/* Iterverse brand tokens (tokens.css/fonts.css, linked before this file)
   define --btech-*, --neutral-*, --font-sans, etc, per
   design-system/README.md in the ad_labs repo. This file's own local
   names below alias to those - --text-muted specifically uses the
   --neutral-600 primitive rather than tokens.css's own --text-muted
   semantic name, since aliasing a local var to a design-system var of
   the *same name* inside one :root block is a self-reference (CSS
   resolves it to nothing, not the tokens.css value - a real bug
   pattern hit earlier working on the labs app's own style.css). */
:root {
  --bg: var(--surface-page);
  --surface: var(--surface-card);
  --border: var(--border-subtle);
  --text: var(--text-strong);
  --text-muted: var(--neutral-600);
  --accent: var(--btech-red);
  --accent-dark: var(--btech-red-dark);
  --accent-bg: #fbe9ea;
  --good: var(--color-success);
  --good-bg: #e7f6ee;
  --bad: var(--btech-red);
  --bad-bg: #fdecea;
  --code-bg: var(--btech-gray);
  --code-text: var(--neutral-100);
  --radius: 8px;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: var(--font-sans);
  background: var(--bg);
  color: var(--text);
  line-height: 1.55;
}

a { color: var(--accent); }

/* Charcoal, not brand red, as the header surface - a full-width red band
   would read as a wash rather than the deliberate, small-proportion use
   brand.md calls for. Red stays reserved for the mark and link/accent
   states within the header instead. Matches the dark-surface header
   treatment already used on labs.iterverse.net and reader.iterverse.net. */
header.site-header {
  background: var(--btech-gray);
  color: #fff;
  padding: 1rem 1.5rem;
}

header.site-header .wrap {
  max-width: 980px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.header-brand {
  display: flex;
  align-items: center;
  gap: 0.65rem;
  text-decoration: none;
}

.header-brand img {
  height: 26px;
  width: auto;
}

.header-divider {
  width: 1px;
  height: 22px;
  background: rgba(255, 255, 255, 0.25);
}

.header-btech-mark {
  height: 22px;
  width: auto;
}

.header-wordmark {
  color: rgba(255, 255, 255, 0.62);
  font-size: 1.1rem;
  letter-spacing: -0.01em;
}
.header-wordmark strong {
  color: #fff;
  font-weight: var(--fw-bold);
}

header.site-header nav a {
  color: #fff;
  text-decoration: none;
  font-weight: 400;
  font-size: 0.95rem;
  opacity: 0.85;
  margin-left: 1rem;
}
header.site-header nav a:hover { opacity: 1; }

main {
  max-width: 980px;
  margin: 0 auto;
  padding: 1.5rem 1.5rem 4rem;
}

h1 { font-size: 1.8rem; margin-bottom: 0.25rem; }
h2 {
  font-size: 1.35rem;
  margin-top: 2.5rem;
  padding-bottom: 0.4rem;
  border-bottom: 2px solid var(--border);
}
h3 { font-size: 1.1rem; margin-top: 1.75rem; }

.subtitle { color: var(--text-muted); margin-top: 0; }

.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.25rem 1.5rem;
  margin: 1.5rem 0;
}

.lab-list { display: grid; gap: 1rem; margin-top: 1.5rem; }
.lab-card {
  display: block;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.25rem 1.5rem;
  text-decoration: none;
  color: var(--text);
  transition: border-color 0.15s, box-shadow 0.15s;
}
.lab-card:hover {
  border-color: var(--accent);
  box-shadow: var(--shadow-sm);
}
.lab-card h3 { margin: 0 0 0.35rem; color: var(--accent-dark); }
.lab-card p { margin: 0; color: var(--text-muted); font-size: 0.95rem; }
.lab-card .tag {
  display: inline-block;
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  background: var(--accent-bg);
  color: var(--accent-dark);
  padding: 0.15rem 0.5rem;
  border-radius: 4px;
  margin-bottom: 0.5rem;
}

/* Callouts */
.callout {
  border-left: 4px solid var(--accent);
  background: var(--accent-bg);
  border-radius: 0 var(--radius) var(--radius) 0;
  padding: 0.9rem 1.1rem;
  margin: 1.25rem 0;
}
/* Secondary blue, not the original purple - BTECH's approved secondary
   palette is green/blue/gold/brown, no purple. */
.callout.pt-note { border-left-color: var(--secondary-blue); background: #e8edf7; }
.callout.warn { border-left-color: var(--bad); background: var(--bad-bg); }
.callout p:first-child { margin-top: 0; }
.callout p:last-child { margin-bottom: 0; }
.callout .label {
  display: block;
  font-weight: 700;
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  margin-bottom: 0.35rem;
  color: var(--accent-dark);
}
.callout.pt-note .label { color: var(--secondary-blue); }
.callout.warn .label { color: var(--bad); }

