/* HardWaterHQ - Main Stylesheet */
/* Blues and whites, professional, trust-building */

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

:root {
  --blue-dark:    #0a3d6b;
  --blue-mid:     #1565c0;
  --blue-light:   #1e88e5;
  --blue-pale:    #e3f2fd;
  --blue-border:  #bbdefb;
  --white:        #ffffff;
  --gray-light:   #f5f7fa;
  --gray-mid:     #e0e6ef;
  --gray-text:    #4a5568;
  --gray-dark:    #2d3748;
  --accent:       #0288d1;
  --accent-hover: #0277bd;
  --warn:         #e65100;
  --font-base:    -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
  --max-width:    1100px;
  --radius:       8px;
  --shadow:       0 2px 8px rgba(10,61,107,0.10);
  --shadow-lg:    0 4px 24px rgba(10,61,107,0.14);
}

html { scroll-behavior: smooth; }

body {
  font-family: var(--font-base);
  font-size: 17px;
  line-height: 1.7;
  color: var(--gray-dark);
  background: var(--white);
}

a { color: var(--blue-mid); text-decoration: none; }
a:hover { color: var(--accent); text-decoration: underline; }

img { max-width: 100%; height: auto; }

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

/* ===== HEADER / NAV ===== */
.site-header {
  background: var(--blue-dark);
  color: var(--white);
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: 0 2px 8px rgba(0,0,0,0.18);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}

.site-logo {
  font-size: 1.4rem;
  font-weight: 700;
  color: var(--white);
  letter-spacing: -0.5px;
}

.site-logo span { color: #90caf9; }
.site-logo:hover { text-decoration: none; color: var(--white); }

.site-nav { display: flex; gap: 0; }
.site-nav a {
  color: rgba(255,255,255,0.87);
  padding: 8px 14px;
  border-radius: var(--radius);
  font-size: 0.93rem;
  font-weight: 500;
  transition: background 0.15s, color 0.15s;
}
.site-nav a:hover {
  background: rgba(255,255,255,0.12);
  color: var(--white);
  text-decoration: none;
}

.nav-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: 8px;
  color: var(--white);
}

.nav-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--white);
  margin: 5px 0;
  transition: transform 0.2s;
}

/* ===== HERO ===== */
.hero {
  background: linear-gradient(135deg, var(--blue-dark) 0%, var(--blue-mid) 60%, var(--blue-light) 100%);
  color: var(--white);
  padding: 80px 20px 72px;
  text-align: center;
}

.hero h1 {
  font-size: clamp(1.8rem, 4vw, 2.9rem);
  font-weight: 800;
  line-height: 1.2;
  margin-bottom: 18px;
  letter-spacing: -0.5px;
}

.hero p {
  font-size: clamp(1rem, 2vw, 1.2rem);
  max-width: 620px;
  margin: 0 auto 32px;
  opacity: 0.92;
  line-height: 1.6;
}

.btn {
  display: inline-block;
  padding: 14px 30px;
  border-radius: 50px;
  font-weight: 700;
  font-size: 1rem;
  transition: background 0.15s, transform 0.1s, box-shadow 0.15s;
  cursor: pointer;
  border: none;
}

.btn-primary {
  background: var(--white);
  color: var(--blue-dark);
}
.btn-primary:hover {
  background: var(--blue-pale);
  color: var(--blue-dark);
  text-decoration: none;
  transform: translateY(-1px);
  box-shadow: 0 4px 16px rgba(0,0,0,0.18);
}

.btn-outline {
  background: transparent;
  color: var(--white);
  border: 2px solid rgba(255,255,255,0.7);
  margin-left: 12px;
}
.btn-outline:hover {
  background: rgba(255,255,255,0.1);
  color: var(--white);
  text-decoration: none;
}

/* ===== STATS BAR ===== */
.stats-bar {
  background: var(--blue-pale);
  border-bottom: 1px solid var(--blue-border);
  padding: 20px 0;
}

.stats-inner {
  display: flex;
  justify-content: center;
  gap: 48px;
  flex-wrap: wrap;
}

.stat-item {
  text-align: center;
}

.stat-number {
  font-size: 1.6rem;
  font-weight: 800;
  color: var(--blue-dark);
  display: block;
}

.stat-label {
  font-size: 0.82rem;
  color: var(--gray-text);
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

/* ===== SECTION TITLES ===== */
.section-title {
  font-size: 1.6rem;
  font-weight: 700;
  color: var(--blue-dark);
  margin-bottom: 8px;
}

.section-sub {
  color: var(--gray-text);
  margin-bottom: 32px;
  font-size: 1rem;
}

/* ===== CARD GRID ===== */
.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 24px;
}

.card {
  background: var(--white);
  border: 1px solid var(--gray-mid);
  border-radius: var(--radius);
  padding: 28px;
  box-shadow: var(--shadow);
  transition: box-shadow 0.2s, transform 0.2s;
  display: flex;
  flex-direction: column;
}

