/* ============================================================
   SkipThink.ai — Styles
   Clean, professional, conversion-focused landing page.
   No framework dependencies.
   ============================================================ */

/* ---------- CSS Custom Properties ---------- */
:root {
  /* Brand palette */
  --color-navy:        #0f1b2d;
  --color-navy-light:  #1a2d47;
  --color-blue:        #2563eb;
  --color-blue-hover:  #1d4ed8;
  --color-blue-light:  #dbeafe;
  --color-accent:      #06b6d4;
  --color-white:       #ffffff;
  --color-gray-50:     #f8fafc;
  --color-gray-100:    #f1f5f9;
  --color-gray-200:    #e2e8f0;
  --color-gray-400:    #94a3b8;
  --color-gray-500:    #64748b;
  --color-gray-600:    #475569;
  --color-gray-700:    #334155;
  --color-gray-800:    #1e293b;
  --color-gray-900:    #0f172a;
  --color-success:     #10b981;

  /* Typography */
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI',
               Roboto, Oxygen, Ubuntu, Cantarell, 'Helvetica Neue', sans-serif;

  /* Spacing */
  --space-xs:  0.25rem;
  --space-sm:  0.5rem;
  --space-md:  1rem;
  --space-lg:  1.5rem;
  --space-xl:  2rem;
  --space-2xl: 3rem;
  --space-3xl: 4rem;
  --space-4xl: 6rem;

  /* Layout */
  --max-width: 1200px;
  --nav-height: 72px;

  /* Transitions */
  --transition-fast: 150ms ease;
  --transition-base: 250ms ease;

  /* Radius */
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
}


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

html {
  scroll-behavior: smooth;
  scroll-padding-top: var(--nav-height);
  font-size: 16px;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font-sans);
  line-height: 1.6;
  color: var(--color-gray-800);
  background: var(--color-white);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

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

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

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

ul {
  list-style: none;
}

h1, h2, h3, h4 {
  line-height: 1.2;
  color: var(--color-navy);
}


/* ---------- Utility ---------- */
.container {
  width: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--space-lg);
}


/* ---------- Buttons ---------- */
.btn {
  display: inline-block;
  padding: 0.75rem 1.75rem;
  font-size: 1rem;
  font-weight: 600;
  line-height: 1.4;
  border-radius: var(--radius-sm);
  border: 2px solid transparent;
  cursor: pointer;
  text-align: center;
  transition: background var(--transition-fast),
              color var(--transition-fast),
              border-color var(--transition-fast),
              box-shadow var(--transition-fast);
}

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

.btn-primary:hover {
  background: var(--color-blue-hover);
  border-color: var(--color-blue-hover);
  color: var(--color-white);
  box-shadow: 0 4px 14px rgba(37, 99, 235, 0.35);
}

.btn-secondary {
  background: transparent;
  color: var(--color-white);
  border-color: rgba(255, 255, 255, 0.5);
}

.btn-secondary:hover {
  background: rgba(255, 255, 255, 0.1);
  border-color: var(--color-white);
  color: var(--color-white);
}

.btn-outline {
  background: transparent;
  color: var(--color-blue);
  border-color: var(--color-blue);
}

.btn-outline:hover {
  background: var(--color-blue);
  color: var(--color-white);
}

.btn-lg {
  padding: 1rem 2.25rem;
  font-size: 1.125rem;
}


/* ============================================================
   NAVIGATION
   ============================================================ */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--nav-height);
  background: rgba(15, 27, 45, 0.95);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  z-index: 1000;
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
}

.nav-container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--space-lg);
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-logo {
  display: inline-flex;
  align-items: center;
}

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

.footer-logo-img {
  height: 28px;
  width: auto;
  opacity: 0.85;
}

.nav-logo:hover {
  opacity: 0.9;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: var(--space-xl);
}

.nav-links a {
  color: var(--color-gray-200);
  font-size: 0.9375rem;
  font-weight: 500;
  transition: color var(--transition-fast);
}

.nav-links a:hover {
  color: var(--color-white);
}

.nav-cta-free {
  background: #dc2626;
  color: var(--color-white) !important;
  padding: 0.5rem 1.25rem;
  border-radius: var(--radius-sm);
  font-weight: 600 !important;
  animation: pulse-glow 2s ease-in-out infinite;
}

