/* ==========================================================================
   Soundproofing for Apartments - Global Styles
   A calm, practical micro-niche site about noise reduction
   ========================================================================== */

/* CSS Custom Properties */
:root {
  /* Colors - Calm, muted palette */
  --color-primary: #4f6d7a;
  --color-primary-dark: #3d5561;
  --color-primary-light: #7a9aa8;
  --color-accent: #6b8e23;
  --color-accent-light: #8fbc3c;
  
  --color-text: #2d3436;
  --color-text-light: #555f61;
  --color-text-muted: #7c8a8d;
  
  --color-bg: #ffffff;
  --color-bg-alt: #f7f9fa;
  --color-bg-warm: #faf8f5;
  --color-border: #e2e8eb;
  --color-border-light: #eef2f4;
  
  /* Typography */
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-serif: 'Georgia', 'Times New Roman', serif;
  
  /* Spacing */
  --space-xs: 0.25rem;
  --space-sm: 0.5rem;
  --space-md: 1rem;
  --space-lg: 1.5rem;
  --space-xl: 2rem;
  --space-2xl: 3rem;
  --space-3xl: 4rem;
  
  /* Borders */
  --radius: 6px;
  --radius-lg: 10px;
  --radius-xl: 16px;
  
  /* Shadows */
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.06);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.08);
  --shadow-lg: 0 8px 30px rgba(0,0,0,0.1);
  
  /* Transitions */
  --transition: 0.2s ease;
  --transition-slow: 0.3s ease;
}

/* Reset & Base */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font-sans);
  font-size: 1rem;
  line-height: 1.7;
  color: var(--color-text);
  background: var(--color-bg);
}

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

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

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

/* Typography */
h1, h2, h3, h4, h5, h6 {
  font-weight: 600;
  line-height: 1.3;
  color: var(--color-text);
  margin-bottom: var(--space-md);
}

h1 { font-size: clamp(1.75rem, 4vw, 2.5rem); }
h2 { font-size: clamp(1.4rem, 3vw, 1.875rem); margin-top: var(--space-2xl); }
h3 { font-size: clamp(1.15rem, 2.5vw, 1.375rem); margin-top: var(--space-xl); }
h4 { font-size: 1.125rem; }

p {
  margin-bottom: var(--space-md);
}

ul, ol {
  margin-bottom: var(--space-md);
  padding-left: var(--space-lg);
}

li {
  margin-bottom: var(--space-sm);
}

strong {
  font-weight: 600;
}

/* Container */
.container {
  width: 100%;
  max-width: 1140px;
  margin: 0 auto;
  padding: 0 var(--space-md);
}

@media (min-width: 768px) {
  .container {
    padding: 0 var(--space-xl);
  }
}

.content-container {
  max-width: 760px;
}

/* ==========================================================================
   Header & Navigation
   ========================================================================== */

.site-header {
  background: var(--color-bg);
  border-bottom: 1px solid var(--color-border);
  position: sticky;
  top: 0;
  z-index: 100;
}

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-md) var(--space-md);
  max-width: 1140px;
  margin: 0 auto;
}

@media (min-width: 768px) {
  .nav {
    padding: var(--space-md) var(--space-xl);
  }
}

.logo {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  font-weight: 700;
  font-size: 1.125rem;
  color: var(--color-text);
}

.logo:hover {
  color: var(--color-primary);
}

.logo svg {
  width: 28px;
  height: 28px;
}

.nav-links {
  display: none;
  gap: var(--space-lg);
}

@media (min-width: 768px) {
  .nav-links {
    display: flex;
  }
}

.nav-links a {
  font-size: 0.9375rem;
  font-weight: 500;
  color: var(--color-text-light);
  padding: var(--space-sm) 0;
  position: relative;
}

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

.nav-links a::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--color-primary);
  transition: width var(--transition);
}

.nav-links a:hover::after {
  width: 100%;
}

/* Mobile Navigation */
.nav-toggle {
  display: flex;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: var(--space-sm);
}

@media (min-width: 768px) {
  .nav-toggle {
    display: none;
  }
}

.nav-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--color-text);
  transition: var(--transition);
}

.mobile-menu {
  display: none;
  flex-direction: column;
  background: var(--color-bg);
  border-bottom: 1px solid var(--color-border);
  padding: var(--space-md);
}

.mobile-menu.active {
  display: flex;
}

.mobile-menu a {
  padding: var(--space-md);
  border-bottom: 1px solid var(--color-border-light);
  color: var(--color-text);
  font-weight: 500;
}

.mobile-menu a:last-child {
  border-bottom: none;
}

/* ==========================================================================
   Hero Section
   ========================================================================== */

.hero {
  padding: var(--space-3xl) 0;
  background: linear-gradient(180deg, var(--color-bg-alt) 0%, var(--color-bg) 100%);
  overflow: hidden;
}

