/* Serck Separation Technologies – layout matching original site */
:root {
  --primary: #3952A4;
  --primary-hover: #1E73BE;
  --secondary: #D9BF32;
  --text: #555;
  --heading: #333;
  --nav: #666;
  --border: #e5e5e5;
  --max: 1080px;
}

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

html {
  scroll-behavior: smooth;
  background: var(--primary);
}

body {
  margin: 0;
  font-family: "Lato", Helvetica, Arial, sans-serif;
  font-weight: 400;
  font-size: 15px;
  line-height: 1.65;
  color: var(--text);
  background: #fff;
  min-height: 100vh;
  max-width: 1200px;
  margin-left: auto;
  margin-right: auto;
  box-shadow: 0 0 30px rgba(0, 0, 0, 0.25);
}

img {
  max-width: 100%;
  height: auto;
  border: 0;
  vertical-align: middle;
}

a {
  color: var(--primary);
  text-decoration: none;
}

a:hover {
  color: var(--primary-hover);
}

h1, h2, h3, h4, h5, h6 {
  font-family: "Lato", Helvetica, Arial, sans-serif;
  font-weight: 700;
  line-height: 1.3;
  color: var(--heading);
  margin: 0 0 0.65em;
}

p { margin: 0 0 1em; }

ul {
  margin: 0 0 1em;
  padding-left: 1.25em;
}

.container {
  width: 100%;
  max-width: var(--max);
  margin: 0 auto;
  padding: 0 20px;
}

.skip-link {
  position: absolute;
  left: -9999px;
}

.skip-link:focus {
  left: 8px;
  top: 8px;
  z-index: 9999;
  background: #fff;
  padding: 8px 12px;
}

.clearfix::after {
  content: "";
  display: table;
  clear: both;
}

/* ========== Header ========== */
.site-header {
  background: #fff;
  border-bottom: 1px solid var(--border);
  position: relative;
  z-index: 100;
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 100px;
  gap: 1rem;
}

.logo {
  flex-shrink: 0;
}

.logo img {
  display: block;
  max-height: 90px;
  width: auto;
}

.header-right {
  display: flex;
  align-items: center;
  gap: 0.25rem;
  position: relative;
}

.nav-main {
  display: flex;
  align-items: center;
  list-style: none;
  margin: 0;
  padding: 0;
  flex-wrap: wrap;
  justify-content: flex-end;
}

.nav-main a {
  display: block;
  padding: 0.4rem 0.55rem;
  font-weight: 700;
  font-size: 12px;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: var(--nav);
}

.nav-main a:hover {
  color: var(--primary);
}

.nav-main a.active {
  color: #222;
}

.search-toggle,
.menu-toggle {
  background: none;
  border: 0;
  border-left: 1px solid var(--border);
  cursor: pointer;
  padding: 0.45rem 0.65rem;
  color: #444;
  font-size: 1rem;
  line-height: 1;
  margin-left: 0.25rem;
}

.menu-toggle { display: none; }

.search-panel {
  display: none;
  position: absolute;
  right: 0;
  top: 100%;
  background: #fff;
  border: 1px solid var(--border);
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.12);
  padding: 10px;
  width: 280px;
  z-index: 50;
}

.search-panel.open { display: block; }

.search-panel form {
  display: flex;
}

.search-panel input {
  flex: 1;
  border: 1px solid #ccc;
  padding: 0.5rem 0.65rem;
  font: inherit;
}

.search-panel button {
  background: var(--secondary);
  border: 0;
  padding: 0 0.85rem;
  cursor: pointer;
  font-weight: 700;
}

/* ========== Homepage hero ========== */
.hero-home {
  position: relative;
  height: 300px;
  background: #1a2744 center / cover no-repeat;
  display: flex;
  align-items: center;
  justify-content: center;
}

.hero-home::before {
  content: "";
  position: absolute;
  inset: 0;
  background: rgba(0, 0, 0, 0.12);
}

