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

html {
  scroll-behavior: smooth;
}

/* Color Variables - Dark Mode (Default) */
html[data-theme="dark"] {
  --bg-primary: #0b0f19;
  --bg-secondary: #161b26;
  --bg-tertiary: #202736;
  --border-color: #242e42;
  --input-border: #2e3b54;
  --accent: #00A868;
  --accent-hover: #00935a;
  --accent-light: rgba(0, 168, 104, 0.15);
  --text-primary: #f3f4f6;
  --text-secondary: #9ca3af;
  --text-muted: #6b7280;
  --shadow-sm: rgba(0, 0, 0, 0.2);
  --shadow-md: rgba(0, 0, 0, 0.35);
  --card-border-glow: rgba(0, 168, 104, 0.05);
}

/* Color Variables - Light Mode */
html[data-theme="light"] {
  --bg-primary: #f8fafc;
  --bg-secondary: #ffffff;
  --bg-tertiary: #f1f5f9;
  --border-color: #e2e8f0;
  --input-border: #cbd5e1;
  --accent: #00A868;
  --accent-hover: #00935a;
  --accent-light: rgba(0, 168, 104, 0.1);
  --text-primary: #0f172a;
  --text-secondary: #475569;
  --text-muted: #64748b;
  --shadow-sm: rgba(0, 0, 0, 0.03);
  --shadow-md: rgba(0, 0, 0, 0.08);
  --card-border-glow: transparent;
}

body {
  font-family: 'Plus Jakarta Sans', sans-serif;
  background-color: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.6;
  transition: background-color 0.3s ease, color 0.3s ease;
  min-height: 100vh;
}

/* Headings */
h1, h2, h3, h4, h5, h6 {
  font-family: 'Outfit', sans-serif;
  font-weight: 600;
  color: var(--text-primary);
  line-height: 1.3;
}

/* Header Styles */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background-color: rgba(var(--bg-secondary), 0.85);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border-color);
  transition: background-color 0.3s ease, border-color 0.3s ease;
}

/* We use helper class to handle rgba backdrop background fallback */
html[data-theme="dark"] .site-header {
  background-color: rgba(22, 27, 38, 0.85);
}
html[data-theme="light"] .site-header {
  background-color: rgba(255, 255, 255, 0.85);
}

.header-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 16px 24px;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.header-logo-group {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.back-link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 13px;
  font-weight: 500;
  transition: color 0.2s;
}

.back-link:hover {
  color: var(--accent);
}

.brand-title-wrap {
  display: flex;
  align-items: center;
  gap: 8px;
}

.brand-title {
  font-size: 20px;
  font-weight: 700;
}

.badge {
  background-color: var(--accent-light);
  color: var(--accent);
  padding: 2px 8px;
  border-radius: 20px;
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.5px;
  text-transform: uppercase;
  border: 1px solid var(--accent);
}

.quick-nav {
  display: flex;
  gap: 20px;
}

.nav-item {
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 14px;
  font-weight: 500;
  transition: color 0.2s;
}

.nav-item:hover {
  color: var(--accent);
}

/* Theme Toggle Button */
.theme-toggle-btn {
  background: none;
  border: 1px solid var(--border-color);
  color: var(--text-secondary);
  cursor: pointer;
  padding: 8px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all 0.2s ease;
}

.theme-toggle-btn:hover {
  color: var(--accent);
  border-color: var(--accent);
  background-color: var(--bg-tertiary);
}

.theme-toggle-btn svg {
  width: 20px;
  height: 20px;
}

/* Show/hide correct icon based on active theme */
html[data-theme="dark"] .theme-toggle-btn .sun-icon {
  display: block;
}
html[data-theme="dark"] .theme-toggle-btn .moon-icon {
  display: none;
}
html[data-theme="light"] .theme-toggle-btn .sun-icon {
  display: none;
}
html[data-theme="light"] .theme-toggle-btn .moon-icon {
  display: block;
}

/* Main Layout Wrapper */
.main-wrapper {
  max-width: 1200px;
  margin: 0 auto;
  padding: 40px 24px;
}

/* Hero Section */
.hero-section {
  text-align: center;
  margin-bottom: 32px;
}

.hero-title {
  font-size: 36px;
  margin-bottom: 12px;
  letter-spacing: -0.5px;
}

.hero-subtitle {
  color: var(--text-secondary);
  max-width: 700px;
  margin: 0 auto;
  font-size: 16px;
}

