/* ==========================================================================
   Gas Details — styles.css
   Mobile-first. 8px spacing scale. 12px card radius / 8px button radius.
   ========================================================================== */

:root {
  --green-deep: #12281E;
  --green: #1B4332;
  --green-mid: #2D6A4F;
  --green-glow: #40916C;
  --pearl: #F4F3EF;
  --pearl-warm: #EAE8E1;
  --black: #0B0C0B;
  --black-soft: #16181A;
  --text-muted: #8A8F8B;        /* for use on dark backgrounds — passes AA there */
  --text-muted-on-light: #5C6258; /* darker variant for use on pearl backgrounds — passes AA */

  --radius-card: 12px;
  --radius-btn: 8px;

  --space-1: 8px;
  --space-2: 16px;
  --space-3: 24px;
  --space-4: 32px;
  --space-5: 40px;
  --space-6: 48px;
  --space-7: 64px;
  --space-8: 80px;
  --space-9: 96px;

  --font-body: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;

  --ease-out: cubic-bezier(0.16, 1, 0.3, 1);
}

/* ---------- Reset ---------- */
*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
body, h1, h2, h3, p, ul, ol, dl, dd, figure, blockquote { margin: 0; }
ul, ol { padding: 0; list-style: none; }
img, picture { display: block; max-width: 100%; }
a { color: inherit; text-decoration: none; }
button { font: inherit; background: none; border: none; cursor: pointer; }
table { border-collapse: collapse; width: 100%; }

body {
  font-family: var(--font-body);
  background: var(--pearl);
  color: var(--black);
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
}

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

/* Focus ring — accent green, visible everywhere */
a:focus-visible,
button:focus-visible,
[tabindex]:focus-visible {
  outline: 2px solid var(--green-glow);
  outline-offset: 3px;
  border-radius: 4px;
}

.wrap {
  width: 100%;
  max-width: 1120px;
  margin-inline: auto;
  padding-inline: var(--space-2);
}

/* ---------- Section rhythm ---------- */
.section {
  position: relative;
  padding-block: var(--space-7);
  overflow: hidden;
}
.section--light { background: var(--pearl); color: var(--black); }
.section--dark { background: var(--black-soft); color: var(--pearl); }

.section__heading {
  font-size: 32px;
  font-weight: 700;
  letter-spacing: -0.02em;
  margin-bottom: var(--space-1);
}
.section__sub {
  color: var(--text-muted-on-light);
  margin-bottom: var(--space-5);
  max-width: 48ch;
}
.section--dark .section__sub { color: var(--text-muted); }

.section__note {
  color: var(--text-muted-on-light);
  font-size: 14px;
  margin-top: var(--space-3);
  max-width: 60ch;
}
.section--dark .section__note { color: var(--text-muted); }

/* Grain overlay for dark sections */
.grain {
  position: absolute;
  inset: 0;
  pointer-events: none;
  opacity: 0.035;
  z-index: 0;
}
.section--dark > .wrap { position: relative; z-index: 1; }

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-btn);
  font-weight: 700;
  font-size: 14px;
  letter-spacing: 0.01em;
  padding: 12px 20px;
  transition: transform 200ms var(--ease-out), filter 200ms var(--ease-out), background-color 200ms var(--ease-out);
  white-space: nowrap;
}
.btn--sm { padding: 8px 16px; font-size: 13px; }
.btn--lg { padding: 16px 28px; font-size: 15px; }

.btn--primary {
  background: var(--green-mid);
  color: var(--pearl);
}
.btn--primary:hover { filter: brightness(1.12); transform: scale(1.02); }
.btn--primary:active { filter: brightness(1.18); transform: scale(0.99); }

.btn--secondary {
  background: transparent;
  color: var(--pearl);
  border: 1px solid rgba(244, 243, 239, 0.35);
}
.btn--secondary:hover { border-color: var(--green-glow); transform: scale(1.02); }
.btn--secondary:active { transform: scale(0.99); }

.hero__actions { display: flex; flex-wrap: wrap; gap: var(--space-2); margin-bottom: var(--space-4); }

/* ---------- Header ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  width: 100%;
  background: linear-gradient(180deg, rgba(11,12,11,0.55) 0%, rgba(11,12,11,0) 100%);
  border-bottom: 1px solid transparent;
  transition: background-color 300ms var(--ease-out), border-color 300ms var(--ease-out);
}
.site-header.is-scrolled {
  background: rgba(11, 12, 11, 0.92);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid rgba(244, 243, 239, 0.08);
}
.site-header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-block: var(--space-3);
}
.site-header__right {
  display: flex;
  align-items: center;
  gap: var(--space-3);
}

