/* NeckTraining.com — clean editorial reference
   No JS. No webfonts. No layout shift. Readable at any width.
   Colour is carried almost entirely by neutrals; one accent, used sparingly. */

:root {
  --ink:        #16181d;
  --ink-soft:   #4a4f5a;
  --ink-faint:  #767c88;
  --rule:       #dfe1e6;
  --rule-soft:  #eceef1;
  --paper:      #ffffff;
  --paper-warm: #f7f6f3;
  --accent:     #7a2417;   /* oxblood — links, marks */
  --measure:    38rem;

  --serif: Charter, "Bitstream Charter", "Sitka Text", Cambria, Georgia, serif;
  --sans:  system-ui, -apple-system, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --mono:  ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, monospace;
}

@media (prefers-color-scheme: dark) {
  :root {
    --ink:        #e6e7ea;
    --ink-soft:   #b0b4bd;
    --ink-faint:  #868b95;
    --rule:       #33373f;
    --rule-soft:  #262a31;
    --paper:      #14161a;
    --paper-warm: #1b1e23;
    --accent:     #e0836f;
  }
}

*, *::before, *::after { box-sizing: border-box; }

html { -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--serif);
  font-size: 1.125rem;
  line-height: 1.65;
  text-rendering: optimizeLegibility;
}

.wrap {
  width: 100%;
  max-width: 64rem;
  margin-inline: auto;
  padding-inline: 1.5rem;
}

.skip {
  position: absolute; left: -9999px;
  background: var(--ink); color: var(--paper);
  padding: .75rem 1rem; z-index: 10;
}
.skip:focus { left: 1rem; top: 1rem; }

/* ---------- header ---------- */

.site-header {
  border-bottom: 1px solid var(--rule);
  background: var(--paper);
  padding-block: 1rem;
}
.site-header .wrap {
  display: flex; flex-wrap: wrap; gap: .75rem 2rem;
  align-items: baseline; justify-content: space-between;
}
.wordmark {
  font-family: var(--serif);
  font-size: 1.3rem; font-weight: 700;
  letter-spacing: -.01em;
  color: var(--ink); text-decoration: none;
}
.wordmark span { color: var(--ink-faint); font-weight: 400; }

.site-header nav {
  display: flex; flex-wrap: wrap; gap: 1.15rem;
  font-family: var(--sans); font-size: .875rem;
}
.site-header nav a {
  color: var(--ink-soft); text-decoration: none;
  border-bottom: 1px solid transparent; padding-bottom: 1px;
}
.site-header nav a:hover { color: var(--accent); border-bottom-color: currentColor; }

/* ---------- page ---------- */

main { padding-block: 2.5rem 4rem; }
/* Article pages read in a single balanced column rather than hugging the left
   edge of a wide grid. Header and footer keep the full 64rem measure. */
main > .wrap { max-width: 48rem; }

.breadcrumb {
  font-family: var(--sans); font-size: .8125rem;
  color: var(--ink-faint); margin-bottom: 1.75rem;
}
.breadcrumb a { color: var(--ink-faint); }
.breadcrumb span { padding-inline: .4rem; }

.page { max-width: var(--measure); }
.page.wide { max-width: none; }

.page-head { margin-bottom: 2rem; }

h1 {
  font-size: clamp(1.9rem, 1.3rem + 2.4vw, 2.85rem);
  line-height: 1.12;
  letter-spacing: -.02em;
  font-weight: 700;
  margin: 0 0 .5rem;
  text-wrap: balance;
}
.subtitle {
  font-size: 1.2rem; color: var(--ink-soft);
  margin: 0; line-height: 1.45; text-wrap: pretty;
}

h2 {
  font-size: 1.5rem; line-height: 1.25; letter-spacing: -.011em;
  margin: 3rem 0 .85rem; text-wrap: balance;
}
h3 {
  font-size: 1.175rem; line-height: 1.3;
  margin: 2.25rem 0 .6rem; text-wrap: balance;
}
h4 {
  font-family: var(--sans); font-size: .8125rem;
  text-transform: uppercase; letter-spacing: .08em;
  color: var(--ink-faint); font-weight: 600;
  margin: 2rem 0 .5rem;
}

p, ul, ol { margin: 0 0 1.15rem; }
li { margin-bottom: .35rem; }
li > ul, li > ol { margin-top: .35rem; }

a { color: var(--accent); text-decoration-thickness: 1px; text-underline-offset: 2px; }
a:hover { text-decoration-thickness: 2px; }

strong { font-weight: 700; }

/* ---------- the answer block: the paragraph an LLM lifts ---------- */

.answer {
  border-left: 3px solid var(--accent);
  background: var(--paper-warm);
  padding: 1.15rem 1.35rem;
  margin: 0 0 2.25rem;
  font-size: 1.1rem;
  line-height: 1.55;
}
.answer p { margin: 0; }
.answer p + p { margin-top: .75rem; }

