/* =========================================================================
   CUBIX CORE — Design System
   Direction: modular / structural — the brand is built from a single unit
   (the cube) repeated and rotated, so the UI borrows a blueprint / grid
   vocabulary: hairline rule grids, isometric cube marks, coordinate-style
   eyebrows instead of generic 01/02/03 numbering.
   ========================================================================= */

:root {
  /* ---- Color tokens ---- */
  /* Palette pulled directly from the Cubix Core cube mark: two structural
     orange faces, a deep red-orange shadow face, on true black and white. */
  --ink: #121212;           /* primary dark surface — near-black */
  --ink-soft: #1c1c1c;      /* secondary dark surface */
  --paper: #ffffff;         /* primary light surface — true white */
  --paper-soft: #f2f2f0;    /* secondary light surface */
  --cobalt: #f2600c;        /* primary accent — logo's structural orange */
  --cobalt-dim: #7a3305;    /* muted burnt-orange for dark-on-dark */
  --amber: #f7a928;         /* secondary accent — logo's amber face, CTA / highlight */
  --slate: #a3a3a3;         /* muted text on dark */
  --slate-dark: #595959;    /* muted text on light */
  --line: rgba(255, 255, 255, 0.1);
  --line-dark: rgba(0, 0, 0, 0.12);
  --white: #ffffff;
  --rust: #c42a1b;          /* deep red-orange — logo's shadow face, used sparingly */

  /* ---- Type tokens ---- */
  --font-display: "Space Grotesk", "Arial Narrow", sans-serif;
  --font-body: "Inter", -apple-system, BlinkMacSystemFont, sans-serif;
  --font-mono: "JetBrains Mono", "Courier New", monospace;

  /* ---- Layout tokens ---- */
  --max-width: 1240px;
  --gutter: clamp(1.25rem, 4vw, 3rem);
  --radius: 4px;
  --ease: cubic-bezier(0.16, 1, 0.3, 1);
}

/* ---------------------------------------------------------------------- */
/* Reset & base                                                           */
/* ---------------------------------------------------------------------- */
*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; }
@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; }
}

body {
  margin: 0;
  background: var(--ink);
  color: var(--paper);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

img { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; }
ul { list-style: none; margin: 0; padding: 0; }
button { font-family: inherit; cursor: pointer; }
input, textarea, select { font-family: inherit; }

h1, h2, h3, h4 {
  font-family: var(--font-display);
  font-weight: 600;
  line-height: 1.08;
  margin: 0 0 0.5em;
  letter-spacing: -0.01em;
}
h1 { font-size: clamp(2.4rem, 6vw, 4.6rem); }
h2 { font-size: clamp(1.9rem, 4vw, 3rem); }
h3 { font-size: clamp(1.2rem, 2vw, 1.6rem); }
p { margin: 0 0 1em; color: var(--slate); }

.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--gutter);
}

.eyebrow {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--cobalt);
  display: inline-flex;
  align-items: center;
  gap: 0.6em;
  margin-bottom: 1.1em;
}
.eyebrow::before {
  content: "";
  width: 7px;
  height: 7px;
  background: var(--cobalt);
  transform: rotate(45deg);
  flex: none;
}

.section { padding: clamp(4rem, 9vw, 7.5rem) 0; position: relative; }
.section--soft { background: var(--ink-soft); }
.section--light { background: var(--paper); color: var(--ink); }
.section--light p { color: var(--slate-dark); }
.section--light h1, .section--light h2, .section--light h3 { color: var(--ink); }

.grid-lines {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(var(--line) 1px, transparent 1px),
    linear-gradient(90deg, var(--line) 1px, transparent 1px);
  background-size: 64px 64px;
  pointer-events: none;
  mask-image: linear-gradient(to bottom, black, transparent);
}
.section--light .grid-lines {
  background-image:
    linear-gradient(var(--line-dark) 1px, transparent 1px),
    linear-gradient(90deg, var(--line-dark) 1px, transparent 1px);
}