@media (min-width: 768px) {
  .hero {
    padding: 5rem 0;
  }
}

.hero-grid {
  display: grid;
  gap: var(--space-2xl);
  align-items: center;
}

@media (min-width: 768px) {
  .hero-grid {
    grid-template-columns: 1fr 1fr;
    gap: var(--space-3xl);
  }
}

@media (min-width: 1024px) {
  .hero-grid {
    grid-template-columns: 1.1fr 0.9fr;
  }
}

.hero-content h1 {
  margin-bottom: var(--space-lg);
}

.hero-content p {
  font-size: 1.125rem;
  color: var(--color-text-light);
  margin-bottom: var(--space-xl);
}

.hero-cta {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-md);
}

/* Hero Image with Glow */
.hero-image {
  display: flex;
  justify-content: center;
  align-items: center;
}

.hero-image-wrapper {
  position: relative;
  display: flex;
  justify-content: center;
  align-items: center;
}

.hero-image-wrapper::before {
  content: '';
  position: absolute;
  width: 100%;
  height: 100%;
  background: radial-gradient(circle, rgba(79, 109, 122, 0.35) 0%, rgba(79, 109, 122, 0.1) 40%, transparent 70%);
  border-radius: 50%;
  filter: blur(40px);
  transform: scale(1.3);
  z-index: 0;
  animation: pulse-glow 4s ease-in-out infinite;
}

@keyframes pulse-glow {
  0%, 100% { opacity: 0.6; transform: scale(1.3); }
  50% { opacity: 1; transform: scale(1.4); }
}

.hero-image-wrapper img {
  position: relative;
  z-index: 1;
  width: 100%;
  max-width: 380px;
  height: auto;
  border-radius: 50%;
  object-fit: cover;
  aspect-ratio: 1;
  box-shadow: 0 0 0 4px rgba(255,255,255,0.8), 0 0 40px rgba(79,109,122,0.25), 0 20px 50px rgba(0,0,0,0.12);
}

@media (max-width: 767px) {
  .hero-image { order: -1; }
  .hero-image-wrapper img { max-width: 240px; }
}

/* ==========================================================================
   Buttons
   ========================================================================== */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-sm);
  padding: 0.875rem 1.5rem;
  border-radius: var(--radius);
  font-weight: 600;
  font-size: 0.9375rem;
  transition: all var(--transition);
  cursor: pointer;
  border: none;
}

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

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

.btn-secondary {
  background: transparent;
  color: var(--color-primary);
  border: 2px solid var(--color-border);
}

.btn-secondary:hover {
  border-color: var(--color-primary);
  background: var(--color-bg-alt);
}

/* ==========================================================================
   Sections
   ========================================================================== */

.section {
  padding: var(--space-3xl) 0;
}

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

.section-header {
  text-align: center;
  margin-bottom: var(--space-2xl);
}

.section-header h2 {
  margin-top: 0;
  margin-bottom: var(--space-sm);
}

.section-header p {
  color: var(--color-text-light);
  font-size: 1.0625rem;
  margin-bottom: 0;
}

/* ==========================================================================
   Article Cards
   ========================================================================== */

.article-grid {
  display: grid;
  gap: var(--space-lg);
}

@media (min-width: 640px) {
  .article-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 960px) {
  .article-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

.article-card {
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-lg);
  transition: all var(--transition);
}

.article-card:hover {
  border-color: var(--color-primary-light);
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}

.article-card .category {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--color-primary);
  background: rgba(79, 109, 122, 0.1);
  padding: 0.25rem 0.625rem;
  border-radius: 4px;
  margin-bottom: var(--space-md);
}

.article-card h3 {
  font-size: 1.125rem;
  margin-top: 0;
  margin-bottom: var(--space-sm);
}

.article-card h3 a {
  color: var(--color-text);
}

.article-card h3 a:hover {
  color: var(--color-primary);
}

.article-card p {
  font-size: 0.9375rem;
  color: var(--color-text-light);
  margin-bottom: var(--space-md);
}

.article-card .read-more {
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--color-primary);
}

.article-card .read-more:hover {
  color: var(--color-primary-dark);
}

/* ==========================================================================
   Article Content
   ========================================================================== */

.article-header {
  padding: var(--space-2xl) 0;
  background: var(--color-bg-alt);
  border-bottom: 1px solid var(--color-border);
}

.breadcrumb {
  font-size: 0.875rem;
  color: var(--color-text-muted);
  margin-bottom: var(--space-lg);
}

.breadcrumb a {
  color: var(--color-text-muted);
}

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

.article-meta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-md);
  font-size: 0.875rem;
  color: var(--color-text-muted);
  margin-top: var(--space-lg);
}

