:root {
  --bg: #fafaf9;
  --fg: #1a1a1a;
  --muted: #6b6b6b;
  --border: #e5e5e3;
  --accent: #0f5e9c;
  --accent-fg: #ffffff;
  --card-bg: #ffffff;
  --feature: #f0f7fc;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #14171a;
    --fg: #e8e8e8;
    --muted: #999;
    --border: #2a2e33;
    --accent: #4a9eff;
    --accent-fg: #0a0a0a;
    --card-bg: #1c2026;
    --feature: #1a2832;
  }
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  background: var(--bg);
  color: var(--fg);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  font-size: 16px;
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
}

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

header {
  border-bottom: 1px solid var(--border);
  padding: 1rem 0;
}

header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

header .brand {
  font-weight: 700;
  font-size: 1.1rem;
  color: var(--fg);
}

header .brand small {
  color: var(--muted);
  font-weight: 400;
  margin-left: 0.5rem;
}

header nav a {
  color: var(--fg);
  margin-left: 1.5rem;
  font-size: 0.95rem;
}

.container {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 1.25rem;
}

h1 { font-size: 2rem; margin: 2rem 0 0.5rem; letter-spacing: -0.01em; }
h2 { font-size: 1.4rem; margin: 2rem 0 0.5rem; }
p.lede { color: var(--muted); font-size: 1.1rem; max-width: 38rem; }

.tiers {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 1rem;
  margin: 2rem 0;
}

.tier {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 1.5rem;
  display: flex;
  flex-direction: column;
}

.tier.featured {
  border-color: var(--accent);
  background: var(--feature);
}

.tier h3 {
  margin: 0 0 0.5rem;
  font-size: 1.1rem;
  letter-spacing: 0.02em;
  text-transform: uppercase;
  color: var(--muted);
}

.tier .price {
  font-size: 1.8rem;
  font-weight: 700;
  margin: 0.25rem 0;
}

.tier .price small {
  font-size: 0.9rem;
  font-weight: 400;
  color: var(--muted);
}

.tier ul {
  list-style: none;
  padding: 0;
  margin: 1rem 0;
  flex-grow: 1;
}

.tier ul li {
  padding: 0.35rem 0;
  font-size: 0.95rem;
  border-bottom: 1px dotted var(--border);
}

.tier ul li:last-child { border-bottom: none; }

.tier .cta {
  display: block;
  text-align: center;
  background: var(--accent);
  color: var(--accent-fg);
  padding: 0.7rem 1rem;
  border-radius: 6px;
  font-weight: 600;
  margin-top: 1rem;
  border: none;
  cursor: pointer;
  font-size: 1rem;
  font-family: inherit;
  width: 100%;
}

.tier .cta:hover { opacity: 0.92; text-decoration: none; }
.tier .cta[disabled] { opacity: 0.5; cursor: not-allowed; }

.tier.free .cta {
  background: transparent;
  color: var(--accent);
  border: 1px solid var(--accent);
}

form.signup {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 2rem;
  max-width: 24rem;
  margin: 2rem 0;
}

form.signup label {
  display: block;
  margin-bottom: 0.25rem;
  font-size: 0.9rem;
  color: var(--muted);
}

form.signup input[type=email],
form.signup input[type=password] {
  width: 100%;
  padding: 0.6rem 0.75rem;
  font-size: 1rem;
  border: 1px solid var(--border);
  border-radius: 4px;
  background: var(--bg);
  color: var(--fg);
  margin-bottom: 1rem;
  font-family: inherit;
}

form.signup .checkbox {
  display: flex;
  align-items: flex-start;
  gap: 0.5rem;
  margin: 1rem 0;
  font-size: 0.9rem;
}

form.signup .checkbox input { margin-top: 0.2rem; }

form.signup .cta {
  display: block;
  background: var(--accent);
  color: var(--accent-fg);
  padding: 0.7rem 1rem;
  border-radius: 6px;
  border: none;
  font-weight: 600;
  font-size: 1rem;
  width: 100%;
  cursor: pointer;
  font-family: inherit;
}

form.signup .cta[disabled] { opacity: 0.5; cursor: not-allowed; }

.message {
  margin: 1rem 0;
  padding: 0.75rem 1rem;
  border-radius: 4px;
  font-size: 0.95rem;
}

.message.success {
  background: rgba(16, 122, 60, 0.1);
  border: 1px solid rgba(16, 122, 60, 0.3);
  color: #107a3c;
}

.message.error {
  background: rgba(180, 35, 24, 0.1);
  border: 1px solid rgba(180, 35, 24, 0.3);
  color: #b42318;
}

.api-key {
  background: var(--bg);
  border: 1px solid var(--border);
  padding: 0.75rem;
  font-family: ui-monospace, "SF Mono", Menlo, monospace;
  font-size: 0.9rem;
  border-radius: 4px;
  word-break: break-all;
}

footer {
  border-top: 1px solid var(--border);
  margin-top: 4rem;
  padding: 2rem 0;
  color: var(--muted);
  font-size: 0.85rem;
}

footer .container {
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 1rem;
}

footer a { color: var(--muted); margin-right: 1rem; }