/* ===================================================================
   Advantage Filter MFG - Commercial Site
   Design System v5: Industrial strength, clear hierarchy
   =================================================================== */

/* --- Reset & Tokens ------------------------------------------------ */
:root {
  --c-brand: #2a7c9f;
  --c-brand-hover: #238ab4;
  --c-brand-light: #e3f2f7;
  --c-brand-dark: #1d5872;
  --c-dark: #0f1419;
  --c-dark-2: #1a2129;
  --c-ink: #0d1117;
  --c-body: #374151;
  --c-muted: #6b7280;
  --c-border: #e5e7eb;
  --c-bg: #ffffff;
  --c-surface: #f8fafc;
  --c-orange: #d97706;
  --c-orange-light: #fef3c7;
  --font-display: "Poppins", system-ui, -apple-system, sans-serif;
  --font-body: "Inter", system-ui, -apple-system, sans-serif;
  --max-w: 1180px;
  --radius: 6px;
  --radius-lg: 12px;
  --shadow-sm: 0 1px 2px rgba(0,0,0,.05);
  --shadow-md: 0 4px 12px rgba(0,0,0,.08);
  --shadow-lg: 0 10px 40px rgba(0,0,0,.12);
  --transition: .18s ease;
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; -webkit-font-smoothing: antialiased; }
body {
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.6;
  color: var(--c-ink);
  background: var(--c-bg);
}
img { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; }
ul, ol { list-style: none; }

.wrap {
  width: 100%;
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 32px;
}

/* --- Skip Link ----------------------------------------------------- */
.skip { position: absolute; left: -9999px; top: 8px; background: #fff; padding: 8px 12px; border-radius: 6px; z-index: 100; font-size: 14px; border: 1px solid var(--c-border); }
.skip:focus { left: 12px; }

/* --- Top Bar ------------------------------------------------------- */
.topbar {
  background: var(--c-dark);
  color: rgba(255,255,255,.65);
  font-size: 13px;
  letter-spacing: .01em;
}
.topbar-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 8px;
  padding-top: 10px;
  padding-bottom: 10px;
}
.topbar a { color: #fff; transition: opacity var(--transition); }
.topbar a:hover { opacity: .8; }

/* --- Header -------------------------------------------------------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(255,255,255,.92);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--c-border);
}
.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
  gap: 20px;
}
.brand {
  display: flex;
  align-items: center;
}
.brand img {
  height: 42px;
  width: auto;
}

.nav {
  display: flex;
  align-items: center;
  gap: 4px;
}
.nav a {
  font-size: 14px;
  font-weight: 600;
  color: var(--c-body);
  padding: 7px 14px;
  border-radius: 6px;
  transition: color var(--transition), background var(--transition);
}
.nav a:hover { color: var(--c-ink); background: var(--c-surface); }
.nav a[aria-current="page"] { color: var(--c-ink); background: var(--c-surface); }

.header-cta {
  display: flex;
  align-items: center;
  gap: 8px;
}

.nav-toggle {
  display: none;
  appearance: none;
  border: 1px solid var(--c-border);
  background: #fff;
  border-radius: 6px;
  padding: 6px 12px;
  font-size: 14px;
  font-weight: 600;
  cursor: pointer;
}

/* --- Buttons ------------------------------------------------------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 24px;
  border: 2px solid transparent;
  border-radius: var(--radius);
  font-size: 14px;
  font-weight: 700;
  cursor: pointer;
  transition: all var(--transition);
  white-space: nowrap;
  font-family: var(--font-body);
  letter-spacing: .01em;
}
.btn:active { transform: translateY(1px); }
.btn:hover { transform: translateY(-1px); }

.btn-primary {
  background: linear-gradient(135deg, var(--c-brand) 0%, var(--c-brand-hover) 100%);
  color: #fff;
  box-shadow: 0 4px 14px rgba(42,124,159,.25);
}
.btn-primary:hover {
  box-shadow: 0 6px 20px rgba(42,124,159,.35);
}

.btn-outline {
  background: transparent;
  color: var(--c-ink);
  border-color: var(--c-border);
}
.btn-outline:hover {
  background: var(--c-surface);
  border-color: var(--c-brand);
  color: var(--c-brand);
}

.btn-white {
  background: #fff;
  color: var(--c-brand);
  border-color: transparent;
  font-weight: 700;
}
.btn-white:hover {
  background: rgba(255,255,255,.95);
  box-shadow: 0 4px 16px rgba(0,0,0,.15);
}

.btn-lg {
  padding: 16px 32px;
  font-size: 16px;
  border-radius: 8px;
  font-weight: 700;
}