/* ---------- primary source quotation ---------- */

blockquote {
  margin: 1.75rem 0;
  padding-left: 1.25rem;
  border-left: 2px solid var(--rule);
  color: var(--ink-soft);
  font-style: italic;
}
blockquote p:last-child { margin-bottom: 0; }

.source-note {
  font-family: var(--sans); font-size: .8125rem;
  color: var(--ink-faint);
  margin: -1.35rem 0 1.75rem 1.25rem;
}

figure { margin: 2rem 0; }
figure svg, figure img { max-width: 100%; height: auto; display: block; }
figcaption {
  font-family: var(--sans); font-size: .8125rem;
  color: var(--ink-faint); margin-top: .6rem; line-height: 1.5;
}

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

.table-scroll { overflow-x: auto; margin: 1.75rem 0; }
table {
  border-collapse: collapse; width: 100%;
  font-family: var(--sans); font-size: .875rem;
  line-height: 1.45;
}
th, td {
  text-align: left; vertical-align: top;
  padding: .6rem .85rem .6rem 0;
  border-bottom: 1px solid var(--rule-soft);
}
th {
  font-weight: 600; font-size: .75rem;
  text-transform: uppercase; letter-spacing: .06em;
  color: var(--ink-faint);
  border-bottom: 1px solid var(--rule);
}

code, kbd { font-family: var(--mono); font-size: .875em; }

hr { border: 0; border-top: 1px solid var(--rule); margin: 3rem 0; }

/* ---------- hub index cards ---------- */

.index-grid {
  display: grid; gap: 1px;
  grid-template-columns: repeat(auto-fill, minmax(17rem, 1fr));
  background: var(--rule-soft);
  border: 1px solid var(--rule-soft);
  margin: 2rem 0;
}
.index-grid > a {
  background: var(--paper);
  padding: 1.15rem 1.25rem;
  text-decoration: none; color: inherit;
  display: block;
}
.index-grid > a:hover { background: var(--paper-warm); }
.index-grid h3 {
  margin: 0 0 .3rem; font-size: 1.0625rem;
  color: var(--accent);
}
.index-grid p {
  margin: 0; font-family: var(--sans);
  font-size: .875rem; line-height: 1.5; color: var(--ink-soft);
}

/* ---------- sources & related ---------- */

.sources, .related {
  margin-top: 3.5rem; padding-top: 1.5rem;
  border-top: 1px solid var(--rule);
  font-family: var(--sans); font-size: .875rem; line-height: 1.55;
}
.sources h2, .related h2 {
  font-size: .75rem; text-transform: uppercase; letter-spacing: .08em;
  color: var(--ink-faint); font-weight: 600; margin: 0 0 .85rem;
}
.sources ol { padding-left: 1.25rem; }
.sources li { margin-bottom: .6rem; }
.related ul { list-style: none; padding: 0; }
.related li { margin-bottom: .4rem; }

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

.site-footer {
  border-top: 1px solid var(--rule);
  background: var(--paper-warm);
  padding-block: 2.5rem 3rem;
  font-family: var(--sans); font-size: .875rem;
  color: var(--ink-soft);
}
.foot-cols {
  display: grid; gap: 1.75rem;
  grid-template-columns: repeat(auto-fit, minmax(14rem, 1fr));
  margin-bottom: 2rem;
}
.site-footer h2 {
  font-size: .75rem; text-transform: uppercase; letter-spacing: .08em;
  color: var(--ink-faint); font-weight: 600; margin: 0 0 .6rem;
}
.site-footer p { margin: 0 0 .75rem; line-height: 1.55; }
.site-footer ul { list-style: none; padding: 0; margin: 0; }
.site-footer li { margin-bottom: .3rem; }

.disclosure, .medical {
  max-width: 46rem;
  padding-top: 1.25rem;
  border-top: 1px solid var(--rule);
  font-size: .8125rem;
}
.medical { color: var(--ink-faint); border-top: 0; padding-top: 0; }
.copyright { font-size: .8125rem; color: var(--ink-faint); margin-top: 1.25rem; }

@media print {
  .site-header nav, .related, .skip { display: none; }
  body { font-size: 11pt; }
  a { color: inherit; text-decoration: underline; }
}

/* ---------- store call to action ---------- */

.cta {
  max-width: 46rem;
  padding: 1rem 1.15rem;
  margin-bottom: 1.5rem;
  background: var(--paper);
  border: 1px solid var(--rule);
  border-left: 3px solid var(--accent);
  font-size: .875rem;
  line-height: 1.55;
}
.cta strong { color: var(--ink); }
.cta a { font-weight: 600; white-space: nowrap; }