.usatt-calc, .usatt-directory, .usatt-cat-list {
  --usatt-navy:#0B2A4A; --usatt-navy-dark:#071B30; --usatt-green:#0F9D58; --usatt-green-dark:#0C7A44;
  --usatt-amber:#F5A623; --usatt-bg:#F5F7FA; --usatt-card:#FFFFFF; --usatt-text:#1B2430;
  --usatt-muted:#5B6B7C; --usatt-border:#E2E8F0; --usatt-radius:12px;
  --usatt-shadow:0 2px 12px rgba(11,42,74,0.08);
  font-family:-apple-system,BlinkMacSystemFont,'Segoe UI',Roboto,Arial,sans-serif;
  color:var(--usatt-text); max-width:1100px; margin:0 auto;
}
.usatt-calc *, .usatt-directory *, .usatt-cat-list *{ box-sizing:border-box; }
.usatt-calc h2{ color:var(--usatt-navy); font-size:18px; margin:0 0 16px; }
.usatt-intro{ color:var(--usatt-muted); font-size:15.5px; margin-bottom:22px; }
.usatt-layout{ display:grid; grid-template-columns:1.15fr 1fr; gap:28px; align-items:start; margin-bottom:10px; }
.usatt-panel{ background:var(--usatt-card); border:1px solid var(--usatt-border); border-radius:var(--usatt-radius); padding:24px; box-shadow:var(--usatt-shadow); }
.usatt-field{ margin-bottom:14px; }
.usatt-field label{ display:block; font-size:13.5px; font-weight:700; margin-bottom:6px; color:var(--usatt-navy); }
.usatt-field input, .usatt-field select{ width:100%; padding:11px 13px; border:1.5px solid var(--usatt-border); border-radius:8px; font-size:14.5px; font-family:inherit; color:var(--usatt-text); background:#fff; }
.usatt-field input:focus, .usatt-field select:focus{ border-color:var(--usatt-green); outline:none; }
.usatt-hint{ font-size:11.5px; color:var(--usatt-muted); margin-top:3px; }
.usatt-calc .calc-btn{ width:100%; padding:14px; background:var(--usatt-green); color:#fff; border:0; border-radius:8px; font-weight:700; font-size:15.5px; cursor:pointer; margin-top:6px; }
.usatt-calc .calc-btn:hover{ background:var(--usatt-green-dark); }
.usatt-result{ background:var(--usatt-navy); color:#fff; border-radius:var(--usatt-radius); padding:24px; position:sticky; top:20px; }
.usatt-result h2{ color:#fff; font-size:15px; font-weight:600; margin-bottom:4px; }
.usatt-result-figure{ font-size:32px; font-weight:800; color:var(--usatt-amber); margin:6px 0 16px; word-break:break-word; }
.usatt-result-row{ display:flex; justify-content:space-between; gap:10px; padding:9px 0; border-bottom:1px solid rgba(255,255,255,.15); font-size:13.5px; }
.usatt-result-row span:first-child{ color:#C9D6E4; }
.usatt-result-row span:last-child{ font-weight:700; text-align:right; }
.usatt-ad-slot{ margin:26px 0; text-align:center; }
.usatt-ad-label{ font-size:11px; letter-spacing:1px; text-transform:uppercase; color:var(--usatt-muted); margin-bottom:6px; }
.usatt-ad-frame{ border:1px dashed #CBD5E0; border-radius:8px; padding:14px; min-height:70px; display:flex; align-items:center; justify-content:center; color:var(--usatt-muted); font-size:12.5px; }
.usatt-content{ margin-top:10px; }
.usatt-content h2{ font-size:19px; margin-top:1.4em; }
.usatt-formula-box{ background:#EFF6F1; border-left:4px solid var(--usatt-green); border-radius:0 8px 8px 0; padding:14px 16px; font-family:'Courier New',monospace; font-size:14px; margin:0 0 1.2em; overflow-x:auto; }
.usatt-example-box{ background:var(--usatt-card); border:1px solid var(--usatt-border); border-radius:10px; padding:16px 18px; margin:0 0 1.2em; font-size:14.5px; }
.usatt-disclaimer{ background:#FFF7E8; border:1px solid #F0DBA0; border-left:4px solid var(--usatt-amber); border-radius:0 8px 8px 0; padding:13px 16px; font-size:13px; color:#5C4A16; margin:20px 0; }
.usatt-faq-item{ border-bottom:1px solid var(--usatt-border); padding:14px 0; }
.usatt-faq-item h3{ font-size:15px; margin:0 0 6px; color:var(--usatt-navy); }
.usatt-faq-item p{ margin:0; color:var(--usatt-muted); font-size:14px; }
.usatt-related{ display:grid; grid-template-columns:repeat(2,1fr); gap:10px; margin-top:6px; }
.usatt-related a{ display:block; background:var(--usatt-card); border:1px solid var(--usatt-border); border-radius:10px; padding:12px 16px; font-size:13.5px; font-weight:700; color:var(--usatt-navy); text-decoration:none; }
.usatt-related a:hover{ border-color:var(--usatt-green); color:var(--usatt-green-dark); }

/* Directory / category listing (used on the All Calculators and category pages) */
.usatt-directory{ }
.usatt-cat-block{ margin-bottom:30px; }
.usatt-cat-block h2{ font-size:20px; color:var(--usatt-navy); border-bottom:2px solid var(--usatt-border); padding-bottom:8px; margin-bottom:14px; }
.usatt-cat-grid{ display:grid; grid-template-columns:repeat(3,1fr); gap:12px; }
.usatt-cat-grid a{ display:block; background:var(--usatt-card); border:1px solid var(--usatt-border); border-radius:10px; padding:14px 16px; font-size:14px; font-weight:700; color:var(--usatt-navy); text-decoration:none; }
.usatt-cat-grid a:hover{ border-color:var(--usatt-green); color:var(--usatt-green-dark); }

.usatt-back-to-top{ position:fixed; right:20px; bottom:20px; width:44px; height:44px; border-radius:50%; background:var(--usatt-amber); color:var(--usatt-navy-dark); display:flex; align-items:center; justify-content:center; font-weight:800; box-shadow:0 8px 20px rgba(0,0,0,.2); opacity:0; visibility:hidden; transition:.25s; z-index:998; border:none; cursor:pointer; font-size:16px; }
.usatt-back-to-top.show{ opacity:1; visibility:visible; }

@media (max-width:900px){
  .usatt-layout{ grid-template-columns:1fr; }
  .usatt-result{ position:static; }
  .usatt-cat-grid{ grid-template-columns:1fr 1fr; }
}
@media (max-width:520px){
  .usatt-cat-grid{ grid-template-columns:1fr; }
  .usatt-result-figure{ font-size:26px; }
}