/* ==========================================================================
   V1 Energy Solutions — site stylesheet (V3)
   System font stack: fast, private (no third-party font requests).
   Palette: navy brand + emerald accent. Chart colours validated for
   colour-vision safety (light: #2A62B0/#0E9F6E · dark: #4E86D8/#1CA878).
   ========================================================================== */

:root {
  --navy-900: #06101f;
  --navy-800: #0a1a30;   /* brand */
  --navy-700: #122a4c;
  --navy-600: #1d3a63;
  --navy-tint: #eaf0f7;
  --paper: #ffffff;
  --paper-2: #f6f8fb;
  --ink: #17273c;
  --ink-2: #47566b;
  --ink-3: #66758a;
  --line: #dfe5ec;
  --green-800: #0a6b4a;
  --green-700: #0b7a54;   /* buttons / links on light (white text 4.9:1) */
  --green-600: #0e9f6e;   /* data accent on light */
  --green-300: #2bc48e;   /* links on navy */
  --blue-series: #2a62b0; /* "before" series on light */
  --amber: #b45309;
  --radius: 14px;
  --radius-sm: 8px;
  --shadow: 0 1px 2px rgba(10, 26, 48, 0.06), 0 8px 24px rgba(10, 26, 48, 0.08);
  --wrap: 1120px;
  --font: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: var(--font);
  font-size: 17px;
  line-height: 1.6;
  color: var(--ink);
  background: var(--paper);
  -webkit-text-size-adjust: 100%;
}
img, svg { max-width: 100%; height: auto; }
a { color: var(--green-700); text-decoration-thickness: 1px; text-underline-offset: 2px; }
a:hover { color: var(--green-800); }
h1, h2, h3, h4 { line-height: 1.2; color: var(--navy-800); margin: 0 0 0.5em; font-weight: 700; letter-spacing: -0.01em; }
h1 { font-size: clamp(1.9rem, 4.5vw, 3rem); }
h2 { font-size: clamp(1.45rem, 3vw, 2.1rem); }
h3 { font-size: 1.2rem; }
p { margin: 0 0 1em; }
.small { font-size: 0.88rem; color: var(--ink-3); }
.lead { font-size: 1.14rem; color: var(--ink-2); }
.wrap { max-width: var(--wrap); margin: 0 auto; padding: 0 20px; }
.section { padding: 56px 0; }
.section.tight { padding: 36px 0; }
.section.alt { background: var(--paper-2); }
.center { text-align: center; }
.eyebrow {
  display: inline-block; font-size: 0.8rem; font-weight: 700; letter-spacing: 0.08em;
  text-transform: uppercase; color: var(--green-700); margin-bottom: 10px;
}
.on-dark .eyebrow { color: var(--green-300); }

/* Skip link */
.skip-link {
  position: absolute; left: -9999px; top: 0; background: var(--navy-800); color: #fff;
  padding: 10px 16px; z-index: 100; border-radius: 0 0 8px 0;
}
.skip-link:focus { left: 0; }

/* ------------------------------------------------------------------ header */
.topbar {
  background: var(--navy-900); color: #cdd8e6; font-size: 0.85rem;
}
.topbar .wrap { display: flex; justify-content: space-between; align-items: center; padding-top: 6px; padding-bottom: 6px; gap: 12px; }
.topbar a { color: #e8eef6; }
.topbar .phone-chip { color: #e8eef6; font-weight: 600; white-space: nowrap; }

header.site {
  position: sticky; top: 0; z-index: 50;
  background: var(--navy-800); color: #fff;
  box-shadow: 0 1px 0 rgba(255,255,255,0.08);
}
header.site .wrap { display: flex; align-items: center; gap: 18px; padding-top: 12px; padding-bottom: 12px; }
.logo { display: flex; align-items: center; gap: 10px; text-decoration: none; color: #fff; font-weight: 800; font-size: 1.05rem; letter-spacing: 0.01em; }
.logo .mark { width: 34px; height: 34px; flex: none; }
.logo .word { white-space: nowrap; }
.logo .word small { display: block; font-size: 0.66rem; font-weight: 600; letter-spacing: 0.14em; color: #9db2cc; text-transform: uppercase; }

nav.primary { margin-left: auto; }
nav.primary ul { list-style: none; display: flex; gap: 4px; margin: 0; padding: 0; align-items: center; }
nav.primary a {
  display: block; padding: 8px 12px; color: #dbe4f0; text-decoration: none;
  border-radius: 8px; font-size: 0.95rem; font-weight: 600; white-space: nowrap;
}
nav.primary a:hover { background: var(--navy-700); color: #fff; }
nav.primary a[aria-current="page"] { background: var(--navy-700); color: #fff; }
.nav-cta {
  background: var(--green-700) !important; color: #fff !important; margin-left: 6px;
}
.nav-cta:hover { background: var(--green-800) !important; }
.nav-login { border: 1px solid #405270 !important; }
.nav-login:hover { border-color: #7d91af !important; }
.nav-toggle {
  display: none; margin-left: auto; background: none; border: 1px solid #405270;
  color: #fff; border-radius: 8px; padding: 8px 12px; font: inherit; cursor: pointer;
}