/* --- Hero (dark) --------------------------------------------------- */
.hero-dark {
  background: linear-gradient(135deg, var(--c-dark) 0%, var(--c-dark-2) 100%);
  color: #fff;
  position: relative;
  overflow: hidden;
}
.hero-dark::before {
  content: "";
  position: absolute;
  inset: 0;
  background:
    radial-gradient(ellipse 50% 50% at 30% 30%, rgba(42,124,159,.18) 0%, transparent 60%),
    linear-gradient(180deg, transparent 0%, rgba(0,0,0,.15) 100%);
  pointer-events: none;
}
.hero-content {
  position: relative;
  padding: 80px 0 64px;
}

/* Full-width hero with image background option */
.hero-split {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 64px;
  align-items: center;
}
.hero-text { max-width: 640px; }

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background: rgba(42,124,159,.15);
  color: #7dc4e8;
  font-size: 11px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: .1em;
  padding: 8px 16px;
  border-radius: 6px;
  border: 1px solid rgba(125,196,232,.25);
  margin-bottom: 28px;
}
.hero-dark h1 {
  font-family: var(--font-display);
  font-size: clamp(36px, 5.2vw, 64px);
  font-weight: 800;
  line-height: 1.05;
  letter-spacing: -.025em;
  margin-bottom: 24px;
  color: #fff;
}
.hero-dark .hero-sub {
  font-size: 18px;
  line-height: 1.65;
  color: rgba(255,255,255,.7);
  max-width: 560px;
  margin-bottom: 36px;
}
.hero-actions {
  display: flex;
  gap: 14px;
  flex-wrap: wrap;
}

/* Hero image */
.hero-image {
  position: relative;
  border-radius: var(--radius-lg);
  overflow: hidden;
  border: 1px solid rgba(255,255,255,.1);
  box-shadow: 0 20px 60px rgba(0,0,0,.4);
}
.hero-image img {
  width: 100%;
  height: 360px;
  object-fit: cover;
  object-position: center 35%;
}
.hero-image-label {
  position: absolute;
  bottom: 14px;
  left: 14px;
  background: rgba(15,20,25,.85);
  backdrop-filter: blur(10px);
  color: rgba(255,255,255,.9);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: .04em;
  text-transform: uppercase;
  padding: 6px 12px;
  border-radius: 5px;
  border: 1px solid rgba(255,255,255,.15);
}

/* Stats row inside hero */
.stats-row {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 2px;
  background: rgba(0,0,0,.2);
  border-radius: 10px;
  overflow: hidden;
  margin-top: 56px;
  border: 1px solid rgba(255,255,255,.1);
}
.stat {
  background: rgba(255,255,255,.06);
  backdrop-filter: blur(20px);
  padding: 28px 24px;
  text-align: center;
}
.stat-value {
  font-family: var(--font-display);
  font-size: 26px;
  font-weight: 800;
  color: #fff;
  margin-bottom: 6px;
  letter-spacing: -.01em;
}
.stat-label {
  font-size: 13px;
  color: rgba(255,255,255,.5);
  font-weight: 500;
}

/* --- Hero (light, inner pages) ------------------------------------- */
.hero-light {
  background: var(--c-surface);
  border-bottom: 1px solid var(--c-border);
  padding: 56px 0 48px;
}
.hero-light .hero-label {
  font-size: 12px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: .08em;
  color: var(--c-brand);
  margin-bottom: 10px;
}
.hero-light h1 {
  font-family: var(--font-display);
  font-size: clamp(28px, 4vw, 40px);
  font-weight: 800;
  line-height: 1.12;
  letter-spacing: -.015em;
  margin-bottom: 12px;
}
.hero-light p {
  font-size: 17px;
  color: var(--c-body);
  max-width: 600px;
}

/* --- Sections ------------------------------------------------------ */
.section {
  padding: 80px 0;
}
.section + .section {
  border-top: 1px solid var(--c-border);
}
.section-alt {
  background: var(--c-surface);
}

.section-header {
  margin-bottom: 48px;
}
.section-header h2 {
  font-family: var(--font-display);
  font-size: clamp(24px, 3vw, 34px);
  font-weight: 800;
  line-height: 1.15;
  letter-spacing: -.01em;
  margin-bottom: 10px;
}
.section-header p {
  font-size: 17px;
  color: var(--c-body);
  max-width: 520px;
}