.article-meta .divider {
  width: 4px;
  height: 4px;
  border-radius: 50%;
  background: var(--color-text-muted);
}

.article-content {
  padding: var(--space-2xl) 0 var(--space-3xl);
}

.article-content h2 {
  padding-top: var(--space-md);
  border-top: 1px solid var(--color-border-light);
}

.article-content h2:first-of-type {
  border-top: none;
  padding-top: 0;
}

.article-content a {
  text-decoration: underline;
  text-underline-offset: 2px;
}

.article-content a:hover {
  color: var(--color-primary-dark);
}

/* Table of Contents */
.toc {
  background: var(--color-bg-alt);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-lg);
  margin-bottom: var(--space-2xl);
}

.toc h4 {
  font-size: 0.875rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--color-text-muted);
  margin-bottom: var(--space-md);
}

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

.toc li {
  margin-bottom: var(--space-sm);
}

.toc a {
  font-size: 0.9375rem;
  color: var(--color-text-light);
  text-decoration: none;
}

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

/* Highlight Boxes */
.highlight-box {
  background: var(--color-bg-alt);
  border-left: 4px solid var(--color-primary);
  border-radius: 0 var(--radius) var(--radius) 0;
  padding: var(--space-lg);
  margin: var(--space-xl) 0;
}

.highlight-box h4 {
  margin-bottom: var(--space-sm);
  font-size: 1rem;
}

.highlight-box p:last-child {
  margin-bottom: 0;
}

.highlight-box.tip {
  border-left-color: var(--color-accent);
  background: rgba(107, 142, 35, 0.06);
}

.highlight-box.warning {
  border-left-color: #d97706;
  background: rgba(217, 119, 6, 0.06);
}

.highlight-box.important {
  border-left-color: #dc2626;
  background: rgba(220, 38, 38, 0.06);
}

/* Comparison Tables */
.table-wrapper {
  overflow-x: auto;
  margin: var(--space-xl) 0;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
}

.comparison-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.9375rem;
}

.comparison-table th,
.comparison-table td {
  padding: var(--space-md);
  text-align: left;
  border-bottom: 1px solid var(--color-border-light);
}

.comparison-table th {
  background: var(--color-bg-alt);
  font-weight: 600;
  font-size: 0.875rem;
  text-transform: uppercase;
  letter-spacing: 0.03em;
  color: var(--color-text-light);
}

.comparison-table tr:last-child td {
  border-bottom: none;
}

.comparison-table tr:hover td {
  background: var(--color-bg-alt);
}

/* ==========================================================================
   Product Cards
   ========================================================================== */

.product-card {
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-xl);
  margin: var(--space-xl) 0;
}

.product-card h3 {
  margin-top: 0;
  color: var(--color-primary-dark);
}

.product-card .specs {
  display: grid;
  gap: var(--space-sm);
  margin: var(--space-lg) 0;
  padding: var(--space-md);
  background: var(--color-bg-alt);
  border-radius: var(--radius);
}

.product-card .spec {
  display: flex;
  gap: var(--space-md);
  font-size: 0.9375rem;
}

.product-card .spec-label {
  font-weight: 600;
  color: var(--color-text-light);
  min-width: 140px;
}

.product-card .pros-cons {
  display: grid;
  gap: var(--space-lg);
  margin: var(--space-lg) 0;
}

@media (min-width: 640px) {
  .product-card .pros-cons {
    grid-template-columns: 1fr 1fr;
  }
}

.product-card .pros h4,
.product-card .cons h4 {
  font-size: 0.9375rem;
  margin-bottom: var(--space-sm);
}

.product-card .pros h4 { color: var(--color-accent); }
.product-card .cons h4 { color: #dc2626; }

.product-card .pros ul,
.product-card .cons ul {
  font-size: 0.9375rem;
  padding-left: var(--space-lg);
}

.cta-btn {
  display: inline-block;
  background: var(--color-primary);
  color: white;
  padding: 0.75rem 1.5rem;
  border-radius: var(--radius);
  font-weight: 600;
  font-size: 0.9375rem;
  margin-top: var(--space-md);
  transition: background var(--transition);
}

.cta-btn:hover {
  background: var(--color-primary-dark);
  color: white;
}

/* ==========================================================================
   FAQ Accordion
   ========================================================================== */

.faq-section {
  margin: var(--space-xl) 0;
}

.faq-item {
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  margin-bottom: var(--space-md);
  overflow: hidden;
}

.faq-question {
  width: 100%;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: var(--space-lg);
  background: var(--color-bg);
  border: none;
  cursor: pointer;
  font-size: 1rem;
  font-weight: 600;
  text-align: left;
  color: var(--color-text);
  transition: background var(--transition);
}

.faq-question:hover {
  background: var(--color-bg-alt);
}

.faq-question svg {
  flex-shrink: 0;
  transition: transform var(--transition);
}

