:root {
    --bg: #eef1f5; --surface: #ffffff; --text: #17202b; --muted: #566171; --border: #d6dce4;
    --accent: #1f4e8c; --accent-text: #ffffff; --ok: #1d6b3a; --ok-bg: #e4f3e9; --err: #a3271f; --err-bg: #fbe8e6;
    --notice-bg: #fff8e1; --notice-text: #5c4400;
}
@media (prefers-color-scheme: dark) {
    :root {
        --bg: #10141a; --surface: #19202a; --text: #e7eaef; --muted: #9aa5b4; --border: #2c3542;
        --accent: #73a6ec; --accent-text: #0c1016; --ok: #82d6a0; --ok-bg: #15301f; --err: #ff9d94; --err-bg: #3b1714;
        --notice-bg: #33290c; --notice-text: #f4d58a;
    }
}
* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body { margin: 0; font: 16px/1.55 "Segoe UI", system-ui, -apple-system, sans-serif; background: var(--bg); color: var(--text); }
a { color: var(--accent); }
header.top { padding: 14px 16px; background: var(--surface); border-bottom: 1px solid var(--border); }
.brand { max-width: 640px; margin: 0 auto; font-weight: 600; display: flex; align-items: center; gap: 10px; }
.mark { display: inline-grid; place-items: center; width: 28px; height: 28px; border-radius: 6px; background: var(--accent); color: var(--accent-text); font-weight: 700; }
main { max-width: 640px; margin: 24px auto; padding: 0 16px; }
footer { max-width: 640px; margin: 0 auto 32px; padding: 0 16px; color: var(--muted); font-size: 13px; }
.card { background: var(--surface); border: 1px solid var(--border); border-radius: 10px; padding: 22px 24px; margin-bottom: 16px; }
h1 { font-size: 24px; line-height: 1.25; margin: 0 0 12px; }
h2 { font-size: 18px; margin: 22px 0 8px; }
h3 { font-size: 16px; margin: 18px 0 6px; }
.steps { display: flex; gap: 6px; list-style: none; padding: 0; margin: 0 0 14px; flex-wrap: wrap; font-size: 13px; color: var(--muted); }
.steps li { padding: 2px 10px; border-radius: 12px; border: 1px solid var(--border); }
.steps li.now { border-color: var(--accent); color: var(--accent); font-weight: 600; }
.steps li.done { background: var(--ok-bg); color: var(--ok); border-color: transparent; }
label { display: block; font-weight: 600; margin: 14px 0 6px; }
.hint { color: var(--muted); font-size: 14px; font-weight: 400; }
input[type=text], input[type=email], input[type=password] {
    width: 100%; padding: 10px 12px; font: inherit; border: 1px solid var(--border); border-radius: 8px; background: var(--bg); color: var(--text);
}
input.code { font-size: 22px; letter-spacing: 6px; max-width: 220px; font-family: Consolas, "Cascadia Mono", monospace; }
button, .button {
    display: inline-block; margin-top: 18px; padding: 11px 20px; font: inherit; font-weight: 600; border-radius: 8px; border: 1px solid var(--accent);
    background: var(--accent); color: var(--accent-text); cursor: pointer; text-decoration: none;
}
button.secondary { background: transparent; color: var(--accent); }
.row { display: flex; gap: 10px; flex-wrap: wrap; align-items: center; }
.note { padding: 12px 14px; border-radius: 8px; margin-bottom: 16px; }
.note.ok { background: var(--ok-bg); color: var(--ok); }
.note.err { background: var(--err-bg); color: var(--err); }
.notice { background: var(--notice-bg); color: var(--notice-text); border-radius: 8px; padding: 12px 14px; font-size: 14px; }
.check { display: flex; gap: 10px; align-items: flex-start; font-weight: 400; }
.check input { margin-top: 4px; }
.qr { background: #fff; padding: 10px; border-radius: 8px; width: 240px; max-width: 100%; display: block; }
.mono { font-family: Consolas, "Cascadia Mono", monospace; overflow-wrap: anywhere; }
.copyable { display: flex; gap: 8px; align-items: center; flex-wrap: wrap; }
.copyable .mono { background: var(--bg); border: 1px solid var(--border); border-radius: 6px; padding: 6px 10px; }
.copyable button { margin-top: 0; padding: 6px 12px; }
ol.quiz { padding-left: 20px; }
ol.quiz fieldset { border: none; padding: 0; margin: 0 0 18px; }
ol.quiz legend { font-weight: 600; margin-bottom: 6px; }
.choice { display: flex; gap: 10px; font-weight: 400; margin: 6px 0; align-items: flex-start; }
.choice input { margin-top: 5px; }
ul.projects { padding-left: 20px; }
.briefing h2 { font-size: 20px; }
:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }