/* ==========================================================================
   CH4 Engineering & Consultants — stylesheet
   Plain CSS, mobile-first. Palette derived from the CH4 logo.
   Edit the custom properties below to retheme the whole site at once.
   ========================================================================== */

:root {
  /* Brand palette (from the logo) */
  --amber:        #F2A03A;   /* shield top — primary accent */
  --amber-deep:   #E07B1E;   /* shield base — CTA gradient end */
  --steel:        #54565A;   /* the metal "CH4" — secondary text/UI */
  --charcoal:     #1C1C1C;   /* dark sections, headings */
  --charcoal-2:   #2A2B2E;   /* dark-section gradient partner */
  --wash:         #FBE7CC;   /* light amber wash */
  --mist:         #F6F6F4;   /* off-white section bg */
  --white:        #FFFFFF;

  /* Functional tokens */
  --ink:          #1C1C1C;   /* default body text */
  --ink-soft:     #5A5C60;   /* muted text */
  --line:         #E6E5E1;   /* hairline borders */
  --bg:           var(--white);

  --radius:       14px;
  --radius-sm:    10px;
  --shadow:       0 1px 2px rgba(28,28,28,.06), 0 8px 24px rgba(28,28,28,.07);
  --shadow-lg:    0 18px 50px rgba(28,28,28,.16);
  --maxw:         1140px;
  --header-h:     72px;

  --font: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Arial, Helvetica, sans-serif;
}

/* ---------- Reset / base ---------- */
*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: var(--header-h); }
@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; } }

body {
  margin: 0;
  font-family: var(--font);
  color: var(--ink);
  background: var(--bg);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

img, svg { display: block; max-width: 100%; }
a { color: var(--amber-deep); }

h1, h2, h3 { line-height: 1.15; letter-spacing: -0.02em; margin: 0 0 .5em; }
h1 { font-size: clamp(2rem, 5.2vw, 3.5rem); font-weight: 800; }
h2 { font-size: clamp(1.6rem, 3.6vw, 2.4rem); font-weight: 800; }
h3 { font-size: 1.2rem; font-weight: 700; }
p  { margin: 0 0 1rem; }

.container { width: 100%; max-width: var(--maxw); margin-inline: auto; padding-inline: 22px; }

/* Accessibility helpers */
.skip-link {
  position: absolute; left: -999px; top: 0; z-index: 1000;
  background: var(--charcoal); color: #fff; padding: 10px 16px; border-radius: 0 0 8px 0;
}
.skip-link:focus { left: 0; }

:focus-visible {
  outline: 3px solid var(--amber);
  outline-offset: 2px;
  border-radius: 4px;
}

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex; align-items: center; justify-content: center;
  font-weight: 700; font-size: .98rem;
  padding: 13px 26px; border-radius: 999px;
  text-decoration: none; cursor: pointer; border: 2px solid transparent;
  transition: transform .15s ease, box-shadow .2s ease, background .2s ease, color .2s ease;
}
.btn-primary {
  color: #fff;
  background: linear-gradient(135deg, var(--amber), var(--amber-deep));
  box-shadow: 0 8px 20px rgba(224,123,30,.32);
}
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 12px 26px rgba(224,123,30,.4); }
.btn-ghost {
  color: var(--charcoal); border-color: rgba(28,28,28,.22); background: transparent;
}
.btn-ghost:hover { border-color: var(--amber-deep); color: var(--amber-deep); transform: translateY(-2px); }

/* ==========================================================================
   HEADER
   ========================================================================== */
.site-header {
  position: sticky; top: 0; z-index: 100;
  background: rgba(255,255,255,.88);
  backdrop-filter: saturate(160%) blur(12px);
  border-bottom: 1px solid var(--line);
}
.header-inner {
  display: flex; align-items: center; justify-content: space-between;
  height: var(--header-h);
}
.brand { display: flex; align-items: center; gap: 12px; text-decoration: none; color: var(--charcoal); }
.brand-logo { height: 46px; width: auto; }
.brand-text { display: flex; flex-direction: column; line-height: 1.05; }
.brand-text strong { font-size: 1.32rem; font-weight: 800; letter-spacing: -.02em; }
.brand-text small { font-size: .66rem; text-transform: uppercase; letter-spacing: .12em; color: var(--steel); }

