/* ============================================================
   ELECTRONIC REPAIRS UK - "Signal Restored"
   Design system: workshop black · valve-tube amber · scope green
   Mobile-first. OKLCH throughout.
   ============================================================ */

/* ---------- Fonts ---------- */
/* Anton (display / gig-poster) · Hanken Grotesk (body) · Spline Sans Mono (readouts) */

:root {
  /* Surfaces - warm workshop near-black */
  --bg:          oklch(0.145 0.006 60);
  --bg-2:        oklch(0.178 0.007 58);
  --surface:     oklch(0.205 0.009 56);
  --surface-2:   oklch(0.245 0.010 54);
  --line:        oklch(0.32 0.010 58);
  --line-strong: oklch(0.44 0.012 60);

  /* Ink */
  --ink:    oklch(0.95 0.010 85);
  --muted:  oklch(0.755 0.014 78);
  --faint:  oklch(0.60 0.012 72);

  /* Brand - valve-tube amber (primary) */
  --amber:        oklch(0.80 0.155 72);
  --amber-bright: oklch(0.87 0.145 82);
  --amber-hot:    oklch(0.66 0.185 46);
  --on-amber:     oklch(0.165 0.02 60);

  /* Accent - oscilloscope / VU signal green (seed 140°), used sparingly */
  --signal:      oklch(0.83 0.175 150);
  --signal-dim:  oklch(0.66 0.12 150);

  /* Glows */
  --glow-amber: 0 0 0 rgba(0,0,0,0);
  --tube-glow: radial-gradient(closest-side, oklch(0.72 0.19 55 / 0.55), oklch(0.6 0.2 40 / 0.15) 55%, transparent 78%);

  /* Type */
  --font-display: "Anton", "Arial Narrow", system-ui, sans-serif;
  --font-body: "Hanken Grotesk", system-ui, -apple-system, "Segoe UI", sans-serif;
  --font-mono: "Spline Sans Mono", ui-monospace, "SFMono-Regular", monospace;

  /* Fluid type scale (mobile-first, ratio ~1.28) */
  --fs-eyebrow: 0.8125rem;
  --fs-body:    1.0625rem;
  --fs-lead:    clamp(1.15rem, 1.03rem + 0.6vw, 1.4rem);
  --fs-h3:      clamp(1.4rem, 1.2rem + 1vw, 1.9rem);
  --fs-h2:      clamp(2.1rem, 1.55rem + 2.7vw, 3.6rem);
  --fs-h1:      clamp(2.9rem, 1.9rem + 5vw, 5.5rem);
  --fs-mega:    clamp(3.4rem, 1.7rem + 8.5vw, 7rem);

  /* Space */
  --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;
  --gutter: clamp(1.15rem, 0.6rem + 2.6vw, 2.5rem);
  --maxw: 1220px;
  --radius: 14px;
  --radius-sm: 9px;

  /* Motion */
  --ease-out: cubic-bezier(0.16, 1, 0.3, 1);       /* out-expo-ish */
  --ease-out-quart: cubic-bezier(0.25, 1, 0.5, 1);
  --dur: 0.6s;

  /* z-scale */
  --z-base: 1; --z-raise: 10; --z-nav: 100; --z-overlay: 900; --z-toast: 1000;

  color-scheme: dark;
}

/* ---------- Reset ---------- */
*, *::before, *::after { box-sizing: border-box; }
* { margin: 0; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; } }

body {
  font-family: var(--font-body);
  font-size: var(--fs-body);
  line-height: 1.62;
  color: var(--ink);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  overflow-x: hidden;
  font-feature-settings: "ss01", "cv01";
}

img, svg, canvas, video { display: block; max-width: 100%; }
img { height: auto; }
a { color: inherit; text-decoration: none; }
button { font: inherit; color: inherit; cursor: pointer; background: none; border: none; }
ul { list-style: none; padding: 0; }
::selection { background: var(--amber); color: var(--on-amber); }

:focus-visible {
  outline: 2px solid var(--signal);
  outline-offset: 3px;
  border-radius: 3px;
}

/* ---------- Typography ---------- */
h1, h2, h3, h4 { line-height: 1; font-weight: 400; text-wrap: balance; }
p { text-wrap: pretty; }

.display {
  font-family: var(--font-display);
  text-transform: uppercase;
  letter-spacing: 0.005em;
  line-height: 0.92;
  font-weight: 400;
}
.mono { font-family: var(--font-mono); }

.eyebrow {
  font-family: var(--font-mono);
  font-size: var(--fs-eyebrow);
  letter-spacing: 0.06em;
  color: var(--signal);
  display: inline-flex;
  align-items: center;
  gap: 0.6em;
  font-weight: 500;
}

.lead { font-size: var(--fs-lead); color: var(--muted); line-height: 1.5; max-width: 46ch; }