/* ---------------------------------------------------------------------- */
/* Buttons                                                                */
/* ---------------------------------------------------------------------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.6em;
  padding: 0.95em 1.7em;
  font-family: var(--font-mono);
  font-size: 0.82rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  border: 1px solid transparent;
  border-radius: var(--radius);
  transition: all 0.25s var(--ease);
  white-space: nowrap;
}
.btn--primary {
  background: var(--amber);
  color: var(--ink);
  font-weight: 600;
}
.btn--primary:hover { background: #ffc659; transform: translateY(-2px); }
.btn--ghost {
  border-color: var(--line);
  color: var(--paper);
}
.btn--ghost:hover { border-color: var(--cobalt); color: var(--cobalt); }
.section--light .btn--ghost { border-color: var(--line-dark); color: var(--ink); }
.section--light .btn--ghost:hover { border-color: var(--cobalt); color: var(--cobalt); }
.btn svg { width: 14px; height: 14px; transition: transform 0.25s var(--ease); }
.btn:hover svg { transform: translateX(3px); }

/* ---------------------------------------------------------------------- */
/* Navbar                                                                 */
/* ---------------------------------------------------------------------- */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 500;
  background: rgba(14, 17, 22, 0.72);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border-bottom: 1px solid var(--line);
  transition: background 0.3s var(--ease);
}
.navbar__inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0.9rem var(--gutter);
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.navbar__logo { display: flex; align-items: center; gap: 0.6rem; }
.navbar__logo img {
  height: 34px;
  width: 34px;
  object-fit: contain;
  border-radius: 6px;
  background: var(--paper);
  padding: 3px;
}
.navbar__logo span {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.1rem;
  letter-spacing: -0.01em;
}
.navbar__links {
  display: flex;
  align-items: center;
  gap: 2.1rem;
}
.navbar__links a {
  font-size: 0.88rem;
  font-weight: 500;
  color: var(--slate);
  position: relative;
  padding: 0.3rem 0;
  transition: color 0.2s var(--ease);
}
.navbar__links a:hover, .navbar__links a.active { color: var(--white); }
.navbar__links a.active::after {
  content: "";
  position: absolute;
  bottom: -2px;
  left: 0;
  right: 0;
  height: 2px;
  background: var(--cobalt);
}
.navbar__cta { display: flex; align-items: center; gap: 1rem; }
.navbar__toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  padding: 6px;
}
.navbar__toggle span { width: 22px; height: 2px; background: var(--white); transition: 0.25s; }

@media (max-width: 900px) {
  .navbar__links {
    position: fixed;
    top: 63px;
    left: 0;
    right: 0;
    background: var(--ink-soft);
    flex-direction: column;
    align-items: flex-start;
    padding: 1.5rem var(--gutter) 2rem;
    gap: 1.1rem;
    border-bottom: 1px solid var(--line);
    transform: translateY(-130%);
    opacity: 0;
    transition: all 0.3s var(--ease);
  }
  .navbar__links.is-open { transform: translateY(0); opacity: 1; }
  .navbar__toggle { display: flex; }
  .navbar__cta .btn--ghost { display: none; }
}

/* ---------------------------------------------------------------------- */
/* Hero + Cube signature animation                                       */
/* ---------------------------------------------------------------------- */
.hero {
  position: relative;
  padding-top: clamp(8rem, 16vw, 11rem);
  padding-bottom: clamp(4rem, 8vw, 6rem);
  overflow: hidden;
}
.hero__inner {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 3rem;
  align-items: center;
}
@media (max-width: 960px) {
  .hero__inner { grid-template-columns: 1fr; }
}
.hero__copy p.lead { font-size: 1.1rem; max-width: 46ch; }
.hero__actions { display: flex; gap: 1rem; margin-top: 2rem; flex-wrap: wrap; }
.hero__stats {
  display: flex;
  gap: clamp(1.5rem, 4vw, 3rem);
  margin-top: 3.5rem;
  padding-top: 2rem;
  border-top: 1px solid var(--line);
}
.hero__stats div strong {
  display: block;
  font-family: var(--font-display);
  font-size: 1.8rem;
  color: var(--white);
}
.hero__stats div span {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: var(--slate);
  letter-spacing: 0.05em;
  text-transform: uppercase;
}

