/* ============================================================
   Calcuo.it — design system
   Signature idea: every calculation prints like an official
   Italian receipt/modulo — dashed tear line, monospace figures,
   a small protocollo stamp with timestamp. Navy + carta (paper)
   + timbro red, used sparingly.
   System fonts only — no webfont requests (LCP / CLS).
   ============================================================ */

:root{
  --navy: #16324F;
  --navy-ink: #0E2438;
  --paper: #F6F4EF;
  --paper-line: #E4E0D6;
  --card: #FFFFFF;
  --text: #1C1E22;
  --text-muted: #55606B;
  --stamp: #B23A2E;
  --stamp-dark: #8E2C22;
  --ok: #2F6F5E;
  --focus: #1461C9;

  --font-display: Georgia, "Times New Roman", "Noto Serif", serif;
  --font-body: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --font-mono: "SF Mono", "SFMono-Regular", Consolas, "Liberation Mono", Menlo, "Courier New", monospace;

  --radius: 3px;
  --container: 1080px;
}

*,*::before,*::after{ box-sizing: border-box; }
html{ -webkit-text-size-adjust: 100%; }
body{
  margin:0;
  background: var(--paper);
  color: var(--text);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.55;
}
img{ max-width:100%; display:block; }
a{ color: var(--navy); }
a:hover{ color: var(--stamp); }

@media (prefers-reduced-motion: reduce){
  *,*::before,*::after{ animation-duration: 0.001ms !important; animation-iteration-count: 1 !important; transition-duration: 0.001ms !important; scroll-behavior: auto !important; }
}

:focus-visible{
  outline: 3px solid var(--focus);
  outline-offset: 2px;
}

.skip-link{
  position:absolute; left:-999px; top:auto;
  background: var(--navy); color:#fff; padding: 10px 16px;
  z-index: 999; border-radius: var(--radius);
}
.skip-link:focus{ left: 12px; top: 12px; }

.wrap{ max-width: var(--container); margin: 0 auto; padding: 0 20px; }

/* ---------- Header ---------- */
.site-header{
  background: var(--navy);
  color: #fff;
  border-bottom: 4px solid var(--stamp);
}
.site-header .wrap{
  display:flex; align-items:center; justify-content:space-between;
  min-height: 64px;
}
.brand{
  font-family: var(--font-display);
  font-size: 1.4rem;
  font-weight: 700;
  color:#fff;
  text-decoration:none;
  letter-spacing: 0.2px;
}
.brand:hover{ color:#fff; opacity:0.9; }
.brand .dot{ color: var(--stamp); }
.main-nav{ display:flex; gap: 4px; }
.main-nav a{
  color: #EAF0F6;
  text-decoration:none;
  font-size: 0.95rem;
  padding: 10px 12px;
  border-radius: var(--radius);
}
.main-nav a:hover{ background: rgba(255,255,255,0.08); color:#fff; }
.nav-toggle{ display:none; }

@media (max-width: 720px){
  .main-nav{ display:none; }
}

/* ---------- Breadcrumb ---------- */
.breadcrumb{
  font-size: 0.85rem;
  color: var(--text-muted);
  padding: 14px 0 0;
}
.breadcrumb a{ color: var(--text-muted); text-decoration: underline; }
.breadcrumb a:hover{ color: var(--stamp); }

/* ---------- Hero / tool head ---------- */
.tool-head{ padding: 22px 0 10px; }
.eyebrow{
  display:inline-block;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--stamp-dark);
  background: rgba(178,58,46,0.08);
  border: 1px solid rgba(178,58,46,0.25);
  padding: 3px 8px;
  border-radius: var(--radius);
  margin-bottom: 10px;
}
h1{
  font-family: var(--font-display);
  font-size: clamp(1.7rem, 3.4vw, 2.5rem);
  line-height:1.15;
  margin: 0 0 10px;
  color: var(--navy-ink);
}
.tool-sub{
  color: var(--text-muted);
  font-size: 1.05rem;
  max-width: 62ch;
  margin: 0 0 6px;
}

