/* =====================================================
   css/common.css
   共通スタイル・CSS 変数・ユーティリティ
   ===================================================== */

:root {
  --color-primary: #4f46e5;
  --color-primary-hover: #4338ca;
  --color-success: #16a34a;
  --color-success-bg: #dcfce7;
  --color-danger: #dc2626;
  --color-danger-bg: #fee2e2;
  --color-warning: #d97706;
  --color-warning-bg: #fef3c7;
  --color-gray-50: #f9fafb;
  --color-gray-100: #f3f4f6;
  --color-gray-200: #e5e7eb;
  --color-gray-300: #d1d5db;
  --color-gray-400: #9ca3af;
  --color-gray-500: #6b7280;
  --color-gray-600: #4b5563;
  --color-gray-700: #374151;
  --color-gray-800: #1f2937;
  --color-gray-900: #111827;
  --color-white: #ffffff;

  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 12px;

  --shadow-sm: 0 1px 2px rgba(0,0,0,0.05);
  --shadow-md: 0 4px 6px -1px rgba(0,0,0,0.1), 0 2px 4px -1px rgba(0,0,0,0.06);
  --shadow-lg: 0 10px 15px -3px rgba(0,0,0,0.1), 0 4px 6px -2px rgba(0,0,0,0.05);

  --font-sans: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Hiragino Kaku Gothic ProN', 'Hiragino Sans', Meiryo, sans-serif;
}

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

body {
  font-family: var(--font-sans);
  font-size: 14px;
  line-height: 1.6;
  color: var(--color-gray-800);
  background-color: var(--color-gray-50);
  min-height: 100vh;
}

/* ボタン */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  padding: 8px 16px;
  border: none;
  border-radius: var(--radius-md);
  font-size: 14px;
  font-weight: 500;
  cursor: pointer;
  transition: background-color 0.15s, opacity 0.15s;
  white-space: nowrap;
}

.btn:disabled {
  opacity: 0.6;
  cursor: not-allowed;
}

.btn-primary {
  background-color: var(--color-primary);
  color: var(--color-white);
}

.btn-primary:hover:not(:disabled) {
  background-color: var(--color-primary-hover);
}

.btn-secondary {
  background-color: var(--color-gray-200);
  color: var(--color-gray-700);
}

.btn-secondary:hover:not(:disabled) {
  background-color: var(--color-gray-300);
}

.btn-danger {
  background-color: var(--color-danger);
  color: var(--color-white);
}

.btn-danger:hover:not(:disabled) {
  background-color: #b91c1c;
}

.btn-sm {
  padding: 4px 10px;
  font-size: 12px;
}

/* ヘッダー */
.header {
  background-color: var(--color-white);
  border-bottom: 1px solid var(--color-gray-200);
  padding: 0 24px;
  height: 56px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: var(--shadow-sm);
}

.header-title {
  font-size: 16px;
  font-weight: 600;
  color: var(--color-gray-900);
}

.header-user {
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 14px;
  color: var(--color-gray-600);
}

/* メインコンテンツ */
.main {
  max-width: 1200px;
  margin: 0 auto;
  padding: 24px 16px;
}

/* カード */
.card {
  background-color: var(--color-white);
  border: 1px solid var(--color-gray-200);
  border-radius: var(--radius-lg);
  padding: 20px;
  box-shadow: var(--shadow-sm);
}

/* フォーム */
.form-group {
  margin-bottom: 16px;
}

.form-label {
  display: block;
  font-size: 13px;
  font-weight: 500;
  color: var(--color-gray-700);
  margin-bottom: 6px;
}

.form-input {
  width: 100%;
  padding: 8px 12px;
  border: 1px solid var(--color-gray-300);
  border-radius: var(--radius-md);
  font-size: 14px;
  font-family: var(--font-sans);
  transition: border-color 0.15s, box-shadow 0.15s;
  background-color: var(--color-white);
  color: var(--color-gray-800);
}

.form-input:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px rgba(79, 70, 229, 0.1);
}

textarea.form-input {
  resize: vertical;
  min-height: 80px;
}

/* アラート */
.alert {
  padding: 12px 16px;
  border-radius: var(--radius-md);
  font-size: 13px;
  margin-bottom: 16px;
}

.alert-error {
  background-color: var(--color-danger-bg);
  color: var(--color-danger);
  border: 1px solid #fca5a5;
}

.alert-success {
  background-color: var(--color-success-bg);
  color: var(--color-success);
  border: 1px solid #86efac;
}

/* 期限切れ */
.overdue {
  color: var(--color-danger);
}

.overdue-badge {
  display: inline-block;
  background-color: var(--color-danger-bg);
  color: var(--color-danger);
  font-size: 11px;
  font-weight: 600;
  padding: 1px 6px;
  border-radius: 9999px;
  margin-left: 6px;
}

/* ローディング */
.loading {
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 40px;
  color: var(--color-gray-400);
  font-size: 14px;
  gap: 8px;
}

.spinner {
  width: 18px;
  height: 18px;
  border: 2px solid var(--color-gray-200);
  border-top-color: var(--color-primary);
  border-radius: 50%;
  animation: spin 0.6s linear infinite;
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

/* 空状態 */
.empty-state {
  text-align: center;
  padding: 48px 24px;
  color: var(--color-gray-400);
}

.empty-state p {
  font-size: 14px;
  margin-top: 8px;
}

/* モーダルオーバーレイ */
.modal-overlay {
  display: none;
  position: fixed;
  inset: 0;
  background-color: rgba(0, 0, 0, 0.5);
  z-index: 200;
  align-items: center;
  justify-content: center;
  padding: 16px;
}

.modal-overlay.active {
  display: flex;
}

.modal {
  background-color: var(--color-white);
  border-radius: var(--radius-lg);
  padding: 24px;
  width: 100%;
  max-width: 480px;
  box-shadow: var(--shadow-lg);
}

.modal-title {
  font-size: 16px;
  font-weight: 600;
  color: var(--color-gray-900);
  margin-bottom: 20px;
}

.modal-actions {
  display: flex;
  gap: 8px;
  justify-content: flex-end;
  margin-top: 20px;
}

/* タブ */
.tabs {
  display: flex;
  border-bottom: 2px solid var(--color-gray-200);
  margin-bottom: 24px;
  gap: 0;
}

.tab-btn {
  padding: 10px 20px;
  border: none;
  background: none;
  font-size: 14px;
  font-weight: 500;
  color: var(--color-gray-500);
  cursor: pointer;
  border-bottom: 2px solid transparent;
  margin-bottom: -2px;
  transition: color 0.15s, border-color 0.15s;
}

.tab-btn:hover {
  color: var(--color-gray-700);
}

.tab-btn.active {
  color: var(--color-primary);
  border-bottom-color: var(--color-primary);
}

.tab-panel {
  display: none;
}

.tab-panel.active {
  display: block;
}

/* フッター */
.footer {
  text-align: center;
  padding: 16px;
  margin-top: 40px;
  font-size: 12px;
  color: var(--color-gray-400);
}

.footer a {
  color: var(--color-gray-400);
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  gap: 4px;
}

.footer a:hover {
  color: var(--color-gray-600);
}

.footer img {
  height: 14px;
  vertical-align: middle;
}

/* レスポンシブ */
@media (max-width: 640px) {
  .main {
    padding: 16px 12px;
  }

  .header {
    padding: 0 16px;
  }
}