/* ─────────────────────────────────────────────────────────────────────────
   TandemLink marketing site — shared styles.
   Design system in one file. Each HTML page is just structure + copy.

   Palette intentionally close to the en-ht-admin-portal so the
   product-side identity feels family-related to the portal a buyer's
   firm logs into. Adjust the --accent / --fg variables to reskin.
   ───────────────────────────────────────────────────────────────────────── */

/* IBM Plex Sans — the brand typeface (portfolio, 2026-07-05). Self-hosted
   variable woff2 (latin subset, from @fontsource) — no font CDN, no
   third-party call. Older browsers fall back to the system stack. */
@font-face {
  font-family: "IBM Plex Sans Variable";
  font-style: normal;
  font-display: swap;
  font-weight: 100 700;
  src: url("fonts/ibm-plex-sans-latin-wght-normal.woff2") format("woff2-variations");
}
@font-face {
  font-family: "IBM Plex Mono";
  font-style: normal;
  font-display: swap;
  font-weight: 400;
  src: url("fonts/ibm-plex-mono-latin-400-normal.woff2") format("woff2");
}
@font-face {
  font-family: "IBM Plex Mono";
  font-style: normal;
  font-display: swap;
  font-weight: 600;
  src: url("fonts/ibm-plex-mono-latin-600-normal.woff2") format("woff2");
}

:root {
  --fg:           #1b2a4a;   /* Tandem Navy — body text (portfolio-reconciled, was charcoal) */
  --fg-strong:    #1b2a4a;   /* TandemLink logo navy — headings */
  --muted:        #6b7280;
  --muted-soft:   #9ca3af;
  --accent:       #12a594;   /* TandemLink logo teal */
  --accent-hover: #0e857a;   /* darker teal (hover) */
  --accent-soft:  #e7f5f2;   /* teal tint (brand-portfolio reconciled) */
  --bg:           #ffffff;
  --bg-alt:       #f9fafb;
  --bg-dark:      #1b2a4a;   /* TandemLink logo navy — dark surfaces */
  --ink:          #0f1c33;   /* deepest dark surface (feature strip, per portfolio) */
  --slate:        #5a6b7b;   /* softened body text (portfolio palette) */
  --mono:         "IBM Plex Mono", ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  --rule:         #e5e7eb;
  --max-content:  1100px;
  --max-prose:    680px;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  background: var(--bg);
  color: var(--fg);
  font-family: "IBM Plex Sans Variable", -apple-system, BlinkMacSystemFont,
               "Segoe UI", Roboto, Oxygen, Ubuntu, Cantarell,
               "Helvetica Neue", Arial, sans-serif;
  font-size: 17px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

a {
  color: var(--accent);
  text-decoration: none;
}
a:hover { color: var(--accent-hover); text-decoration: underline; }

p { margin: 0 0 16px; }

ul { margin: 0 0 16px; padding: 0 0 0 22px; }
li { margin-bottom: 8px; }

h1, h2, h3 {
  color: var(--fg-strong);
  margin: 0 0 16px;
  letter-spacing: -0.01em;
}
h1 { font-size: 42px; line-height: 1.15; font-weight: 700; }
h2 { font-size: 26px; line-height: 1.25; font-weight: 700; }
h3 { font-size: 18px; line-height: 1.35; font-weight: 700; }

/* ── Layout containers ───────────────────────────────────────────────── */
.container {
  max-width: var(--max-content);
  margin: 0 auto;
  padding: 0 28px;
}
.prose {
  max-width: var(--max-prose);
  margin: 0 auto;
}