/* ---------- Calculator card ---------- */
.calc-card{
  background: var(--card);
  border: 1px solid var(--paper-line);
  border-radius: 6px;
  box-shadow: 0 1px 2px rgba(20,20,30,0.04);
  padding: 22px;
  margin: 20px 0 28px;
}
.calc-tabs{
  display:flex; flex-wrap:wrap; gap: 6px;
  border-bottom: 1px solid var(--paper-line);
  margin-bottom: 18px;
  padding-bottom: 12px;
}
.calc-tab{
  font-family: var(--font-body);
  font-size: 0.88rem;
  background: var(--paper);
  border: 1px solid var(--paper-line);
  color: var(--text);
  padding: 7px 12px;
  border-radius: 999px;
  cursor:pointer;
}
.calc-tab[aria-selected="true"]{
  background: var(--navy);
  border-color: var(--navy);
  color: #fff;
}
.calc-panel{ display:none; }
.calc-panel.active{ display:block; }

.field-row{
  display:flex; flex-wrap:wrap; gap: 14px;
  margin-bottom: 14px;
}
.field{ flex: 1 1 180px; min-width: 140px; }
.field label{
  display:block; font-size: 0.85rem; font-weight:600;
  margin-bottom: 5px; color: var(--navy-ink);
}
.field input, .field select{
  width:100%;
  font-family: var(--font-mono);
  font-size: 1.05rem;
  padding: 10px 12px;
  border: 1.5px solid var(--paper-line);
  border-radius: var(--radius);
  background:#fff;
  color: var(--text);
}
.field input:focus, .field select:focus{ border-color: var(--focus); }
.field .hint{ font-size:0.78rem; color: var(--text-muted); margin-top:4px; }

.btn{
  font-family: var(--font-body);
  font-weight: 700;
  font-size: 0.98rem;
  background: var(--navy);
  color: #fff;
  border: none;
  padding: 11px 20px;
  border-radius: var(--radius);
  cursor: pointer;
}
.btn:hover{ background: var(--navy-ink); }
.btn.secondary{
  background: transparent;
  color: var(--navy);
  border: 1.5px solid var(--navy);
}
.btn.secondary:hover{ background: rgba(22,50,79,0.06); }

/* ---------- Receipt-style result ---------- */
.receipt{
  margin-top: 18px;
  background: var(--paper);
  border: 1px dashed #B7AF9E;
  border-radius: var(--radius);
  padding: 18px 20px;
  font-family: var(--font-mono);
  display:none;
}
.receipt.show{ display:block; }
.receipt-head{
  display:flex; justify-content:space-between; align-items:baseline;
  font-size: 0.72rem; letter-spacing:0.05em; text-transform:uppercase;
  color: var(--text-muted);
  border-bottom: 1px dashed #B7AF9E;
  padding-bottom: 8px; margin-bottom: 10px;
}
.receipt-row{
  display:flex; justify-content:space-between; gap: 12px;
  padding: 4px 0;
  font-size: 0.95rem;
}
.receipt-row.total{
  border-top: 1px dashed #B7AF9E;
  margin-top: 8px; padding-top: 10px;
  font-size: 1.25rem; font-weight: 700;
  color: var(--navy-ink);
}
.receipt-row.total .stamp-value{ color: var(--stamp-dark); }
[aria-live="polite"]{ }

/* ---------- Content sections ---------- */
.content{ padding: 6px 0 40px; max-width: 72ch; }
.content h2{
  font-family: var(--font-display);
  color: var(--navy-ink);
  font-size: 1.4rem;
  margin: 34px 0 12px;
}
.content h3{ font-size: 1.1rem; color: var(--navy-ink); margin: 22px 0 8px; }
.content p{ margin: 0 0 14px; }
.content ul, .content ol{ margin: 0 0 14px; padding-left: 22px; }
.content li{ margin-bottom: 6px; }
.content .formula{
  font-family: var(--font-mono);
  background: #fff;
  border: 1px solid var(--paper-line);
  border-left: 3px solid var(--stamp);
  padding: 10px 14px;
  border-radius: var(--radius);
  display:inline-block;
  margin: 4px 0 14px;
}

