*,*:before,*:after{box-sizing:border-box;margin:0;padding:0}:root{--bg-deep: #050010;--bg-mid: #0a0020;--bg-surface: rgba(255,150,255,.06);--border-dim: rgba(200,100,255,.25);--border-active: #c090ff;--border-correct: #66ff99;--border-carry: rgba(255,200,80,.4);--border-carry-active: #ffcc55;--text-primary: #f0e8ff;--text-dim: rgba(200,150,255,.5);--text-correct: #88ffbb;--text-carry: #ffcc55;--glow-purple: 0 0 12px rgba(200,100,255,.35);--glow-gold: 0 0 8px rgba(255,200,50,.4);--glow-green: 0 0 10px rgba(100,255,150,.3);--font-mono: "Courier New", Courier, monospace}body{background:radial-gradient(ellipse at 20% 20%,#1a0050 0%,var(--bg-mid) 50%,var(--bg-deep) 100%);min-height:100vh;font-family:Segoe UI,sans-serif;color:var(--text-primary)}.app{display:flex;flex-direction:column;align-items:center;min-height:100vh}.header{width:100%;display:flex;align-items:center;justify-content:space-between;padding:16px 24px;background:#ff96ff0d;border-bottom:1px solid var(--border-dim)}.logo{font-size:1.1rem;font-weight:700;letter-spacing:2px;color:#e0b0ff}.mode-toggle{display:flex;gap:0;background:#c864ff14;border:1px solid var(--border-dim);border-radius:24px;padding:4px;margin:20px 0 0}.mode-btn{padding:8px 24px;border-radius:20px;font-size:.9rem;cursor:pointer;color:var(--text-dim);border:none;background:transparent;font-family:inherit;transition:all .2s}.mode-btn.active{background:#c864ff4d;color:var(--text-primary);font-weight:600}.custom-form{display:flex;flex-direction:column;align-items:center;gap:16px;padding:20px}.number-inputs{display:flex;align-items:flex-end;gap:12px}.num-field{display:flex;flex-direction:column;align-items:center;gap:6px}.num-label{font-size:.65rem;letter-spacing:2px;text-transform:uppercase;color:var(--text-dim)}.num-input{width:90px;height:52px;background:#c864ff1a;border:2px solid var(--border-dim);border-radius:10px;text-align:center;font-size:1.4rem;font-family:var(--font-mono);color:var(--text-primary);outline:none}.num-input:focus{border-color:var(--border-active);box-shadow:var(--glow-purple)}.times-sign{font-size:1.6rem;color:var(--text-dim);padding-bottom:10px}.action-btn{padding:12px 32px;background:linear-gradient(135deg,#c864ff4d,#9632dc66);border:1px solid rgba(200,100,255,.5);border-radius:24px;color:var(--text-primary);font-size:1rem;font-weight:600;cursor:pointer;letter-spacing:1px;font-family:inherit;transition:all .2s}.action-btn:disabled{opacity:.4;cursor:not-allowed}.score-bar{display:flex;gap:16px}.badge{background:#c864ff26;border:1px solid rgba(200,100,255,.4);border-radius:20px;padding:5px 14px;font-size:.85rem;color:#d8aaff;display:flex;align-items:center;gap:6px}.badge.gold{border-color:#ffc83266;background:#ffc8321a;color:#ffd966}.problem-card{background:var(--bg-surface);border:1px solid var(--border-dim);border-radius:16px;padding:28px 36px;margin:24px 0;-webkit-backdrop-filter:blur(4px);backdrop-filter:blur(4px)}.problem-label{font-size:.7rem;letter-spacing:3px;text-transform:uppercase;color:var(--text-dim);margin-bottom:20px;text-align:center}.mult-grid{display:flex;flex-direction:column;align-items:flex-end;gap:2px;font-family:var(--font-mono)}.mult-row{display:flex;align-items:center;gap:4px}.row-prefix{width:28px;text-align:right;color:var(--text-dim);font-size:1.2rem;margin-right:4px;flex-shrink:0}.cell-fixed{width:36px;height:44px;display:flex;align-items:center;justify-content:center;font-size:1.5rem;color:#e0c8ff}.digit-input{width:36px;height:44px;background:#c864ff14;border:2px solid var(--border-dim);border-radius:8px;display:flex;align-items:center;justify-content:center;font-size:1.5rem;font-family:var(--font-mono);color:var(--text-primary);transition:all .2s;-webkit-user-select:none;user-select:none}.digit-input.future{border-color:#c864ff1f;background:transparent;color:#c896ff33}.digit-input.active{border-color:var(--border-active);background:#c864ff33;box-shadow:var(--glow-purple)}.digit-input.correct{border-color:var(--border-correct);background:#64ff961f;color:var(--text-correct)}.digit-input.blank{border-color:transparent;background:transparent;pointer-events:none}.carry-input{width:22px;height:22px;border:1.5px solid var(--border-carry);border-radius:4px;background:#ffc8320f;display:flex;align-items:center;justify-content:center;font-size:.75rem;font-family:var(--font-mono);color:var(--text-carry);transition:all .2s;-webkit-user-select:none;user-select:none}.carry-input.future{border-color:#ffc8321a;background:transparent;color:transparent}.carry-input.active{border-color:var(--border-carry-active);background:#ffc83233;box-shadow:var(--glow-gold)}.carry-input.correct{border-color:#ffc83299;background:#ffc8321f;color:var(--text-carry)}.carry-row{display:flex;align-items:flex-end;gap:4px}.carry-slot{width:36px;height:26px;display:flex;align-items:center;justify-content:center}.cell-fixed.hint-source{color:#fc5;text-shadow:0 0 10px rgba(255,200,50,.7);background:#ffc8321f;border-radius:6px}.digit-input.hint-target{border-color:#ffc832b3;box-shadow:0 0 10px #ffc83259}.carry-input.hint-target{border-color:#ffc832e6;box-shadow:0 0 8px #ffc83280}.hint-box{display:flex;align-items:center;gap:6px;margin-top:14px;padding:12px 18px;background:#ffc83214;border:1px solid rgba(255,200,50,.3);border-radius:10px;font-family:var(--font-mono);animation:fadeIn .2s ease}.hint-text{font-size:.8rem;color:#ffc832b3;letter-spacing:.5px;font-family:Segoe UI,sans-serif;white-space:nowrap}.hint-factor{font-size:1.3rem;color:#fc5;font-weight:700;text-shadow:0 0 8px rgba(255,200,50,.5)}.hint-op{font-size:1.1rem;color:#ffc83299}.hint-result-cell{display:inline-flex;align-items:center;justify-content:center;width:28px;height:34px;border:2px solid rgba(255,200,50,.4);border-radius:6px;background:#ffc8320d;font-size:1.1rem;color:#fc5;transition:all .15s}.hint-result-cell.hint-result-active{border-color:#fc5;background:#ffc83233;box-shadow:0 0 8px #ffc83280}.hint-result-cell.hint-result-filled{border-color:#ffc83299;background:#ffc8321f}.separator{width:100%;height:1px;background:linear-gradient(to right,transparent,var(--border-dim),transparent);margin:6px 0}.keypad{display:grid;grid-template-columns:repeat(5,52px);gap:8px;margin:0 0 24px}.key{height:52px;background:#c864ff1f;border:1px solid var(--border-dim);border-radius:10px;display:flex;align-items:center;justify-content:center;font-size:1.3rem;font-family:var(--font-mono);color:#d8aaff;cursor:pointer;transition:all .15s;-webkit-user-select:none;user-select:none}.key:active{transform:scale(.95)}.key.hint-key{background:#ffc8321a;border-color:#ffc83259;color:#ffd966;font-size:.9rem;font-family:inherit}.key.new-key{background:#c864ff33;border-color:#c864ff80;color:var(--text-primary);font-size:.9rem;font-family:inherit;letter-spacing:1px}.toast{position:fixed;bottom:24px;left:50%;transform:translate(-50%);background:#64ff9626;border:1px solid rgba(100,255,150,.4);border-radius:12px;padding:10px 24px;color:var(--text-correct);font-size:.95rem;pointer-events:none;animation:fadeIn .2s ease}.toast.error-toast{background:#ff646426;border-color:#ff646466;color:#f99}@keyframes shake{0%,to{transform:translate(0)}20%{transform:translate(-4px)}40%{transform:translate(4px)}60%{transform:translate(-4px)}80%{transform:translate(4px)}}@keyframes fadeIn{0%{opacity:0;transform:translate(-50%) translateY(8px)}to{opacity:1;transform:translate(-50%) translateY(0)}}.shake{animation:shake .3s