.logo {
  display: inline-flex;
  align-items: center;
}
.logo__lockup {
  height: 48px;
  width: auto;
  display: block;
}

.section__kicker {
  height: 28px;
  width: auto;
  display: block;
  margin-bottom: var(--space-2);
}
.hero__kicker { height: 40px; margin-bottom: var(--space-3); }
.contact__kicker { height: 48px; margin: 0 auto var(--space-3); }

.site-nav { display: none; gap: var(--space-4); }
.site-nav a {
  font-size: 14px;
  color: var(--pearl);
  position: relative;
  padding-block: 4px;
}
.site-nav a::after {
  content: '';
  position: absolute;
  left: 0; right: 0; bottom: 0;
  height: 1px;
  background: var(--green-glow);
  transform: scaleX(0);
  transform-origin: right;
  transition: transform 200ms var(--ease-out);
}
.site-nav a:hover::after { transform: scaleX(1); transform-origin: left; }

/* ---------- Hero ---------- */
.hero {
  position: relative;
  min-height: 85vh;
  display: flex;
  align-items: flex-end;
  background: radial-gradient(140% 100% at 20% 0%, var(--green-mid) 0%, var(--green-deep) 45%, var(--black-soft) 100%);
  color: var(--pearl);
  margin-top: -1px; /* sit under sticky header */
}
.hero__bg { position: absolute; inset: 0; z-index: 0; overflow: hidden; }
.hero__img { width: 100%; height: 112%; object-fit: cover; will-change: transform; }
.hero__overlay {
  position: absolute;
  inset: 0;
  z-index: 1;
  background:
    radial-gradient(120% 90% at 15% 0%, rgba(64,145,108,0.28) 0%, rgba(64,145,108,0) 55%),
    linear-gradient(180deg, rgba(11,12,11,0.55) 0%, rgba(11,12,11,0.35) 35%, rgba(18,40,30,0.92) 100%);
}

/* Ambient drifting glow blobs — living background even without a photo */
.hero__ambient {
  position: absolute;
  inset: 0;
  z-index: 2;
  pointer-events: none;
  background:
    radial-gradient(38% 45% at 15% 20%, rgba(64,145,108,0.32) 0%, transparent 70%),
    radial-gradient(32% 40% at 88% 78%, rgba(45,106,79,0.28) 0%, transparent 70%);
  mix-blend-mode: screen;
  animation: hero-ambient-drift 16s ease-in-out infinite alternate;
}
@keyframes hero-ambient-drift {
  0% { transform: translate(0, 0) scale(1); }
  100% { transform: translate(3%, -4%) scale(1.08); }
}

.hero__bg .grain { z-index: 3; }

/* Cursor-tracking spotlight (desktop pointer only, set via JS) */
.hero__glow {
  position: absolute;
  inset: 0;
  z-index: 4;
  pointer-events: none;
  opacity: 0;
  transition: opacity 500ms ease;
  background: radial-gradient(480px circle at var(--mx, 50%) var(--my, 30%), rgba(64,145,108,0.32), transparent 60%);
  mix-blend-mode: screen;
}
.hero__glow.is-active { opacity: 1; }

/* Scan sweep — a slow light pass, echoing a detail scan */
.hero__scanline {
  position: absolute;
  left: 0;
  right: 0;
  top: -5%;
  height: 2px;
  z-index: 5;
  pointer-events: none;
  background: linear-gradient(90deg, transparent, rgba(64,145,108,0.9), transparent);
  box-shadow: 0 0 14px 2px rgba(64,145,108,0.55);
  animation: hero-scan-sweep 7s cubic-bezier(0.65,0,0.35,1) infinite;
}
@keyframes hero-scan-sweep {
  0%   { top: -5%;  opacity: 0; }
  8%   { opacity: 0.75; }
  45%  { opacity: 0.75; }
  55%  { top: 105%; opacity: 0; }
  100% { top: 105%; opacity: 0; }
}