/* ── Top nav ──────────────────────────────────────────────────────────── */
nav.top {
  border-bottom: 1px solid var(--rule);
  background: rgba(255,255,255,0.94);
  backdrop-filter: blur(8px);
  position: sticky;
  top: 0;
  z-index: 10;
}
nav.top .inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 14px 0;
}
.wordmark {
  font-weight: 800;
  font-size: 18px;
  color: var(--fg-strong);
  letter-spacing: -0.02em;
}
.wordmark a { color: inherit; display: inline-block; }
.wordmark a:hover { text-decoration: none; color: var(--accent); }
.wordmark img { height: 26px; width: auto; display: block; }
nav.top ul.links {
  display: flex;
  gap: 26px;
  list-style: none;
  padding: 0;
  margin: 0;
  align-items: center;
}
nav.top ul.links a {
  color: var(--fg);
  font-weight: 500;
  font-size: 15px;
}
nav.top ul.links a.current {
  color: var(--accent);
}
nav.top ul.links a:hover { text-decoration: none; color: var(--accent); }

/* Contact = the nav's CTA, rendered as a teal button (portfolio site header) */
nav.top ul.links li:last-child a {
  background: var(--accent);
  color: #fff;
  font-weight: 600;
  font-size: 14px;
  padding: 9px 16px;
  border-radius: 8px;
}
nav.top ul.links li:last-child a:hover,
nav.top ul.links li:last-child a.current {
  background: var(--accent-hover);
  color: #fff;
}

/* ── Hero (home page — portfolio treatment: left-aligned, gradient,
      eyebrow pill, dual CTA) ──────────────────────────────────────────── */
.hero {
  padding: 84px 0 72px;
  text-align: left;
  background: linear-gradient(180deg, #ffffff 0%, #f3f6f9 100%);
}
.hero h1 {
  max-width: 640px;
  font-size: 46px;
  font-weight: 600;
  letter-spacing: -0.025em;
  line-height: 1.08;
  margin: 0 0 18px;
}
.hero .subhead {
  font-size: 17px;
  color: var(--slate);
  max-width: 540px;
  margin: 0 0 28px;
}
.eyebrow-pill {
  display: inline-block;
  background: var(--accent-soft);
  color: var(--accent-hover);
  font-family: var(--mono);
  font-size: 12px;
  font-weight: 600;
  padding: 6px 14px;
  border-radius: 20px;
  margin: 0 0 20px;
}
.cta-row {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
  margin: 0;
}

/* ── Page headers (about/features/support/etc) ───────────────────────── */
.pagehead {
  padding: 72px 0 32px;
  text-align: left;
}
.pagehead .eyebrow {
  display: inline-block;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  font-family: var(--mono);
  font-size: 12px;
  font-weight: 600;
  color: var(--accent-hover);
  background: var(--accent-soft);
  padding: 6px 13px;
  border-radius: 20px;
  margin-bottom: 16px;
}
.pagehead h1 {
  font-size: 44px;
  font-weight: 700;
  letter-spacing: -0.02em;
  line-height: 1.08;
  margin-bottom: 14px;
}
.pagehead .lede {
  font-size: 19px;
  color: var(--muted);
  max-width: var(--max-prose);
  margin: 0;
}

/* ── Buttons ─────────────────────────────────────────────────────────── */
.btn {
  display: inline-block;
  background: var(--accent);
  color: #fff !important;
  font-weight: 600;
  padding: 13px 24px;
  border-radius: 8px;
  font-size: 16px;
  transition: background-color 0.15s ease, transform 0.05s ease;
}
.btn:hover {
  background: var(--accent-hover);
  text-decoration: none;
  color: #fff !important;
}
.btn:active { transform: translateY(1px); }

.btn.ghost {
  background: transparent;
  color: var(--fg-strong) !important;
  border: 1px solid var(--rule);
}
.btn.ghost:hover { background: var(--bg-alt); color: var(--fg-strong) !important; }

/* ── Section ─────────────────────────────────────────────────────────── */
section {
  padding: 64px 0;
}
section.alt {
  background: var(--bg-alt);
  border-top: 1px solid var(--rule);
  border-bottom: 1px solid var(--rule);
}
section h2 { margin-bottom: 24px; }
section .lede {
  font-size: 19px;
  color: var(--muted);
  max-width: var(--max-prose);
  margin: 0 0 32px;
}

