/* ==========================================================================
   PropTechStack Design System - Dark & Light Themes (Linear / Vercel Aesthetic)
   ========================================================================== */

:root {
  /* Brand Accents */
  --primary: #38bdf8;
  --primary-hover: #0284c7;
  --accent: #10b981;
  --accent-hover: #059669;
  --amber: #f59e0b;
  --danger: #ef4444;
  
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 18px;
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --transition: all 0.2s cubic-bezier(0.16, 1, 0.3, 1);

  /* DARK THEME BY DEFAULT (High-End Dark SaaS) */
  --bg: #090d16;
  --surface: #111827;
  --surface-alt: #1a2234;
  --surface-card: #111a2e;
  --border: #1f293d;
  --border-focus: #38bdf8;
  --border-subtle: rgba(255, 255, 255, 0.08);

  --text-main: #f8fafc;
  --text-body: #cbd5e1;
  --text-muted: #94a3b8;
  --text-light: #64748b;

  --header-bg: rgba(9, 13, 22, 0.9);
  --header-border: rgba(255, 255, 255, 0.08);

  --card-shadow: 0 4px 20px -2px rgba(0, 0, 0, 0.5), 0 0 1px 1px rgba(255, 255, 255, 0.07);
  --card-shadow-hover: 0 16px 36px -4px rgba(0, 0, 0, 0.7), 0 0 1px 1px rgba(56, 189, 248, 0.4);

  --quick-verdict-bg: #062817;
  --quick-verdict-border: #166534;
  --quick-verdict-title: #4ade80;
  --quick-verdict-text: #bbf7d0;

  --pros-bg: rgba(16, 185, 129, 0.08);
  --pros-border: rgba(16, 185, 129, 0.25);
  --pros-text: #6ee7b7;

  --cons-bg: rgba(239, 68, 68, 0.08);
  --cons-border: rgba(239, 68, 68, 0.25);
  --cons-text: #fca5a5;

  --table-header: #141e33;
  --table-hover: #17233b;
  --footer-bg: #050811;
  --footer-border: #172033;
}

/* LIGHT THEME OVERRIDES */
body.light-theme {
  --bg: #f8fafc;
  --surface: #ffffff;
  --surface-alt: #f1f5f9;
  --surface-card: #ffffff;
  --border: #e2e8f0;
  --border-focus: #0284c7;
  --border-subtle: rgba(226, 232, 240, 0.8);

  --text-main: #0f172a;
  --text-body: #334155;
  --text-muted: #64748b;
  --text-light: #94a3b8;

  --header-bg: rgba(255, 255, 255, 0.92);
  --header-border: #e2e8f0;

  --card-shadow: 0 4px 20px -2px rgba(15, 23, 42, 0.06), 0 0 1px 1px rgba(226, 232, 240, 0.8);
  --card-shadow-hover: 0 14px 30px -4px rgba(15, 23, 42, 0.12), 0 0 1px 1px rgba(2, 132, 199, 0.25);

  --quick-verdict-bg: #f0fdf4;
  --quick-verdict-border: #bbf7d0;
  --quick-verdict-title: #166534;
  --quick-verdict-text: #14532d;

  --pros-bg: #f0fdf4;
  --pros-border: #bbf7d0;
  --pros-text: #14532d;

  --cons-bg: #fef2f2;
  --cons-border: #fecaca;
  --cons-text: #7f1d1d;

  --table-header: #f8fafc;
  --table-hover: #f8fafc;
  --footer-bg: #0f172a;
  --footer-border: #1e293b;
}

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

body {
  font-family: var(--font-sans);
  background-color: var(--bg);
  color: var(--text-body);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  letter-spacing: -0.01em;
  transition: background-color 0.25s ease, color 0.25s ease;
}

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

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

.container {
  max-width: 1220px;
  margin: 0 auto;
  padding: 0 24px;
}

/* Site Header */
.site-header {
  background: var(--header-bg);
  border-bottom: 1px solid var(--header-border);
  position: sticky;
  top: 0;
  z-index: 100;
  backdrop-filter: blur(14px);
  transition: var(--transition);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
}

.brand-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 1.35rem;
  font-weight: 800;
  color: var(--text-main);
  letter-spacing: -0.02em;
}

.logo-badge {
  background: linear-gradient(135deg, #0284c7 0%, #38bdf8 100%);
  color: #fff;
  width: 36px;
  height: 36px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-sm);
  font-weight: 800;
  font-size: 1.15rem;
  box-shadow: 0 0 14px rgba(56, 189, 248, 0.4);
}

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

.main-nav {
  display: flex;
  align-items: center;
  gap: 22px;
}

.nav-link {
  font-size: 0.92rem;
  font-weight: 600;
  color: var(--text-body);
  transition: var(--transition);
}

.nav-link:hover, .nav-link.active {
  color: var(--primary);
}

.badge-tag {
  display: inline-block;
  font-size: 0.72rem;
  font-weight: 700;
  text-transform: uppercase;
  padding: 3px 9px;
  border-radius: 9999px;
  background: rgba(56, 189, 248, 0.15);
  color: var(--primary);
  border: 1px solid rgba(56, 189, 248, 0.25);
  letter-spacing: 0.05em;
}

