.circum-wrap{margin-bottom:2rem;}
.circum-split{display:flex;flex-direction:column;gap:1.25rem;background:#fff;border:1px solid #e2e8f0;border-radius:16px;box-shadow:0 4px 24px rgba(0,0,0,0.06);padding:1.25rem;}
.circum-left{display:flex;flex-direction:column;gap:1rem;}
.circum-switch{display:flex;gap:0;background:#f1f5f9;border-radius:10px;padding:4px;}
.circum-switch-btn{flex:1;padding:0.625rem 1rem;font-size:0.9375rem;font-weight:600;color:#64748b;background:transparent;border:none;border-radius:8px;cursor:pointer;transition:color 0.2s,background 0.2s;-webkit-tap-highlight-color:transparent;}
.circum-switch-btn:hover{color:#0f172a;}
.circum-switch-btn.is-active{background:#fff;color:#2563eb;box-shadow:0 1px 4px rgba(0,0,0,0.08);}
.circum-field{display:flex;flex-wrap:wrap;align-items:center;gap:0.5rem;}
.circum-label{flex:0 0 100%;font-size:0.8125rem;font-weight:600;color:#64748b;}
.circum-input{flex:1;min-width:0;padding:0.875rem 1rem;font-size:1.125rem;font-variant-numeric:tabular-nums;border:2px solid #e2e8f0;border-radius:10px;background:#fff;transition:border-color 0.2s,box-shadow 0.2s;-webkit-appearance:none;appearance:none;}
.circum-input:focus{outline:none;border-color:#2563eb;box-shadow:0 0 0 3px rgba(37,99,235,0.12);}
.circum-input::placeholder{color:#94a3b8;}
.circum-unit{font-size:0.875rem;color:#64748b;}
.circum-right{padding:1rem;background:#f8fafc;border-radius:12px;border:1px solid #e2e8f0;}
.circum-out-label{display:block;font-size:0.75rem;font-weight:600;color:#64748b;text-transform:uppercase;letter-spacing:0.04em;margin-bottom:0.375rem;}
.circum-out-value{display:block;font-size:1.5rem;font-weight:700;color:#0f172a;font-variant-numeric:tabular-nums;line-height:1.2;}
.circum-formula{font-size:0.8125rem;color:#64748b;margin:0.5rem 0 0;line-height:1.4;}
@media (min-width:600px){.circum-split{flex-direction:row;align-items:stretch;padding:1.5rem;}.circum-left{flex:0 0 240px;}.circum-right{flex:1;min-width:0;display:flex;flex-direction:column;justify-content:center;}}
@media (min-width:768px){.circum-split{padding:1.75rem;gap:1.5rem;}.circum-left{flex:0 0 260px;}.circum-input{font-size:1.25rem;padding:1rem 1.25rem;}.circum-out-value{font-size:1.75rem;}.circum-formula{font-size:0.875rem;}}
@media (min-width:900px){.circum-out-value{font-size:2rem;}}