/* =========================
   BASE
========================= */
* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  font-family: Inter, system-ui, -apple-system, BlinkMacSystemFont, sans-serif;
}

body {
  color: #1f2937;
  background: #ffffff;
  line-height: 1.6;
}

a {
  text-decoration: none;
  color: inherit;
}

.container {
  max-width: 1200px;
  margin: auto;
  padding: 0 24px;
}

.center {
  text-align: center;
}

/* =========================
   NAVBAR
========================= */
.navbar {
  background: #ffffff;
  border-bottom: 1px solid #e5e7eb;
  position: sticky;
  top: 0;
  z-index: 100;
}

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

.logo {
  font-size: 22px;
  font-weight: 700;
  color: #0ea5e9;
}

nav a {
  margin-left: 22px;
  font-weight: 500;
  color: #374151;
}

nav a.active {
  color: #0ea5e9;
  border-bottom: 2px solid #0ea5e9;
  padding-bottom: 4px;
}

.btn-primary {
  background: #0ea5e9;
  color: #ffffff;
  padding: 10px 18px;
  border-radius: 10px;
  font-weight: 600;
}

.btn-primary.large {
  font-size: 18px;
  padding: 14px 30px;
}

.btn-link {
  color: #0ea5e9;
  font-weight: 500;
}

.nav-toggle {
  display: none;
  font-size: 26px;
  background: none;
  border: none;
  cursor: pointer;
}

/* =========================
   HERO
========================= */
.hero {
  min-height: 90vh;
  display: flex;
  align-items: center;
  padding: 120px 0;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.2fr 0.8fr;
  gap: 60px;
}

.hero h1 {
  font-size: 58px;
  line-height: 1.1;
  letter-spacing: -0.02em;
}

.subtitle {
  font-size: 20px;
  color: #4b5563;
  margin: 24px 0;
  max-width: 560px;
}

.hero-points {
  list-style: none;
  margin: 24px 0;
}

.hero-points li {
  margin-bottom: 10px;
}

.hero-actions {
  margin-top: 30px;
  display: flex;
  gap: 22px;
  align-items: center;
}

.note {
  display: block;
  margin-top: 12px;
  color: #6b7280;
}

/* HERO VISUAL */
.hero-visual {
  display: flex;
  justify-content: center;
  align-items: center;
}

.robot-box {
  width: 360px;
  height: 360px;
  border-radius: 32px;
  background: radial-gradient(circle at top left, #38bdf8, #0ea5e9 65%);
  box-shadow:
    0 40px 80px rgba(14,165,233,0.35),
    inset 0 0 40px rgba(255,255,255,0.15);
  color: #ffffff;
  font-weight: 600;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  animation: float 6s ease-in-out infinite;
}

@keyframes float {
  0%,100% { transform: translateY(0); }
  50% { transform: translateY(-18px); }
}

/* =========================
   SECTIONS
========================= */
.section {
  padding: 120px 0;
}

.section.light {
  background: #f9fafb;
}

.section h2 {
  font-size: 42px;
  margin-bottom: 40px;
}

/* =========================
   FEATURES
========================= */
.features {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 40px;
}

.feature {
  padding: 30px;
  border-radius: 16px;
  background: #ffffff;
  border: 1px solid #e5e7eb;
  transition: transform .2s ease, box-shadow .2s ease;
}

.feature:hover {
  transform: translateY(-6px);
  box-shadow: 0 12px 30px rgba(0,0,0,.08);
}

.feature h3 {
  margin-bottom: 10px;
}

/* =========================
   HOW IT WORKS
========================= */
.steps {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 30px;
}

.step {
  background: #ffffff;
  padding: 30px;
  border-radius: 16px;
  border: 1px solid #e5e7eb;
  text-align: center;
}

.step span {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  background: #0ea5e9;
  color: #ffffff;
  border-radius: 50%;
  font-weight: 700;
  margin-bottom: 14px;
}

/* =========================
   USE CASES
========================= */
.usecases {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}

.usecase {
  padding: 24px;
  border-radius: 14px;
  background: #f9fafb;
  border: 1px solid #e5e7eb;
  text-align: center;
  font-weight: 500;
}

/* =========================
   CTA
========================= */
.cta {
  padding: 120px 0;
  background: linear-gradient(135deg, #0ea5e9, #38bdf8);
  color: #ffffff;
}

.cta h2 {
  font-size: 44px;
  margin-bottom: 30px;
}

/* =========================
   FOOTER
========================= */
.footer {
  background: #0f172a;
  color: #cbd5f5;
  padding: 60px 0 30px;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: 30px;
}

.footer a {
  display: block;
  margin-bottom: 10px;
  color: #cbd5f5;
}

.footer-bottom {
  border-top: 1px solid rgba(255,255,255,.1);
  margin-top: 30px;
  padding-top: 20px;
  text-align: center;
  font-size: 14px;
  color: #94a3b8;
}

/* =========================
   MOBILE
========================= */
@media (max-width: 900px) {
  .hero-grid {
    grid-template-columns: 1fr;
    text-align: center;
  }

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

  .features,
  .steps,
  .usecases {
    grid-template-columns: 1fr 1fr;
  }
}

@media (max-width: 600px) {
  nav {
    display: none;
    position: absolute;
    top: 72px;
    right: 20px;
    background: #ffffff;
    border: 1px solid #e5e7eb;
    padding: 20px;
    border-radius: 16px;
    flex-direction: column;
  }

  nav.show {
    display: flex;
  }

  nav a {
    margin: 10px 0;
  }

  .nav-toggle {
    display: block;
  }

  .features,
  .steps,
  .usecases {
    grid-template-columns: 1fr;
  }

  .hero h1 {
    font-size: 42px;
  }
}
/* =========================
   AUTH (LOGIN / REGISTER)
========================= */
.auth {
  min-height: calc(100vh - 72px);
  display: flex;
  align-items: center;
  justify-content: center;
  background: #f9fafb;
  padding: 80px 20px;
}

.auth-card {
  width: 100%;
  max-width: 420px;
  background: #ffffff;
  border-radius: 20px;
  padding: 40px;
  border: 1px solid #e5e7eb;
  box-shadow: 0 20px 50px rgba(0,0,0,.08);
}

.auth-card h1 {
  font-size: 28px;
  margin-bottom: 10px;
}

.auth-sub {
  color: #6b7280;
  margin-bottom: 30px;
}

.field {
  margin-bottom: 20px;
}

.field label {
  display: block;
  font-size: 14px;
  margin-bottom: 6px;
  color: #374151;
}

.field input {
  width: 100%;
  padding: 12px 14px;
  border-radius: 10px;
  border: 1px solid #d1d5db;
  font-size: 15px;
}

.field input:focus {
  outline: none;
  border-color: #0ea5e9;
  box-shadow: 0 0 0 3px rgba(14,165,233,.2);
}

.btn-primary.full {
  width: 100%;
  margin-top: 10px;
}

.auth-links {
  margin-top: 20px;
  text-align: center;
  font-size: 14px;
}

.auth-links a {
  color: #0ea5e9;
}

.auth-links span {
  margin: 0 8px;
  color: #9ca3af;
}