:root{
  --green:#0b5d3b;
  --green-dark:#084229;
  --accent:#f5a623;
  --bg:#f4f7f5;
  --card:#ffffff;
  --text:#16261f;
  --muted:#5a6b62;
  --border:#dde6e0;
  --radius:14px;
  --shadow:0 6px 24px rgba(11,93,59,.08);
}
*{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth}
body{
  font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,"Noto Sans Tamil","Helvetica Neue",Arial,sans-serif;
  background:var(--bg);color:var(--text);line-height:1.6;
}
.wrap{max-width:920px;margin:0 auto;padding:0 18px}
header{
  background:linear-gradient(135deg,var(--green),var(--green-dark));
  color:#fff;padding:38px 0 30px;text-align:center;
}
header .badge{
  display:inline-block;background:rgba(255,255,255,.15);
  border:1px solid rgba(255,255,255,.3);padding:5px 14px;border-radius:999px;
  font-size:13px;font-weight:600;margin-bottom:14px;letter-spacing:.3px;
}
header h1{font-size:clamp(22px,4.5vw,32px);line-height:1.25;font-weight:800}
header .ta{font-size:clamp(15px,3vw,19px);font-weight:600;opacity:.95;margin-top:6px}
header p.sub{margin-top:10px;font-size:14px;opacity:.9}

main{padding:28px 0 60px}
.card{
  background:var(--card);border:1px solid var(--border);
  border-radius:var(--radius);box-shadow:var(--shadow);
  padding:24px;margin-bottom:24px;
}
h2{font-size:20px;margin-bottom:4px;color:var(--green-dark)}
h2 .ta{display:block;font-size:15px;color:var(--muted);font-weight:600}
h3{font-size:16px;margin:18px 0 8px;color:var(--green-dark)}

.calc-grid{display:flex;flex-direction:column;gap:14px;margin-top:16px}
label{font-weight:600;font-size:14px;display:block;margin-bottom:6px}
label .ta{color:var(--muted);font-weight:500}
.stepper{display:flex;align-items:stretch;gap:8px}
input[type=number]{
  flex:1;width:100%;min-width:0;padding:14px 16px;font-size:18px;text-align:center;
  border:2px solid var(--border);border-radius:10px;outline:none;
  transition:border-color .15s;
}
input[type=number]:focus{border-color:var(--green)}
input[type=number]::-webkit-outer-spin-button,
input[type=number]::-webkit-inner-spin-button{-webkit-appearance:none;margin:0}
input[type=number]{-moz-appearance:textfield}
.step-btn{
  flex:0 0 56px;width:56px;min-height:56px;
  background:var(--green);color:#fff;border:none;border-radius:10px;
  font-size:26px;font-weight:700;line-height:1;cursor:pointer;
  display:flex;align-items:center;justify-content:center;
  user-select:none;-webkit-user-select:none;touch-action:manipulation;
  transition:background .15s,transform .05s;
}
.step-btn:hover{background:var(--green-dark)}
.step-btn:active{transform:scale(.94)}
.step-btn:focus-visible{outline:3px solid rgba(11,93,59,.35);outline-offset:2px}

