/* =============================================================================
   52 North Advisory — stylesheet
   -----------------------------------------------------------------------------
   Structure:
     1. Design tokens (:root)          ← EDIT COLOURS / SPACING / TYPE HERE
     2. Reset & base
     3. Layout primitives
     4. Typography & motif
     5. Header & navigation
     6. Hero
     7. Services
     8. Sector focus
     9. Approach (dark band)
    10. Perspective
    11. About
    12. Contact (accent band)
    13. Footer
    14. Utilities, focus, motion
   ========================================================================== */

/* 1. DESIGN TOKENS ---------------------------------------------------------- */
:root {
  /* Palette — adjust the whole site from here */
  --ink:        #14171a;   /* near-black: primary text, dark bands            */
  --ink-2:      #1c2024;   /* slightly lifted dark, for layering              */
  --paper:      #f7f5f0;   /* warm off-white: primary background              */
  --paper-2:    #efece3;   /* subtle warm tint: alternating sections          */
  --slate:      #4e555c;   /* secondary text (AA on paper)                    */
  --slate-2:    #626871;   /* tertiary / meta text (AA on paper)              */
  --line:       #d9d4c8;   /* hairlines on paper                              */
  --line-dark:  #2c3238;   /* hairlines on dark                               */
  --accent:     #0e4e57;   /* deep teal — links, marks, accent band           */
  --accent-hov: #0a3c44;   /* accent hover (darker)                           */
  --accent-lt:  #7fb8c1;   /* light teal — accent text on dark backgrounds    */
  --on-dark:    #f3f1ea;   /* text on dark bands                              */
  --on-dark-2:  #a7adb3;   /* secondary text on dark bands                    */

  /* Typography */
  --font-sans: ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto,
               "Helvetica Neue", Arial, sans-serif;
  --font-mono: ui-monospace, "SF Mono", "Cascadia Code", "Segoe UI Mono",
               Consolas, "Liberation Mono", monospace;

  /* Fluid type scale (clamp: min, preferred, max) */
  --fs-meta:  clamp(0.72rem, 0.68rem + 0.2vw, 0.8rem);
  --fs-small: clamp(0.85rem, 0.82rem + 0.2vw, 0.94rem);
  --fs-body:  clamp(1rem, 0.96rem + 0.25vw, 1.12rem);
  --fs-lead:  clamp(1.15rem, 1.05rem + 0.6vw, 1.4rem);
  --fs-h4:    clamp(1.1rem, 1.02rem + 0.4vw, 1.3rem);
  --fs-h3:    clamp(1.35rem, 1.2rem + 0.8vw, 1.85rem);
  --fs-h2:    clamp(1.7rem, 1.4rem + 1.5vw, 2.6rem);
  --fs-h1:    clamp(2.1rem, 1.55rem + 2.9vw, 4rem);

  /* Spacing scale */
  --sp-1: 0.5rem;
  --sp-2: 0.75rem;
  --sp-3: 1rem;
  --sp-4: 1.5rem;
  --sp-5: 2rem;
  --sp-6: 3rem;
  --sp-7: 4.5rem;
  --sp-8: 6.5rem;

  /* Layout */
  --measure: 62ch;                 /* readable line length              */
  --container: 74rem;              /* max content width                 */
  --container-narrow: 52rem;
  --gutter: clamp(1.15rem, 5vw, 3rem);
  --section-y: clamp(3.5rem, 8vw, 7rem);
  --radius: 3px;                   /* restrained, near-square           */
  --header-h: 4.5rem;

  /* Motion */
  --ease: cubic-bezier(0.2, 0.6, 0.2, 1);
  --dur: 0.5s;
}

/* 2. RESET & BASE ----------------------------------------------------------- */
*, *::before, *::after { box-sizing: border-box; }

