/* ===== CSS Custom Properties ===== */
:root {
  --color-navy:       #1B2D5B;
  --color-navy-light: #2A4080;
  --color-blue:       #3B5998;
  --color-blue-light: #5B7BD5;
  --color-blue-pale:  #E8EDF8;
  --color-grey-50:    #F8FAFE;
  --color-grey-100:   #F0F2F7;
  --color-grey-200:   #E0E4ED;
  --color-grey-300:   #C5CAD8;
  --color-grey-600:   #6B7280;
  --color-grey-900:   #1A1A2E;
  --color-white:      #FFFFFF;
  --color-success:    #10B981;
  --color-error:      #EF4444;

  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;

  --space-xs:  0.25rem;
  --space-sm:  0.5rem;
  --space-md:  1rem;
  --space-lg:  2rem;
  --space-xl:  3rem;
  --space-2xl: 5rem;

  --max-width: 1200px;
  --radius:    8px;
  --radius-lg: 12px;
  --shadow:    0 1px 3px rgba(27,45,91,0.08), 0 4px 12px rgba(27,45,91,0.04);
  --shadow-lg: 0 4px 12px rgba(27,45,91,0.12), 0 12px 32px rgba(27,45,91,0.06);
  --transition: 0.2s ease;
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: 80px;
}

body {
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.6;
  color: var(--color-grey-900);
  background: var(--color-white);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

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

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

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

/* ===== Typography ===== */
h1, h2, h3 {
  line-height: 1.2;
  color: var(--color-navy);
}

h1 {
  font-size: clamp(2.25rem, 5vw, 3.5rem);
  font-weight: 800;
  letter-spacing: -0.03em;
}

h2 {
  font-size: clamp(1.75rem, 3.5vw, 2.5rem);
  font-weight: 700;
  letter-spacing: -0.02em;
}

h3 {
  font-size: 1.25rem;
  font-weight: 600;
}

.section-title {
  text-align: center;
  margin-bottom: var(--space-md);
}

.section-sub {
  text-align: center;
  color: var(--color-grey-600);
  font-size: 1.125rem;
  max-width: 640px;
  margin: 0 auto var(--space-xl);
}

/* ===== Layout ===== */
.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--space-lg);
}

section {
  padding: var(--space-2xl) 0;
}

/* ===== Buttons ===== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  font-family: var(--font-sans);
  font-size: 1rem;
  font-weight: 600;
  border: 2px solid transparent;
  border-radius: var(--radius);
  padding: 0.75rem 1.5rem;
  cursor: pointer;
  transition: all var(--transition);
  white-space: nowrap;
}

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

.btn-primary:hover {
  background: var(--color-navy-light);
  border-color: var(--color-navy-light);
  color: var(--color-white);
}

.btn-ghost {
  background: transparent;
  color: var(--color-navy);
  border-color: var(--color-grey-200);
}

.btn-ghost:hover {
  border-color: var(--color-navy);
  color: var(--color-navy);
}

.btn-lg {
  font-size: 1.125rem;
  padding: 1rem 2rem;
  border-radius: var(--radius-lg);
}

/* ===== Header ===== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255,255,255,0.95);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid transparent;
  transition: border-color var(--transition), box-shadow var(--transition);
}

.site-header.scrolled {
  border-bottom-color: var(--color-grey-200);
  box-shadow: var(--shadow);
}

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

.logo img {
  height: 36px;
  width: auto;
}

.main-nav {
  display: flex;
  gap: var(--space-lg);
}

.main-nav a {
  font-size: 0.9375rem;
  font-weight: 500;
  color: var(--color-grey-600);
}

.main-nav a:hover {
  color: var(--color-navy);
}

.header-cta {
  font-size: 0.875rem;
  padding: 0.5rem 1.25rem;
}

.mobile-menu-btn {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
}

.mobile-menu-btn span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--color-navy);
  border-radius: 2px;
  transition: all var(--transition);
}

/* ===== Hero ===== */
.hero {
  padding: var(--space-2xl) 0 var(--space-xl);
  background: linear-gradient(180deg, var(--color-white) 0%, var(--color-grey-50) 100%);
}

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

.hero-badge {
  display: inline-block;
  font-size: 0.8125rem;
  font-weight: 600;
  color: var(--color-blue);
  background: var(--color-blue-pale);
  padding: 0.375rem 1rem;
  border-radius: 100px;
  margin-bottom: var(--space-lg);
  letter-spacing: 0.02em;
  text-transform: uppercase;
}

.hero-sub {
  font-size: 1.25rem;
  color: var(--color-grey-600);
  margin-top: var(--space-md);
  max-width: 540px;
  line-height: 1.7;
}

.hero-actions {
  display: flex;
  gap: var(--space-md);
  margin-top: var(--space-xl);
  flex-wrap: wrap;
}

