/*
Theme Name: Shure MV88 Pro Audio Clean SEO
Theme URI: https://mv88.vn
Author: Antigravity Audio SEO Team
Description: Chuyên biệt cho từ khóa MV88 / Shure MV88. Thiết kế chuẩn Hi-Fi Audio, 100% Zero JavaScript, tốc độ tải trang cực đại 100/100 Core Web Vitals, tích hợp Schema Product, AggregateRating, FAQPage và Mobile-First.
Version: 2.0.0
License: GNU General Public License v2 or later
Text Domain: mv88-clean
*/

/* ==========================================================================
   Design Tokens & CSS Variables (Zero-JS Architecture)
   ========================================================================== */
:root {
  --primary: #0f172a;        /* Deep Slate Pro Audio */
  --primary-light: #1e293b;
  --accent: #10b981;         /* Shure Signal Green */
  --accent-hover: #059669;
  --accent-blue: #2563eb;    /* Studio Tech Blue */
  --accent-blue-hover: #1d4ed8;
  --gold: #f59e0b;           /* Review Star Gold */
  
  --bg-page: #f8fafc;
  --bg-surface: #ffffff;
  --bg-surface-elevated: #ffffff;
  --bg-dark: #090d16;
  
  --text-main: #0f172a;
  --text-muted: #64748b;
  --text-light: #94a3b8;
  --text-white: #f8fafc;
  
  --border-light: #e2e8f0;
  --border-focus: #cbd5e1;
  
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --radius-full: 9999px;
  
  --shadow-sm: 0 1px 3px rgba(15, 23, 42, 0.06);
  --shadow-md: 0 4px 12px rgba(15, 23, 42, 0.08);
  --shadow-lg: 0 12px 28px rgba(15, 23, 42, 0.12);
  
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --max-width: 1200px;
}

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

html {
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.65;
  color: var(--text-main);
  background-color: var(--bg-page);
  scroll-behavior: smooth;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
}

body {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

img {
  max-width: 100%;
  height: auto;
  display: block;
  border-radius: var(--radius-sm);
}

a {
  color: var(--accent-blue);
  text-decoration: none;
  transition: all 0.15s ease;
}

a:hover {
  color: var(--accent-blue-hover);
  text-decoration: underline;
}

/* ==========================================================================
   Header & Clean Navigation (0 JS)
   ========================================================================== */
.site-header {
  background: rgba(15, 23, 42, 0.96);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  position: sticky;
  top: 0;
  z-index: 1000;
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.25);
}

.header-container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 1.25rem;
  height: 70px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.brand-wrapper {
  display: flex;
  align-items: center;
  gap: 0.85rem;
  text-decoration: none;
}

.brand-badge {
  background: linear-gradient(135deg, #10b981, #059669);
  color: #fff;
  font-weight: 900;
  font-size: 1.15rem;
  letter-spacing: 1px;
  padding: 0.35rem 0.65rem;
  border-radius: var(--radius-sm);
  display: inline-block;
  box-shadow: 0 0 15px rgba(16, 185, 129, 0.4);
}

.brand-name {
  color: #fff;
  font-size: 1.2rem;
  font-weight: 800;
  letter-spacing: -0.3px;
  line-height: 1.1;
}

.brand-sub {
  display: block;
  font-size: 0.68rem;
  color: var(--text-light);
  letter-spacing: 0.5px;
  text-transform: uppercase;
  font-weight: 600;
}

/* Pure CSS Hamburger Menu */
#nav-toggle {
  display: none;
}

.nav-toggle-btn {
  display: none;
  cursor: pointer;
  padding: 0.5rem;
  background: rgba(255, 255, 255, 0.08);
  border: 1px solid rgba(255, 255, 255, 0.15);
  border-radius: var(--radius-sm);
}

.nav-toggle-icon,
.nav-toggle-icon::before,
.nav-toggle-icon::after {
  content: '';
  display: block;
  width: 22px;
  height: 2px;
  background: #fff;
  position: relative;
  transition: all 0.2s ease;
}

.nav-toggle-icon::before { top: -6px; }
.nav-toggle-icon::after { top: 4px; }

.site-nav {
  display: block;
}

.header-nav {
  display: flex;
  align-items: center;
  gap: 0.2rem;
  list-style: none;
  margin: 0;
  padding: 0;
}

