:root {
  --bg: #f4f7fb;
  --card: #ffffff;
  --ink: #1f2937;
  --muted: #6b7280;
  --brand: #1f5fa8;
  --brand-dark: #174a85;
  --accent: #0e8a6d;
  --line: #e3e8ef;
  --head-bg: linear-gradient(135deg, #1f5fa8, #123d6e);
  --radius: 12px;
  --shadow: 0 6px 24px rgba(23, 61, 110, 0.08);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: -apple-system, 'Segoe UI', Roboto, 'Helvetica Neue', Arial,
    'PingFang SC', 'Microsoft YaHei', 'Noto Sans KR', 'Noto Sans JP', sans-serif;
  background: var(--bg);
  color: var(--ink);
  line-height: 1.55;
}

a { color: var(--brand); text-decoration: none; }
a:hover { text-decoration: underline; }

/* ------------------------------------------------------------------ */
/* Header / topbar                                                      */
/* ------------------------------------------------------------------ */
#siteHeader {
  position: sticky;
  top: 0;
  z-index: 50;
  background: var(--head-bg);
  color: #fff;
  box-shadow: 0 3px 14px rgba(6, 28, 58, 0.25);
}
.topbar {
  max-width: 1180px;
  margin: 0 auto;
  padding: 12px 20px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  flex-wrap: wrap;
}
.topbar-links { display: flex; gap: 10px; flex-wrap: wrap; }
.btn {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  border: 0;
  cursor: pointer;
  font-size: 14px;
  font-weight: 600;
  border-radius: 9px;
  padding: 9px 16px;
  transition: transform .08s ease, box-shadow .15s ease, background .15s ease;
}
.btn:active { transform: translateY(1px); }
.btn-ghost {
  background: rgba(255, 255, 255, 0.12);
  color: #fff;
  border: 1px solid rgba(255, 255, 255, 0.35);
}
.btn-ghost:hover {
  background: rgba(255, 255, 255, 0.22);
  text-decoration: none;
}
.btn .ic { font-size: 15px; }
.lang-wrap { display: flex; align-items: center; gap: 8px; }
.lang-label { font-size: 13px; opacity: .9; }
.lang-select {
  font-size: 14px;
  padding: 7px 10px;
  border-radius: 8px;
  border: 1px solid rgba(255, 255, 255, 0.5);
  background: #fff;
  color: var(--ink);
  font-weight: 600;
}

/* ------------------------------------------------------------------ */
/* Layout                                                               */
/* ------------------------------------------------------------------ */
.wrap {
  max-width: 1180px;
  margin: 0 auto;
  padding: 28px 20px 60px;
}
.page-head { margin-bottom: 22px; }
.page-head h1 { font-size: 26px; margin: 0 0 6px; color: var(--brand-dark); }
.page-head p { margin: 0; color: var(--muted); max-width: 820px; }

.grid { display: grid; gap: 18px; }
.grid.cols-2 { grid-template-columns: 1fr 1fr; }
.grid.cols-1-1 { grid-template-columns: minmax(0, 3fr) minmax(0, 2fr); }

.card {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 20px 22px;
}
.card h2 {
  margin: 0 0 14px;
  font-size: 17px;
  color: var(--brand-dark);
  border-left: 4px solid var(--brand);
  padding-left: 10px;
}
.card h3 {
  margin: 18px 0 10px;
  font-size: 15px;
  color: var(--brand-dark);
}

/* ------------------------------------------------------------------ */
/* Forms                                                                */
/* ------------------------------------------------------------------ */
.form-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 12px 18px; }
@media (max-width: 720px){ .form-grid{ grid-template-columns: 1fr; } }
.field { display: flex; flex-direction: column; gap: 4px; }
.field label { font-size: 13px; font-weight: 600; color: #374151; }
.field .unit { color: var(--muted); font-weight: 500; font-size: 12px; }
.field input[type="number"], .field select, .field input[type="text"] {
  width: 100%;
  padding: 10px 12px;
  font-size: 15px;
  border: 1px solid #ccd5e0;
  border-radius: 8px;
  background: #fbfcfe;
  color: var(--ink);
}
.field input:focus, .field select:focus {
  outline: 2px solid rgba(31, 95, 168, 0.35);
  border-color: var(--brand);
}
.hint { font-size: 12px; color: var(--muted); }

/* ------------------------------------------------------------------ */
/* Buttons-bar / results                                                */
/* ------------------------------------------------------------------ */
.actions {
  display: flex;
  gap: 12px;
  margin: 20px 0 0;
  align-items: center;
}
.btn-primary {
  background: var(--brand);
  color: #fff;
}
.btn-primary:hover { background: var(--brand-dark); text-decoration: none; }
.btn-secondary {
  background: #eef2f7;
  color: var(--brand-dark);
  border: 1px solid #d5dde7;
}
.btn-secondary:hover { background: #e3eaf2; text-decoration: none; }

