/* 최소한의 모바일 반응형 리셋 */
* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  font-family: sans-serif;
  background-color: #f5f5f5;
  color: #333;
}

.view {
  display: none;
  padding: 20px;
  max-width: 600px;
  margin: 0 auto;
}

.view.active {
  display: block;
}

/* 폼 및 입력창 레이아웃 */
form {
  display: flex;
  flex-direction: column;
  gap: 15px;
  margin-top: 20px;
}

input[type="tel"] {
  padding: 10px;
  font-size: 16px;
  border: 1px solid #ccc;
  border-radius: 4px;
}

button {
  padding: 12px;
  font-size: 16px;
  background-color: #007bff;
  color: white;
  border: none;
  border-radius: 4px;
  cursor: pointer;
}

button:hover {
  background-color: #0056b3;
}

.close-btn {
  background-color: #6c757d;
  margin-top: 10px;
  width: 100%;
}

.close-btn:hover {
  background-color: #5a6268;
}

.submit-btn {
  background-color: #28a745;
  width: 100%;
}

.submit-btn:hover {
  background-color: #218838;
}

/* 모달 레이아웃 */
.modal {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background-color: rgba(0,0,0,0.5);
  display: flex;
  justify-content: center;
  align-items: center;
  z-index: 1000;
}

.modal.hidden {
  display: none;
}

.modal-content {
  background-color: white;
  padding: 20px;
  border-radius: 8px;
  width: 90%;
  max-width: 400px;
  max-height: 90vh;
  overflow-y: auto;
  display: flex;
  flex-direction: column;
}

/* 학생 선택 리스트 */
#student-list {
  list-style: none;
  margin-top: 15px;
  margin-bottom: 20px;
}

#student-list li {
  padding: 15px;
  border-bottom: 1px solid #eee;
  cursor: pointer;
}

#student-list li:hover {
  background-color: #f9f9f9;
}

/* 숙제 목록 */
#homework-list {
  list-style: none;
  margin-top: 20px;
}

.homework-item {
  background: white;
  padding: 15px;
  border-radius: 8px;
  margin-bottom: 10px;
  box-shadow: 0 1px 3px rgba(0,0,0,0.1);
  cursor: pointer;
}

.homework-item h3 {
  margin-bottom: 5px;
}

/* 동적 업로드 슬롯 그리드 */
.slots-container {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin: 20px 0;
}

.upload-slot {
  width: 80px;
  height: 80px;
  border: 2px dashed #ccc;
  border-radius: 8px;
  display: flex;
  justify-content: center;
  align-items: center;
  position: relative;
  overflow: hidden;
}

.file-label {
  width: 100%;
  height: 100%;
  display: flex;
  justify-content: center;
  align-items: center;
  font-size: 24px;
  color: #999;
  cursor: pointer;
}

.file-input {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  opacity: 0;
  cursor: pointer;
}

.preview-img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}