.faq-item.active .faq-question svg {
  transform: rotate(180deg);
}

.faq-answer {
  display: none;
  padding: 0 var(--space-lg) var(--space-lg);
  background: var(--color-bg);
}

.faq-item.active .faq-answer {
  display: block;
}

.faq-answer p:last-child {
  margin-bottom: 0;
}

/* ==========================================================================
   Related Articles
   ========================================================================== */

.related-articles {
  margin-top: var(--space-3xl);
  padding-top: var(--space-2xl);
  border-top: 1px solid var(--color-border);
}

.related-articles h3 {
  margin-top: 0;
  margin-bottom: var(--space-lg);
}

.related-grid {
  display: grid;
  gap: var(--space-md);
}

@media (min-width: 640px) {
  .related-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 960px) {
  .related-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

.related-card {
  padding: var(--space-lg);
  background: var(--color-bg-alt);
  border-radius: var(--radius);
  border: 1px solid var(--color-border-light);
}

.related-card h4 {
  font-size: 1rem;
  margin-bottom: var(--space-sm);
}

.related-card h4 a {
  color: var(--color-text);
}

.related-card h4 a:hover {
  color: var(--color-primary);
}

.related-card p {
  font-size: 0.875rem;
  color: var(--color-text-light);
  margin-bottom: 0;
}

/* ==========================================================================
   Hub Pages
   ========================================================================== */

.hub-hero {
  padding: var(--space-2xl) 0;
  background: var(--color-bg-alt);
  border-bottom: 1px solid var(--color-border);
  text-align: center;
}

.hub-hero h1 {
  margin-bottom: var(--space-sm);
}

.hub-hero p {
  color: var(--color-text-light);
  font-size: 1.0625rem;
  max-width: 600px;
  margin: 0 auto;
}

/* ==========================================================================
   Legal Pages
   ========================================================================== */

.legal-content {
  padding: var(--space-2xl) 0 var(--space-3xl);
}

.legal-content h1 {
  margin-bottom: var(--space-sm);
}

.legal-content .last-updated {
  color: var(--color-text-muted);
  font-size: 0.875rem;
  margin-bottom: var(--space-2xl);
}

/* ==========================================================================
   Footer
   ========================================================================== */

.site-footer {
  background: var(--color-text);
  color: rgba(255,255,255,0.8);
  padding: var(--space-3xl) 0 var(--space-xl);
}

.footer-grid {
  display: grid;
  gap: var(--space-2xl);
  margin-bottom: var(--space-2xl);
}

@media (min-width: 768px) {
  .footer-grid {
    grid-template-columns: 2fr 1fr 1fr 1fr;
    gap: var(--space-3xl);
  }
}

.footer-brand p {
  font-size: 0.9375rem;
  opacity: 0.8;
  margin-top: var(--space-md);
}

.footer-links h4 {
  color: white;
  font-size: 0.875rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: var(--space-md);
}

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

.footer-links li {
  margin-bottom: var(--space-sm);
}

.footer-links a {
  color: rgba(255,255,255,0.7);
  font-size: 0.9375rem;
}

.footer-links a:hover {
  color: white;
}

.footer-bottom {
  display: flex;
  flex-direction: column;
  gap: var(--space-md);
  padding-top: var(--space-xl);
  border-top: 1px solid rgba(255,255,255,0.1);
  font-size: 0.875rem;
}

@media (min-width: 640px) {
  .footer-bottom {
    flex-direction: row;
    justify-content: space-between;
    align-items: center;
  }
}

.footer-legal {
  display: flex;
  gap: var(--space-lg);
}

.footer-legal a {
  color: rgba(255,255,255,0.6);
  font-size: 0.875rem;
}

.footer-legal a:hover {
  color: white;
}

/* ==========================================================================
   Ad Placements
   ========================================================================== */

.ad-slot {
  display: flex;
  justify-content: center;
  align-items: center;
  background: var(--color-bg-alt);
  border: 1px dashed var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-md);
  margin: var(--space-xl) 0;
  min-height: 100px;
  text-align: center;
  color: var(--color-text-muted);
  font-size: 0.875rem;
}

.ad-slot::before {
  content: 'Advertisement';
  display: block;
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--color-text-muted);
}

.ad-article-bottom {
  margin: var(--space-2xl) 0;
  padding: var(--space-xl);
  background: var(--color-bg-alt);
  border-radius: var(--radius-lg);
}

.ad-between-sections {
  padding: var(--space-xl) 0;
}

.ad-between-sections .ad-slot {
  max-width: 728px;
  margin: 0 auto;
}

/* ==========================================================================
   Utility Classes
   ========================================================================== */

.text-center { text-align: center; }
.mt-4 { margin-top: var(--space-xl); }
.mb-4 { margin-bottom: var(--space-xl); }