.result-table { width: 100%; border-collapse: collapse; font-size: 14px; }
.result-table caption { caption-side: top; text-align: left; font-weight: 700; color: var(--brand-dark); padding-bottom: 6px; font-size:15px;}
.result-table th, .result-table td {
  border: 1px solid var(--line);
  padding: 8px 12px;
  text-align: right;
  white-space: nowrap;
}
.result-table th { background: #eef4fb; color: #123a63; font-weight: 600; white-space: normal; }
.result-table td.metric { text-align: left; font-weight: 600; color: #374151; min-width: 200px; white-space: normal; }
.result-table tr:nth-child(even) td { background: #f8fafd; }
.result-table td.result { font-variant-numeric: tabular-nums; font-weight: 600; }

.kpi-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); gap: 14px; margin: 6px 0 4px; }
.kpi {
  background: linear-gradient(160deg, #eef4fb, #f7fafd);
  border: 1px solid #d5e2f2;
  border-radius: 10px;
  padding: 14px 16px;
}
.kpi .k { font-size: 12px; color: var(--muted); font-weight: 600; }
.kpi .v { font-size: 22px; font-weight: 800; color: var(--brand-dark); margin-top: 2px; font-variant-numeric: tabular-nums; }
.kpi .u { font-size: 12px; color: var(--muted); margin-left: 4px; font-weight: 600; }

.badge { display:inline-block; padding:2px 10px; border-radius:20px; font-size:12px; font-weight:700; }
.badge.ok { background:#e4f7ee; color:#0e8a6d; }
.badge.warn { background:#fdf0d9; color:#9a6200; }
.badge.bad { background:#fde4e3; color:#c0392b; }

/* ------------------------------------------------------------------ */
/* Home cards                                                           */
/* ------------------------------------------------------------------ */
.tool-grid { display:grid; grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); gap:20px; }
.tool-card {
  background: var(--card);
  border:1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 24px;
  display:flex;
  flex-direction:column;
  gap:10px;
  transition: transform .12s ease, box-shadow .15s ease;
}
.tool-card:hover { transform: translateY(-3px); box-shadow: 0 12px 30px rgba(23,61,110,.14); }
.tool-card .tc-icon { font-size: 30px; }
.tool-card h3 { margin:0; font-size:18px; color:var(--brand-dark); }
.tool-card p { margin:0; color:var(--muted); font-size:14px; flex:1; }
.tool-card .go {
  align-self:flex-start;
  margin-top:6px;
  background:var(--brand);
  color:#fff;
}
.tool-card .go:hover { background:var(--brand-dark); text-decoration:none; }

.home-hero {
  background: var(--head-bg);
  border-radius: var(--radius);
  color:#fff;
  padding: 34px 30px;
  margin-bottom: 26px;
}
.home-hero h1 { margin:0 0 8px; font-size:32px; }
.home-hero p { margin:0; opacity:.9; max-width:780px; }

.section-title { font-size:20px; color:var(--brand-dark); margin:8px 0 16px; }

.footer {
  border-top:1px solid var(--line);
  padding:22px 20px;
  text-align:center;
  color:var(--muted);
  font-size:13px;
  background:#fff;
}

@media (max-width: 820px){
  .grid.cols-2, .grid.cols-1-1 { grid-template-columns: 1fr; }
  .page-head h1 { font-size: 22px; }
}
.note {
  font-size: 12.5px; color:#7c5b00;
  background:#fff8e6; border:1px solid #f0e2b8;
  border-radius:8px; padding:10px 12px; margin-top:14px;
}

/* ------------------------------------------------------------------ */
/* Property quick-fill + misc toolbars                                  */
/* ------------------------------------------------------------------ */
.fluidbar {
  display:flex; align-items:center; gap:10px; flex-wrap:wrap;
  margin-bottom: 4px; background:#f2f7fc; border:1px solid #dbe7f3;
  border-radius:8px; padding:8px 12px;
}
.fluidbar label { font-size:13px; font-weight:600; color:#33465c; }
.fluidbar select {
  flex:1; min-width:160px; padding:8px 10px; font-size:14px;
  border:1px solid #ccd5e0; border-radius:8px; background:#fff; color:var(--ink);
}
.fluidbar .hint { font-size:12px; color:var(--muted); }

.toolbar {
  display:flex; gap:10px; flex-wrap:wrap; align-items:center;
  margin-top: 18px;
}
.btn-accent {
  background:var(--accent); color:#fff;
}
.btn-accent:hover { background:#0b755d; text-decoration:none; }