.nav { display: flex; align-items: center; }
.nav-menu {
  list-style: none; display: flex; align-items: center; gap: 6px; margin: 0; padding: 0;
}
.nav-menu a {
  display: inline-block; text-decoration: none; color: var(--steel); font-weight: 600;
  padding: 9px 14px; border-radius: 8px; font-size: .96rem;
  transition: color .15s ease, background .15s ease;
}
.nav-menu a:hover { color: var(--charcoal); background: var(--mist); }
.nav-cta {
  color: #fff !important;
  background: linear-gradient(135deg, var(--amber), var(--amber-deep));
  box-shadow: 0 6px 14px rgba(224,123,30,.28);
}
.nav-cta:hover { background: linear-gradient(135deg, var(--amber-deep), var(--amber-deep)) !important; transform: translateY(-1px); }

/* Hamburger */
.nav-toggle {
  display: none; width: 44px; height: 44px; border: 0; background: transparent;
  cursor: pointer; padding: 10px; border-radius: 8px;
}
.nav-toggle span {
  display: block; height: 2.5px; background: var(--charcoal); border-radius: 2px;
  margin: 4px 0; transition: transform .25s ease, opacity .2s ease;
}
.nav-toggle[aria-expanded="true"] span:nth-child(1) { transform: translateY(6.5px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] span:nth-child(2) { opacity: 0; }
.nav-toggle[aria-expanded="true"] span:nth-child(3) { transform: translateY(-6.5px) rotate(-45deg); }

@media (max-width: 820px) {
  .nav-toggle { display: block; }
  .nav-menu {
    position: fixed; inset: var(--header-h) 0 auto 0;
    flex-direction: column; align-items: stretch; gap: 0;
    background: #fff; border-bottom: 1px solid var(--line);
    padding: 10px 18px 18px; box-shadow: var(--shadow-lg);
    transform: translateY(-130%); transition: transform .3s ease;
  }
  .nav-menu.open { transform: translateY(0); }
  .nav-menu li { width: 100%; }
  .nav-menu a { display: block; padding: 14px 12px; font-size: 1.05rem; border-radius: 10px; }
  .nav-cta { text-align: center; margin-top: 6px; }
}

/* ==========================================================================
   HERO
   ========================================================================== */
.hero { position: relative; color: #fff; overflow: hidden; }
/*
  Hero background = dark overlay + amber glow OVER a photo, with a solid
  gradient as the bottom fallback (shown if the photo is missing).
  To change the photo, swap assets/hero-platform.jpg (keep the name or edit here).
*/
.hero-bg {
  position: absolute; inset: 0; z-index: 0;
  background:
    linear-gradient(160deg, rgba(28,28,28,.86), rgba(28,28,28,.60) 50%, rgba(28,28,28,.80)),
    radial-gradient(1100px 500px at 80% -10%, rgba(242,160,58,.28), transparent 60%),
    url("../assets/hero-platform.jpg") center / cover no-repeat,
    linear-gradient(160deg, var(--charcoal), var(--charcoal-2));
}
/* subtle "pipeline grid" texture */
.hero-bg::after {
  content: ""; position: absolute; inset: 0; opacity: .5;
  background-image:
    linear-gradient(rgba(255,255,255,.035) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255,255,255,.035) 1px, transparent 1px);
  background-size: 46px 46px;
  -webkit-mask-image: radial-gradient(120% 100% at 70% 0%, #000 35%, transparent 80%);
          mask-image: radial-gradient(120% 100% at 70% 0%, #000 35%, transparent 80%);
}
.hero-inner { position: relative; z-index: 1; padding: clamp(64px, 11vw, 132px) 0 clamp(48px, 7vw, 80px); }

.eyebrow {
  display: inline-block; text-transform: uppercase; letter-spacing: .22em;
  font-size: .8rem; font-weight: 700; color: var(--amber);
  margin: 0 0 18px; padding: 7px 14px; border: 1px solid rgba(242,160,58,.4);
  border-radius: 999px; background: rgba(242,160,58,.08);
}
.hero h1 { max-width: 16ch; color: #fff; }
.hero h1 .accent {
  background: linear-gradient(120deg, var(--amber), var(--amber-deep));
  -webkit-background-clip: text; background-clip: text; color: transparent;
}
.hero-lead { max-width: 52ch; font-size: clamp(1.05rem, 1.6vw, 1.25rem); color: #D9DADD; margin-bottom: 30px; }
.hero-cta { display: flex; flex-wrap: wrap; gap: 14px; }
.hero-cta .btn-ghost { color: #fff; border-color: rgba(255,255,255,.32); }
.hero-cta .btn-ghost:hover { border-color: var(--amber); color: var(--amber); }

/* Stat row */
.stats {
  list-style: none; margin: clamp(40px, 6vw, 64px) 0 0; padding: 26px 0 0;
  border-top: 1px solid rgba(255,255,255,.14);
  display: grid; grid-template-columns: repeat(4, 1fr); gap: 22px;
}
.stats li { display: flex; flex-direction: column; gap: 4px; }
.stat-num {
  font-size: clamp(1.5rem, 3vw, 2.1rem); font-weight: 800; color: var(--amber);
  letter-spacing: -.02em; line-height: 1;
}
.stat-label { font-size: .85rem; color: #B9BBBE; }
@media (max-width: 700px) { .stats { grid-template-columns: repeat(2, 1fr); gap: 24px 18px; } }

