:root {
    color-scheme: light dark;
    --ink: #16181d;
    --muted: #5b6270;
    --rule: #e3e6ec;
    --ground: #ffffff;
    --accent: #3b5fd6;
}
@media (prefers-color-scheme: dark) {
    :root {
        --ink: #eceef3;
        --muted: #9aa2b1;
        --rule: #262b35;
        --ground: #0d1014;
        --accent: #7d9bff;
    }
}
* { box-sizing: border-box; }
body {
    margin: 0;
    background: var(--ground);
    color: var(--ink);
    font: 17px/1.65 -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
    -webkit-font-smoothing: antialiased;
}
.wrap { max-width: 44rem; margin: 0 auto; padding: 4rem 1.5rem 6rem; }
header { border-bottom: 1px solid var(--rule); padding-bottom: 1.5rem; margin-bottom: 2.5rem; }
h1 { font-size: 2rem; letter-spacing: -0.02em; margin: 0 0 .3rem; }
h2 { font-size: 1.15rem; letter-spacing: -0.01em; margin: 2.5rem 0 .6rem; }
.sub { color: var(--muted); margin: 0; }
p, li { color: var(--ink); }
.muted { color: var(--muted); font-size: .93rem; }
a { color: var(--accent); }
nav a { margin-right: 1.2rem; text-decoration: none; }
nav { margin-top: 1rem; font-size: .95rem; }
ul { padding-left: 1.2rem; }
li { margin: .35rem 0; }
footer { margin-top: 4rem; padding-top: 1.5rem; border-top: 1px solid var(--rule); }

/* Landing page */
.hero { text-align: center; border: none; padding-bottom: 0; margin-bottom: 3rem; }
.hero .mark { color: var(--accent); margin-bottom: 1rem; }
.hero h1 { font-size: 2.4rem; line-height: 1.15; margin: 0 0 1rem; }
.lede { font-size: 1.12rem; color: var(--muted); max-width: 34rem; margin: 0 auto 1.8rem; }
.cta { display: flex; gap: .7rem; justify-content: center; flex-wrap: wrap; margin: 0; }
.button {
    display: inline-block; padding: .7rem 1.4rem; border-radius: 999px;
    border: 1px solid var(--rule); text-decoration: none; color: var(--ink);
    font-weight: 500; font-size: .97rem;
}
.button.primary { background: var(--accent); border-color: var(--accent); color: #fff; }
.fine { color: var(--muted); font-size: .87rem; margin-top: 1rem; }
section { margin: 3.2rem 0; }
section h2 { margin-top: 0; }
.proof pre {
    background: rgba(127,127,127,.12); padding: .9rem 1rem; border-radius: 8px;
    overflow-x: auto; font-size: .87rem;
}
.proof code { font-family: ui-monospace, SFMono-Regular, Menlo, monospace; }
.features { list-style: none; padding: 0; }
.features li { padding: .55rem 0; border-bottom: 1px solid var(--rule); }
.features li:last-child { border-bottom: none; }
.limits { border-left: 3px solid var(--rule); padding-left: 1.2rem; }
footer nav { margin-bottom: .8rem; }