/* Isometric cube stack — the signature element */
.cube-stack {
  position: relative;
  width: 100%;
  aspect-ratio: 1 / 1;
  display: flex;
  align-items: center;
  justify-content: center;
  perspective: 1200px;
}
.cube-scene {
  position: relative;
  width: 220px;
  height: 220px;
  transform-style: preserve-3d;
  animation: rotateScene 22s linear infinite;
}
@keyframes rotateScene {
  from { transform: rotateX(-18deg) rotateY(0deg); }
  to { transform: rotateX(-18deg) rotateY(360deg); }
}
.cube {
  position: absolute;
  width: 90px;
  height: 90px;
  transform-style: preserve-3d;
  animation: floatCube 4.5s ease-in-out infinite;
  opacity: 0;
  animation: floatCube 4.5s ease-in-out infinite, assemble 1s var(--ease) forwards;
}
.cube__face {
  position: absolute;
  width: 90px;
  height: 90px;
  border: 1px solid rgba(242, 96, 12, 0.55);
  background: linear-gradient(135deg, rgba(242,96,12,0.28), rgba(196,42,27,0.08));
}
.cube__face--top    { transform: rotateX(90deg) translateZ(45px); background: linear-gradient(135deg, rgba(247,169,40,0.4), rgba(247,169,40,0.08)); border-color: rgba(247,169,40,0.65); }
.cube__face--front   { transform: translateZ(45px); }
.cube__face--right  { transform: rotateY(90deg) translateZ(45px); }
.cube--a { transform: translate3d(-70px,-40px,40px); animation-delay: 0.1s, 0s; }
.cube--b { transform: translate3d(60px,-60px,-20px); animation-delay: 0.35s, .15s; }
.cube--c { transform: translate3d(0px,50px,10px); animation-delay: 0.55s, .3s; }
.cube--d { transform: translate3d(-40px,30px,-60px); animation-delay: 0.75s, .45s; }
@keyframes floatCube {
  0%, 100% { margin-top: 0; }
  50% { margin-top: -10px; }
}
@keyframes assemble {
  from { opacity: 0; filter: blur(6px); }
  to { opacity: 1; filter: blur(0); }
}
@media (prefers-reduced-motion: reduce) {
  .cube-scene { animation: none; transform: rotateX(-18deg) rotateY(-24deg); }
  .cube { animation: none; opacity: 1; }
}
@media (max-width: 960px) { .cube-stack { max-width: 320px; margin: 0 auto; } }

/* ---------------------------------------------------------------------- */
/* Logo strip                                                            */
/* ---------------------------------------------------------------------- */
.logo-strip { padding: 2.5rem 0; border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }
.logo-strip__row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 2rem;
  opacity: 0.6;
}
.logo-strip__row span {
  font-family: var(--font-mono);
  font-size: 1.05rem;
  letter-spacing: 0.03em;
  color: var(--slate);
}

/* ---------------------------------------------------------------------- */
/* Cards: services / portfolio / team / testimonials                     */
/* ---------------------------------------------------------------------- */
.section__head {
  display: flex;
  justify-content: space-between;
  align-items: flex-end;
  gap: 2rem;
  margin-bottom: 3rem;
  flex-wrap: wrap;
}
.section__head p { max-width: 42ch; margin: 0; }

