/* ==========================================================================
   Northline Roofing — Core Styles
   Fictional demonstration project.
   ========================================================================== */

:root {
  --color-background: #f7f6f2;
  --color-surface: #ffffff;
  --color-text: #111111;
  --color-text-soft: #5e5e59;
  --color-border: #c9c8c1;
  --color-accent: #e84d1c;
  --color-accent-hover: #c93c12;
  --color-dark: #171918;
  --color-light-on-dark: #f7f6f2;

  --font-heading: "Manrope", "Inter", -apple-system, sans-serif;
  --font-body: "Inter", "Manrope", -apple-system, sans-serif;

  --container-max: 1360px;
  --container-pad: 32px;
  --header-height: 84px;

  --ease: cubic-bezier(0.22, 0.61, 0.36, 1);
}

/* ---------- Reset ---------- */
*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  background: var(--color-background);
  color: var(--color-text);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}
img { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; }
ul, ol { list-style: none; margin: 0; padding: 0; }
button { font: inherit; color: inherit; background: none; border: none; cursor: pointer; }
input, textarea, select { font: inherit; color: inherit; }
h1, h2, h3, h4, p, dl, dd, figure, blockquote { margin: 0; }

.sr-only {
  position: absolute;
  width: 1px; height: 1px;
  padding: 0; margin: -1px;
  overflow: hidden;
  clip: rect(0,0,0,0);
  white-space: nowrap;
  border: 0;
}

.skip-link {
  position: absolute;
  top: -100px;
  left: 16px;
  background: var(--color-dark);
  color: var(--color-light-on-dark);
  padding: 12px 20px;
  z-index: 1000;
  transition: top 0.2s var(--ease);
}
.skip-link:focus { top: 16px; }

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

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

/* ---------- Typography ---------- */
h1, h2, h3 {
  font-family: var(--font-heading);
  font-weight: 800;
  letter-spacing: -0.02em;
  line-height: 1.05;
  color: var(--color-text);
}

h2 {
  font-size: clamp(2rem, 1.6rem + 1.8vw, 3.25rem);
}

h3 { font-size: 1.25rem; font-weight: 700; }

.section-lead {
  color: var(--color-text-soft);
  font-size: 1.05rem;
  max-width: 42ch;
  margin-top: 18px;
}

.rule-mark {
  display: block;
  width: 48px;
  height: 2px;
  background: var(--color-dark);
  margin: 20px 0;
}
.rule-mark--light { background: var(--color-light-on-dark); }

.text-link {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-weight: 600;
  border-bottom: 1px solid var(--color-text);
  padding-bottom: 4px;
  transition: color 0.2s var(--ease), border-color 0.2s var(--ease), gap 0.2s var(--ease);
}
.text-link:hover { color: var(--color-accent); border-color: var(--color-accent); gap: 12px; }

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 15px 26px;
  font-weight: 600;
  font-size: 0.95rem;
  border: 1px solid transparent;
  transition: background-color 0.2s var(--ease), color 0.2s var(--ease), border-color 0.2s var(--ease), transform 0.15s var(--ease);
  white-space: nowrap;
}
.btn:hover { transform: translateY(-1px); }
.btn span { transition: transform 0.2s var(--ease); }
.btn:hover span { transform: translateX(3px); }

.btn-primary {
  background: var(--color-accent);
  color: #fff;
  border-color: var(--color-accent);
}
.btn-primary:hover { background: var(--color-accent-hover); border-color: var(--color-accent-hover); }

.btn-outline {
  background: transparent;
  color: var(--color-text);
  border-color: var(--color-dark);
}
.btn-outline:hover { background: var(--color-dark); color: var(--color-light-on-dark); }

.btn-outline-sm {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 18px;
  font-size: 0.85rem;
  font-weight: 600;
  border: 1px solid var(--color-dark);
  transition: background-color 0.2s var(--ease), color 0.2s var(--ease);
}
.btn-outline-sm:hover { background: var(--color-dark); color: var(--color-light-on-dark); }

