:root{--bg-app:#050510;--bg-panel:#0d0d1f;--bg-input:#111827;--bg-card:#0a0b1e;--text-main:#fff;--text-dim:#88a;--text-muted:#666;--border-subtle:#ffffff12;--border-focus:#818cf880;--accent:var(--calc-color-math);--accent-rgb:129, 140, 248;--primary:#818cf8;--primary-light:#4f46e5}*,:before,:after{box-sizing:border-box}body{background-color:var(--bg-app);color:var(--calc-text-primary);margin:0;padding:0;font-family:Inter,sans-serif;line-height:1.6}.main-container{max-width:960px;margin:0 auto;padding:0 20px 24px}.calc-breadcrumb{color:var(--calc-text-muted);padding:10px 20px;font-size:.85rem}.calc-breadcrumb a{color:var(--calc-text-dim);text-decoration:none}.calc-breadcrumb a:hover{color:var(--primary)}.calc-title{text-align:center;letter-spacing:-.02em;color:var(--calc-text-primary);margin:10px 0 4px;font-size:2rem;font-weight:800}.calc-subtitle{text-align:center;color:var(--calc-text-dim);margin:0 0 20px;font-size:1rem}.tab-nav{background:var(--bg-input);border:1px solid var(--border-subtle);border-radius:12px;gap:4px;margin-bottom:20px;padding:4px;display:flex}.tab-btn{color:var(--calc-text-dim);cursor:pointer;background:0 0;border:none;border-radius:8px;flex:1;padding:8px 16px;font-family:inherit;font-size:.9rem;font-weight:600;transition:color .2s,background .2s}.tab-btn:hover{color:var(--calc-text-primary);background:#ffffff0a}.tab-btn.active{background:var(--primary);color:#fff}.tab-content{display:none}.tab-content.active{display:block}.card{background:var(--bg-panel);border:1px solid var(--border-subtle);border-radius:16px;padding:1.5rem}.input-card{border-left:3px solid var(--primary)}.result-card{border-left:3px solid #818cf866;margin-top:16px}.form-group{margin-bottom:14px}.form-label{color:var(--calc-text-dim);text-transform:uppercase;letter-spacing:.05em;margin-bottom:6px;font-size:.8rem;font-weight:600;display:block}.start-row{grid-template-columns:1fr 1.4fr;gap:12px;margin-bottom:4px;display:grid}.preset-row{flex-wrap:wrap;gap:8px;margin-bottom:18px;display:flex}.preset-chip{color:var(--primary);cursor:pointer;background:#818cf814;border:1px solid #818cf838;border-radius:20px;padding:5px 14px;font-family:inherit;font-size:.82rem;font-weight:600;transition:background .15s,border-color .15s}.preset-chip:hover{background:#818cf829;border-color:#818cf866}.preset-chip.active{background:var(--primary);color:#fff;border-color:var(--primary)}.section-label{color:var(--calc-text-dim);text-transform:uppercase;letter-spacing:.08em;border-bottom:1px solid var(--border-subtle);margin-bottom:10px;padding-bottom:8px;font-size:.75rem;font-weight:700}.factors-wrap{flex-direction:column;gap:10px;margin:4px 0 12px;display:flex}.factor-row{align-items:center;gap:10px;display:flex}.factor-idx-badge{width:24px;height:24px;color:var(--primary);background:#818cf81f;border:1px solid #818cf840;border-radius:50%;flex-shrink:0;justify-content:center;align-items:center;font-size:.7rem;font-weight:700;display:flex}.factor-fraction{border:1px solid var(--border-subtle);background:#ffffff05;border-radius:10px;flex:1;overflow:hidden}.factor-num-wrap,.factor-den-wrap{align-items:center;gap:6px;padding:6px 10px;display:flex}.factor-fl-label{text-transform:uppercase;letter-spacing:.07em;color:var(--calc-text-muted);flex-shrink:0;width:22px;font-size:.6rem;font-weight:700}.factor-input{width:100%;color:var(--calc-text-primary);background:0 