/* ── Dark feature strip (portfolio: Ink surface, teal glyph chips) ───── */
section.strip-dark {
  background: var(--ink);
  border: none;
}
section.strip-dark h2 { color: #fff; }
section.strip-dark .lede { color: #9fb0c4; }
.strip-dark .feature {
  background: transparent;
  border: none;
  padding: 0;
}
.strip-dark .feature h3 { color: #fff; font-size: 16px; }
.strip-dark .feature p  { color: #9fb0c4; font-size: 14.5px; line-height: 1.55; }
.glyph {
  width: 34px;
  height: 34px;
  border-radius: 9px;
  background: rgba(18, 165, 148, 0.18);
  color: #3ed9c4;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  margin-bottom: 10px;
}

/* ── Inset Ink card (inner-page strips + CTA cards, per site-update) ─── */
.ink-card {
  background: var(--ink);
  border-radius: 16px;
  padding: 40px 36px;
}
.ink-card .feature { background: transparent; border: none; padding: 0; }
.ink-card .feature h3 { color: #fff; font-size: 16px; margin-bottom: 4px; }
.ink-card .feature p  { color: #9fb0c4; font-size: 14px; line-height: 1.55; }
.ink-card .kicker {
  font-family: var(--mono);
  font-size: 11px;
  color: var(--accent);
  letter-spacing: 0.1em;
  text-transform: uppercase;
}
.ink-card h2, .ink-card h3 { color: #fff; }
.ink-card p { color: #9fb0c4; }

/* Navy full-width CTA bar (features footer) */
.cta-bar {
  background: var(--bg-dark);
  padding: 30px 0;
}
.cta-bar .inner-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 16px;
}
.cta-bar .line { color: #fff; font-weight: 600; font-size: 17px; }

/* White glyph cards (feature/posture/principle grids) */
.card {
  background: #fff;
  border: 1px solid var(--rule);
  border-radius: 14px;
  padding: 24px;
}
.card .num {
  font-family: var(--mono);
  font-size: 11px;
  color: var(--accent);
  display: block;
  margin-bottom: 6px;
}
.card h3 { font-size: 16px; margin-bottom: 6px; }
.card p  { font-size: 13.5px; color: var(--slate); line-height: 1.55; margin: 0; }
.card.tint {
  background: var(--accent-soft);
  border-color: #bfe6de;
}
.card.tint h3 { color: var(--accent-hover); }
.card.tint p  { color: #3f6b63; }
.glyph-lg {
  width: 40px;
  height: 40px;
  border-radius: 11px;
  background: var(--accent-soft);
  color: var(--accent-hover);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 19px;
  margin-bottom: 10px;
}

/* Check list (pricing "everything, every plan") */
.check-list { display: flex; flex-direction: column; gap: 12px; }
.check-list .row { display: flex; gap: 11px; align-items: flex-start; }
.check-list .row .tick { color: var(--accent); font-size: 16px; line-height: 1.4; }
.check-list .row span:last-child { font-size: 14.5px; color: #3a4a5f; line-height: 1.5; }

/* Two-column split grids on inner pages */
.grid-2 { display: grid; grid-template-columns: repeat(2, 1fr); gap: 16px; }
.split-2 { display: grid; grid-template-columns: 1.25fr 1fr; gap: 20px; align-items: start; }

/* ── Feature grid (3-column) ─────────────────────────────────────────── */
.grid-3 {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
}
.feature {
  padding: 28px;
  background: #fff;
  border: 1px solid var(--rule);
  border-radius: 12px;
}
.feature h3 {
  font-size: 17px;
  margin-bottom: 8px;
  color: var(--fg-strong);
}
.feature p {
  color: var(--muted);
  font-size: 15px;
  margin: 0;
}

