/* ===== CSS Custom Properties ===== */
:root {
  --color-primary: #2563eb;
  --color-primary-dark: #1d4ed8;
  --color-primary-light: #dbeafe;
  --color-bg: #ffffff;
  --color-bg-alt: #f8fafc;
  --color-text: #1e293b;
  --color-text-muted: #64748b;
  --color-border: #e2e8f0;
  --color-success: #16a34a;
  --max-width: 1200px;
  --radius: 8px;
  --shadow: 0 1px 3px rgba(0, 0, 0, 0.1), 0 1px 2px rgba(0, 0, 0, 0.06);
  --shadow-lg: 0 10px 15px rgba(0, 0, 0, 0.1), 0 4px 6px rgba(0, 0, 0, 0.05);
}

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

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

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  font-size: 16px;
  line-height: 1.6;
  color: var(--color-text);
  background: var(--color-bg);
}

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

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

a:hover {
  text-decoration: underline;
}

ul {
  list-style: none;
}

/* ===== Container ===== */
.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 20px;
}

/* ===== Buttons ===== */
.btn {
  display: inline-block;
  padding: 12px 28px;
  border-radius: var(--radius);
  font-size: 1rem;
  font-weight: 600;
  text-decoration: none;
  cursor: pointer;
  border: 2px solid transparent;
  transition: background 0.2s, color 0.2s, border-color 0.2s;
}

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

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

.btn-secondary {
  background: transparent;
  color: var(--color-primary);
  border-color: var(--color-primary);
}

.btn-secondary:hover {
  background: var(--color-primary-light);
  text-decoration: none;
}

/* ===== Header ===== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--color-bg);
  border-bottom: 1px solid var(--color-border);
}

.site-header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}

.logo {
  font-size: 1.125rem;
  font-weight: 700;
  color: var(--color-text);
}

.logo:hover {
  text-decoration: none;
}

.main-nav {
  display: flex;
  gap: 24px;
}

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

.main-nav a:hover {
  color: var(--color-primary);
  text-decoration: none;
}

/* Mobile menu toggle */
.menu-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 8px;
}

.menu-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--color-text);
  transition: transform 0.2s;
}

/* ===== Hero ===== */
.hero {
  padding: 80px 0 60px;
  text-align: center;
}

.hero h1 {
  font-size: 2.5rem;
  font-weight: 800;
  line-height: 1.2;
  margin-bottom: 16px;
}

.hero-sub {
  font-size: 1.25rem;
  color: var(--color-text-muted);
  max-width: 640px;
  margin: 0 auto 32px;
}

.hero-actions {
  display: flex;
  gap: 16px;
  justify-content: center;
  flex-wrap: wrap;
  margin-bottom: 48px;
}

.hero-image {
  max-width: 800px;
  margin: 0 auto;
}

.placeholder-img {
  background: var(--color-bg-alt);
  border: 2px dashed var(--color-border);
  border-radius: var(--radius);
  padding: 80px 20px;
  color: var(--color-text-muted);
  font-size: 1rem;
}

/* ===== Features ===== */
.features {
  padding: 80px 0;
  background: var(--color-bg-alt);
}

.features h2,
.how-it-works h2,
.pricing h2,
.faq h2,
.contact h2 {
  text-align: center;
  font-size: 2rem;
  margin-bottom: 48px;
}

.features-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 24px;
}

.feature-card {
  background: var(--color-bg);
  border-radius: var(--radius);
  padding: 32px 24px;
  box-shadow: var(--shadow);
}

.feature-icon {
  font-size: 2rem;
  margin-bottom: 12px;
}

.feature-card h3 {
  font-size: 1.125rem;
  margin-bottom: 8px;
}

.feature-card p {
  color: var(--color-text-muted);
  font-size: 0.9375rem;
}

/* ===== How It Works ===== */
.how-it-works {
  padding: 80px 0;
}

.steps {
  display: grid;
  grid-template-columns: 1fr;
  gap: 32px;
  max-width: 800px;
  margin: 0 auto;
}

.step {
  text-align: center;
}

.step-number {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background: var(--color-primary);
  color: #fff;
  font-size: 1.25rem;
  font-weight: 700;
  margin-bottom: 16px;
}

.step h3 {
  font-size: 1.125rem;
  margin-bottom: 8px;
}

.step p {
  color: var(--color-text-muted);
  font-size: 0.9375rem;
}

/* ===== Pricing ===== */
.pricing {
  padding: 80px 0;
  background: var(--color-bg-alt);
}

.pricing-sub {
  text-align: center;
  color: var(--color-text-muted);
  margin-top: -32px;
  margin-bottom: 48px;
}

.pricing-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 24px;
  max-width: 960px;
  margin: 0 auto;
}

.pricing-card {
  background: var(--color-bg);
  border-radius: var(--radius);
  padding: 40px 32px;
  box-shadow: var(--shadow);
  text-align: center;
  position: relative;
}

