fff;border:none;border-radius:var(--r-sm);font-size:1rem;font-weight:600;cursor:pointer;transition:background .15s}.login-btn:hover:not(:disabled){background:var(--blue-d)}.login-btn:disabled{background:var(--muted)}.login-err{margin-top:10px;font-size:.85rem;color:var(--red);min-height:1.2em}.toast{position:fixed;top:70px;left:50%;transform:translate(-50%);background:var(--text);color:#fff;padding:9px 20px;border-radius:99px;font-size:.85rem;z-index:100;opacity:0;transition:opacity .3s;pointer-events:none;white-space:nowrap}.toast.on{opacity:1}