.btuc-wrap{max-width:560px;margin:0 auto;font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,sans-serif;color:#1a1a1a}
.btuc-header{display:flex;align-items:center;gap:12px;margin-bottom:20px}
.btuc-icon{font-size:34px;line-height:1}
.btuc-title{font-size:22px!important;font-weight:600!important;margin:0 0 3px!important;padding:0!important;border:none!important;color:#1a1a1a!important}
.btuc-sub{font-size:13px;color:#666;margin:0}
.btuc-mode-toggle{display:flex;border:1.5px solid #d0d0d0;border-radius:10px;overflow:hidden;margin-bottom:16px}
.btuc-mbtn{flex:1;padding:10px;font-size:14px;font-weight:500;border:none;border-right:1px solid #d0d0d0;background:#fff;color:#555;cursor:pointer;transition:background .13s}
.btuc-mbtn:last-child{border-right:none}
.btuc-mbtn.act{background:#dbeafe;color:#1D4ED8;font-weight:700}
.btuc-grid{display:grid;grid-template-columns:1fr 1fr;gap:12px;margin-bottom:4px}
@media(max-width:440px){.btuc-grid{grid-template-columns:1fr}}
.btuc-lbl{display:block;font-size:13px;font-weight:500;color:#555;margin-bottom:5px}
.btuc-unit-row{display:flex;gap:8px}
.btuc-iw{flex:2;position:relative}
.btuc-iw input{width:100%;box-sizing:border-box;padding:9px 44px 9px 12px;border:1px solid #d0d0d0;border-radius:8px;font-size:14px;color:#1a1a1a;background:#fff;outline:none;transition:border-color .15s;-moz-appearance:textfield}
.btuc-iw input::-webkit-inner-spin-button,.btuc-iw input::-webkit-outer-spin-button{-webkit-appearance:none}
.btuc-iw input:focus{border-color:#1D4ED8;box-shadow:0 0 0 3px rgba(29,78,216,.1)}
.btuc-suf{position:absolute;right:8px;top:50%;transform:translateY(-50%);font-size:11px;color:#999;pointer-events:none;white-space:nowrap}
.btuc-sel,.btuc-sel2{box-sizing:border-box;padding:9px 10px;border:1px solid #d0d0d0;border-radius:8px;font-size:12px;color:#1a1a1a;background:#fff;outline:none;cursor:pointer;font-family:inherit;appearance:none;-webkit-appearance:none}
.btuc-sel{flex:1}
.btuc-sel2{width:100%}
.btuc-sel:focus,.btuc-sel2:focus{border-color:#1D4ED8}
/* Result */
.btuc-result-card{background:linear-gradient(135deg,#1D4ED8,#1e3a8a);border-radius:12px;padding:18px 22px;color:#fff;margin-top:12px;text-align:center;animation:btuc-in .22s ease}
@keyframes btuc-in{from{opacity:0;transform:translateY(5px)}to{opacity:1;transform:translateY(0)}}
.btuc-res-main{font-size:44px;font-weight:800;font-family:monospace;margin-bottom:4px}
.btuc-res-unit{font-size:15px;opacity:.8;margin-bottom:8px}
.btuc-res-extras{display:grid;grid-template-columns:repeat(3,1fr);gap:8px;border-top:1px solid rgba(255,255,255,.2);padding-top:10px}
.btuc-extra{text-align:center}
.btuc-extra-val{font-size:14px;font-weight:700;font-family:monospace}
.btuc-extra-lbl{font-size:11px;opacity:.65;margin-top:2px}
.btuc-ac-guide{background:#f0f9ff;border:1px solid #bae6fd;border-radius:10px;padding:12px 16px;margin-top:10px}
.btuc-ac-title{font-size:12px;font-weight:700;color:#0369A1;text-transform:uppercase;letter-spacing:.4px;margin-bottom:8px}
.btuc-ac-row{display:flex;justify-content:space-between;font-size:13px;padding:4px 0;border-bottom:1px solid #e0f2fe}
.btuc-ac-row:last-child{border-bottom:none}
.btuc-ac-row.recommended{background:#dbeafe;border-radius:5px;padding:5px 8px;font-weight:700;color:#1D4ED8}