/* ========================================
   Sheffield Renewable Energy — Stylesheet
   Clean, premium, conversion-focused
   ======================================== */

:root {
  --green: #16A34A;
  --green-dark: #15803D;
  --green-light: #F0FDF4;
  --navy: #0F172A;
  --navy-light: #1E293B;
  --white: #FFFFFF;
  --off-white: #FAFAFA;
  --gray-50: #F9FAFB;
  --gray-100: #F3F4F6;
  --gray-200: #E5E7EB;
  --gray-400: #9CA3AF;
  --gray-600: #4B5563;
  --gray-700: #374151;
  --gray-800: #1F2937;
  --text: #111827;

  --font: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --radius: 8px;
  --radius-lg: 12px;
  --max-w: 1100px;
  --pad: 1.25rem;
}

*, *::before, *::after { margin:0; padding:0; box-sizing:border-box; }

html { scroll-behavior:smooth; scroll-padding-top:80px; }

body {
  font-family: var(--font);
  font-size: 1rem;
  line-height: 1.6;
  color: var(--text);
  background: var(--white);
  -webkit-font-smoothing: antialiased;
}

img { max-width:100%; height:auto; display:block; }
a { color: var(--green); text-decoration:none; }
a:hover { color: var(--green-dark); }
ul { list-style:none; }

.container { max-width:var(--max-w); margin:0 auto; padding:0 var(--pad); width:100%; }

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.75rem 1.75rem;
  font-size: 0.95rem;
  font-weight: 600;
  border: none;
  border-radius: var(--radius);
  background: var(--green);
  color: var(--white);
  cursor: pointer;
  transition: background 0.2s, transform 0.15s;
  font-family: var(--font);
  text-decoration: none;
}
.btn:hover { background: var(--green-dark); color: var(--white); transform: translateY(-1px); }
.btn-block { width:100%; }

/* ========================================
   HEADER
   ======================================== */
.header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255,255,255,0.95);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--gray-200);
  padding: 0.75rem 0;
}
.header .container {
  display: flex;
  justify-content: space-between;
  align-items: center;
}
.logo {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--navy);
  text-decoration: none;
  letter-spacing: -0.02em;
}
.logo:hover { color: var(--navy); }

.nav-list { display:flex; gap:1.5rem; align-items:center; }
.nav-list a {
  color: var(--gray-700);
  font-size: 0.9rem;
  font-weight: 500;
  transition: color 0.15s;
}
.nav-list a:hover { color: var(--green); }
.nav-cta {
  background: var(--green);
  color: var(--white) !important;
  padding: 0.5rem 1rem;
  border-radius: var(--radius);
}
.nav-cta:hover { background: var(--green-dark); }
.nav-toggle { display:none; background:none; border:none; cursor:pointer; padding:0.5rem; }
.nav-toggle span,
.nav-toggle span::before,
.nav-toggle span::after {
  display:block; width:22px; height:2px; background:var(--navy); border-radius:2px; transition:0.3s;
}
.nav-toggle span { position:relative; }
.nav-toggle span::before, .nav-toggle span::after { content:''; position:absolute; left:0; }
.nav-toggle span::before { top:-7px; }
.nav-toggle span::after { top:7px; }

/* ========================================
   HERO
   ======================================== */
.hero {
  background: var(--navy);
  color: var(--white);
  padding: 4rem 0;
}
.hero .container {
  display: grid;
  grid-template-columns: 1.1fr 1fr;
  gap: 3rem;
  align-items: center;
}
.hero-content h1 {
  font-size: 2.5rem;
  font-weight: 800;
  line-height: 1.15;
  margin-bottom: 1rem;
  letter-spacing: -0.03em;
}
.hero-content h1 strong { color: #4ADE80; }
.hero-content p {
  font-size: 1.1rem;
  color: #CBD5E1;
  line-height: 1.6;
  margin-bottom: 1.25rem;
  max-width: 540px;
}
.hero-bullets {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  margin-bottom: 2rem;
}
.hero-bullets li {
  color: #94A3B8;
  font-size: 0.95rem;
  padding-left: 1.25rem;
  position: relative;
}
.hero-bullets li::before {
  content: '\25CF';
  color: #4ADE80;
  position: absolute;
  left: 0;
  font-size: 0.7rem;
  top: 0.35rem;
}
.hero-image img {
  width: 100%;
  border-radius: var(--radius-lg);
  box-shadow: 0 4px 24px rgba(0,0,0,0.3);
  aspect-ratio: 4/3;
  object-fit: cover;
}

