:root {
  --bg: #f4f7f4;
  --surface: #ffffff;
  --surface-soft: #edf3ef;
  --ink: #0d1714;
  --muted: #61706b;
  --line: #d9e4dd;
  --green: #21855f;
  --green-strong: #0f5b44;
  --lime: #b9ea5a;
  --aqua: #c9f1e5;
  --amber: #f6c25f;
  --dark: #0f1e1a;
  --shadow: 0 28px 80px rgba(13, 23, 20, 0.16);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  overflow-x: hidden;
  background: var(--bg);
  color: var(--ink);
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  line-height: 1.5;
}

body.nav-open {
  overflow: hidden;
}

a {
  color: inherit;
  text-decoration: none;
}

button {
  font: inherit;
}

.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 20;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  padding: 16px clamp(18px, 4vw, 62px);
  border-bottom: 1px solid rgba(255, 255, 255, 0.14);
  background: rgba(13, 23, 20, 0.8);
  color: #ffffff;
  backdrop-filter: blur(18px);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  min-width: max-content;
}

.brand-logo {
  width: 46px;
  height: 46px;
  object-fit: contain;
  border-radius: 8px;
  background: #ffffff;
}

.brand strong,
.brand small {
  display: block;
}

.brand small {
  color: rgba(255, 255, 255, 0.66);
  font-size: 0.74rem;
  font-weight: 700;
  text-transform: uppercase;
}

.main-nav {
  display: flex;
  align-items: center;
  gap: 6px;
  color: rgba(255, 255, 255, 0.78);
  font-size: 0.95rem;
}

.main-nav a {
  min-height: 42px;
  display: inline-flex;
  align-items: center;
  padding: 9px 12px;
  border-radius: 8px;
  transition: background 180ms ease, color 180ms ease, transform 180ms ease;
}

.main-nav a:hover,
.main-nav a.active {
  background: rgba(255, 255, 255, 0.1);
  color: #ffffff;
}

.main-nav a:hover {
  transform: translateY(-1px);
}

.main-nav .nav-cta {
  background: var(--lime);
  color: var(--ink);
  font-weight: 850;
}

.menu-toggle {
  display: none;
  width: 46px;
  height: 46px;
  align-items: center;
  justify-content: center;
  flex-direction: column;
  gap: 6px;
  border: 1px solid rgba(255, 255, 255, 0.2);
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.08);
  color: #ffffff;
  cursor: pointer;
}

.menu-toggle span {
  width: 20px;
  height: 2px;
  background: currentColor;
  transition: transform 180ms ease;
}

.menu-toggle[aria-expanded="true"] span:first-child {
  transform: translateY(4px) rotate(45deg);
}

.menu-toggle[aria-expanded="true"] span:last-child {
  transform: translateY(-4px) rotate(-45deg);
}

.section-dark {
  background: var(--dark);
  color: #ffffff;
}

.hero {
  position: relative;
  display: grid;
  grid-template-columns: minmax(0, 0.92fr) minmax(360px, 1.08fr);
  gap: clamp(36px, 6vw, 88px);
  align-items: center;
  min-height: 100svh;
  padding: clamp(126px, 15vh, 170px) clamp(20px, 6vw, 92px) clamp(56px, 7vw, 96px);
  overflow: hidden;
}

.hero::before {
  position: absolute;
  inset: 0;
  background:
    radial-gradient(circle at 82% 18%, rgba(185, 234, 90, 0.28), transparent 26%),
    radial-gradient(circle at 20% 80%, rgba(201, 241, 229, 0.2), transparent 30%),
    linear-gradient(135deg, rgba(33, 133, 95, 0.32), transparent 48%);
  content: "";
}

.hero > * {
  position: relative;
}

.eyebrow,
.section-kicker {
  margin: 0 0 14px;
  color: var(--green-strong);
  font-size: 0.78rem;
  font-weight: 850;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

