/* CalcHandbook — Section Properties tool styles (shared) */
* { box-sizing: border-box; margin: 0; padding: 0; }
:root {
  --bg: #0c1c38; --surface: #ffffff; --surface-alt: #f5f8fc; --surface-sunken: #e3eaf3;
  --line: #cfd9e8; --line-2: #9eb3cf;
  --line-on-dark: rgba(255,255,255,0.10); --line-on-dark-2: rgba(255,255,255,0.22);
  --navy: #0c1e3e; --navy-2: #1e3a6f;
  --ink: #0c1e3e; --ink-2: #2c4670; --ink-3: #6c7f9c; --ink-inv: #ffffff;
  --on-dark: #eef3fb; --on-dark-2: #b5c3da; --on-dark-3: #7a8caa;
  --accent: #f5b840; --accent-2: #ffc962; --accent-soft: rgba(245,184,64,0.14);
  --c-x: #1565c0; --c-y: #6d4ec7; --c-c: #c0392b; --c-p: #c0651a; --c-dim: #2c4670;
  --shadow-sm: 0 1px 2px rgba(0,0,0,0.25); --shadow-md: 0 12px 32px -10px rgba(0,0,0,0.45);
  --radius: 14px; --radius-sm: 8px; --radius-xs: 4px;
  --font-ui: 'Inter',-apple-system,BlinkMacSystemFont,'Segoe UI',Roboto,system-ui,sans-serif;
  --font-serif: 'Source Serif 4','Cambria',Georgia,serif;
  --font-math: 'Cambria Math','Cambria','Times New Roman',Georgia,serif;
}
html,body { background:var(--bg); color:var(--on-dark); font-family:var(--font-ui); -webkit-font-smoothing:antialiased; }
body { min-height:100vh; padding:32px 28px 60px;
  background-image:radial-gradient(ellipse at top left,rgba(59,130,246,0.12),transparent 50%),radial-gradient(ellipse at bottom right,rgba(245,184,64,0.06),transparent 60%),linear-gradient(180deg,#0c1c38,#0a1730);
  background-attachment:fixed; }
.app { max-width:1380px; margin:0 auto; }
.topbar { display:flex; justify-content:space-between; align-items:flex-end; gap:20px; padding-bottom:22px; border-bottom:1px solid var(--line-on-dark); margin-bottom:28px; }
.topbar-left { display:flex; align-items:stretch; gap:22px; min-width:0; }
.brand { display:flex; align-items:center; gap:10px; font-family:var(--font-serif); font-size:20px; font-weight:600; color:var(--on-dark); text-decoration:none; }
.brand-mark { width:28px; height:28px; border-radius:7px; background:var(--accent); color:var(--navy); display:inline-flex; align-items:center; justify-content:center; font-family:var(--font-ui); font-weight:800; font-size:12px; }
.brand em { font-style:normal; color:var(--accent); }
.divider { width:1px; background:var(--line-on-dark); align-self:stretch; }
.figure-meta { display:flex; flex-direction:column; gap:4px; }
.fig-title { font-family:var(--font-serif); font-size:22px; font-weight:600; letter-spacing:-0.015em; line-height:1.2; color:var(--on-dark); }
.fig-title .em-dash { color:var(--on-dark-3); font-weight:400; margin:0 4px; }
.fig-sub { font-size:12px; color:var(--on-dark-2); font-style:italic; margin-top:2px; }
.topbar-right { display:flex; gap:10px; align-items:center; flex-shrink:0; }
.unit-toggle { display:inline-flex; background:rgba(255,255,255,0.05); border:1px solid var(--line-on-dark-2); border-radius:var(--radius-sm); padding:3px; gap:2px; }
.unit-btn { padding:6px 12px; border:none; background:transparent; font-family:inherit; font-size:11.5px; font-weight:600; color:var(--on-dark-2); cursor:pointer; border-radius:5px; letter-spacing:0.04em; display:inline-flex; align-items:center; gap:5px; }
.unit-btn.active { background:var(--accent); color:var(--navy); }
.unit-btn .unit-tag { font-size:9.5px; font-weight:500; opacity:0.7; text-transform:uppercase; }
.btn { display:inline-flex; align-items:center; gap:7px; padding:8px 14px; font-family:inherit; font-size:12.5px; font-weight:500; border-radius:var(--radius-sm); border:1px solid var(--line-on-dark-2); background:rgba(255,255,255,0.04); color:var(--on-dark); cursor:pointer; }
.btn:hover { background:rgba(255,255,255,0.10); }
.btn-primary { background:var(--accent); color:var(--navy); border-color:var(--accent); font-weight:600; }
