/* ============================================================
   nb-print.css — Numberbender print stylesheet
   Loaded with media="print", so it never touches screen rendering.

   Teachers print these pages for classrooms that have no devices.
   The printout has to be readable on paper AND carry the source, so
   a photocopied sheet still tells the next teacher where it came from.
   ============================================================ */

@page {
  size: Letter;
  margin: 0.5in;
}

/* ── strip the interface ───────────────────────────────────── */
header.nav,
.nav-links,
.menu-toggle,
.nav-dropdown,
.nav-studio-dd,
.nb-sw,
.skip-link,
footer,
#nb-sticky-bar,
.nbshare,
.nbdc,
.nbtm,
.lang-toggle,
.nbprint-btn,
.video-modal,
.vframe,
.video-slot,
.video-wrap,
.vp-icon,
.lesson-play,
iframe,
video,
audio,
button,
[role="button"],
.hero-art,
.noprint {
  display: none !important;
}

/* ── page basics ───────────────────────────────────────────── */
html, body {
  background: #fff !important;
  color: #000 !important;
  font-size: 11.5pt;
  line-height: 1.45;
}
body { margin: 0 !important; padding: 0 !important; }
main, .container, .content, section, article, div {
  background: transparent !important;
  box-shadow: none !important;
  float: none !important;
  width: auto !important;
  max-width: 100% !important;
}
main { padding: 0 !important; margin: 0 !important; }

/* keep gradients and dark panels from eating a print cartridge */
[style*="gradient"], [style*="background:#0"], [style*="background: #0"] {
  background: #fff !important;
  color: #000 !important;
  border: 1px solid #999 !important;
}

/* ── typography ────────────────────────────────────────────── */
h1, h2, h3, h4 {
  color: #000 !important;
  page-break-after: avoid;
  break-after: avoid;
}
h1 { font-size: 19pt; margin: 0 0 6pt; }
h2 { font-size: 14.5pt; margin: 14pt 0 5pt; }
h3 { font-size: 12.5pt; margin: 11pt 0 4pt; }
p, li, td, th { color: #000 !important; orphans: 3; widows: 3; }
a { color: #000 !important; text-decoration: none !important; }

/* worked solutions: never split a step across pages */
.step, .solved-step, .lesson, .acc, figure, table, pre, blockquote {
  page-break-inside: avoid;
  break-inside: avoid;
}
.math, code, pre {
  font-family: "Georgia", "Times New Roman", serif;
  background: #f4f4f4 !important;
  border: 1px solid #ddd !important;
  color: #000 !important;
}

table { border-collapse: collapse !important; width: 100% !important; }
th, td { border: 1px solid #999 !important; padding: 4pt 6pt !important; }
th { background: #eee !important; }

img { max-width: 100% !important; page-break-inside: avoid; }

/* ── the part that travels ─────────────────────────────────── */
/* A print-only source line. A photocopy of a photocopy still says
   where to find the rest of it — the same job the worksheet PDFs do. */
.nbprint-src {
  display: block !important;
  margin-top: 16pt;
  padding-top: 7pt;
  border-top: 1.5px solid #000;
  font-size: 9pt;
  line-height: 1.4;
  color: #000 !important;
  page-break-inside: avoid;
}
.nbprint-src::before {
  content: "Numberbender · Free bilingual math for teachers and students";
  display: block;
  font-weight: bold;
}
.nbprint-src::after {
  content: attr(data-url) " · Free to print and share (CC BY 4.0) · Math is hard. So we made it human.";
  display: block;
}
/* Note: this whole file is loaded with media="print", so nothing here
   applies on screen. The .nbprint-src div is empty in the HTML — its
   text comes from the ::before/::after above — so on screen it renders
   nothing at all and needs no hiding rule. */