.section-dark .eyebrow,
.section-dark .section-kicker {
  color: var(--lime);
}

h1,
h2,
h3,
p {
  margin-top: 0;
}

h1 {
  max-width: 780px;
  margin-bottom: 24px;
  font-size: clamp(3rem, 6.8vw, 6rem);
  line-height: 0.96;
  letter-spacing: 0;
}

h2 {
  margin-bottom: 18px;
  font-size: clamp(2rem, 4.3vw, 4.35rem);
  line-height: 1.04;
  letter-spacing: 0;
}

h3 {
  margin-bottom: 12px;
  font-size: 1.18rem;
}

.lead {
  max-width: 680px;
  color: rgba(255, 255, 255, 0.74);
  font-size: clamp(1.08rem, 2vw, 1.34rem);
}

.price-panel {
  display: inline-grid;
  gap: 2px;
  margin: 8px 0 24px;
  padding: 16px 18px;
  border: 1px solid rgba(255, 255, 255, 0.14);
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.08);
}

.price-panel span,
.price-panel small {
  color: rgba(255, 255, 255, 0.72);
  font-weight: 750;
}

.price-panel span {
  font-size: 0.78rem;
  text-transform: uppercase;
}

.price-panel strong {
  color: var(--lime);
  font-size: clamp(1.9rem, 4vw, 3rem);
  line-height: 1;
}

.hero-actions,
.contact-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  align-items: center;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 50px;
  padding: 12px 18px;
  border: 1px solid transparent;
  border-radius: 8px;
  font-weight: 850;
  transition: transform 180ms ease, box-shadow 180ms ease, background 180ms ease;
}

.button:hover {
  transform: translateY(-2px);
}

.button.primary {
  background: var(--green);
  color: #ffffff;
  box-shadow: 0 16px 36px rgba(33, 133, 95, 0.28);
}

.button.secondary {
  border-color: var(--line);
  background: #ffffff;
}

.button.ghost {
  border-color: rgba(255, 255, 255, 0.2);
  background: rgba(255, 255, 255, 0.08);
  color: #ffffff;
}

.hero-stage {
  position: relative;
  min-height: 560px;
}

.product-card {
  position: absolute;
  inset: 28px 8% 54px;
  display: grid;
  place-items: center;
  overflow: hidden;
  border: 1px solid rgba(255, 255, 255, 0.16);
  border-radius: 8px;
  background:
    linear-gradient(145deg, rgba(255, 255, 255, 0.96), rgba(232, 239, 235, 0.9)),
    #ffffff;
  box-shadow: var(--shadow);
}

.product-card::before {
  position: absolute;
  top: 26px;
  left: 28px;
  color: var(--muted);
  content: "Kortenhoef Energy Storage";
  font-size: 0.78rem;
  font-weight: 850;
  text-transform: uppercase;
}

.product-card img {
  width: min(88%, 520px);
  max-height: 430px;
  object-fit: contain;
  filter: drop-shadow(0 28px 34px rgba(13, 23, 20, 0.18));
}

.metric-card {
  position: absolute;
  min-width: 188px;
  padding: 18px;
  border: 1px solid rgba(255, 255, 255, 0.18);
  border-radius: 8px;
  background: rgba(15, 30, 26, 0.9);
  color: #ffffff;
  box-shadow: 0 18px 52px rgba(0, 0, 0, 0.22);
}

.metric-card span {
  display: block;
  margin-bottom: 6px;
  color: var(--lime);
  font-size: 0.76rem;
  font-weight: 850;
  text-transform: uppercase;
}

.metric-card strong {
  font-size: 1.35rem;
}

.metric-capacity {
  right: 0;
  top: 86px;
}

.metric-cycles {
  left: 0;
  bottom: 40px;
}

.proof-strip {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1px;
  background: var(--line);
  border-bottom: 1px solid var(--line);
}

.proof-strip div {
  min-height: 148px;
  padding: clamp(22px, 4vw, 34px);
  background: var(--surface);
}

.proof-strip span {
  display: block;
  margin-bottom: 10px;
  color: var(--green-strong);
  font-size: 0.8rem;
  font-weight: 850;
  text-transform: uppercase;
}

.proof-strip strong {
  font-size: clamp(1.05rem, 2vw, 1.35rem);
}

.about-section,
.seo-intro,
.battery-section,
.compatibility-section,
.testing-section,
.safety-section,
.specs-section,
.reviews-section,
.faq-section,
.contact-section {
  padding: clamp(62px, 9vw, 118px) clamp(20px, 6vw, 92px);
}

.section-heading {
  max-width: 920px;
  margin-bottom: clamp(34px, 6vw, 64px);
}

