* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  background: #f0f4f8;
  color: #333;
  min-height: 100vh;
}

.container {
  max-width: 640px;
  margin: 0 auto;
  padding: 16px;
}

h1 {
  font-size: 1.4rem;
  text-align: center;
  margin-bottom: 16px;
  color: #1565C0;
}

h2 {
  font-size: 1rem;
  margin-bottom: 8px;
  color: #c62828;
}

.card {
  background: #fff;
  border-radius: 10px;
  padding: 14px 16px;
  margin-bottom: 12px;
  box-shadow: 0 1px 4px rgba(0,0,0,0.08);
}

label {
  display: block;
  font-size: 0.82rem;
  color: #666;
  margin-bottom: 6px;
  font-weight: 600;
}

.row {
  display: flex;
  gap: 8px;
}

input[type="text"] {
  flex: 1;
  padding: 9px 12px;
  border: 1.5px solid #ccc;
  border-radius: 7px;
  font-size: 0.95rem;
  outline: none;
  transition: border-color 0.2s;
}

input[type="text"]:focus {
  border-color: #2196F3;
}

.btn-primary {
  padding: 9px 16px;
  background: #2196F3;
  color: #fff;
  border: none;
  border-radius: 7px;
  font-size: 0.9rem;
  cursor: pointer;
  white-space: nowrap;
  transition: background 0.2s;
}

.btn-primary:hover {
  background: #1976D2;
}

.current-month {
  margin-top: 8px;
  font-size: 0.95rem;
  font-weight: 700;
  color: #1565C0;
}

/* フィルター */
.filter-bar {
  display: flex;
  gap: 8px;
  margin-bottom: 10px;
}

.filter-btn {
  flex: 1;
  padding: 8px 4px;
  border: 1.5px solid #ddd;
  border-radius: 7px;
  background: #fff;
  color: #555;
  font-size: 0.85rem;
  cursor: pointer;
  transition: all 0.2s;
}

.filter-btn.active {
  background: #2196F3;
  color: #fff;
  border-color: #2196F3;
}

/* 集計 */
.summary {
  display: flex;
  gap: 12px;
  background: #fff;
  border-radius: 10px;
  padding: 10px 16px;
  margin-bottom: 12px;
  box-shadow: 0 1px 4px rgba(0,0,0,0.08);
  font-size: 0.88rem;
  color: #555;
}

.summary .paid strong { color: #2e7d32; }
.summary .unpaid strong { color: #c62828; }

/* 会員リスト */
.member-list {
  display: flex;
  flex-direction: column;
  gap: 8px;
  margin-bottom: 12px;
}

.member-item {
  display: flex;
  align-items: center;
  background: #fff;
  border-radius: 10px;
  padding: 12px 14px;
  box-shadow: 0 1px 4px rgba(0,0,0,0.08);
  gap: 10px;
  transition: opacity 0.15s;
}

.member-item.paid {
  border-left: 5px solid #4CAF50;
}

.member-item.unpaid {
  border-left: 5px solid #f44336;
}

.member-name {
  flex: 1;
  font-size: 0.97rem;
  font-weight: 600;
}

.toggle-btn {
  padding: 6px 14px;
  border-radius: 20px;
  border: none;
  font-size: 0.82rem;
  cursor: pointer;
  font-weight: 700;
  transition: background 0.2s;
}

.member-item.paid .toggle-btn {
  background: #e8f5e9;
  color: #2e7d32;
}

.member-item.unpaid .toggle-btn {
  background: #ffebee;
  color: #c62828;
}

.toggle-btn:hover {
  filter: brightness(0.92);
}

.delete-btn {
  background: none;
  border: none;
  color: #bbb;
  font-size: 1.1rem;
  cursor: pointer;
  padding: 4px 6px;
  border-radius: 5px;
  transition: color 0.2s;
}

.delete-btn:hover {
  color: #e53935;
}

.empty-msg {
  text-align: center;
  color: #aaa;
  font-size: 0.9rem;
  padding: 24px 0;
}

/* 未回収一覧 */
.unpaid-section {
  border: 1.5px solid #ffcdd2;
}

.unpaid-section ul {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.unpaid-section li {
  font-size: 0.93rem;
  padding: 6px 10px;
  background: #ffebee;
  border-radius: 6px;
  color: #c62828;
  font-weight: 600;
}

@media (max-width: 400px) {
  h1 { font-size: 1.2rem; }
  .summary { flex-wrap: wrap; gap: 8px; }
  .filter-bar { flex-direction: column; }
  .filter-btn { padding: 8px; }
}