/* ==========================================================================
   SECTIONS — shared
   ========================================================================== */
.section { padding: clamp(56px, 8vw, 104px) 0; }
.section--mist { background: var(--mist); }
.section--dark {
  background: linear-gradient(160deg, var(--charcoal), var(--charcoal-2));
  color: #fff;
}
.section--dark h2, .section--dark p { color: #fff; }
.section--dark .section-sub { color: #B9BBBE; }

.kicker {
  text-transform: uppercase; letter-spacing: .18em; font-size: .78rem; font-weight: 700;
  color: var(--amber-deep); margin: 0 0 10px;
}
.section--dark .kicker { color: var(--amber); }
.section-head { max-width: 720px; margin: 0 0 clamp(32px, 5vw, 52px); }
.section-sub { color: var(--ink-soft); font-size: 1.08rem; }

/* ---------- About ---------- */
.about-grid { display: grid; grid-template-columns: 1.3fr 1fr; gap: clamp(30px, 5vw, 64px); align-items: center; }
.about-copy .kicker { margin-top: 0; }
@media (max-width: 860px) { .about-grid { grid-template-columns: 1fr; } }
.about-media { margin: 0; }
.about-img {
  width: 100%; height: 100%; min-height: 340px; object-fit: cover;
  border-radius: var(--radius); box-shadow: var(--shadow-lg);
}

/* Image placeholder slots */
.img-slot {
  position: relative; background:
    repeating-linear-gradient(45deg, rgba(84,86,90,.06) 0 12px, rgba(84,86,90,.10) 12px 24px);
  border: 2px dashed rgba(84,86,90,.35); border-radius: var(--radius);
  color: var(--steel); display: grid; place-items: center; min-height: 220px;
}
.img-slot::after {
  content: attr(data-hint); position: absolute; bottom: 12px;
  font-size: .78rem; letter-spacing: .04em; color: var(--steel); opacity: .85;
}
.img-slot--tall { min-height: 340px; }
.img-slot-ico { width: 72px; height: 72px; color: var(--amber-deep); opacity: .8; }

/* ---------- Services cards ---------- */
.cards { display: grid; grid-template-columns: repeat(3, 1fr); gap: 22px; }
@media (max-width: 920px) { .cards { grid-template-columns: repeat(2, 1fr); } }
@media (max-width: 600px) { .cards { grid-template-columns: 1fr; } }

.card {
  position: relative; background: #fff; border: 1px solid var(--line);
  border-radius: var(--radius); padding: 30px 26px 26px;
  box-shadow: var(--shadow);
  transition: transform .2s ease, box-shadow .2s ease, border-color .2s ease;
  overflow: hidden;
}
.card::before {
  content: ""; position: absolute; left: 0; top: 0; height: 4px; width: 100%;
  background: linear-gradient(90deg, var(--amber), var(--amber-deep));
  transform: scaleX(0); transform-origin: left; transition: transform .3s ease;
}
.card:hover { transform: translateY(-6px); box-shadow: var(--shadow-lg); border-color: transparent; }
.card:hover::before { transform: scaleX(1); }
.card-num {
  font-size: .82rem; font-weight: 800; color: var(--amber-deep);
  letter-spacing: .12em; display: block; margin-bottom: 10px;
}
.card h3 { margin-bottom: .5rem; }
.card p { color: var(--ink-soft); margin: 0; font-size: .98rem; }
.card a { font-weight: 600; }

/* ---------- Experts ---------- */
.experts { display: grid; grid-template-columns: 1fr 1fr; gap: 26px; }
@media (max-width: 820px) { .experts { grid-template-columns: 1fr; } }
.expert {
  display: grid; grid-template-columns: 120px 1fr; gap: 24px;
  background: #fff; border: 1px solid var(--line); border-radius: var(--radius);
  padding: 28px; box-shadow: var(--shadow);
  transition: transform .2s ease, box-shadow .2s ease;
}
.expert:hover { transform: translateY(-4px); box-shadow: var(--shadow-lg); }
.expert-photo {
  width: 120px; height: 120px; min-height: 0; border-radius: 50%;
  border: 3px solid var(--wash);
  background: linear-gradient(160deg, var(--charcoal), var(--steel));
  display: grid; place-items: center;
}
.expert-photo::after { content: none; }
.expert-initials { font-size: 2rem; font-weight: 800; color: var(--amber); letter-spacing: .02em; }
.expert-body h3 { margin-bottom: 2px; }
.expert-role { color: var(--amber-deep); font-weight: 700; font-size: .95rem; margin: 0 0 .7rem; }
.expert-body p { color: var(--ink-soft); font-size: .96rem; }
.tags { list-style: none; display: flex; flex-wrap: wrap; gap: 8px; padding: 0; margin: 14px 0 0; }
.tags li {
  font-size: .78rem; font-weight: 600; color: var(--steel);
  background: var(--mist); border: 1px solid var(--line);
  padding: 5px 11px; border-radius: 999px;
}
@media (max-width: 460px) {
  .expert { grid-template-columns: 1fr; justify-items: center; text-align: center; }
  .tags { justify-content: center; }
}