.adsense-wrap {
  width: 100%;
  margin: 24px 0;
  text-align: center;
  background-color: var(--bg-secondary);
  border: 1px dashed var(--border-color);
  border-radius: 12px;
  padding: 15px;
  min-height: 90px;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  position: relative;
  transition: all 0.3s ease;
}

/* Hide ad container layout properties if an ad loads successfully */
.adsense-wrap:has(ins[data-ad-status="filled"]) {
  background-color: transparent;
  border: none;
  padding: 0;
  min-height: auto;
}

/* Hide the placeholder text when an ad is active */
.adsense-wrap:has(ins[data-ad-status="filled"]) .ad-placeholder-text {
  display: none;
}

.ad-placeholder-text {
  font-family: 'Outfit', sans-serif;
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 2px;
  color: var(--text-muted);
  text-transform: uppercase;
  user-select: none;
}

/* Hide any residual dots/characters rendered by the empty ins element */
.adsense-wrap ins {
  font-size: 0;
  color: transparent;
}

/* Tabs Switcher */
.tabs-container {
  display: flex;
  background-color: var(--bg-secondary);
  padding: 6px;
  border-radius: 14px;
  border: 1px solid var(--border-color);
  max-width: 420px;
  margin: 0 auto 32px auto;
  box-shadow: var(--shadow-sm);
}

.tab-btn {
  flex: 1;
  background: none;
  border: none;
  color: var(--text-secondary);
  padding: 12px 16px;
  font-family: 'Outfit', sans-serif;
  font-weight: 500;
  font-size: 15px;
  border-radius: 10px;
  cursor: pointer;
  transition: all 0.2s ease;
}

.tab-btn:hover {
  color: var(--text-primary);
}

.tab-btn.active {
  background-color: var(--accent);
  color: #ffffff;
  box-shadow: 0 4px 12px rgba(0, 168, 104, 0.25);
}

/* Panel management */
.panel-content {
  display: none;
}

.panel-content.active {
  display: block;
}

/* Calculator Grid */
.calc-grid {
  display: grid;
  grid-template-columns: 1.1fr 1.3fr;
  gap: 32px;
  align-items: start;
}

/* Cards Base */
.calc-card {
  background-color: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: 16px;
  padding: 30px;
  box-shadow: var(--shadow-md);
  box-shadow: var(--shadow-md), 0 0 40px var(--card-border-glow);
  transition: background-color 0.3s ease, border-color 0.3s ease;
}

.card-title {
  font-size: 20px;
  margin-bottom: 24px;
  border-bottom: 1px solid var(--border-color);
  padding-bottom: 12px;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

/* Form inputs & containers */
.form-group {
  margin-bottom: 20px;
  position: relative;
}

.form-group:last-child {
  margin-bottom: 0;
}

.form-group label {
  display: block;
  font-size: 14px;
  font-weight: 500;
  color: var(--text-secondary);
  margin-bottom: 8px;
}

.label-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 8px;
}

.label-row label {
  margin-bottom: 0;
}

/* Input container wrapper to incorporate visual prefix/suffix */
.input-container {
  display: flex;
  align-items: center;
  background-color: var(--bg-tertiary);
  border: 1px solid var(--input-border);
  border-radius: 10px;
  padding: 0 16px;
  height: 50px;
  transition: all 0.2s ease;
}

.input-container:focus-within {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-light);
}

.input-container input {
  flex: 1;
  width: 100%;
  height: 100%;
  background: transparent;
  border: none;
  outline: none;
  font-family: inherit;
  font-size: 16px;
  font-weight: 600;
  color: var(--text-primary);
  text-align: right;
  padding: 0;
}

.input-container input::placeholder {
  color: var(--text-muted);
}

.input-prefix {
  font-size: 16px;
  font-weight: 600;
  color: var(--text-secondary);
  margin-right: 8px;
  user-select: none;
}

.input-suffix {
  font-size: 14px;
  font-weight: 500;
  color: var(--text-secondary);
  margin-left: 8px;
  user-select: none;
}

/* Disabled input state */
.disabled-input {
  background-color: rgba(36, 46, 66, 0.2);
  border-color: var(--border-color);
}
.disabled-input input {
  color: var(--text-secondary);
  cursor: not-allowed;
}

/* Date input specific overrides */
.date-input {
  text-align: left !important;
  color-scheme: dark;
}
html[data-theme="light"] .date-input {
  color-scheme: light;
}

