:root{
  --brand: #0ea5e9;
  --text: inherit;
  --card: color-mix(in oklab, var(--brand) 1%, transparent);
  --border: color-mix(in oklab, currentColor 22%, transparent);
}
*{box-sizing:border-box}
html,body{height:100%}
html{font-size:16px}
body{margin:0;font:16px/1.55 system-ui,Segoe UI,Roboto,Arial,sans-serif;color:var(--text)}

.page{max-width:960px;margin:0 auto;padding:24px 16px}
.container{display:grid;gap:16px}
.centered{text-align:center}
.page-header{margin-bottom:16px}
.crumbs{opacity:.8;display:flex;gap:8px;align-items:center;font-size:.95rem}
.lead{opacity:.9;margin:6px 0 0}
.highlight-seo{text-align:center;background:color-mix(in oklab,var(--brand) 15%,transparent);padding:8px 12px;border-radius:8px;font-weight:500;margin-bottom:10px}

.card{border:1px solid var(--border);border-radius:14px;padding:14px;background:var(--card)}

.tabs{display:flex;gap:8px;align-items:center;justify-content:center}
.tab{border:1px solid var(--border);background:#fff0;border-radius:999px;padding:8px 14px;cursor:pointer}
.tab.active{background:color-mix(in oklab,var(--brand) 16%,transparent);border-color:color-mix(in oklab,var(--brand) 60%,transparent)}

.tabpane.hidden{display:none}

form{display:grid;gap:12px}
.field{display:grid;gap:6px}
.field input,.field select{border:1px solid var(--border);background:var(--card);border-radius:10px;padding:10px 12px;color:inherit;min-height:44px;font-size:16px}
.field.highlight input,.field.highlight select{border:2px solid var(--brand);background:color-mix(in oklab,var(--brand) 8%,transparent);font-weight:600}
.help{font-size:.9rem;opacity:.8}
.error{color:#d92d20;min-height:1.2em;font-size:.9rem}

.actions{display:flex;gap:10px;flex-wrap:wrap;justify-content:center}
.btn{border:1px solid var(--border);background:transparent;padding:12px 14px;border-radius:10px;cursor:pointer}
.btn.primary{background:var(--brand);color:#fff;border-color:var(--brand)}
.btn.ghost{opacity:.9}
@media (max-width:380px){.actions{flex-direction:column;align-items:stretch}.actions .btn{width:100%}}

.result-grid{display:grid;gap:12px;grid-template-columns:1fr;margin:6px 0 8px}
@media (min-width:680px){.result-grid{grid-template-columns:repeat(3,minmax(0,1fr))}}
.metric{text-align:center;padding:10px 12px;border:1px dashed var(--border);border-radius:12px;background:color-mix(in oklab,var(--brand) 4%,transparent)}
.metric-title{font-size:.95rem;opacity:.85;margin-bottom:4px}
.metric-value{font-size:clamp(22px,5vw,32px);font-weight:800}

.details{margin-top:8px}
.result-breakdown table{width:100%;border-collapse:collapse}
.result-breakdown td{padding:6px 0;border-bottom:1px dashed var(--border)}
.result-breakdown td:last-child{text-align:right}

.inner{margin-top:8px}

.adv-grid{display:grid;gap:12px;grid-template-columns:repeat(auto-fit,minmax(220px,1fr))}

.page-footer{display:flex;gap:12px;align-items:center;flex-wrap:wrap;justify-content:center;margin-top:8px}

@media (min-width:960px){.page{max-width:1000px}}

/* Back button */

.btn-back, a.btn-back {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: .85rem;
  font-weight: 600;
  text-decoration: none;
  padding: 8px 14px;
  border-radius: 12px;
  border: 1px solid #e2e8f0;
  background: #fff;
  color: #0f172a;
  cursor: pointer;
  transition: background .15s, border-color .15s, transform .12s;
  margin-bottom: 10px;
}
.btn-back:hover { transform: translateY(-1px); border-color: var(--calc-accent, #0ea5e9); background: color-mix(in srgb, var(--calc-accent, #0ea5e9) 5%, #fff); }
.btn-back svg { flex-shrink: 0; }
@media (prefers-color-scheme: dark){
  html:not([data-theme]) .btn-back { border-color: #1f2a37; background: #0f141b; color: #e6edf3; }
  html:not([data-theme]) .btn-back:hover { border-color: var(--calc-accent, #22c3f3); background: color-mix(in srgb, var(--calc-accent, #22c3f3) 5%, #0f141b); }
}
html[data-theme="dark"] .btn-back { border-color: #1f2a37 !important; background: #0f141b !important; color: #e6edf3 !important; }
html[data-theme="dark"] .btn-back:hover { border-color: var(--calc-accent, #22c3f3) !important; background: color-mix(in srgb, var(--calc-accent, #22c3f3) 5%, #0f141b) !important; }
html[data-theme="light"] .btn-back { border-color: #e2e8f0 !important; background: #fff !important; color: #0f172a !important; }
html[data-theme="light"] .btn-back:hover { border-color: var(--calc-accent, #0ea5e9) !important; background: color-mix(in srgb, var(--calc-accent, #0ea5e9) 5%, #fff) !important; }