.grid {
  display: grid;
  gap: 1.5rem;
}
.grid--3 { grid-template-columns: repeat(3, 1fr); }
.grid--4 { grid-template-columns: repeat(4, 1fr); }
.grid--2 { grid-template-columns: repeat(2, 1fr); }
@media (max-width: 960px) { .grid--3, .grid--4 { grid-template-columns: repeat(2, 1fr); } }
@media (max-width: 640px) { .grid--3, .grid--4, .grid--2 { grid-template-columns: 1fr; } }

.card {
  background: var(--ink-soft);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 2rem;
  transition: transform 0.3s var(--ease), border-color 0.3s var(--ease);
  position: relative;
}
.card:hover { transform: translateY(-6px); border-color: var(--cobalt); }
.section--light .card { background: var(--white); border-color: var(--line-dark); }

.card__icon {
  width: 46px;
  height: 46px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(242, 96, 12, 0.12);
  border-radius: var(--radius);
  color: var(--cobalt);
  margin-bottom: 1.4rem;
}
.card__icon svg { width: 22px; height: 22px; }
.card h3 { margin-bottom: 0.6rem; }
.card ul { margin-top: 1rem; display: flex; flex-direction: column; gap: 0.5rem; }
.card ul li {
  font-size: 0.86rem;
  color: var(--slate);
  display: flex;
  gap: 0.6em;
  align-items: flex-start;
}
.section--light .card ul li { color: var(--slate-dark); }
.card ul li::before { content: "→"; color: var(--cobalt); flex: none; }

.card__coord {
  position: absolute;
  top: 1.4rem;
  right: 1.4rem;
  font-family: var(--font-mono);
  font-size: 0.68rem;
  color: var(--slate);
  opacity: 0.7;
}

/* Portfolio */
.portfolio-item {
  position: relative;
  overflow: hidden;
  border-radius: var(--radius);
  border: 1px solid var(--line);
  background: var(--ink-soft);
}
.portfolio-item__img { aspect-ratio: 4/3; overflow: hidden; }
.portfolio-item__img img { width: 100%; height: 100%; object-fit: cover; transition: transform 0.5s var(--ease); }
.portfolio-item:hover .portfolio-item__img img { transform: scale(1.08); }
.portfolio-item__body { padding: 1.4rem; }
.portfolio-item__tag {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--amber);
  margin-bottom: 0.5rem;
  display: inline-block;
}
.portfolio-item__body h3 { font-size: 1.15rem; margin-bottom: 0.4rem; }
.portfolio-item__body p { font-size: 0.9rem; margin: 0; }
.portfolio-filters { display: flex; gap: 0.8rem; flex-wrap: wrap; margin-bottom: 2.5rem; }
.filter-btn {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  padding: 0.55em 1.1em;
  border: 1px solid var(--line);
  border-radius: 999px;
  color: var(--slate);
  background: transparent;
  transition: 0.2s var(--ease);
}
.filter-btn:hover, .filter-btn.active { color: var(--ink); background: var(--amber); border-color: var(--amber); }

/* Team */
.team-card { text-align: left; }
.team-card__img { aspect-ratio: 1/1; border-radius: var(--radius); overflow: hidden; margin-bottom: 1.1rem; border: 1px solid var(--line); }
.team-card__img img { width: 100%; height: 100%; object-fit: cover; filter: grayscale(40%); transition: filter 0.3s var(--ease); }
.team-card:hover .team-card__img img { filter: grayscale(0%); }
.team-card h3 { margin-bottom: 0.15rem; font-size: 1.05rem; }
.team-card span { font-family: var(--font-mono); font-size: 0.75rem; color: var(--cobalt); text-transform: uppercase; letter-spacing: 0.04em; }