/* ==========================================================================
   Header
   ========================================================================== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 500;
  background: rgba(247, 246, 242, 0.92);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--color-border);
  transition: box-shadow 0.25s var(--ease);
}
.site-header.is-scrolled { box-shadow: 0 6px 20px rgba(0,0,0,0.06); }

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: var(--header-height);
  gap: 24px;
}

.wordmark {
  font-family: var(--font-heading);
  font-weight: 800;
  font-size: 1.05rem;
  letter-spacing: 0.01em;
  white-space: nowrap;
}
.wordmark-strong { color: var(--color-text); }
.wordmark-light { color: var(--color-text-soft); font-weight: 600; margin-left: 6px; }

.main-nav ul { display: flex; gap: 32px; }
.main-nav a {
  font-size: 0.92rem;
  font-weight: 500;
  color: var(--color-text);
  position: relative;
  padding: 4px 0;
}
.main-nav a::after {
  content: "";
  position: absolute;
  left: 0; bottom: -2px;
  width: 0; height: 1px;
  background: var(--color-accent);
  transition: width 0.2s var(--ease);
}
.main-nav a:hover::after { width: 100%; }

.header-actions { display: flex; align-items: center; gap: 18px; }
.header-phone { font-size: 0.9rem; font-weight: 600; white-space: nowrap; }
.header-cta { padding: 10px 20px; font-size: 0.85rem; }

.menu-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  width: 42px; height: 42px;
  border: 1px solid var(--color-border);
}
.menu-toggle-bars { display: flex; flex-direction: column; gap: 5px; width: 20px; }
.menu-toggle-bars span {
  display: block;
  height: 2px;
  width: 100%;
  background: var(--color-text);
  transition: transform 0.25s var(--ease), opacity 0.25s var(--ease);
}
.menu-toggle[aria-expanded="true"] .menu-toggle-bars span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.menu-toggle[aria-expanded="true"] .menu-toggle-bars span:nth-child(2) { opacity: 0; }
.menu-toggle[aria-expanded="true"] .menu-toggle-bars span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

.mobile-nav {
  position: fixed;
  inset: var(--header-height) 0 0 0;
  background: var(--color-background);
  z-index: 400;
  flex-direction: column;
  justify-content: space-between;
  padding: 32px var(--container-pad) 40px;
  overflow-y: auto;
}
.mobile-nav[hidden] { display: none; }
.mobile-nav:not([hidden]) { display: flex; }
.mobile-nav ul { display: flex; flex-direction: column; gap: 4px; }
.mobile-nav a {
  display: block;
  padding: 16px 4px;
  font-family: var(--font-heading);
  font-size: 1.6rem;
  font-weight: 700;
  border-bottom: 1px solid var(--color-border);
}
.mobile-nav-footer {
  display: flex;
  flex-direction: column;
  gap: 16px;
  padding-top: 24px;
}
.mobile-nav-footer .btn { justify-content: center; }

/* ==========================================================================
   Hero
   ========================================================================== */
.hero { padding-top: 56px; }

.hero-grid {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 40px;
  align-items: end;
  padding-bottom: 40px;
}

.hero-heading {
  font-size: clamp(2.6rem, 1.8rem + 4.2vw, 5.6rem);
  letter-spacing: -0.03em;
}

.hero-sub {
  max-width: 46ch;
  margin-top: 22px;
  font-size: 1.1rem;
  color: var(--color-text-soft);
}

.hero-actions { margin-top: 32px; }

.trust-line {
  margin-top: 18px;
  font-size: 0.85rem;
  color: var(--color-text-soft);
  font-weight: 500;
}

.hero-editorial {
  text-align: right;
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  color: var(--color-text-soft);
  line-height: 1.7;
}
.hero-editorial .rule-mark { margin-left: auto; }