.btn svg { width:14px; height:14px; }
.workspace { display:grid; grid-template-columns:minmax(420px,1.05fr) minmax(380px,0.95fr); gap:24px; align-items:start; }
@media (max-width:980px) { .workspace { grid-template-columns:1fr; } .diagram-pane { position:static !important; } }
.diagram-pane { position:sticky; top:24px; }
.diagram-card { background:var(--surface); border:1px solid var(--line); border-radius:var(--radius); padding:22px 18px 14px; position:relative; box-shadow:var(--shadow-md); }
.diagram-card::before { content:''; position:absolute; top:0; left:0; right:0; height:3px; background:linear-gradient(90deg,var(--navy),var(--navy-2) 60%,var(--accent)); border-radius:var(--radius) var(--radius) 0 0; }
svg#secDiagram { width:100%; height:auto; display:block; }
svg text { font-family:var(--font-ui); font-feature-settings:'tnum'; }
.legend { display:flex; gap:16px; flex-wrap:wrap; font-size:11px; color:var(--ink-3); margin-top:10px; padding-top:10px; border-top:1px solid var(--line); }
.legend span::before { content:''; display:inline-block; width:14px; height:2px; margin-right:6px; vertical-align:middle; background:currentColor; }
.legend .lx { color:var(--c-x); } .legend .ly { color:var(--c-y); } .legend .lp { color:var(--c-p); } .legend .lc { color:var(--c-c); }
.cards { display:flex; flex-direction:column; gap:14px; }
.card { background:var(--surface); border:1px solid var(--line); border-radius:var(--radius); overflow:hidden; box-shadow:var(--shadow-sm); }
.card[data-open="true"] { border-color:var(--navy-2); box-shadow:var(--shadow-md); }
.card-header { display:flex; align-items:center; gap:13px; padding:16px 20px; }
.card-header[data-toggle] { cursor:pointer; user-select:none; }
.card-header[data-toggle]:hover { background:var(--surface-alt); }
.step-badge { width:26px; height:26px; border-radius:7px; background:var(--surface-alt); border:1px solid var(--line); display:inline-flex; align-items:center; justify-content:center; font-size:12px; font-weight:600; color:var(--ink-2); font-family:var(--font-serif); flex-shrink:0; }
.card[data-open="true"] .step-badge,.card.always-open .step-badge { background:var(--navy); color:var(--ink-inv); border-color:var(--navy); }
.card-title-block { display:flex; flex-direction:column; gap:1px; margin-right:auto; }
.card-title { font-family:var(--font-serif); font-size:16px; font-weight:600; color:var(--ink); }
.card-subtitle { font-size:11.5px; color:var(--ink-3); }
.caret { width:10px; height:10px; border-right:1.6px solid var(--ink-2); border-bottom:1.6px solid var(--ink-2); transform:rotate(45deg); transition:transform 280ms; margin-bottom:4px; margin-left:8px; }
.card[data-open="true"] .caret { transform:rotate(225deg); margin-bottom:0; margin-top:4px; }
.card-body-wrap { display:grid; grid-template-rows:0fr; transition:grid-template-rows 320ms cubic-bezier(0.4,0,0.2,1); }
.card[data-open="true"] .card-body-wrap,.card.always-open .card-body-wrap { grid-template-rows:1fr; }
.card-body-inner { overflow:hidden; }
.card-body { padding:0 20px 20px; border-top:1px solid var(--line); padding-top:18px; }
.field-grid { display:grid; gap:12px; grid-template-columns:repeat(auto-fit,minmax(150px,1fr)); }
.field-label { font-size:11px; font-weight:600; color:var(--ink-2); letter-spacing:0.06em; margin-bottom:6px; display:flex; align-items:baseline; gap:6px; text-transform:uppercase; }
.field-label em { font-family:var(--font-math); font-style:italic; font-weight:600; color:var(--ink); font-size:14px; text-transform:none; letter-spacing:0; }
.field-input { display:flex; align-items:baseline; gap:8px; padding:10px 14px; background:var(--surface); border:1px solid var(--line); border-radius:var(--radius-sm); }
.field-input:focus-within { border-color:var(--navy); box-shadow:0 0 0 3px var(--accent-soft); }