.about-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 18px;
}

.about-grid article,
.feature-item,
.assurance-card {
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--surface);
}

.about-grid article {
  min-height: 300px;
  padding: clamp(24px, 4vw, 38px);
}

.about-grid p,
.battery-copy p,
.seo-copy p,
.compatibility-copy p,
.feature-item p,
.assurance-card p {
  color: var(--muted);
}

.seo-intro {
  display: grid;
  grid-template-columns: minmax(280px, 0.9fr) minmax(300px, 1.1fr);
  gap: clamp(34px, 8vw, 96px);
  background: var(--surface);
}

.seo-copy {
  display: grid;
  gap: 16px;
  align-content: start;
}

.seo-copy p {
  margin-bottom: 0;
  font-size: 1.05rem;
}

.battery-section {
  display: grid;
  grid-template-columns: minmax(280px, 0.9fr) minmax(300px, 1.1fr);
  gap: clamp(34px, 8vw, 96px);
  background: var(--surface-soft);
}

.feature-list {
  display: grid;
  gap: 14px;
}

.feature-item {
  display: grid;
  grid-template-columns: 54px minmax(0, 1fr);
  gap: 8px 18px;
  align-items: start;
  padding: 22px;
}

.feature-item span {
  grid-row: span 2;
  display: grid;
  width: 44px;
  height: 44px;
  place-items: center;
  border-radius: 8px;
  background: var(--dark);
  color: var(--lime);
  font-weight: 900;
}

.feature-item p {
  margin-bottom: 0;
}

.compatibility-section {
  background: var(--bg);
}

.compatibility-layout {
  display: grid;
  grid-template-columns: minmax(280px, 0.74fr) minmax(320px, 1.26fr);
  gap: clamp(28px, 6vw, 72px);
  align-items: start;
}

.brand-cloud {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.brand-cloud span {
  display: inline-flex;
  min-height: 42px;
  align-items: center;
  padding: 9px 13px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--surface);
  color: var(--ink);
  font-weight: 850;
  box-shadow: 0 10px 28px rgba(13, 23, 20, 0.05);
}

.testing-section {
  background: var(--surface);
}

.process-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 18px;
}

.process-card {
  min-height: 280px;
  padding: clamp(24px, 4vw, 38px);
  border: 1px solid var(--line);
  border-radius: 8px;
  background: linear-gradient(180deg, #ffffff, #f7faf8);
}

.process-card span {
  display: inline-flex;
  min-height: 36px;
  align-items: center;
  padding: 6px 10px;
  margin-bottom: 30px;
  border-radius: 8px;
  background: var(--surface-soft);
  color: var(--green-strong);
  font-size: 0.8rem;
  font-weight: 900;
  text-transform: uppercase;
}

.process-card p {
  color: var(--muted);
}

.safety-section {
  position: relative;
  overflow: hidden;
}

.safety-section::before {
  position: absolute;
  inset: 0;
  background:
    radial-gradient(circle at 12% 20%, rgba(185, 234, 90, 0.18), transparent 24%),
    radial-gradient(circle at 90% 78%, rgba(246, 194, 95, 0.18), transparent 24%);
  content: "";
}

.safety-section > * {
  position: relative;
}

.assurance-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 18px;
}

.assurance-card {
  min-height: 270px;
  padding: clamp(24px, 4vw, 38px);
  border-color: rgba(255, 255, 255, 0.15);
  background: rgba(255, 255, 255, 0.06);
}

.assurance-card span {
  display: inline-flex;
  min-height: 38px;
  align-items: center;
  padding: 7px 10px;
  margin-bottom: 28px;
  border-radius: 8px;
  background: var(--lime);
  color: var(--ink);
  font-weight: 900;
}

.assurance-card p {
  color: rgba(255, 255, 255, 0.72);
}

.specs-section {
  background: var(--surface);
}

.spec-list {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  margin: 0;
  border-top: 1px solid var(--line);
  border-left: 1px solid var(--line);
}

.spec-list.detailed {
  grid-template-columns: repeat(5, 1fr);
}

.spec-list div {
  min-height: 136px;
  padding: 22px;
  border-right: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.spec-list dt {
  margin-bottom: 18px;
  color: var(--muted);
  font-size: 0.78rem;
  font-weight: 850;
  text-transform: uppercase;
}

