:root {
  --primary-color: #46178f;
  --hover-color: #311066;
  --bg-color: #f0f2f5;
  --error-color: #dc3545;
  --success-color: #28a745;
}

body {
  font-family: 'Pretendard', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  background-color: var(--bg-color);
  margin: 0; padding: 20px;
  display: flex; justify-content: center;
}

.container {
  background: white; padding: 30px; border-radius: 15px;
  box-shadow: 0 10px 25px rgba(0,0,0,0.1);
  width: 100%; max-width: 650px;
}

h1 { text-align: center; color: var(--primary-color); margin-bottom: 25px; }

/* 탭 스타일 */
.tabs { display: flex; margin-bottom: 25px; border-bottom: 2px solid #eee; }
.tab-btn {
  flex: 1; padding: 12px; border: none; background: none; cursor: pointer;
  font-size: 16px; font-weight: bold; color: #777; transition: 0.3s;
}
.tab-btn.active { color: var(--primary-color); border-bottom: 3px solid var(--primary-color); }
.tab-content { display: none; }
.tab-content.active { display: block; }

/* 폼 스타일 */
.form-group { margin-bottom: 18px; }
.row { display: flex; gap: 15px; }
.col { flex: 1; }
label { display: block; font-weight: 600; margin-bottom: 8px; font-size: 14px; }
input, textarea, select {
  width: 100%; padding: 12px; border: 1px solid #ddd; border-radius: 8px; box-sizing: border-box;
}

/* 주제 추천 버튼 스타일 */
.topic-buttons { display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 12px; }
.topic-btn {
  padding: 8px 14px; font-size: 13px; font-weight: 600; background-color: #f0ebf8; color: var(--primary-color);
  border: 1px solid #e0d5f2; border-radius: 20px; cursor: pointer; transition: all 0.2s;
}
.topic-btn:hover {
  background-color: var(--primary-color); color: white; border-color: var(--primary-color);
}

/* 난이도 섹션 */
.difficulty-section {
  background: #f9f7fd; padding: 15px; border-radius: 10px; margin-bottom: 20px;
  border: 1px solid #e0d5f2;
}
.diff-inputs { display: flex; gap: 10px; margin-top: 10px; align-items: center; }
.diff-inputs input { width: 60px; text-align: center; padding: 5px; }
.diff-status { font-size: 12px; margin-top: 8px; font-weight: bold; }

/* 드래그 앤 드랍 */
.drop-zone {
  border: 2px dashed #ccc; padding: 25px; text-align: center; border-radius: 8px;
  background: #fafafa; cursor: pointer; transition: 0.3s;
}
.drop-zone.dragover { border-color: var(--primary-color); background: #f0ebf8; }
.file-list { margin-top: 10px; font-size: 12px; color: var(--primary-color); font-weight: bold; }

.btn-submit {
  width: 100%; padding: 15px; background: var(--primary-color); color: white;
  border: none; border-radius: 8px; font-size: 17px; font-weight: bold; cursor: pointer;
  transition: 0.2s;
}
.btn-submit:hover { background: var(--hover-color); }
.btn-submit:disabled { background: #ccc; cursor: not-allowed; }

.status-message { text-align: center; margin-top: 15px; font-weight: bold; min-height: 20px; }
.hint { font-size: 12px; color: #666; margin-top: 5px; }