:root {
  --teal: #00A292;
  --yellow: #FFFF9A;
  --ink: #12181c;
  --paper: #ffffff;
  --muted: #5a6470;
  --border: #e2e6e9;
  --code-bg: #f4f6f7;
  --radius: 10px;
  color-scheme: light dark;
}

@media (prefers-color-scheme: dark) {
  :root {
    --ink: #eef1f3;
    --paper: #14181b;
    --muted: #9aa5ad;
    --border: #2a3136;
    --code-bg: #1c2124;
  }
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  color: var(--ink);
  background: var(--paper);
  line-height: 1.55;
}

a { color: var(--teal); }

.hero {
  text-align: center;
  padding: 4rem 1.5rem 3rem;
  background: linear-gradient(180deg, rgba(0,162,146,0.08), transparent);
}

.logo {
  border-radius: 50%;
  margin-bottom: 1rem;
}

.hero h1 {
  margin: 0;
  font-size: 3rem;
  letter-spacing: -0.02em;
}

.tagline {
  max-width: 40rem;
  margin: 0.75rem auto 2rem;
  color: var(--muted);
  font-size: 1.15rem;
}

.cta-row {
  display: flex;
  gap: 1rem;
  justify-content: center;
  flex-wrap: wrap;
}

.btn {
  display: inline-block;
  padding: 0.75rem 1.5rem;
  border-radius: var(--radius);
  text-decoration: none;
  font-weight: 600;
  border: 2px solid transparent;
}

.btn-primary {
  background: var(--teal);
  color: #fff;
}

.btn-secondary {
  border-color: var(--border);
  color: var(--ink);
}

.version-banner {
  margin-top: 1.5rem;
  font-size: 0.9rem;
  color: var(--muted);
}

main {
  max-width: 56rem;
  margin: 0 auto;
  padding: 0 1.5rem 4rem;
}

.panel {
  padding: 2.5rem 0;
  border-top: 1px solid var(--border);
}

.panel:first-of-type {
  border-top: none;
}

.panel h2 {
  margin-top: 0;
}

.callout {
  border: 1px solid var(--teal);
  background: rgba(0, 162, 146, 0.08);
  border-radius: var(--radius);
  padding: 1rem 1.25rem;
  margin: 1.25rem 0;
}

.columns {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2rem;
  margin-top: 1.5rem;
}

@media (max-width: 40rem) {
  .columns { grid-template-columns: 1fr; }
}

.columns h3 {
  margin-top: 0;
  font-size: 1rem;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: var(--muted);
}

code {
  background: var(--code-bg);
  padding: 0.15em 0.4em;
  border-radius: 4px;
  font-size: 0.9em;
}

pre {
  background: var(--code-bg);
  padding: 1.25rem;
  border-radius: var(--radius);
  overflow-x: auto;
}

pre code {
  background: none;
  padding: 0;
}

table.downloads {
  width: 100%;
  border-collapse: collapse;
  margin: 1.5rem 0;
}

table.downloads caption {
  text-align: left;
  font-weight: 600;
  margin-bottom: 0.5rem;
}

table.downloads th, table.downloads td {
  text-align: left;
  padding: 0.6rem 0.5rem;
  border-bottom: 1px solid var(--border);
}

table.downloads a {
  font-weight: 600;
  text-decoration: none;
}

table.downloads a:hover {
  text-decoration: underline;
}

.tabs {
  margin-top: 1.5rem;
}

.tab-input {
  position: absolute;
  opacity: 0;
  pointer-events: none;
}

.tab-labels {
  display: flex;
  gap: 0.5rem;
  border-bottom: 1px solid var(--border);
}

.tab-labels label {
  cursor: pointer;
  padding: 0.6rem 1rem;
  font-weight: 600;
  color: var(--muted);
  border-bottom: 2px solid transparent;
  margin-bottom: -1px;
  user-select: none;
}

.tab-labels label:hover {
  color: var(--ink);
}

.tab-panel {
  display: none;
}

#tab-server:checked ~ .tab-labels label[for="tab-server"],
#tab-client:checked ~ .tab-labels label[for="tab-client"] {
  color: var(--teal);
  border-bottom-color: var(--teal);
}

#tab-server:checked ~ .tab-panels #panel-server,
#tab-client:checked ~ .tab-panels #panel-client {
  display: block;
}

table.downloads {
  margin-top: 1rem;
}

.use-cases {
  padding-left: 1.2rem;
}

.muted {
  color: var(--muted);
}

footer {
  text-align: center;
  padding: 2rem 1.5rem 3rem;
  color: var(--muted);
  font-size: 0.9rem;
}