.header-nav li a {
  display: block;
  padding: 0.45rem 0.7rem;
  color: #cbd5e1;
  font-weight: 600;
  font-size: 0.88rem;
  white-space: nowrap;
  border-radius: var(--radius-sm);
  transition: all 0.15s ease;
}

.header-nav li a:hover {
  color: #fff;
  background: rgba(255, 255, 255, 0.08);
  text-decoration: none;
}

.btn-header-order {
  background: linear-gradient(135deg, #10b981, #059669) !important;
  color: #fff !important;
  font-weight: 700 !important;
  padding: 0.45rem 0.95rem !important;
  border-radius: var(--radius-sm);
  box-shadow: 0 4px 12px rgba(16, 185, 129, 0.35);
}

.btn-header-order:hover {
  box-shadow: 0 6px 16px rgba(16, 185, 129, 0.5);
  transform: translateY(-1px);
}

@media (max-width: 992px) {
  .nav-toggle-btn {
    display: block;
  }
  .site-nav {
    display: none;
    position: absolute;
    top: 70px;
    left: 0;
    right: 0;
    background: #0f172a;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
    box-shadow: 0 15px 30px rgba(0, 0, 0, 0.5);
    padding: 1rem 1.25rem;
  }
  .header-nav {
    flex-direction: column;
    align-items: stretch;
    gap: 0.35rem;
  }
  #nav-toggle:checked ~ .site-nav {
    display: block;
  }
}

/* ==========================================================================
   Hero Showcase Section (Micro Shure MV88 Focused)
   ========================================================================== */
.hero-product-section {
  background: linear-gradient(180deg, #090d16 0%, #0f172a 100%);
  color: #fff;
  padding: 3.5rem 0 4rem 0;
  position: relative;
  overflow: hidden;
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
}

.hero-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 2.5rem;
  align-items: center;
}

@media (min-width: 992px) {
  .hero-grid {
    grid-template-columns: 1.1fr 0.9fr;
  }
}

.hero-badge-pill {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  background: rgba(16, 185, 129, 0.15);
  border: 1px solid rgba(16, 185, 129, 0.4);
  color: #34d399;
  font-size: 0.82rem;
  font-weight: 700;
  padding: 0.35rem 0.85rem;
  border-radius: var(--radius-full);
  margin-bottom: 1.25rem;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.hero-h1 {
  font-size: 2.5rem;
  font-weight: 800;
  line-height: 1.2;
  margin-bottom: 1.2rem;
  color: #ffffff;
  letter-spacing: -0.5px;
}

.hero-h1 .highlight {
  background: linear-gradient(135deg, #10b981 0%, #38bdf8 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero-desc {
  font-size: 1.1rem;
  color: #94a3b8;
  line-height: 1.7;
  margin-bottom: 1.75rem;
}

.hero-rating-box {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  margin-bottom: 1.75rem;
}

.stars {
  color: var(--gold);
  font-size: 1.1rem;
  letter-spacing: 2px;
}

.rating-score {
  font-weight: 700;
  color: #fff;
}

.rating-count {
  color: var(--text-light);
  font-size: 0.88rem;
}

.hero-cta-group {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  align-items: center;
}

.btn-cta-buy {
  background: linear-gradient(135deg, #10b981, #059669);
  color: #fff;
  font-weight: 700;
  font-size: 1.05rem;
  padding: 0.85rem 1.8rem;
  border-radius: var(--radius-sm);
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  box-shadow: 0 4px 20px rgba(16, 185, 129, 0.4);
}

.btn-cta-buy:hover {
  color: #fff;
  text-decoration: none;
  transform: translateY(-2px);
  box-shadow: 0 6px 25px rgba(16, 185, 129, 0.55);
}

.btn-cta-outline {
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid rgba(255, 255, 255, 0.2);
  color: #e2e8f0;
  font-weight: 600;
  font-size: 1.05rem;
  padding: 0.85rem 1.6rem;
  border-radius: var(--radius-sm);
}

.btn-cta-outline:hover {
  background: rgba(255, 255, 255, 0.12);
  color: #fff;
  text-decoration: none;
}

.hero-media-wrapper {
  position: relative;
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: 0 20px 40px rgba(0, 0, 0, 0.6);
  border: 1px solid rgba(255, 255, 255, 0.12);
}