.nav-cta-free:hover {
  background: #b91c1c;
  box-shadow: 0 4px 14px rgba(220, 38, 38, 0.4);
}

@keyframes pulse-glow {
  0%, 100% { box-shadow: 0 0 0 0 rgba(220, 38, 38, 0); }
  50% { box-shadow: 0 0 8px 2px rgba(220, 38, 38, 0.3); }
}

.nav-cta-btn {
  background: var(--color-blue);
  color: var(--color-white) !important;
  padding: 0.5rem 1.25rem;
  border-radius: var(--radius-sm);
  font-weight: 600 !important;
}

.nav-cta-btn:hover {
  background: var(--color-blue-hover);
}

/* Hamburger toggle (mobile) */
.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 6px;
  z-index: 1001;
}

.hamburger-line {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--color-white);
  border-radius: 2px;
  transition: transform var(--transition-base), opacity var(--transition-base);
}

.nav-toggle[aria-expanded="true"] .hamburger-line:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}
.nav-toggle[aria-expanded="true"] .hamburger-line:nth-child(2) {
  opacity: 0;
}
.nav-toggle[aria-expanded="true"] .hamburger-line:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}


/* ============================================================
   HERO
   ============================================================ */
.hero {
  padding-top: calc(var(--nav-height) + var(--space-4xl));
  padding-bottom: var(--space-4xl);
  background: linear-gradient(165deg, var(--color-navy) 0%, var(--color-navy-light) 100%);
  text-align: center;
  overflow: hidden;
  position: relative;
}

/* subtle grid pattern overlay */
.hero::before {
  content: '';
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(255,255,255,0.03) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255,255,255,0.03) 1px, transparent 1px);
  background-size: 60px 60px;
  pointer-events: none;
}

.hero-inner {
  position: relative;
  z-index: 1;
}

.hero-headline {
  font-size: clamp(2.25rem, 5vw, 3.75rem);
  font-weight: 800;
  color: var(--color-white);
  letter-spacing: -0.025em;
  margin-bottom: var(--space-lg);
}

.hero-you {
  text-decoration: underline;
  text-decoration-thickness: 3px;
  text-underline-offset: 4px;
}

.hero-subheadline {
  font-size: clamp(1.0625rem, 2vw, 1.25rem);
  color: var(--color-gray-400);
  max-width: 640px;
  margin: 0 auto var(--space-2xl);
  line-height: 1.7;
}

.hero-cta-group {
  display: flex;
  gap: var(--space-md);
  justify-content: center;
  flex-wrap: wrap;
}


/* ============================================================
   SECTIONS (shared)
   ============================================================ */
.section {
  padding: var(--space-4xl) 0;
}

.section-alt {
  background: var(--color-gray-50);
}

.section-title {
  font-size: clamp(1.75rem, 3.5vw, 2.5rem);
  font-weight: 800;
  text-align: center;
  margin-bottom: var(--space-md);
  letter-spacing: -0.02em;
}

.section-subtitle {
  text-align: center;
  color: var(--color-gray-600);
  max-width: 640px;
  margin: 0 auto var(--space-3xl);
  font-size: 1.0625rem;
  line-height: 1.7;
}


/* ============================================================
   PROBLEM SECTION
   ============================================================ */
.problem-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: var(--space-xl);
}

.problem-card {
  background: var(--color-white);
  border: 1px solid var(--color-gray-200);
  border-radius: var(--radius-md);
  padding: var(--space-2xl);
  text-align: center;
  transition: box-shadow var(--transition-base), transform var(--transition-base);
}

.problem-card:hover {
  box-shadow: 0 8px 30px rgba(0, 0, 0, 0.08);
  transform: translateY(-2px);
}

.problem-icon {
  font-size: 2.5rem;
  margin-bottom: var(--space-md);
}

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

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


/* ============================================================
   STEPS / HOW IT WORKS
   ============================================================ */
.steps-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: var(--space-xl);
  counter-reset: step-counter;
}

.step-card {
  text-align: center;
  padding: var(--space-2xl) var(--space-lg);
}

