/* ============================================================
   QHelperService Homepage Styles
   Design System: "The Architectural Whisper"
   - Premium Minimalism, high-clarity light theme
   - Primary blue #0066CC as action beacon
   - Manrope typeface for geometric balance
   - 8px baseline grid, 1280px container
   ============================================================ */

/* ── CSS Custom Properties (Design Tokens) ────────────────── */
:root {
  /* Colors */
  --surface: #f8f9fa;
  --surface-dim: #d9dadb;
  --surface-bright: #f8f9fa;
  --surface-container-lowest: #ffffff;
  --surface-container-low: #f3f4f5;
  --surface-container: #edeeef;
  --surface-container-high: #e7e8e9;
  --surface-container-highest: #e1e3e4;
  --on-surface: #191c1d;
  --on-surface-variant: #414753;
  --inverse-surface: #2e3132;
  --inverse-on-surface: #f0f1f2;
  --outline: #727784;
  --outline-variant: #c1c6d5;
  --surface-tint: #005cba;
  --primary: #004e9f;
  --on-primary: #ffffff;
  --primary-container: #0066cc;
  --on-primary-container: #dfe8ff;
  --inverse-primary: #aac7ff;
  --secondary: #476083;
  --on-secondary: #ffffff;
  --secondary-container: #bdd6ff;
  --on-secondary-container: #445d80;
  --tertiary: #883700;
  --on-tertiary: #ffffff;
  --tertiary-container: #af4900;
  --on-tertiary-container: #ffe3d6;
  --error: #ba1a1a;
  --on-error: #ffffff;
  --error-container: #ffdad6;
  --on-error-container: #93000a;
  --background: #f8f9fa;
  --on-background: #191c1d;
  --surface-variant: #e1e3e4;

  /* Typography */
  --font-family: 'Manrope', 'Segoe UI', 'PingFang SC', 'Microsoft YaHei', sans-serif;
  --h1-size: 72px;
  --h1-weight: 700;
  --h1-line-height: 1.1;
  --h1-letter-spacing: -0.04em;
  --h2-size: 48px;
  --h2-weight: 600;
  --h2-line-height: 1.2;
  --h2-letter-spacing: -0.02em;
  --h3-size: 32px;
  --h3-weight: 600;
  --h3-line-height: 1.3;
  --h3-letter-spacing: -0.01em;
  --body-lg-size: 18px;
  --body-lg-weight: 400;
  --body-lg-line-height: 1.6;
  --body-md-size: 16px;
  --body-md-weight: 400;
  --body-md-line-height: 1.6;
  --label-caps-size: 12px;
  --label-caps-weight: 700;
  --label-caps-letter-spacing: 0.1em;

  /* Rounded */
  --radius-sm: 0.125rem;
  --radius: 0.25rem;
  --radius-md: 0.375rem;
  --radius-lg: 0.5rem;
  --radius-xl: 0.75rem;
  --radius-full: 9999px;

  /* Spacing */
  --spacing-unit: 8px;
  --container-max: 1280px;
  --gutter: 32px;
  --section-padding: 120px;
  --stack-sm: 16px;
  --stack-md: 32px;
  --stack-lg: 64px;

  /* Shadows */
  --shadow-level-1: 0 1px 3px rgba(0, 0, 0, 0.04);
  --shadow-level-2: 0 8px 24px rgba(0, 0, 0, 0.1);
}

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

body {
  margin: 0;
  padding: 0;
  font-family: var(--font-family);
  font-size: var(--body-md-size);
  font-weight: var(--body-md-weight);
  line-height: var(--body-md-line-height);
  color: var(--on-surface);
  background-color: var(--background);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

h1, h2, h3, h4, h5, h6 {
  margin: 0 0 var(--stack-sm);
  color: var(--on-surface);
}

p {
  margin: 0 0 var(--stack-sm);
}

a {
  color: var(--primary-container);
  text-decoration: none;
  transition: color 0.2s ease;
}

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

ul, ol {
  margin: 0;
  padding-left: var(--stack-sm);
}

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

/* ── Container ────────────────────────────────────────────── */
.container {
  width: 100%;
  max-width: var(--container-max);
  margin-left: auto;
  margin-right: auto;
  padding-left: var(--gutter);
  padding-right: var(--gutter);
}

/* ── Section Spacing ──────────────────────────────────────── */
.section {
  padding-top: var(--section-padding);
  padding-bottom: var(--section-padding);
}

@media (max-width: 768px) {
  .section {
    padding-top: var(--stack-lg);
    padding-bottom: var(--stack-lg);
  }
}

