:root {
    color-scheme: light dark;
    --bg: #f4f5f7;
    --card: #ffffff;
    --text: #1d2330;
    --muted: #5d6675;
    --line: #d9dde3;
    --accent: #1f5fbf;
    --accent-text: #ffffff;
    --error: #b42318;
}

@media (prefers-color-scheme: dark) {
    :root {
        --bg: #12151b;
        --card: #1b2029;
        --text: #e6e9ef;
        --muted: #9aa3b2;
        --line: #2e3542;
        --accent: #5b8def;
        --accent-text: #0d1117;
        --error: #f97066;
    }
}

* { box-sizing: border-box; }

body {
    margin: 0;
    min-height: 100vh;
    display: grid;
    place-items: center;
    padding: 16px;
    background: var(--bg);
    color: var(--text);
    font: 16px/1.5 system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
}

.card {
    width: 100%;
    max-width: 420px;
    background: var(--card);
    border: 1px solid var(--line);
    border-radius: 12px;
    padding: 28px 24px;
}

h1 { margin: 0 0 4px; font-size: 1.4rem; }

.muted { color: var(--muted); margin: 0 0 20px; }

label { display: block; font-weight: 600; margin: 0 0 6px; }

input[type="text"] {
    width: 100%;
    padding: 12px;
    margin: 0 0 16px;
    font: inherit;
    letter-spacing: 0.04em;
    color: var(--text);
    background: transparent;
    border: 1px solid var(--line);
    border-radius: 8px;
}

fieldset { border: 0; padding: 0; margin: 0 0 16px; }
legend { font-weight: 600; margin-bottom: 6px; }

.choice {
    display: flex;
    gap: 10px;
    align-items: flex-start;
    font-weight: 400;
    padding: 10px;
    border: 1px solid var(--line);
    border-radius: 8px;
    margin-bottom: 8px;
    cursor: pointer;
}
.choice input { margin-top: 4px; }
.choice span { font-size: 0.92rem; color: var(--muted); }
.choice strong { color: var(--text); }

button.primary {
    width: 100%;
    padding: 14px;
    font: inherit;
    font-weight: 600;
    color: var(--accent-text);
    background: var(--accent);
    border: 0;
    border-radius: 8px;
    cursor: pointer;
}
button.primary:disabled { opacity: 0.6; cursor: wait; }

.status { min-height: 1.5em; margin: 14px 0 0; }
.status.error { color: var(--error); }

.foot { margin: 20px 0 0; font-size: 0.92rem; color: var(--muted); }
a { color: var(--accent); }
code { font-size: 0.9em; }