.slider-wrap{position:relative;margin-top:18px;padding-top:30px}
.slider-bubble{
  position:absolute;top:0;left:0;transform:translateX(-50%);
  background:var(--green);color:#fff;font-size:13px;font-weight:700;
  padding:3px 9px;border-radius:8px;white-space:nowrap;pointer-events:none;
  transition:left .05s linear;
}
.slider-bubble::after{
  content:"";position:absolute;left:50%;bottom:-5px;transform:translateX(-50%);
  border:5px solid transparent;border-top-color:var(--green);border-bottom:0;
}
input[type=range]{
  -webkit-appearance:none;appearance:none;width:100%;height:10px;
  border-radius:999px;background:linear-gradient(90deg,#eef5f1,#cfe6da);
  accent-color:var(--green);outline:none;cursor:pointer;margin:6px 0 8px;
  touch-action:pan-y;
}
input[type=range]::-webkit-slider-thumb{
  -webkit-appearance:none;appearance:none;width:30px;height:30px;
  border-radius:50%;background:var(--green);border:4px solid #fff;
  box-shadow:0 2px 8px rgba(11,93,59,.4);cursor:pointer;
}
input[type=range]::-moz-range-thumb{
  width:28px;height:28px;border-radius:50%;background:var(--green);
  border:4px solid #fff;box-shadow:0 2px 8px rgba(11,93,59,.4);cursor:pointer;
}
input[type=range]:focus-visible{box-shadow:0 0 0 3px rgba(11,93,59,.25)}
.slider-scale{
  display:flex;justify-content:space-between;
  font-size:12px;color:var(--muted);margin-top:2px;
}
@media(hover:none) and (pointer:coarse){
  input[type=range]{height:14px}
  input[type=range]::-webkit-slider-thumb{width:36px;height:36px}
  input[type=range]::-moz-range-thumb{width:34px;height:34px}
  .step-btn{flex-basis:60px;width:60px;min-height:60px}
}
.hint{font-size:13px;color:var(--muted)}

.result{display:none;margin-top:20px;border-top:1px dashed var(--border);padding-top:20px}
.result.show{display:block}
.total-box{
  background:linear-gradient(135deg,#0b5d3b,#0e7a4e);color:#fff;
  border-radius:12px;padding:20px;text-align:center;margin-bottom:18px;
}
.total-box .amt{font-size:38px;font-weight:800;line-height:1.1}
.total-box .lbl{font-size:14px;opacity:.9;margin-top:4px}
.meta-row{display:flex;flex-wrap:wrap;gap:12px;margin-bottom:16px}
.meta-pill{
  flex:1;min-width:140px;background:#eef5f1;border:1px solid var(--border);
  border-radius:10px;padding:12px 14px;text-align:center;
}
.meta-pill b{display:block;font-size:18px;color:var(--green-dark)}
.meta-pill span{font-size:12px;color:var(--muted)}

table{width:100%;border-collapse:collapse;font-size:14px;margin:10px 0 4px}
th,td{padding:10px 12px;text-align:left;border-bottom:1px solid var(--border)}
th{background:#eef5f1;color:var(--green-dark);font-weight:700}
td.num,th.num{text-align:right}
tr.free td{color:var(--green);font-weight:600}
tfoot td{font-weight:800;background:#f4f7f5}
.table-scroll{overflow-x:auto}

.tariff-tables{display:grid;grid-template-columns:1fr;gap:20px}
@media(min-width:760px){.tariff-tables{grid-template-columns:1fr 1fr}}
.tariff-tables h3{margin-top:0}
.note{
  background:#fff8e8;border:1px solid #f0d999;border-left:4px solid var(--accent);
  border-radius:8px;padding:14px 16px;font-size:14px;margin-top:16px;
}
.note b{color:#8a5b00}

details{border:1px solid var(--border);border-radius:10px;margin-bottom:10px;background:#fff}
details summary{
  padding:14px 16px;font-weight:700;cursor:pointer;list-style:none;
  display:flex;justify-content:space-between;align-items:center;font-size:15px;
}
details summary::-webkit-details-marker{display:none}
details summary::after{content:"+";font-size:20px;color:var(--green)}
details[open] summary::after{content:"–"}
details .ans{padding:0 16px 16px;font-size:14px;color:var(--muted)}

footer{background:var(--green-dark);color:#cfe6da;padding:26px 0;font-size:13px;text-align:center}
footer a{color:#fff}
.disclaimer{font-size:12px;color:var(--muted);margin-top:18px;line-height:1.5}
.err{color:#c0392b;font-size:14px;font-weight:600;margin-top:8px;display:none}
.err.show{display:block}