/* ============================================================
   BotsChat Landing Page — Light & Dark Theme
   ============================================================ */

/* ---------- CSS Variables ---------- */
:root {
  /* Shared */
  --font: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --max-w: 1120px;
  --radius: 12px;
  --radius-lg: 20px;
  --transition: 0.25s ease;

  /* Accent */
  --accent: #6366f1;
  --accent-hover: #4f46e5;
  --accent-soft: rgba(99, 102, 241, 0.12);
}

/* Light theme */
[data-theme="light"] {
  --bg: #ffffff;
  --bg-alt: #f8f9fc;
  --bg-card: #ffffff;
  --bg-card-hover: #f3f4f8;
  --text: #1a1a2e;
  --text-secondary: #5a5a7a;
  --text-muted: #9191ab;
  --border: #e5e5ef;
  --border-light: #ededf5;
  --shadow-card: 0 1px 3px rgba(0,0,0,0.06), 0 4px 16px rgba(0,0,0,0.04);
  --shadow-screenshot: 0 8px 40px rgba(0,0,0,0.12), 0 2px 8px rgba(0,0,0,0.06);
  --nav-bg: rgba(255,255,255,0.85);
  --nav-border: rgba(0,0,0,0.06);
  --code-bg: #f0f0f8;
  --hero-gradient: linear-gradient(160deg, #f8f9fc 0%, #eef0ff 50%, #f8f9fc 100%);
  --feature-label-bg: var(--accent-soft);
  --feature-label-color: var(--accent);
  --step-num-bg: var(--accent);
  --step-num-color: #fff;
}

/* Dark theme */
[data-theme="dark"] {
  --bg: #0b0f1a;
  --bg-alt: #111827;
  --bg-card: #161d2e;
  --bg-card-hover: #1c2538;
  --text: #e8e8f0;
  --text-secondary: #a0a0ba;
  --text-muted: #6b6b85;
  --border: #232b3e;
  --border-light: #1e2636;
  --shadow-card: 0 1px 3px rgba(0,0,0,0.3), 0 4px 16px rgba(0,0,0,0.2);
  --shadow-screenshot: 0 8px 40px rgba(0,0,0,0.5), 0 2px 8px rgba(0,0,0,0.3);
  --nav-bg: rgba(11,15,26,0.88);
  --nav-border: rgba(255,255,255,0.06);
  --code-bg: #1e2636;
  --hero-gradient: linear-gradient(160deg, #0b0f1a 0%, #111b2e 50%, #0b0f1a 100%);
  --feature-label-bg: rgba(99, 102, 241, 0.15);
  --feature-label-color: #818cf8;
  --step-num-bg: #6366f1;
  --step-num-color: #fff;
}

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

html {
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
}

body {
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  line-height: 1.7;
  transition: background var(--transition), color var(--transition);
}

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

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

/* ---------- Layout ---------- */
.container {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 24px;
}

.section-header {
  text-align: center;
  max-width: 640px;
  margin: 0 auto 64px;
}
.section-header h2 {
  font-size: 2.25rem;
  font-weight: 800;
  letter-spacing: -0.02em;
  margin-bottom: 12px;
}
.section-header p {
  font-size: 1.125rem;
  color: var(--text-secondary);
}

/* ---------- Top Banner ---------- */
.top-banner {
  background: var(--accent);
  color: #fff;
  text-align: center;
  padding: 8px 0;
  font-size: 0.85rem;
  font-weight: 500;
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 101;
}
.top-banner .container {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
}
.top-banner a {
  color: #fff;
  font-weight: 700;
  display: inline-flex;
  align-items: center;
  gap: 4px;
  text-decoration: underline;
  text-underline-offset: 2px;
}
.top-banner a:hover {
  color: #fff;
  opacity: 0.9;
}

/* ---------- Navigation ---------- */
.nav {
  position: fixed;
  top: 36px;
  left: 0;
  right: 0;
  z-index: 100;
  background: var(--nav-bg);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--nav-border);
  transition: background var(--transition);
}
.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}
.nav-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  font-size: 1.125rem;
  color: var(--text);
}
.nav-logo:hover { color: var(--text); }