.step-number {
  width: 56px;
  height: 56px;
  border-radius: 50%;
  background: var(--color-blue);
  color: var(--color-white);
  font-size: 1.5rem;
  font-weight: 800;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto var(--space-lg);
}

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

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


/* ============================================================
   PRODUCTS
   ============================================================ */
.product-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: var(--space-xl);
}

.product-card {
  background: var(--color-white);
  border: 1px solid var(--color-gray-200);
  border-radius: var(--radius-md);
  padding: var(--space-2xl);
  position: relative;
  display: flex;
  flex-direction: column;
  transition: box-shadow var(--transition-base), transform var(--transition-base);
}

.product-card:hover {
  box-shadow: 0 8px 30px rgba(0, 0, 0, 0.08);
  transform: translateY(-2px);
}

.product-badge {
  position: absolute;
  top: var(--space-md);
  right: var(--space-md);
  background: var(--color-accent);
  color: var(--color-white);
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  padding: 0.25rem 0.75rem;
  border-radius: 100px;
}

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

.product-card p {
  color: var(--color-gray-600);
  font-size: 0.9375rem;
  line-height: 1.6;
  flex: 1;
  margin-bottom: var(--space-lg);
}


/* ============================================================
   PRICING
   ============================================================ */
.pricing-grid {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: var(--space-lg);
  align-items: stretch;
}

.pricing-card {
  background: var(--color-white);
  border: 1px solid var(--color-gray-200);
  border-radius: var(--radius-md);
  padding: var(--space-lg);
  text-align: center;
  position: relative;
  transition: box-shadow var(--transition-base);
  display: flex;
  flex-direction: column;
}

.pricing-card:hover {
  box-shadow: 0 8px 30px rgba(0, 0, 0, 0.08);
}

.pricing-card-featured {
  border-color: var(--color-blue);
  box-shadow: 0 4px 20px rgba(37, 99, 235, 0.15);
  transform: scale(1.03);
}

.pricing-popular-badge {
  position: absolute;
  top: -14px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--color-blue);
  color: var(--color-white);
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  padding: 0.25rem 1rem;
  border-radius: 100px;
  white-space: nowrap;
}

.pricing-tier {
  font-size: 1.25rem;
  font-weight: 700;
  margin-bottom: var(--space-sm);
}

.pricing-price {
  font-size: 2rem;
  font-weight: 800;
  color: var(--color-navy);
  margin-bottom: 0;
}

.pricing-unit {
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--color-gray-500);
}

.pricing-period {
  color: var(--color-gray-500);
  font-size: 0.875rem;
  margin-bottom: var(--space-lg);
}

.pricing-features {
  text-align: left;
  margin-bottom: var(--space-lg);
  flex: 1;
}

.pricing-features li {
  padding: 0.35rem 0;
  font-size: 0.8125rem;
  color: var(--color-gray-700);
  border-bottom: 1px solid var(--color-gray-100);
  padding-left: 1.35rem;
  position: relative;
}

.pricing-features li::before {
  content: '\2713';
  position: absolute;
  left: 0;
  color: var(--color-success);
  font-weight: 700;
}

.pricing-sample-link {
  display: block;
  font-size: 0.8125rem;
  color: var(--color-blue);
  margin-bottom: var(--space-md);
  transition: color var(--transition-fast);
}

.pricing-sample-link:hover {
  color: var(--color-blue-hover);
}

.pricing-tax {
  text-align: center;
  color: var(--color-gray-500);
  font-size: 0.8125rem;
  margin-top: var(--space-xl);
}

.pricing-footnote {
  text-align: center;
  color: var(--color-gray-500);
  font-size: 0.75rem;
  margin-top: var(--space-sm);
  max-width: 700px;
  margin-left: auto;
  margin-right: auto;
  line-height: 1.5;
}


/* ============================================================
   FAQ
   ============================================================ */
.faq-list {
  max-width: 740px;
  margin: 0 auto;
}

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

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

.faq-question {
  width: 100%;
  background: none;
  border: none;
  text-align: left;
  font-family: var(--font-sans);
  font-size: 1.0625rem;
  font-weight: 600;
  color: var(--color-navy);
  padding: var(--space-lg) 0;
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: var(--space-md);
  transition: color var(--transition-fast);
}