/* ── Typography ───────────────────────────────────────────── */
.display-h1 {
  font-size: var(--h1-size);
  font-weight: var(--h1-weight);
  line-height: var(--h1-line-height);
  letter-spacing: var(--h1-letter-spacing);
}

.display-h2 {
  font-size: var(--h2-size);
  font-weight: var(--h2-weight);
  line-height: var(--h2-line-height);
  letter-spacing: var(--h2-letter-spacing);
}

.section-h3 {
  font-size: var(--h3-size);
  font-weight: var(--h3-weight);
  line-height: var(--h3-line-height);
  letter-spacing: var(--h3-letter-spacing);
}

.body-lg {
  font-size: var(--body-lg-size);
  font-weight: var(--body-lg-weight);
  line-height: var(--body-lg-line-height);
}

.body-md {
  font-size: var(--body-md-size);
  font-weight: var(--body-md-weight);
  line-height: var(--body-md-line-height);
}

.label-caps {
  font-size: var(--label-caps-size);
  font-weight: var(--label-caps-weight);
  line-height: 1;
  letter-spacing: var(--label-caps-letter-spacing);
  text-transform: uppercase;
}

@media (max-width: 768px) {
  .display-h1 {
    font-size: clamp(36px, 8vw, 48px);
  }
  .display-h2 {
    font-size: clamp(28px, 6vw, 36px);
  }
  .section-h3 {
    font-size: clamp(20px, 4vw, 28px);
  }
}

/* ── Buttons ──────────────────────────────────────────────── */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 12px 32px;
  font-family: var(--font-family);
  font-size: var(--body-md-size);
  font-weight: 700;
  line-height: 1.5;
  border-radius: var(--radius);
  cursor: pointer;
  transition: all 0.2s ease;
  text-decoration: none;
  border: 1px solid transparent;
}

.btn-primary {
  background-color: var(--primary-container);
  color: var(--on-primary);
  border-color: var(--primary-container);
}

.btn-primary:hover {
  background-color: var(--primary);
  border-color: var(--primary);
  color: var(--on-primary);
  box-shadow: var(--shadow-level-2);
}

.btn-secondary {
  background-color: transparent;
  color: var(--on-surface);
  border: 1px solid var(--outline-variant);
}

.btn-secondary:hover {
  background-color: var(--surface-container-low);
  border-color: var(--outline);
  color: var(--on-surface);
}

.btn-lg {
  padding: 16px 40px;
  font-size: var(--body-lg-size);
}

/* ── Hero Section ─────────────────────────────────────────── */
.hero-section {
  background-color: var(--surface-container-lowest);
  padding-top: calc(var(--section-padding) + 40px);
  padding-bottom: var(--section-padding);
  border-bottom: 1px solid var(--surface-variant);
}

.hero-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--stack-lg);
  align-items: center;
}

.hero-content {
  max-width: 600px;
}

.hero-title {
  margin-bottom: var(--stack-md);
  color: var(--inverse-surface);
}

.hero-subtitle {
  font-size: var(--body-lg-size);
  color: var(--on-surface-variant);
  margin-bottom: var(--stack-lg);
  line-height: 1.7;
}

.hero-actions {
  display: flex;
  gap: var(--stack-sm);
  flex-wrap: wrap;
}

.hero-visual {
  background: var(--surface-container);
  border-radius: var(--radius-lg);
  padding: var(--stack-md);
  box-shadow: var(--shadow-level-2);
  min-height: 400px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--on-surface-variant);
  font-size: var(--body-lg-size);
}

@media (max-width: 992px) {
  .hero-grid {
    grid-template-columns: 1fr;
  }
  .hero-content {
    max-width: 100%;
  }
}

/* ── Feature Grid ─────────────────────────────────────────── */
.feature-section {
  background-color: var(--surface-container-lowest);
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--stack-lg) var(--stack-md);
}

.feature-grid .feature-card:nth-child(5) {
  grid-column: 1 / -1;
}

.feature-card {
  border-top: 1px solid var(--outline-variant);
  padding-top: var(--stack-md);
  background: transparent;
  transition: all 0.2s ease;
}

.feature-card:hover {
  border-top-color: var(--primary-container);
}

.feature-card-icon {
  width: 48px;
  height: 48px;
  border-radius: var(--radius-md);
  background: var(--surface-container);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: var(--stack-sm);
  color: var(--primary-container);
  font-size: 1.5rem;
}

.feature-card h3 {
  font-size: var(--body-lg-size);
  font-weight: 700;
  color: var(--on-surface);
  margin-bottom: var(--stack-sm);
}

.feature-card p {
  color: var(--on-surface-variant);
  margin-bottom: var(--stack-sm);
}

