body>[data-astro-cid-yoabahbm]:not(header):not(footer):not(#cookie-banner):not(main):not(.container):not(#app):not(#screen-start){width:100%;max-width:var(--max-width);margin-inline:auto;padding-inline:.8rem}.container-main{max-width:900px;margin:0 auto;padding:2rem .8rem}.page-title{font-size:1.875rem;font-weight:700;color:var(--purple-primary);margin:0;letter-spacing:-.5px}.subtitle{color:var(--text-muted);font-weight:600;margin-top:.25rem;font-size:.875rem}.game-header{display:flex;flex-direction:column;gap:1rem;margin-bottom:1.5rem}@media(min-width:768px){.game-header{flex-direction:row;justify-content:space-between;align-items:flex-start}}.controls-group{display:flex;flex-direction:column;gap:.5rem;width:100%}@media(min-width:640px){.controls-group{flex-direction:row;width:auto;gap:1rem}}.video-link{display:inline-flex;align-items:center;gap:.5rem;font-size:1rem;font-weight:600;color:var(--purple-primary);text-decoration:none;transition:all .2s ease}.video-link:hover{color:var(--purple-base)}.mode-select,.difficulty-select{padding:.5rem 2rem .5rem 1rem;border-radius:.75rem;font-weight:600;font-size:1rem;border:2px solid var(--border-color);background:var(--bg-color);color:var(--text-color);cursor:pointer;transition:all .2s ease;appearance:none;background-image:url("data:image/svg+xml;charset=UTF-8,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%23674ea7' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3e%3cpolyline points='6 9 12 15 18 9'%3e%3c/polyline%3e%3c/svg%3e");background-repeat:no-repeat;background-position:right .5rem center;background-size:1.5em 1.5em}.mode-select:hover,.difficulty-select:hover{border-color:var(--purple-primary);background-color:var(--bg-card-hover)}.mode-select:focus,.difficulty-select:focus{outline:none;border-color:var(--purple-primary);box-shadow:0 0 0 4px #674ea726}.mode-select option,.difficulty-select option{padding:1rem;background:var(--bg-color);color:var(--text-color)}.mode-select option:checked,.difficulty-select option:checked{background:linear-gradient(var(--purple-primary),var(--purple-primary));background-color:var(--purple-primary);color:#fff}.mode-option-free{background:#f0fdf4!important;color:#166534!important}.mode-option-free:checked{background:#22c55e!important;color:#fff!important}.mode-option-classic{background:#eff6ff!important;color:#1e40af!important}.mode-option-classic:checked{background:#3b82f6!important;color:#fff!important}.difficulty-option-easy{background:#dcfce7!important;color:#166534!important}.difficulty-option-easy:checked{background:#10b981!important;color:#fff!important}.difficulty-option-medium{background:#fef3c7!important;color:#b45309!important}.difficulty-option-medium:checked{background:#f59e0b!important;color:#fff!important}.difficulty-option-hard{background:#fee2e2!important;color:#991b1b!important}.difficulty-option-hard:checked{background:#ef4444!important;color:#fff!important}.btn-primary{background:var(--purple-primary);color:#fff;padding:1rem 1.5rem;border:none;border-radius:1rem;font-weight:700;cursor:pointer;transition:all .2s ease;white-space:nowrap}.btn-primary:hover{background:var(--purple-base);transform:translateY(-2px);box-shadow:0 8px 20px #674ea74d}.btn-primary:active{transform:translateY(0)}.btn-large{padding:1rem 1.5rem;font-size:.875rem;width:100%}@media(min-width:640px){.btn-large{width:auto}}.btn-check{padding:1rem 1.5rem;font-size:1rem;min-width:200px}.btn-secondary{background:var(--bg-card);color:var(--text-color);padding:1rem 1.5rem;border:2px solid var(--border-color);border-radius:1rem;font-weight:700;font-size:.875rem;cursor:pointer;transition:all .2s ease;width:100%}@media(min-width:640px){.btn-secondary{width:auto}}.btn-secondary:hover{background:var(--border-color);border-color:var(--purple-primary)}.instruction-box{padding:1rem 1.5rem;border-radius:1rem;text-align:center;font-weight:700;font-size:.875rem;border:2px solid var(--border-color);margin-bottom:1.5rem;transition:all .2s ease;width:100%;word-wrap:break-word;overflow-wrap:break-word}.instruction-warning,.instruction-error{background:#fee2e2;color:#991b1b;border-color:#fecaca}.instruction-success{background:#dcfce7;color:#166534;border-color:#bbf7d0}.instruction-info{background:var(--bg-card-hover);color:#6b21a8;border-color:#ddd6fe}.instruction-hard{background:#f3e8ff;color:#6b21a8;border-color:#e9d5ff}.game-area{margin-bottom:1.5rem}.game-container{display:flex;justify-content:center;align-items:center;padding:1.5rem 