.hero-home h1 {
  position: relative;
  z-index: 1;
  margin: 0;
  color: #fff;
  font-size: 2.75rem;
  font-weight: 700;
  text-shadow: 0 1px 4px rgba(0, 0, 0, 0.35);
}

/* Section title box (home) */
.section-title-wrap {
  position: relative;
  text-align: center;
  margin: 2rem 0 1.75rem;
  padding: 0 1rem;
}

.section-title-wrap::before {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  top: 50%;
  height: 1px;
  background: #ddd;
}

.section-title-box {
  position: relative;
  display: inline-block;
  background: #fff;
  border: 1px solid #ddd;
  padding: 0.55rem 1.25rem;
  font-size: 13px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: #555;
  max-width: 95%;
}

/* Home lead */
.home-lead {
  overflow: hidden;
  margin-bottom: 2.5rem;
}

.home-lead h1 {
  font-size: 1.85rem;
  color: var(--heading);
  margin-bottom: 0.85rem;
}

.home-lead .diagram {
  float: right;
  margin: 0 0 1rem 1.5rem;
  max-width: 170px;
}

.home-lead .source-item {
  list-style: disc;
  margin: 0 0 0.15rem 1.1em;
  padding: 0;
  font-weight: 700;
  color: var(--heading);
}

.home-lead .source-desc {
  margin: 0 0 1rem 1.75em;
  color: var(--text);
}

/* Four columns */
.home-cols {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1.5rem;
  padding-bottom: 2.5rem;
  border-top: 1px solid transparent;
}

.home-cols h3 {
  font-size: 1.05rem;
  color: #555;
  margin: 0 0 0.75rem;
  padding-top: 0.5rem;
}

.home-cols p {
  margin: 0;
  line-height: 1.9;
  color: #777;
  font-size: 14px;
}

.home-cols a {
  color: var(--primary);
}

/* ========== Inner page: banner + title + sidebar ========== */
.page-layout {
  display: grid;
  grid-template-columns: 1fr 220px;
  gap: 2.5rem;
  align-items: start;
  padding-top: 1.5rem;
  padding-bottom: 3rem;
}

.page-main {
  min-width: 0;
}

.page-banner-img {
  display: block;
  width: 100%;
  height: auto;
}

.page-title-bar {
  background: var(--primary);
  color: #fff;
  text-align: center;
  padding: 0.85rem 1rem;
  margin: 0 0 1.5rem;
}

.page-title-bar h1 {
  margin: 0;
  color: #fff;
  font-size: 1.5rem;
  font-weight: 700;
}

.page-body h2,
.page-body h3 {
  color: var(--primary);
  font-size: 1.35rem;
}

.page-body h2 a,
.page-body h3 a {
  color: var(--primary);
}

.product-section {
  margin-bottom: 2.25rem;
  overflow: hidden;
}

.product-section .float-img-right {
  float: right;
  margin: 0 0 1rem 1.25rem;
  max-width: 260px;
}

.product-section .float-img-left {
  float: left;
  margin: 0 1.25rem 1rem 0;
  max-width: 280px;
}

/* Sidebar – matches original: plain links + hairline dividers */
.side-nav {
  padding-top: 0;
  background: transparent;
  border: 0;
}

.side-nav ul {
  list-style: none;
  margin: 0;
  padding: 0;
}

.side-nav li {
  border-bottom: 1px solid #eee;
}

.side-nav a {
  display: block;
  padding: 0.7rem 0;
  color: var(--primary);
  font-size: 15px;
  font-weight: 400;
}

.side-nav a:hover,
.side-nav a.active {
  color: var(--primary-hover);
  font-weight: 700;
}

/* Detail pages without top banner image use simpler title */
.simple-title {
  padding: 1.5rem 0 0.5rem;
}

.simple-title h1 {
  color: var(--primary);
  font-size: 1.75rem;
}

/* Contact */
.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1.15fr;
  gap: 2.5rem;
  padding: 2rem 0 3rem;
}