.faq-item{
  border-bottom: 1px solid var(--paper-line);
  padding: 14px 0;
}
.faq-item summary{
  font-weight: 700; cursor:pointer; color: var(--navy-ink);
  list-style: none;
  display:flex; align-items:center; gap:8px;
}
.faq-item summary::-webkit-details-marker{ display:none; }
.faq-item summary::before{
  content: "+"; color: var(--stamp); font-size:1.2rem; width:16px;
}
.faq-item[open] summary::before{ content: "–"; }
.faq-item p{ margin: 10px 0 0 24px; color: var(--text-muted); }

/* ---------- Related tools ---------- */
.related{ padding: 10px 0 40px; }
.related h2{ font-family: var(--font-display); font-size:1.3rem; color: var(--navy-ink); }
.related-grid{
  display:grid; grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
  gap: 12px;
}
.related-card{
  display:block; background: var(--card); border: 1px solid var(--paper-line);
  border-radius: var(--radius); padding: 14px 16px; text-decoration:none;
}
.related-card:hover{ border-color: var(--navy); }
.related-card .rc-title{ color: var(--navy-ink); font-weight:700; font-size:0.95rem; }
.related-card .rc-sub{ color: var(--text-muted); font-size:0.8rem; margin-top:2px; }

/* ---------- Homepage tool grid ---------- */
.tool-grid{
  display:grid; grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
  gap: 14px; padding: 10px 0 40px;
}
.tool-card{
  background: var(--card); border: 1px solid var(--paper-line);
  border-radius: 6px; padding: 18px; text-decoration:none;
  transition: none;
}
.tool-card:hover{ border-color: var(--navy); box-shadow: 0 2px 6px rgba(20,20,30,0.06); }
.tool-card .tc-title{ font-family: var(--font-display); font-size:1.08rem; color: var(--navy-ink); margin-bottom:4px; }
.tool-card .tc-desc{ font-size: 0.86rem; color: var(--text-muted); }

.section-title{
  font-family: var(--font-display);
  font-size: clamp(1.5rem, 3vw, 2rem);
  color: var(--navy-ink);
  margin: 30px 0 4px;
}
.section-lede{ color: var(--text-muted); max-width: 62ch; margin: 0 0 6px; }

/* ---------- Footer ---------- */
.site-footer{
  background: var(--navy-ink);
  color: #C9D3DC;
  margin-top: 40px;
}
.site-footer .wrap{ padding: 32px 20px; }
.footer-cols{
  display:grid; grid-template-columns: repeat(auto-fit, minmax(160px,1fr));
  gap: 20px; margin-bottom: 20px;
}
.footer-cols h4{ color:#fff; font-size:0.85rem; margin: 0 0 10px; }
.footer-cols a{ display:block; color:#C9D3DC; text-decoration:none; font-size:0.86rem; padding:3px 0; }
.footer-cols a:hover{ color:#fff; }
.footer-bottom{
  border-top: 1px solid rgba(255,255,255,0.12);
  padding-top: 16px; font-size: 0.78rem; color: #90A0AE;
  display:flex; flex-wrap:wrap; gap: 10px 20px; justify-content:space-between;
}

/* ---------- Legal pages ---------- */
.legal .content h2{ margin-top: 28px; }

/* ---------- Utility ---------- */
.visually-hidden{
  position:absolute; width:1px; height:1px; overflow:hidden;
  clip: rect(0,0,0,0); white-space:nowrap; border:0; padding:0; margin:-1px;
}