.pricing-card.featured {
  border: 2px solid var(--color-primary);
  box-shadow: var(--shadow-lg);
}

.badge {
  position: absolute;
  top: -12px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--color-primary);
  color: #fff;
  padding: 4px 16px;
  border-radius: 20px;
  font-size: 0.8125rem;
  font-weight: 600;
}

.pricing-card h3 {
  font-size: 1.25rem;
  margin-bottom: 8px;
}

.price {
  font-size: 2.5rem;
  font-weight: 800;
  color: var(--color-text);
}

.price-period {
  color: var(--color-text-muted);
  font-size: 0.875rem;
  margin-bottom: 24px;
}

.pricing-card ul {
  text-align: left;
  margin-bottom: 32px;
}

.pricing-card li {
  padding: 8px 0;
  border-bottom: 1px solid var(--color-border);
  font-size: 0.9375rem;
  color: var(--color-text-muted);
}

.pricing-card li::before {
  content: "✓ ";
  color: var(--color-success);
  font-weight: 700;
}

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

/* ===== FAQ ===== */
.faq {
  padding: 80px 0;
}

.faq-list {
  max-width: 760px;
  margin: 0 auto;
}

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

.faq-item summary {
  padding: 20px 0;
  font-weight: 600;
  cursor: pointer;
  font-size: 1rem;
  list-style: none;
}

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

.faq-item summary::before {
  content: "+";
  display: inline-block;
  width: 24px;
  font-size: 1.25rem;
  color: var(--color-primary);
  font-weight: 700;
}

.faq-item[open] summary::before {
  content: "−";
}

.faq-item p {
  padding: 0 0 20px 24px;
  color: var(--color-text-muted);
  font-size: 0.9375rem;
}

/* ===== Contact ===== */
.contact {
  padding: 80px 0;
  background: var(--color-bg-alt);
}

.contact > .container > p {
  text-align: center;
  color: var(--color-text-muted);
  margin-bottom: 48px;
}

.contact-methods {
  display: grid;
  grid-template-columns: 1fr;
  gap: 48px;
  max-width: 900px;
  margin: 0 auto;
}

.contact-form label {
  display: block;
  font-weight: 600;
  font-size: 0.875rem;
  margin-bottom: 4px;
  margin-top: 16px;
}

.contact-form label:first-child {
  margin-top: 0;
}

.contact-form input,
.contact-form textarea {
  width: 100%;
  padding: 10px 12px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  font-size: 1rem;
  font-family: inherit;
  background: var(--color-bg);
  color: var(--color-text);
}

.contact-form input:focus,
.contact-form textarea:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px var(--color-primary-light);
}

.contact-form .btn {
  margin-top: 20px;
  width: 100%;
}

.contact-info {
  padding: 32px;
  background: var(--color-bg);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

.contact-info h3 {
  margin-bottom: 16px;
}

.contact-info p {
  margin-bottom: 12px;
  color: var(--color-text-muted);
  font-size: 0.9375rem;
}

/* ===== Footer ===== */
.site-footer {
  padding: 48px 0 24px;
  background: var(--color-text);
  color: #cbd5e1;
}

.footer-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 32px;
  margin-bottom: 32px;
}

.footer-company {
  font-weight: 700;
  color: #fff;
  margin-bottom: 4px;
}

.footer-address {
  font-size: 0.875rem;
}

.footer-links h4 {
  color: #fff;
  font-size: 0.875rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: 12px;
}

.footer-links a {
  display: block;
  color: #94a3b8;
  font-size: 0.875rem;
  padding: 4px 0;
}

.footer-links a:hover {
  color: #fff;
}

.footer-bottom {
  border-top: 1px solid #334155;
  padding-top: 24px;
  text-align: center;
  font-size: 0.8125rem;
  color: #64748b;
}

/* ===== Responsive: Tablet (640px+) ===== */
@media (min-width: 640px) {
  .features-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .steps {
    grid-template-columns: repeat(3, 1fr);
  }

  .pricing-grid {
    grid-template-columns: repeat(3, 1fr);
  }

  .contact-methods {
    grid-template-columns: 1fr 1fr;
  }

  .footer-grid {
    grid-template-columns: 2fr 1fr 1fr;
  }
}

/* ===== Responsive: Desktop (1024px+) ===== */
@media (min-width: 1024px) {
  .hero h1 {
    font-size: 3.5rem;
  }

  .hero-sub {
    font-size: 1.375rem;
  }

  .features-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

/* ===== Responsive: Mobile nav ===== */
@media (max-width: 639px) {
  .menu-toggle {
    display: flex;
  }

  .main-nav {
    display: none;
    position: absolute;
    top: 64px;
    left: 0;
    right: 0;
    background: var(--color-bg);
    border-bottom: 1px solid var(--color-border);
    flex-direction: column;
    padding: 16px 20px;
    gap: 12px;
    box-shadow: var(--shadow-lg);
  }

  .main-nav.open {
    display: flex;
  }
}