/* ============================================================
   GST Calculator Pro — gstcalculatorpro.com
   Design system: paper / ink / teal / saffron, receipt motif
   ============================================================ */
:root{
  --paper:#F7F6F1;
  --card:#FFFFFF;
  --ink:#16232A;
  --muted:#5B6B72;
  --teal:#0E6E66;
  --teal-dark:#0A524C;
  --teal-soft:#E3F0EE;
  --saffron:#E9A115;
  --saffron-soft:#FBEFD6;
  --line:#DDD9CD;
  --danger:#B4372E;
  --ok:#0B7A45;
  --radius:14px;
  --shadow:0 1px 2px rgba(22,35,42,.06),0 8px 24px rgba(22,35,42,.07);
  --font-body:"IBM Plex Sans",system-ui,-apple-system,"Segoe UI",Roboto,sans-serif;
  --font-display:"Archivo",var(--font-body);
  --font-mono:"IBM Plex Mono",ui-monospace,"SF Mono",Menlo,Consolas,monospace;
}
*{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth}
@media (prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  *,*::before,*::after{animation:none!important;transition:none!important}
}
body{
  font-family:var(--font-body);
  background:var(--paper);
  color:var(--ink);
  line-height:1.6;
  -webkit-font-smoothing:antialiased;
  font-size:16px;
}
img,svg{max-width:100%;display:block}
a{color:var(--teal);text-decoration:none}
a:hover{text-decoration:underline}
:focus-visible{outline:3px solid var(--saffron);outline-offset:2px;border-radius:4px}
.container{max-width:1080px;margin:0 auto;padding:0 20px}
.visually-hidden{position:absolute;width:1px;height:1px;overflow:hidden;clip:rect(0 0 0 0);white-space:nowrap}

/* ---------- Header ---------- */
.site-header{
  position:sticky;top:0;z-index:50;
  background:rgba(247,246,241,.92);
  backdrop-filter:blur(8px);
  border-bottom:1px solid var(--line);
}
.header-inner{display:flex;align-items:center;gap:16px;height:64px}
.brand{display:flex;align-items:center;gap:10px;font-family:var(--font-display);font-weight:800;font-size:1.12rem;color:var(--ink);letter-spacing:-.01em;white-space:nowrap}
.brand:hover{text-decoration:none}
.brand-mark{
  width:34px;height:34px;border-radius:9px;flex:0 0 auto;
  background:var(--teal);color:#fff;
  display:flex;align-items:center;justify-content:center;
  font-family:var(--font-mono);font-weight:600;font-size:1.05rem;
}
.brand-mark span{transform:translateY(-1px)}
.brand em{font-style:normal;color:var(--teal)}
.main-nav{margin-left:auto;display:flex;align-items:center;gap:4px}
.main-nav a{padding:8px 12px;border-radius:8px;color:var(--ink);font-weight:500;font-size:.95rem}
.main-nav a:hover{background:var(--teal-soft);text-decoration:none}
.main-nav a[aria-current="page"]{background:var(--teal);color:#fff}
.lang-switch{
  margin-left:8px;display:flex;border:1.5px solid var(--line);border-radius:999px;overflow:hidden;background:#fff;
}
.lang-switch button{
  border:0;background:transparent;padding:6px 13px;cursor:pointer;
  font-family:var(--font-body);font-weight:600;font-size:.85rem;color:var(--muted);
}
.lang-switch button[aria-pressed="true"]{background:var(--ink);color:#fff}
.nav-toggle{display:none;margin-left:auto;border:1.5px solid var(--line);background:#fff;border-radius:8px;padding:8px 10px;cursor:pointer;font-size:1rem;line-height:1}

/* ---------- Hero ---------- */
.hero{padding:44px 0 8px}
.hero .eyebrow{
  display:inline-block;font-family:var(--font-mono);font-size:.78rem;letter-spacing:.08em;
  text-transform:uppercase;color:var(--teal);background:var(--teal-soft);
  padding:4px 10px;border-radius:999px;margin-bottom:14px;
}
.hero h1{
  font-family:var(--font-display);font-weight:800;letter-spacing:-.025em;
  font-size:clamp(1.9rem,4.6vw,3rem);line-height:1.12;max-width:21ch;
}
.hero .lede{margin-top:12px;max-width:62ch;color:var(--muted);font-size:1.06rem}

