:root {
    --bg: #f6fbff;
    --card: #ffffff;
    --ink: #102a3b;
    --ink-soft: #3f5d70;
    --brand: #0f766e;
    --line: #d6e5ef;
    --max: 920px;
}

* { box-sizing: border-box; }

body {
    margin: 0;
    background: var(--bg);
    color: var(--ink);
    font-family: ui-sans-serif, system-ui, -apple-system, 'Segoe UI', Roboto, Arial, sans-serif;
    line-height: 1.65;
}

main {
    width: min(var(--max), calc(100% - 2rem));
    margin: 2rem auto;
    background: var(--card);
    border: 1px solid var(--line);
    border-radius: 16px;
    padding: 1.4rem 1.2rem 2rem;
}

h1, h2 {
    font-family: ui-serif, Georgia, Cambria, 'Times New Roman', serif;
}

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

nav {
    width: min(var(--max), calc(100% - 2rem));
    margin: 1.2rem auto 0;
}

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

.grid {
    display: grid;
    gap: .9rem;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
}

.box {
    border: 1px solid var(--line);
    border-radius: 12px;
    padding: .8rem;
    background: #f8fcff;
}