/* ------------------------------------------------------------------- hero */
.hero { background: linear-gradient(180deg, var(--navy-800) 0%, var(--navy-900) 100%); color: #e8eef6; }
.hero .wrap { display: grid; grid-template-columns: 1.15fr 0.85fr; gap: 44px; align-items: center; padding-top: 64px; padding-bottom: 64px; }
.hero h1 { color: #fff; margin-bottom: 0.4em; }
.hero .lead { color: #b9c7da; }
.hero .actions { display: flex; gap: 12px; flex-wrap: wrap; margin-top: 22px; }
.hero .note { margin-top: 18px; font-size: 0.88rem; color: #8fa2bb; }

.btn {
  display: inline-block; padding: 12px 22px; border-radius: 10px; font-weight: 700;
  text-decoration: none; font-size: 1rem; border: 1px solid transparent;
}
.btn.primary { background: var(--green-700); color: #fff; }
.btn.primary:hover { background: var(--green-800); color: #fff; }
.btn.ghost { border-color: #46587a; color: #e8eef6; }
.btn.ghost:hover { border-color: #7d91af; color: #fff; }
.btn.ghost.on-light { border-color: var(--navy-600); color: var(--navy-800); }
.btn.ghost.on-light:hover { background: var(--navy-tint); }

/* data panel (hero, dark surface) */
.data-panel {
  background: rgba(255, 255, 255, 0.045);
  border: 1px solid rgba(255, 255, 255, 0.12);
  border-radius: var(--radius); padding: 22px 22px 16px;
}
.data-panel h3 { color: #fff; font-size: 0.98rem; margin-bottom: 2px; }
.data-panel .sub { font-size: 0.82rem; color: #93a6bf; margin-bottom: 14px; }
.data-panel .foot { font-size: 0.78rem; color: #8095b0; margin-top: 10px; }
.legend { display: flex; gap: 16px; font-size: 0.8rem; margin-top: 8px; }
.legend .key { display: inline-flex; align-items: center; gap: 6px; color: var(--ink-2); }
.legend .key i { width: 10px; height: 10px; border-radius: 3px; display: inline-block; }
.data-panel .legend .key { color: #b9c7da; }

/* ------------------------------------------------------------- stat tiles */
.stats { display: grid; grid-template-columns: repeat(4, 1fr); gap: 14px; }
.stat {
  background: var(--paper); border: 1px solid var(--line); border-radius: var(--radius);
  padding: 18px 18px 14px;
}
.stat .label { font-size: 0.85rem; color: var(--ink-3); }
.stat .value { font-size: 2rem; font-weight: 700; color: var(--navy-800); line-height: 1.1; margin: 2px 0; }
.stat .value .unit { font-size: 1.1rem; font-weight: 700; color: var(--ink-2); }
.stat .context { font-size: 0.82rem; color: var(--ink-3); }
.stat.accent .value { color: var(--green-700); }

/* ------------------------------------------------------------------ cards */
.grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; }
.grid-4 { display: grid; grid-template-columns: repeat(4, 1fr); gap: 16px; }
.grid-2 { display: grid; grid-template-columns: 1fr 1fr; gap: 24px; }
.card {
  background: var(--paper); border: 1px solid var(--line); border-radius: var(--radius);
  padding: 24px; box-shadow: none;
}
.card.lift { box-shadow: var(--shadow); border-color: transparent; }
.card h3 a { color: var(--navy-800); text-decoration: none; }
.card h3 a:hover { color: var(--green-800); text-decoration: underline; }
.card .kpi { font-size: 1.7rem; font-weight: 800; color: var(--green-700); }
.step-num {
  width: 34px; height: 34px; border-radius: 50%; background: var(--navy-800); color: #fff;
  display: flex; align-items: center; justify-content: center; font-weight: 700; margin-bottom: 12px;
}
.tag {
  display: inline-block; background: var(--navy-tint); color: var(--navy-700);
  font-size: 0.76rem; font-weight: 700; padding: 3px 10px; border-radius: 999px;
  letter-spacing: 0.02em;
}
.tag.green { background: #e3f4ec; color: var(--green-800); }

