/* ============================================================
   v2-tools.css — maps the legacy tool-page components and CSS
   variables onto the v2 porcelain/petrol design system.
   Load AFTER v2.css on tool pages.
   ============================================================ */

:root {
  /* legacy variable names -> v2 values */
  --paper: #f4f6f6;
  --panel: #ffffff;
  --bg: #f4f6f6;
  --bg-2: #eceff0;
  --bg2: #eceff0;
  --panel-solid: #ffffff;
  --ink: #131619;
  --text: #131619;
  --muted: #64707a;
  --faint: #8b96a0;
  --line: #dde3e5;
  --line-strong: #c3ccd0;
  --accent: #0d6e79;
  --accent-ink: #09525b;
  --accent-bright: #0d6e79;
  --cyan: #0d6e79;
  --blue: #09525b;
  --amber: #b3541e;
  --warn: #b3541e;
  --screen: #0f1416;
  --screen-line: rgba(120, 200, 215, .14);
  --trace: #35c6d8;
  --trace-soft: rgba(53, 198, 216, .5);
  --shadow: 0 12px 34px rgba(19, 22, 25, .08);
  --radius: 2px;
  --font-display: "Fraunces", Georgia, serif;
  --font-body: "Public Sans", system-ui, sans-serif;
  --font-mono: "IBM Plex Mono", ui-monospace, Menlo, monospace;
}

body { background: var(--paper); color: var(--ink); font-family: var(--font-body); }

/* legacy fixed brand + theme toggles: replaced by v2 header */
.brand, .theme-toggle { display: none !important; }

/* ---------- shell & headings ---------- */
.shell { width: min(1200px, calc(100% - 48px)); margin: 0 auto; padding: 56px 0 90px; }

.breadcrumb { font: 500 .76rem var(--font-mono); letter-spacing: .08em; text-transform: uppercase; color: var(--faint); margin-bottom: 30px; }
.breadcrumb a { color: var(--accent-ink); text-decoration: none; }
.breadcrumb a:hover { text-decoration: underline; }
.breadcrumb span { margin: 0 8px; }

.kicker { font: 500 .78rem var(--font-mono); letter-spacing: .18em; text-transform: uppercase; color: var(--accent-ink); margin: 0 0 20px; }

.shell h1 { font-family: var(--font-display); font-weight: 480; font-size: clamp(2.1rem, 4.4vw, 3.4rem); line-height: 1.08; letter-spacing: -.02em; margin: 0 0 8px; }
.shell h2 { font-family: var(--font-display); font-weight: 520; font-size: 1.55rem; letter-spacing: -.012em; line-height: 1.2; margin: 0 0 16px; }
.shell h3 { font-family: var(--font-display); font-weight: 560; font-size: 1.16rem; margin: 0 0 8px; }

.intro { max-width: 70ch; color: var(--muted); font-size: 1.05rem; line-height: 1.7; margin: 16px 0 0; }
.section { margin-top: 64px; }
.explain { max-width: 72ch; }
.explain .aside, .aside { color: var(--muted); font-size: .93rem; }

.trace-divider { display: none; }

/* ---------- cards ---------- */
.card-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(280px, 1fr)); gap: 14px; }
.card, .tool-card {
  display: flex; flex-direction: column; justify-content: space-between; gap: 14px;
  border: 1px solid var(--line-strong); background: var(--panel);
  padding: 24px; color: inherit; text-decoration: none;
  transition: border-color .25s, transform .25s;
}
a.card:hover, a.tool-card:hover { border-color: var(--accent); transform: translateY(-2px); }
.card p, .tool-card p { margin: 0; color: var(--muted); font-size: .93rem; }
.card ul { margin: 10px 0 0; padding-left: 18px; color: var(--muted); font-size: .9rem; }
.tool-card .open { font: 500 .74rem var(--font-mono); letter-spacing: .12em; text-transform: uppercase; color: var(--accent-ink); }

.note, .lesson {
  margin-top: 48px; border: 1px solid var(--line); border-left: 2px solid var(--amber);
  background: var(--panel); color: var(--muted); padding: 20px 24px; font-size: .95rem; max-width: 80ch;
}
.lesson h2 { font-size: 1.2rem; color: var(--ink); }

/* ---------- calculator components ---------- */
.tool-layout { display: grid; grid-template-columns: 340px 1fr; gap: 22px; align-items: start; margin-top: 56px; }
@media (max-width: 900px){ .tool-layout { grid-template-columns: 1fr; } }

.panel { border: 1px solid var(--line-strong); background: var(--panel); padding: 24px; }
.panel h2 { font-size: 1.18rem; margin-bottom: 16px; }
.tool-layout > * { min-width: 0; }