0;border:none;outline:none;padding:0;font-family:inherit;font-size:.9rem}.factor-input::placeholder{color:#fff3;font-size:.83rem}.factor-divider{background:#818cf84d;height:1px;margin:0}.btn-remove-factor{cursor:pointer;width:28px;height:28px;color:var(--calc-text-muted);background:0 0;border:1px solid #ffffff14;border-radius:6px;flex-shrink:0;justify-content:center;align-items:center;font-family:inherit;font-size:1rem;line-height:1;transition:color .15s,border-color .15s;display:flex}.btn-remove-factor:hover{color:#fb7185;border-color:#fb71854d}.btn-add-factor{color:var(--primary);cursor:pointer;background:#818cf812;border:1px dashed #818cf84d;border-radius:8px;width:100%;margin-top:4px;padding:8px 16px;font-family:inherit;font-size:.88rem;font-weight:600;transition:background .15s,border-color .15s}.btn-add-factor:hover{background:#818cf821;border-color:#818cf880}.btn-add-factor:disabled{opacity:.4;cursor:not-allowed}.chain-section-label{text-transform:uppercase;letter-spacing:.08em;color:var(--calc-text-dim);margin:18px 0 8px;font-size:.72rem;font-weight:700}.chain-wrap{background:#818cf80a;border:1px solid #818cf826;border-radius:12px;align-items:center;min-height:80px;padding:16px;display:flex;overflow-x:auto}.chain-inner{align-items:center;gap:10px;min-width:max-content;display:flex}.chain-placeholder{color:var(--calc-text-muted);font-size:.88rem;font-style:italic}.chain-op{color:var(--calc-text-dim);flex-shrink:0;padding:0 2px;font-size:1.3rem;font-weight:500}.chain-term{flex-direction:column;flex-shrink:0;align-items:center;display:flex}.chain-num,.chain-den{white-space:nowrap;padding:3px 8px;font-family:Courier New,monospace;font-size:.88rem}.chain-num{color:var(--calc-text-primary)}.chain-den{color:var(--calc-text-dim)}.chain-bar{background:#818cf866;align-self:stretch;width:100%;min-width:40px;height:1px;margin:1px 0}.ct-val{color:var(--calc-text-primary);font-weight:700}.ct-unit{color:var(--calc-text-dim)}.ct-unit.cancelled{color:#4b556380;opacity:.7;text-decoration:line-through}.chain-result{background:#818cf81a;border:1px solid #818cf840;border-radius:10px;flex-direction:column;align-items:center;padding:4px 12px;display:flex}.chain-result-val{color:var(--primary);font-family:Courier New,monospace;font-size:1.15rem;font-weight:800;line-height:1.2}.chain-result-unit{color:var(--calc-text-dim);font-family:Courier New,monospace;font-size:.8rem}.result-card .hero-result{text-align:center;padding:16px 10px 12px}.hero-label{color:var(--calc-text-dim);text-transform:uppercase;letter-spacing:.08em;margin-bottom:6px;font-size:.72rem;font-weight:700}.hero-value{color:var(--primary);letter-spacing:-.02em;word-break:break-all;margin-bottom:4px;font-size:2.2rem;font-weight:800;line-height:1.1}.hero-unit{color:var(--calc-text-primary);margin-bottom:6px;font-family:Courier New,monospace;font-size:1rem;font-weight:600}.hero-sub{color:var(--calc-text-dim);font-size:.85rem}.factor-badge{color:var(--primary);background:#818cf81a;border:1px solid #818cf838;border-radius:20px;align-items:center;gap:5px;margin-top:8px;padding:3px 12px;font-size:.76rem;font-weight:600;display:inline-flex}.act-row{flex-wrap:wrap;gap:10px;margin-top:14px;display:flex}.act-btn{color:var(--calc-text-dim);cursor:pointer;background:#ffffff0a;border:1px solid #ffffff1a;border-radius:8px;padding:8px 