:root {
  --bg: #0c0f0d;
  --surface: #141a17;
  --border: #243028;
  --text: #e8f0eb;
  --muted: #8aa396;
  --accent: #5cff9d;
  --accent-dim: #3ecf7a;
  --bubble-me: #1a2420;
  --bubble-them: #111613;
  --font: 'DM Sans', system-ui, sans-serif;
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  line-height: 1.55;
  min-height: 100vh;
}

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

a:hover {
  text-decoration: underline;
}

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1.25rem 2rem;
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  background: rgba(12, 15, 13, 0.9);
  backdrop-filter: blur(12px);
  z-index: 10;
}

.logo {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--text);
  text-decoration: none;
  letter-spacing: -0.03em;
}

.nav nav {
  display: flex;
  gap: 1.5rem;
  align-items: center;
}

.nav nav a:not(.btn) {
  color: var(--muted);
  font-size: 0.95rem;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.75rem 1.35rem;
  border-radius: 999px;
  font-weight: 600;
  font-size: 0.95rem;
  text-decoration: none;
  border: none;
  cursor: pointer;
  transition: transform 0.15s, background 0.15s;
}

.btn:hover {
  text-decoration: none;
  transform: translateY(-1px);
}

.btn-primary {
  background: var(--accent);
  color: #062012;
}

.btn-primary:hover {
  background: var(--accent-dim);
}

.btn-ghost {
  background: transparent;
  color: var(--text);
  border: 1px solid var(--border);
}

.btn-sm {
  padding: 0.5rem 1rem;
  font-size: 0.875rem;
}

.hero {
  max-width: 720px;
  margin: 0 auto;
  padding: 4rem 2rem 3rem;
  text-align: center;
}

.eyebrow {
  color: var(--muted);
  font-size: 0.875rem;
  text-transform: lowercase;
  letter-spacing: 0.04em;
  margin-bottom: 1rem;
}

.hero h1 {
  font-size: clamp(2.5rem, 6vw, 3.75rem);
  font-weight: 700;
  letter-spacing: -0.04em;
  line-height: 1.05;
  margin-bottom: 1.25rem;
}

.lead {
  color: var(--muted);
  font-size: 1.125rem;
  max-width: 540px;
  margin: 0 auto 2rem;
}

.hero-actions {
  display: flex;
  gap: 1rem;
  justify-content: center;
  flex-wrap: wrap;
  margin-bottom: 3rem;
}

.chat-demo {
  text-align: left;
  max-width: 420px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 0.65rem;
}

.bubble {
  padding: 0.75rem 1rem;
  border-radius: 1rem;
  font-size: 0.95rem;
  max-width: 90%;
}

.bubble.them {
  background: var(--bubble-them);
  border: 1px solid var(--border);
  align-self: flex-start;
  border-bottom-left-radius: 0.25rem;
}

.bubble.me {
  background: var(--bubble-me);
  border: 1px solid #2a4034;
  align-self: flex-end;
  border-bottom-right-radius: 0.25rem;
  color: var(--text);
}

.features,
.pricing {
  max-width: 960px;
  margin: 0 auto;
  padding: 4rem 2rem;
}

.features h2,
.pricing h2 {
  text-align: center;
  font-size: 1.75rem;
  margin-bottom: 2.5rem;
  letter-spacing: -0.02em;
}

.grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 1.25rem;
}

.grid article,
.plan {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 1rem;
  padding: 1.5rem;
}

.grid h3,
.plan h3 {
  font-size: 1.1rem;
  margin-bottom: 0.5rem;
}

.grid p,
.plan li {
  color: var(--muted);
  font-size: 0.95rem;
}

.plans {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 1.5rem;
  align-items: start;
}

.plan-pro {
  border-color: #2a5040;
  position: relative;
}

.badge {
  position: absolute;
  top: -0.6rem;
  right: 1rem;
  background: var(--accent);
  color: #062012;
  font-size: 0.75rem;
  font-weight: 700;
  padding: 0.2rem 0.6rem;
  border-radius: 999px;
  text-transform: uppercase;
}

.price {
  font-size: 2.5rem;
  font-weight: 700;
  margin: 0.75rem 0 1.25rem;
  letter-spacing: -0.03em;
}

.price span {
  font-size: 1rem;
  font-weight: 500;
  color: var(--muted);
}

.plan ul {
  list-style: none;
  margin-bottom: 1.5rem;
}

.plan li {
  padding: 0.35rem 0;
  padding-left: 1.25rem;
  position: relative;
}

.plan li::before {
  content: '→';
  position: absolute;
  left: 0;
  color: var(--accent);
}

.plan-btn {
  width: 100%;
}

.pro-form {
  display: flex;
  flex-direction: column;
  gap: 0.65rem;
}

.pro-form label {
  font-size: 0.85rem;
  color: var(--muted);
}

.pro-form input {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 0.5rem;
  padding: 0.75rem 1rem;
  color: var(--text);
  font: inherit;
}

.pro-form input:focus {
  outline: 2px solid var(--accent);
  outline-offset: 1px;
}

.hint {
  font-size: 0.8rem;
  color: var(--muted);
}

footer {
  text-align: center;
  padding: 2rem;
  color: var(--muted);
  font-size: 0.9rem;
  border-top: 1px solid var(--border);
}

@media (max-width: 600px) {
  .nav nav a:not(.btn) {
    display: none;
  }
}