:root{
  --paper:#F5EFE3;--ink:#101418;--emerald:#0A5C4A;--marigold:#FFB81C;--coral:#FF6B4A;
  --cream:#FFFBF2;--muted:#5A5348;--soft:#E3EFE9;--line:#E5DCCB;
}
*{box-sizing:border-box}
html{-webkit-text-size-adjust:100%}
body{margin:0;background:var(--paper);color:var(--ink);font-family:'DM Sans',system-ui,-apple-system,Segoe UI,sans-serif;line-height:1.55}
a{color:inherit;text-decoration:none}
h1,h2,h3,.display{font-family:'Bricolage Grotesque','DM Sans',system-ui,sans-serif;letter-spacing:-0.03em;margin:0}
.wrap{max-width:1240px;margin:0 auto;padding:0 24px}

/* header / footer */
.site-header{display:flex;flex-wrap:wrap;align-items:center;justify-content:space-between;gap:16px;padding:20px 0}
.logo{display:flex;align-items:center;gap:10px;font-family:'Bricolage Grotesque',sans-serif;font-weight:800;font-size:22px;letter-spacing:-0.02em}
.logo-dot{width:34px;height:34px;border-radius:50%;background:var(--ink);display:flex;align-items:center;justify-content:center}
.logo-dot i{width:12px;height:12px;border-radius:50%;background:var(--marigold)}
.nav{display:flex;flex-wrap:wrap;gap:8px;align-items:center;font-weight:500;font-size:15px}
.nav a{padding:10px 16px;border-radius:999px}
.nav a.on{background:var(--marigold);font-weight:700}
.site-footer{background:var(--ink);color:#D8CFBD;margin-top:72px}
.site-footer .wrap{padding-top:36px;padding-bottom:36px;display:flex;flex-wrap:wrap;gap:24px;justify-content:space-between;font-size:14px;font-weight:500}
.site-footer .logo{color:var(--marigold)}
.site-footer nav{display:flex;flex-wrap:wrap;gap:22px}

/* page head */
.crumbs{font-size:14px;color:var(--muted)}
.page-head{padding:8px 0 24px;display:flex;flex-direction:column;gap:14px}
.page-head h1{font-weight:800;font-size:clamp(34px,5vw,58px);line-height:1.04}
.lede{font-size:19px;color:var(--muted);max-width:760px;margin:0}
.pill{align-self:flex-start;padding:7px 14px;border-radius:999px;background:var(--cream);border:1.5px solid var(--ink);font-size:13px;font-weight:600}

/* tool layout */
.tool{display:flex;flex-wrap:wrap;gap:28px;align-items:flex-start}
.panel{flex:1 1 520px;min-width:0;background:var(--cream);border:2px solid var(--ink);border-radius:26px;padding:28px;box-shadow:8px 8px 0 var(--ink)}
.preview-col{flex:1 1 440px;min-width:0}
.grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(200px,1fr));gap:14px}
.field{display:flex;flex-direction:column;gap:6px}
.field.wide{grid-column:1/-1}
label,.lbl{font-size:13px;font-weight:700}
input,select,textarea{font:inherit;color:var(--ink);padding:12px 14px;border:2px solid var(--ink);border-radius:12px;background:#fff;width:100%}
textarea{resize:vertical;min-height:70px}
input:focus,select:focus,textarea:focus{outline:3px solid var(--marigold);outline-offset:1px}
input.bad{border-color:var(--coral);background:#FFF1EC}
.hint{font-size:12px;color:var(--muted)}
.hint.err{color:#B3361B;font-weight:600}
h2.sec{font-size:20px;font-weight:800;margin:22px 0 10px;padding-top:18px;border-top:2px solid var(--ink)}
.items{display:flex;flex-direction:column;gap:10px}
.item{display:grid;grid-template-columns:3fr 1fr 1.4fr 1.2fr auto;gap:8px;align-items:center}
.item-head{font-size:12px;font-weight:700;color:var(--muted)}
.item .x{border:2px solid var(--ink);background:#fff;border-radius:10px;width:42px;height:44px;font-size:18px;cursor:pointer}
.item .x:hover{background:var(--coral)}
.btn{font:inherit;font-weight:700;cursor:pointer;border-radius:14px;padding:14px 22px;border:2px solid var(--ink);background:#fff;color:var(--ink)}
.btn.primary{background:var(--emerald);color:#fff;box-shadow:4px 4px 0 var(--ink)}
.btn.primary:hover{transform:translate(-1px,-1px)}
.btn.dashed{border-style:dashed;padding:10px 16px;font-size:14px}
.actions{display:flex;flex-wrap:wrap;gap:12px;margin-top:22px}
.note{font-size:13px;color:var(--muted);margin-top:12px}