/* ========================================
   SERVICES
   ======================================== */
.services {
  padding: 5rem 0;
  background: var(--off-white);
}
.services h2 {
  text-align: center;
  font-size: 2rem;
  font-weight: 700;
  margin-bottom: 2.5rem;
  letter-spacing: -0.02em;
}
.services-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.5rem;
}
.service-card {
  background: var(--white);
  padding: 1.75rem;
  border-radius: var(--radius-lg);
  border: 1px solid var(--gray-200);
  transition: box-shadow 0.2s, transform 0.2s;
}
.service-card:hover {
  box-shadow: 0 4px 16px rgba(0,0,0,0.06);
  transform: translateY(-2px);
}
.service-card h3 {
  font-size: 1.05rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
  color: var(--navy);
}
.service-card p {
  color: var(--gray-600);
  font-size: 0.9rem;
  line-height: 1.55;
}

/* ========================================
   WHY US
   ======================================== */
.why-us {
  padding: 5rem 0;
}
.why-us h2 {
  text-align: center;
  font-size: 2rem;
  font-weight: 700;
  margin-bottom: 2.5rem;
  letter-spacing: -0.02em;
}
.why-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.25rem;
  max-width: 800px;
  margin: 0 auto;
}
.why-item {
  display: flex;
  align-items: flex-start;
  gap: 0.85rem;
  padding: 1rem;
}
.why-icon {
  flex-shrink: 0;
  width: 28px;
  height: 28px;
  border-radius: 50%;
  background: var(--green-light);
  color: var(--green);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 0.85rem;
}
.why-item strong {
  display: block;
  font-size: 0.95rem;
  margin-bottom: 0.15rem;
  color: var(--navy);
}
.why-item p {
  color: var(--gray-600);
  font-size: 0.85rem;
  line-height: 1.5;
}

/* ========================================
   COMMERCIAL
   ======================================== */
.commercial {
  padding: 5rem 0;
  background: var(--navy);
  color: var(--white);
}
.commercial-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 3rem;
  align-items: center;
}
.commercial-content h2 {
  font-size: 2rem;
  font-weight: 700;
  margin-bottom: 1rem;
  letter-spacing: -0.02em;
}
.commercial-content p {
  color: #CBD5E1;
  margin-bottom: 1.25rem;
  line-height: 1.6;
}
.commercial-content ul {
  display: flex;
  flex-direction: column;
  gap: 0.6rem;
  margin-bottom: 1.75rem;
}
.commercial-content ul li {
  color: #94A3B8;
  font-size: 0.9rem;
  padding-left: 1.25rem;
  position: relative;
}
.commercial-content ul li::before {
  content: '\25CF';
  color: #4ADE80;
  position: absolute;
  left: 0;
  font-size: 0.6rem;
  top: 0.4rem;
}
.commercial-content .btn { background: var(--white); color: var(--navy); }
.commercial-content .btn:hover { background: #E2E8F0; }
.commercial-image img {
  width: 100%;
  border-radius: var(--radius-lg);
  aspect-ratio: 4/3;
  object-fit: cover;
}

/* ========================================
   AREAS
   ======================================== */
.areas {
  padding: 4rem 0;
  background: var(--off-white);
}
.areas h2 {
  text-align: center;
  font-size: 2rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
  letter-spacing: -0.02em;
}
.areas-sub {
  text-align: center;
  color: var(--gray-600);
  margin-bottom: 1.75rem;
  font-size: 0.95rem;
}
.areas-grid {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 0.6rem;
}
.areas-grid span {
  background: var(--white);
  padding: 0.45rem 1rem;
  border-radius: 20px;
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--gray-700);
  border: 1px solid var(--gray-200);
}

/* ========================================
   CONTACT
   ======================================== */
.contact {
  padding: 5rem 0;
}
.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 3rem;
  align-items: start;
}
.contact-intro h2 {
  font-size: 2rem;
  font-weight: 700;
  margin-bottom: 1rem;
  letter-spacing: -0.02em;
}
.contact-intro > p {
  color: var(--gray-600);
  margin-bottom: 1.5rem;
  line-height: 1.6;
}
.contact-details {
  display: flex;
  flex-direction: column;
  gap: 0.85rem;
  margin-bottom: 2rem;
}
.contact-details p {
  font-size: 0.9rem;
  color: var(--gray-700);
}

