/* ============================================================
   ThinkAI LLC — Design System
   ============================================================ */



/* --- Variables --- */
:root {
  --bg: #f4f8fd;
  --surface: #ffffff;
  --surface-alt: #edf3fa;
  --border: rgba(23, 116, 184, 0.14);
  --text: #0e2a44;
  --muted: #4e6882;
  --primary: #1774b8;
  --primary-dark: #125d96;
  --primary-ink: #ffffff;
  --accent: #1eb6f0;
  --tag-bg: rgba(23, 116, 184, 0.1);
  --tag-text: #1058a0;
  --shadow-sm: 0 2px 8px rgba(23, 116, 184, 0.08);
  --shadow-md: 0 8px 28px rgba(23, 116, 184, 0.12);
  --shadow-lg: 0 20px 60px rgba(23, 116, 184, 0.15);
  --radius: 14px;
  --radius-sm: 8px;
  --max-w: 1100px;
}

/* --- Reset --- */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  font-size: 16px;
  line-height: 1.6;
  color: var(--text);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
}

/* --- Typography --- */
h1, h2, h3, h4 { font-family: 'Inter', sans-serif; font-weight: 700; line-height: 1.2; }
h1 { font-size: clamp(2rem, 5vw, 3.25rem); }
h2 { font-size: clamp(1.6rem, 3.5vw, 2.25rem); }
h3 { font-size: 1.2rem; font-weight: 600; font-family: 'Inter', sans-serif; }
p { color: var(--muted); }
a { color: inherit; text-decoration: none; }

/* --- Layout utilities --- */
.section-inner, .header-inner, .footer-inner {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 1.5rem;
}

/* ============================================================
   HEADER
   ============================================================ */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(244, 248, 253, 0.92);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
}

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

.brand {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  text-decoration: none;
}

.brand-logo {
  width: 36px;
  height: 36px;
  border-radius: 8px;
  object-fit: cover;
  flex-shrink: 0;
}

.brand-name {
  font-family: 'Inter', sans-serif;
  font-weight: 700;
  font-size: 1rem;
  color: var(--text);
  letter-spacing: -0.01em;
}

.site-nav {
  display: flex;
  align-items: center;
  gap: 0.25rem;
}

.site-nav a {
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--muted);
  padding: 0.4rem 0.75rem;
  border-radius: var(--radius-sm);
  transition: color 0.15s, background 0.15s;
}

.site-nav a:hover { color: var(--text); background: var(--surface-alt); }

.site-nav .nav-cta {
  background: var(--primary);
  color: var(--primary-ink);
  padding: 0.4rem 1rem;
  border-radius: 100px;
}

.site-nav .nav-cta:hover { background: var(--primary-dark); color: var(--primary-ink); }

/* ============================================================
   HERO
   ============================================================ */
.hero {
  padding: 5rem 1.5rem 4rem;
}

.hero-inner {
  max-width: var(--max-w);
  margin: 0 auto;
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 3rem;
  align-items: center;
}

.hero-center {
  grid-template-columns: 1fr;
  text-align: center;
  max-width: 640px;
}

.hero-compact { padding: 3.5rem 1.5rem 3rem; }

.kicker {
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--primary);
  margin-bottom: 1rem;
}

.hero-text h1 { color: var(--text); margin-bottom: 1rem; }
.hero-center h1 { color: var(--text); margin-bottom: 1rem; }
.hero-sub { font-size: 1.1rem; color: var(--muted); margin-bottom: 2rem; max-width: 520px; }
.hero-center .hero-sub { margin-left: auto; margin-right: auto; }

.hero-actions { display: flex; gap: 0.75rem; flex-wrap: wrap; }
.hero-center .hero-actions { justify-content: center; }

.hero-logo-wrap { flex-shrink: 0; }

.hero-logo {
  width: 220px;
  height: 220px;
  border-radius: 24px;
  object-fit: cover;
  box-shadow: var(--shadow-lg), 0 0 0 1px var(--border);
}

/* ============================================================
   BUTTONS
   ============================================================ */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  font-size: 0.9rem;
  font-weight: 600;
  padding: 0.65rem 1.4rem;
  border-radius: 100px;
  border: none;
  cursor: pointer;
  transition: transform 0.15s, box-shadow 0.15s, background 0.15s;
  text-decoration: none;
  white-space: nowrap;
}

.btn:hover { transform: translateY(-1px); }

.btn-primary {
  background: var(--primary);
  color: var(--primary-ink);
  box-shadow: 0 4px 14px rgba(23, 116, 184, 0.3);
}

.btn-primary:hover {
  background: var(--primary-dark);
  box-shadow: 0 6px 20px rgba(23, 116, 184, 0.4);
}