/* ------------------------------------------------------------ photo slots */
.photo-slot {
  border: 2px dashed #b9c5d4; border-radius: var(--radius); background: var(--paper-2);
  display: flex; flex-direction: column; align-items: center; justify-content: center;
  min-height: 260px; color: var(--ink-3); text-align: center; padding: 24px; gap: 6px;
}
.photo-slot strong { color: var(--ink-2); }

/* --------------------------------------------------------------- evidence */
.evidence {
  border-left: 4px solid var(--green-600); background: var(--paper-2);
  padding: 18px 22px; border-radius: 0 var(--radius-sm) var(--radius-sm) 0; margin: 24px 0;
}
.evidence p:last-child { margin-bottom: 0; }

blockquote.testimonial {
  margin: 24px 0; padding: 20px 24px; background: var(--paper-2);
  border-left: 4px solid var(--navy-600); border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  font-size: 1.05rem; color: var(--ink);
}
blockquote.testimonial footer { font-size: 0.88rem; color: var(--ink-3); margin-top: 8px; }

/* ------------------------------------------------------------------ chart */
figure.chart { margin: 0; }
figure.chart figcaption { font-size: 0.82rem; color: var(--ink-3); margin-top: 8px; }

/* ------------------------------------------------------------------- FAQ */
details.faq { border-bottom: 1px solid var(--line); padding: 4px 0; }
details.faq summary {
  cursor: pointer; font-weight: 700; color: var(--navy-800); padding: 12px 0;
  list-style: none; display: flex; justify-content: space-between; align-items: center; gap: 12px;
}
details.faq summary::-webkit-details-marker { display: none; }
details.faq summary::after { content: "+"; font-size: 1.3rem; color: var(--green-700); flex: none; }
details.faq[open] summary::after { content: "\2212"; }
details.faq .answer { padding: 0 0 14px; color: var(--ink-2); }

/* ------------------------------------------------------------------ forms */
form.contact { display: grid; gap: 14px; }
form.contact .row { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; }
form.contact label { font-weight: 600; font-size: 0.92rem; color: var(--navy-800); display: block; margin-bottom: 5px; }
form.contact input, form.contact textarea, form.contact select {
  width: 100%; padding: 11px 12px; border: 1px solid #c3ccd8; border-radius: var(--radius-sm);
  font: inherit; color: var(--ink); background: #fff;
}
form.contact input:focus, form.contact textarea:focus, form.contact select:focus {
  outline: 2px solid var(--green-600); outline-offset: 1px; border-color: var(--green-600);
}
.hidden-field { position: absolute; left: -9999px; }

/* --------------------------------------------------------------- CTA band */
.cta-band { background: var(--navy-800); color: #dbe4f0; }
.cta-band .wrap { display: flex; align-items: center; justify-content: space-between; gap: 24px; padding-top: 40px; padding-bottom: 40px; flex-wrap: wrap; }
.cta-band h2 { color: #fff; margin: 0 0 6px; }
.cta-band p { margin: 0; color: #a9bad1; }

/* ----------------------------------------------------------------- footer */
footer.site { background: var(--navy-900); color: #9db0c8; font-size: 0.92rem; }
footer.site .wrap { padding-top: 44px; padding-bottom: 28px; }
footer.site .cols { display: grid; grid-template-columns: 1.4fr 1fr 1fr 1.2fr; gap: 28px; }
footer.site h4 { color: #fff; font-size: 0.95rem; margin-bottom: 10px; }
footer.site ul { list-style: none; margin: 0; padding: 0; }
footer.site li { margin-bottom: 7px; }
footer.site a { color: #c4d2e4; text-decoration: none; }
footer.site a:hover { color: #fff; text-decoration: underline; }
.trust-row {
  display: flex; gap: 10px; flex-wrap: wrap; align-items: center;
  border-top: 1px solid #1b2c47; margin-top: 28px; padding-top: 20px;
}
.trust-badge {
  border: 1px solid #2a3f61; color: #b9c7da; border-radius: 8px; padding: 6px 12px;
  font-size: 0.78rem; font-weight: 600; letter-spacing: 0.02em;
}
.legal-row { border-top: 1px solid #1b2c47; margin-top: 20px; padding-top: 16px; font-size: 0.8rem; color: #7185a0; }
.legal-row p { margin: 0 0 4px; }

/* ------------------------------------------------------------ breadcrumbs */
.crumbs { font-size: 0.85rem; color: var(--ink-3); padding: 18px 0 0; }
.crumbs a { color: var(--ink-3); }
.crumbs a:hover { color: var(--green-800); }