/* ---------- Calculator layout ---------- */
.calc-wrap{
  display:grid;grid-template-columns:1.1fr .9fr;gap:26px;
  margin:30px 0 10px;align-items:start;
}
.calc-card{
  background:var(--card);border:1px solid var(--line);border-radius:var(--radius);
  box-shadow:var(--shadow);padding:26px;
}
.calc-card h2{font-family:var(--font-display);font-size:1.15rem;font-weight:700;margin-bottom:18px;letter-spacing:-.01em}
.field{margin-bottom:16px}
.field label{display:block;font-weight:600;font-size:.9rem;margin-bottom:6px}
.field .hint{font-weight:400;color:var(--muted);font-size:.82rem}
input[type="number"],input[type="text"],input[type="email"],select,textarea{
  width:100%;padding:12px 14px;font:inherit;color:var(--ink);
  border:1.5px solid var(--line);border-radius:10px;background:#fff;
  font-family:var(--font-mono);font-size:1rem;
}
select,textarea,input[type="email"]{font-family:var(--font-body)}
input:focus,select:focus,textarea:focus{border-color:var(--teal);outline:none;box-shadow:0 0 0 3px var(--teal-soft)}
.input-prefix{position:relative}
.input-prefix input{padding-left:34px}
.input-prefix::before{
  content:"₹";position:absolute;left:13px;top:50%;transform:translateY(-50%);
  font-family:var(--font-mono);color:var(--muted);pointer-events:none;
}
.seg{display:flex;flex-wrap:wrap;gap:8px}
.seg input{position:absolute;opacity:0;pointer-events:none}
.seg label{
  cursor:pointer;padding:9px 15px;border:1.5px solid var(--line);border-radius:999px;
  font-family:var(--font-mono);font-size:.92rem;font-weight:500;background:#fff;user-select:none;
  margin:0;display:inline-block;
}
.seg input:checked + label{background:var(--ink);border-color:var(--ink);color:#fff}
.seg input:focus-visible + label{outline:3px solid var(--saffron);outline-offset:2px}
.row-2{display:grid;grid-template-columns:1fr 1fr;gap:14px}
.btn{
  display:inline-flex;align-items:center;justify-content:center;gap:8px;
  border:0;border-radius:10px;padding:13px 22px;cursor:pointer;
  font:inherit;font-weight:700;font-size:1rem;
  background:var(--teal);color:#fff;width:100%;
  transition:background .15s;
}
.btn:hover{background:var(--teal-dark)}
.btn-ghost{background:transparent;color:var(--teal);border:1.5px solid var(--teal);width:auto;padding:9px 16px;font-size:.9rem}
.btn-ghost:hover{background:var(--teal-soft)}
.btn-row{display:flex;gap:10px;flex-wrap:wrap;margin-top:6px}

/* ---------- Receipt (signature element) ---------- */
.receipt{
  background:#fff;border:1px solid var(--line);border-bottom:0;
  border-radius:6px 6px 0 0;box-shadow:var(--shadow);
  padding:22px 22px 14px;position:relative;
  font-family:var(--font-mono);
}
.receipt::before{
  content:"";position:absolute;left:14px;right:14px;top:10px;
  border-top:2px dashed var(--line);
}
.receipt-tear{
  height:14px;border:0;margin:0;box-shadow:var(--shadow);
  background:
    linear-gradient(-45deg,transparent 70%,#fff 71%) 0 0/14px 14px repeat-x,
    linear-gradient(45deg,transparent 70%,#fff 71%) 0 0/14px 14px repeat-x;
  filter:drop-shadow(0 3px 3px rgba(22,35,42,.08));
}
.receipt h3{
  font-family:var(--font-mono);font-weight:600;font-size:.8rem;
  letter-spacing:.14em;text-transform:uppercase;color:var(--muted);
  text-align:center;margin:8px 0 16px;
}
.receipt table{width:100%;border-collapse:collapse;font-size:.95rem}
.receipt td{padding:7px 0;vertical-align:top}
.receipt td:last-child{text-align:right;font-variant-numeric:tabular-nums;white-space:nowrap}
.receipt tr.rule td{border-top:1.5px dashed var(--line);padding-top:11px}
.receipt tr.total td{
  font-weight:700;font-size:1.28rem;color:var(--teal-dark);
  border-top:2px solid var(--ink);padding-top:12px;
}
.receipt .tag{color:var(--muted);font-size:.82rem}
.receipt .stamp{
  margin:14px auto 2px;text-align:center;font-size:.72rem;letter-spacing:.1em;
  text-transform:uppercase;color:var(--muted);
}
.receipt .neg{color:var(--danger)}
.receipt .pos{color:var(--ok)}