.hero-illustration img {
  width: 100%;
  max-width: 520px;
  margin: 0 auto;
}

/* ===== Problem ===== */
.problem {
  background: var(--color-grey-50);
}

.problem-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-lg);
  margin-top: var(--space-xl);
}

.problem-card {
  background: var(--color-white);
  border: 1px solid var(--color-grey-200);
  border-radius: var(--radius-lg);
  padding: var(--space-lg);
  transition: transform var(--transition), box-shadow var(--transition);
}

.problem-card:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
}

.problem-icon {
  margin-bottom: var(--space-md);
}

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

.problem-card p {
  color: var(--color-grey-600);
  font-size: 0.9375rem;
  line-height: 1.6;
}

/* ===== Product ===== */
.product-inner {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-xl);
  align-items: center;
}

.product-inner .section-title {
  text-align: left;
}

.product-inner .section-sub {
  text-align: left;
  margin: 0 0 var(--space-lg);
  max-width: none;
}

.product-features {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: var(--space-md);
}

.product-features li {
  padding-left: 1.5rem;
  position: relative;
}

.product-features li::before {
  content: '';
  position: absolute;
  left: 0;
  top: 0.5rem;
  width: 8px;
  height: 8px;
  background: var(--color-blue);
  border-radius: 50%;
}

.product-features strong {
  display: block;
  color: var(--color-navy);
  margin-bottom: var(--space-xs);
}

.product-features span {
  color: var(--color-grey-600);
  font-size: 0.9375rem;
}

.product-photo {
  width: 100%;
  border-radius: var(--radius-lg);
  object-fit: contain;
}

/* ===== OpenClaw ===== */
.openclaw {
  background: var(--color-grey-50);
}

.openclaw-inner {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-xl);
  align-items: center;
}

.openclaw-text .section-title {
  text-align: left;
}

.openclaw-text .section-sub {
  text-align: left;
  margin: 0 0 var(--space-lg);
  max-width: none;
}

.feature-list {
  display: flex;
  flex-direction: column;
  gap: var(--space-lg);
}

.feature-item {
  display: flex;
  gap: var(--space-md);
}

.feature-icon {
  flex-shrink: 0;
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--color-blue-pale);
  border-radius: var(--radius);
}

.feature-icon svg {
  width: 20px;
  height: 20px;
}

.feature-item strong {
  display: block;
  color: var(--color-navy);
  margin-bottom: var(--space-xs);
}

.feature-item p {
  color: var(--color-grey-600);
  font-size: 0.9375rem;
  margin: 0;
}

.openclaw-illustration img {
  width: 100%;
  max-width: 480px;
  margin: 0 auto;
}

/* ===== Models ===== */
.models-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-lg);
}

.model-card {
  background: var(--color-white);
  border: 1px solid var(--color-grey-200);
  border-radius: var(--radius-lg);
  padding: var(--space-lg);
  transition: transform var(--transition), box-shadow var(--transition);
}

.model-card:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
}

.model-card h3 {
  color: var(--color-navy);
  margin-bottom: var(--space-sm);
}

.model-strength {
  color: var(--color-grey-600);
  font-size: 0.9375rem;
  margin-bottom: var(--space-sm);
}

.model-params {
  font-size: 0.8125rem;
  color: var(--color-blue);
  font-weight: 600;
}

.model-card-more {
  border-style: dashed;
  background: var(--color-grey-50);
}

.model-card-more .model-strength {
  font-size: 0.875rem;
}

/* ===== Use Cases ===== */
.use-cases {
  background: var(--color-grey-50);
}

.use-cases-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-lg);
  margin-top: var(--space-xl);
}

.use-case-card {
  background: var(--color-white);
  border: 1px solid var(--color-grey-200);
  border-radius: var(--radius-lg);
  padding: var(--space-lg);
  transition: transform var(--transition), box-shadow var(--transition);
}

.use-case-card:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
}

.use-case-icon {
  margin-bottom: var(--space-md);
}

.use-case-card h3 {
  font-size: 1.0625rem;
  margin-bottom: var(--space-sm);
}

.use-case-card p {
  color: var(--color-grey-600);
  font-size: 0.9375rem;
  line-height: 1.6;
}

/* ===== Specs ===== */
.specs-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-xl);
  margin-top: var(--space-xl);
}

.specs-col h3 {
  font-size: 1.25rem;
  margin-bottom: var(--space-md);
  padding-bottom: var(--space-sm);
  border-bottom: 2px solid var(--color-navy);
}