/* ---------- Layout ---------- */
.wrap { width: 100%; max-width: var(--maxw); margin-inline: auto; padding-inline: var(--gutter); }
.section { padding-block: clamp(3.5rem, 2rem + 7vw, 7rem); position: relative; }
.section--tight { padding-block: clamp(2.5rem, 1.5rem + 4vw, 4.5rem); }
.stack > * + * { margin-top: var(--sp-4); }

.bg-2 { background: var(--bg-2); }

/* Section head */
.sec-head { max-width: 60ch; }
.sec-head h2 { font-size: var(--fs-h2); margin-top: 0.5rem; }
.sec-head .lead { margin-top: 1rem; }

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 0.6em;
  font-family: var(--font-body); font-weight: 700; font-size: 1rem;
  padding: 0.95em 1.5em; border-radius: 100px;
  line-height: 1; white-space: nowrap;
  transition: transform 0.25s var(--ease-out), background 0.25s, box-shadow 0.35s, color 0.25s;
  will-change: transform;
}
.btn svg { width: 1.05em; height: 1.05em; }
.btn-primary {
  background: var(--amber); color: var(--on-amber);
  box-shadow: 0 0 0 rgba(0,0,0,0), 0 6px 20px oklch(0.66 0.185 46 / 0.25);
}
.btn-primary:hover {
  background: var(--amber-bright);
  box-shadow: 0 0 34px oklch(0.72 0.19 55 / 0.5), 0 10px 26px oklch(0.66 0.185 46 / 0.35);
  transform: translateY(-2px);
}
.btn-ghost {
  background: transparent; color: var(--ink);
  box-shadow: inset 0 0 0 1.5px var(--line-strong);
}
.btn-ghost:hover { box-shadow: inset 0 0 0 1.5px var(--amber); color: var(--amber-bright); transform: translateY(-2px); }
.btn-block { width: 100%; }

/* Pulsing signal dot */
.dot {
  width: 8px; height: 8px; border-radius: 50%;
  background: var(--signal); box-shadow: 0 0 10px var(--signal);
  display: inline-block; flex: none;
  animation: pulse 2s var(--ease-out) infinite;
}
@keyframes pulse { 0%,100% { opacity: 1; } 50% { opacity: 0.35; } }

/* ---------- Header ---------- */
.site-header {
  position: fixed; inset: 0 0 auto 0; z-index: var(--z-nav);
  padding-block: 0.85rem;
  transition: transform 0.45s var(--ease-out), background 0.4s, border-color 0.4s, backdrop-filter 0.4s;
  border-bottom: 1px solid transparent;
}
.site-header.scrolled {
  background: oklch(0.145 0.006 60 / 0.82);
  backdrop-filter: blur(14px) saturate(1.2);
  border-bottom-color: var(--line);
}
.site-header.hide { transform: translateY(-104%); }
.nav-inner { display: flex; align-items: center; justify-content: space-between; gap: 1rem; }

.brand { display: inline-flex; align-items: center; gap: 0.65rem; z-index: 2; }
.brand-mark { width: 30px; height: 30px; flex: none; }
.brand-name { line-height: 0.95; }
.brand-name b {
  font-family: var(--font-display); text-transform: uppercase;
  font-size: 1.02rem; letter-spacing: 0.02em; display: block; font-weight: 400;
}
.brand-name span {
  font-family: var(--font-mono); font-size: 0.62rem; letter-spacing: 0.22em;
  color: var(--amber); text-transform: uppercase;
}

.nav-links { display: none; }
.nav-actions { display: flex; align-items: center; gap: 0.75rem; }
.nav-phone { display: none; }

/* Hamburger */
.nav-toggle {
  width: 46px; height: 46px; display: inline-flex; align-items: center; justify-content: center;
  border-radius: 50%; box-shadow: inset 0 0 0 1.5px var(--line-strong); z-index: 2;
}
.nav-toggle span { position: relative; width: 20px; height: 2px; background: var(--ink); border-radius: 2px; transition: 0.3s var(--ease-out); }
.nav-toggle span::before, .nav-toggle span::after {
  content: ""; position: absolute; left: 0; width: 20px; height: 2px; background: var(--ink); border-radius: 2px; transition: 0.3s var(--ease-out);
}
.nav-toggle span::before { top: -6px; }
.nav-toggle span::after { top: 6px; }
body.menu-open .nav-toggle span { background: transparent; }
body.menu-open .nav-toggle span::before { top: 0; transform: rotate(45deg); }
body.menu-open .nav-toggle span::after { top: 0; transform: rotate(-45deg); }

