/* =========================================================
 * guideway-selection / css/style.css
 * Shared styling for all pages. Light engineering theme
 * (same variable scheme as the sibling screw-selection app).
 * ========================================================= */
:root {
  --bg: #f4f6f9;
  --surface: #ffffff;
  --border: #dfe4ea;
  --text: #1f2937;
  --text-muted: #6b7280;
  --accent: #2563eb;
  --accent-dark: #1e40af;
  --accent-light: #eaf1fe;
  --warn-bg: #fef3c7;
  --warn-border: #f59e0b;
  --err-bg: #fee2e2;
  --err-border: #dc2626;
  --ok-bg: #dcfce7;
  --ok-border: #16a34a;
  --radius: 10px;
  --shadow: 0 1px 3px rgba(15, 23, 42, 0.08);
}

[data-theme="dark"] {
  --bg: #0f172a;
  --surface: #1e293b;
  --border: #334155;
  --text: #e2e8f0;
  --text-muted: #94a3b8;
  --accent: #3b82f6;
  --accent-dark: #60a5fa;
  --accent-light: #1e3a5f;
  --warn-bg: #3a2e10;
  --warn-border: #d97706;
  --err-bg: #3f1d1d;
  --err-border: #ef4444;
  --ok-bg: #14321f;
  --ok-border: #22c55e;
  --shadow: none;
}

* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }

body {
  font-family: "Segoe UI", system-ui, -apple-system, "PingFang SC", "Microsoft YaHei", "Hiragino Sans", "Noto Sans", sans-serif;
  background: var(--bg);
  color: var(--text);
  font-size: 15px;
  line-height: 1.55;
}

/* ---------------- top bar ---------------- */

.topbar {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 10px 18px;
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 20;
  flex-wrap: wrap;
}
.brand {
  display: flex;
  align-items: center;
  gap: 8px;
  font-weight: 500;
  color: var(--text);
  text-decoration: none;
  white-space: nowrap;
}
.logo { font-size: 20px; }
.tabs { display: flex; gap: 4px; flex-wrap: wrap; }
.tabs a {
  padding: 6px 12px;
  border-radius: 8px;
  text-decoration: none;
  color: var(--text-muted);
  white-space: nowrap;
}
.tabs a:hover { background: var(--accent-light); color: var(--text); }
.tabs a[aria-current="page"] { background: var(--accent-light); color: var(--accent-dark); font-weight: 500; }
.spacer { flex: 1; }
.actions { display: flex; align-items: center; gap: 8px; flex-wrap: wrap; }
.lang-wrap { color: var(--text-muted); font-size: 13px; white-space: nowrap; }
.lang-wrap select {
  padding: 4px 6px;
  border: 1px solid var(--border);
  border-radius: 6px;
  background: var(--surface);
  color: var(--text);
}
.btn {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  padding: 6px 12px;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: var(--surface);
  color: var(--text);
  text-decoration: none;
  cursor: pointer;
  font-size: 14px;
}
.btn:hover { border-color: var(--accent); color: var(--accent); }

/* ---------------- layout ---------------- */

.container { max-width: 1100px; margin: 0 auto; padding: 20px 16px 60px; }
.page-title { font-size: 24px; font-weight: 500; margin: 10px 0 6px; }
.live-note, .note { color: var(--text-muted); font-size: 13px; margin: 6px 0 12px; }
.grid { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; align-items: start; }
@media (max-width: 860px) { .grid { grid-template-columns: 1fr; } }

.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 16px 18px;
  margin-bottom: 16px;
}
.card h2 { font-size: 16px; font-weight: 500; margin: 0 0 10px; }

/* ---------------- inputs ---------------- */

.input-row {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 6px;
}
.input-row label { flex: 1; font-size: 14px; }
.input-row input, .input-row select {
  width: 130px;
  padding: 6px 8px;
  border: 1px solid var(--border);
  border-radius: 6px;
  background: var(--surface);
  color: var(--text);
  font-size: 14px;
}
.input-row input:focus-visible, .input-row select:focus-visible,
.btn:focus-visible, a:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 1px;
}
.btn-row { display: flex; gap: 8px; flex-wrap: wrap; margin-top: 10px; }