/* ---------------------------------------------------------------- article */
article.post { max-width: 760px; margin: 0 auto; }
article.post .meta { color: var(--ink-3); font-size: 0.9rem; margin-bottom: 24px; }
article.post h2 { margin-top: 1.6em; }
article.post h3 { margin-top: 1.4em; }
article.post .standfirst { font-size: 1.16rem; color: var(--ink-2); }
.post-card { display: flex; flex-direction: column; gap: 8px; }
.post-card .date { font-size: 0.82rem; color: var(--ink-3); }
.disclaimer { font-size: 0.85rem; color: var(--ink-3); border-top: 1px solid var(--line); padding-top: 14px; margin-top: 28px; }

/* ---------------------------------------------------------------- tables */
table.clean { border-collapse: collapse; width: 100%; font-size: 0.95rem; }
table.clean th, table.clean td { text-align: left; padding: 10px 12px; border-bottom: 1px solid var(--line); }
table.clean th { color: var(--navy-800); font-size: 0.85rem; letter-spacing: 0.03em; text-transform: uppercase; }

/* ------------------------------------------------------------- responsive */
@media (max-width: 900px) {
  .hero .wrap { grid-template-columns: 1fr; gap: 30px; }
  .stats { grid-template-columns: repeat(2, 1fr); }
  .grid-3 { grid-template-columns: 1fr; }
  .grid-4 { grid-template-columns: repeat(2, 1fr); }
  .grid-2 { grid-template-columns: 1fr; }
  footer.site .cols { grid-template-columns: 1fr 1fr; }
  form.contact .row { grid-template-columns: 1fr; }
  .nav-toggle { display: block; }
  nav.primary {
    display: none; position: absolute; top: 100%; left: 0; right: 0;
    background: var(--navy-800); border-top: 1px solid var(--navy-700);
    box-shadow: 0 16px 24px rgba(6, 16, 31, 0.35);
  }
  nav.primary.open { display: block; }
  nav.primary ul { flex-direction: column; align-items: stretch; padding: 10px 16px 16px; }
  nav.primary a { padding: 12px; }
  .topbar .tagline { display: none; }
}
@media (max-width: 520px) {
  .stats { grid-template-columns: 1fr; }
  .grid-4 { grid-template-columns: 1fr; }
  footer.site .cols { grid-template-columns: 1fr; }
}

/* Reduced motion */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
}

/* ------------------------------------------- case study hero (photo bg) */
.cs-hero {
  position: relative;
  background-color: var(--navy-800);
  background-size: cover;
  background-position: center;
  color: #e8eef6;
  overflow: hidden;
}
.cs-hero::before {
  content: "";
  position: absolute; inset: 0;
  background: linear-gradient(100deg, rgba(6,16,31,0.94) 0%, rgba(10,26,48,0.86) 46%, rgba(10,26,48,0.58) 100%);
}
.cs-hero > .wrap { position: relative; padding-top: 60px; padding-bottom: 60px; }
.cs-hero .eyebrow { color: var(--green-300); }
.cs-hero h1 { color: #fff; margin-bottom: 0.35em; }
.cs-hero .lead { color: #c6d3e4; }
.cs-hero .stats { margin-top: 26px; }
.cs-hero .stat {
  background: rgba(255,255,255,0.07);
  border-color: rgba(255,255,255,0.16);
  backdrop-filter: blur(3px);
}
.cs-hero .stat .label { color: #a9bad2; }
.cs-hero .stat .value { color: #fff; }
.cs-hero .stat .value .unit { color: #c6d3e4; }
.cs-hero .stat .context { color: #93a6c0; }
.cs-hero .stat.accent .value { color: var(--green-300); }
.cs-hero .photo-credit {
  position: relative; margin: 18px 0 0; font-size: 0.8rem; color: #8fa2bb;
}

/* photo-backed cards on the case studies index */
.card.has-photo { padding: 0; overflow: hidden; display: flex; flex-direction: column; }
.card.has-photo .thumb {
  display: block; height: 150px; background-size: cover; background-position: center;
  background-color: var(--navy-700);
}
.card.has-photo .card-body { padding: 18px 20px 20px; }
.card.has-photo .card-body > :first-child { margin-top: 0; }

@media (max-width: 720px) {
  .cs-hero > .wrap { padding-top: 40px; padding-bottom: 40px; }
  .cs-hero::before { background: linear-gradient(180deg, rgba(6,16,31,0.92) 0%, rgba(10,26,48,0.88) 100%); }
}