.field-input input { flex:1; border:none; background:transparent; font-family:inherit; font-size:17px; font-weight:500; color:var(--ink); outline:none; width:100%; min-width:0; -moz-appearance:textfield; }
.field-input input::-webkit-outer-spin-button,.field-input input::-webkit-inner-spin-button { -webkit-appearance:none; }
.field-unit { font-size:12px; color:var(--ink-3); font-weight:500; white-space:nowrap; }
.field-note { font-size:11.5px; color:var(--ink-3); margin-top:12px; padding:10px 14px; background:var(--surface-alt); border-radius:var(--radius-sm); line-height:1.5; }
.field-note strong { color:var(--ink-2); }
.switch-row { display:flex; gap:10px; flex-wrap:wrap; margin-top:12px; }
.switch { display:inline-flex; align-items:center; gap:8px; padding:8px 12px; border:1px solid var(--line); border-radius:var(--radius-sm); font-size:12.5px; font-weight:500; color:var(--ink-2); cursor:pointer; background:var(--surface); user-select:none; }
.switch input { accent-color:var(--navy); }
.switch.on { border-color:var(--navy); background:var(--surface-alt); color:var(--ink); }
.seg { display:inline-flex; background:var(--surface-alt); border:1px solid var(--line); border-radius:var(--radius-sm); padding:3px; gap:2px; }
.seg button { border:none; background:transparent; padding:7px 12px; font-family:inherit; font-size:12.5px; font-weight:600; color:var(--ink-3); border-radius:5px; cursor:pointer; }
.seg button.active { background:var(--navy); color:#fff; }
.results { display:grid; grid-template-columns:1fr 1fr; gap:10px; }
@media (max-width:600px) { .results { grid-template-columns:1fr; } }
.results .calc-group { grid-column:1 / -1; }
.res { padding:10px 13px; background:var(--surface-alt); border-radius:var(--radius-sm); border-left:3px solid var(--navy); display:flex; flex-direction:column; gap:3px; }
.res.minor { border-left-color:var(--line-2); }
.res.x { border-left-color:var(--c-x); } .res.y { border-left-color:var(--c-y); } .res.p { border-left-color:var(--c-p); }
.res-k { font-family:var(--font-math); font-style:italic; font-weight:600; font-size:14px; color:var(--ink); display:flex; justify-content:space-between; align-items:baseline; }
.res-k sub { font-size:10px; font-style:normal; }
.res-k .annot { font-family:var(--font-ui); font-style:normal; font-weight:400; font-size:10px; color:var(--ink-3); }
.res-v { font-weight:700; font-size:16px; color:var(--ink); font-variant-numeric:tabular-nums; }
.res-v .unit { font-size:11px; font-weight:500; color:var(--ink-3); margin-left:4px; }
.res-alt { font-size:11px; color:var(--ink-3); font-variant-numeric:tabular-nums; }
.formulas { display:flex; flex-direction:column; gap:10px; }
.formula-block { font-family:var(--font-math); font-size:14.5px; line-height:1.55; padding:10px 14px; background:var(--surface-alt); border-radius:var(--radius-sm); border-left:3px solid var(--line-2); }
.formula-block b { font-style:italic; font-weight:600; }
.frac { display:inline-flex; flex-direction:column; align-items:center; vertical-align:middle; margin:0 2px; font-size:0.88em; }
.frac .num { border-bottom:1.4px solid currentColor; padding:0 5px 1px; }
.frac .den { padding:1px 5px 0; }

/* ---- calc-row: label | formula+substitution | boxed result (matches beam report style) ---- */
.calc-group { display:flex; flex-direction:column; margin-bottom:14px; }
.calc-group:last-child { margin-bottom:0; }
.calc-group-title { font-size:10.5px; font-weight:700; letter-spacing:0.07em; text-transform:uppercase; color:var(--ink-3); margin-bottom:6px; padding-top:4px; }
.calc-row { display:grid; grid-template-columns:minmax(56px,auto) 1fr auto; gap:10px; align-items:baseline; padding:8px 0; border-bottom:1px dotted var(--line); font-family:var(--font-math); font-size:14px; }