.specs-table {
  width: 100%;
  border-collapse: collapse;
}

.specs-table tr {
  border-bottom: 1px solid var(--color-grey-200);
}

.specs-table td {
  padding: 0.75rem 0;
  font-size: 0.9375rem;
}

.specs-table td:first-child {
  font-weight: 600;
  color: var(--color-navy);
  white-space: nowrap;
  padding-right: var(--space-lg);
  width: 35%;
}

.specs-table td:last-child {
  color: var(--color-grey-600);
}

/* ===== Economics ===== */
.economics {
  background: var(--color-grey-50);
}

.cost-comparison {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  gap: var(--space-lg);
  align-items: stretch;
  margin-top: var(--space-xl);
}

.cost-card {
  background: var(--color-white);
  border-radius: var(--radius-lg);
  padding: var(--space-xl) var(--space-lg);
  border: 2px solid var(--color-grey-200);
}

.cost-card h3 {
  font-size: 1.25rem;
  margin-bottom: var(--space-xs);
}

.cost-label {
  font-size: 0.875rem;
  color: var(--color-grey-600);
  margin-bottom: var(--space-lg);
  line-height: 1.5;
}

.cost-amount {
  font-size: clamp(2.5rem, 4vw, 3.5rem);
  font-weight: 800;
  color: var(--color-navy);
  letter-spacing: -0.03em;
  line-height: 1.1;
  margin-bottom: var(--space-lg);
}

.cost-dollar {
  font-size: 0.6em;
  font-weight: 600;
  vertical-align: 0.15em;
}

.cost-period {
  font-size: 0.35em;
  font-weight: 500;
  color: var(--color-grey-600);
  letter-spacing: 0;
}

.cost-details {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
}

.cost-details li {
  font-size: 0.9375rem;
  color: var(--color-grey-600);
  padding-left: 1.25rem;
  position: relative;
  line-height: 1.5;
}

.cost-details li::before {
  content: '';
  position: absolute;
  left: 0;
  top: 0.55rem;
  width: 6px;
  height: 6px;
  border-radius: 50%;
}

.cost-cloud {
  border-color: var(--color-grey-300);
}

.cost-cloud .cost-amount {
  color: var(--color-grey-600);
}

.cost-cloud .cost-details li::before {
  background: var(--color-grey-300);
}

.cost-owned {
  border-color: var(--color-navy);
  box-shadow: var(--shadow-lg);
}

.cost-owned .cost-details li::before {
  background: var(--color-blue);
}

.cost-vs {
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--color-grey-300);
  padding-top: 4rem;
}

.cost-extras {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-lg);
  margin-top: var(--space-xl);
}

.cost-extra {
  font-size: 0.9375rem;
  color: var(--color-grey-600);
  line-height: 1.6;
}

.cost-extra strong {
  display: block;
  color: var(--color-navy);
  margin-bottom: var(--space-xs);
}

/* ===== Reservation ===== */
.reserve {
  background: var(--color-white);
}

.reserve-inner {
  max-width: 720px;
  margin: 0 auto;
}

.reserve-text {
  margin-bottom: var(--space-xl);
}

.reserve-form {
  display: flex;
  flex-direction: column;
  gap: var(--space-md);
}

.form-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-md);
}

.form-group {
  display: flex;
  flex-direction: column;
  gap: var(--space-xs);
}

.form-group-full {
  grid-column: 1 / -1;
}

.form-group label {
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--color-navy);
}

.required {
  color: var(--color-error);
}

.optional {
  font-weight: 400;
  color: var(--color-grey-600);
}

.form-group input,
.form-group select,
.form-group textarea {
  font-family: var(--font-sans);
  font-size: 1rem;
  padding: 0.75rem 1rem;
  border: 1.5px solid var(--color-grey-300);
  border-radius: var(--radius);
  background: var(--color-white);
  color: var(--color-grey-900);
  transition: border-color var(--transition), box-shadow var(--transition);
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
  outline: none;
  border-color: var(--color-blue);
  box-shadow: 0 0 0 3px rgba(59,89,152,0.15);
}

.form-group input.error,
.form-group select.error {
  border-color: var(--color-error);
}

.form-group textarea {
  resize: vertical;
  min-height: 80px;
}

.form-submit {
  margin-top: var(--space-md);
  text-align: center;
}

.form-submit .btn {
  width: 100%;
  max-width: 360px;
}

.form-note {
  margin-top: var(--space-md);
  font-size: 0.8125rem;
  color: var(--color-grey-600);
}

.form-message {
  text-align: center;
  padding: var(--space-lg);
  border-radius: var(--radius);
  font-weight: 500;
}

.form-message.success {
  background: #ecfdf5;
  color: #065f46;
  border: 1px solid #a7f3d0;
}

.form-message.error {
  background: #fef2f2;
  color: #991b1b;
  border: 1px solid #fecaca;
}

