/* --- 基础 & 重置 --- */
* { margin: 0; padding: 0; box-sizing: border-box; }
body { font-family: 'Helvetica Neue', sans-serif; background: #f9fafb; color: #333; }
.container { padding: 80px 16px 60px; max-width: 800px; margin: 0 auto; }

/* --- 头部 --- */
.header {
  position: fixed; top: 0; left: 0; width: 100%; height: 50px;
  background: #fff; box-shadow: 0 1px 4px rgba(0,0,0,0.1);
  display: flex; align-items: center; justify-content: space-between;
  padding: 0 16px; z-index: 100;
}
.header h1 { font-size: 1.4rem; color: #4a90e2; }
.header button { background: none; border: none; font-size: 1.4rem; cursor: pointer; }

/* --- 区块 & 隐藏 --- */
section { display: none; }
.section.active { display: block; }
.hidden { display: none; }

/* --- 标题 --- */
h2 { font-size: 1.3rem; margin-bottom: 12px; color: #4a90e2; }

/* --- 表单组 --- */
.form-group {
  margin-top: 8px;
  margin-bottom: 8px; /* 空出与分类的间距 */
}
textarea, input[type="text"], input[type="number"], select {
  width: 100%; padding: 10px; border: 1px solid #ddd;
  border-radius: 4px; font-size: 1rem; background: #fff;
}
textarea { resize: vertical; }

/* --- 按钮 --- */
button {
  display: inline-block; background: #4a90e2; color: #fff;
  border: none; padding: 10px 16px; font-size: 1rem;
  border-radius: 4px; cursor: pointer; transition: background 0.2s;
}
button:hover { background: #357abd; }

/* --- 文件上传 --- */
#image-upload-wrapper {
  display: flex; align-items: center; justify-content: space-between;
}
#image-input {
  flex: 1; margin-right: 12px;
}

/* --- 分类按钮组 --- */
.btn-group { margin-bottom: 16px; }
.btn-group button {
  margin-right: 8px; margin-bottom: 8px;
  background: #fff; color: #555; border: 1px solid #ccc;
  border-radius: 4px; padding: 6px 12px;
}
.btn-group button.active { background: #4a90e2; color: #fff; border-color: #4a90e2; }

/* --- 列表 & 预览图 --- */
ul { list-style: none; }
li {
  padding: 12px; border: 1px solid #eaeaea; border-radius: 4px;
  margin-bottom: 8px; display: flex; align-items: center;
}
li .preview {
  max-width: 60px; max-height: 60px; margin-right: 12px; border-radius: 4px;
}
li div { flex: 1; }

/* --- 切换开关 --- */
.toggle-switch {
  position: relative; display: inline-block; width: 40px; height: 20px;
  vertical-align: middle;
}
.toggle-switch input { opacity: 0; width: 0; height: 0; }
.slider {
  position: absolute; cursor: pointer; top: 0; left: 0; right: 0; bottom: 0;
  background-color: #ccc; border-radius: 20px; transition: .4s;
}
.slider:before {
  position: absolute; content: ""; height: 16px; width: 16px;
  left: 2px; bottom: 2px; background-color: white;
  border-radius: 50%; transition: .4s;
}
.toggle-switch input:checked + .slider { background-color: #4a90e2; }
.toggle-switch input:checked + .slider:before { transform: translateX(20px); }

/* --- Toast --- */
.toast {
  position: fixed; bottom: 70px; left: 50%; transform: translateX(-50%);
  background: rgba(0, 0, 0, 0.7); color: #fff;
  padding: 10px 20px; border-radius: 20px; opacity: 0;
  transition: opacity 0.3s;
}

/* --- 底部导航 --- */
.footer-nav {
  position: fixed; bottom: 0; left: 0; width: 100%; height: 50px;
  background: #fff; border-top: 1px solid #ddd;
  display: flex; justify-content: space-around; align-items: center;
}
.footer-nav button { background: none; color: #555; font-size: 0.9rem; }
.footer-nav button:hover { color: #000; }

/* 刷新按钮 */
.refresh-btn {
    position: fixed;
    bottom: 70px;
    right: 20px;
    padding: 8px 12px;
    background: #4a90e2;
    color: #fff;
    border: none;
    border-radius: 20px;
    box-shadow: 0 2px 6px rgba(0,0,0,0.2);
    cursor: pointer;
    font-size: 0.9rem;
    transition: background 0.2s;
}
.refresh-btn:hover {
    background: #357abd;
}

/* --- 🌙 深色模式 --- */
body.dark-mode {
  background: #121212;
  color: #eeeeee;
}
.dark-mode .header {
  background: #1e1e1e;
  box-shadow: 0 1px 4px rgba(255,255,255,0.1);
}
.dark-mode .footer-nav {
  background: #1e1e1e;
  border-top: 1px solid #333;
}
.dark-mode .btn-group button {
  background: #333;
  color: #eee;
  border-color: #555;
}
.dark-mode .btn-group button.active {
  background: #4a90e2;
  color: #fff;
  border-color: #4a90e2;
}
.dark-mode textarea,
.dark-mode input[type="text"],
.dark-mode input[type="number"],
.dark-mode select {
  background: #2c2c2c;
  color: #fff;
  border-color: #444;
}
.dark-mode button {
  background: #333333;
  color: #fff;
}
.dark-mode .refresh-btn {
  background: #555555;
}