/* Testimonials */
.testimonial-slider { position: relative; max-width: 760px; margin: 0 auto; text-align: center; }
.testimonial-slide { display: none; }
.testimonial-slide.active { display: block; animation: fadeUp 0.5s var(--ease); }
@keyframes fadeUp { from { opacity: 0; transform: translateY(12px); } to { opacity: 1; transform: translateY(0); } }
.testimonial-slide blockquote {
  font-family: var(--font-display);
  font-size: clamp(1.2rem, 2.4vw, 1.6rem);
  font-weight: 500;
  color: var(--white);
  margin: 0 0 1.6rem;
  line-height: 1.4;
}
.section--light .testimonial-slide blockquote { color: var(--ink); }
.testimonial-slide__author { font-family: var(--font-mono); font-size: 0.8rem; color: var(--slate); }
.testimonial-slide__author strong { color: var(--cobalt); }
.testimonial-dots { display: flex; justify-content: center; gap: 0.6rem; margin-top: 2rem; }
.testimonial-dots button { width: 8px; height: 8px; border-radius: 50%; background: var(--line); border: none; padding: 0; }
.testimonial-dots button.active { background: var(--cobalt); width: 22px; border-radius: 4px; transition: 0.3s var(--ease); }

/* Newsletter */
.newsletter {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: clamp(2rem, 5vw, 3.5rem);
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 2rem;
  flex-wrap: wrap;
  background: linear-gradient(135deg, rgba(242,96,12,0.1), transparent);
}
.newsletter form { display: flex; gap: 0.8rem; flex-wrap: wrap; }
.newsletter input[type="email"] {
  background: transparent;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 0.9em 1.1em;
  color: var(--white);
  min-width: 260px;
  font-size: 0.9rem;
}
.newsletter input::placeholder { color: var(--slate); }

/* ---------------------------------------------------------------------- */
/* Page header (inner pages)                                             */
/* ---------------------------------------------------------------------- */
.page-header {
  padding-top: clamp(7rem, 14vw, 9.5rem);
  padding-bottom: 3rem;
  position: relative;
}
.page-header .breadcrumb {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--slate);
  letter-spacing: 0.05em;
  text-transform: uppercase;
  margin-bottom: 1rem;
}
.page-header .breadcrumb span { color: var(--cobalt); }

/* About page specifics */
.mv-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 1.5rem; }
@media (max-width: 720px) { .mv-grid { grid-template-columns: 1fr; } }
.mv-card {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 2.2rem;
  background: var(--ink-soft);
}
.why-list { display: grid; grid-template-columns: repeat(2, 1fr); gap: 1.2rem 2rem; margin-top: 2.5rem; }
@media (max-width: 720px) { .why-list { grid-template-columns: 1fr; } }
.why-item { display: flex; gap: 1rem; align-items: flex-start; }
.why-item__num { font-family: var(--font-mono); color: var(--amber); font-size: 0.85rem; flex: none; padding-top: 0.2em; }
.why-item h4 { font-family: var(--font-display); font-size: 1.02rem; margin: 0 0 0.3rem; color: var(--white); }
.why-item p { margin: 0; font-size: 0.9rem; }

/* ---------------------------------------------------------------------- */
/* Contact page                                                          */
/* ---------------------------------------------------------------------- */
.contact-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 3rem; align-items: start; }
@media (max-width: 900px) { .contact-grid { grid-template-columns: 1fr; } }
.form-group { margin-bottom: 1.3rem; }
.form-group label {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--slate);
  margin-bottom: 0.5em;
}
.form-group input, .form-group textarea {
  width: 100%;
  background: var(--ink-soft);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 0.9em 1em;
  color: var(--white);
  font-size: 0.95rem;
  transition: border-color 0.2s var(--ease);
}
.form-group input:focus, .form-group textarea:focus {
  outline: none;
  border-color: var(--cobalt);
}
.form-group textarea { resize: vertical; min-height: 140px; }
#formStatus { margin-top: 1rem; font-size: 0.88rem; font-family: var(--font-mono); display: none; padding: 0.9em 1em; border-radius: var(--radius); }
#formStatus.success { display: block; background: rgba(242,96,12,0.12); color: #ffab6b; border: 1px solid var(--cobalt); }
#formStatus.error { display: block; background: rgba(255,80,80,0.1); color: #ff8080; border: 1px solid #ff5050; }