/* HUD corner frame — precision/viewfinder accent */
.hero__frame {
  position: absolute;
  inset: 24px;
  z-index: 6;
  pointer-events: none;
}
.hero__frame-corner {
  position: absolute;
  width: 26px;
  height: 26px;
  border: 0 solid rgba(64,145,108,0.55);
}
.hero__frame-corner--tl { top: 0; left: 0; border-top-width: 2px; border-left-width: 2px; border-top-left-radius: 6px; }
.hero__frame-corner--tr { top: 0; right: 0; border-top-width: 2px; border-right-width: 2px; border-top-right-radius: 6px; }
.hero__frame-corner--bl { bottom: 0; left: 0; border-bottom-width: 2px; border-left-width: 2px; border-bottom-left-radius: 6px; }
.hero__frame-corner--br { bottom: 0; right: 0; border-bottom-width: 2px; border-right-width: 2px; border-bottom-right-radius: 6px; }

.hero__content {
  position: relative;
  z-index: 10;
  padding-bottom: var(--space-7);
  padding-top: var(--space-9);
}
.hero__title {
  font-size: 40px;
  line-height: 1.08;
  font-weight: 700;
  letter-spacing: -0.02em;
  margin-bottom: var(--space-2);
}
.hero__title .reveal-line { display: block; }
.hero__subhead {
  font-size: 16px;
  color: var(--pearl-warm);
  margin-bottom: var(--space-4);
  max-width: 40ch;
}
.hero__trust {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  font-size: 12.5px;
  color: var(--pearl-warm);
}
.hero__trust li {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  padding: 8px 14px;
  border-radius: 999px;
  background: rgba(244,243,239,0.06);
  border: 1px solid rgba(244,243,239,0.14);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
}
.hero__trust-dot {
  width: 7px;
  height: 7px;
  border-radius: 999px;
  background: var(--green-glow);
  flex-shrink: 0;
  animation: hero-status-pulse 2.2s ease-out infinite;
}
@keyframes hero-status-pulse {
  0%   { box-shadow: 0 0 0 0 rgba(64,145,108,0.55); }
  70%  { box-shadow: 0 0 0 8px rgba(64,145,108,0); }
  100% { box-shadow: 0 0 0 0 rgba(64,145,108,0); }
}

/* Subtle breathing glow on the hero's primary CTA */
.hero__actions .btn--primary {
  animation: hero-cta-pulse 2.8s ease-in-out infinite;
}
@keyframes hero-cta-pulse {
  0%, 100% { box-shadow: 0 0 0 0 rgba(64,145,108,0.45); }
  50%      { box-shadow: 0 0 22px 4px rgba(64,145,108,0.35); }
}

/* Hero load-in animation (staggered by line) */
.reveal-line {
  opacity: 0;
  transform: translateY(24px);
  animation: reveal-in 600ms var(--ease-out) forwards;
}
.hero__title .reveal-line:nth-child(1) { animation-delay: 60ms; }
.hero__title .reveal-line:nth-child(2) { animation-delay: 140ms; }
.hero__subhead { animation-delay: 220ms; }
.hero__actions.reveal-line { animation-delay: 300ms; }
.hero__trust.reveal-line { animation-delay: 380ms; }

@keyframes reveal-in {
  to { opacity: 1; transform: translateY(0); }
}

/* ---------- Scroll reveal (IntersectionObserver driven) ---------- */
.reveal {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 600ms var(--ease-out), transform 600ms var(--ease-out);
}
.reveal.is-visible {
  opacity: 1;
  transform: translateY(0);
}

/* ---------- Cards / Services ---------- */
.cards { display: grid; gap: var(--space-3); margin-top: var(--space-2); }
.cards--3 { grid-template-columns: 1fr; }

.card {
  background: var(--pearl-warm);
  border: 1px solid rgba(11,12,11,0.08);
  border-radius: var(--radius-card);
  padding: var(--space-4);
  transition: transform 200ms var(--ease-out), box-shadow 200ms var(--ease-out);
  position: relative;
}
.card:hover {
  transform: translateY(-4px);
  box-shadow: 0 16px 32px rgba(11,12,11,0.10);
}
.card__title { font-size: 19px; font-weight: 700; margin-bottom: 4px; }
.card__price { font-size: 15px; font-weight: 700; color: var(--green-mid); margin-bottom: var(--space-2); }
.card__desc { color: var(--text-muted-on-light); font-size: 14px; margin-bottom: var(--space-2); }
.card__list { display: flex; flex-direction: column; gap: 6px; font-size: 14px; }
.card__list li::before { content: '\2713  '; color: var(--green-mid); }