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

.faq-icon {
  font-size: 1.5rem;
  font-weight: 300;
  line-height: 1;
  flex-shrink: 0;
  transition: transform var(--transition-base);
}

.faq-item.active .faq-icon {
  transform: rotate(45deg);
}

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height var(--transition-base) ease,
              padding var(--transition-base) ease;
}

.faq-item.active .faq-answer {
  max-height: 300px;
  /* padding added via JS for smooth animation */
}

.faq-answer p {
  color: var(--color-gray-600);
  font-size: 0.9375rem;
  line-height: 1.7;
  padding-bottom: var(--space-lg);
}


/* ============================================================
   BOTTOM CTA
   ============================================================ */
.section-cta {
  background: linear-gradient(165deg, var(--color-navy) 0%, var(--color-navy-light) 100%);
  text-align: center;
  padding: var(--space-4xl) 0;
}

.cta-headline {
  color: var(--color-white);
  font-size: clamp(1.75rem, 3.5vw, 2.5rem);
  margin-bottom: var(--space-md);
}

.cta-subtext {
  color: var(--color-gray-400);
  font-size: 1.125rem;
  margin-bottom: var(--space-2xl);
}


/* ============================================================
   FOOTER
   ============================================================ */
.site-footer {
  background: var(--color-gray-900);
  padding: var(--space-3xl) 0 var(--space-xl);
}

.footer-inner {
  display: grid;
  grid-template-columns: 1.5fr 2fr;
  gap: var(--space-3xl);
}

.footer-tagline {
  color: var(--color-gray-500);
  margin-top: var(--space-sm);
  font-size: 0.9375rem;
}

.footer-links {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-xl);
}

.footer-col h4 {
  color: var(--color-gray-200);
  font-size: 0.875rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  margin-bottom: var(--space-md);
}

.footer-col a {
  display: block;
  color: var(--color-gray-500);
  font-size: 0.9375rem;
  padding: 0.3rem 0;
  transition: color var(--transition-fast);
}

.footer-col a:hover {
  color: var(--color-white);
}

.footer-bottom {
  grid-column: 1 / -1;
  border-top: 1px solid var(--color-gray-800);
  padding-top: var(--space-xl);
  margin-top: var(--space-xl);
}

.footer-bottom p {
  color: var(--color-gray-500);
  font-size: 0.8125rem;
}


/* ============================================================
   RESPONSIVE  — Tablet
   ============================================================ */
@media (max-width: 900px) {
  .footer-inner {
    grid-template-columns: 1fr;
  }

  .pricing-grid {
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: var(--space-md);
  }

  .pricing-card-featured {
    transform: none;
  }
}


/* ============================================================
   RESPONSIVE  — Mobile
   ============================================================ */
@media (max-width: 768px) {
  /* Nav */
  .nav-toggle {
    display: flex;
  }

  .nav-links {
    position: fixed;
    top: 0;
    right: 0;
    width: 280px;
    height: 100vh;
    background: var(--color-navy);
    flex-direction: column;
    align-items: flex-start;
    padding: calc(var(--nav-height) + var(--space-xl)) var(--space-xl) var(--space-xl);
    gap: var(--space-md);
    transform: translateX(100%);
    transition: transform var(--transition-base);
    box-shadow: -4px 0 20px rgba(0, 0, 0, 0.3);
  }

  .nav-links.open {
    transform: translateX(0);
  }

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

  /* Hero */
  .hero {
    padding-top: calc(var(--nav-height) + var(--space-2xl));
    padding-bottom: var(--space-2xl);
  }

  /* Sections */
  .section {
    padding: var(--space-3xl) 0;
  }

  /* Pricing */
  .pricing-grid {
    grid-template-columns: 1fr;
    max-width: 400px;
    margin: 0 auto;
  }

  /* Products */
  .product-grid {
    grid-template-columns: 1fr;
  }

  /* Footer */
  .footer-links {
    grid-template-columns: 1fr 1fr;
  }
}

@media (max-width: 480px) {
  .footer-links {
    grid-template-columns: 1fr;
  }

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

  .hero-cta-group .btn {
    width: 100%;
    max-width: 300px;
  }
}