/* FORM */
.form {
  background: var(--white);
  padding: 2rem;
  border-radius: var(--radius-lg);
  border: 1px solid var(--gray-200);
  box-shadow: 0 2px 12px rgba(0,0,0,0.04);
}
.form-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
  margin-bottom: 1rem;
}
.form-group {
  display: flex;
  flex-direction: column;
  gap: 0.3rem;
  margin-bottom: 1rem;
}
.form-group label {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--gray-700);
}
.req { color: #EF4444; }
.form-group input,
.form-group select,
.form-group textarea {
  padding: 0.6rem 0.75rem;
  border: 1.5px solid var(--gray-200);
  border-radius: var(--radius);
  font-size: 0.9rem;
  font-family: var(--font);
  transition: border-color 0.15s, box-shadow 0.15s;
  background: var(--white);
  color: var(--text);
  width: 100%;
}
.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
  outline: none;
  border-color: var(--green);
  box-shadow: 0 0 0 3px rgba(22,163,74,0.12);
}
.form-group textarea { resize: vertical; min-height: 80px; }
.form-group input::placeholder,
.form-group textarea::placeholder { color: var(--gray-400); }
.check-label {
  display: flex;
  align-items: flex-start;
  gap: 0.5rem;
  font-size: 0.8rem;
  color: var(--gray-600);
  cursor: pointer;
}
.check-label input { width: auto; margin-top: 2px; flex-shrink:0; accent-color: var(--green); }
.form-consent { margin-bottom: 0; }

.form-msg {
  padding: 0.85rem;
  border-radius: var(--radius);
  font-size: 0.85rem;
  font-weight: 500;
  margin-top: 1rem;
}
.form-msg-success { background: var(--green-light); color: var(--green-dark); border: 1px solid #BBF7D0; }
.form-msg-error { background: #FEF2F2; color: #991B1B; border: 1px solid #FECACA; }

/* ========================================
   FOOTER
   ======================================== */
.footer {
  background: var(--navy);
  color: #94A3B8;
  padding: 3rem 0 1.5rem;
}
.footer-grid {
  display: grid;
  grid-template-columns: 1.5fr 1fr 1fr;
  gap: 2rem;
  margin-bottom: 2rem;
}
.footer-brand { font-weight: 700; color: var(--white); font-size: 1rem; margin-bottom:0.35rem; }
.footer-grid h4 {
  color: var(--white);
  font-size: 0.85rem;
  font-weight: 600;
  margin-bottom: 0.65rem;
}
.footer-grid ul { display:flex; flex-direction:column; gap:0.4rem; }
.footer-grid ul li { font-size: 0.85rem; }
.footer-grid a { color: #94A3B8; transition: color 0.15s; }
.footer-grid a:hover { color: var(--white); }
.footer-bottom { border-top: 1px solid rgba(255,255,255,0.08); padding-top:1.25rem; text-align:center; font-size:0.8rem; }

/* ========================================
   RESPONSIVE
   ======================================== */
@media (max-width: 900px) {
  .hero .container,
  .commercial-grid,
  .contact-grid { grid-template-columns: 1fr; }

  .hero-content h1 { font-size: 2rem; }
  .services-grid { grid-template-columns: 1fr 1fr; }
  .why-grid { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr 1fr; }

  .hero-image { order: -1; }
  .hero-image img { max-width: 100%; }
}

@media (max-width: 640px) {
  .nav-list {
    position: fixed;
    top: 0;
    right: -100%;
    width: 260px;
    height: 100vh;
    background: var(--white);
    flex-direction: column;
    padding: 5rem 1.5rem 2rem;
    box-shadow: 0 0 40px rgba(0,0,0,0.15);
    transition: right 0.3s;
    gap: 1rem;
    z-index: 99;
  }
  .nav-list.active { right: 0; }
  .nav-toggle { display: block; position: relative; z-index: 100; }

  .services-grid { grid-template-columns: 1fr; }
  .form-row { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr; }

  .hero { padding: 2.5rem 0; }
  .hero-content h1 { font-size: 1.75rem; }
  .contact { padding: 3rem 0; }
  .services, .why-us, .commercial { padding: 3rem 0; }
}

/* ========================================
   SEQUENTIAL SECTIONS FOR SEO EXPANSION PAGES
   These IDs exist to allow internal linking:
   /solar-panels-sheffield
   /battery-storage-sheffield
   /ev-charging-sheffield
   /commercial-energy-sheffield
   /solar-battery-installation-sheffield
   /industrial-energy-sheffield
   ======================================== */

@media print {
  .header, .footer, .btn, form, .nav-toggle { display:none !important; }
  body { font-size: 12pt; }
}