/* Shared palette and typography. Demo terminal colors use these tokens too. */
:root {
    --bg: #f7f8fa;
    --panel: #ffffff;
    --panel-2: #eef1f5;
    --border: #dce2e9;
    --text: #192b40;
    --muted: #5b6b7c;
    --green: #087e80;
    --cyan: #2364a2;
    --yellow: #956812;
    --red: #b34040;
    --glow: rgba(35, 100, 162, 0.04);
    --shadow: 0 16px 45px rgba(25, 43, 64, 0.07);
    --term-bg: #ffffff;
    --sans: 'Inter', system-ui, sans-serif;
    --mono: 'JetBrains Mono', ui-monospace, monospace;
    color-scheme: light;
}
@media (prefers-color-scheme: dark) {
    :root:not([data-theme="light"]) {
        --bg: #101820; --panel: #16212c; --panel-2: #1c2936; --border: #2e3e4d;
        --text: #e3eaf0; --muted: #a0b0bf; --green: #63c5bf; --cyan: #7db9e7;
        --yellow: #d9b972; --red: #ef8e8e; --term-bg: #111b25;
        --glow: rgba(99, 197, 191, 0.025); --shadow: 0 16px 45px rgba(0, 0, 0, 0.15);
        color-scheme: dark;
    }
}
:root[data-theme="dark"] {
    --bg: #101820; --panel: #16212c; --panel-2: #1c2936; --border: #2e3e4d;
    --text: #e3eaf0; --muted: #a0b0bf; --green: #63c5bf; --cyan: #7db9e7;
    --yellow: #d9b972; --red: #ef8e8e; --term-bg: #111b25;
    --glow: rgba(99, 197, 191, 0.025); --shadow: 0 16px 45px rgba(0, 0, 0, 0.15);
    color-scheme: dark;
}
*, *::before, *::after { box-sizing: border-box; }
body, h1, h2, h3, p, pre { margin: 0; }
body { font-family: var(--sans); background: var(--bg); color: var(--text); line-height: 1.65; -webkit-font-smoothing: antialiased; }
a { color: var(--cyan); }
button, input, select, textarea { font: inherit; }
button { cursor: pointer; }
code, pre { font-family: var(--mono); }
[hidden] { display: none !important; }
:focus-visible { outline: 2px solid var(--cyan); outline-offset: 4px; }
.nav, main, .footer { width: min(100% - 3rem, 860px); margin-inline: auto; }
.skip-link { position: fixed; top: -5rem; left: 1rem; z-index: 10; padding: 0.75rem 1rem; background: var(--panel); }
.skip-link:focus { top: 1rem; }
.nav { display: flex; align-items: center; justify-content: space-between; min-height: 80px; border-bottom: 1px solid var(--border); }
.logo { font-family: var(--mono); font-weight: 700; font-size: 1.2rem; color: var(--text); text-decoration: none; letter-spacing: -0.05em; }
.logo span { color: var(--green); }
.nav-right { display: flex; align-items: center; gap: 1.25rem; }
.nav-link { font-size: 0.8rem; color: var(--muted); text-decoration: none; }
.nav-link:hover, .footer a:hover { color: var(--green); }
.button { display: inline-flex; align-items: center; justify-content: center; border: 1px solid var(--border); border-radius: 5px; background: var(--panel); color: var(--text); text-decoration: none; font-weight: 500; }
.button-small { padding: 0.35rem 1rem; font-size: 0.8rem; }
.button:hover, .button[aria-current] { border-color: var(--green); color: var(--green); }
.theme-btn { display: grid; place-content: center; width: 30px; height: 30px; padding: 0; background: transparent; border: 1px solid var(--border); border-radius: 5px; color: var(--muted); }
.theme-btn:hover { color: var(--text); }
.hero { text-align: center; padding: 3.5rem 0 2.75rem; }
h1 { font-size: clamp(2.25rem, 5vw, 3.3rem); line-height: 1.12; letter-spacing: -0.045em; font-weight: 600; }
.accent { color: var(--green); }
.hero p { margin-top: 1.25rem; font-size: 0.96rem; color: var(--muted); }
.section { padding: 1.8rem 0; }
h2 { font-size: 1.3rem; font-weight: 600; letter-spacing: -0.025em; margin-bottom: 1rem; }
/* Protocol stacks of different depths align at their base layers. */
.protocol-landscape { display: grid; grid-template-columns: repeat(9, minmax(0, 1fr)); align-items: end; gap: 10px; margin: 0; padding: 1.25rem 0 0.75rem; }
.protocol-stack { display: flex; flex-direction: column; gap: 5px; list-style: none; margin: 0; padding: 0; }
.protocol-stack li { display: grid; place-items: center; min-height: 36px; padding: 0.4rem 0.15rem; border: 1px solid var(--border); border-radius: 4px; background: var(--panel); color: var(--text); font-family: var(--mono); font-size: 0.7rem; line-height: 1.3; }