/* the invoice paper */
.paper{background:#fff;border:2px solid var(--ink);border-radius:22px;padding:30px;box-shadow:8px 8px 0 var(--marigold);font-size:14px}
.paper-top{display:flex;justify-content:space-between;gap:16px;align-items:flex-start;flex-wrap:wrap}
.paper h3{font-size:26px;font-weight:800}
.paper .meta{text-align:right;font-size:13px;color:var(--muted)}
.paper .meta b{color:var(--ink)}
.parties{display:grid;grid-template-columns:1fr 1fr;gap:18px;margin:20px 0}
.parties small{display:block;font-weight:700;color:var(--muted);text-transform:uppercase;letter-spacing:.05em;font-size:11px;margin-bottom:4px}
.parties div{white-space:pre-line;overflow-wrap:anywhere}
.ptable{width:100%;border-collapse:collapse;margin-top:6px}
.ptable th{font-size:11px;text-transform:uppercase;letter-spacing:.05em;color:var(--muted);text-align:right;padding:8px 6px;border-bottom:2px solid var(--ink)}
.ptable th:first-child,.ptable td:first-child{text-align:left}
.ptable td{padding:9px 6px;text-align:right;border-bottom:1px solid var(--line);vertical-align:top;overflow-wrap:anywhere}
.totals{margin:16px 0 0 auto;max-width:300px;display:flex;flex-direction:column;gap:6px}
.totals div{display:flex;justify-content:space-between}
.totals .grand{margin-top:6px;padding:12px 14px;border-radius:12px;background:var(--emerald);color:#fff;font-family:'Bricolage Grotesque',sans-serif;font-weight:800;font-size:20px}
.paper .foot{margin-top:18px;color:var(--muted);font-size:12px;white-space:pre-line}
.empty{color:#8A8272}

/* content below tool */
.ad{display:flex;align-items:center;justify-content:center;min-height:90px;border:1.5px dashed #A79F8E;border-radius:14px;color:#6B6455;font-size:14px;margin:28px 0}
.article{max-width:880px;margin:0 auto;display:flex;flex-direction:column;gap:48px;padding-top:32px}
.article h2{font-weight:800;font-size:32px;line-height:1.1}
.answer{font-size:19px;padding-left:18px;border-left:6px solid var(--marigold);margin:12px 0}
.example{background:var(--soft);border:2px solid var(--ink);border-radius:20px;padding:22px;display:flex;flex-direction:column;gap:8px;margin-top:12px}
.example div{display:flex;justify-content:space-between}
.example .t{border-top:2px solid var(--ink);padding-top:8px;font-weight:700}
details{background:#fff;border:2px solid var(--ink);border-radius:14px;padding:16px 20px;margin-top:10px}
summary{font-weight:700;cursor:pointer}
details p{margin:8px 0 0;color:var(--muted)}
.mistake{padding:14px 18px;background:var(--cream);border:2px solid var(--ink);border-left:10px solid var(--coral);border-radius:14px;margin-top:10px}
.todo{background:#FFF4D6;border:1.5px dashed #B88400;border-radius:8px;padding:2px 6px;font-size:.95em}
.note-box{display:flex;flex-wrap:wrap;gap:20px}
.note-box>div{flex:1 1 300px;border-radius:20px;padding:22px;border:2px solid var(--ink)}
.note-box .rev{background:var(--emerald);color:#fff}
.note-box .src{background:var(--marigold)}

@media (max-width:640px){
  .item{grid-template-columns:1fr 1fr;}
  .item .desc{grid-column:1/-1}
  .item-head{display:none}
  .parties{grid-template-columns:1fr}
  .panel{padding:20px}
}

/* print: only the invoice paper */
@media print{
  body{background:#fff}
  .site-header,.site-footer,.page-head,.panel,.ad,.article,.crumbs,.preview-label,.no-print{display:none!important}
  .wrap{max-width:none;padding:0}
  .tool,.preview-col{display:block}
  .paper{border:none;box-shadow:none;border-radius:0;padding:0}
  @page{margin:14mm}
}

/* calculators (shared) */
.seg{display:flex;gap:8px;padding:6px;background:var(--line);border-radius:14px}
.seg button{flex:1;font:inherit;font-weight:700;padding:12px;border:0;border-radius:10px;background:transparent;color:var(--muted);cursor:pointer}
.seg button[aria-pressed=true]{background:var(--ink);color:var(--paper)}
.big{font-family:'Bricolage Grotesque',sans-serif;font-weight:800;font-size:clamp(24px,4vw,32px)}
.res{display:flex;flex-wrap:wrap;gap:12px;margin-top:18px}
.res>div{flex:1 1 150px;padding:16px;border:2px solid var(--ink);border-radius:16px}
.res .a{background:var(--soft)}.res .b{background:var(--marigold)}.res .c{background:var(--emerald);color:#fff}
.res small{display:block;font-weight:700;font-size:13px}
.formula{margin-top:16px;padding:14px 16px;background:#fff;border:2px dashed var(--ink);border-radius:14px;font-size:15px;overflow-wrap:anywhere}
.words-out{margin-top:18px;padding:20px;background:var(--soft);border:2px solid var(--ink);border-radius:16px;font-family:'Bricolage Grotesque',sans-serif;font-weight:700;font-size:22px;line-height:1.35;overflow-wrap:anywhere}
.words-out.empty{color:#8A8272;font-weight:500}
.rules{margin:10px 0 0;padding-left:20px;color:var(--muted)}
.checkrow{display:flex;gap:10px;align-items:center;font-weight:600}
.checkrow input{width:auto}
.hub{display:grid;grid-template-columns:repeat(auto-fit,minmax(260px,1fr));gap:20px}