:root {
    --bg: #f4f6f5;
    --panel: #ffffff;
    --ink: #16211e;
    --muted: #5d6c67;
    --line: #d5ddda;
    --accent: #0b6f5f;
    --accent-ink: #ffffff;
    --soft: #e0f0ec;
    --ok: #1d7a3a;
    --ko: #b42318;
    --code-bg: #12201c;
    --code-ink: #d8eee8;
}

@media (prefers-color-scheme: dark) {
    :root {
        --bg: #0e1514;
        --panel: #152120;
        --ink: #e3ece9;
        --muted: #9bb0aa;
        --line: #27403b;
        --accent: #45cdb5;
        --accent-ink: #06201b;
        --soft: #173430;
        --ok: #5fd38a;
        --ko: #ff8a7a;
        --code-bg: #0a100f;
        --code-ink: #cfe9e2;
        color-scheme: dark;
    }
}

* { box-sizing: border-box; }

body {
    margin: 0;
    background: var(--bg);
    color: var(--ink);
    font-family: system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
    font-size: 17px;
    line-height: 1.6;
}

.wrap { max-width: 800px; margin: 0 auto; padding: 0 16px; }
a { color: var(--accent); }
a:focus-visible, button:focus-visible, input:focus-visible, textarea:focus-visible, select:focus-visible {
    outline: 3px solid var(--accent);
    outline-offset: 2px;
}

.top { border-bottom: 1px solid var(--line); background: var(--panel); }
.bar { display: flex; align-items: center; justify-content: space-between; gap: 12px; flex-wrap: wrap; padding-block: 12px; }
.brand { font-weight: 700; font-size: 20px; color: var(--ink); text-decoration: none; }
nav { display: flex; gap: 14px; align-items: center; flex-wrap: wrap; }
nav a { text-decoration: none; }

h1 { font-size: clamp(28px, 6vw, 40px); line-height: 1.2; margin: 24px 0 8px; text-wrap: balance; }
h2 { font-size: 24px; margin: 36px 0 12px; }
h3 { font-size: 19px; margin: 20px 0 6px; }
.lead { font-size: 19px; color: var(--muted); max-width: 62ch; }
.eyebrow { font-size: 13px; letter-spacing: .08em; text-transform: uppercase; color: var(--muted); font-weight: 600; margin: 20px 0 0; }
.muted { color: var(--muted); }
.crumb { margin: 18px 0 0; font-size: 15px; }

.hero { padding-block: 12px 8px; }

.grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(min(100%, 280px), 1fr)); gap: 14px; }
.card { display: block; background: var(--panel); border: 1px solid var(--line); border-radius: 6px; padding: 14px 16px; color: inherit; text-decoration: none; min-width: 0; }
.card:hover { border-color: var(--accent); }
.card h3 { margin: 4px 0; }
.card p { margin: 0 0 8px; color: var(--muted); font-size: 15px; }

.module { background: var(--panel); border: 1px solid var(--line); border-radius: 6px; padding: 4px 16px 14px; margin: 14px 0; }
.lessons { list-style: none; padding: 0; margin: 0; }
.lessons li { padding: 8px 0; border-bottom: 1px solid var(--line); display: flex; gap: 10px; flex-wrap: wrap; align-items: baseline; }
.lessons li:last-child { border-bottom: 0; }

.tag { display: inline-block; font-size: 13px; font-weight: 600; padding: 1px 9px; border: 1px solid var(--muted); color: var(--muted); border-radius: 99px; }
.tag.ok { color: var(--ok); border-color: var(--ok); }
.tag.ko { color: var(--ko); border-color: var(--ko); }

.btn { display: inline-block; font: inherit; font-weight: 600; background: var(--accent); color: var(--accent-ink); border: 1px solid var(--accent); border-radius: 6px; padding: 9px 16px; cursor: pointer; text-decoration: none; }
.btn.ghost { background: transparent; color: var(--accent); }
.btn.small { padding: 4px 12px; font-size: 15px; }
.btn.danger { background: transparent; color: var(--ko); border-color: var(--ko); }

.flash { border-left: 4px solid var(--accent); background: var(--soft); padding: 10px 14px; margin: 16px 0; border-radius: 0 6px 6px 0; }
.flash.error { border-color: var(--ko); }

.bar-track { height: 10px; background: var(--line); border-radius: 5px; overflow: hidden; }
.bar-track span { display: block; height: 100%; background: var(--accent); }

.prose { max-width: 66ch; }
.prose pre { background: var(--code-bg); color: var(--code-ink); padding: 14px; border-radius: 6px; overflow-x: auto; font-size: 14px; line-height: 1.5; }
.prose code { font-family: ui-monospace, Menlo, Consolas, monospace; font-size: .9em; }
.prose :not(pre) > code { background: var(--soft); padding: 1px 5px; border-radius: 4px; }

.actions { margin: 28px 0; }
.pager { display: flex; justify-content: space-between; gap: 12px; flex-wrap: wrap; margin-top: 32px; }

.stack { display: grid; gap: 14px; max-width: 480px; }
.stack label { display: block; font-weight: 600; margin-bottom: 4px; }
input[type="text"], input[type="email"], input[type="password"], input[type="number"], textarea, select {
    width: 100%; font: inherit; padding: 9px 11px; border: 1px solid var(--line); border-radius: 6px; background: var(--panel); color: var(--ink);
}
form ul { color: var(--ko); padding-left: 18px; margin: 4px 0; }

.q { border: 1px solid var(--line); background: var(--panel); border-radius: 6px; padding: 12px 16px; margin: 0 0 12px; min-width: 0; }
.q legend { font-weight: 600; padding: 0 6px; }
.q label { display: flex; gap: 10px; align-items: flex-start; padding: 5px 0; cursor: pointer; }
.q input { margin-top: 7px; accent-color: var(--accent); }
.q.ok { border-color: var(--ok); }
.q.ko { border-color: var(--ko); }
.score { font-size: 40px; font-weight: 700; margin: 8px 0; }

.foot { color: var(--muted); font-size: 14px; padding-block: 40px 24px; }