.btn-ghost {
  background: transparent;
  color: var(--primary);
  border: 1.5px solid var(--primary);
}

.btn-ghost:hover { background: var(--tag-bg); }

/* ============================================================
   SECTIONS
   ============================================================ */
.section { padding: 5rem 1.5rem; }
.section-alt { background: var(--surface-alt); }

.section-title {
  color: var(--text);
  margin-bottom: 0.5rem;
}

.section-sub {
  color: var(--muted);
  font-size: 1.05rem;
  margin-bottom: 3rem;
  max-width: 560px;
}

/* ============================================================
   SERVICE CARDS
   ============================================================ */
.cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(270px, 1fr));
  gap: 1.25rem;
}

.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.75rem;
  box-shadow: var(--shadow-sm);
  transition: box-shadow 0.2s, transform 0.2s;
}

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

.card-icon { font-size: 1.75rem; margin-bottom: 1rem; }

.card h3 { color: var(--text); margin-bottom: 0.5rem; }
.card p { font-size: 0.92rem; }

/* ============================================================
   PRODUCT CARDS
   ============================================================ */
.products {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 1.25rem;
}

.product-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 2rem;
  box-shadow: var(--shadow-sm);
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  transition: box-shadow 0.2s, transform 0.2s;
}

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

.product-featured {
  border-color: var(--primary);
  box-shadow: 0 0 0 1px rgba(23, 116, 184, 0.2), var(--shadow-sm);
}

.product-meta { display: flex; align-items: center; gap: 0.5rem; }

.product-card h3 { color: var(--text); }
.product-card p { font-size: 0.92rem; flex: 1; }

.product-link {
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--primary);
  text-decoration: none;
  transition: color 0.15s;
}

.product-link:hover { color: var(--primary-dark); }

/* ============================================================
   TAG / PILL
   ============================================================ */
.tag {
  display: inline-block;
  font-size: 0.72rem;
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  background: var(--tag-bg);
  color: var(--tag-text);
  padding: 0.2rem 0.6rem;
  border-radius: 100px;
}

/* ============================================================
   ABOUT SECTION
   ============================================================ */
.about-inner { max-width: 720px; }

.about-lead {
  font-size: 1.15rem;
  color: var(--text);
  margin-bottom: 1rem;
  line-height: 1.6;
}

.about-text p {
  color: var(--muted);
  margin-bottom: 1rem;
  line-height: 1.7;
}

.about-text .btn-secondary {
  display: inline-block;
  margin-top: 0.5rem;
  padding: 0.65rem 1.4rem;
  border: 2px solid var(--primary);
  color: var(--primary);
  border-radius: 8px;
  font-weight: 600;
  font-size: 0.95rem;
  text-decoration: none;
  transition: background 0.18s, color 0.18s;
}
.about-text .btn-secondary:hover {
  background: var(--primary);
  color: #fff;
}

/* ============================================================
   CONTACT SECTION
   ============================================================ */
.contact-inner {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 3rem;
  align-items: center;
}

.contact-logo {
  width: 100px;
  height: 100px;
  border-radius: var(--radius);
  object-fit: cover;
  box-shadow: var(--shadow-md);
}

.contact-text h2 { color: var(--text); margin-bottom: 0.75rem; padding-bottom: 0.3em; }
.contact-text p { margin-bottom: 1.5rem; }

/* ============================================================
   APP DETAIL (mobile-apps page)
   ============================================================ */
.app-detail {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 3rem;
  align-items: center;
}

.app-detail-text { max-width: 600px; }
.app-detail-text h2 { color: var(--text); margin: 0.75rem 0 1rem; }

.app-desc { font-size: 1.05rem; margin-bottom: 1.5rem; }

.app-features {
  list-style: none;
  margin-bottom: 2rem;
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
}

.app-features li {
  font-size: 0.92rem;
  color: var(--muted);
  padding-left: 1.25rem;
  position: relative;
}

.app-features li::before {
  content: '✓';
  position: absolute;
  left: 0;
  color: var(--primary);
  font-weight: 700;
}

.store-buttons { display: flex; gap: 0.75rem; flex-wrap: wrap; }

.app-icon-placeholder {
  width: 140px;
  height: 140px;
  border-radius: 28px;
  background: linear-gradient(135deg, var(--primary), var(--accent));
  color: white;
  font-family: 'Inter', sans-serif;
  font-weight: 700;
  font-size: 2rem;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: var(--shadow-md);
  flex-shrink: 0;
}

/* Web product note */
.web-product-note {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 2rem;
  max-width: 560px;
}