/* ---------------- results ---------------- */

.result-row {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 12px;
  padding: 5px 8px;
  border-bottom: 1px dashed var(--border);
  font-size: 14px;
}
.result-row span { color: var(--text-muted); }
.result-row b { font-weight: 500; text-align: right; white-space: nowrap; }
.result-row.hl { background: var(--accent-light); border-radius: 6px; border-bottom-color: transparent; }
.result-row.hl b { color: var(--accent-dark); }

/* ---------------- tables ---------------- */

.table-wrap { overflow-x: auto; }
table.cat-table { width: 100%; border-collapse: collapse; font-size: 13px; }
.cat-table th, .cat-table td {
  border-bottom: 1px solid var(--border);
  padding: 6px 8px;
  text-align: left;
  white-space: nowrap;
}
.cat-table th { color: var(--text-muted); font-weight: 400; font-size: 12px; }
.cat-table td.num, .cat-table th.num { text-align: right; font-variant-numeric: tabular-nums; }
.cat-table tr.row-hl td { background: var(--accent-light); }
.cat-table tr.row-picked td { font-weight: 500; color: var(--accent-dark); }

/* ---------------- alerts ---------------- */

.alert {
  border-radius: 8px;
  padding: 8px 12px;
  font-size: 13px;
  margin-top: 10px;
  border: 1px solid transparent;
}
.alert.err { background: var(--err-bg); border-color: var(--err-border); color: var(--text); }
.alert.warn { background: var(--warn-bg); border-color: var(--warn-border); color: var(--text); }
.alert.ok { background: var(--ok-bg); border-color: var(--ok-border); color: var(--text); }

/* ---------------- home ---------------- */

.home-hero { text-align: center; padding: 26px 0 8px; }
.home-hero h1 { font-size: 26px; font-weight: 500; margin: 0 0 8px; }
.home-hero p { color: var(--text-muted); max-width: 640px; margin: 0 auto; }
.home-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 16px;
  margin-top: 22px;
}
.home-grid .card { display: block; text-decoration: none; color: var(--text); margin-bottom: 0; }
.home-grid .card h2 { color: var(--accent-dark); }
.home-grid .card:hover { border-color: var(--accent); }
.home-grid .card p { color: var(--text-muted); font-size: 13px; margin: 0; }

/* ---------------- theory ---------------- */

.formula {
  font-family: "Cambria Math", "STIX Two Math", Georgia, serif;
  background: var(--accent-light);
  border-radius: 8px;
  padding: 10px 14px;
  margin: 8px 0 14px;
  overflow-x: auto;
  white-space: nowrap;
  font-size: 15px;
}

/* ---------------- duty-spectrum segments ---------------- */

.seg-table { width: 100%; border-collapse: collapse; font-size: 13px; margin-top: 6px; }
.seg-table th { color: var(--text-muted); font-weight: 400; font-size: 12px; text-align: left; padding: 4px 6px; }
.seg-table th.num, .seg-table td.num { text-align: right; }
.seg-table td { padding: 4px 6px; }
.seg-table input { width: 110px; max-width: 100%; }
.btn-sm { padding: 2px 9px; font-size: 12px; }

/* ---------------- schematic ---------------- */

canvas.schem {
  width: 100%;
  max-width: 560px;
  height: auto;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: var(--bg);
  display: block;
  margin-top: 8px;
}

/* ---------------- footer ---------------- */

.footer {
  text-align: center;
  color: var(--text-muted);
  font-size: 12px;
  padding: 22px 12px 30px;
  border-top: 1px solid var(--border);
}
.footer a { color: var(--text-muted); }

/* ---------------- print ---------------- */

@media print {
  .topbar, .btn-row, .actions, .footer, .no-print { display: none !important; }
  body { background: #fff; color: #000; }
  .card { border: 1px solid #ccc; box-shadow: none; break-inside: avoid; }
  .container { max-width: none; padding: 0; }
}

/* ---------------- theory TOC (W14) ---------------- */

.toc a {
  display: inline-block;
  margin: 3px 14px 3px 0;
  color: var(--accent-dark);
  text-decoration: none;
}
.toc a:hover { text-decoration: underline; }