.calc-row:last-child { border-bottom:none; }
.calc-lab { font-style:italic; font-weight:700; color:var(--ink); white-space:nowrap; }
.calc-lab sub, .calc-lab sup { font-size:10px; font-style:normal; }
.calc-lab .annot { display:block; font-family:var(--font-ui); font-style:normal; font-weight:400; font-size:9.5px; color:var(--ink-3); text-transform:none; letter-spacing:0; white-space:normal; margin-top:1px; }
.calc-expr { font-style:italic; color:var(--ink-2); line-height:1.5; overflow-wrap:break-word; }
.calc-expr .up { font-style:normal; font-family:var(--font-ui); font-size:0.78em; color:var(--ink-3); }
.calc-res { font-family:var(--font-ui); font-style:normal; font-weight:700; white-space:nowrap; background:rgba(245,184,64,0.13); border:1px solid rgba(245,184,64,0.55); padding:4px 10px; border-radius:var(--radius-xs); color:var(--ink); font-size:14px; }
.calc-res .unit { font-size:10.5px; font-weight:500; color:var(--ink-3); margin-left:3px; }
.calc-row.x .calc-res { border-color:var(--c-x); background:rgba(21,101,192,0.08); }
.calc-row.y .calc-res { border-color:var(--c-y); background:rgba(109,78,199,0.08); }
.calc-row.p .calc-res { border-color:var(--c-p); background:rgba(192,101,26,0.08); }
.calc-row.minor .calc-lab { font-weight:600; color:var(--ink-2); }
@media (max-width:520px) { .calc-row { grid-template-columns:1fr; row-gap:4px; } .calc-res { justify-self:start; } }
.parts-table { width:100%; border-collapse:collapse; font-size:12.5px; }
.parts-table th { text-align:left; font-size:10.5px; letter-spacing:0.06em; text-transform:uppercase; color:var(--ink-3); padding:6px 6px; border-bottom:1px solid var(--line); }
.parts-table td { padding:4px 4px; }
.parts-table input { width:100%; padding:7px 9px; border:1px solid var(--line); border-radius:6px; font-family:inherit; font-size:13px; color:var(--ink); outline:none; -moz-appearance:textfield; }
.parts-table input:focus { border-color:var(--navy); }
.parts-table input::-webkit-outer-spin-button,.parts-table input::-webkit-inner-spin-button { -webkit-appearance:none; }
.parts-table .del { border:none; background:transparent; color:var(--ink-3); cursor:pointer; font-size:16px; padding:4px 8px; }
.parts-table .del:hover { color:var(--c-c); }
.btn-small { display:inline-flex; align-items:center; gap:6px; padding:7px 12px; border-radius:6px; border:1px solid var(--line); background:var(--surface); color:var(--ink-2); font-family:inherit; font-size:12px; font-weight:600; cursor:pointer; margin-top:10px; }
.btn-small:hover { border-color:var(--navy); color:var(--ink); }
textarea.coords { width:100%; min-height:150px; padding:10px 12px; border:1px solid var(--line); border-radius:var(--radius-sm); font-family:'Cascadia Code','Consolas',monospace; font-size:13px; color:var(--ink); outline:none; resize:vertical; }
textarea.coords:focus { border-color:var(--navy); box-shadow:0 0 0 3px var(--accent-soft); }
.warn { color:#b45309; background:#fef3c7; border:1px solid #fcd34d; padding:8px 12px; border-radius:6px; font-size:12px; margin-top:10px; display:none; }
.appfoot { margin-top:36px; padding-top:18px; border-top:1px solid var(--line-on-dark); text-align:center; font-size:11px; color:var(--on-dark-3); }
@media print {
  @page { size:A4 portrait; margin:12mm; }
  body { padding:0; background:#fff !important; background-image:none !important; }
  .topbar-right,.appfoot { display:none !important; }
  .workspace { grid-template-columns:1fr 1fr; gap:14px; }
  .diagram-pane { position:static; }
  .diagram-card { box-shadow:none; padding:8px 4px 4px; }
  .diagram-card::before { display:none; }
  .card { box-shadow:none !important; break-inside:avoid; }
  .card-body-wrap { grid-template-rows:1fr !important; }
  .card .caret { display:none; }
}