.logo-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 34px;
  height: 34px;
  border-radius: 8px;
  background: var(--accent);
  color: #fff;
  font-size: 0.75rem;
  font-weight: 800;
  letter-spacing: 0.02em;
}
.logo-icon-sm {
  width: 26px;
  height: 26px;
  font-size: 0.6rem;
  border-radius: 6px;
}
.logo-icon-img {
  width: 34px;
  height: 34px;
  min-width: 34px;
  min-height: 34px;
  max-width: 34px;
  max-height: 34px;
  border-radius: 8px;
  object-fit: contain;
}
.logo-icon-img-sm {
  width: 26px;
  height: 26px;
  min-width: 26px;
  min-height: 26px;
  max-width: 26px;
  max-height: 26px;
  border-radius: 6px;
}
[data-theme="dark"] .logo-icon-img {
  filter: invert(1);
}
.logo-text { color: var(--text); }

.nav-links {
  display: flex;
  align-items: center;
  gap: 28px;
}
.nav-links a:not(.btn) {
  color: var(--text-secondary);
  font-size: 0.9rem;
  font-weight: 500;
}
.nav-links a:not(.btn):hover { color: var(--text); }

.nav-mobile-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
}
.nav-mobile-toggle span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--text);
  border-radius: 2px;
  transition: var(--transition);
}

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 24px;
  border-radius: 10px;
  font-size: 0.95rem;
  font-weight: 600;
  cursor: pointer;
  border: none;
  transition: all var(--transition);
  text-decoration: none;
}
.btn-primary {
  background: var(--accent);
  color: #fff;
}
.btn-primary:hover {
  background: var(--accent-hover);
  color: #fff;
  transform: translateY(-1px);
  box-shadow: 0 4px 16px rgba(99,102,241,0.3);
}
.btn-outline {
  background: transparent;
  color: var(--text);
  border: 1.5px solid var(--border);
}
.btn-outline:hover {
  border-color: var(--accent);
  color: var(--accent);
  transform: translateY(-1px);
}
.btn-sm {
  padding: 8px 18px;
  font-size: 0.85rem;
  border-radius: 8px;
}

/* ---------- Theme Toggle ---------- */
.theme-toggle {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  border-radius: 10px;
  border: 1.5px solid var(--border);
  background: transparent;
  color: var(--text-secondary);
  cursor: pointer;
  transition: all var(--transition);
}
.theme-toggle:hover {
  border-color: var(--accent);
  color: var(--accent);
}
[data-theme="light"] .icon-sun { display: none; }
[data-theme="light"] .icon-moon { display: block; }
[data-theme="dark"] .icon-sun { display: block; }
[data-theme="dark"] .icon-moon { display: none; }

/* ---------- Hero ---------- */
.hero {
  padding: 176px 0 80px;
  background: var(--hero-gradient);
  text-align: center;
  transition: background var(--transition);
}
.hero-badge {
  display: inline-block;
  padding: 6px 18px;
  border-radius: 100px;
  background: var(--accent-soft);
  color: var(--feature-label-color);
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.02em;
  margin-bottom: 28px;
}
.hero-title {
  font-size: clamp(2.25rem, 5vw, 3.5rem);
  font-weight: 800;
  letter-spacing: -0.03em;
  line-height: 1.15;
  margin-bottom: 20px;
}
.hero-title em {
  font-style: normal;
  background: linear-gradient(135deg, var(--accent), #a78bfa);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}
.hero-subtitle {
  max-width: 620px;
  margin: 0 auto 36px;
  font-size: 1.15rem;
  color: var(--text-secondary);
  line-height: 1.7;
}
.hero-cta {
  display: flex;
  justify-content: center;
  gap: 14px;
  flex-wrap: wrap;
}
.hero-screenshot {
  margin-top: 64px;
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-screenshot);
  border: 1px solid var(--border);
  transition: box-shadow var(--transition), border var(--transition);
}
.hero-screenshot img {
  width: 100%;
}