/* Header Action & Theme Toggle */
.header-actions {
  display: flex;
  align-items: center;
  gap: 12px;
}

.theme-toggle-btn {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  background: var(--surface-alt);
  border: 1px solid var(--border);
  color: var(--text-main);
  padding: 7px 14px;
  border-radius: var(--radius-sm);
  font-size: 0.85rem;
  font-weight: 600;
  cursor: pointer;
  transition: var(--transition);
}

.theme-toggle-btn:hover {
  border-color: var(--border-focus);
  background: var(--surface-card);
  color: var(--primary);
  box-shadow: 0 0 10px rgba(56, 189, 248, 0.2);
}

.theme-icon {
  display: flex;
  align-items: center;
}

/* Hero Section */
.hero {
  padding: 60px 0 44px;
  text-align: center;
  background: radial-gradient(circle at 50% 0%, rgba(56, 189, 248, 0.08) 0%, transparent 70%);
  border-bottom: 1px solid var(--border);
}

.hero h1 {
  font-size: 2.75rem;
  font-weight: 900;
  letter-spacing: -0.03em;
  color: var(--text-main);
  line-height: 1.2;
  margin: 16px auto 14px;
  max-width: 880px;
}

.hero p {
  font-size: 1.15rem;
  color: var(--text-muted);
  max-width: 760px;
  margin: 0 auto 24px;
}

.hero-stats {
  display: flex;
  justify-content: center;
  gap: 36px;
  margin-top: 24px;
  font-size: 0.92rem;
  color: var(--text-muted);
}

.hero-stats span {
  font-weight: 800;
  color: var(--text-main);
}

/* Quick Verdict Box (Perplexity & AI Overviews) */
.quick-verdict-box {
  background: var(--quick-verdict-bg);
  border: 1px solid var(--quick-verdict-border);
  border-left: 5px solid var(--accent);
  border-radius: var(--radius-md);
  padding: 24px;
  margin: 32px 0;
  box-shadow: var(--card-shadow);
}

.quick-verdict-box h3 {
  color: var(--quick-verdict-title);
  font-size: 1.2rem;
  margin-bottom: 12px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.quick-verdict-box ul {
  list-style: none;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 12px;
}

.quick-verdict-box li {
  font-size: 0.95rem;
  color: var(--quick-verdict-text);
}

.quick-verdict-box li strong {
  color: var(--text-main);
}

/* Software Grid & Cards */
.software-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(350px, 1fr));
  gap: 24px;
  margin: 40px 0;
}

.software-card {
  background: var(--surface-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 26px;
  box-shadow: var(--card-shadow);
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  transition: var(--transition);
}

.software-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--card-shadow-hover);
  border-color: rgba(56, 189, 248, 0.4);
}

.card-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  margin-bottom: 14px;
}

.card-title-group h3 {
  font-size: 1.35rem;
  font-weight: 700;
  color: var(--text-main);
}

.card-title-group .category-sub {
  font-size: 0.85rem;
  color: var(--text-muted);
}

.rating-badge {
  background: rgba(245, 158, 11, 0.15);
  color: #fbbf24;
  font-weight: 800;
  font-size: 0.9rem;
  padding: 4px 10px;
  border-radius: var(--radius-sm);
  border: 1px solid rgba(245, 158, 11, 0.3);
  display: flex;
  align-items: center;
  gap: 4px;
}

.card-body p {
  font-size: 0.95rem;
  color: var(--text-body);
  margin-bottom: 16px;
}

.feature-pills {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-bottom: 20px;
}

.pill {
  font-size: 0.8rem;
  background: var(--surface-alt);
  color: var(--text-body);
  border: 1px solid var(--border-subtle);
  padding: 3px 9px;
  border-radius: var(--radius-sm);
}

.pricing-row {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  padding-top: 16px;
  border-top: 1px solid var(--border);
  margin-bottom: 16px;
}

.pricing-row .price {
  font-size: 1.25rem;
  font-weight: 800;
  color: var(--text-main);
}

.pricing-row .price-sub {
  font-size: 0.8rem;
  color: var(--text-muted);
}

.card-actions {
  display: flex;
  gap: 10px;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-weight: 600;
  font-size: 0.95rem;
  padding: 10px 18px;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: var(--transition);
  text-align: center;
}

.btn-primary {
  background: linear-gradient(135deg, #10b981 0%, #059669 100%);
  color: #ffffff;
  border: 1px solid transparent;
  box-shadow: 0 4px 14px rgba(16, 185, 129, 0.3);
}

.btn-primary:hover {
  background: linear-gradient(135deg, #059669 0%, #047857 100%);
  color: #ffffff;
  box-shadow: 0 6px 18px rgba(16, 185, 129, 0.45);
}

.btn-outline {
  background: var(--surface-alt);
  color: var(--text-main);
  border: 1px solid var(--border);
}

.btn-outline:hover {
  background: var(--surface);
  border-color: var(--border-focus);
  color: var(--primary);
}