.card:hover {
  box-shadow: var(--shadow-lg);
  transform: translateY(-2px);
}

.card-tag {
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 1px;
  color: var(--blue-mid);
  margin-bottom: 10px;
}

.card h3 {
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--blue-dark);
  margin-bottom: 10px;
  line-height: 1.35;
}

.card p {
  color: var(--gray-text);
  font-size: 0.93rem;
  line-height: 1.6;
  flex: 1;
  margin-bottom: 18px;
}

.card-link {
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--blue-mid);
}

.card-link::after { content: " →"; }
.card-link:hover { color: var(--accent); text-decoration: none; }

.card-hardness {
  display: inline-block;
  background: var(--blue-pale);
  color: var(--blue-dark);
  font-size: 0.78rem;
  font-weight: 700;
  padding: 3px 10px;
  border-radius: 50px;
  margin-bottom: 12px;
}

/* ===== PAGE SECTIONS ===== */
.section { padding: 64px 0; }
.section-alt { background: var(--gray-light); }
.section-blue { background: var(--blue-pale); }

/* ===== ARTICLE / GUIDE ===== */
.article-header {
  background: linear-gradient(135deg, var(--blue-dark) 0%, var(--blue-mid) 100%);
  color: var(--white);
  padding: 56px 20px 48px;
}

.article-header .breadcrumb {
  font-size: 0.85rem;
  opacity: 0.8;
  margin-bottom: 14px;
}

.article-header .breadcrumb a { color: rgba(255,255,255,0.85); }
.article-header .breadcrumb a:hover { color: var(--white); }
.article-header .breadcrumb span { margin: 0 6px; }

.article-header h1 {
  font-size: clamp(1.6rem, 3.5vw, 2.4rem);
  font-weight: 800;
  line-height: 1.2;
  margin-bottom: 16px;
  letter-spacing: -0.3px;
}

.article-header .meta {
  font-size: 0.88rem;
  opacity: 0.8;
  display: flex;
  gap: 18px;
  flex-wrap: wrap;
}

.article-body {
  max-width: 820px;
  margin: 0 auto;
  padding: 48px 20px 64px;
}

.article-body h2 {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--blue-dark);
  margin: 40px 0 14px;
  padding-top: 8px;
  border-top: 3px solid var(--blue-pale);
}

.article-body h3 {
  font-size: 1.18rem;
  font-weight: 700;
  color: var(--blue-dark);
  margin: 28px 0 10px;
}

.article-body p { margin-bottom: 18px; }

.article-body ul, .article-body ol {
  padding-left: 24px;
  margin-bottom: 18px;
}

.article-body li { margin-bottom: 8px; }

.article-body strong { color: var(--blue-dark); }

/* ===== DATA BOXES ===== */
.data-box {
  background: var(--blue-pale);
  border: 1px solid var(--blue-border);
  border-left: 4px solid var(--blue-mid);
  border-radius: var(--radius);
  padding: 20px 24px;
  margin: 28px 0;
}

.data-box h4 {
  font-size: 0.85rem;
  text-transform: uppercase;
  letter-spacing: 1px;
  color: var(--blue-mid);
  margin-bottom: 12px;
  font-weight: 700;
}

.data-row {
  display: flex;
  justify-content: space-between;
  padding: 6px 0;
  border-bottom: 1px solid var(--blue-border);
  font-size: 0.93rem;
}

.data-row:last-child { border-bottom: none; }
.data-label { color: var(--gray-text); }
.data-value { font-weight: 700; color: var(--blue-dark); }

/* ===== WARNING / CALLOUT ===== */
.callout {
  border-radius: var(--radius);
  padding: 18px 22px;
  margin: 24px 0;
  font-size: 0.95rem;
}

.callout-warning {
  background: #fff3e0;
  border-left: 4px solid var(--warn);
  color: #4e342e;
}

.callout-info {
  background: var(--blue-pale);
  border-left: 4px solid var(--blue-light);
  color: var(--blue-dark);
}

.callout-success {
  background: #e8f5e9;
  border-left: 4px solid #43a047;
  color: #1b5e20;
}

.callout strong { display: block; margin-bottom: 4px; }

/* ===== FAQ ===== */
.faq-section { margin-top: 40px; }

.faq-item {
  border: 1px solid var(--gray-mid);
  border-radius: var(--radius);
  margin-bottom: 12px;
  overflow: hidden;
}

.faq-question {
  background: var(--gray-light);
  padding: 16px 20px;
  font-weight: 700;
  color: var(--blue-dark);
  font-size: 1rem;
  border-bottom: 1px solid var(--gray-mid);
}

.faq-answer {
  padding: 16px 20px;
  background: var(--white);
  color: var(--gray-dark);
  font-size: 0.95rem;
  line-height: 1.7;
}

