:root {
    --bg: #f5f6f4;
    --card: #ffffff;
    --ink: #1c1f1d;
    --muted: #5f6661;
    --line: #d9ddd8;
    --accent: #1f6f5c;
    --accent-ink: #ffffff;
    --error: #a23b2a;
}
@media (prefers-color-scheme: dark) {
    :root {
        --bg: #141716;
        --card: #1c201e;
        --ink: #e9ece9;
        --muted: #a1a8a3;
        --line: #333936;
        --accent: #4fb399;
        --accent-ink: #0d1412;
        --error: #ef8a76;
    }
}
* { box-sizing: border-box; }
body {
    margin: 0;
    background: var(--bg);
    color: var(--ink);
    font: 16px/1.5 system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
}
main { max-width: 560px; margin: 0 auto; padding: 24px 16px 48px; }
header { display: flex; align-items: baseline; gap: 10px; margin-bottom: 28px; }
.logo { font-weight: 700; letter-spacing: .02em; }
.tag { color: var(--muted); font-size: 14px; }
h1 { font-size: 24px; line-height: 1.25; margin: 0 0 12px; }
.lead { color: var(--muted); margin: 0 0 20px; }
.message {
    background: var(--card);
    border-left: 3px solid var(--accent);
    padding: 12px 14px;
    margin: 0 0 16px;
    white-space: pre-line;
}
.error { color: var(--error); font-weight: 600; }
fieldset {
    background: var(--card);
    border: 1px solid var(--line);
    border-radius: 10px;
    padding: 16px;
    margin: 0 0 16px;
}
legend { font-weight: 650; padding: 0 6px; }
.hint { color: var(--muted); font-size: 14px; margin: 0 0 8px; }
label { display: block; font-size: 14px; font-weight: 550; margin-top: 12px; }
.opt { color: var(--muted); font-weight: 400; }
input, textarea {
    display: block;
    width: 100%;
    margin-top: 4px;
    padding: 10px 12px;
    border: 1px solid var(--line);
    border-radius: 8px;
    background: var(--bg);
    color: var(--ink);
    font: inherit;
}
textarea { font-family: ui-monospace, Menlo, Consolas, monospace; font-size: 14px; }
input:focus, textarea:focus { outline: 2px solid var(--accent); outline-offset: 1px; }
button {
    width: 100%;
    padding: 12px;
    border: 0;
    border-radius: 8px;
    background: var(--accent);
    color: var(--accent-ink);
    font: inherit;
    font-weight: 650;
    cursor: pointer;
}
.foot { color: var(--muted); font-size: 14px; margin-top: 20px; }