/* Mobile menu overlay */
.mobile-menu {
  position: fixed; inset: 0; z-index: calc(var(--z-nav) - 5); /* below header so the X toggle stays tappable */
  background: oklch(0.125 0.006 60 / 0.97);
  backdrop-filter: blur(6px);
  display: flex; flex-direction: column; justify-content: center;
  padding: var(--gutter);
  opacity: 0; visibility: hidden; transform: translateY(-8px);
  transition: opacity 0.4s var(--ease-out), transform 0.5s var(--ease-out), visibility 0.4s;
}
body.menu-open .mobile-menu { opacity: 1; visibility: visible; transform: none; }
.mobile-menu a.m-link {
  font-family: var(--font-display); text-transform: uppercase;
  font-size: clamp(1.9rem, 1.2rem + 5vw, 3rem); letter-spacing: 0.01em;
  padding-block: 0.32em; color: var(--ink);
  display: flex; align-items: baseline; gap: 0.7rem;
  border-bottom: 1px solid var(--line);
  transition: color 0.25s, transform 0.35s var(--ease-out);
}
.mobile-menu a.m-link .idx { font-family: var(--font-mono); font-size: 0.8rem; color: var(--signal); letter-spacing: 0.1em; }
.mobile-menu a.m-link:hover, .mobile-menu a.m-link:focus-visible { color: var(--amber); transform: translateX(0.5rem); }
.mobile-menu .m-foot { margin-top: 2rem; display: flex; flex-direction: column; gap: 0.4rem; }
.mobile-menu .m-foot a { font-family: var(--font-mono); color: var(--muted); font-size: 0.95rem; }
.mobile-menu .m-foot a strong { color: var(--amber); }

/* current page link */
.nav-links a[aria-current="page"], .mobile-menu a[aria-current="page"] { color: var(--amber); }

/* ---------- Reveal (enhances an already-visible default) ---------- */
.js [data-reveal] { opacity: 0; transform: translateY(24px); transition: opacity 0.7s var(--ease-out), transform 0.8s var(--ease-out); }
.js [data-reveal].in { opacity: 1; transform: none; }
.js [data-reveal-stagger] > * { opacity: 0; transform: translateY(20px); transition: opacity 0.6s var(--ease-out), transform 0.7s var(--ease-out); }
.js [data-reveal-stagger].in > * { opacity: 1; transform: none; }

@media (prefers-reduced-motion: reduce) {
  .js [data-reveal], .js [data-reveal-stagger] > * { opacity: 1 !important; transform: none !important; transition: none !important; }
}

/* ---------- Footer ---------- */
.site-footer { background: oklch(0.12 0.006 60); border-top: 1px solid var(--line); padding-block: clamp(3rem, 2rem + 4vw, 4.5rem) 2rem; }
.foot-grid { display: grid; gap: 2.5rem; }
.foot-brand .brand { margin-bottom: 1rem; }
.foot-brand p { color: var(--muted); max-width: 34ch; font-size: 0.98rem; }
.foot-col h4 { font-family: var(--font-mono); font-size: 0.72rem; letter-spacing: 0.16em; text-transform: uppercase; color: var(--faint); margin-bottom: 1rem; font-weight: 500; }
.foot-col ul { display: flex; flex-direction: column; gap: 0.6rem; }
.foot-col a { color: var(--muted); transition: color 0.2s; display: inline-block; padding-block: 0.2rem; }
.foot-col a:hover { color: var(--amber); }
.foot-bottom { margin-top: 2.5rem; padding-top: 1.5rem; border-top: 1px solid var(--line); display: flex; flex-wrap: wrap; gap: 0.5rem 1.5rem; align-items: center; justify-content: space-between; font-size: 0.85rem; color: var(--faint); font-family: var(--font-mono); }
.foot-bottom a { color: var(--muted); }
.foot-bottom a:hover { color: var(--amber); }
.foot-bottom .credit a { color: var(--amber); }

/* ---------- Utility ---------- */
.amber { color: var(--amber); }
.signal { color: var(--signal); }
.center { text-align: center; }
.hidden-vis { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip: rect(0,0,0,0); white-space: nowrap; border: 0; }

/* Compact the header on small phones so the CTA doesn't crowd the hamburger */
@media (max-width: 559px) {
  .site-header { padding-block: 0.7rem; }
  .contact-cta { padding: 0.7em 1.05em; font-size: 0.88rem; }
  .nav-actions { gap: 0.55rem; }
  .nav-toggle { width: 44px; height: 44px; }
  .brand-mark { width: 27px; height: 27px; }
}

/* ============================================================
   Desktop / tablet refinements
   ============================================================ */
@media (min-width: 860px) {
  .nav-links { display: flex; align-items: center; gap: 1.6rem; }
  .nav-links a { font-size: 0.92rem; font-weight: 600; color: var(--muted); transition: color 0.2s; position: relative; padding-block: 0.3rem; }
  .nav-links a::after { content: ""; position: absolute; left: 0; bottom: 0; height: 2px; width: 100%; background: var(--amber); transform: scaleX(0); transform-origin: left; transition: transform 0.3s var(--ease-out); }
  .nav-links a:hover { color: var(--ink); }
  .nav-links a:hover::after, .nav-links a[aria-current="page"]::after { transform: scaleX(1); }
  .nav-toggle { display: none; }
  .nav-phone { display: inline-flex; align-items: center; gap: 0.5rem; font-family: var(--font-mono); font-weight: 600; font-size: 0.92rem; color: var(--ink); }
  .nav-phone svg { color: var(--amber); width: 1em; height: 1em; }
}