/* ── How-it-works (numbered steps) ───────────────────────────────────── */
.steps {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
  margin-top: 16px;
}
.step .num {
  display: inline-block;
  width: 32px;
  height: 32px;
  line-height: 32px;
  text-align: center;
  background: var(--accent-soft);
  color: var(--accent-hover);
  border-radius: 50%;
  font-weight: 700;
  font-size: 14px;
  margin-bottom: 12px;
}
.step h3 {
  font-size: 17px;
  margin-bottom: 6px;
}
.step p {
  color: var(--muted);
  font-size: 15px;
  margin: 0;
}

/* ── FAQ ─────────────────────────────────────────────────────────────── */
.faq {
  border-top: 1px solid var(--rule);
}
.faq details {
  border-bottom: 1px solid var(--rule);
  padding: 18px 0;
}
.faq summary {
  cursor: pointer;
  font-weight: 600;
  font-size: 16px;
  color: var(--fg-strong);
  list-style: none;
  position: relative;
  padding-right: 28px;
}
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after {
  content: "+";
  position: absolute;
  right: 4px;
  top: -2px;
  font-size: 22px;
  font-weight: 400;
  color: var(--muted);
  transition: transform 0.15s ease;
}
.faq details[open] summary::after { content: "−"; }
.faq details p {
  margin-top: 12px;
  color: var(--muted);
}

/* ── Contact card ────────────────────────────────────────────────────── */
.contact-card {
  background: var(--bg-alt);
  border: 1px solid var(--rule);
  border-radius: 12px;
  padding: 32px;
  text-align: center;
  margin-top: 24px;
}
.contact-card h3 { font-size: 20px; margin-bottom: 8px; }
.contact-card p  { color: var(--muted); margin-bottom: 20px; }

/* ── Legal pages (privacy / terms) ───────────────────────────────────── */
.legal h2 {
  font-size: 20px;
  margin-top: 40px;
  margin-bottom: 12px;
}
.legal h3 {
  font-size: 16px;
  margin-top: 24px;
  margin-bottom: 8px;
}
.legal p, .legal li {
  color: var(--fg);
  font-size: 16px;
}
.legal .meta {
  color: var(--muted);
  font-size: 14px;
  margin-bottom: 32px;
}

/* ── Footer ──────────────────────────────────────────────────────────── */
footer.site {
  background: var(--bg-dark);
  color: #cbd5e1;
  margin-top: 0;
  padding: 56px 0 40px;
}
footer.site a { color: #e2e8f0; }
footer.site a:hover { color: #fff; }
footer.site .grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: 40px;
  margin-bottom: 40px;
}
footer.site .brand-block .wordmark { color: #fff; font-size: 20px; }
footer.site .brand-block p {
  color: #94a3b8;
  font-size: 14px;
  margin-top: 12px;
  max-width: 320px;
}
footer.site h4 {
  color: #fff;
  font-size: 13px;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin: 0 0 14px;
}
footer.site ul {
  list-style: none;
  margin: 0;
  padding: 0;
}
footer.site ul li { margin-bottom: 8px; }
footer.site ul a {
  font-size: 15px;
  color: #cbd5e1;
}
footer.site .legal-row {
  border-top: 1px solid #1e293b;
  padding-top: 24px;
  display: flex;
  justify-content: space-between;
  font-size: 13px;
  color: #94a3b8;
}
footer.site .legal-row a { color: #94a3b8; }
footer.site .provisional {
  color: #64748b;
  font-size: 12px;
  font-style: italic;
  margin-top: 6px;
}

