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

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  background: #f0f2f5;
  color: #333;
  min-height: 100vh;
}

.container {
  max-width: 900px;
  margin: 0 auto;
  padding: 16px;
}

header {
  background: #2c3e50;
  color: #fff;
  padding: 16px;
  border-radius: 12px;
  margin-bottom: 16px;
}

header h1 {
  font-size: 1.4rem;
  margin-bottom: 12px;
}

.settings-row {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
}

.settings-row label {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.85rem;
}

.settings-row input[type="number"] {
  width: 64px;
  padding: 4px 8px;
  border: none;
  border-radius: 6px;
  font-size: 0.9rem;
  text-align: center;
}

.add-table-row {
  display: flex;
  gap: 8px;
  margin-bottom: 12px;
}

.add-table-row input {
  flex: 1;
  padding: 10px 14px;
  border: 2px solid #ddd;
  border-radius: 8px;
  font-size: 1rem;
}

.add-table-row input:focus {
  outline: none;
  border-color: #2c3e50;
}

.add-table-row button {
  padding: 10px 20px;
  background: #2c3e50;
  color: #fff;
  border: none;
  border-radius: 8px;
  font-size: 1rem;
  cursor: pointer;
  white-space: nowrap;
}

.add-table-row button:hover {
  background: #3d5166;
}

.summary-row {
  background: #fff;
  border-radius: 8px;
  padding: 10px 14px;
  margin-bottom: 16px;
  font-size: 0.9rem;
  color: #555;
  box-shadow: 0 1px 4px rgba(0,0,0,0.08);
}

.table-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(160px, 1fr));
  gap: 12px;
}

.table-card {
  background: #fff;
  border-radius: 12px;
  padding: 16px;
  box-shadow: 0 2px 8px rgba(0,0,0,0.1);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 10px;
  border: 3px solid transparent;
  transition: border-color 0.3s, background 0.3s;
  position: relative;
}

/* 空席 */
.table-card.vacant {
  border-color: #bdc3c7;
}

/* 着席中（正常） */
.table-card.occupied {
  border-color: #27ae60;
  background: #f0fff5;
}

/* 警告（30分超） */
.table-card.warning {
  border-color: #f39c12;
  background: #fffbf0;
}

/* 超過（60分超） */
.table-card.alert {
  border-color: #e74c3c;
  background: #fff5f5;
  animation: pulse 1.5s infinite;
}

@keyframes pulse {
  0%, 100% { box-shadow: 0 2px 8px rgba(231,76,60,0.2); }
  50% { box-shadow: 0 2px 16px rgba(231,76,60,0.5); }
}

.card-name {
  font-size: 1.1rem;
  font-weight: bold;
  text-align: center;
  word-break: break-all;
}

.card-status {
  font-size: 0.8rem;
  color: #777;
}

.card-time {
  font-size: 1.6rem;
  font-weight: bold;
  font-variant-numeric: tabular-nums;
  letter-spacing: 1px;
}

.table-card.vacant .card-time {
  color: #bbb;
}

.table-card.occupied .card-time {
  color: #27ae60;
}

.table-card.warning .card-time {
  color: #f39c12;
}

.table-card.alert .card-time {
  color: #e74c3c;
}

.card-btn {
  width: 100%;
  padding: 8px;
  border: none;
  border-radius: 8px;
  font-size: 0.95rem;
  cursor: pointer;
  font-weight: bold;
}

.btn-seat {
  background: #27ae60;
  color: #fff;
}

.btn-seat:hover {
  background: #219a52;
}

.btn-leave {
  background: #e74c3c;
  color: #fff;
}

.btn-leave:hover {
  background: #c0392b;
}

.btn-delete {
  position: absolute;
  top: 8px;
  right: 8px;
  background: none;
  border: none;
  font-size: 1rem;
  cursor: pointer;
  color: #bbb;
  line-height: 1;
  padding: 2px;
}

.btn-delete:hover {
  color: #e74c3c;
}

.empty-message {
  grid-column: 1 / -1;
  text-align: center;
  color: #aaa;
  padding: 40px 0;
  font-size: 0.95rem;
}

@media (max-width: 480px) {
  .table-grid {
    grid-template-columns: repeat(auto-fill, minmax(140px, 1fr));
    gap: 10px;
  }

  .card-time {
    font-size: 1.4rem;
  }
}