:root {
    color-scheme: light dark;
    --bg: #ffffff;
    --fg: #1a1a1a;
    --muted: #666;
    --line: #e2e2e2;
    --card: #fafafa;
    --accent: #2d6cdf;
}
@media (prefers-color-scheme: dark) {
    :root {
        --bg: #14161a;
        --fg: #e8e8e8;
        --muted: #9aa0a6;
        --line: #2a2e35;
        --card: #1b1e24;
        --accent: #6ea8ff;
    }
}

* {
    box-sizing: border-box;
}
body {
    margin: 0;
    padding: 0 20px 60px;
    font-family: system-ui, -apple-system, "Segoe UI", sans-serif;
    color: var(--fg);
    background: var(--bg);
    line-height: 1.5;
}
header,
main,
footer {
    max-width: 980px;
    margin: 0 auto;
}
header {
    padding: 32px 0 8px;
}
h1 {
    margin: 0 0 4px;
    font-size: 1.9rem;
}
.tagline {
    margin: 0 0 8px;
    font-size: 1.1rem;
    color: var(--fg);
}
.links a {
    color: var(--accent);
    text-decoration: none;
    font-weight: 600;
}
.note {
    color: var(--muted);
    font-size: 0.92rem;
    max-width: 70ch;
}
code {
    background: var(--card);
    border: 1px solid var(--line);
    border-radius: 4px;
    padding: 0.05em 0.35em;
    font-size: 0.88em;
}

.scenario {
    border-top: 1px solid var(--line);
    padding: 22px 0;
}
.scenario h2 {
    margin: 0 0 2px;
    font-size: 1.1rem;
}
.scenario .desc {
    margin: 0 0 14px;
    color: var(--muted);
    font-size: 0.9rem;
}
.pair {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 18px;
}
figure {
    margin: 0;
}
figcaption {
    margin-top: 8px;
    font-size: 0.8rem;
    color: var(--muted);
}
figcaption .label {
    display: inline-block;
    font-weight: 700;
    color: var(--fg);
    margin-bottom: 2px;
}
figcaption .saving {
    color: #1a8a3a;
    font-weight: 700;
}
@media (prefers-color-scheme: dark) {
    figcaption .saving {
        color: #5fd07f;
    }
}
figcaption .measure {
    font-variant-numeric: tabular-nums;
}
.box {
    border: 1px solid var(--line);
    border-radius: 6px;
    background-color: var(--card);
}
.stat {
    display: inline-block;
    min-width: 3.5em;
}

@media (max-width: 620px) {
    .pair {
        grid-template-columns: 1fr;
    }
}