* { margin: 0; }

html {
  -webkit-text-size-adjust: 100%;
  text-size-adjust: 100%;
  scroll-behavior: smooth;
  /* offset anchor targets for the sticky header */
  scroll-padding-top: calc(var(--header-h) + 1rem);
}

body {
  font-family: var(--font-sans);
  font-size: var(--fs-body);
  line-height: 1.65;
  color: var(--ink);
  background: var(--paper);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
}

img, svg { display: block; max-width: 100%; height: auto; }

a { color: var(--accent); text-decoration-thickness: 1px; text-underline-offset: 3px; }
a:hover { color: var(--accent-hov); }

h1, h2, h3, h4 { line-height: 1.12; font-weight: 620; letter-spacing: -0.015em; text-wrap: balance; }
p { text-wrap: pretty; }

::selection { background: var(--accent); color: var(--paper); }

/* 3. LAYOUT PRIMITIVES ------------------------------------------------------ */
.container {
  width: 100%;
  max-width: var(--container);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.section { padding-block: var(--section-y); }
.section--tight { padding-block: clamp(2.75rem, 6vw, 5rem); }

.section-head { margin-bottom: clamp(2rem, 4vw, 3.25rem); }
.section-head h2 { font-size: var(--fs-h2); max-width: 20ch; }
.section-head .lead { margin-top: var(--sp-3); max-width: var(--measure); color: var(--slate); font-size: var(--fs-lead); }

/* skip link */
.skip-link {
  position: absolute; left: var(--sp-3); top: -100%;
  background: var(--ink); color: var(--on-dark);
  padding: 0.6rem 1rem; border-radius: var(--radius); z-index: 200;
  transition: top 0.2s var(--ease);
}
.skip-link:focus { top: var(--sp-3); color: var(--on-dark); }

/* 4. TYPOGRAPHY & MOTIF ----------------------------------------------------- */

/* coordinate / section marker — the recurring 52°N motif */
.coord {
  font-family: var(--font-mono);
  font-size: var(--fs-meta);
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--accent);
  display: inline-flex;
  align-items: center;
  gap: 0.6em;
}
.coord::before {
  content: "";
  width: 1.75rem; height: 1px;
  background: currentColor;
  opacity: 0.6;
  flex: none;
}
.coord--on-dark { color: var(--accent-lt); }

/* section index eyebrow, e.g. "01 · Services" */
.eyebrow {
  font-family: var(--font-mono);
  font-size: var(--fs-meta);
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--slate-2);
  margin-bottom: var(--sp-3);
  display: block;
}
.eyebrow b { color: var(--accent); font-weight: 600; }
.eyebrow--on-dark { color: var(--on-dark-2); }
.eyebrow--on-dark b { color: var(--accent-lt); }

/* button */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.55em;
  font: inherit;
  font-size: var(--fs-small);
  font-weight: 600;
  line-height: 1;
  padding: 0.85rem 1.35rem;
  min-height: 44px;
  border: 1px solid var(--ink);
  border-radius: var(--radius);
  background: var(--ink);
  color: var(--on-dark);
  text-decoration: none;
  cursor: pointer;
  transition: background var(--dur) var(--ease), color var(--dur) var(--ease),
              border-color var(--dur) var(--ease), transform 0.15s var(--ease);
}
.btn:hover { background: var(--accent); border-color: var(--accent); color: var(--on-dark); }
.btn:active { transform: translateY(1px); }
.btn .arrow { transition: transform 0.25s var(--ease); }
.btn:hover .arrow { transform: translateX(3px); }

.btn--ghost { background: transparent; color: var(--ink); }
.btn--ghost:hover { background: var(--ink); color: var(--on-dark); border-color: var(--ink); }

.btn--on-accent { background: var(--paper); border-color: var(--paper); color: var(--accent); }
.btn--on-accent:hover { background: transparent; color: var(--paper); border-color: var(--paper); }