0;gap:1.5rem;position:relative}.minus-symbol{font-size:3.5rem;color:#cbd5e1;font-weight:700;display:none}@media(min-width:768px){.minus-symbol{display:block;position:absolute;left:-40px}}.math-grid{display:flex;flex-direction:row-reverse;gap:2px;justify-content:center;flex-wrap:wrap;font-family:Arial,Calibri,Trebuchet MS,sans-serif}.math-font{font-family:Arial,Calibri,Trebuchet MS,sans-serif}.digit-column{display:flex;flex-direction:column;align-items:center;width:90px;position:relative}.button-container{height:44px;display:flex;align-items:center;margin-bottom:.5rem}.button-spacer{height:36px;margin-bottom:.5rem}.digit-main{font-size:4rem;margin-bottom:.25rem;color:var(--text-color);font-weight:700;transition:all .2s ease;line-height:1}.digit-sub{font-size:4rem;margin-bottom:.5rem;color:var(--text-color);font-weight:700;line-height:1}.digit-line{width:100%;height:3px;background:var(--text-color);border-radius:2px;margin-bottom:.5rem}.strikethrough{position:relative;color:var(--text-muted)}.strikethrough:after{content:"";position:absolute;top:50%;left:-10%;width:120%;height:3px;background:var(--red-base);transform:rotate(-45deg);border-radius:2px;opacity:.8}.borrowed-val{font-size:1.75rem;color:var(--red-base);height:40px;font-weight:700;display:flex;align-items:center;justify-content:center;transition:all .2s ease;line-height:1}.input-result{width:80px;height:90px;text-align:center;font-size:2.5rem;border:3px solid var(--border-color);border-radius:.75rem;background:var(--bg-color);transition:all .2s ease;margin-top:.25rem;font-family:Arial,Calibri,Trebuchet MS,sans-serif;font-weight:700;color:var(--text-color);line-height:1}.input-result::-webkit-outer-spin-button,.input-result::-webkit-inner-spin-button{-webkit-appearance:none;margin:0}.input-result:focus{outline:none;border-color:var(--purple-primary);background:var(--bg-card-hover);box-shadow:0 0 0 4px #674ea726}.step1{background:#f8fafc;border-color:#cbd5e1;margin-bottom:.5rem}.step1:disabled{background:#e2e8f0;border-color:#cbd5e1;color:#64748b;cursor:not-allowed}.step2{background:#f0fdf4;border-color:#86efac;color:#166534}.input-result.hidden{display:none}.btn-toggle-action{font-size:.6rem;padding:.25rem;border-radius:.75rem;cursor:pointer;font-weight:700;transition:all .2s ease;text-transform:uppercase;width:80px;height:32px;display:flex;align-items:center;justify-content:center;text-align:center;border:2px solid}.state-borrow{background:#dbeafe;color:#0c4a6e;border-color:#bfdbfe}.state-borrow:hover:not(.btn-disabled){background:var(--purple-primary);color:#fff;border-color:var(--purple-primary);transform:translateY(-1px)}.state-return{background:#fee2e2;color:#7f1d1d;border-color:#fecaca}.state-return:hover{background:var(--red-base);color:#fff;border-color:var(--red-base);transform:translateY(-1px)}.btn-disabled{opacity:.5;cursor:not-allowed;pointer-events:none}.button-group{display:flex;flex-direction:column;gap:.5rem;justify-content:center;align-items:center;margin-top:1.5rem}@media(min-width:640px){.button-group{flex-direction:row;gap:1rem}}.feedback-box{text-align:center;font-weight:700;padding:1.5rem 2rem;border-radius:1rem;border:2px solid;font-size:1rem;margin-top:1.5rem;transition:all .2s ease}.feedback-success{background:#dcfce7;color:#166534;border-color:#86efac}.feedback-error{background:#fee2e2;color:#991b1b;border-color:#fecaca}.feedback-warning{background:#fef3c7;color:#b45309;border-color:#fcd34d}.hidden{display:none}.highlight-error{color:var(--red-base)!important;animation:shake .5s ease-in-out}.hard-mode-display{text-align:center;font-size:2rem;margin:1.5rem 0}.hard-number{margin-bottom:1rem;font-size:4rem;font-weight:700;color:var(--text-color);line-height:1.2}.hard-divider{border-top:4px solid var(--text-color);padding-top:1rem;margin:1rem 0}.hard-inputs{display:flex;flex-direction:row-reverse;gap:1rem;justify-content:center;flex-wrap:wrap;margin-top:1.5rem}@keyframes shake{0%,to{transform:translate(0)}25%{transform:translate(-4px)}75%{transform:translate(4px)}}