/* ------------------------------------------------------------------ */
/* Formula reference (collapsible detail popover)                       */
/* ------------------------------------------------------------------ */
.formula {
  margin: 16px 0 0;
  border:1px dashed #c6d6ea;
  border-radius:10px;
  background:#fbfdff;
  padding: 10px 14px;
}
.formula summary {
  cursor:pointer; font-weight:700; font-size:13.5px; color:var(--brand-dark);
  list-style:none;
}
.formula summary::-webkit-details-marker { display:none; }
.formula summary::before { content:"?"; display:inline-block; width:18px; height:18px;
  border-radius:50%; background:var(--brand); color:#fff; text-align:center;
  font-size:12px; line-height:18px; margin-right:8px; }
.formula table { width:100%; border-collapse:collapse; font-size:13px; margin-top:8px; }
.formula td { border-bottom:1px solid var(--line); padding:5px 6px; vertical-align:top;
  overflow-wrap:anywhere; word-break:break-word; }
.formula td.sym { font-weight:700; color:var(--brand-dark); white-space:nowrap; min-width:110px; }
.formula td.ref { font-weight:600; color:#174a85; min-width:120px; font-size:12px;
  background:#f3f6fb; border-radius:6px; }
.formula .eq { font-family:'Cambria Math', 'Times New Roman', Georgia, serif; font-style:italic;
  color:#14532d; font-weight:600; }

/* ------------------------------------------------------------------ */
/* T–Q / temperature-profile chart box                                  */
/* ------------------------------------------------------------------ */
.chart-box {
  margin-top:16px; border:1px solid var(--line); border-radius:10px;
  background:#fff; padding:12px 14px;
}
.chart-box h4 {
  margin:0 0 8px; font-size:13.5px; color:var(--brand-dark);
}
.chart-box svg { width:100%; height:auto; display:block; }
.chart-legend { display:flex; gap:16px; flex-wrap:wrap; margin-top:8px; font-size:12px; color:var(--muted); }
.chart-legend i { display:inline-block; width:14px; height:3px; border-radius:2px; margin-right:6px; vertical-align:middle; }

/* ------------------------------------------------------------------ */
/* Datasheet / report tables (TEMA-style)                               */
/* ------------------------------------------------------------------ */
.ds-table { width:100%; border-collapse:collapse; font-size:12.5px; margin-top:10px; }
.ds-table th, .ds-table td { border:1px solid #c9d3df; padding:6px 9px; text-align:left; vertical-align:top; }
.ds-table th { background:#e7eef7; color:#123a63; font-weight:700; min-width:150px; }
.ds-table td.metric { background:#f6f9fd; font-weight:600; color:#374151; min-width:180px; }
.ds-table input, .ds-table select { width:100%; border:1px solid transparent; background:transparent;
  font:inherit; color:var(--ink); padding:2px; }
.ds-table input:focus, .ds-table select:focus { border-color:var(--brand); background:#fff; outline:none; }
.ds-title { display:flex; justify-content:space-between; align-items:center; gap:12px; flex-wrap:wrap;
  margin-bottom:6px; }
.ds-title h2 { border:none; padding:0; }
.ds-brand { font-size:11px; color:var(--muted); text-align:right; }

/* ------------------------------------------------------------------ */
/* Compare module                                                       */
/* ------------------------------------------------------------------ */
.cmp-layout { display:grid; grid-template-columns: minmax(0,1fr) minmax(0,2fr); gap:18px; }
@media (max-width:820px){ .cmp-layout{ grid-template-columns:1fr; } }
.cmp-actions { display:flex; gap:8px; flex-wrap:wrap; margin-top:10px; }
.cmp-save-name { display:flex; gap:8px; margin-top:12px; }
.cmp-save-name input { flex:1; padding:8px 10px; border:1px solid #ccd5e0; border-radius:8px; font-size:14px; }
.saved-item {
  display:flex; align-items:center; justify-content:space-between; gap:8px;
  border:1px solid var(--line); border-radius:8px; padding:8px 10px; margin-top:8px; background:#fbfdff;
}
.saved-item .name { font-weight:700; color:var(--brand-dark); font-size:14px; }
.saved-item .meta { font-size:12px; color:var(--muted); }
.saved-item .del { color:#c0392b; background:none; border:none; cursor:pointer; font-size:16px; line-height:1; }

/* ------------------------------------------------------------------ */
/* Print / report                                                       */
/* ------------------------------------------------------------------ */
@media print {
  @page { margin: 14mm; }
  body { background:#fff; }
  #siteHeader, .toolbar, .actions, .lang-wrap, .footer,
  #printBtn, .btn-print, .fluidbar, details.formula { display:none !important; }
  .card { box-shadow:none; border:1px solid #ccc; }
  .chart-box svg { max-width: 100%; }
  .wrap { padding:0; }
}
.toolbar.print-only-print, .btn-print { }