.spec-list dd {
  margin: 0;
  font-size: 1.15rem;
  font-weight: 850;
}

.reviews-section {
  background: var(--surface-soft);
}

.review-grid,
.faq-grid,
.news-list {
  display: grid;
  gap: 18px;
}

.review-grid {
  grid-template-columns: repeat(3, 1fr);
}

.review-card,
.faq-grid details,
.news-card {
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--surface);
}

.review-card {
  min-height: 220px;
  padding: clamp(24px, 4vw, 34px);
}

.review-card span {
  display: inline-flex;
  margin-bottom: 26px;
  color: var(--green-strong);
  font-size: 0.8rem;
  font-weight: 900;
  text-transform: uppercase;
}

.review-card p,
.review-note,
.faq-grid p,
.news-card p {
  color: var(--muted);
}

.review-note {
  max-width: 760px;
  margin: 26px 0 0;
}

.faq-section {
  background: var(--surface);
}

.faq-grid {
  grid-template-columns: repeat(2, 1fr);
}

.faq-grid details {
  padding: 22px;
}

.faq-grid summary {
  cursor: pointer;
  color: var(--ink);
  font-weight: 900;
}

.faq-grid p {
  margin: 14px 0 0;
}

.news-hero {
  padding: clamp(126px, 15vh, 170px) clamp(20px, 6vw, 92px) clamp(56px, 7vw, 96px);
}

.news-list {
  padding: clamp(62px, 9vw, 118px) clamp(20px, 6vw, 92px);
  background: var(--bg);
}

.news-card {
  display: grid;
  grid-template-columns: minmax(220px, 0.34fr) minmax(0, 1fr);
  gap: clamp(20px, 4vw, 38px);
  align-items: center;
  padding: clamp(24px, 4vw, 40px);
}

.news-card img {
  width: 100%;
  aspect-ratio: 16 / 10;
  object-fit: cover;
  border-radius: 8px;
  background: var(--surface-soft);
}

.news-card h2 {
  max-width: 980px;
  font-size: clamp(1.75rem, 3.4vw, 3rem);
}

.news-card p {
  max-width: 920px;
  font-size: 1.05rem;
}

.news-card a {
  display: inline-flex;
  margin-top: 8px;
  color: var(--green-strong);
  font-weight: 900;
}

.article-hero {
  padding: clamp(126px, 15vh, 170px) clamp(20px, 6vw, 92px) clamp(56px, 7vw, 96px);
}

.article-hero h1 {
  max-width: 1040px;
}

.article-layout {
  display: grid;
  grid-template-columns: minmax(280px, 0.72fr) minmax(320px, 1fr);
  gap: clamp(30px, 7vw, 82px);
  padding: clamp(62px, 9vw, 118px) clamp(20px, 6vw, 92px);
  background: var(--surface);
}

.article-image {
  position: sticky;
  top: 108px;
  align-self: start;
  margin: 0;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--surface-soft);
  box-shadow: var(--shadow);
}

.article-image img {
  display: block;
  width: 100%;
  aspect-ratio: 4 / 3;
  object-fit: cover;
}

.article-content {
  max-width: 820px;
}

.article-content p {
  color: var(--muted);
  font-size: clamp(1.06rem, 1.5vw, 1.18rem);
}

.source-link {
  padding-top: 18px;
  border-top: 1px solid var(--line);
  font-weight: 850;
}

.source-link a {
  color: var(--green-strong);
}

.contact-section {
  display: grid;
  grid-template-columns: minmax(260px, 0.64fr) minmax(300px, 0.72fr) minmax(320px, 1fr);
  gap: clamp(30px, 7vw, 82px);
  align-items: stretch;
  background: var(--bg);
}

address {
  margin-bottom: 24px;
  color: var(--muted);
  font-style: normal;
  font-size: 1.08rem;
}

.location-panel {
  min-height: 470px;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--surface);
  box-shadow: var(--shadow);
}

.location-panel iframe {
  display: block;
  width: 100%;
  height: 100%;
  min-height: 470px;
  border: 0;
}

