:root {
  --paper: #ffffff;
  --line: #e3eaf6;
  --ink: #111111;
  --sub: #6b7280;
  --accent: #1f5bd8;
  --on-accent: #ffffff;
}

@media (prefers-color-scheme: dark) {
  :root {
    --paper: #000000;
    --line: #1c1c1f;
    --ink: #ffffff;
    --sub: #a1a1aa;
    --accent: #ffffff;
    --on-accent: #000000;
  }
}

* { box-sizing: border-box; }

body {
  margin: 0;
  min-height: 100vh;
  font-family: -apple-system, BlinkMacSystemFont, "Hiragino Sans", "Noto Sans JP", sans-serif;
  color: var(--ink);
  background-color: var(--paper);
  background-image:
    linear-gradient(var(--line) 1px, transparent 1px),
    linear-gradient(90deg, var(--line) 1px, transparent 1px);
  background-size: 20px 20px;
  background-position: -1px -1px;
}

main {
  max-width: 480px;
  min-height: 100vh;
  margin: 0 auto;
  padding: 64px 20px 40px;
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 12px;
}

.eyebrow { margin: 0; font-size: 15px; font-weight: 600; color: var(--accent); }
.logo { margin: 0; font-size: 80px; font-weight: 800; line-height: 1; letter-spacing: -0.03em; }
.bracket { font-weight: 300; color: var(--accent); }
.name { margin: 0; font-size: 40px; font-weight: 800; line-height: 1.2; }
.note { margin: 0; font-size: 15px; line-height: 1.7; color: var(--sub); }

.actions { margin-top: 32px; display: flex; flex-direction: column; gap: 10px; }

.button {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 54px;
  border-radius: 14px;
  background: var(--accent);
  color: var(--on-accent);
  font-size: 17px;
  font-weight: 600;
  text-decoration: none;
  border: none;
  cursor: pointer;
  width: 100%;
  font-family: inherit;
  padding: 0 16px;
  box-sizing: border-box;
}

.button:disabled,
.button[aria-disabled="true"] {
  opacity: 0.4;
  cursor: not-allowed;
  pointer-events: none;
}

.button-danger {
  background: #dc2626;
  color: #ffffff;
}

.button-danger:hover {
  background: #b91c1c;
}

.card {
  margin: 8px 0;
  padding: 16px 20px;
  border-radius: 14px;
  border: 1px solid var(--line);
  background-color: var(--paper);
}

.card ul {
  margin: 0;
  padding-left: 20px;
  color: var(--ink);
  font-size: 15px;
  line-height: 1.8;
}

.card-danger {
  border-color: #fca5a5;
  background-color: rgba(239, 68, 68, 0.05);
}

@media (prefers-color-scheme: dark) {
  .card-danger {
    border-color: #7f1d1d;
    background-color: rgba(239, 68, 68, 0.1);
  }
}

.status-message {
  margin: 16px 0;
  padding: 14px 18px;
  border-radius: 12px;
  font-size: 15px;
  line-height: 1.6;
}

.status-error {
  color: #dc2626;
  background-color: rgba(239, 68, 68, 0.1);
  border: 1px solid #fca5a5;
}

.status-success {
  color: #16a34a;
  background-color: rgba(22, 163, 74, 0.1);
  border: 1px solid #86efac;
  font-weight: 600;
}

footer { margin-top: 48px; font-size: 13px; color: var(--sub); }
footer a { color: var(--sub); }