/* ===== RELATED LINKS ===== */
.related-section {
  background: var(--blue-pale);
  border-radius: var(--radius);
  padding: 28px;
  margin-top: 40px;
}

.related-section h3 {
  font-size: 1.1rem;
  color: var(--blue-dark);
  margin-bottom: 14px !important;
  border-top: none !important;
  margin-top: 0 !important;
}

.related-links {
  list-style: none;
  padding: 0;
  margin: 0;
}

.related-links li { margin-bottom: 10px; }
.related-links a {
  color: var(--blue-mid);
  font-weight: 600;
  font-size: 0.95rem;
}

.related-links a::before { content: "→ "; }

/* ===== AFFILIATE DISCLAIMER ===== */
.affiliate-note {
  background: var(--gray-light);
  border: 1px solid var(--gray-mid);
  border-radius: var(--radius);
  padding: 14px 18px;
  font-size: 0.82rem;
  color: var(--gray-text);
  margin: 28px 0;
}

/* ===== TABLE ===== */
.data-table {
  width: 100%;
  border-collapse: collapse;
  margin: 24px 0;
  font-size: 0.92rem;
}

.data-table th {
  background: var(--blue-dark);
  color: var(--white);
  padding: 12px 16px;
  text-align: left;
  font-weight: 700;
}

.data-table td {
  padding: 11px 16px;
  border-bottom: 1px solid var(--gray-mid);
}

.data-table tr:nth-child(even) { background: var(--gray-light); }
.data-table tr:hover { background: var(--blue-pale); }

/* ===== FOOTER ===== */
.site-footer {
  background: var(--blue-dark);
  color: rgba(255,255,255,0.75);
  padding: 48px 0 28px;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: 40px;
  margin-bottom: 36px;
}

.footer-brand .site-logo {
  font-size: 1.2rem;
  display: block;
  margin-bottom: 10px;
}

.footer-brand p {
  font-size: 0.88rem;
  line-height: 1.65;
  max-width: 300px;
}

.footer-col h4 {
  color: var(--white);
  font-size: 0.9rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.8px;
  margin-bottom: 14px;
}

.footer-col ul { list-style: none; }
.footer-col li { margin-bottom: 8px; }
.footer-col a {
  color: rgba(255,255,255,0.72);
  font-size: 0.88rem;
}
.footer-col a:hover { color: var(--white); text-decoration: none; }

.footer-bottom {
  border-top: 1px solid rgba(255,255,255,0.12);
  padding-top: 20px;
  font-size: 0.82rem;
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 8px;
}

.footer-bottom a { color: rgba(255,255,255,0.65); }
.footer-bottom a:hover { color: var(--white); }

/* ===== ABOUT PAGE ===== */
.about-hero {
  background: linear-gradient(135deg, var(--blue-dark), var(--blue-mid));
  color: var(--white);
  padding: 64px 20px;
  text-align: center;
}

.about-hero h1 { font-size: 2.2rem; font-weight: 800; margin-bottom: 14px; }
.about-hero p { max-width: 560px; margin: 0 auto; opacity: 0.9; }

.about-body {
  max-width: 760px;
  margin: 0 auto;
  padding: 56px 20px;
}

.about-body h2 {
  font-size: 1.4rem;
  color: var(--blue-dark);
  font-weight: 700;
  margin: 32px 0 12px;
}

.about-body p { margin-bottom: 16px; color: var(--gray-dark); }

/* ===== DISCLOSURE PAGE ===== */
.disclosure-body {
  max-width: 760px;
  margin: 0 auto;
  padding: 56px 20px;
}

.disclosure-body h2 {
  font-size: 1.3rem;
  color: var(--blue-dark);
  font-weight: 700;
  margin: 28px 0 10px;
}

.disclosure-body p, .disclosure-body li {
  color: var(--gray-dark);
  margin-bottom: 14px;
  font-size: 0.97rem;
  line-height: 1.7;
}

/* ===== RESPONSIVE ===== */
@media (max-width: 768px) {
  .site-nav {
    display: none;
    position: absolute;
    top: 64px;
    left: 0;
    right: 0;
    background: var(--blue-dark);
    flex-direction: column;
    padding: 12px 16px 20px;
    border-top: 1px solid rgba(255,255,255,0.1);
    box-shadow: 0 8px 24px rgba(0,0,0,0.2);
  }
  .site-nav.open { display: flex; }
  .nav-toggle { display: block; }

  .footer-grid {
    grid-template-columns: 1fr;
    gap: 24px;
  }

  .stats-inner { gap: 28px; }

  .card-grid { grid-template-columns: 1fr; }

  .hero { padding: 52px 20px 48px; }

  .btn-outline { display: block; margin: 12px auto 0; max-width: 200px; }

  .data-table { font-size: 0.84rem; }
  .data-table th, .data-table td { padding: 9px 10px; }
}

@media (max-width: 480px) {
  body { font-size: 16px; }
  .article-body { padding: 32px 16px 48px; }
}