.hero-image {
  position: relative;
  width: 100%;
  height: clamp(280px, 30vw, 460px);
  overflow: hidden;
  border-top: 1px solid var(--color-border);
}
.hero-image img { width: 100%; height: 100%; object-fit: cover; object-position: center 55%; }
.hero-image-caption {
  position: absolute;
  right: 32px;
  bottom: 32px;
  color: #fff;
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.05em;
  line-height: 1.7;
  text-align: right;
  text-shadow: 0 1px 6px rgba(0,0,0,0.5);
}

/* ==========================================================================
   Built to Last
   ========================================================================== */
.built-to-last { padding: 96px 0; }

.built-grid {
  display: grid;
  grid-template-columns: 0.8fr 0.72fr 0.82fr;
  gap: 32px;
  align-items: stretch;
}

.stat-row {
  display: flex;
  margin-top: 44px;
  border-top: 1px solid var(--color-border);
  padding-top: 28px;
}
.stat { padding-right: 28px; margin-right: 28px; border-right: 1px solid var(--color-border); }
.stat:last-child { border-right: none; margin-right: 0; padding-right: 0; }
.stat-number {
  font-family: var(--font-heading);
  font-weight: 800;
  font-size: 2rem;
  letter-spacing: -0.02em;
}
.stat-label {
  margin-top: 6px;
  font-size: 0.78rem;
  color: var(--color-text-soft);
  line-height: 1.4;
}

.built-media-stack {
  display: flex;
  flex-direction: column;
  gap: 20px;
  height: 100%;
}
.built-media-stack .media-item { flex: 1; display: flex; flex-direction: column; }
.built-media-stack .media-item img { flex: 1; aspect-ratio: 5/4; }

.media-item--tall { display: flex; flex-direction: column; height: 100%; }
.media-item--tall img { flex: 1; aspect-ratio: auto; }

.media-item img { width: 100%; height: 100%; object-fit: cover; border: 1px solid var(--color-border); }
.media-item figcaption {
  margin-top: 12px;
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--color-text-soft);
}

/* ==========================================================================
   Services
   ========================================================================== */
.services { padding: 88px 0; border-top: 1px solid var(--color-border); }

.services-grid {
  display: grid;
  grid-template-columns: 0.85fr 1.35fr;
  gap: 48px;
  align-items: stretch;
}

.service-list { margin-top: 44px; border-top: 1px solid var(--color-border); }

.service-row { border-bottom: 1px solid var(--color-border); }

.service-toggle {
  width: 100%;
  display: grid;
  grid-template-columns: 48px 1fr 28px;
  align-items: center;
  padding: 22px 0;
  text-align: left;
  transition: color 0.2s var(--ease);
}
.service-toggle:hover { color: var(--color-accent); }

.service-index {
  font-family: var(--font-heading);
  font-weight: 700;
  color: var(--color-text-soft);
  font-size: 0.9rem;
}
.service-name {
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: 1.2rem;
}
.service-arrow {
  transition: transform 0.25s var(--ease);
  font-size: 1.1rem;
  justify-self: end;
}
.service-toggle[aria-expanded="true"] .service-arrow { transform: rotate(90deg); color: var(--color-accent); }

.service-panel { overflow: hidden; }
.service-panel p {
  padding: 0 0 22px 48px;
  color: var(--color-text-soft);
  max-width: 52ch;
}

.services-image { position: relative; height: 100%; }
.services-image img { width: 100%; height: 100%; min-height: 430px; max-height: 560px; aspect-ratio: 4/3; object-fit: cover; border: 1px solid var(--color-border); }
.services-image figcaption {
  position: absolute;
  top: 20px; right: 20px;
  color: #fff;
  font-size: 0.72rem;
  font-weight: 600;
  letter-spacing: 0.05em;
  text-shadow: 0 1px 6px rgba(0,0,0,0.5);
}

/* ==========================================================================
   Projects
   ========================================================================== */
.projects { padding: 88px 0; border-top: 1px solid var(--color-border); }