/* Toggle switches inside forms */
.toggle-switch-group {
  display: inline-flex;
  background-color: var(--bg-tertiary);
  padding: 3px;
  border-radius: 8px;
  border: 1px solid var(--input-border);
}

.toggle-btn {
  background: none;
  border: none;
  color: var(--text-secondary);
  font-size: 12px;
  font-weight: 600;
  padding: 4px 10px;
  border-radius: 6px;
  cursor: pointer;
  transition: all 0.15s ease;
}

.toggle-btn.active {
  background-color: var(--accent);
  color: #ffffff;
}

.full-width-toggle {
  display: flex;
  width: 100%;
  padding: 4px;
  border-radius: 10px;
}

.full-width-toggle .toggle-btn {
  flex: 1;
  padding: 10px;
  font-size: 14px;
}

/* Custom Checkbox */
.checkbox-group {
  margin-top: 24px;
}

.custom-checkbox-container {
  display: flex;
  align-items: center;
  position: relative;
  padding-left: 32px;
  cursor: pointer;
  user-select: none;
  font-size: 14px;
  font-weight: 500;
  color: var(--text-secondary);
}

.custom-checkbox-container input {
  position: absolute;
  opacity: 0;
  cursor: pointer;
  height: 0;
  width: 0;
}

.checkmark {
  position: absolute;
  top: 50%;
  left: 0;
  transform: translateY(-50%);
  height: 20px;
  width: 20px;
  background-color: var(--bg-tertiary);
  border: 1px solid var(--input-border);
  border-radius: 6px;
  transition: all 0.2s ease;
}

.custom-checkbox-container:hover input ~ .checkmark {
  border-color: var(--accent);
}

.custom-checkbox-container input:checked ~ .checkmark {
  background-color: var(--accent);
  border-color: var(--accent);
}

.checkmark::after {
  content: "";
  position: absolute;
  display: none;
}

.custom-checkbox-container input:checked ~ .checkmark::after {
  display: block;
}

.custom-checkbox-container .checkmark::after {
  left: 6px;
  top: 2px;
  width: 5px;
  height: 10px;
  border: solid white;
  border-width: 0 2px 2px 0;
  transform: rotate(45deg);
}

/* Helpers & Info Messages */
.input-helper-text {
  font-size: 12px;
  color: var(--text-muted);
  margin-top: 6px;
  font-weight: 500;
}

.input-helper-text.error-msg {
  color: var(--accent); /* Emerald default */
}

.input-helper-text.invalid {
  color: #ef4444; /* Standard soft red error */
}

/* Results Display styles */
.results-overview {
  background-color: var(--bg-tertiary);
  border-radius: 12px;
  padding: 20px;
  margin-bottom: 24px;
  text-align: center;
  border: 1px solid var(--border-color);
}

.result-highlight {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.result-label {
  font-size: 13px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  color: var(--text-secondary);
}

.result-val {
  font-family: 'Outfit', sans-serif;
  font-size: 20px;
  font-weight: 700;
  color: var(--text-primary);
}

.result-val.highlight-accent {
  font-size: 36px;
  color: var(--accent);
  letter-spacing: -0.5px;
}

.results-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
  margin-bottom: 30px;
}

.result-sub-item {
  border: 1px solid var(--border-color);
  background-color: rgba(var(--bg-tertiary), 0.3);
  padding: 16px;
  border-radius: 12px;
  display: flex;
  flex-direction: column;
  gap: 4px;
}

/* Charts Containers */
.chart-wrapper {
  margin-top: 30px;
  padding-top: 24px;
  border-top: 1px solid var(--border-color);
  position: relative;
  width: 100%;
}

.chart-wrapper canvas {
  width: 100% !important;
  height: auto !important;
  max-height: 280px;
}

/* SEO Content & Article layout */
.seo-section {
  margin-top: 60px;
  border-top: 1px solid var(--border-color);
  padding-top: 48px;
}

.seo-article {
  max-width: 800px;
  margin: 0 auto 48px auto;
}

.seo-article h2 {
  font-size: 28px;
  margin-bottom: 18px;
}

.seo-article h3 {
  font-size: 20px;
  margin-top: 32px;
  margin-bottom: 14px;
}

.seo-article p {
  font-size: 15px;
  color: var(--text-secondary);
  margin-bottom: 20px;
}

.seo-article ul, .seo-article ol {
  margin-left: 20px;
  margin-bottom: 20px;
  color: var(--text-secondary);
  font-size: 15px;
}