/* ---------- Advantages ---------- */
.advantages {
  padding: 100px 0;
}
.advantage-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}
.advantage-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 36px 28px;
  transition: all var(--transition);
}
.advantage-card:hover {
  background: var(--bg-card-hover);
  border-color: var(--accent);
  transform: translateY(-2px);
  box-shadow: var(--shadow-card);
}
.advantage-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 56px;
  height: 56px;
  border-radius: 14px;
  background: var(--accent-soft);
  color: var(--accent);
  margin-bottom: 20px;
}
[data-theme="dark"] .advantage-icon {
  color: #818cf8;
}
.advantage-card h3 {
  font-size: 1.2rem;
  font-weight: 700;
  margin-bottom: 10px;
}
.advantage-card p {
  color: var(--text-secondary);
  font-size: 0.95rem;
  line-height: 1.7;
}

/* ---------- Features ---------- */
.features {
  padding: 100px 0;
  background: var(--bg-alt);
  transition: background var(--transition);
}
.feature-row {
  display: grid;
  grid-template-columns: 1fr 1.2fr;
  gap: 56px;
  align-items: center;
  margin-bottom: 96px;
}
.feature-row:last-child { margin-bottom: 0; }
.feature-row.reverse { grid-template-columns: 1.2fr 1fr; }
.feature-row.reverse .feature-text { order: 2; }
.feature-row.reverse .feature-image { order: 1; }

.feature-label {
  display: inline-block;
  padding: 4px 14px;
  border-radius: 100px;
  background: var(--feature-label-bg);
  color: var(--feature-label-color);
  font-size: 0.78rem;
  font-weight: 600;
  letter-spacing: 0.03em;
  text-transform: uppercase;
  margin-bottom: 14px;
}
.feature-text h3 {
  font-size: 1.65rem;
  font-weight: 800;
  letter-spacing: -0.02em;
  line-height: 1.25;
  margin-bottom: 14px;
}
.feature-text p {
  color: var(--text-secondary);
  font-size: 1rem;
  margin-bottom: 20px;
}
.feature-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 10px;
}
.feature-list li {
  position: relative;
  padding-left: 24px;
  color: var(--text-secondary);
  font-size: 0.95rem;
}
.feature-list li::before {
  content: '';
  position: absolute;
  left: 0;
  top: 9px;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--accent);
}
.feature-list li strong {
  color: var(--text);
}

.feature-image {
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-screenshot);
  border: 1px solid var(--border);
  transition: all var(--transition);
}
.feature-image:hover {
  transform: scale(1.01);
  box-shadow: var(--shadow-screenshot), 0 0 0 2px var(--accent);
}

code {
  background: var(--code-bg);
  padding: 2px 7px;
  border-radius: 5px;
  font-size: 0.88em;
  font-family: 'SF Mono', 'Fira Code', monospace;
  transition: background var(--transition);
}

/* ---------- Architecture ---------- */
.architecture {
  padding: 100px 0;
}
.arch-content {
  display: grid;
  grid-template-columns: 1.3fr 1fr;
  gap: 56px;
  align-items: center;
}
.arch-image {
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-screenshot);
  border: 1px solid var(--border);
}
.arch-steps {
  display: flex;
  flex-direction: column;
  gap: 32px;
}
.arch-step {
  display: flex;
  gap: 18px;
  align-items: flex-start;
}
.step-num {
  flex-shrink: 0;
  width: 40px;
  height: 40px;
  border-radius: 12px;
  background: var(--step-num-bg);
  color: var(--step-num-color);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 800;
  font-size: 1rem;
}
.step-text h4 {
  font-size: 1.05rem;
  font-weight: 700;
  margin-bottom: 6px;
}
.step-text p {
  color: var(--text-secondary);
  font-size: 0.92rem;
}