.field { display: grid; min-width: 0; gap: 6px; margin-bottom: 16px; }
.field label { font: 500 .72rem var(--font-mono); letter-spacing: .08em; text-transform: uppercase; color: var(--muted); }
.field .row { display: grid; grid-template-columns: 1fr auto; gap: 8px; }
.field input[type="number"], .field input[type="text"], .field select {
  width: 100%; min-width: 0; max-width: 100%; padding: 10px 12px; border: 1px solid var(--line-strong); border-radius: 0;
  background: var(--paper); color: var(--ink); font: 500 .95rem var(--font-mono);
}
.field input:focus, .field select:focus { outline: 2px solid var(--accent); outline-offset: 1px; }
.field input[type="range"] { width: 100%; accent-color: var(--accent); }
.field .unit-select { min-width: 88px; }
.field small { color: var(--faint); font-size: .78rem; font-family: var(--font-body); text-transform: none; letter-spacing: 0; }

.results { display: grid; gap: 10px; }
.result-row { display: flex; justify-content: space-between; align-items: baseline; gap: 12px; border-bottom: 1px solid var(--line); padding-bottom: 9px; }
.result-row:last-child { border-bottom: 0; }
.result-row .rlabel { color: var(--muted); font-size: .9rem; }
.result-row .rvalue {
  min-width: 0; font: 500 1.02rem var(--font-mono); color: var(--accent-ink);
  text-align: right; white-space: normal; overflow-wrap: anywhere;
}
.result-row .rvalue.big { font-size: 1.55rem; }

.formula {
  font: 500 .96rem var(--font-mono); color: var(--ink);
  border: 1px solid var(--line); border-left: 2px solid var(--accent);
  background: var(--panel); padding: 16px 18px; margin: 18px 0; overflow-x: auto; max-width: 80ch;
}

.viz { border: 1px solid var(--line-strong); background: var(--screen); padding: 10px; }
.panel + .viz, .viz + .panel { margin-top: 22px; }
.tool-layout .viz:first-child { margin-top: 0; }
.viz + .aside, .viz + .explain { margin-top: 12px; }
.viz svg, .viz canvas { display: block; width: 100%; height: auto; }

table.data { width: 100%; border-collapse: collapse; font-size: .88rem; }
table.data th { text-align: left; font: 500 .7rem var(--font-mono); letter-spacing: .08em; color: var(--muted); text-transform: uppercase; padding: 8px 10px; border-bottom: 1px solid var(--line-strong); }
table.data td { padding: 8px 10px; border-bottom: 1px solid var(--line); font-family: var(--font-mono); font-size: .86rem; }

.btn {
  border: 1px solid var(--ink); background: transparent; color: var(--ink);
  font: 500 .76rem var(--font-mono); letter-spacing: .1em; text-transform: uppercase;
  padding: 10px 16px; cursor: pointer; border-radius: 0; transition: background .2s, color .2s;
}
.btn:hover { background: var(--ink); color: var(--paper); }

.report-actions {
  display: flex; align-items: center; justify-content: flex-end; gap: 12px;
  grid-column: 1 / -1; width: 100%;
  margin-top: 18px; padding-top: 16px; border-top: 1px solid var(--line);
}
.report-actions .report-status { color: var(--muted); font-size: .8rem; }

/* legacy site-footer on migrated pages */
.site-footer { border-top: 1px solid var(--line-strong); background: var(--bg-2); margin-top: 50px; }
.site-footer .bar {
  width: min(1200px, calc(100% - 48px)); margin: 0 auto; padding: 26px 0 36px;
  display: flex; justify-content: space-between; gap: 12px; flex-wrap: wrap;
  font: 500 .76rem var(--font-mono); letter-spacing: .06em; color: var(--muted);
}
.site-footer a { color: var(--muted); text-decoration: none; }
.site-footer a:hover { color: var(--ink); }

:focus-visible { outline: 2px solid var(--accent); outline-offset: 3px; }


/* tool pages: kill v2.css's 96px section padding; margins alone set the rhythm */
.shell section:not(.panel) { padding: 0; }
.shell .section:first-of-type { margin-top: 56px; }

/* ---------- maths rendering ---------- */
.formula { font: 500 1.02rem var(--font-mono); line-height: 1.5; padding: 20px 22px; margin: 22px 0; }
.formula .eq { display: inline-flex; align-items: center; gap: 10px; flex-wrap: wrap; }
.frac { display: inline-flex; flex-direction: column; align-items: stretch; vertical-align: middle; margin: 0 4px; }
.frac > span { display: block; padding: 1px 10px; text-align: center; white-space: nowrap; }
.frac > span:first-child { border-bottom: 1.5px solid currentColor; }
.sqrtc, .eq .rad + .vinc { }
.rad { font-size: 2.15em; line-height: .82; align-self: stretch; display: inline-flex; align-items: flex-start; margin-right: -0.14em; transform: translateY(0.045em); }
.rad sup { font-size: .4em; align-self: flex-start; margin-top: .1em; margin-right: -.15em; }
.vinc { border-top: 2px solid currentColor; padding: 6px 10px 2px; display: inline-flex; align-items: center; }
.formula sub, .formula sup { font-size: .72em; }
.formula .where { display: block; margin-top: 12px; font-size: .86rem; color: var(--muted); }

@media (max-width: 560px) {
  .shell { width: min(100% - 28px, 1200px); }
  .panel { padding: 18px; }
  .result-row { align-items: flex-start; }
  .result-row .rvalue { max-width: 58%; }
  .report-actions { justify-content: flex-start; flex-wrap: wrap; }
}