/* 调整跳过按钮样式 */
#practice-skip-btn {
  background: #888;
}
#practice-skip-btn:hover {
  background: #666;
}

.modal {
  display: none;
  position: fixed;
  z-index: 9999;
  left: 0;
  top: 0;
  width: 100%;
  height: 100%;
  background-color: rgba(0,0,0,0.9);
  cursor: pointer;
}

.modal-container {
  position: relative;
  width: 100%;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
}

.close {
  position: fixed;
  top: 20px;
  right: 30px;
  color: #fff;
  font-size: 40px;
  font-weight: bold;
  z-index: 99999;
  cursor: pointer;
  transition: 0.3s;
}

.close:hover {
  color: #bbb;
  transform: scale(1.1);
}

/* 新增 ESC 键提示 */
.modal::after {
  position: fixed;
  bottom: 20px;
  left: 50%;
  transform: translateX(-50%);
  color: rgba(255,255,255,0.8);
  font-size: 14px;
}

#tutorial-modal {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(0,0,0,0.5);
  z-index: 9999;
  display: flex;
  align-items: center;
  justify-content: center;
}

#tutorial-modal .modal-content {
  background: white;
  border-radius: 10px;
  box-shadow: 0 2px 10px rgba(0,0,0,0.2);
  animation: modalSlide 0.3s ease-out;
}

@keyframes modalSlide {
  from { transform: translateY(-20px); opacity: 0; }
  to { transform: translateY(0); opacity: 1; }
}

.dark-mode #tutorial-modal .modal-content {
  background: #2d3748;
  color: white;
}

.header-buttons {
    display: flex;
    gap: 12px;
}

.header-buttons button {
    background: none;
    border: none;
    font-size: 1.4rem;
    padding: 8px;
    cursor: pointer;
    transition: transform 0.2s;
}

.header-buttons button:hover {
    transform: scale(1.1);
}

/* 深色模式适配 */
.dark-mode .header-buttons button {
    color: #e2e8f0;
}

/* 分类列表图片样式 */
#category-items .preview {
  max-width: 100px;
  max-height: 100px;
  margin-right: 12px;
  cursor: zoom-in;
  border: 1px solid #ddd;
  border-radius: 4px;
  object-fit: contain;
}

/* 练习图片样式 */
#practice-image {
  max-width: 100%;
  max-height: 300px;
  margin: 15px 0;
  border: 1px solid #ddd;
  border-radius: 4px;
  cursor: zoom-in;
}

/* 模态框图片优化 */
.modal-content {
  max-width: 90%;
  max-height: 90vh;
  padding: 20px;
  background: white;
  border-radius: 4px;
}

.custom-upload-btn {
  display: inline-block;
  padding: 10px 20px;
  background: linear-gradient(135deg, #667eea, #764ba2);
  color: white;
  font-size: 16px;
  font-weight: bold;
  border-radius: 30px;
  cursor: pointer;
  transition: background 0.3s ease;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.2);
  text-align: center;
}

.custom-upload-btn:hover {
  background: linear-gradient(135deg, #5a67d8, #6b46c1);
}

/* 分类选择 */
#category-select {
  margin-top: 12px;
  padding: 10px;
  border-radius: 8px;
  font-size: 15px;
  width: 100%;
  box-sizing: border-box;
}

/* 上传按钮和图片按钮通用样式 */
.upload-button {
  display: inline-block;
  padding: 12px 24px;
  font-size: 16px;
  font-weight: 600;
  color: white;
  background: linear-gradient(135deg, #42a5f5, #478ed1);
  border: none;
  border-radius: 30px;
  cursor: pointer;
  transition: all 0.3s ease;
  box-shadow: 0 4px 12px rgba(66, 165, 245, 0.4);
  text-align: center;
  user-select: none;
  margin-top: 18px;
}

.upload-button:hover {
  background: linear-gradient(135deg, #64b5f6, #5c9bd6);
  box-shadow: 0 6px 18px rgba(66, 165, 245, 0.5);
}

.upload-bot {
  display: inline-block;
  background: linear-gradient(to right, #6a11cb, #2575fc);
  color: #fff;
  padding: 10px 20px;
  font-size: 16px;
  font-weight: bold;
  border: none;
  border-radius: 12px;
  cursor: pointer;
  text-align: center;
  transition: all 0.3s ease;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
}

.upload-bot:hover {
  background: linear-gradient(to right, #5f0fff, #1e90ff);
  transform: scale(1.05);
  box-shadow: 0 6px 14px rgba(0, 0, 0, 0.2);
}

.upload-bot:active {
  transform: scale(0.97);
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
}