.section-heading-row {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  margin-bottom: 44px;
  gap: 20px;
}

.project-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}
.project-card-img { overflow: hidden; border: 1px solid var(--color-border); }
.project-card-img img {
  width: 100%;
  aspect-ratio: 5/4;
  object-fit: cover;
  transition: transform 0.5s var(--ease);
}
.project-card:hover .project-card-img img { transform: scale(1.06); }

.project-card figcaption {
  display: flex;
  flex-direction: column;
  gap: 2px;
  margin-top: 14px;
}
.project-category { font-weight: 700; font-size: 0.95rem; }
.project-location { font-size: 0.82rem; color: var(--color-text-soft); }

/* ==========================================================================
   Process
   ========================================================================== */
.process {
  padding-block: clamp(64px, 7vw, 88px);
  border-top: 1px solid var(--color-border);
  overflow: hidden;
}

.process-grid {
  display: grid;
  grid-template-columns:
    minmax(250px, 0.8fr)
    minmax(360px, 1fr)
    minmax(390px, 1.05fr);
  grid-template-areas: "intro gallery steps";
  gap: clamp(32px, 4vw, 56px);
  align-items: start;
  width: 100%;
}

.process-copy {
  grid-area: intro;
  min-width: 0;
}

.process-media {
  grid-area: gallery;
  display: grid;
  grid-template-rows: repeat(2, minmax(0, 1fr));
  gap: 12px;
  width: 100%;
  height: 420px;
  min-width: 0;
  overflow: hidden;
}

.process-image {
  width: 100%;
  height: 100%;
  min-width: 0;
  overflow: hidden;
  border: 1px solid var(--color-border);
}

.process-image img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.process-image:first-child img { object-position: center 35%; }
.process-image:last-child img { object-position: center 58%; }

.process-steps {
  grid-area: steps;
  min-width: 0;
  display: block;
  visibility: visible;
  opacity: 1;
  position: static;
  border-top: 1px solid var(--color-border);
}
.process-steps li {
  display: flex;
  gap: 20px;
  padding: 26px 0;
  border-bottom: 1px solid var(--color-border);
}
.step-index {
  font-family: var(--font-heading);
  font-weight: 800;
  font-size: 1.1rem;
  color: var(--color-accent);
  flex-shrink: 0;
}
.process-steps h3 { margin-bottom: 6px; }
.process-steps p { color: var(--color-text-soft); font-size: 0.95rem; }

/* ==========================================================================
   Why Us
   ========================================================================== */
.why-us {
  padding: 60px 0;
  background: var(--color-dark);
  color: var(--color-light-on-dark);
}
.why-list {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
}
.why-list li {
  padding: 0 24px;
  border-left: 1px solid rgba(247,246,242,0.2);
  display: flex;
  flex-direction: column;
  gap: 14px;
}
.why-list li:first-child { padding-left: 0; }
.why-index {
  font-family: var(--font-heading);
  font-weight: 700;
  color: var(--color-accent);
  font-size: 0.9rem;
}
.why-title {
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: 1.1rem;
  letter-spacing: -0.01em;
}

/* ==========================================================================
   Testimonial
   ========================================================================== */
.testimonial { padding: 88px 0; background: var(--color-surface); }

.testimonial-grid {
  display: grid;
  grid-template-columns: 1.2fr 0.8fr auto;
  gap: 48px;
  align-items: center;
}

.stars { color: var(--color-accent); font-size: 1.2rem; letter-spacing: 3px; }

.testimonial-copy blockquote {
  margin-top: 18px;
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: clamp(1.4rem, 1.1rem + 1.2vw, 2rem);
  letter-spacing: -0.01em;
  line-height: 1.25;
}
.testimonial-attribution { margin-top: 20px; font-weight: 700; }
.testimonial-disclaimer { margin-top: 8px; font-size: 0.78rem; color: var(--color-text-soft); }