/* ── ROI calculator (pricing page) ───────────────────────────────────── */
.roi-calc {
  display: grid;
  grid-template-columns: 380px 1fr;
  gap: 20px;
  align-items: stretch;
}
.roi-inputs {
  background: #fff;
  border: 1px solid var(--rule);
  border-radius: 14px;
  padding: 26px;
}
.roi-field { margin-bottom: 18px; }
.roi-field:last-child { margin-bottom: 0; }
.roi-field label {
  display: block;
  font-size: 13.5px;
  font-weight: 600;
  color: var(--fg-strong);
  margin-bottom: 6px;
}
.roi-field input {
  width: 100%;
  padding: 10px 12px;
  border: 1px solid var(--rule);
  border-radius: 8px;
  font: inherit;
  font-size: 16px;
  color: var(--fg-strong);
  background: var(--bg-alt);
  font-variant-numeric: tabular-nums;
}
.roi-field input:focus {
  outline: 2px solid var(--accent);
  outline-offset: 1px;
  border-color: var(--accent);
  background: #fff;
}
.roi-field .hint {
  font-size: 12px;
  color: var(--muted);
  line-height: 1.45;
  margin-top: 5px;
}
.roi-right { display: flex; flex-direction: column; gap: 16px; }
.roi-stats {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
  flex: 1;
}
.roi-stat {
  background: #fff;
  border: 1px solid var(--rule);
  border-radius: 14px;
  padding: 18px 20px;
}
.roi-stat .k {
  font-family: var(--mono, ui-monospace, SFMono-Regular, Menlo, Consolas, monospace);
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 8px;
}
.roi-stat .v {
  font-size: 25px;
  font-weight: 700;
  color: var(--fg-strong);
  letter-spacing: -0.01em;
  font-variant-numeric: tabular-nums;
  margin-bottom: 6px;
}
.roi-stat .s { font-size: 12.5px; color: var(--muted); line-height: 1.5; }
.roi-stat .s b { color: var(--fg-strong); }
.roi-total {
  background: var(--bg-dark);
  border-radius: 14px;
  padding: 22px 26px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  flex-wrap: wrap;
}
.roi-total .k {
  font-family: var(--mono, ui-monospace, SFMono-Regular, Menlo, Consolas, monospace);
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--accent-soft);
}
.roi-total .v {
  font-size: 24px;
  font-weight: 700;
  color: #fff;
  letter-spacing: -0.01em;
  font-variant-numeric: tabular-nums;
  margin: 6px 0 4px;
}
.roi-total .s { font-size: 12.5px; color: #9fb0c4; }
.roi-foot {
  font-size: 12.5px;
  color: var(--muted);
  line-height: 1.55;
  margin: 16px 0 0;
  max-width: 900px;
}

/* ── Responsive ──────────────────────────────────────────────────────── */
@media (max-width: 820px) {
  h1 { font-size: 34px; }
  .hero { padding: 56px 0 48px; }
  .hero h1 { font-size: 36px; }
  .hero .subhead { font-size: 16px; }
  .pagehead { padding: 56px 0 24px; }
  .pagehead h1 { font-size: 30px; }
  section { padding: 48px 0; }
  .grid-3, .steps, .grid-2, .split-2 {
    grid-template-columns: 1fr;
  }
  .roi-calc { grid-template-columns: 1fr; }
  .pagehead h1 { font-size: 32px; }
  .ink-card { padding: 28px 24px; }
  footer.site .grid {
    grid-template-columns: 1fr;
    gap: 32px;
  }
  footer.site .legal-row {
    flex-direction: column;
    gap: 8px;
    align-items: flex-start;
  }
  nav.top ul.links { gap: 16px; flex-wrap: wrap; justify-content: flex-end; }
  nav.top ul.links a { font-size: 14px; }
}

@media (max-width: 520px) {
  .container { padding: 0 20px; }
  h1 { font-size: 28px; }
  .hero h1 { font-size: 30px; }
  nav.top ul.links { gap: 12px; }
  nav.top ul.links li:last-child a { padding: 7px 12px; }
  .roi-stats { grid-template-columns: 1fr; }
  .roi-total { padding: 20px; }
}