.feature-card ul {
  list-style: none;
  padding: 0;
}

.feature-card ul li {
  position: relative;
  padding-left: 24px;
  margin-bottom: 8px;
  color: var(--on-surface-variant);
  font-size: var(--body-md-size);
}

.feature-card ul li::before {
  content: '';
  position: absolute;
  left: 0;
  top: 8px;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--primary-container);
}

@media (max-width: 768px) {
  .feature-grid {
    grid-template-columns: 1fr;
  }
  .feature-grid .feature-card:nth-child(5) {
    grid-column: auto;
  }
}

/* ── Pricing Cards ────────────────────────────────────────── */
.pricing-section {
  background-color: var(--surface);
}

.pricing-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--stack-md);
}

.pricing-card {
  background: var(--surface-container-lowest);
  border-radius: var(--radius-lg);
  padding: var(--stack-md);
  border: 1px solid var(--surface-variant);
  transition: all 0.2s ease;
  display: flex;
  flex-direction: column;
}

.pricing-card:hover {
  box-shadow: var(--shadow-level-2);
  border-color: var(--primary-container);
  transform: translateY(-4px);
}

.pricing-card-header h3 {
  font-size: var(--body-lg-size);
  font-weight: 700;
  margin-bottom: 4px;
}

.pricing-card-header p {
  font-size: var(--body-md-size);
  color: var(--on-surface-variant);
  margin-bottom: var(--stack-md);
}

.pricing-card-body {
  flex: 1;
}

.pricing-card-body .spec-item {
  display: flex;
  justify-content: space-between;
  padding: 8px 0;
  border-bottom: 1px solid var(--surface-container);
}

.pricing-card-body .spec-item:last-child {
  border-bottom: none;
}

.pricing-card-body .spec-label {
  color: var(--on-surface-variant);
}

.pricing-card-body .spec-value {
  font-weight: 600;
  color: var(--on-surface);
}

.pricing-card-footer {
  margin-top: var(--stack-md);
  padding-top: var(--stack-sm);
  border-top: 1px solid var(--surface-variant);
}

.pricing-card-footer .price {
  font-size: var(--h3-size);
  font-weight: 700;
  color: var(--primary-container);
  margin-bottom: 4px;
}

.pricing-card-footer .price-desc {
  font-size: var(--body-md-size);
  color: var(--on-surface-variant);
  margin-bottom: var(--stack-sm);
}

.pricing-card-footer .btn {
  width: 100%;
}

@media (max-width: 1200px) {
  .pricing-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 576px) {
  .pricing-grid {
    grid-template-columns: 1fr;
  }
}

/* ── CTA Section ──────────────────────────────────────────── */
.cta-section {
  background-color: var(--surface-container-lowest);
  text-align: center;
}

.cta-title {
  margin-bottom: var(--stack-sm);
}

.cta-subtitle {
  font-size: var(--body-lg-size);
  color: var(--on-surface-variant);
  margin-bottom: var(--stack-lg);
}

.cta-actions {
  display: flex;
  justify-content: center;
  gap: var(--stack-sm);
  flex-wrap: wrap;
}

/* ── Testimonial Section ──────────────────────────────────── */
.testimonial-section {
  background-color: var(--surface);
  text-align: center;
}

.testimonial-quote {
  font-size: var(--h3-size);
  font-style: italic;
  color: var(--on-surface);
  max-width: 800px;
  margin: 0 auto var(--stack-md);
  line-height: 1.5;
}

.testimonial-attr {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--stack-sm);
}

.testimonial-attr::before {
  content: '';
  width: 1px;
  height: 24px;
  background: var(--outline-variant);
}

.testimonial-attr span {
  font-size: var(--body-md-size);
  color: var(--on-surface-variant);
  font-weight: 600;
}

/* ── Language Switcher ────────────────────────────────────── */
.lang-switcher {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  padding: 6px 12px;
  border: 1px solid var(--outline-variant);
  border-radius: var(--radius);
  background: var(--surface-container-lowest);
  cursor: pointer;
  font-size: var(--body-md-size);
  font-weight: 600;
  color: var(--on-surface);
  transition: all 0.2s ease;
  position: relative;
}

.lang-switcher:hover {
  border-color: var(--primary-container);
  background: var(--surface-container);
}

.lang-switcher-dropdown {
  position: absolute;
  top: 100%;
  right: 0;
  margin-top: 4px;
  background: var(--surface-container-lowest);
  border: 1px solid var(--outline-variant);
  border-radius: var(--radius);
  box-shadow: var(--shadow-level-2);
  min-width: 140px;
  z-index: 1000;
  display: none;
}