.contact-form {
  display: grid;
  align-content: start;
  gap: 14px;
  padding: clamp(22px, 4vw, 34px);
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--surface);
  box-shadow: 0 18px 50px rgba(13, 23, 20, 0.08);
}

.contact-form h3 {
  margin-bottom: 4px;
}

.contact-form label {
  display: grid;
  gap: 7px;
  color: var(--muted);
  font-size: 0.85rem;
  font-weight: 850;
  text-transform: uppercase;
}

.contact-form input,
.contact-form textarea {
  width: 100%;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #ffffff;
  color: var(--ink);
  font: inherit;
  padding: 12px 13px;
  text-transform: none;
}

.contact-form input:focus,
.contact-form textarea:focus {
  outline: 3px solid rgba(33, 133, 95, 0.16);
  border-color: var(--green);
}

.contact-form textarea {
  resize: vertical;
}

.contact-form .button {
  width: 100%;
  cursor: pointer;
}

.hidden-field {
  position: absolute;
  left: -9999px;
}

.form-message {
  margin: 0;
  padding: 12px 14px;
  border-radius: 8px;
  font-size: 0.95rem;
  font-weight: 750;
}

.form-message.success {
  background: #e8f7ed;
  color: #17633d;
}

.form-message.error {
  background: #fff0e4;
  color: #93520c;
}

.site-footer {
  display: flex;
  justify-content: space-between;
  gap: 20px;
  padding: 28px clamp(20px, 6vw, 92px);
  background: var(--dark);
  color: rgba(255, 255, 255, 0.72);
}

.site-footer span {
  color: #ffffff;
  font-weight: 850;
}

.reveal {
  opacity: 0;
  transform: translateY(22px);
  transition: opacity 520ms ease, transform 520ms ease;
}

.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}

@media (max-width: 1060px) {
  .hero,
  .seo-intro,
  .battery-section,
  .compatibility-layout,
  .news-card,
  .article-layout,
  .contact-section {
    grid-template-columns: 1fr;
  }

  .article-image {
    position: static;
  }

  .hero-stage {
    min-height: 500px;
  }

  .proof-strip,
  .about-grid,
  .assurance-grid,
  .process-grid,
  .review-grid,
  .faq-grid,
  .spec-list {
    grid-template-columns: repeat(2, 1fr);
  }

  .spec-list.detailed {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 760px) {
  .site-header {
    padding: 14px 18px;
  }

  .menu-toggle {
    display: inline-flex;
  }

  .main-nav {
    position: fixed;
    top: 75px;
    left: 12px;
    right: 12px;
    display: none;
    flex-direction: column;
    align-items: stretch;
    padding: 12px;
    border: 1px solid rgba(255, 255, 255, 0.16);
    border-radius: 8px;
    background: rgba(13, 23, 20, 0.96);
    box-shadow: var(--shadow);
  }

  body.nav-open .main-nav {
    display: flex;
  }

  .main-nav a {
    justify-content: center;
  }

  .hero {
    min-height: auto;
    padding-top: 118px;
  }

  h1 {
    font-size: clamp(2.55rem, 12vw, 3.5rem);
    line-height: 1.02;
  }

  h2 {
    font-size: clamp(2rem, 10vw, 3rem);
  }

  .hero-actions,
  .contact-actions,
  .site-footer {
    align-items: stretch;
    flex-direction: column;
  }

  .button {
    width: 100%;
  }

  .hero-stage {
    min-height: 430px;
  }

  .product-card {
    inset: 16px 0 54px;
  }

  .metric-card {
    min-width: 160px;
  }

  .metric-capacity {
    right: 8px;
    top: 24px;
  }

  .metric-cycles {
    left: 8px;
    bottom: 22px;
  }

  .proof-strip,
  .about-grid,
  .assurance-grid,
  .process-grid,
  .review-grid,
  .faq-grid,
  .spec-list {
    grid-template-columns: 1fr;
  }

  .spec-list.detailed {
    grid-template-columns: 1fr;
  }

  .feature-item {
    grid-template-columns: 1fr;
  }

  .feature-item span {
    grid-row: auto;
  }

  .location-panel,
  .location-panel iframe {
    min-height: 360px;
  }
}

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

  *,
  *::before,
  *::after {
    transition: none !important;
  }

  .reveal {
    opacity: 1;
    transform: none;
  }
}