/* デフォルトの背景色を変数で指定 */
body {
  background-color: var(--page-bg);
}

main {
  max-width: 800px;
  margin: 40px auto;
  padding: 0 20px;
}

h1 {
  text-align: center;
  margin-bottom: 30px;
}

.back-link {
  max-width: 800px;
  margin: 0 auto 20px auto;
  padding: 0 20px;
  text-align: left;
}

.back-link a {
  color: #4a90e2;
  text-decoration: none;
  font-weight: 600;
}

.back-link a:hover {
  text-decoration: underline;
}

#search-input {
  display: block;
  width: 100%;
  max-width: 800px;
  margin: 0 auto 20px auto;
  padding: 10px;
  font-size: 16px;
  border-radius: 8px;
  border: 1px solid #ccc;
  box-sizing: border-box;
}

/* フィルター用チェックボックス配置 */
.filter-options {
  max-width: 800px;
  margin: 0 auto 20px auto;
  padding: 0 20px;
  display: flex;
  gap: 20px;
  align-items: center;
}

.filter-options label {
  font-size: 0.95rem;
  cursor: pointer;
}

ul.course-list {
  list-style: none;
  padding: 0;
  max-width: 800px;
  margin: 0 auto;
}

ul.course-list li {
  background-color: #f9f9f9;
  border: 1px solid #ddd;
  border-radius: 10px;
  padding: 15px 20px;
  margin-bottom: 15px;
  transition: background-color 0.3s ease, border-color 0.3s ease;
  position: relative;
}

ul.course-list li:hover {
  background-color: #e0f0ff;
}

ul.course-list li a {
  text-decoration: none;
  color: #333;
  font-weight: 600;
  display: block;
  font-size: 1.1em;
}

ul.course-list li p {
  margin: 8px 0 0 0;
  color: #666;
  font-size: 0.9em;
}

ul.course-list li.no-courses-message {
  text-align: center;
  color: #999;
  font-style: italic;
  cursor: default;
  pointer-events: none;
}

ul.course-list li.no-courses-message:hover {
  background-color: #f9f9f9;
}

.course-description {
  text-align: center;
  margin: 20px auto;
  max-width: 600px;
  line-height: 1.8;
  font-size: 1rem;
  color: #333;
}

/* ✅ ステータス共通ラベル */
.status-label {
  position: absolute;
  top: 12px;
  right: 16px;
  padding: 4px 8px;
  font-size: 0.75em;
  font-weight: bold;
  border-radius: 12px;
  color: white;
  user-select: none;
}

/* ✅ 登録済み */
ul.course-list li.registered {
  border: 2px solid #4caf50;
  background-color: #e8f5e9;
}

ul.course-list li.registered .status-label {
  background-color: #4caf50;
}

/* ✅ 修了：銀 */
ul.course-list li.completed-silver {
  border: 2px solid silver;
  background-color: #f0f0f0;
}

ul.course-list li.completed-silver .status-label {
  background-color: silver;
}

/* ✅ 修了：金 */
ul.course-list li.completed-gold {
  border: 2px solid goldenrod;
  background-color: #fff8dc;
}

ul.course-list li.completed-gold .status-label {
  background-color: goldenrod;
}

/* モバイル対応 */
@media screen and (max-width: 600px) {
  main {
    margin: 20px 10px;
    padding: 0 10px;
  }

  h1 {
    font-size: 1.5em;
    margin-bottom: 20px;
  }

  .back-link {
    padding: 0 10px;
  }

  #search-input {
    font-size: 14px;
    padding: 8px;
  }

  ul.course-list li {
    padding: 12px 15px;
  }

  ul.course-list li a {
    font-size: 1em;
  }

  ul.course-list li p {
    font-size: 0.85em;
  }

  .course-description {
    max-width: 100%;
    font-size: 0.95rem;
    padding: 0 10px;
    line-height: 1.6;
  }

  .status-label {
    top: 10px;
    right: 12px;
    font-size: 0.65em;
    padding: 2px 6px;
  }

  .filter-options {
    flex-direction: column;
    gap: 10px;
    padding: 0 10px;
  }
}

/* 任意：登録ボタン非表示用 */
.enroll-button {
  display: none;
}