:root {
  --ink: #1d1d1f;
  --muted: #6e6e73;
  --line: #d1d1d6;
  --paper: #ffffff;
  --ground: #f5f5f7;
  --error: #c62828;
  color-scheme: light dark;
}
@media (prefers-color-scheme: dark) {
  :root { --ink: #f5f5f7; --muted: #a1a1a6; --line: #3a3a3c; --paper: #1c1c1e; --ground: #000000; --error: #ff6b6b; }
}
* { box-sizing: border-box; }
body {
  margin: 0;
  min-height: 100vh;
  display: grid;
  place-items: center;
  padding: 16px;
  background: var(--ground);
  color: var(--ink);
  font: 15px/1.5 "DM Sans", system-ui, -apple-system, "Segoe UI", "Microsoft JhengHei", sans-serif;
}
.card {
  width: 100%;
  max-width: 360px;
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: 14px;
  padding: 28px 24px;
}
h1 { margin: 0 0 4px; font-size: 20px; font-weight: 600; }
.hint { margin: 0 0 20px; color: var(--muted); }
label { display: block; margin-bottom: 14px; font-size: 13px; color: var(--muted); }
input {
  display: block;
  width: 100%;
  margin-top: 6px;
  padding: 10px 12px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--paper);
  color: var(--ink);
  font: inherit;
}
input:focus { outline: 2px solid #0a84ff; outline-offset: 1px; }
button {
  width: 100%;
  margin-top: 6px;
  padding: 11px 12px;
  border: 0;
  border-radius: 8px;
  background: var(--ink);
  color: var(--paper);
  font: inherit;
  font-weight: 600;
  cursor: pointer;
}
button:disabled { opacity: 0.6; cursor: default; }
.error { margin: 0 0 10px; color: var(--error); font-size: 13px; }
.notice { margin: 0 0 14px; padding: 10px 12px; border-radius: 8px; background: var(--ground); border: 1px solid var(--line); font-size: 13px; }
.google {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  width: 100%;
  padding: 10px 12px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--paper);
  color: var(--ink);
  font-weight: 600;
  text-decoration: none;
}
.google:hover { background: var(--ground); }
.divider { display: flex; align-items: center; gap: 10px; margin: 18px 0; color: var(--muted); font-size: 12px; }
.divider::before, .divider::after { content: ""; flex: 1; border-top: 1px solid var(--line); }
[hidden] { display: none !important; }
.guest-button { width: 100%; padding: 10px 12px; border: 1px solid var(--line); border-radius: 8px; background: var(--paper); color: var(--ink); font-weight: 600; }
.guest-button:hover { background: var(--ground); }
#guest-entry[hidden] { display: none; }