.web-product-note h3 { color: var(--text); margin: 0.75rem 0 0.5rem; }
.web-product-note p { font-size: 0.95rem; }
.web-product-note a { color: var(--primary); font-weight: 500; text-decoration: underline; }

/* ============================================================
   FOOTER
   ============================================================ */
.site-footer {
  border-top: 1px solid var(--border);
  background: var(--surface);
  padding: 2rem 1.5rem;
}

.footer-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  flex-wrap: wrap;
}

.site-footer span { font-size: 0.875rem; color: var(--muted); }

.site-footer nav { display: flex; gap: 1.5rem; flex-wrap: wrap; }

.site-footer nav a {
  font-size: 0.875rem;
  color: var(--muted);
  transition: color 0.15s;
}

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

/* ============================================================
   RESPONSIVE
   ============================================================ */
@media (max-width: 768px) {
  .hero-inner {
    grid-template-columns: 1fr;
    gap: 2rem;
  }

  .hero-logo-wrap { order: -1; }
  .hero-logo { width: 120px; height: 120px; }

  .contact-inner {
    grid-template-columns: 1fr;
    gap: 1.5rem;
    text-align: center;
  }

  .contact-brand { display: flex; justify-content: center; }
  .contact-logo { width: 72px; height: 72px; }

  .app-detail {
    grid-template-columns: 1fr;
    gap: 1.5rem;
  }

  .app-detail-visual { display: flex; justify-content: center; }

  .site-nav { gap: 0; }
  .site-nav a { padding: 0.4rem 0.5rem; font-size: 0.8rem; }
  .brand-name { display: none; }

  .section { padding: 3.5rem 1.5rem; }
  .hero { padding: 3rem 1.5rem 2.5rem; }
}

@media (max-width: 480px) {
  .site-nav .nav-cta { display: none; }
  .footer-inner { flex-direction: column; align-items: flex-start; gap: 1rem; }
}

/* ============================================================
   PRODUCT ICONS
   ============================================================ */
.product-icon {
  width: 44px;
  height: 44px;
  border-radius: 10px;
  object-fit: cover;
  flex-shrink: 0;
}

.product-icon-svg {
  object-fit: contain;
  background: transparent;
  width: 40px;
  height: 48px;
}

/* ============================================================
   CONTACT FORM
   ============================================================ */
.contact-form {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  width: 100%;
  max-width: 480px;
}

.contact-form input,
.contact-form textarea {
  width: 100%;
  padding: 0.7rem 1rem;
  border: 1.5px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--surface);
  color: var(--text);
  font-family: inherit;
  font-size: 0.95rem;
  transition: border-color 0.15s, box-shadow 0.15s;
  outline: none;
}

.contact-form input:focus,
.contact-form textarea:focus {
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(23, 116, 184, 0.12);
}

.contact-form textarea { resize: vertical; min-height: 110px; }

.contact-form input::placeholder,
.contact-form textarea::placeholder { color: var(--muted); opacity: 0.7; }

.contact-form .btn { align-self: flex-start; }
.contact-form .btn:disabled { opacity: 0.6; cursor: not-allowed; }

.form-feedback { font-size: 0.9rem; margin-top: 0.25rem; min-height: 1.2em; }
.form-feedback.success { color: #1a9e5c; }
.form-feedback.error { color: #d94f4f; }

/* ============================================================
   APP ICON (real image, mobile-apps page)
   ============================================================ */
.app-icon {
  width: 140px;
  height: 140px;
  border-radius: 28px;
  object-fit: cover;
  box-shadow: var(--shadow-md);
  flex-shrink: 0;
}

/* ============================================================
   STORE BADGES
   ============================================================ */
.store-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.65rem;
  padding: 0.55rem 1.25rem 0.55rem 1rem;
  border-radius: 10px;
  text-decoration: none;
  transition: transform 0.15s, opacity 0.15s;
  white-space: nowrap;
}

.store-badge:hover { transform: translateY(-1px); opacity: 0.88; }

.store-badge svg { flex-shrink: 0; }

.store-badge-text {
  display: flex;
  flex-direction: column;
  line-height: 1.15;
}

.store-badge-text small {
  font-size: 0.62rem;
  font-weight: 500;
  letter-spacing: 0.03em;
}

.store-badge-text strong {
  font-size: 1.05rem;
  font-weight: 700;
  font-family: 'Inter', sans-serif;
}

.store-apple {
  background: #000000;
  color: #ffffff;
}

.store-google {
  background: #ffffff;
  color: #202124;
  border: 1px solid #dadce0;
  box-shadow: 0 1px 4px rgba(0, 0, 0, 0.12);
}