.hero-media-wrapper img {
  width: 100%;
  height: auto;
  display: block;
}

.hero-media-badge {
  position: absolute;
  bottom: 1rem;
  left: 1rem;
  background: rgba(15, 23, 42, 0.85);
  backdrop-filter: blur(8px);
  border: 1px solid rgba(255, 255, 255, 0.15);
  padding: 0.5rem 0.9rem;
  border-radius: var(--radius-sm);
  font-size: 0.82rem;
  color: #38bdf8;
  font-weight: 600;
}

/* ==========================================================================
   Trust Bar & Guarantee
   ========================================================================== */
.trust-bar {
  background: #ffffff;
  border-bottom: 1px solid var(--border-light);
  padding: 1.25rem 0;
  box-shadow: var(--shadow-sm);
}

.trust-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 1.5rem;
}

.trust-item {
  display: flex;
  align-items: center;
  gap: 0.85rem;
}

.trust-icon {
  width: 44px;
  height: 44px;
  border-radius: var(--radius-sm);
  background: rgba(16, 185, 129, 0.1);
  color: var(--accent);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.3rem;
  flex-shrink: 0;
}

.trust-title {
  font-weight: 700;
  font-size: 0.95rem;
  color: var(--text-main);
  margin-bottom: 0.15rem;
}

.trust-desc {
  font-size: 0.82rem;
  color: var(--text-muted);
  line-height: 1.3;
}

/* ==========================================================================
   Product Showcase & Comparison
   ========================================================================== */
.section-wrapper {
  padding: 3.5rem 0;
}

.section-header {
  text-align: center;
  max-width: 800px;
  margin: 0 auto 2.5rem auto;
}

.section-label {
  color: var(--accent);
  font-size: 0.85rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 1px;
  margin-bottom: 0.5rem;
}

.section-title {
  font-size: 2rem;
  font-weight: 800;
  color: var(--text-main);
  line-height: 1.3;
}

.section-subtitle {
  color: var(--text-muted);
  font-size: 1.05rem;
  margin-top: 0.5rem;
}

/* Pure CSS Tab Component (Zero JavaScript!) */
.tabs-container {
  background: var(--bg-surface);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-sm);
  overflow: hidden;
  margin: 2.5rem 0;
}

.tab-nav {
  display: flex;
  background: #f1f5f9;
  border-bottom: 1px solid var(--border-light);
  overflow-x: auto;
}

.tab-radio {
  display: none;
}

.tab-label {
  padding: 1rem 1.5rem;
  font-weight: 700;
  font-size: 0.95rem;
  color: var(--text-muted);
  cursor: pointer;
  border-bottom: 3px solid transparent;
  white-space: nowrap;
  transition: all 0.15s ease;
}

.tab-label:hover {
  color: var(--accent-blue);
}

#tab-1:checked ~ .tab-nav label[for="tab-1"],
#tab-2:checked ~ .tab-nav label[for="tab-2"],
#tab-3:checked ~ .tab-nav label[for="tab-3"],
#tab-4:checked ~ .tab-nav label[for="tab-4"] {
  color: var(--text-main);
  background: #ffffff;
  border-bottom-color: var(--accent);
}

.tab-content {
  display: none;
  padding: 2rem;
}

#tab-1:checked ~ .tab-panels #panel-1,
#tab-2:checked ~ .tab-panels #panel-2,
#tab-3:checked ~ .tab-panels #panel-3,
#tab-4:checked ~ .tab-panels #panel-4 {
  display: block;
}

/* Specifications Table */
.spec-table {
  width: 100%;
  border-collapse: collapse;
  margin: 1.5rem 0;
}

.spec-table th, .spec-table td {
  padding: 0.85rem 1.25rem;
  border: 1px solid var(--border-light);
  font-size: 0.95rem;
}

.spec-table th {
  background: #f8fafc;
  color: var(--text-main);
  font-weight: 700;
  width: 35%;
}

.spec-table tr:hover td {
  background: #f8fafc;
}

/* Comparison Matrix */
.matrix-table {
  width: 100%;
  border-collapse: collapse;
  margin: 2rem 0;
  background: #fff;
  border-radius: var(--radius-sm);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
}