.btn-block {
  width: 100%;
}

/* Comparison Tables */
.table-wrapper {
  overflow-x: auto;
  background: var(--surface-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  margin: 32px 0;
  box-shadow: var(--card-shadow);
}

.comparison-table {
  width: 100%;
  border-collapse: collapse;
  text-align: left;
  font-size: 0.92rem;
}

.comparison-table th {
  background: var(--table-header);
  padding: 15px 18px;
  font-weight: 700;
  color: var(--text-main);
  border-bottom: 2px solid var(--border);
}

.comparison-table td {
  padding: 15px 18px;
  border-bottom: 1px solid var(--border);
  color: var(--text-body);
  vertical-align: middle;
}

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

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

.check {
  color: var(--accent);
  font-weight: bold;
}

.cross {
  color: var(--danger);
  font-weight: bold;
}

/* Pros / Cons Component */
.pros-cons-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
  margin: 28px 0;
}

.pros-box, .cons-box {
  padding: 22px;
  border-radius: var(--radius-md);
}

.pros-box {
  background: var(--pros-bg);
  border: 1px solid var(--pros-border);
}

.pros-box h4 {
  color: var(--accent);
  margin-bottom: 12px;
}

.cons-box {
  background: var(--cons-bg);
  border: 1px solid var(--cons-border);
}

.cons-box h4 {
  color: var(--danger);
  margin-bottom: 12px;
}

.pros-box ul, .cons-box ul {
  padding-left: 20px;
  font-size: 0.92rem;
}

.pros-box li { color: var(--pros-text); margin-bottom: 6px; }
.cons-box li { color: var(--cons-text); margin-bottom: 6px; }

/* Article Container */
.article-container {
  max-width: 880px;
  margin: 40px auto;
  background: var(--surface-card);
  padding: 48px;
  border-radius: var(--radius-lg);
  border: 1px solid var(--border);
  box-shadow: var(--card-shadow);
}

.article-header {
  margin-bottom: 32px;
  border-bottom: 1px solid var(--border);
  padding-bottom: 24px;
}

.breadcrumbs {
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-bottom: 14px;
}

.article-title {
  font-size: 2.3rem;
  font-weight: 800;
  color: var(--text-main);
  line-height: 1.25;
  margin-bottom: 12px;
}

.article-meta {
  font-size: 0.88rem;
  color: var(--text-muted);
}

.article-content h2 {
  font-size: 1.65rem;
  font-weight: 800;
  color: var(--text-main);
  margin: 36px 0 16px;
  border-bottom: 1px solid var(--border);
  padding-bottom: 8px;
}

.article-content h3 {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--text-main);
  margin: 24px 0 12px;
}

.article-content p {
  font-size: 1.05rem;
  line-height: 1.75;
  color: var(--text-body);
  margin-bottom: 18px;
}

.article-content ul, .article-content ol {
  margin: 16px 0 24px 24px;
  font-size: 1.02rem;
  color: var(--text-body);
}

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

.callout-box {
  background: var(--surface-alt);
  border-left: 4px solid var(--primary);
  padding: 20px 24px;
  border-radius: var(--radius-sm);
  margin: 24px 0;
  font-size: 0.98rem;
  color: var(--text-body);
  border-top: 1px solid var(--border-subtle);
  border-right: 1px solid var(--border-subtle);
  border-bottom: 1px solid var(--border-subtle);
}

/* Site Footer */
.site-footer {
  background: var(--footer-bg);
  color: var(--text-muted);
  padding: 60px 0 32px;
  margin-top: 80px;
  border-top: 1px solid var(--footer-border);
  font-size: 0.9rem;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 40px;
  margin-bottom: 48px;
}

.footer-col h4 {
  color: var(--text-main);
  font-size: 1rem;
  font-weight: 700;
  margin-bottom: 18px;
}

.footer-links {
  list-style: none;
}

.footer-links li {
  margin-bottom: 10px;
}

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

.footer-links a:hover {
  color: var(--text-main);
}

.footer-bottom {
  border-top: 1px solid var(--footer-border);
  padding-top: 28px;
  display: flex;
  flex-direction: column;
  gap: 16px;
  font-size: 0.8rem;
  color: var(--text-light);
  text-align: center;
}

.ftc-notice {
  font-size: 0.78rem;
  color: var(--text-light);
  line-height: 1.5;
  max-width: 920px;
  margin: 0 auto;
}

@media (max-width: 768px) {
  .header-inner {
    flex-direction: column;
    height: auto;
    padding: 16px 0;
    gap: 12px;
  }
  .main-nav {
    flex-wrap: wrap;
    justify-content: center;
    gap: 14px;
  }
  .hero h1 {
    font-size: 2rem;
  }
  .software-grid {
    grid-template-columns: 1fr;
  }
  .pros-cons-grid {
    grid-template-columns: 1fr;
  }
  .article-container {
    padding: 24px;
    margin: 20px auto;
  }
  .footer-grid {
    grid-template-columns: 1fr;
    gap: 28px;
  }
}