/* --- Cards --------------------------------------------------------- */
.card-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}
.card {
  background: #fff;
  border: 2px solid var(--c-border);
  border-radius: var(--radius-lg);
  padding: 36px 32px;
  transition: all var(--transition);
  position: relative;
}
.card::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: linear-gradient(90deg, var(--c-brand) 0%, var(--c-brand-hover) 100%);
  border-radius: var(--radius-lg) var(--radius-lg) 0 0;
  opacity: 0;
  transition: opacity var(--transition);
}
.card:hover {
  border-color: var(--c-brand);
  box-shadow: var(--shadow-lg);
  transform: translateY(-2px);
}
.card:hover::before {
  opacity: 1;
}
.card-icon {
  width: 56px;
  height: 56px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 10px;
  background: linear-gradient(135deg, var(--c-brand) 0%, var(--c-brand-hover) 100%);
  color: #fff;
  font-size: 24px;
  margin-bottom: 24px;
  font-weight: 800;
  font-family: var(--font-display);
  box-shadow: 0 4px 12px rgba(42,124,159,.2);
}
.card h3 {
  font-family: var(--font-display);
  font-size: 19px;
  font-weight: 700;
  margin-bottom: 12px;
  color: var(--c-ink);
  line-height: 1.3;
}
.card p {
  font-size: 15px;
  color: var(--c-body);
  line-height: 1.6;
}

/* --- Photo Strip (homepage) ---------------------------------------- */
.photo-strip {
  background: var(--c-surface);
  border-top: 1px solid var(--c-border);
  border-bottom: 1px solid var(--c-border);
  padding: 48px 0;
}
.photo-strip-grid {
  display: grid;
  grid-template-columns: 1.4fr 1fr;
  gap: 20px;
}
.photo-strip-img {
  border-radius: var(--radius-lg);
  overflow: hidden;
  border: 1px solid var(--c-border);
  box-shadow: var(--shadow-sm);
}
.photo-strip-img img {
  width: 100%;
  height: 320px;
  object-fit: cover;
  object-position: center 35%;
}

/* --- Feature Photo (in two-col layouts) ---------------------------- */
.feature-photo {
  border-radius: var(--radius-lg);
  overflow: hidden;
  border: 1px solid var(--c-border);
  box-shadow: var(--shadow-md);
  align-self: center;
}
.feature-photo img {
  width: 100%;
  height: 100%;
  min-height: 300px;
  max-height: 440px;
  object-fit: cover;
  object-position: center 40%;
}

/* --- Two-column layout --------------------------------------------- */
.two-col {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 48px;
  align-items: start;
}

/* --- Spec Table ----------------------------------------------------- */
.spec-table {
  width: 100%;
  border-collapse: collapse;
}
.spec-table th,
.spec-table td {
  text-align: left;
  padding: 14px 16px;
  border-bottom: 1px solid var(--c-border);
  vertical-align: top;
}
.spec-table th {
  font-size: 13px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: .04em;
  color: var(--c-muted);
  width: 35%;
}
.spec-table td {
  color: var(--c-ink);
  font-size: 15px;
}
.spec-table tr:last-child th,
.spec-table tr:last-child td { border-bottom: none; }

/* --- Checklist ----------------------------------------------------- */
.checklist {
  padding: 0;
}
.checklist li {
  position: relative;
  padding: 14px 0 14px 36px;
  font-size: 15px;
  color: var(--c-body);
  border-bottom: 1px solid var(--c-border);
  line-height: 1.5;
}
.checklist li:last-child { border-bottom: none; }
.checklist li::before {
  content: "";
  position: absolute;
  left: 4px;
  top: 20px;
  width: 8px;
  height: 8px;
  background: var(--c-brand);
  border-radius: 50%;
}
.checklist li strong {
  color: var(--c-ink);
}

/* --- Blockquote ---------------------------------------------------- */
.bq {
  border-left: 3px solid var(--c-brand);
  padding: 20px 24px;
  font-size: 17px;
  font-style: italic;
  color: var(--c-body);
  line-height: 1.7;
  max-width: 720px;
}
.bq cite {
  display: block;
  margin-top: 12px;
  font-style: normal;
  font-size: 14px;
  font-weight: 700;
  color: var(--c-ink);
}

/* --- Quote Form ---------------------------------------------------- */
.form-card {
  background: #fff;
  border: 1px solid var(--c-border);
  border-radius: var(--radius-lg);
  padding: 40px;
  box-shadow: var(--shadow-sm);
}
.form-card h2 {
  font-family: var(--font-display);
  font-size: 24px;
  font-weight: 800;
  margin-bottom: 6px;
}
.form-card .form-sub {
  font-size: 15px;
  color: var(--c-body);
  margin-bottom: 28px;
}

label {
  display: block;
  font-size: 13px;
  font-weight: 700;
  color: var(--c-ink);
  margin-bottom: 6px;
  margin-top: 20px;
}

input, select, textarea {
  width: 100%;
  padding: 11px 14px;
  border: 1px solid var(--c-border);
  border-radius: var(--radius);
  font: inherit;
  font-size: 15px;
  color: var(--c-ink);
  background: #fff;
  transition: border-color var(--transition), box-shadow var(--transition);
}
input:focus, select:focus, textarea:focus {
  outline: none;
  border-color: var(--c-brand);
  box-shadow: 0 0 0 3px rgba(42,124,159,.15);
}
textarea { min-height: 110px; resize: vertical; }
::placeholder { color: var(--c-muted); }

