:root{
  --green:#2e8b57; --green-d:#1f6b40; --lime:#9ccb3b; --ink:#17322a; --muted:#5f7f72;
  --bg:#f4f8f2; --card:#ffffff; --line:#dcebdd; --amber:#e0a63c;
  --shadow:0 8px 30px rgba(23,50,42,.08);
}
*{box-sizing:border-box}
body{
  margin:0; font-family:-apple-system,"Segoe UI",Roboto,Helvetica,Arial,sans-serif;
  background:var(--bg); color:var(--ink); line-height:1.5;
}
.topbar{
  background:linear-gradient(135deg,var(--green-d),var(--green) 55%,var(--lime));
  color:#fff; padding:20px 28px; display:flex; justify-content:space-between; align-items:center;
}
.brand{display:flex; gap:14px; align-items:center}
.logo{font-size:34px}
.topbar h1{margin:0; font-size:24px}
.tag{margin:2px 0 0; opacity:.9; font-size:13px}
.pill{background:rgba(255,255,255,.18); padding:6px 14px; border-radius:999px; font-size:13px; font-weight:600}
main{max-width:960px; margin:26px auto; padding:0 18px; display:flex; flex-direction:column; gap:22px}
.card{background:var(--card); border:1px solid var(--line); border-radius:16px; padding:26px 26px; box-shadow:var(--shadow); margin-bottom:0}
.card h2{margin:0 0 4px; font-size:20px}
.card .sub{margin:4px 0 20px; color:var(--muted); font-size:14px}
.inputs{display:grid; grid-template-columns:repeat(3,1fr); gap:14px 16px}
label{display:flex; flex-direction:column; font-size:13px; font-weight:600; color:var(--muted); gap:5px}
label.adv{grid-column:auto}
input,select{
  padding:9px 11px; border:1px solid var(--line); border-radius:9px; font-size:15px; background:#fbfdfb; color:var(--ink);
}
input:focus,select:focus{outline:2px solid var(--lime); border-color:var(--green)}
.btn{
  margin-top:18px; background:var(--green); color:#fff; border:none; border-radius:11px;
  padding:13px 22px; font-size:16px; font-weight:700; cursor:pointer; transition:.15s;
}
.btn:hover{background:var(--green-d); transform:translateY(-1px)}
.btn.ghost{background:#fff; color:var(--green); border:2px solid var(--green); margin-top:0}
.btn.ghost:hover{background:#eef7f0}
.err{color:#c0392b; font-weight:600; margin-top:12px}
.hidden{display:none}

.steps{display:grid; grid-template-columns:repeat(3,1fr); gap:16px; margin-top:6px}
.step{border:1px solid var(--line); border-radius:14px; padding:16px 16px; background:#fbfdfb}
.step-head{display:flex; align-items:center; gap:9px}
.step-head .num{background:var(--green); color:#fff; width:24px; height:24px; border-radius:50%; display:flex; align-items:center; justify-content:center; font-size:13px; font-weight:700}
.step h3{margin:0; font-size:15px}
.lead{font-size:26px; font-weight:800; margin:12px 0 4px; color:var(--green-d)}
.detail{font-size:14px; color:var(--muted); margin:2px 0}
.axis{display:flex; justify-content:space-between; font-size:11px; color:var(--muted); margin-top:2px}
canvas{width:100%; height:auto; margin-top:8px; background:#f4f8f2; border-radius:9px}
.tiny{font-size:12px; color:var(--muted); margin:6px 0 0}
.hint{margin:14px 0 0; padding:10px 12px; background:#eef7f0; border-left:4px solid var(--green); border-radius:8px; font-size:13px; color:var(--ink)}

.how{margin-top:20px; border-top:1px dashed var(--line); padding-top:14px}
.how summary{cursor:pointer; font-weight:700; color:var(--green-d); font-size:14px}
.how ol{margin:12px 0; padding-left:20px; font-size:14px}
.how li{margin:6px 0}

.upload{display:flex; gap:12px; align-items:center; margin-top:6px}
.upload input[type=file]{flex:1; padding:9px; border:1px dashed var(--line); border-radius:9px; background:#fbfdfb; font-size:14px}
.vresults{margin-top:18px; border:1px solid var(--line); border-radius:12px; padding:16px; background:#fbfdfb}
.vrow{display:flex; justify-content:space-between; padding:7px 0; border-bottom:1px solid var(--line); font-size:15px}
.vrow:last-of-type{border-bottom:none}
.vrow span{color:var(--muted)}
footer{max-width:960px; margin:26px auto 40px; padding:0 18px; color:var(--muted); font-size:12px; text-align:center}
@media (max-width:720px){ .inputs{grid-template-columns:1fr 1fr} .steps{grid-template-columns:1fr} .brand{flex-direction:column; align-items:flex-start; gap:4px} .topbar{flex-direction:column; gap:10px; align-items:flex-start} }