/* 5. HEADER & NAVIGATION ---------------------------------------------------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: transparent;
  transition: background var(--dur) var(--ease), border-color var(--dur) var(--ease),
              box-shadow var(--dur) var(--ease);
  border-bottom: 1px solid transparent;
}
.site-header.is-scrolled {
  background: color-mix(in srgb, var(--paper) 88%, transparent);
  -webkit-backdrop-filter: blur(8px);
  backdrop-filter: blur(8px);
  border-bottom-color: var(--line);
}
.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--sp-4);
  min-height: var(--header-h);
}

/* wordmark */
.wordmark {
  display: inline-flex;
  align-items: center;
  gap: 0.65rem;
  text-decoration: none;
  color: var(--ink);
  line-height: 1;
}
.wordmark:hover { color: var(--ink); }
.wordmark__mark { flex: none; }
.wordmark__text { display: flex; flex-direction: column; gap: 0.1rem; }
.wordmark__name {
  font-weight: 680;
  font-size: 1.02rem;
  letter-spacing: 0.02em;
}
.wordmark__sub {
  font-family: var(--font-mono);
  font-size: 0.62rem;
  letter-spacing: 0.34em;
  color: var(--slate-2);
  text-transform: uppercase;
}

/* desktop nav */
.primary-nav { display: flex; align-items: center; gap: clamp(1rem, 2.5vw, 2rem); }
.nav-list {
  display: flex;
  align-items: center;
  gap: clamp(1rem, 2.5vw, 2rem);
  list-style: none;
  padding: 0;
}
.nav-list a {
  color: var(--ink);
  text-decoration: none;
  font-size: var(--fs-small);
  font-weight: 500;
  padding: 0.5rem 0;
  position: relative;
}
.nav-list a::after {
  content: "";
  position: absolute; left: 0; bottom: 0;
  width: 0; height: 1.5px;
  background: var(--accent);
  transition: width 0.25s var(--ease);
}
.nav-list a:hover { color: var(--accent); }
.nav-list a:hover::after, .nav-list a:focus-visible::after { width: 100%; }

/* mobile toggle */
.nav-toggle {
  display: none;
  width: 44px; height: 44px;
  align-items: center; justify-content: center;
  background: transparent;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  cursor: pointer;
  color: var(--ink);
}
.nav-toggle .bars, .nav-toggle .bars::before, .nav-toggle .bars::after {
  content: "";
  display: block;
  width: 20px; height: 1.5px;
  background: currentColor;
  transition: transform 0.3s var(--ease), opacity 0.2s var(--ease);
}
.nav-toggle .bars { position: relative; }
.nav-toggle .bars::before { position: absolute; top: -6px; }
.nav-toggle .bars::after { position: absolute; top: 6px; }
.nav-toggle[aria-expanded="true"] .bars { background: transparent; }
.nav-toggle[aria-expanded="true"] .bars::before { transform: translateY(6px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] .bars::after  { transform: translateY(-6px) rotate(-45deg); }

/* 6. HERO ------------------------------------------------------------------- */
.hero {
  position: relative;
  padding-block: clamp(3.5rem, 10vw, 8rem) clamp(3rem, 8vw, 6rem);
  overflow: hidden;
}
.hero__inner { position: relative; z-index: 2; max-width: 54rem; }
.hero__eyebrow {
  font-family: var(--font-mono);
  font-size: var(--fs-meta);
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--slate-2);
  margin-bottom: var(--sp-4);
}
.hero__eyebrow b { color: var(--accent); font-weight: 600; }
.hero h1 {
  font-size: var(--fs-h1);
  max-width: 18ch;
  margin-bottom: var(--sp-4);
}
.hero__sub {
  font-size: var(--fs-lead);
  color: var(--slate);
  max-width: 46ch;
  margin-bottom: var(--sp-5);
}
.hero__cta { display: flex; flex-wrap: wrap; align-items: center; gap: var(--sp-4); }
.hero__cta-note { font-size: var(--fs-small); color: var(--slate-2); }