/* ---------- Tool grid ---------- */
.section{padding:44px 0}
.section-head{display:flex;align-items:baseline;justify-content:space-between;gap:16px;margin-bottom:22px;flex-wrap:wrap}
.section h2{font-family:var(--font-display);font-weight:800;font-size:clamp(1.35rem,3vw,1.8rem);letter-spacing:-.02em}
.section .sub{color:var(--muted);max-width:60ch}
.tool-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(240px,1fr));gap:14px;list-style:none}
.tool-card{
  display:block;background:var(--card);border:1px solid var(--line);border-radius:12px;
  padding:18px;color:var(--ink);height:100%;
  transition:transform .15s,border-color .15s,box-shadow .15s;
}
.tool-card:hover{text-decoration:none;transform:translateY(-2px);border-color:var(--teal);box-shadow:var(--shadow)}
.tool-card .t-ico{
  width:38px;height:38px;border-radius:9px;background:var(--saffron-soft);
  display:flex;align-items:center;justify-content:center;margin-bottom:12px;
  font-family:var(--font-mono);font-weight:600;color:var(--saffron);font-size:1.05rem;
}
.tool-card h3{font-size:1rem;font-weight:700;margin-bottom:4px;font-family:var(--font-display)}
.tool-card p{font-size:.86rem;color:var(--muted);line-height:1.5}

/* ---------- Content / SEO prose ---------- */
.prose{max-width:760px}
.prose h2{font-family:var(--font-display);font-weight:800;font-size:1.5rem;letter-spacing:-.02em;margin:36px 0 12px}
.prose h3{font-family:var(--font-display);font-weight:700;font-size:1.13rem;margin:26px 0 8px}
.prose p{margin:0 0 14px;color:#33424a}
.prose ul,.prose ol{margin:0 0 14px 22px;color:#33424a}
.prose li{margin-bottom:6px}
.prose .formula{
  font-family:var(--font-mono);background:var(--teal-soft);border-left:4px solid var(--teal);
  padding:12px 16px;border-radius:0 8px 8px 0;margin:14px 0;font-size:.93rem;overflow-x:auto;
}
.prose table{width:100%;border-collapse:collapse;margin:14px 0;font-size:.93rem;background:#fff;border:1px solid var(--line);border-radius:10px;overflow:hidden}
.prose th{background:var(--ink);color:#fff;text-align:left;padding:10px 12px;font-family:var(--font-display);font-weight:600;font-size:.86rem}
.prose td{padding:9px 12px;border-top:1px solid var(--line);font-variant-numeric:tabular-nums}
.prose tr:nth-child(even) td{background:#FAFAF6}

/* FAQ */
.faq details{
  background:#fff;border:1px solid var(--line);border-radius:10px;
  padding:0;margin-bottom:10px;overflow:hidden;
}
.faq summary{
  cursor:pointer;font-weight:600;padding:15px 18px;list-style:none;position:relative;padding-right:44px;
}
.faq summary::-webkit-details-marker{display:none}
.faq summary::after{
  content:"+";position:absolute;right:16px;top:50%;transform:translateY(-50%);
  font-family:var(--font-mono);font-size:1.2rem;color:var(--teal);
}
.faq details[open] summary::after{content:"–"}
.faq .faq-a{padding:0 18px 15px;color:#33424a}

