/* PyroHeater Web — light theme */
:root{
  --bg:#f4f6f9; --panel:#ffffff; --ink:#1f2a36; --muted:#6b7785;
  --line:#d8dee6; --accent:#2a6fdb; --accent2:#e4572e; --ok:#2a9d8f; --warn:#e9a23b;
  --shadow:0 1px 3px rgba(20,30,45,.08),0 6px 18px rgba(20,30,45,.06);
}
*{box-sizing:border-box}
body{margin:0;font-family:system-ui,"Segoe UI",Roboto,Arial,"PingFang SC","Microsoft YaHei",sans-serif;
  background:var(--bg);color:var(--ink);font-size:14px;line-height:1.5}
header{background:linear-gradient(90deg,#22364f,#2a6fdb);color:#fff;padding:14px 22px;display:flex;align-items:center;gap:18px;flex-wrap:wrap}
header .brand{font-weight:700;font-size:18px;letter-spacing:.3px}
header .tag{opacity:.85;font-size:12.5px;font-weight:400}
header .spacer{flex:1}
.lang-wrap{display:flex;align-items:center;gap:8px;font-size:12.5px}
.hdr-actions{display:flex;gap:8px;align-items:center;margin-left:4px}
.hdr-btn{display:inline-flex;align-items:center;gap:6px;padding:7px 12px;border:1px solid rgba(255,255,255,.5);border-radius:8px;color:#fff;text-decoration:none;font-size:12.5px;background:rgba(255,255,255,.12);white-space:nowrap}
.hdr-btn:hover{background:rgba(255,255,255,.26)}
.hdr-btn .ic{font-size:14px;line-height:1}
select,input,button{font-family:inherit;font-size:13px}
select{padding:6px 8px;border:1px solid rgba(255,255,255,.4);background:rgba(255,255,255,.15);color:#fff;border-radius:7px}
select option{color:#1f2a36}
.wrap{display:grid;grid-template-columns:minmax(560px,44%) 1fr;gap:18px;padding:18px;align-items:start;max-width:2000px;margin:0 auto}
@media (max-width:1100px){.wrap{grid-template-columns:minmax(420px,1fr)}}
/* Left input panel: lay the parameter cards out in two columns so the
   panel is much shorter and uses the horizontal space. */
.col-inputs{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:16px;align-items:start}
.col-stack{display:flex;flex-direction:column;gap:16px;min-width:0}
.col-stack>.card{margin-bottom:0}
.col-inputs>.btn-row{grid-column:1 / -1}
/* Each stack is an independent vertical flex column, so the cards in a column
   stack tightly one after another regardless of the other column's card heights
   (no grid row-height coupling -> no holes). col-left / col-right are kept as
   semantic markers inside the stacks. */
@media (max-width:680px){.col-inputs{grid-template-columns:1fr}}
/* When the two-card columns get narrow (≈1101–1300px) drop the inner
   field grid from 3 to 2 columns so labels/inputs don't get cramped. */
@media (min-width:1101px) and (max-width:1300px){.col-inputs .grid{grid-template-columns:repeat(2,minmax(0,1fr))}}
.col-inputs .grid{grid-template-columns:repeat(3,minmax(0,1fr))}
.col-inputs .card > .grid > .field:nth-last-child(1):nth-child(odd){grid-column:1 / -1}
.card{background:var(--panel);border:1px solid var(--line);border-radius:12px;box-shadow:var(--shadow);padding:16px 18px;margin-bottom:16px}
.card h2{margin:0 0 4px;font-size:15px;display:flex;align-items:center;gap:8px}
.card h2 .tag2{font-weight:400;font-size:11.5px;color:var(--muted)}
.section-note{font-size:12px;color:var(--muted);margin:2px 0 12px}
.grid{display:grid;grid-template-columns:1fr 1fr;gap:10px 14px}
.field{display:flex;flex-direction:column;gap:3px}
.field label{font-size:12px;color:var(--muted)}
.field input,.field select{width:100%;padding:7px 9px;border:1px solid var(--line);border-radius:7px;background:#fbfcfe;color:var(--ink)}
.field input:focus,.field select:focus{outline:none;border-color:var(--accent);box-shadow:0 0 0 3px rgba(42,111,219,.15)}
.full{grid-column:1 / -1}
.btn-row{display:flex;gap:10px;margin-top:6px}
button.primary{background:var(--accent);color:#fff;border:none;padding:9px 18px;border-radius:8px;font-weight:600;cursor:pointer}
button.primary:hover{background:#1f5bc0}
button.ghost{background:#eef2f7;color:var(--ink);border:1px solid var(--line);padding:9px 16px;border-radius:8px;cursor:pointer}
button.ghost:hover{background:#e3e9f1}
.subhead{font-size:12px;font-weight:700;color:var(--accent);margin:14px 0 8px;text-transform:uppercase;letter-spacing:.4px}
.coil{border:1px dashed var(--line);border-radius:9px;padding:10px;margin-bottom:10px;position:relative;background:#fbfcfe}
.coil .rm{position:absolute;top:8px;right:8px;font-size:11px;color:var(--accent2);cursor:pointer;border:none;background:none}
.results .res-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(190px,1fr));gap:10px}
.metric{background:#f7f9fc;border:1px solid var(--line);border-radius:9px;padding:10px 12px}
.metric .k{font-size:11.5px;color:var(--muted)}
.metric .v{font-size:17px;font-weight:700;color:var(--ink);margin-top:2px}
.metric .u{font-size:11px;color:var(--muted);font-weight:400}
table.tbl{width:100%;border-collapse:collapse;font-size:12.5px;margin-top:8px}
table.tbl th,table.tbl td{border:1px solid var(--line);padding:6px 8px;text-align:right}
table.tbl th{background:#eef2f7;color:#33404d}
table.tbl td:first-child,table.tbl th:first-child{text-align:left}
.warn{background:#fff4e0;border:1px solid #f0d28a;color:#8a5a00;padding:8px 10px;border-radius:8px;font-size:12px;margin-top:10px}
.ok{background:#e7f6f2;border:1px solid #a9ddd2;color:#1c6b5e;padding:8px 10px;border-radius:8px;font-size:12px;margin-top:10px}
.bad{background:#fdeaea;border:1px solid #f1a9a9;color:#a11;padding:8px 10px;border-radius:8px;font-size:12px;margin-top:10px}
.hidable.hidden{display:none}
.sub{font-weight:600;color:var(--muted);font-size:12px;margin:10px 0 2px;grid-column:1/-1}
.chart-box{margin-top:12px;background:#fff;border:1px solid var(--line);border-radius:10px;padding:6px}
.tabs{display:flex;gap:6px;flex-wrap:wrap;margin-bottom:10px}
.tab{padding:7px 12px;border:1px solid var(--line);background:#eef2f7;border-radius:20px;cursor:pointer;font-size:12.5px;color:var(--muted)}
.tab.active{background:var(--accent);color:#fff;border-color:var(--accent)}
.hidden{display:none}
footer{padding:14px 22px;color:var(--muted);font-size:11.5px;text-align:center}
code{background:#eef2f7;padding:1px 5px;border-radius:4px;font-size:12px}
.pill{display:inline-block;font-size:11px;padding:2px 8px;border-radius:20px;background:#eef2f7;color:var(--muted);margin-left:6px}