:root {
  --bg: #f6f7f9;
  --card: #ffffff;
  --text: #1c2024;
  --muted: #5b6470;
  --line: #dde1e6;
  --accent: #2f6fed;
  --danger: #c62828;
  --kakao: #fee500;
  color-scheme: light dark;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #121417;
    --card: #1c1f24;
    --text: #e8eaed;
    --muted: #a3abb5;
    --line: #2f343b;
    --accent: #7aa5ff;
    --danger: #ef6b6b;
  }
}

* { box-sizing: border-box; }
[hidden] { display: none !important; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 16px/1.55 system-ui, -apple-system, "Segoe UI", "Noto Sans KR", "Noto Sans JP", sans-serif;
}

.bar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 12px;
  padding: 10px 16px;
  border-bottom: 1px solid var(--line);
  background: var(--card);
}

.brand { font-weight: 600; font-size: 15px; }

main { max-width: 640px; margin: 0 auto; padding: 16px 16px 48px; }

h1 { font-size: 22px; margin: 8px 0; }
h2 { font-size: 17px; margin: 14px 0 6px; }
.card h2:first-child { margin-top: 0; }

.card {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 16px;
  margin: 16px 0;
}

ul { padding-left: 20px; margin: 4px 0; }
li { margin: 4px 0; }
.note { color: var(--muted); font-size: 14px; }

.providers { display: grid; gap: 10px; }

button {
  min-height: 48px;
  padding: 10px 16px;
  border-radius: 10px;
  border: 1px solid var(--line);
  background: var(--accent);
  color: #fff;
  font: inherit;
  font-weight: 600;
  cursor: pointer;
}
button:disabled { opacity: 0.45; cursor: not-allowed; }
button:focus-visible, input:focus-visible, select:focus-visible, textarea:focus-visible {
  outline: 3px solid var(--accent);
  outline-offset: 2px;
}
.provider.kakao { background: var(--kakao); color: #191919; }
.provider.google { background: #fff; color: #1f1f1f; }
.provider.apple { background: #000; color: #fff; }
.danger { background: var(--danger); width: 100%; margin-top: 10px; }
.link { background: none; color: var(--accent); border: none; padding: 8px 0; min-height: 44px; }

form { display: grid; gap: 12px; }
label { display: grid; gap: 4px; font-size: 15px; }
label.check { display: flex; align-items: center; gap: 10px; min-height: 44px; }
label.check input { width: 22px; height: 22px; }
input, select, textarea {
  font: inherit;
  padding: 10px;
  border-radius: 8px;
  border: 1px solid var(--line);
  background: var(--bg);
  color: var(--text);
  width: 100%;
  min-height: 44px;
}

.message {
  padding: 12px 14px;
  border-radius: 10px;
  background: var(--card);
  border: 1px solid var(--accent);
}

dl { display: grid; grid-template-columns: auto 1fr; gap: 6px 12px; }
dd { margin: 0; }
.code { font-family: ui-monospace, Consolas, monospace; word-break: break-all; user-select: all; }

.sr-only {
  position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap;
}

.lang select { width: auto; min-height: 40px; padding: 6px 8px; }

.foot {
  max-width: 640px;
  margin: 0 auto;
  padding: 8px 16px 32px;
  color: var(--muted);
  font-size: 14px;
}
.foot p { margin: 4px 0; }
.foot a { color: var(--accent); }