body {
  font-family: sans-serif;
  margin: 24px;
}

/* header用CSS */
.app-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
}


#monthFilter {
  appearance: none;         /* ← 重要 */
  -webkit-appearance: none;
  -moz-appearance: none;

  padding: 10px 32px 10px 12px;
  border-radius: 8px;
  border: 1px solid #ddd;
  background: #fff;

  font-size: inherit;
  cursor: pointer;
}

/* control area用CSS */
.control-area {
  display: flex;
  gap: 8px;
  font-size: 14px;
  align-items: center;
  justify-content: flex-end;
}

/* file upload用CSS */
.file-button {
  display: inline-block;
  padding: 10px 14px;
  border-radius: 8px;
  background: #0ea5e9;
  color: #fff;
  font-weight: bold;
  cursor: pointer;
  text-align: center;
}

.file-button input {
  display: none;
}

/* download button用CSS */
.download-button {
  display: inline-block;
  padding: 10px 14px;
  border-radius: 8px;
  background: #f3f4f6;
  color: #111827;
  border: 1px solid #ddd;
  font-weight: bold;
  text-decoration: none;
  text-align: center;
}


/* top panel用CSS */
.top-panel {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
  padding: 12px;
  margin: 12px 0;
  border: 1px solid #ddd;
  border-radius: 10px;
  background: #fafafa;
}

.summary-area {
  min-width: 180px;
}

.summary-label {
  font-size: 12px;
  color: #666;
}

.summary-value {
  font-size: 24px;
  font-weight: bold;
}


/* detail table用CSS */
.detail-section {
  margin-top: 24px;
}

.detail-section h2 {
  font-size: 18px;
  margin-bottom: 12px;
}

.table-wrapper {
  width: 100%;
  overflow-x: auto;
}

.detail-table {
  width: 100%;
  min-width: 560px;
  border-collapse: collapse;
  font-size: 14px;
}

.detail-table th,
.detail-table td {
  padding: 8px 10px;
  border: 1px solid #ddd;
  text-align: left;
  white-space: nowrap;
}

.detail-table th {
  background: #f3f4f6;
  font-weight: bold;
}

.detail-table tbody tr:nth-child(even) {
  background: #fafafa;
}

/* footer */
.app-credit {
  color: #666;
}

.footer-separator {
  display: none;
}

/* app actions */
.app-actions {
  color: #555;
}

@media (max-width: 600px) {
  body {
    margin: 16px;
  }

  .app-header {
    flex-direction: column;
    align-items: stretch;
    gap: 12px;
  }

  .app-header h1 {
    margin: 0;
    font-size: 28px;
  }

  .control-area {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 8px;
    width: 100%;
    font-size: 15px;
  }

  #monthFilter {
    grid-column: 1 / -1;
    width: 100%;
    box-sizing: border-box;
    font-size: 16px;
  }

  .file-button,
  .download-button {
    width: 100%;
    box-sizing: border-box;
    padding: 12px 8px;
    font-size: 14px;
    line-height: 1.2;
  }

  .top-panel {
    flex-direction: column;
    align-items: stretch;
  }

  .summary-value {
    font-size: 22px;
  }

  .detail-section h2 {
    font-size: 16px;
  }
}