.testimonial-image img {
  width: 100%;
  height: 100%;
  min-height: 320px;
  max-height: 420px;
  aspect-ratio: 5/4;
  object-fit: cover;
  border: 1px solid var(--color-border);
}

.testimonial-editorial {
  text-align: right;
  font-size: 0.78rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  color: var(--color-text-soft);
  line-height: 1.7;
  white-space: nowrap;
}
.testimonial-editorial .rule-mark { margin-left: auto; }

/* ==========================================================================
   FAQ
   ========================================================================== */
.faq { padding: 88px 0; border-top: 1px solid var(--color-border); }
.faq-container { max-width: 880px; margin: 0 auto; }
.faq h2 { text-align: center; }
.faq .rule-mark { margin-left: auto; margin-right: auto; }

.accordion { margin-top: 40px; border-top: 1px solid var(--color-border); }
.accordion-item { border-bottom: 1px solid var(--color-border); }
.accordion-item h3 { font-size: 1rem; }

.accordion-trigger {
  width: 100%;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 20px;
  padding: 24px 4px;
  text-align: left;
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: 1.05rem;
  transition: color 0.2s var(--ease);
}
.accordion-trigger:hover { color: var(--color-accent); }
.accordion-trigger::after {
  content: "+";
  font-size: 1.4rem;
  font-weight: 400;
  flex-shrink: 0;
  transition: transform 0.25s var(--ease);
  color: var(--color-accent);
}
.accordion-trigger[aria-expanded="true"]::after { transform: rotate(45deg); }

.accordion-panel { overflow: hidden; }
.accordion-panel p {
  padding: 0 4px 24px;
  max-width: 62ch;
  color: var(--color-text-soft);
}

/* ==========================================================================
   Final CTA
   ========================================================================== */
.final-cta { background: #f1f0ec; color: var(--color-text); padding: 96px 0; }

.final-cta-grid {
  display: grid;
  grid-template-columns: 0.9fr 1.1fr;
  gap: 48px;
  align-items: center;
}

.final-cta-copy h2 {
  color: var(--color-text);
  font-size: clamp(2.2rem, 1.7rem + 2.2vw, 3.6rem);
}
.final-cta-copy .rule-mark { background: var(--color-dark); }
.final-cta-copy p {
  margin-top: 18px;
  color: var(--color-text-soft);
  max-width: 40ch;
}
.final-cta-copy .btn-primary { margin-top: 32px; }

.final-cta-image { position: relative; height: 100%; }
.final-cta-image img {
  width: 100%;
  height: 100%;
  min-height: 320px;
  max-height: 440px;
  aspect-ratio: 16/10;
  object-fit: cover;
  border: 1px solid var(--color-border);
}
.final-cta-image figcaption {
  position: absolute;
  top: 20px; right: 20px;
  text-align: right;
  font-size: 0.72rem;
  font-weight: 600;
  letter-spacing: 0.05em;
  color: #fff;
  text-shadow: 0 1px 6px rgba(0,0,0,0.5);
}

/* ==========================================================================
   Contact Form
   ========================================================================== */
.contact { padding: 88px 0; }
.contact-container { max-width: 760px; margin: 0 auto; }
.contact-intro { text-align: center; }
.contact-intro .rule-mark { margin-left: auto; margin-right: auto; }
.contact-intro .section-lead { margin-left: auto; margin-right: auto; text-align: center; max-width: 50ch; }

.estimate-form { margin-top: 48px; }

.form-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
}

.form-field { margin-bottom: 24px; }
.form-field label,
.fieldset-label {
  display: block;
  font-size: 0.85rem;
  font-weight: 600;
  margin-bottom: 8px;
}

.form-field input[type="text"],
.form-field input[type="tel"],
.form-field input[type="email"],
.form-field select,
.form-field textarea {
  width: 100%;
  padding: 14px 16px;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  transition: border-color 0.2s var(--ease);
}
.form-field input:focus,
.form-field select:focus,
.form-field textarea:focus {
  border-color: var(--color-dark);
}
.form-field textarea { resize: vertical; min-height: 110px; }