.form-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
}
.form-row label { margin-top: 20px; }

.form-footer {
  margin-top: 28px;
  display: flex;
  align-items: center;
  gap: 16px;
  flex-wrap: wrap;
}
.form-note {
  font-size: 13px;
  color: var(--c-muted);
}
.form-note a { color: var(--c-brand); font-weight: 600; }
.form-note a:hover { text-decoration: underline; }

/* --- Contact cards ------------------------------------------------- */
.contact-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
  margin-bottom: 48px;
}
.contact-card {
  background: var(--c-surface);
  border: 1px solid var(--c-border);
  border-radius: var(--radius-lg);
  padding: 28px 24px;
}
.contact-card h3 {
  font-family: var(--font-display);
  font-size: 16px;
  font-weight: 700;
  margin-bottom: 4px;
}
.contact-card .role {
  font-size: 13px;
  color: var(--c-muted);
  margin-bottom: 18px;
}
.contact-card p {
  font-size: 14px;
  color: var(--c-body);
  line-height: 1.8;
}
.contact-card a {
  color: var(--c-brand);
  font-weight: 600;
}
.contact-card a:hover { text-decoration: underline; }

/* --- CTA Banner ---------------------------------------------------- */
.cta-banner {
  background: linear-gradient(135deg, var(--c-brand) 0%, var(--c-brand-dark) 100%);
  color: #fff;
  border-radius: var(--radius-lg);
  padding: 64px 56px;
  text-align: center;
  position: relative;
  overflow: hidden;
  border: 1px solid rgba(255,255,255,.1);
  box-shadow: var(--shadow-lg);
}
.cta-banner::before {
  content: "";
  position: absolute;
  inset: 0;
  background:
    radial-gradient(ellipse 50% 60% at 30% 40%, rgba(255,255,255,.08) 0%, transparent 60%),
    radial-gradient(ellipse 60% 50% at 70% 60%, rgba(0,0,0,.15) 0%, transparent 60%);
  pointer-events: none;
}
.cta-banner h2 {
  font-family: var(--font-display);
  font-size: clamp(26px, 3.5vw, 38px);
  font-weight: 800;
  margin-bottom: 14px;
  position: relative;
  letter-spacing: -.015em;
}
.cta-banner p {
  color: rgba(255,255,255,.75);
  font-size: 17px;
  margin-bottom: 32px;
  position: relative;
  max-width: 480px;
  margin-left: auto;
  margin-right: auto;
}
.cta-banner .hero-actions {
  justify-content: center;
  position: relative;
}

/* --- Footer -------------------------------------------------------- */
.site-footer {
  border-top: 1px solid var(--c-border);
  padding: 28px 0;
  color: var(--c-muted);
  font-size: 13px;
}
.footer-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 12px;
}
.footer-inner a { color: var(--c-body); font-weight: 600; }
.footer-inner a:hover { color: var(--c-ink); }

/* --- Responsive ---------------------------------------------------- */
@media (max-width: 900px) {
  .card-grid { grid-template-columns: 1fr; gap: 16px; }
  .two-col { grid-template-columns: 1fr; gap: 32px; }
  .contact-grid { grid-template-columns: 1fr; gap: 16px; }
  .stats-row { grid-template-columns: 1fr; }
  .hero-content { padding: 48px 0 40px; }
  .hero-split { grid-template-columns: 1fr; gap: 32px; }
  .hero-image img { height: 240px; }
  .photo-strip-grid { grid-template-columns: 1fr; }
  .photo-strip-img img { height: 240px; }
  .section { padding: 56px 0; }
  .section-header { margin-bottom: 32px; }
}

@media (max-width: 680px) {
  .header-cta { display: none; }
  .nav-toggle { display: block; }
  .nav {
    display: none;
    position: absolute;
    top: 64px;
    left: 0;
    right: 0;
    flex-direction: column;
    background: #fff;
    border-bottom: 1px solid var(--c-border);
    padding: 8px 16px;
    box-shadow: var(--shadow-md);
  }
  .nav[data-open="true"] { display: flex; }
  .nav a { padding: 12px 8px; border-radius: 6px; }

  .form-row { grid-template-columns: 1fr; gap: 0; }
  .form-card { padding: 24px; }
  .hero-dark h1 { font-size: 28px; }
  .hero-content { padding: 36px 0 32px; }
  .section { padding: 40px 0; }
  .section-header { margin-bottom: 24px; }
  .cta-banner { padding: 36px 24px; }
  .topbar-inner { font-size: 12px; flex-direction: column; align-items: flex-start; }
  .hero-light { padding: 40px 0 32px; }
  .card { padding: 24px 20px; }
  .contact-card { padding: 20px; }
  .stats-row { margin-top: 32px; }
  .stat { padding: 18px 16px; }
  .stat-value { font-size: 19px; }
}