/* Notice */
.notice{
  background:var(--saffron-soft);border:1px solid #EBD3A0;border-radius:10px;
  padding:13px 16px;font-size:.88rem;color:#6B4E12;margin:18px 0;
}

/* ---------- HSN table search ---------- */
.hsn-search{margin-bottom:14px}
.hsn-table-wrap{overflow-x:auto;border:1px solid var(--line);border-radius:12px;background:#fff}
.hsn-table{width:100%;border-collapse:collapse;font-size:.92rem;min-width:520px}
.hsn-table th{background:var(--ink);color:#fff;text-align:left;padding:11px 14px;font-size:.83rem;font-family:var(--font-display);position:sticky;top:0}
.hsn-table td{padding:10px 14px;border-top:1px solid var(--line)}
.hsn-table td:first-child{font-family:var(--font-mono);font-weight:600;color:var(--teal-dark);white-space:nowrap}
.hsn-table td:last-child{font-family:var(--font-mono);white-space:nowrap}
.hsn-table tr:hover td{background:var(--teal-soft)}
.hsn-count{font-size:.85rem;color:var(--muted);margin-top:8px}

/* ---------- Invoice line items ---------- */
.li-table{width:100%;border-collapse:collapse;font-size:.92rem}
.li-table th{text-align:left;font-size:.78rem;text-transform:uppercase;letter-spacing:.06em;color:var(--muted);padding:0 8px 6px 0;font-weight:600}
.li-table td{padding:0 8px 10px 0;vertical-align:middle}
.li-table input,.li-table select{padding:9px 10px;font-size:.92rem}
.li-remove{border:0;background:transparent;color:var(--danger);cursor:pointer;font-size:1.15rem;line-height:1;padding:6px}

/* ---------- Breadcrumb ---------- */
.crumbs{font-size:.85rem;color:var(--muted);padding:18px 0 0}
.crumbs ol{list-style:none;display:flex;flex-wrap:wrap;gap:6px}
.crumbs li+li::before{content:"›";margin-right:6px;color:var(--line)}

/* ---------- Footer ---------- */
.site-footer{background:var(--ink);color:#C7D2D8;margin-top:60px;padding:44px 0 26px}
.footer-grid{display:grid;grid-template-columns:1.4fr 1fr 1fr 1fr;gap:30px}
.site-footer h4{color:#fff;font-family:var(--font-display);font-size:.95rem;margin-bottom:12px;letter-spacing:.02em}
.site-footer ul{list-style:none}
.site-footer li{margin-bottom:8px}
.site-footer a{color:#C7D2D8;font-size:.9rem}
.site-footer a:hover{color:var(--saffron)}
.footer-about p{font-size:.9rem;line-height:1.65;margin-top:10px;max-width:34ch}
.footer-bottom{
  border-top:1px solid rgba(255,255,255,.14);margin-top:34px;padding-top:18px;
  display:flex;justify-content:space-between;gap:12px;flex-wrap:wrap;
  font-size:.83rem;color:#8FA0A8;
}
.footer-bottom .mono{font-family:var(--font-mono)}

/* ---------- Responsive ---------- */
@media (max-width:900px){
  .calc-wrap{grid-template-columns:1fr}
  .footer-grid{grid-template-columns:1fr 1fr}
}
@media (max-width:720px){
  .nav-toggle{display:block}
  .main-nav{
    display:none;position:absolute;top:64px;left:0;right:0;
    background:var(--paper);border-bottom:1px solid var(--line);
    flex-direction:column;align-items:stretch;padding:10px 20px 16px;gap:2px;
  }
  .main-nav.open{display:flex}
  .main-nav a{padding:12px 10px}
  .lang-switch{margin:10px 0 0}
  .row-2{grid-template-columns:1fr}
  .hero{padding-top:30px}
  .calc-card{padding:20px 16px}
  .receipt{padding:18px 16px 12px}
}
@media (max-width:480px){
  .footer-grid{grid-template-columns:1fr}
  body{font-size:15.5px}
}