.protocol-stack .stack-llm { color: var(--bg); background: var(--green); border-color: var(--green); font-weight: 600; margin-bottom: 3px; }
.protocol-stack .stack-application { color: var(--cyan); border-color: color-mix(in srgb, var(--cyan) 30%, var(--border)); background: color-mix(in srgb, var(--cyan) 7%, var(--panel)); }
.protocol-stack .stack-transport { color: var(--cyan); }
.protocol-stack .stack-network { color: var(--muted); }
.protocol-stack .stack-link { background: var(--panel-2); color: var(--muted); }
.examples { display: grid; grid-template-columns: 1fr 1fr; gap: 1rem; }
.examples article { padding: 1.1rem; background: var(--panel); border: 1px solid var(--border); border-radius: 6px; }
.examples p { font-size: 0.85rem; line-height: 1.8; color: var(--green); }
.section-sub { color: var(--muted); font-size: 0.8rem; margin: -0.4rem 0 1rem; }
.proto-table { border: 1px solid var(--border); border-radius: 6px; overflow: hidden; font-family: var(--mono); font-size: 0.73rem; }
.proto-row { display: grid; grid-template-columns: 155px 1fr; }
.proto-row + .proto-row { border-top: 1px solid var(--border); }
.proto-row:nth-child(odd) { background: var(--panel); }
.proto-cat { color: var(--cyan); font-size: 0.64rem; text-transform: uppercase; letter-spacing: 0.025em; padding: 0.65rem 0.8rem; border-right: 1px solid var(--border); }
.proto-list { display: flex; flex-wrap: wrap; align-content: flex-start; gap: 0.2rem 0.8rem; color: var(--muted); padding: 0.65rem 0.8rem; }
.proto-list a { color: inherit; text-decoration: none; overflow-wrap: anywhere; }
.proto-list a:hover { color: var(--green); text-decoration: underline; text-underline-offset: 3px; }
.sub-h { font-size: 0.9rem; font-weight: 600; margin-top: 1.5rem; margin-bottom: 0.5rem; }
.section > h2 + .sub-h { margin-top: 0; }
.code-block { position: relative; background: var(--panel); border: 1px solid var(--border); border-radius: 6px; margin-block: 0.75rem; overflow: hidden; }
.code-block pre { padding: 1.1rem; overflow-x: auto; font-size: 0.76rem; line-height: 1.8; }
.c { color: var(--muted); }
.str { color: var(--green); }
.copy-btn { position: absolute; top: 0.5rem; right: 0.5rem; background: var(--panel-2); color: var(--muted); border: 1px solid var(--border); padding: 0.2rem 0.55rem; border-radius: 4px; font-family: var(--mono); font-size: 0.65rem; }
.copy-btn:hover { color: var(--text); border-color: var(--muted); }
.copy-btn.copied { color: var(--bg); background: var(--green); border-color: var(--green); }
.caption { color: var(--muted); font-size: 0.78rem; margin-top: 0.5rem; overflow-wrap: anywhere; }
.caption code { font-size: 0.73rem; }
.footer { display: flex; align-items: center; justify-content: center; gap: 0.9rem; padding-block: 1.5rem 2rem; margin-top: 1.5rem; border-top: 1px solid var(--border); color: var(--muted); font-size: 0.75rem; }
.footer a { color: var(--muted); text-decoration: none; }
.sep { color: var(--border); }
main.demo-main { width: 100%; max-width: none; }
.demo-intro { width: min(100% - 3rem, 1288px); margin: 2rem auto 1.5rem; }
.demo-intro h1 { font-size: 1.5rem; }
.demo-intro p { margin-top: 0.5rem; font-size: 0.85rem; color: var(--muted); }
@media (max-width: 760px) {
    .protocol-landscape { grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 1.5rem 0.75rem; padding-top: 0.25rem; }
    .protocol-stack li { min-height: 32px; font-size: 0.73rem; }
}
@media (max-width: 600px) {
    .nav, main, .footer { width: calc(100% - 2.5rem); }
    .nav { min-height: 70px; }
    .nav-right { gap: 1rem; }
    .hero { padding: 2.5rem 0 1.5rem; }
    .hero p { font-size: 0.88rem; }
    .wide-only { display: none; }
    .section { padding-block: 1.5rem; }
    .examples { grid-template-columns: 1fr; gap: 0.75rem; }
    .proto-row { grid-template-columns: 105px 1fr; }
    .proto-cat, .proto-list { padding: 0.6rem; }
    .code-block pre { padding: 2.5rem 1rem 1rem; font-size: 0.7rem; }
    .demo-intro { width: calc(100% - 2rem); }
}
@media (prefers-reduced-motion: reduce) {
    *, *::before, *::after { animation: none !important; transition: none !important; }
}