.card--featured {
  background: var(--pearl);
  border: 1.5px solid var(--green-mid);
}
.card__tag {
  position: absolute;
  top: -12px;
  left: var(--space-4);
  background: var(--green-mid);
  color: var(--pearl);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  padding: 4px 10px;
  border-radius: 999px;
}

/* ---------- Before/After sliders ---------- */
.ba-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-3);
  margin-bottom: var(--space-5);
}

.ba-slider__stage {
  position: relative;
  aspect-ratio: 1 / 1;
  border-radius: var(--radius-card);
  overflow: hidden;
  border: 1px solid rgba(244,243,239,0.12);
  background: rgba(64,145,108,0.10);
  touch-action: pan-y;
  user-select: none;
}
.ba-slider__img { position: absolute; inset: 0; width: 100%; height: 100%; }
.ba-slider__img img { width: 100%; height: 100%; object-fit: cover; }
.ba-slider__img--after { z-index: 0; }

.ba-slider__before-clip {
  position: absolute;
  inset: 0;
  width: 50%;
  overflow: hidden;
  z-index: 1;
}
.ba-slider__before-clip .ba-slider__img { width: var(--stage-w, 100%); }

.ba-slider__divider {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 50%;
  width: 2px;
  background: var(--pearl);
  transform: translateX(-50%);
  z-index: 2;
  cursor: ew-resize;
  display: flex;
  align-items: center;
  justify-content: center;
}
.ba-slider__handle {
  width: 44px;
  height: 44px;
  border-radius: 999px;
  background: var(--pearl);
  border: 2px solid var(--green-glow);
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 4px 16px rgba(0,0,0,0.25);
}
.ba-slider__handle::before {
  content: '\2194';
  color: var(--green-mid);
  font-size: 16px;
  font-weight: 700;
}
.ba-slider__handle.bounce { animation: handle-bounce 1100ms var(--ease-out) 400ms; }
@keyframes handle-bounce {
  0% { transform: translateX(0); }
  30% { transform: translateX(-14px); }
  55% { transform: translateX(10px); }
  75% { transform: translateX(-5px); }
  100% { transform: translateX(0); }
}

.ba-slider__caption {
  margin-top: var(--space-1);
  font-size: 13px;
  color: var(--text-muted);
  text-align: center;
}

.detail-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--space-1);
}
.detail-grid__item {
  aspect-ratio: 1 / 1;
  border-radius: var(--radius-card);
  overflow: hidden;
  border: 1px solid rgba(244,243,239,0.12);
  background: rgba(64,145,108,0.10);
}
.detail-grid__item img { width: 100%; height: 100%; object-fit: cover; }

/* ---------- Pricing table ---------- */
.price-table-wrap { margin-bottom: var(--space-5); }
.price-table {
  display: block;
  background: var(--pearl-warm);
  border: 1px solid rgba(11,12,11,0.08);
  border-radius: var(--radius-card);
  overflow: hidden;
}
.price-table thead { display: none; }
.price-table tbody { display: flex; flex-direction: column; gap: var(--space-2); }
.price-table tr {
  display: block;
  background: var(--pearl);
  border: 1px solid rgba(11,12,11,0.08);
  border-radius: var(--radius-card);
  padding: var(--space-2);
  margin: var(--space-2);
}
.price-table th[scope="row"] {
  display: block;
  font-size: 16px;
  font-weight: 700;
  margin-bottom: var(--space-1);
  text-align: left;
}
.price-table td {
  display: flex;
  justify-content: space-between;
  padding: 6px 0;
  font-size: 14px;
  border-top: 1px solid rgba(11,12,11,0.06);
}
.price-table td::before {
  content: attr(data-label);
  color: var(--text-muted-on-light);
}
.price-table__note {
  font-size: 12px;
  color: var(--text-muted-on-light);
  padding: 0 var(--space-2) var(--space-2);
}

.addons__title { font-size: 18px; font-weight: 700; margin-bottom: var(--space-2); }
.addons__list {
  display: flex;
  flex-direction: column;
  gap: 0;
  border-top: 1px solid rgba(11,12,11,0.08);
}
.addons__list li {
  display: flex;
  justify-content: space-between;
  padding: 12px 0;
  border-bottom: 1px solid rgba(11,12,11,0.08);
  font-size: 14px;
}
.addons__list li span:last-child { font-weight: 700; color: var(--green-mid); }