/* Tables */
table.data {
  width: 100%;
  border-collapse: collapse;
  margin: 1rem 0;
  font-size: 0.92rem;
}
table.data th, table.data td {
  border: 1px solid var(--border);
  padding: 0.5rem 0.6rem;
  text-align: left;
  vertical-align: middle;
}
table.data th {
  background: #eef2f6;
  font-size: 0.82rem;
  text-transform: uppercase;
  letter-spacing: 0.03em;
  color: var(--text-muted);
}
table.data tbody tr:nth-child(even) { background: #fafbfc; }

table.data input[type="text"] {
  width: 100%;
  min-width: 100px;
  padding: 0.35rem 0.4rem;
  border: 1px solid var(--border);
  border-radius: 4px;
  font-family: "Consolas", monospace;
  font-size: 0.9rem;
}
table.data input.correct { border-color: var(--good); background: var(--good-bg); }
table.data input.incorrect { border-color: var(--bad); background: var(--bad-bg); }

.field-hint {
  display: block;
  margin-top: 0.3rem;
  font-size: 0.76rem;
  font-style: italic;
  color: var(--bad);
  font-family: "Segoe UI", system-ui, sans-serif;
}

/* Collapsible "Need a hint?" boxes */
details.hint-box {
  border: 1px solid var(--border);
  border-radius: var(--radius);
  margin: 1rem 0 1.5rem;
  background: #fbfdfe;
}
details.hint-box summary {
  cursor: pointer;
  padding: 0.65rem 1rem;
  font-weight: 600;
  color: var(--accent-dark);
  list-style: none;
}
details.hint-box summary::-webkit-details-marker { display: none; }
details.hint-box summary::before { content: "Hint — "; font-weight: 600; }
details.hint-box[open] summary { border-bottom: 1px solid var(--border); }
details.hint-box .hint-content { padding: 0.75rem 1rem 1rem; }
details.hint-box .hint-content p:first-child { margin-top: 0; }
details.hint-box details {
  margin-top: 0.6rem;
  padding-left: 0.75rem;
  border-left: 2px solid var(--border);
}
details.hint-box details summary {
  padding: 0.3rem 0;
  font-size: 0.9rem;
}
details.hint-box details summary::before { content: "Still stuck — "; }

.check-row {
  display: flex;
  align-items: center;
  gap: 1rem;
  margin-top: 0.75rem;
}

button.check-btn {
  background: var(--accent);
  color: #fff;
  border: none;
  padding: 0.5rem 1.1rem;
  border-radius: 6px;
  font-size: 0.9rem;
  font-weight: 600;
  cursor: pointer;
}
button.check-btn:hover { background: var(--accent-dark); }
button.check-btn.reset { background: transparent; color: var(--text-muted); border: 1px solid var(--border); }
button.check-btn.reset:hover { background: #eef2f6; }

.check-result { font-size: 0.9rem; font-weight: 600; }
.check-result.good { color: var(--good); }
.check-result.bad { color: var(--bad); }

/* Code blocks */
pre {
  background: var(--code-bg);
  color: var(--code-text);
  padding: 0.9rem 1.1rem;
  border-radius: var(--radius);
  overflow-x: auto;
  font-family: "Consolas", monospace;
  font-size: 0.88rem;
  line-height: 1.5;
}
code { font-family: "Consolas", monospace; }
:not(pre) > code {
  background: #eef2f6;
  padding: 0.1rem 0.35rem;
  border-radius: 4px;
  font-size: 0.9em;
}

/* Checklist */
ul.checklist { list-style: none; padding-left: 0; }
ul.checklist li {
  padding: 0.4rem 0;
  border-bottom: 1px dashed var(--border);
  display: flex;
  align-items: flex-start;
  gap: 0.6rem;
}
ul.checklist li:last-child { border-bottom: none; }
ul.checklist input[type="checkbox"] { margin-top: 0.25rem; }

.steps { padding-left: 1.25rem; }
.steps li { margin-bottom: 0.5rem; }

footer.site-footer {
  text-align: center;
  color: var(--text-muted);
  font-size: 0.85rem;
  padding: 2rem 1rem;
}

.scroll-x { overflow-x: auto; }

@media (max-width: 600px) {
  table.data { font-size: 0.82rem; }
}

/* Worksheet submission controls */
.id-fields {
  display: flex;
  gap: 1.5rem;
  flex-wrap: wrap;
  margin: 0.75rem 0 1rem;
}
.id-fields label {
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--text-muted);
}
.id-fields input {
  padding: 0.4rem 0.6rem;
  border: 1px solid var(--border);
  border-radius: 6px;
  font-family: inherit;
  font-size: 0.95rem;
  min-width: 220px;
}

.print-fab {
  position: fixed;
  right: 1.5rem;
  bottom: 1.5rem;
  background: var(--accent);
  color: #fff;
  border: none;
  padding: 0.75rem 1.25rem;
  border-radius: 999px;
  font-weight: 600;
  font-size: 0.9rem;
  box-shadow: var(--shadow-md);
  cursor: pointer;
  z-index: 500;
}
.print-fab:hover { background: var(--accent-dark); }

/* Print output: keep only the fillable worksheet — tables, checklist, name/date */
@media print {
  .no-print,
  header.site-header,
  footer.site-footer,
  .print-fab,
  .check-row,
  .callout,
  .field-hint,
  details.hint-box,
  pre {
    display: none !important;
  }

  body { background: #fff; }
  main { max-width: 100%; padding: 0; }

  table.data input[type="text"] {
    border: none;
    background: transparent;
    padding: 0.15rem 0;
  }
  table.data input.correct,
  table.data input.incorrect {
    border: none;
    background: transparent;
  }

  h2 { break-after: avoid; }
  table.data { break-inside: avoid; }
}