/* ---------- Clients / experience ---------- */
.clients {
  list-style: none; padding: 0; margin: 0;
  display: grid; grid-template-columns: repeat(2, 1fr); gap: 18px;
}
@media (max-width: 720px) { .clients { grid-template-columns: 1fr; } }
.clients li {
  background: rgba(255,255,255,.04); border: 1px solid rgba(255,255,255,.12);
  border-left: 3px solid var(--amber); border-radius: var(--radius-sm);
  padding: 18px 20px; transition: background .2s ease, transform .2s ease;
}
.clients li:hover { background: rgba(242,160,58,.10); transform: translateX(4px); }
.clients strong { display: block; color: #fff; font-size: 1.05rem; margin-bottom: 3px; }
.clients span { color: #B9BBBE; font-size: .92rem; }

/* ---------- Contact ---------- */
.contact-grid { display: grid; grid-template-columns: 1fr 1.1fr; gap: clamp(30px, 5vw, 60px); align-items: start; }
@media (max-width: 860px) { .contact-grid { grid-template-columns: 1fr; } }
.contact-list { list-style: none; padding: 0; margin: 22px 0 0; display: grid; gap: 12px; }
.contact-list li { display: flex; align-items: center; gap: 12px; font-size: 1.05rem; }
.contact-ico {
  display: grid; place-items: center; width: 38px; height: 38px; border-radius: 10px;
  background: var(--wash); color: var(--amber-deep); font-size: 1.1rem;
}
.contact-list a { color: var(--charcoal); text-decoration: none; font-weight: 600; }
.contact-list a:hover { color: var(--amber-deep); }

.contact-form {
  background: #fff; border: 1px solid var(--line); border-radius: var(--radius);
  padding: 30px; box-shadow: var(--shadow);
}
.field { margin-bottom: 18px; }
.field label { display: block; font-weight: 600; font-size: .92rem; margin-bottom: 7px; color: var(--charcoal); }
.field input, .field textarea {
  width: 100%; font: inherit; color: var(--ink);
  padding: 12px 14px; border: 1.5px solid var(--line); border-radius: var(--radius-sm);
  background: var(--mist); transition: border-color .15s ease, background .15s ease, box-shadow .15s ease;
}
.field input:focus, .field textarea:focus {
  outline: none; border-color: var(--amber); background: #fff;
  box-shadow: 0 0 0 3px rgba(242,160,58,.18);
}
.field textarea { resize: vertical; }
.hp { position: absolute; left: -9999px; }
.contact-form .btn { width: 100%; margin-top: 4px; }
.form-status { margin: 14px 0 0; font-weight: 600; font-size: .95rem; min-height: 1.2em; }
.form-status.ok  { color: #1a7f4b; }
.form-status.err { color: #b3261e; }

/* ==========================================================================
   FOOTER
   ========================================================================== */
.site-footer { background: var(--charcoal); color: #C9CBCE; padding: 26px 0; }
.footer-inner { display: flex; align-items: center; justify-content: space-between; gap: 16px; flex-wrap: wrap; }
.footer-copy { margin: 0; font-size: .92rem; }
.footer-linkedin {
  display: grid; place-items: center; width: 40px; height: 40px; border-radius: 10px;
  color: #C9CBCE; background: rgba(255,255,255,.06); transition: background .2s ease, color .2s ease;
}
.footer-linkedin:hover { background: var(--amber); color: var(--charcoal); }

/* ==========================================================================
   SCROLL-REVEAL animations (progressive — content is visible without JS)
   ========================================================================== */
.reveal { opacity: 0; transform: translateY(22px); transition: opacity .6s ease, transform .6s ease; }
.reveal.is-visible { opacity: 1; transform: none; }
/* Respect reduced-motion and no-JS: show everything */
@media (prefers-reduced-motion: reduce) { .reveal { opacity: 1; transform: none; transition: none; } }
.no-js .reveal { opacity: 1; transform: none; }