.contact-info-item { display: flex; gap: 1rem; padding: 1.3rem 0; border-bottom: 1px solid var(--line); }
.contact-info-item__icon { color: var(--cobalt); flex: none; }
.contact-info-item h4 { font-family: var(--font-display); font-size: 0.98rem; margin: 0 0 0.2rem; color: var(--white); }
.contact-info-item p { margin: 0; font-size: 0.9rem; }
.map-embed { border-radius: var(--radius); overflow: hidden; border: 1px solid var(--line); margin-top: 1.5rem; }
.map-embed iframe { width: 100%; height: 260px; border: 0; display: block; filter: grayscale(60%) invert(90%) contrast(90%); }
.social-row { display: flex; gap: 0.8rem; margin-top: 1.5rem; }
.social-row a {
  width: 38px; height: 38px;
  display: flex; align-items: center; justify-content: center;
  border: 1px solid var(--line); border-radius: var(--radius);
  transition: 0.2s var(--ease);
}
.social-row a:hover { border-color: var(--cobalt); color: var(--cobalt); }
.social-row svg { width: 16px; height: 16px; }

/* ---------------------------------------------------------------------- */
/* Footer                                                                 */
/* ---------------------------------------------------------------------- */
.footer { background: var(--ink); border-top: 1px solid var(--line); padding-top: 4rem; }
.footer__top { display: grid; grid-template-columns: 1.4fr 1fr 1fr 1.2fr; gap: 2.5rem; padding-bottom: 3rem; }
@media (max-width: 900px) { .footer__top { grid-template-columns: 1fr 1fr; } }
@media (max-width: 560px) { .footer__top { grid-template-columns: 1fr; } }
.footer__brand { display: flex; align-items: center; gap: 0.6rem; margin-bottom: 1rem; }
.footer__brand img { height: 32px; width: 32px; object-fit: contain; border-radius: 6px; background: var(--paper); padding: 3px; }
.footer__brand span { font-family: var(--font-display); font-weight: 700; font-size: 1.05rem; }
.footer p.desc { font-size: 0.88rem; max-width: 32ch; }
.footer h4 {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--white);
  margin-bottom: 1.1rem;
}
.footer ul li { margin-bottom: 0.7rem; }
.footer ul li a { font-size: 0.9rem; color: var(--slate); transition: color 0.2s var(--ease); }
.footer ul li a:hover { color: var(--cobalt); }
.footer__bottom {
  border-top: 1px solid var(--line);
  padding: 1.5rem 0;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 1rem;
  font-size: 0.8rem;
  color: var(--slate);
}
.footer__bottom .social-row a { width: 34px; height: 34px; }

/* Back to top */
.back-to-top {
  position: fixed;
  bottom: 1.8rem;
  right: 1.8rem;
  width: 46px;
  height: 46px;
  border-radius: 50%;
  background: var(--cobalt);
  color: var(--white);
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  visibility: hidden;
  transform: translateY(10px);
  transition: all 0.3s var(--ease);
  z-index: 400;
  border: none;
}
.back-to-top.is-visible { opacity: 1; visibility: visible; transform: translateY(0); }
.back-to-top:hover { background: var(--amber); color: var(--ink); }
.back-to-top svg { width: 18px; height: 18px; }

/* Reveal-on-scroll */
.reveal { opacity: 0; transform: translateY(24px); transition: opacity 0.7s var(--ease), transform 0.7s var(--ease); }
.reveal.is-visible { opacity: 1; transform: translateY(0); }

/* Skip link (a11y) */
.skip-link {
  position: absolute; left: -999px; top: auto;
  background: var(--cobalt); color: white; padding: 0.8em 1.2em; z-index: 999;
}
.skip-link:focus { left: 1rem; top: 1rem; }

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