/* latitude motif — decorative, purely visual */
.hero__motif {
  position: absolute;
  inset: 0;
  z-index: 1;
  pointer-events: none;
  color: var(--accent);
}
.hero__motif svg { position: absolute; right: -6%; top: 50%; transform: translateY(-50%);
  width: min(46rem, 64%); height: auto; opacity: 0.22; }
.hero__coord-label { font-family: var(--font-mono); font-size: 13px; fill: currentColor;
  letter-spacing: 0.08em; }
.hero__pulse { transform-box: fill-box; transform-origin: center;
  animation: heroPulse 4.8s var(--ease) infinite; }
@keyframes heroPulse {
  0%   { opacity: 0.45; transform: scale(0.7); }
  70%  { opacity: 0;    transform: scale(1.6); }
  100% { opacity: 0;    transform: scale(1.6); }
}

/* 7. SERVICES --------------------------------------------------------------- */
.services-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 0;
  border-top: 1px solid var(--line);
}
.service {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--sp-2);
  padding-block: clamp(1.5rem, 3vw, 2.25rem);
  border-bottom: 1px solid var(--line);
}
.service__idx {
  font-family: var(--font-mono);
  font-size: var(--fs-meta);
  color: var(--accent);
  letter-spacing: 0.1em;
  display: inline-flex;
  align-items: center;
  gap: 0.7rem;
}
.service__mark { width: 30px; height: 30px; flex: none; color: var(--accent); }
.service h3 { font-size: var(--fs-h4); }
.service p { color: var(--slate); max-width: var(--measure); }

/* 8. SECTOR FOCUS ----------------------------------------------------------- */
.sector { background: var(--paper-2); }
.sector__statement {
  font-size: var(--fs-h3);
  font-weight: 500;
  letter-spacing: -0.01em;
  max-width: 26ch;
  line-height: 1.3;
}
.sector__statement em { font-style: normal; color: var(--accent); }
.sector__body { color: var(--slate); max-width: var(--measure); margin-top: var(--sp-4); }

/* 9. APPROACH (dark band) --------------------------------------------------- */
.approach {
  background: var(--ink);
  color: var(--on-dark);
  position: relative;
  overflow: hidden;
}
.approach > .container { position: relative; z-index: 1; }
.approach__motif { position: absolute; inset: 0; z-index: 0; pointer-events: none;
  color: var(--accent-lt); }
.approach__motif svg { position: absolute; right: -6%; top: 50%; transform: translateY(-50%);
  width: min(30rem, 56%); height: auto; opacity: 0.6; }
.approach .section-head h2 { color: var(--on-dark); }
.approach .section-head .lead { color: var(--on-dark-2); }
.principles {
  display: grid;
  grid-template-columns: 1fr;
  gap: 0;
  border-top: 1px solid var(--line-dark);
}
.principle {
  padding-block: clamp(1.5rem, 3vw, 2.25rem);
  border-bottom: 1px solid var(--line-dark);
  display: grid;
  gap: var(--sp-2);
}
.principle__head { display: flex; align-items: baseline; gap: 0.9rem; }
.principle__no {
  font-family: var(--font-mono);
  font-size: var(--fs-meta);
  color: var(--accent-lt);
  letter-spacing: 0.1em;
}
.principle h3 { font-size: var(--fs-h4); color: var(--on-dark); }
.principle p { color: var(--on-dark-2); max-width: var(--measure); }

/* 10. PERSPECTIVE ----------------------------------------------------------- */
.perspective__inner { max-width: var(--container-narrow); }
.perspective blockquote {
  font-size: var(--fs-h3);
  font-weight: 500;
  line-height: 1.35;
  letter-spacing: -0.01em;
  margin-top: var(--sp-4);
}
.perspective blockquote p + p { margin-top: var(--sp-4); }