.contact-info p {
  margin-bottom: 0.5rem;
}

.contact-form label {
  display: block;
  font-weight: 700;
  margin: 0.85rem 0 0.3rem;
  font-size: 0.92rem;
  color: var(--heading);
}

.contact-form input,
.contact-form textarea {
  width: 100%;
  padding: 0.55rem 0.7rem;
  border: 1px solid #ccc;
  font: inherit;
}

.contact-form textarea {
  min-height: 130px;
  resize: vertical;
}

.btn {
  display: inline-block;
  background: var(--primary);
  color: #fff !important;
  border: 0;
  padding: 0.65rem 1.35rem;
  font-weight: 700;
  cursor: pointer;
  margin-top: 1rem;
}

.btn:hover { background: var(--primary-hover); }

.form-message {
  display: none;
  margin-top: 1rem;
  padding: 0.75rem 1rem;
  background: #e8f5e9;
  border-left: 4px solid #2e7d32;
  color: #1b5e20;
}

.form-message.show { display: block; }

/* Footer */
.site-footer {
  background: var(--primary);
  color: #fff;
  padding: 1rem 0;
}

.site-footer a {
  color: #fff;
  text-decoration: underline;
}

.copyright { font-size: 0.9rem; }

/* Back to top */
.back-to-top {
  position: fixed;
  right: 20px;
  bottom: 20px;
  width: 42px;
  height: 42px;
  border-radius: 50%;
  border: 2px solid var(--primary);
  background: #fff;
  color: var(--primary);
  font-size: 1.1rem;
  cursor: pointer;
  opacity: 0;
  visibility: hidden;
  transition: 0.25s;
  z-index: 900;
  display: flex;
  align-items: center;
  justify-content: center;
  text-decoration: none;
}

.back-to-top.visible {
  opacity: 1;
  visibility: visible;
}

.back-to-top:hover {
  background: var(--primary);
  color: #fff;
}

/* Mobile */
.mobile-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.45);
  opacity: 0;
  visibility: hidden;
  transition: 0.25s;
  z-index: 1100;
}

.mobile-overlay.open {
  opacity: 1;
  visibility: visible;
}

.mobile-drawer {
  position: fixed;
  top: 0;
  left: 0;
  width: min(300px, 86vw);
  height: 100%;
  background: #fff;
  transform: translateX(-105%);
  transition: transform 0.3s ease;
  z-index: 1200;
  padding: 1.25rem;
  overflow-y: auto;
}

.mobile-drawer.open { transform: translateX(0); }

.mobile-drawer .close-drawer {
  background: none;
  border: 0;
  font-size: 1.5rem;
  cursor: pointer;
  float: right;
}

.mobile-nav {
  list-style: none;
  padding: 2rem 0 0;
  margin: 0;
  clear: both;
}

.mobile-nav a {
  display: block;
  padding: 0.85rem 0;
  border-bottom: 1px solid var(--border);
  font-weight: 700;
  text-transform: uppercase;
  color: #111;
}

@media (max-width: 980px) {
  .nav-main { display: none; }
  .menu-toggle { display: inline-flex; }
  .header-inner { min-height: 72px; }
  .logo img { max-height: 64px; }
  .home-cols { grid-template-columns: repeat(2, 1fr); }
  .page-layout {
    grid-template-columns: 1fr;
  }
  .side-nav {
    order: -1;
    border: 1px solid var(--border);
    padding: 0 1rem;
    margin-bottom: 0.5rem;
  }
  .contact-grid { grid-template-columns: 1fr; }
  .hero-home { height: 220px; }
  .hero-home h1 { font-size: 2rem; }
}

@media (max-width: 600px) {
  .home-cols { grid-template-columns: 1fr; }
  .home-lead .diagram,
  .product-section .float-img-right,
  .product-section .float-img-left {
    float: none;
    display: block;
    margin: 0 auto 1rem;
    max-width: 220px;
  }
  body { box-shadow: none; }
}