:root {
  --bg: #f6f7f9;
  --card: #ffffff;
  --fg: #14171a;
  --muted: #5b6570;
  --line: #e2e6ea;
  --accent: #1f6feb;
  --accent-fg: #ffffff;
  --ok: #1a7f4b;
  --bad: #b3261e;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0d1117;
    --card: #161b22;
    --fg: #e6edf3;
    --muted: #9198a1;
    --line: #2b323b;
    --accent: #4493f8;
    --accent-fg: #06121f;
    --ok: #3fb950;
    --bad: #f85149;
  }
}

* { box-sizing: border-box; }

body {
  margin: 0;
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 24px;
  background: var(--bg);
  color: var(--fg);
  font: 15px/1.55 -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto,
        Helvetica, Arial, sans-serif;
}

.card {
  width: 100%;
  max-width: 400px;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 32px;
}

.hd { text-align: center; margin-bottom: 24px; }

.mark {
  width: 44px;
  height: 44px;
  margin: 0 auto 12px;
  border-radius: 10px;
  background: var(--accent);
  color: var(--accent-fg);
  font-weight: 700;
  font-size: 15px;
  letter-spacing: .5px;
  display: flex;
  align-items: center;
  justify-content: center;
}

h1 { margin: 0; font-size: 17px; font-weight: 600; }
.sub { margin: 4px 0 0; color: var(--muted); font-size: 13px; }
.lede { margin: 0 0 16px; }
.signed { margin: 0 0 16px; color: var(--muted); font-size: 13px; text-align: center; }

label {
  display: block;
  margin-bottom: 6px;
  font-size: 13px;
  font-weight: 500;
  color: var(--muted);
}

input {
  width: 100%;
  padding: 10px 12px;
  font: inherit;
  color: var(--fg);
  background: var(--bg);
  border: 1px solid var(--line);
  border-radius: 8px;
}
input:focus {
  outline: 2px solid var(--accent);
  outline-offset: 1px;
  border-color: transparent;
}

button {
  width: 100%;
  margin-top: 14px;
  padding: 11px 14px;
  font: inherit;
  font-weight: 600;
  color: var(--accent-fg);
  background: var(--accent);
  border: 0;
  border-radius: 8px;
  cursor: pointer;
}
button:hover:not(:disabled) { filter: brightness(1.08); }
button:disabled { opacity: .6; cursor: default; }

.note {
  margin: 16px 0 0;
  font-size: 12.5px;
  line-height: 1.5;
  color: var(--muted);
}

.status { text-align: center; color: var(--muted); font-size: 13px; }

.ok, .bad {
  width: 40px;
  height: 40px;
  margin: 0 auto 14px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 20px;
  font-weight: 700;
  color: #fff;
}
.ok { background: var(--ok); }
.bad { background: var(--bad); }

#sent, #error { text-align: center; }