.matrix-table th, .matrix-table td {
  padding: 1rem 1.2rem;
  border: 1px solid var(--border-light);
  text-align: center;
}

.matrix-table th:first-child, .matrix-table td:first-child {
  text-align: left;
  font-weight: 600;
}

.matrix-table th {
  background: #0f172a;
  color: #fff;
  font-size: 0.95rem;
}

.matrix-table th.highlight-col {
  background: #10b981;
  color: #fff;
}

.badge-winner {
  background: #dcfce7;
  color: #166534;
  font-weight: 700;
  font-size: 0.78rem;
  padding: 0.2rem 0.6rem;
  border-radius: var(--radius-full);
  display: inline-block;
}

/* Product Cards Grid */
.product-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 1.75rem;
  margin: 2rem 0;
}

.product-card {
  background: var(--bg-surface);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-md);
  padding: 1.5rem;
  box-shadow: var(--shadow-sm);
  display: flex;
  flex-direction: column;
  transition: all 0.2s ease;
}

.product-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
  border-color: #cbd5e1;
}

.product-thumb {
  border-radius: var(--radius-sm);
  overflow: hidden;
  margin-bottom: 1.25rem;
  background: #f1f5f9;
}

.product-title {
  font-size: 1.2rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
}

.product-price {
  font-size: 1.35rem;
  font-weight: 800;
  color: #e11d48;
  margin-bottom: 0.75rem;
}

.product-price del {
  font-size: 0.95rem;
  color: var(--text-light);
  margin-left: 0.5rem;
  font-weight: 500;
}

.product-features-list {
  list-style: none;
  padding: 0;
  margin: 0 0 1.25rem 0;
  font-size: 0.88rem;
  color: var(--text-muted);
}

.product-features-list li {
  padding: 0.3rem 0;
  border-bottom: 1px dashed var(--border-light);
}

/* ==========================================================================
   Content Layout & Semantic Article Elements
   ========================================================================== */
.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 1.25rem;
}

.content-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 2.5rem;
  margin: 2rem 0;
}

@media (min-width: 992px) {
  .content-grid {
    grid-template-columns: minmax(0, 1fr) 340px;
  }
}

.post-article {
  background: var(--bg-surface);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-md);
  padding: 2.25rem;
  box-shadow: var(--shadow-sm);
}

@media (max-width: 768px) {
  .post-article {
    padding: 1.25rem;
  }
}

.post-header {
  border-bottom: 1px solid var(--border-light);
  padding-bottom: 1.25rem;
  margin-bottom: 1.75rem;
}

.post-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  font-size: 0.88rem;
  color: var(--text-muted);
  margin-top: 0.75rem;
}

/* Breadcrumbs (SEO BreadcrumbList) */
.breadcrumbs {
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-bottom: 1.5rem;
  padding: 0.65rem 1rem;
  background: #ffffff;
  border: 1px solid var(--border-light);
  border-radius: var(--radius-sm);
}

.breadcrumbs a {
  color: var(--accent-blue);
  font-weight: 500;
}

.breadcrumbs .separator {
  margin: 0 0.4rem;
  color: var(--text-light);
}

/* Table of Contents (Pure PHP / CSS, Zero JS) */
.toc-box {
  background: #f8fafc;
  border: 1px solid #cbd5e1;
  border-left: 4px solid var(--accent);
  border-radius: var(--radius-sm);
  padding: 1.25rem 1.5rem;
  margin: 2rem 0;
}

.toc-title {
  font-weight: 800;
  font-size: 1.1rem;
  margin-bottom: 0.75rem;
  color: var(--text-main);
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.toc-list {
  list-style: none;
  padding-left: 0;
  margin: 0;
  font-size: 0.95rem;
}

.toc-list li {
  margin-bottom: 0.4rem;
}

.toc-list li a {
  color: var(--text-main);
}

.toc-list li a:hover {
  color: var(--accent-blue);
}

.toc-list li.toc-h3 {
  padding-left: 1.5rem;
  font-size: 0.9rem;
  color: var(--text-muted);
}

/* Author Box (E-E-A-T Signal) */
.author-box {
  display: flex;
  gap: 1.25rem;
  background: #f8fafc;
  border: 1px solid var(--border-light);
  border-radius: var(--radius-md);
  padding: 1.5rem;
  margin-top: 2.5rem;
  align-items: center;
}