/* 11. ABOUT ----------------------------------------------------------------- */
.about { background: var(--paper-2); }
.about__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(1.5rem, 4vw, 3rem);
}
.about__body p { max-width: var(--measure); color: var(--slate); }
.about__body p + p { margin-top: var(--sp-4); }
.about__body strong { color: var(--ink); font-weight: 620; }
/* aside reserved so a portrait can be added later without a redesign */
.about__aside { align-self: start; }
.about__card {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: var(--sp-5);
  background: var(--paper);
}
.about__card .coord { margin-bottom: var(--sp-3); }
.about__card dt { font-family: var(--font-mono); font-size: var(--fs-meta);
  letter-spacing: 0.1em; text-transform: uppercase; color: var(--slate-2); }
.about__card dd { margin: 0 0 var(--sp-3); font-weight: 500; }
.about__card dd:last-child { margin-bottom: 0; }

/* 12. CONTACT (accent band) ------------------------------------------------- */
.contact { background: var(--accent); color: var(--on-dark); position: relative; overflow: hidden; }
.contact > .container { position: relative; z-index: 1; }
.contact__motif { position: absolute; inset: 0; z-index: 0; pointer-events: none; color: var(--paper); }
.contact__motif svg { position: absolute; right: -3%; bottom: -12%;
  width: min(30rem, 54%); height: auto; opacity: 0.12; }
.contact .eyebrow { color: color-mix(in srgb, var(--paper) 70%, transparent); }
.contact .eyebrow b { color: var(--paper); }
.contact h2 { font-size: var(--fs-h2); color: var(--paper); max-width: 16ch; }
.contact__lead { color: color-mix(in srgb, var(--paper) 82%, transparent);
  font-size: var(--fs-lead); max-width: var(--measure); margin-top: var(--sp-3); }
.contact__details {
  display: flex; flex-wrap: wrap; gap: clamp(1.25rem, 4vw, 3rem);
  margin-top: var(--sp-6);
  list-style: none; padding: 0;
}
.contact__details li { display: grid; gap: 0.25rem; }
.contact__details .label {
  font-family: var(--font-mono); font-size: var(--fs-meta);
  letter-spacing: 0.12em; text-transform: uppercase;
  color: color-mix(in srgb, var(--paper) 62%, transparent);
}
.contact__details a, .contact__details .value { color: var(--paper); font-weight: 500;
  font-size: var(--fs-lead); text-decoration: none; }
.contact__details a { text-decoration: underline; text-underline-offset: 4px;
  text-decoration-color: color-mix(in srgb, var(--paper) 45%, transparent); }
.contact__details a:hover { color: var(--paper); text-decoration-color: var(--paper); }
.contact__cta { margin-top: var(--sp-6); }
/* LinkedIn stays hidden until a real URL is set (see index.html + JS) */
[data-linkedin][hidden] { display: none; }

/* 13. FOOTER ---------------------------------------------------------------- */
.site-footer { background: var(--ink); color: var(--on-dark-2); padding-block: var(--sp-7) var(--sp-5); }
.footer-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--sp-6);
}
.footer-brand .wordmark { color: var(--on-dark); }
.footer-brand .wordmark__name { color: var(--on-dark); }
.footer-brand p { margin-top: var(--sp-3); font-size: var(--fs-small); max-width: 34ch; }
.footer-cols { display: grid; grid-template-columns: 1fr 1fr; gap: var(--sp-5); }
.footer-col h3 {
  font-family: var(--font-mono); font-size: var(--fs-meta);
  letter-spacing: 0.14em; text-transform: uppercase;
  color: var(--on-dark-2); font-weight: 500; margin-bottom: var(--sp-3);
  line-height: 1.4; letter-spacing: 0.14em;
}
.footer-col ul { list-style: none; padding: 0; display: grid; gap: 0.55rem; }
.footer-col a { color: var(--on-dark); text-decoration: none; font-size: var(--fs-small); }
.footer-col a:hover { color: var(--accent-lt); }
.footer-col .value { font-size: var(--fs-small); color: var(--on-dark); }
.footer-col .value--muted { color: var(--on-dark-2); }
.footer-bottom {
  margin-top: var(--sp-6);
  padding-top: var(--sp-4);
  border-top: 1px solid var(--line-dark);
  display: flex; flex-wrap: wrap; gap: var(--sp-3);
  justify-content: space-between; align-items: center;
  font-size: var(--fs-meta); color: var(--on-dark-2);
}
.footer-bottom .coord { color: var(--on-dark-2); }
.footer-bottom .coord::before { background: var(--on-dark-2); }