/* ---------- How it works ---------- */
.steps {
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
  position: relative;
}
.steps__item { position: relative; padding-left: 52px; }
.steps__num {
  position: absolute;
  left: 0; top: 0;
  width: 36px; height: 36px;
  border-radius: 999px;
  background: var(--green-mid);
  color: var(--pearl);
  font-weight: 700;
  font-size: 14px;
  display: flex;
  align-items: center;
  justify-content: center;
}
.steps__item:not(:last-child)::after {
  content: '';
  position: absolute;
  left: 17px;
  top: 40px;
  width: 1px;
  height: calc(100% + var(--space-4) - 40px);
  background: rgba(244,243,239,0.14);
}
.steps__title { font-size: 16px; font-weight: 700; margin-bottom: 2px; }
.steps__desc { font-size: 14px; color: var(--text-muted); }

/* ---------- About ---------- */
.about { display: flex; flex-direction: column; gap: var(--space-4); }
.about__photo picture {
  border-radius: var(--radius-card);
  overflow: hidden;
  aspect-ratio: 4 / 3;
  background: var(--pearl-warm);
}
.about__photo img { width: 100%; height: 100%; object-fit: cover; }
.about__text p { color: var(--text-muted-on-light); margin-top: var(--space-2); max-width: 60ch; }

/* ---------- Contact ---------- */
.section--cta { text-align: center; }
.contact__heading { font-size: 30px; font-weight: 700; letter-spacing: -0.02em; margin-bottom: var(--space-1); }
.contact__sub { color: var(--text-muted); margin-bottom: var(--space-4); }
.contact__details {
  margin-top: var(--space-6);
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
  max-width: 360px;
  margin-inline: auto;
  text-align: left;
}
.contact__row {
  display: flex;
  justify-content: space-between;
  gap: var(--space-2);
  border-bottom: 1px solid rgba(244,243,239,0.10);
  padding-bottom: var(--space-1);
  font-size: 14px;
}
.contact__row dt { color: var(--text-muted); }
.contact__row dd a { color: var(--green-glow); }
.contact__row dd a:hover { text-decoration: underline; }

/* ---------- Footer ---------- */
.site-footer {
  background: var(--black);
  color: var(--text-muted);
  padding-block: var(--space-4);
}
.site-footer__inner {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-1);
  text-align: center;
}
.logo--footer .logo__lockup { height: 30px; }
.site-footer__copy, .site-footer__tag { font-size: 12px; }

/* ==========================================================================
   Tablet / Desktop
   ========================================================================== */
@media (min-width: 640px) {
  .cards--3 { grid-template-columns: repeat(3, 1fr); }
  .ba-grid--2 { grid-template-columns: repeat(2, 1fr); }
  .detail-grid { grid-template-columns: repeat(3, 1fr); }
  .about { flex-direction: row; align-items: center; }
  .about__photo, .about__text { flex: 1; }
}

@media (min-width: 900px) {
  .site-nav { display: flex; align-items: center; }
  .hero { min-height: 100vh; }
  .hero__title { font-size: 56px; }
  .hero__subhead { font-size: 18px; }
  .section__heading { font-size: 38px; }

  .price-table { display: table; }
  .price-table thead { display: table-header-group; }
  .price-table tbody { display: table-row-group; }
  .price-table tr { display: table-row; background: none; border: none; margin: 0; padding: 0; }
  .price-table th, .price-table td { display: table-cell; padding: 14px 20px; border-top: 1px solid rgba(11,12,11,0.08); border-bottom: none; vertical-align: middle; }
  .price-table th[scope="row"] { display: table-cell; margin-bottom: 0; }
  .price-table thead th { padding: 14px 20px; font-size: 13px; text-transform: uppercase; letter-spacing: 0.04em; color: var(--text-muted-on-light); border-top: none; text-align: left; }
  .price-table td::before { content: none; }
  .price-table td { display: table-cell; justify-content: flex-start; font-weight: 600; }

  .steps { flex-direction: row; }
  .steps__item { flex: 1; padding-left: 0; padding-top: 52px; }
  .steps__num { left: 50%; transform: translateX(-50%); }
  .steps__item:not(:last-child)::after {
    left: calc(50% + 18px);
    top: 17px;
    width: calc(100% - 36px);
    height: 1px;
  }
  .steps__title, .steps__desc { text-align: center; }
}

@media (min-width: 1100px) {
  .hero__title { font-size: 64px; }
}

/* ==========================================================================
   Reduced motion
   ========================================================================== */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
  .reveal, .reveal-line { opacity: 1 !important; transform: none !important; }
  .card:hover, .btn:hover { transform: none !important; }
}