16px;font-family:inherit;font-size:.84rem;font-weight:600;transition:color .2s,background .2s,border-color .2s}.act-btn:hover{color:var(--primary);background:#818cf81a;border-color:#818cf84d}.conv-cat-title{color:var(--primary);text-transform:uppercase;letter-spacing:.06em;border-bottom:1px solid #818cf833;margin:18px 0 6px;padding-bottom:5px;font-size:.78rem;font-weight:700}.conv-cat-title:first-child{margin-top:4px}.conv-table{border-collapse:collapse;width:100%;margin-bottom:4px;font-size:.87rem}.conv-table th{color:var(--primary);text-align:left;text-transform:uppercase;letter-spacing:.05em;background:#818cf812;border-bottom:1px solid #818cf82e;padding:8px 12px;font-size:.72rem}.conv-table td{color:var(--calc-text-dim);cursor:pointer;border-bottom:1px solid #ffffff0a;padding:8px 12px;transition:background .12s}.conv-table tr:hover td{color:var(--calc-text-primary);background:#818cf80f}.conv-table td.conv-arrow{color:var(--primary);text-align:center;cursor:default;font-weight:700}.conv-table .load-btn{color:var(--primary);cursor:pointer;white-space:nowrap;background:#818cf81a;border:1px solid #818cf840;border-radius:6px;padding:3px 10px;font-family:inherit;font-size:.78rem;font-weight:600;transition:background .12s}.conv-table .load-btn:hover{background:#818cf833}.practice-grid{flex-direction:column;gap:14px;margin-top:4px;display:flex}.practice-card{border:1px solid var(--border-subtle);background:#ffffff05;border-radius:12px;padding:16px}.practice-card-header{justify-content:space-between;align-items:flex-start;gap:12px;margin-bottom:10px;display:flex}.practice-num{text-transform:uppercase;letter-spacing:.07em;color:var(--primary);background:#818cf81a;border-radius:4px;flex-shrink:0;padding:2px 8px;font-size:.68rem;font-weight:700}.practice-title{color:var(--calc-text-primary);flex:1;font-size:.92rem;font-weight:600}.btn-load-problem{background:var(--primary);color:#fff;cursor:pointer;border:none;border-radius:7px;flex-shrink:0;padding:5px 14px;font-family:inherit;font-size:.8rem;font-weight:700;transition:opacity .15s}.btn-load-problem:hover{opacity:.85}.practice-chain{color:var(--calc-text-dim);background:#ffffff05;border-radius:8px;margin-bottom:8px;padding:8px 12px;font-family:Courier New,monospace;font-size:.82rem;line-height:1.8}.practice-answer{color:var(--calc-text-dim);font-size:.82rem}.practice-answer strong{color:var(--primary)}.table-scroll{overflow-x:auto}@media (width<=768px){.main-container{padding:0 12px 20px}.calc-title{font-size:1.6rem}.start-row{grid-template-columns:1fr}.chain-wrap{padding:12px}.hero-value{font-size:1.8rem}.practice-card-header{flex-direction:column;gap:8px}}@media (width<=480px){.tab-btn{padding:7px 8px;font-size:.78rem}.preset-row{gap:6px}.preset-chip{padding:4px 10px;font-size:.76rem}}[data-theme=light]{--bg-app:#e8edf5;--bg-panel:#fff;--bg-input:#f0f4f9;--bg-card:#fff;--text-main:#0f172a;--text-dim:#334155;--text-muted:#64748b;--border-subtle:#0000001f;--border-focus:#4f46e580;--primary:#4f46e5;--accent-rgb:79, 70, 229}[data-theme=light] body{color:#0f172a;background-color:#e8edf5}[data-theme=light] .calc-breadcrumb a{color:#334155}[data-theme=light] .calc-breadcrumb