/* PROSE / LEGAL PAGES ------------------------------------------------------- */
.container--prose { max-width: var(--container-narrow); }
.legal-page { padding-top: calc(var(--header-h) + clamp(2rem, 5vw, 3.5rem)); }
.legal-page h1 { font-size: var(--fs-h1); margin-block: var(--sp-3) var(--sp-4); }
.legal-page .lead { font-size: var(--fs-lead); color: var(--slate); max-width: var(--measure);
  margin-bottom: var(--sp-6); }
.legal-page h2 { font-size: var(--fs-h4); margin-top: var(--sp-6); margin-bottom: var(--sp-2); }
.legal-page p { max-width: var(--measure); color: var(--slate); }
.legal-page p + p { margin-top: var(--sp-3); }
.legal-page a { color: var(--accent); }
.legal-note { margin-top: var(--sp-6); padding: var(--sp-4);
  border-left: 2px solid var(--accent); background: var(--paper-2);
  font-size: var(--fs-small); border-radius: 0 var(--radius) var(--radius) 0; }

.legal-dl { display: grid; grid-template-columns: 1fr; gap: 0;
  margin-block: var(--sp-4) var(--sp-6); border-top: 1px solid var(--line); }
.legal-dl dt { font-family: var(--font-mono); font-size: var(--fs-meta);
  letter-spacing: 0.1em; text-transform: uppercase; color: var(--slate-2);
  padding-top: var(--sp-3); }
.legal-dl dd { margin: 0; padding-bottom: var(--sp-3); border-bottom: 1px solid var(--line);
  font-weight: 500; color: var(--ink); }
@media (min-width: 600px) {
  .legal-dl { grid-template-columns: 16rem 1fr; }
  .legal-dl dt { border-bottom: 1px solid var(--line); padding-bottom: var(--sp-3); }
}
.footer-bottom--single { margin-top: 0; border-top: none; padding-top: 0; }
.footer-bottom--single a { color: var(--on-dark); text-decoration: none; }
.footer-bottom--single a:hover { color: var(--accent-lt); }

/* 404 ----------------------------------------------------------------------- */
.error-page { display: grid; place-items: center; min-height: 100dvh;
  padding-block: var(--sp-7); text-align: left; }
.error-page__inner { max-width: 44rem; }
.error-page__code { font-family: var(--font-mono); font-size: clamp(3rem, 12vw, 5rem);
  font-weight: 500; color: var(--accent); line-height: 1; margin-block: var(--sp-3) var(--sp-2); }
.error-page h1 { font-size: var(--fs-h1); margin-bottom: var(--sp-3); }
.error-page__msg { font-size: var(--fs-lead); color: var(--slate); max-width: var(--measure); }
.error-page__actions { display: flex; flex-wrap: wrap; gap: var(--sp-3); margin-top: var(--sp-5); }

/* 14. UTILITIES, FOCUS, MOTION ---------------------------------------------- */
.visually-hidden {
  position: absolute !important; width: 1px; height: 1px;
  padding: 0; margin: -1px; overflow: hidden; clip: rect(0 0 0 0);
  white-space: nowrap; border: 0;
}

/* visible, consistent focus for keyboard users */
:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 3px;
  border-radius: 2px;
}
.approach :focus-visible, .contact :focus-visible, .site-footer :focus-visible {
  outline-color: var(--accent-lt);
}