.author-avatar {
  width: 64px;
  height: 64px;
  border-radius: 50%;
  background: var(--primary);
  color: #fff;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  font-weight: 800;
  flex-shrink: 0;
  box-shadow: var(--shadow-sm);
}

.author-info h4 {
  font-size: 1.1rem;
  margin-bottom: 0.25rem;
}

.author-info p {
  margin: 0;
  font-size: 0.88rem;
  color: var(--text-muted);
}

/* ==========================================================================
   Pure CSS Accordions / FAQ (Zero JS, 100% crawlable)
   ========================================================================== */
.faq-section {
  margin: 2.5rem 0;
}

details.faq-item {
  background: var(--bg-surface);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-sm);
  margin-bottom: 0.85rem;
  overflow: hidden;
  transition: all 0.2s ease;
}

details.faq-item[open] {
  border-color: var(--accent);
  box-shadow: var(--shadow-sm);
}

summary.faq-question {
  padding: 1.1rem 1.25rem;
  font-weight: 700;
  font-size: 1.05rem;
  cursor: pointer;
  list-style: none;
  display: flex;
  justify-content: space-between;
  align-items: center;
  color: var(--text-main);
  user-select: none;
}

summary.faq-question::-webkit-details-marker {
  display: none;
}

summary.faq-question::after {
  content: '+';
  font-size: 1.4rem;
  font-weight: 600;
  color: var(--accent);
  line-height: 1;
}

details.faq-item[open] summary.faq-question::after {
  content: '−';
  color: #e11d48;
}

.faq-answer {
  padding: 0 1.25rem 1.25rem 1.25rem;
  color: #475569;
  font-size: 0.95rem;
  line-height: 1.7;
  border-top: 1px solid #f1f5f9;
  padding-top: 1rem;
}

/* ==========================================================================
   Sidebar & Widgets
   ========================================================================== */
.site-sidebar {
  display: flex;
  flex-direction: column;
  gap: 1.75rem;
}

.widget {
  background: var(--bg-surface);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-md);
  padding: 1.5rem;
  box-shadow: var(--shadow-sm);
}

.widget-title {
  font-size: 1.15rem;
  font-weight: 800;
  color: var(--text-main);
  margin-bottom: 1rem;
  padding-bottom: 0.5rem;
  border-bottom: 2px solid var(--accent);
}

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

.widget ul li {
  padding: 0.5rem 0;
  border-bottom: 1px solid #f1f5f9;
  font-size: 0.92rem;
}

.widget ul li:last-child {
  border-bottom: none;
}

.widget ul li a {
  color: var(--text-main);
}

.widget ul li a:hover {
  color: var(--accent-blue);
}

/* ==========================================================================
   Footer
   ========================================================================== */
.site-footer {
  background: #090d16;
  color: #94a3b8;
  padding: 4rem 0 2rem 0;
  margin-top: auto;
  border-top: 1px solid rgba(255, 255, 255, 0.08);
}

.footer-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 2.5rem;
  margin-bottom: 3rem;
}

.footer-widget h4 {
  color: #fff;
  font-size: 1.15rem;
  margin-bottom: 1.25rem;
  font-weight: 700;
}

.footer-widget p {
  color: #94a3b8;
  font-size: 0.9rem;
  line-height: 1.65;
}

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

.footer-widget ul li {
  margin-bottom: 0.65rem;
}

.footer-widget ul li a {
  color: #cbd5e1;
  font-size: 0.92rem;
}

.footer-widget ul li a:hover {
  color: #fff;
}

.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  padding-top: 2rem;
  text-align: center;
  font-size: 0.85rem;
  color: #64748b;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.75rem 1.5rem;
  font-weight: 700;
  font-size: 0.98rem;
  border-radius: var(--radius-sm);
  cursor: pointer;
  border: none;
  transition: all 0.2s ease;
}

.btn-primary {
  background: var(--accent);
  color: #fff;
}

.btn-primary:hover {
  background: var(--accent-hover);
  color: #fff;
  text-decoration: none;
}

.btn-secondary {
  background: #f1f5f9;
  color: var(--text-main);
  border: 1px solid var(--border-light);
}

.btn-secondary:hover {
  background: #e2e8f0;
  text-decoration: none;
}