:root {
  --surface: #fcfcfb;
  --surface-2: #f1f1ef;
  --ink: #1f2937;
  --ink-muted: #6b7280;
  --accent: #2563eb;
  --danger: #dc2626;
  --border: #e5e7eb;
}
@media (prefers-color-scheme: dark) {
  :root {
    --surface: #1a1a19;
    --surface-2: #262625;
    --ink: #e7e5e4;
    --ink-muted: #a8a29e;
    --border: #3f3f3e;
  }
}
* { box-sizing: border-box; }
body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, 'Hiragino Sans', sans-serif;
  background: var(--surface);
  color: var(--ink);
  max-width: 720px;
  margin-inline: auto;
  padding: 0 16px 48px;
}
.app-header {
  position: sticky;
  top: 0;
  display: flex;
  align-items: center;
  gap: 16px;
  padding: 12px 0;
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  z-index: 10;
}
.brand { font-weight: 700; margin-right: auto; }
.stat strong, .stat span { font-size: 1.1em; }
.level { display: flex; align-items: center; gap: 8px; }
.level-bar-track {
  width: 80px; height: 8px; border-radius: 4px;
  background: var(--surface-2); overflow: hidden;
}
.level-bar { height: 100%; background: var(--accent); border-radius: 4px; transition: width 0.6s ease; }
.nav { display: flex; gap: 16px; padding: 8px 0; }
.nav a { color: var(--ink-muted); text-decoration: none; }
.nav a:hover { color: var(--accent); }
h2 { font-size: 0.9rem; color: var(--ink-muted); margin: 24px 0 8px; }
.items { list-style: none; margin: 0; padding: 0; }
.items li {
  display: flex; align-items: center; gap: 12px;
  padding: 10px 12px; border: 1px solid var(--border);
  border-radius: 8px; margin-bottom: 8px; background: var(--surface);
}
.items li.overdue { border-color: var(--danger); }
.items li.done { opacity: 0.55; }
.items li.done .name { text-decoration: line-through; }
.check {
  width: 28px; height: 28px; border-radius: 50%;
  border: 2px solid var(--accent); background: transparent; cursor: pointer; flex-shrink: 0;
}
.check:hover { background: var(--accent); }
.name { flex: 1; }
.meta { color: var(--ink-muted); font-size: 0.85em; }
.pts { color: var(--accent); font-weight: 600; }
.badge {
  font-size: 0.75em; padding: 2px 8px; border-radius: 999px;
  background: var(--surface-2); color: var(--ink-muted);
}
.empty { color: var(--ink-muted); text-align: center; padding: 24px 0; }
.chart-label { fill: var(--ink-muted); font-size: 10px; }
.chart-value { fill: var(--ink); font-size: 11px; font-weight: 600; }

/* レベルアップ演出 */
.levelup-overlay {
  position: fixed; inset: 0; z-index: 100;
  display: flex; align-items: center; justify-content: center;
  background: radial-gradient(circle at center, rgba(37, 99, 235, 0.25), rgba(0, 0, 0, 0.75));
  animation: flash 0.3s ease;
  cursor: pointer;
}
.levelup-title {
  font-size: 3rem; font-weight: 900; color: #fff; text-align: center;
  animation: bounce-in 0.5s cubic-bezier(0.34, 1.56, 0.64, 1);
}
.levelup-level {
  font-size: 4.5rem; font-weight: 900; color: #fbbf24; text-align: center;
  animation: bounce-in 0.6s cubic-bezier(0.34, 1.56, 0.64, 1);
}
@keyframes bounce-in {
  0% { transform: scale(0.2); opacity: 0; }
  100% { transform: scale(1); opacity: 1; }
}
@keyframes flash {
  0% { background: #fff; }
}
canvas.confetti { position: fixed; inset: 0; z-index: 101; pointer-events: none; }

/* フォーム(Task 12) */
form.item-form { display: grid; gap: 12px; max-width: 480px; }
form.item-form label { display: grid; gap: 4px; font-size: 0.85rem; color: var(--ink-muted); }
form.item-form input, form.item-form select, form.item-form textarea {
  padding: 8px; border: 1px solid var(--border); border-radius: 6px;
  background: var(--surface); color: var(--ink); font-size: 1rem;
}
form.item-form .weekday-picker { display: flex; gap: 8px; }
button.primary {
  padding: 10px 20px; border: none; border-radius: 8px;
  background: var(--accent); color: #fff; font-size: 1rem; cursor: pointer;
}
button.small {
  padding: 4px 12px; border: 1px solid var(--border); border-radius: 6px;
  background: transparent; color: var(--ink-muted); cursor: pointer;
}
.balance-hero { font-size: 2.5rem; font-weight: 800; margin: 16px 0; }
.balance-hero small { font-size: 1rem; color: var(--ink-muted); font-weight: 400; }
.lack { color: var(--ink-muted); font-size: 0.85em; }
.history-entry.spend .pts { color: var(--danger); }
.error-banner {
  background: color-mix(in srgb, var(--danger) 12%, var(--surface));
  color: var(--danger); padding: 8px 12px; border-radius: 8px; margin: 12px 0;
}
.auth-page { max-width: 360px; margin: 15vh auto 0; text-align: center; display: grid; gap: 16px; }
.auth-page .brand { font-size: 2rem; margin: 0; }
.auth-page .tagline { color: var(--ink-muted); margin: 0; }
.auth-page form { text-align: left; }

.account { display: flex; align-items: center; gap: 8px; }
.invite-url { width: 100%; padding: 8px; border: 1px solid var(--border); border-radius: 6px; background: var(--surface-2); color: var(--ink); }