ease}.field-error{font-size:.75rem;color:#f99;margin-top:4px}.history-overlay{position:fixed;top:0;right:0;bottom:0;left:0;background:#0009;z-index:200;display:flex;justify-content:center;align-items:flex-start;padding-top:60px}.history-panel{background:#0d0025;border:1px solid var(--border-dim);border-radius:16px;width:min(560px,calc(100vw - 32px));max-height:calc(100vh - 100px);display:flex;flex-direction:column;overflow:hidden;box-shadow:0 16px 48px #000000b3}.history-header{display:flex;align-items:center;justify-content:space-between;padding:18px 20px;border-bottom:1px solid var(--border-dim);flex-shrink:0}.history-title{font-size:.8rem;letter-spacing:3px;text-transform:uppercase;color:var(--text-dim)}.history-close{background:transparent;border:none;color:var(--text-dim);font-size:1rem;cursor:pointer;padding:4px 8px;border-radius:6px;transition:color .15s}.history-close:hover{color:var(--text-primary)}.history-empty{padding:40px;text-align:center;color:var(--text-dim);font-size:.9rem}.history-list{overflow-y:auto;padding:8px 0}.history-entry{padding:12px 20px;border-bottom:1px solid rgba(200,100,255,.08);display:flex;flex-direction:column;gap:4px}.history-entry:last-child{border-bottom:none}.history-problem{font-family:var(--font-mono);font-size:1.1rem;color:#e0c8ff}.history-meta{display:flex;align-items:center;gap:12px;font-size:.78rem}.history-user{color:#c896ff99;font-weight:600}.history-mistakes{color:#f99}.history-mistakes.perfect{color:var(--text-correct)}.history-skipped{color:var(--text-dim);font-style:italic}.history-hint-badge{font-size:.75rem}.history-date{color:var(--text-dim);margin-left:auto}.landing{display:flex;flex-direction:column;align-items:center;gap:32px;padding:60px 16px}.landing-title{font-size:1.4rem;font-weight:600;color:#e0b0ff;letter-spacing:2px}.user-cards{display:flex;gap:24px;flex-wrap:wrap;justify-content:center}.user-card{display:flex;flex-direction:column;align-items:center;gap:12px;padding:32px 40px;background:var(--bg-surface);border:1px solid var(--border-dim);border-radius:20px;cursor:pointer;transition:all .2s;font-family:inherit;color:var(--text-primary);min-width:160px}.user-card:hover{border-color:var(--border-active);background:#c864ff1f;box-shadow:var(--glow-purple);transform:translateY(-2px)}.user-avatar{width:64px;height:64px;border-radius:50%;background:linear-gradient(135deg,#c864ff66,#9632dc80);border:2px solid var(--border-dim);display:flex;align-items:center;justify-content:center;font-size:1.8rem;font-weight:700;color:#e0c8ff}.user-name{font-size:1.2rem;font-weight:600;letter-spacing:1px}.user-range{font-size:.72rem;color:#c896ff99;font-family:var(--font-mono)}.user-score{font-size:.75rem;color:var(--text-dim)}.back-btn{background:transparent;border:1px solid var(--border-dim);border-radius:20px;padding:5px 14px;color:var(--text-dim);font-size:.85rem;cursor:pointer;font-family:inherit;transition:all .2s;white-space:nowrap}.back-btn:hover{border-color:var(--border-active);color:var(--text-primary)}.header-right{display:flex;align-items:center;gap:12px}.menu-wrap{position:relative}.menu-btn{width:36px;height:36px;border-radius:50%;background:#c864ff1a;border:1px solid var(--border-dim);color:var(--text-dim);font-size:1.1rem;cursor:pointer;display:flex;align-items:center;justify-content:center;transition:all .2s;font-family:inherit}.menu-btn:hover{border-color:var(--border-active);color:var(--text-primary)}.menu-popover{position:absolute;top:calc(100% + 8px);right:0;background:#0d0025;border:1px solid var(--border-dim);border-radius:14px;padding:20px;min-width:260px;display:flex;flex-direction:column;align-items:center;gap:14px;z-index:100;box-shadow:0 8px 32px #0009}.menu-label{font-size:.75rem;letter-spacing:2px;text-transform:uppercase;color:var(--text-dim);align-self:flex-start}