.lang-switcher-dropdown.show {
  display: block;
}

.lang-switcher-option {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 10px 16px;
  cursor: pointer;
  transition: background 0.15s ease;
  font-size: var(--body-md-size);
  color: var(--on-surface);
}

.lang-switcher-option:hover {
  background: var(--surface-container);
}

.lang-switcher-option.active {
  color: var(--primary-container);
  font-weight: 700;
}

/* ── Navbar Enhancement ───────────────────────────────────── */
.navbar-custom {
  background-color: var(--surface-container-lowest) !important;
  border-bottom: 1px solid var(--surface-variant);
  padding: var(--stack-sm) 0;
}

.navbar-custom .navbar-brand {
  font-weight: 700;
  font-size: var(--body-lg-size);
  color: var(--on-surface);
}

.navbar-custom .nav-link {
  color: var(--on-surface-variant);
  font-weight: 600;
  padding: 8px 16px;
  transition: color 0.2s ease;
}

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

/* ── Footer ───────────────────────────────────────────────── */
.footer-custom {
  background-color: var(--surface-container);
  border-top: 1px solid var(--surface-variant);
  padding: var(--stack-lg) 0;
  text-align: center;
  color: var(--on-surface-variant);
}

.footer-custom a {
  color: var(--primary-container);
}

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

/* ── Section Header ───────────────────────────────────────── */
.section-header {
  text-align: center;
  margin-bottom: var(--stack-lg);
}

.section-header .section-label {
  display: inline-block;
  margin-bottom: var(--stack-sm);
  color: var(--primary-container);
}

.section-header h2 {
  margin-bottom: var(--stack-sm);
}

.section-header p {
  font-size: var(--body-lg-size);
  color: var(--on-surface-variant);
  max-width: 640px;
  margin-left: auto;
  margin-right: auto;
}

/* ── Utility Classes ──────────────────────────────────────── */
.text-on-surface { color: var(--on-surface); }
.text-on-surface-variant { color: var(--on-surface-variant); }
.text-primary { color: var(--primary-container); }
.bg-surface { background-color: var(--surface); }
.bg-surface-lowest { background-color: var(--surface-container-lowest); }
.bg-surface-container { background-color: var(--surface-container); }
.mb-sm { margin-bottom: var(--stack-sm); }
.mb-md { margin-bottom: var(--stack-md); }
.mb-lg { margin-bottom: var(--stack-lg); }
.mx-auto { margin-left: auto; margin-right: auto; }
.text-center { text-align: center; }
.flex { display: flex; }
.flex-wrap { flex-wrap: wrap; }
.items-center { align-items: center; }
.justify-center { justify-content: center; }
.gap-sm { gap: var(--stack-sm); }
.gap-md { gap: var(--stack-md); }
.max-w-3xl { max-width: 48rem; }

/* ── Bootstrap Overrides ──────────────────────────────────── */
.row {
  --bs-gutter-x: 1.5rem;
  --bs-gutter-y: 0;
  display: flex;
  flex-wrap: wrap;
  margin-top: calc(-1 * var(--bs-gutter-y));
  margin-right: calc(-0.5 * var(--bs-gutter-x));
  margin-left: calc(-0.5 * var(--bs-gutter-x));
}

.row > * {
  flex-shrink: 0;
  width: 100%;
  max-width: 100%;
  padding-right: calc(var(--bs-gutter-x) * 0.5);
  padding-left: calc(var(--bs-gutter-x) * 0.5);
  margin-top: var(--bs-gutter-y);
}

.col-lg-6 {
  flex: 0 0 auto;
  width: 50%;
}

.col-lg-3 {
  flex: 0 0 auto;
  width: 25%;
}

.col-lg-4 {
  flex: 0 0 auto;
  width: 33.33333333%;
}

@media (max-width: 992px) {
  .col-lg-6,
  .col-lg-3,
  .col-lg-4 {
    width: 100%;
  }
}

.d-flex { display: flex; }
.justify-content-center { justify-content: center; }
.justify-content-between { justify-content: space-between; }
.align-items-center { align-items: center; }
.flex-wrap { flex-wrap: wrap; }
.gap-4 { gap: 1rem; }
.gap-6 { gap: 1.5rem; }
.text-center { text-align: center; }
.text-muted { color: var(--on-surface-variant) !important; }
.bg-white { background-color: var(--surface-container-lowest) !important; }
.bg-light { background-color: var(--surface) !important; }
.border-top { border-top: 1px solid var(--surface-variant) !important; }
.border-bottom { border-bottom: 1px solid var(--surface-variant) !important; }
.w-100 { width: 100% !important; }
.d-none { display: none !important; }
.d-block { display: block !important; }
.list-unstyled { padding-left: 0; list-style: none; }