:root{--bg-color: #f8fafc;--panel-bg: #ffffff;--text-primary: #0f172a;--text-secondary: #475569;--accent-blue: #1e3a8a;--accent-hover: #1e40af;--border-color: #e2e8f0;--shadow: 0 4px 6px -1px rgb(0 0 0 / .1), 0 2px 4px -2px rgb(0 0 0 / .1);--input-bg: #f1f5f9;--success: #10b981;--transition: all .3s ease}[data-theme=dark]{--bg-color: #0d1117;--panel-bg: #161b22;--text-primary: #c9d1d9;--text-secondary: #8b949e;--accent-blue: #58a6ff;--accent-hover: #79c0ff;--border-color: #30363d;--shadow: 0 4px 10px rgba(0, 0, 0, .4);--input-bg: #0d1117}*{box-sizing:border-box;margin:0;padding:0}body{font-family:-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,Helvetica,Arial,sans-serif;background-color:var(--bg-color);color:var(--text-primary);transition:var(--transition);line-height:1.5}.app-container{max-width:900px;margin:0 auto;padding:2rem 1rem}.header{display:flex;justify-content:space-between;align-items:center;margin-bottom:2rem;padding-bottom:1rem;border-bottom:1px solid var(--border-color)}.logo-section{display:flex;align-items:center;gap:.75rem;font-size:1.5rem;font-weight:700;color:var(--accent-blue)}.controls{display:flex;gap:1rem;align-items:center}.btn-icon{background:transparent;border:none;color:var(--text-secondary);cursor:pointer;font-size:1.5rem;transition:var(--transition);display:flex;align-items:center;justify-content:center;padding:.5rem;border-radius:50%}.btn-icon:hover{color:var(--accent-blue);background-color:var(--input-bg)}.theme-switch{position:relative;width:60px;height:30px;background-color:var(--input-bg);border:1px solid var(--border-color);border-radius:15px;cursor:pointer;display:flex;align-items:center;transition:var(--transition);padding:0;outline:none}.theme-switch:hover{border-color:var(--accent-blue)}.theme-switch.active{background-color:var(--accent-blue)}.switch-icon{position:absolute;top:50%;transform:translateY(-50%);display:flex;font-size:14px;transition:opacity .3s ease;pointer-events:none}.switch-icon.sun{left:8px;color:#f59e0b}.switch-icon.moon{right:8px;color:#fff}.switch-thumb{position:absolute;left:2px;top:2px;width:24px;height:24px;background-color:#fff;border-radius:50%;display:flex;align-items:center;justify-content:center;transition:transform .3s cubic-bezier(.4,0,.2,1);box-shadow:0 1px 3px #0003;color:#f59e0b;font-size:14px}.theme-switch.active .switch-thumb{transform:translate(30px);color:var(--accent-blue)}.card{background-color:var(--panel-bg);border-radius:12px;box-shadow:var(--shadow);padding:1.5rem;margin-bottom:1.5rem;border:1px solid var(--border-color);transition:var(--transition)}.card-title{font-size:1.25rem;font-weight:600;margin-bottom:1rem;color:var(--text-primary);display:flex;align-items:center;gap:.5rem}.form-group{margin-bottom:1rem}.form-group label{display:block;font-size:.875rem;font-weight:500;margin-bottom:.5rem;color:var(--text-secondary)}.input-container{display:flex;align-items:center;gap:.5rem}input,select{width:100%;padding:.75rem;border:1px solid var(--border-color);border-radius:6px;background-color:var(--input-bg);color:var(--text-primary);font-size:16px;transition:var(--transition)}input[type=number]::-webkit-inner-spin-button,input[type=number]::-webkit-outer-spin-button{-webkit-appearance:none;margin:0}input[type=number]{-moz-appearance:textfield;text-align:center}input:focus,select:focus{outline:none;border-color:var(--accent-blue);box-shadow:0 0 0 2px #58a6ff33}.grid-2{display:grid;grid-template-columns:1fr 1fr;gap:1rem}.grid-3{display:grid;grid-template-columns:1fr 1fr 1fr;gap:1rem}.btn-primary{background-color:var(--accent-blue);color:#fff;border:none;padding:.75rem 1.5rem;border-radius:6px;font-weight:600;cursor:pointer;transition:var(--transition);font-size:1rem;width:100%;min-height:44px}.btn-primary:hover{background-color:var(--accent-hover);transform:translateY(-1px)}.tabs{display:flex;gap:.5rem;margin-bottom:1.5rem;border-bottom:1px solid var(--border-color);overflow-x:auto;padding-bottom:.5rem;-webkit-overflow-scrolling:touch;scrollbar-width:none}.tabs::-webkit-scrollbar{display:none}.tab{padding:.6rem 1rem;border:none;background:transparent;color:var(--text-secondary);font-weight:500;cursor:pointer;border-bottom:2px solid transparent;white-space:nowrap;transition:var(--transition);flex-shrink:0;font-size:.95rem}.tab.active{color:var(--accent-blue);border-bottom-color:var(--accent-blue)}.result-box{background-color:var(--input-bg);padding:1.25rem 1rem;border-radius:8px;text-align:center;margin-top:1.25rem}.result-value{font-size:clamp(1.75rem,7vw,2.5rem);font-weight:700;color:var(--accent-blue);margin:.5rem 0;word-break:break-word}.result-label{font-size:.85rem;color:var(--text-secondary);text-transform:uppercase;letter-spacing:.05em}.split-list{display:flex;flex-direction:column;gap:.75rem}.split-card{background-color:var(--input-bg);border:1px solid var(--border-color);border-radius:8px;padding:1rem}.split-card-header{display:flex;justify-content:space-between;align-items:center;margin-bottom:.75rem}.split-badge{font-size:.85rem;font-weight:600;color:var(--accent-blue);text-transform:uppercase;letter-spacing:.05em}.btn-remove-split{background-color:#ef44441a;color:#ef4444;border:1px solid rgba(239,68,68,.2);padding:.35rem .75rem;border-radius:6px;font-size:.85rem;font-weight:600;cursor:pointer;transition:var(--transition)}.btn-remove-split:hover{background-color:#ef4444;color:#fff}@media (max-width: 640px){.app-container{padding:1rem .75rem}.header{margin-bottom:1.25rem}.logo-section{font-size:1.25rem}.card{padding:1.25rem 1rem;border-radius:10px}.card-title{font-size:1.1rem}.grid-2,.grid-3{grid-template-columns:1fr;gap:.75rem}.oauth-buttons{flex-direction:column}}@keyframes fadeIn{0%{opacity:0;transform:translateY(10px)}to{opacity:1;transform:translateY(0)}}.animate-fade{animation:fadeIn .4s ease forwards}.auth-mock{text-align:center;margin-top:3rem;padding-top:2rem;border-top:1px solid var(--border-color)}.auth-mock.hidden{display:none!important}.oauth-buttons{display:flex;justify-content:center;gap:1rem;margin-top:1rem}.btn-oauth{display:flex;align-items:center;justify-content:center;gap:.5rem;padding:.6rem 1rem;border:1px solid var(--border-color);background-color:var(--panel-bg);color:var(--text-primary);border-radius:6px;cursor:pointer;transition:var(--transition);font-weight:500;min-height:44px}.btn-oauth:hover{background-color:var(--input-bg)}