.form-field select {
  appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='8'%3E%3Cpath d='M1 1l5 5 5-5' stroke='%23111' stroke-width='1.5' fill='none'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 16px center;
}

.radio-group { display: flex; gap: 20px; padding-top: 6px; }
.radio-option { display: flex; align-items: center; gap: 8px; font-size: 0.92rem; font-weight: 500; }
.radio-option input { accent-color: var(--color-accent); width: 16px; height: 16px; }

.field-error {
  margin-top: 6px;
  font-size: 0.8rem;
  color: var(--color-accent);
  min-height: 1em;
}

.form-field.has-error input,
.form-field.has-error select,
.form-field.has-error textarea {
  border-color: var(--color-accent);
}

.form-submit { width: 100%; justify-content: center; margin-top: 8px; }

.privacy-note {
  margin-top: 18px;
  font-size: 0.8rem;
  color: var(--color-text-soft);
  text-align: center;
}

.form-success {
  margin-top: 24px;
  padding: 20px 22px;
  background: var(--color-dark);
  color: var(--color-light-on-dark);
}

/* ==========================================================================
   Footer
   ========================================================================== */
.site-footer {
  background: var(--color-dark);
  color: var(--color-light-on-dark);
  padding: 90px 0 0;
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.4fr 0.8fr 0.8fr 0.8fr;
  gap: 40px;
  padding-bottom: 60px;
  border-bottom: 1px solid rgba(247,246,242,0.15);
}

.footer-brand .wordmark--footer { font-size: 1.15rem; }
.footer-brand .wordmark-strong { color: var(--color-light-on-dark); }
.footer-brand .wordmark-light { color: rgba(247,246,242,0.6); }
.footer-tagline { margin: 14px 0 18px; color: rgba(247,246,242,0.7); }
.footer-brand p { margin-top: 6px; font-size: 0.92rem; }
.footer-brand a:hover { color: var(--color-accent); }
.footer-area { color: rgba(247,246,242,0.6); }

.footer-col-title {
  display: block;
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  color: rgba(247,246,242,0.5);
  margin-bottom: 18px;
}
.footer-nav ul, .social-list { display: flex; flex-direction: column; gap: 12px; }
.footer-nav a, .social-list a { font-size: 0.92rem; color: rgba(247,246,242,0.85); }
.footer-nav a:hover, .social-list a:hover { color: var(--color-accent); }

.footer-bottom {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 20px;
  padding: 28px 0;
  font-size: 0.78rem;
  color: rgba(247,246,242,0.5);
}
.footer-closing { font-weight: 700; letter-spacing: 0.03em; color: rgba(247,246,242,0.75); }

/* ==========================================================================
   Back to top
   ========================================================================== */
.back-to-top {
  position: fixed;
  right: 24px;
  bottom: 24px;
  width: 48px; height: 48px;
  background: var(--color-dark);
  color: var(--color-light-on-dark);
  align-items: center;
  justify-content: center;
  font-size: 1.1rem;
  z-index: 300;
  opacity: 0;
  transform: translateY(10px);
  pointer-events: none;
  transition: opacity 0.25s var(--ease), transform 0.25s var(--ease), background-color 0.2s var(--ease);
}
.back-to-top[hidden] { display: none; }
.back-to-top:not([hidden]) { display: flex; }
.back-to-top.is-visible { opacity: 1; transform: translateY(0); pointer-events: auto; }
.back-to-top:hover { background: var(--color-accent); }

/* ==========================================================================
   Scroll reveal
   ========================================================================== */
.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); }

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .reveal { opacity: 1; transform: none; transition: none; }
  .btn, .btn span, .project-card-img img, .service-arrow, .accordion-trigger::after {
    transition: none !important;
  }
}