/* scroll-reveal: only active when JS present; no-JS shows everything */
.reveal { opacity: 1; }
.js .reveal {
  opacity: 0;
  transform: translateY(14px);
  transition: opacity 0.6s var(--ease), transform 0.6s var(--ease);
  will-change: opacity, transform;
}
.js .reveal.is-visible { opacity: 1; transform: none; }

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
  }
  .js .reveal { opacity: 1; transform: none; }
}

/* =============================================================================
   RESPONSIVE — mobile-first; the rules above target small screens.
   Breakpoints layer capability on as space allows.
   ========================================================================== */

/* ≥600px — two-up service/principle grids, footer columns breathe */
@media (min-width: 600px) {
  .service { grid-template-columns: auto 1fr; gap: var(--sp-4); align-items: start; }
  .principle { grid-template-columns: 4rem 1fr; gap: var(--sp-4); align-items: baseline; }
  .principle__head { grid-column: 1 / -1; }
}

/* ≥768px — tablet: multi-column grids, nav becomes horizontal */
@media (min-width: 768px) {
  .services-grid { grid-template-columns: 1fr 1fr; column-gap: clamp(2rem, 5vw, 4rem); }
  .services-grid { border-top: none; }
  .service { border-top: 1px solid var(--line); border-bottom: none; }
  .service { grid-template-columns: 1fr; gap: var(--sp-2); }

  .principles { grid-template-columns: 1fr 1fr; column-gap: clamp(2rem, 5vw, 4rem);
    border-top: none; }
  .principle { border-top: 1px solid var(--line-dark); border-bottom: none;
    grid-template-columns: 1fr; }
  .principle__head { grid-column: auto; }

  .sector { }
  .sector__inner { display: grid; grid-template-columns: 1.1fr 1fr;
    gap: clamp(2rem, 5vw, 4rem); align-items: center; }
  .sector__body { margin-top: 0; }

  .about__grid { grid-template-columns: 1.6fr 1fr; align-items: start; }

  .footer-grid { grid-template-columns: 1.4fr 1fr; gap: clamp(3rem, 8vw, 6rem); }
}

/* ≥1024px — desktop refinements */
@media (min-width: 1024px) {
  .services-grid { column-gap: 5rem; }
  .principles { column-gap: 5rem; }
}

/* -----------------------------------------------------------------------------
   MOBILE NAVIGATION (< 768px). The panel is a slide-down sheet.
   Base (mobile) shows the toggle and hides the desktop list until opened.
   --------------------------------------------------------------------------- */
@media (max-width: 767.98px) {
  .nav-toggle { display: inline-flex; }

  .primary-nav {
    position: fixed;
    inset: var(--header-h) 0 auto 0;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    background: var(--paper);
    border-bottom: 1px solid var(--line);
    box-shadow: 0 24px 40px -28px rgba(0,0,0,0.4);
    padding: var(--sp-3) var(--gutter) var(--sp-5);
    transform: translateY(-8px);
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.25s var(--ease), transform 0.25s var(--ease),
                visibility 0s linear 0.25s;
    max-height: calc(100dvh - var(--header-h));
    overflow-y: auto;
  }
  .primary-nav.is-open {
    transform: translateY(0);
    opacity: 1;
    visibility: visible;
    transition: opacity 0.25s var(--ease), transform 0.25s var(--ease), visibility 0s;
  }
  .nav-list { flex-direction: column; align-items: stretch; gap: 0; width: 100%; }
  .nav-list li { border-bottom: 1px solid var(--line); }
  .nav-list a {
    display: flex; align-items: center;
    min-height: 52px;                /* generous touch target */
    font-size: 1.05rem;
    padding: 0.5rem 0;
  }
  .nav-list a::after { display: none; }
  .primary-nav .btn { margin-top: var(--sp-4); width: 100%; justify-content: center; }

  /* header gets a solid backing whenever the menu is open */
  .site-header.nav-open {
    background: var(--paper);
    border-bottom-color: var(--line);
  }
}

/* prevent body scroll while the mobile menu is open (class set by JS) */
body.nav-locked { overflow: hidden; }