a:hover{color:#4f46e5}[data-theme=light] .calc-title{color:#0f172a}[data-theme=light] .calc-subtitle{color:#475569}[data-theme=light] .tab-nav{background:#f0f4f9;border-color:#0000001a}[data-theme=light] .tab-btn{color:#475569}[data-theme=light] .tab-btn:hover{color:#0f172a;background:#0000000a}[data-theme=light] .tab-btn.active{color:#fff;background:#4f46e5}[data-theme=light] .card{background:#fff;border-color:#0000001f;box-shadow:0 2px 8px #00000014}[data-theme=light] .input-card{border-left-color:#4f46e5}[data-theme=light] .result-card{border-left-color:#4f46e580}[data-theme=light] .form-label{color:#475569}[data-theme=light] .preset-chip{color:#4f46e5;background:#4f46e512;border-color:#4f46e538}[data-theme=light] .preset-chip:hover{background:#4f46e521;border-color:#4f46e566}[data-theme=light] .preset-chip.active{color:#fff;background:#4f46e5}[data-theme=light] .section-label{color:#475569;border-color:#0000001a}[data-theme=light] .factor-idx-badge{color:#4f46e5;background:#4f46e514;border-color:#4f46e533}[data-theme=light] .factor-fraction{background:#f8fafc;border-color:#0000001f}[data-theme=light] .factor-fl-label{color:#94a3b8}[data-theme=light] .factor-input{color:#0f172a}[data-theme=light] .factor-input::placeholder{color:#00000040}[data-theme=light] .factor-divider{background:#4f46e533}[data-theme=light] .btn-remove-factor{color:#94a3b8;border-color:#0000001a}[data-theme=light] .btn-add-factor{color:#4f46e5;background:#4f46e50f;border-color:#4f46e540}[data-theme=light] .btn-add-factor:hover{background:#4f46e51f;border-color:#4f46e573}[data-theme=light] .chain-section-label{color:#475569}[data-theme=light] .chain-wrap{background:#4f46e50a;border-color:#4f46e526}[data-theme=light] .chain-op{color:#94a3b8}[data-theme=light] .chain-num{color:#0f172a}[data-theme=light] .chain-den{color:#475569}[data-theme=light] .chain-bar{background:#4f46e54d}[data-theme=light] .ct-val{color:#0f172a}[data-theme=light] .ct-unit{color:#475569}[data-theme=light] .ct-unit.cancelled{color:#94a3b8;opacity:.8}[data-theme=light] .chain-result{background:#4f46e514;border-color:#4f46e540}[data-theme=light] .chain-result-val{color:#4f46e5}[data-theme=light] .chain-result-unit{color:#475569}[data-theme=light] .hero-value{color:#4f46e5}[data-theme=light] .hero-unit{color:#0f172a}[data-theme=light] .hero-label{color:#475569}[data-theme=light] .hero-sub{color:#64748b}[data-theme=light] .factor-badge{color:#4f46e5;background:#4f46e514;border-color:#4f46e533}[data-theme=light] .act-btn{color:#334155;background:#f0f4f9;border-color:#0000001f}[data-theme=light] .act-btn:hover{color:#4f46e5;background:#4f46e514;border-color:#4f46e547}[data-theme=light] .conv-cat-title{color:#4f46e5;border-color:#4f46e533}[data-theme=light] .conv-table th{color:#4f46e5;background:#4f46e512;border-color:#4f46e52e}[data-theme=light] .conv-table td{color:#334155;border-color:#0000000f}[data-theme=light] .conv-table tr:hover td{color:#0f172a;background:#f0f4f9}[data-theme=light] .conv-table .load-btn{color:#4f46e5;background:#4f46e514;border-color:#4f46e538}[data-theme=light] .conv-table .load-btn:hover{background:#4f46e529}[data-theme=light] .practice-card{background:#f8fafc;border-color:#0000001a}[data-theme=light] .practice-num{color:#4f46e5;background:#4f46e514}[data-theme=light] .practice-title{color:#0f172a}[data-theme=light] .btn-load-problem{background:#4f46e5}[data-theme=light] .practice-chain{color:#334155;background:#00000008}[data-theme=light] .practice-answer{color:#475569}[data-theme=light] .practice-answer strong{color:#4f46e5}