/* ===== FAQ ===== */
.faq {
  background: var(--color-grey-50);
}

.faq-list {
  max-width: 720px;
  margin: var(--space-xl) auto 0;
}

.faq-item {
  border-bottom: 1px solid var(--color-grey-200);
}

.faq-item:first-child {
  border-top: 1px solid var(--color-grey-200);
}

.faq-item summary {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1.25rem 0;
  font-size: 1.0625rem;
  font-weight: 600;
  color: var(--color-navy);
  cursor: pointer;
  list-style: none;
  transition: color var(--transition);
}

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

.faq-item summary::after {
  content: '+';
  font-size: 1.5rem;
  font-weight: 300;
  color: var(--color-grey-600);
  transition: transform var(--transition);
  flex-shrink: 0;
  margin-left: var(--space-md);
}

.faq-item[open] summary::after {
  content: '\2212';
}

.faq-item summary:hover {
  color: var(--color-blue);
}

.faq-answer {
  padding-bottom: 1.25rem;
}

.faq-answer p {
  color: var(--color-grey-600);
  line-height: 1.7;
}

/* ===== Footer ===== */
.site-footer {
  border-top: 1px solid var(--color-grey-200);
  padding: var(--space-xl) 0;
}

.footer-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.footer-brand {
  display: flex;
  align-items: center;
  gap: var(--space-lg);
}

.footer-brand p {
  font-size: 0.8125rem;
  color: var(--color-grey-600);
}

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

.footer-links a {
  font-size: 0.8125rem;
  color: var(--color-grey-600);
}

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

/* ===== Legal Pages ===== */
.legal-page {
  padding-top: var(--space-2xl);
  padding-bottom: var(--space-2xl);
  max-width: 720px;
  margin: 0 auto;
}

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

.legal-page h2 {
  font-size: 1.25rem;
  margin-top: var(--space-xl);
  margin-bottom: var(--space-sm);
}

.legal-updated {
  font-size: 0.875rem;
  color: var(--color-grey-600);
  margin-bottom: var(--space-xl);
}

.legal-page p,
.legal-page li {
  color: var(--color-grey-600);
  line-height: 1.7;
  margin-bottom: var(--space-md);
}

.legal-page ul {
  padding-left: 1.5rem;
  margin-bottom: var(--space-md);
}

.legal-page li {
  margin-bottom: var(--space-xs);
}

/* ===== Scroll Animations ===== */
.reveal {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}

/* ===== Mobile Navigation Overlay ===== */
.mobile-nav-overlay {
  display: none;
  position: fixed;
  inset: 0;
  z-index: 99;
  background: rgba(255,255,255,0.98);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: var(--space-lg);
}

.mobile-nav-overlay.active {
  display: flex;
}

.mobile-nav-overlay a {
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--color-navy);
}

.mobile-nav-overlay .btn {
  margin-top: var(--space-md);
}

/* ===== Responsive ===== */
@media (max-width: 1023px) {
  .hero-inner {
    grid-template-columns: 1fr;
    text-align: center;
  }

  .hero-sub {
    margin-left: auto;
    margin-right: auto;
  }

  .hero-actions {
    justify-content: center;
  }

  .hero-illustration {
    order: -1;
    max-width: 400px;
    margin: 0 auto;
  }

  .problem-grid {
    grid-template-columns: 1fr;
    max-width: 480px;
    margin-left: auto;
    margin-right: auto;
  }

  .product-inner,
  .openclaw-inner {
    grid-template-columns: 1fr;
  }

  .product-inner .section-title,
  .product-inner .section-sub,
  .openclaw-text .section-title,
  .openclaw-text .section-sub {
    text-align: center;
  }

  .product-image,
  .openclaw-illustration {
    order: -1;
    max-width: 400px;
    margin: 0 auto;
  }

  .models-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .use-cases-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .specs-grid {
    grid-template-columns: 1fr;
  }

  .cost-comparison {
    grid-template-columns: 1fr;
  }

  .cost-vs {
    padding-top: 0;
  }

  .cost-extras {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 767px) {
  :root {
    --space-2xl: 3rem;
  }

  .main-nav,
  .header-cta {
    display: none;
  }

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

  h1 {
    font-size: 2rem;
  }

  .hero-actions {
    flex-direction: column;
    align-items: center;
  }

  .hero-actions .btn {
    width: 100%;
    max-width: 320px;
  }

  .models-grid {
    grid-template-columns: 1fr;
  }

  .use-cases-grid {
    grid-template-columns: 1fr;
  }

  .form-row {
    grid-template-columns: 1fr;
  }

  .footer-inner {
    flex-direction: column;
    gap: var(--space-lg);
    text-align: center;
  }

  .footer-brand {
    flex-direction: column;
    gap: var(--space-sm);
  }

  .footer-links {
    flex-wrap: wrap;
    justify-content: center;
  }

}