/* ---------- Coming Soon ---------- */
.coming-soon {
  padding: 100px 0;
  background: var(--bg-alt);
  transition: background var(--transition);
}
.coming-soon-inner {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 56px;
  align-items: center;
}
.coming-soon-text h2 {
  font-size: 2rem;
  font-weight: 800;
  letter-spacing: -0.02em;
  margin-bottom: 14px;
}
.coming-soon-text p {
  color: var(--text-secondary);
  font-size: 1.05rem;
  line-height: 1.7;
}
.coming-soon-platforms {
  display: flex;
  gap: 20px;
  justify-content: center;
}
.platform-card {
  flex: 1;
  max-width: 200px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 10px;
  padding: 36px 24px;
  border-radius: var(--radius);
  border: 1.5px dashed var(--border);
  background: var(--bg-card);
  color: var(--text-muted);
  transition: all var(--transition);
}
.platform-card:hover {
  border-color: var(--accent);
  color: var(--accent);
  transform: translateY(-2px);
  box-shadow: var(--shadow-card);
}
[data-theme="dark"] .platform-card:hover {
  color: #818cf8;
  border-color: #818cf8;
}
.platform-card svg {
  opacity: 0.7;
  transition: opacity var(--transition);
}
.platform-card:hover svg {
  opacity: 1;
}
.platform-name {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--text);
}
.platform-status {
  font-size: 0.78rem;
  font-weight: 600;
  letter-spacing: 0.03em;
  text-transform: uppercase;
  padding: 3px 12px;
  border-radius: 100px;
  background: var(--accent-soft);
  color: var(--feature-label-color);
}

@media (max-width: 900px) {
  .coming-soon-inner {
    grid-template-columns: 1fr;
    text-align: center;
  }
  .coming-soon-platforms {
    justify-content: center;
  }
}

@media (max-width: 640px) {
  .coming-soon { padding: 64px 0; }
  .coming-soon-platforms {
    flex-direction: column;
    align-items: center;
  }
  .platform-card { max-width: 240px; width: 100%; }
}

/* ---------- CTA ---------- */
.cta {
  padding: 100px 0;
  background: var(--bg-alt);
  text-align: center;
  transition: background var(--transition);
}
.cta h2 {
  font-size: 2rem;
  font-weight: 800;
  letter-spacing: -0.02em;
  margin-bottom: 14px;
}
.cta p {
  color: var(--text-secondary);
  font-size: 1.1rem;
  margin-bottom: 32px;
}

/* ---------- Footer ---------- */
.footer {
  padding: 28px 0;
  border-top: 1px solid var(--border);
  transition: border var(--transition);
}
.footer-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 16px;
}
.footer-left {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 0.85rem;
  color: var(--text-muted);
}
.footer-right {
  display: flex;
  gap: 24px;
}
.footer-right a {
  color: var(--text-muted);
  font-size: 0.85rem;
}
.footer-right a:hover { color: var(--accent); }

/* ---------- Responsive ---------- */
@media (max-width: 900px) {
  .advantage-grid {
    grid-template-columns: 1fr;
  }
  .feature-row,
  .feature-row.reverse {
    grid-template-columns: 1fr;
    gap: 32px;
  }
  .feature-row.reverse .feature-text { order: 1; }
  .feature-row.reverse .feature-image { order: 2; }
  .arch-content {
    grid-template-columns: 1fr;
  }
  .section-header h2 {
    font-size: 1.75rem;
  }
  .feature-text h3 {
    font-size: 1.35rem;
  }
}

@media (max-width: 640px) {
  .nav-links {
    display: none;
    position: absolute;
    top: 64px;
    left: 0;
    right: 0;
    background: var(--nav-bg);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    flex-direction: column;
    padding: 20px 24px;
    gap: 16px;
    border-bottom: 1px solid var(--nav-border);
  }
  .nav-links.open { display: flex; }
  .nav-mobile-toggle { display: flex; }

  .hero { padding: 146px 0 60px; }
  .hero-title { font-size: 1.85rem; }
  .hero-subtitle { font-size: 1rem; }
  .hero-screenshot { margin-top: 40px; }

  .advantages, .features, .architecture, .cta { padding: 64px 0; }
  .feature-row { margin-bottom: 64px; }

  .hero-cta {
    flex-direction: column;
    align-items: center;
  }
  .btn { width: 100%; max-width: 280px; justify-content: center; }

  .footer-inner {
    flex-direction: column;
    text-align: center;
  }
}

/* ---------- Animations ---------- */
@media (prefers-reduced-motion: no-preference) {
  .advantage-card,
  .feature-image,
  .arch-step {
    opacity: 0;
    transform: translateY(24px);
    transition: opacity 0.5s ease, transform 0.5s ease, background var(--transition), border-color var(--transition), box-shadow var(--transition);
  }
  .advantage-card.visible,
  .feature-image.visible,
  .arch-step.visible {
    opacity: 1;
    transform: translateY(0);
  }
}