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

/* Callout formulas */
.math-callout {
  background-color: var(--bg-secondary);
  border-left: 4px solid var(--accent);
  padding: 16px;
  border-radius: 0 10px 10px 0;
  margin: 20px 0;
  font-family: inherit;
  box-shadow: var(--shadow-sm);
}

.math-callout p {
  margin-bottom: 6px;
  font-weight: 500;
  color: var(--text-primary);
}

.math-callout p:last-child {
  margin-bottom: 0;
}

/* Data Tables inside article */
.data-table {
  width: 100%;
  border-collapse: collapse;
  margin: 24px 0;
  font-size: 14px;
  text-align: left;
}

.data-table th, .data-table td {
  padding: 12px 16px;
  border-bottom: 1px solid var(--border-color);
}

.data-table th {
  background-color: var(--bg-tertiary);
  font-family: 'Outfit', sans-serif;
  font-weight: 600;
}

.data-table tr:hover {
  background-color: rgba(36, 46, 66, 0.1);
}

/* Accordion FAQs styles */
.faq-container {
  max-width: 800px;
  margin: 0 auto;
}

.faq-title {
  font-size: 24px;
  margin-bottom: 24px;
  text-align: center;
}

.faq-item {
  background-color: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: 12px;
  margin-bottom: 16px;
  overflow: hidden;
  transition: all 0.2s ease;
}

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

.faq-question {
  padding: 18px 24px;
  font-family: 'Outfit', sans-serif;
  font-size: 16px;
  font-weight: 600;
  cursor: pointer;
  list-style: none;
  display: flex;
  justify-content: space-between;
  align-items: center;
  user-select: none;
}

/* Custom indicator symbol for accordion */
.faq-question::after {
  content: "+";
  font-size: 18px;
  font-weight: 400;
  color: var(--text-secondary);
  transition: transform 0.2s ease;
}

.faq-item[open] .faq-question::after {
  content: "\2212"; /* Minus symbol */
}

.faq-answer {
  padding: 0 24px 20px 24px;
  border-top: 1px solid transparent;
  color: var(--text-secondary);
  font-size: 14px;
  line-height: 1.6;
}

.faq-item[open] .faq-answer {
  border-top-color: var(--border-color);
}

/* Footer layout styling */
.site-footer {
  margin-top: 80px;
  background-color: var(--bg-secondary);
  border-top: 1px solid var(--border-color);
  padding: 48px 24px 24px 24px;
}

.footer-container {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 32px;
  margin-bottom: 32px;
}

.footer-brand h4 {
  font-size: 18px;
  margin-bottom: 8px;
}

.footer-brand p {
  color: var(--text-muted);
  font-size: 13px;
}

.footer-links {
  display: flex;
  gap: 24px;
}

.footer-links a {
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 14px;
  font-weight: 500;
  transition: color 0.2s;
}

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

.footer-bottom {
  max-width: 1200px;
  margin: 0 auto;
  border-top: 1px solid var(--border-color);
  padding-top: 24px;
  text-align: center;
}

.footer-bottom p {
  color: var(--text-muted);
  font-size: 12px;
}

/* Media Queries for Mobile Responsiveness */
@media (max-width: 992px) {
  .calc-grid {
    grid-template-columns: 1fr;
    gap: 24px;
  }
}

@media (max-width: 768px) {
  .hero-title {
    font-size: 28px;
  }
  
  .main-wrapper {
    padding: 24px 16px;
  }
  
  .calc-card {
    padding: 20px;
  }
  
  .results-grid {
    grid-template-columns: 1fr;
  }
  
  .back-text {
    display: none; /* Hide back link label text on small screens as requested */
  }
  
  .footer-container {
    flex-direction: column;
    align-items: center;
    text-align: center;
    gap: 20px;
  }
  
  .footer-links {
    flex-direction: column;
    align-items: center;
    gap: 12px;
  }
}

@media (max-width: 480px) {
  .header-container {
    padding: 12px 16px;
  }
  
  .quick-nav {
    display: none; /* Hide navigation helpers on very tight devices if necessary */
  }
  
  .tabs-container {
    border-radius: 10px;
  }
  
  .tab-btn {
    padding: 10px 8px;
    font-size: 13px;
  }
  
  .result-val.highlight-accent {
    font-size: 28px;
  }
}
.no-pmi-message {
  text-align: center;
  padding: 2rem 1rem;
  color: var(--text-secondary);
  font-size: 0.95rem;
}