:root {
  --dynamic-color-primary: #4285F4;
  --dynamic-color-secondary: #03DAC6;
  --dynamic-color-background: #F5F5F5;
  --dynamic-color-surface: #FFFFFF;
  --dynamic-color-on-primary: #FFFFFF;
  --dynamic-color-on-secondary: #000000;
  --dynamic-color-on-background: #000000;
  --dynamic-color-on-surface: #000000;
  --dynamic-color-danger: #FF0000;
  --card-color: #4285F4;
}

/* 深色模式变量 */
[data-theme="dark"] {
  --dynamic-color-primary: #4f8eff;
  --dynamic-color-secondary: #00ddc1;
  --dynamic-color-background: #121212;
  --dynamic-color-surface: #1e1e1e;
  --dynamic-color-on-primary: #FFFFFF;
  --dynamic-color-on-secondary: #000000;
  --dynamic-color-on-background: #FFFFFF;
  --dynamic-color-on-surface: #FFFFFF;
  --dynamic-color-danger: #FF5252;
}

body {
  margin: 0;
  font-family: 'Google Sans', sans-serif;
  font-size: 14px;
  background-color: var(--dynamic-color-background);
  color: var(--dynamic-color-on-background);
  -webkit-text-size-adjust: 100%;
  transition: background-color 0.3s ease, color 0.3s ease;
}

/* 顶部栏 */
header {
  background-color: var(--dynamic-color-primary);
  color: var(--dynamic-color-on-primary);
  padding: 12px;
  font-size: 18px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  position: relative;
}
.header-title {
  flex-grow: 1;
  text-align: center;
  margin: 0;
  position: absolute;
  left: 50%;
  transform: translateX(-50%);
  font-size: 18px;
}
header button {
  background-color: var(--dynamic-color-secondary);
  color: var(--dynamic-color-on-secondary);
  border: none;
  border-radius: 50%;
  width: 36px;
  height: 36px;
  font-size: 18px;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 1001;

  -webkit-appearance: button;
  appearance: button;
}

/* 左侧导航抽屉 */
.nav-drawer {
  display: none;
  position: fixed;
  top: 0;
  left: 0;
  width: 250px;
  height: 100%;
  background-color: var(--dynamic-color-surface);
  box-shadow: 2px 0 5px rgba(0, 0, 0, 0.1);
  padding-top: 60px;
  transition: transform 0.3s ease-in-out;
  z-index: 1000;
}
.nav-drawer.open {
  display: block;
}
.nav-drawer ul {
  list-style-type: none;
  padding: 0;
  margin: 0;
}
.nav-drawer ul li {
  padding: 16px;
  border-bottom: 1px solid var(--dynamic-color-background);
  cursor: pointer;
}
.nav-drawer ul li:hover {
  background-color: var(--dynamic-color-background);
}
.nav-drawer .close-button {
  position: absolute;
  top: 10px;
  right: 10px;
  background-color: var(--dynamic-color-secondary);
  color: var(--dynamic-color-on-secondary);
  border: none;
  border-radius: 50%;
  width: 30px;
  height: 30px;
  font-size: 14px;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;

  -webkit-appearance: button;
  appearance: button;
}

/* 主体内容 */
main {
  padding: 12px;
  padding-bottom: 60px; /* 给底部留点空隙，便于手机端查看 */
}
.page-content {
  display: none;
}
.page-content.active {
  display: block;
}

/* 卡片样式 */
.card {
  background-color: var(--dynamic-color-surface);
  color: var(--dynamic-color-on-surface);
  border-radius: 16px;
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
  margin-bottom: 16px;
  padding: 12px;
  position: relative;
  font-size: 14px;
}
.card h2 {
  margin: 0;
  font-size: 18px;
  display: inline-block;
}

/* 表单组件 */
.form-group {
  margin-bottom: 16px;
}
.form-group label {
  display: block;
  margin-bottom: 8px;
  font-weight: 500;
}
.text-field {
  width: calc(100% - 16px);
  padding: 8px;
  border: 1px solid var(--dynamic-color-secondary);
  border-radius: 8px;
  font-size: 14px;
  outline: none;
  display: block;
}

/* 信用卡预览区域 */
.credit-card-preview {
  margin-top: 20px;
  margin-bottom: 30px;
  text-align: center;
}
.credit-card-container {
  width: 320px;
  height: 200px;
  margin: 0 auto 20px;
  position: relative;
  perspective: 1000px;
}
.credit-card {
  width: 100%;
  height: 100%;
  position: absolute;
  transform-style: preserve-3d;
  transition: transform 0.8s;
  border-radius: 16px;
  box-shadow: 0 4px 8px rgba(0, 0, 0, 0.2);
  padding: 20px;
  box-sizing: border-box;
  color: white;
  font-family: 'Roboto', sans-serif;
}
.credit-card.front {
  background: var(--card-color);
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  backface-visibility: hidden;
}
.credit-card.back {
  background: var(--card-color);
  transform: rotateY(180deg);
  backface-visibility: hidden;
}
.credit-card-container.flipped .credit-card.front {
  transform: rotateY(180deg);
}
.credit-card-container.flipped .credit-card.back {
  transform: rotateY(0deg);
}

/* 信用卡正面元素 */
.card-chip {
  width: 50px;
  height: 40px;
  background: linear-gradient(135deg, #bdbdbd 0%, #e0e0e0 50%, #bdbdbd 100%);
  border-radius: 8px;
  margin-bottom: 20px;
  position: relative;
}
.card-chip::before {
  content: '';
  position: absolute;
  top: 10px;
  left: 10px;
  right: 10px;
  bottom: 10px;
  background: linear-gradient(135deg, #d4a100 0%, #e9c74e 50%, #d4a100 100%);
  border-radius: 4px;
}
.card-issuer {
  position: absolute;
  top: 20px;
  right: 20px;
  height: 40px;
  width: 60px;
  background-size: contain;
  background-repeat: no-repeat;
  background-position: center;
}
.card-number {
  font-size: 20px;
  letter-spacing: 2px;
  margin-bottom: 20px;
  text-align: center;
}
.card-info {
  display: flex;
  justify-content: space-between;
}
.card-holder, .card-expiry {
  font-size: 12px;
}
.card-holder label, .card-expiry label {
  display: block;
  text-transform: uppercase;
  font-size: 10px;
  margin-bottom: 4px;
  opacity: 0.8;
}

/* 信用卡背面元素 */
.card-magnetic-strip {
  width: 100%;
  height: 40px;
  background-color: #2a2a2a;
  margin: 20px 0;
}
.card-signature {
  margin-top: 20px;
  display: flex;
  align-items: center;
}
.signature-strip {
  flex-grow: 1;
  height: 40px;
  background-color: white;
  margin-right: 20px;
  border-radius: 4px;
  overflow: hidden;
  position: relative;
}
#displaySignature {
  font-family: 'Brush Script MT', cursive;
  color: #555;
  font-size: 24px;
  position: absolute;
  top: 50%;
  left: 10px;
  transform: translateY(-50%);
}
.cvv {
  text-align: right;
}
.cvv label {
  display: block;
  font-size: 10px;
  margin-bottom: 4px;
  opacity: 0.8;
}
.card-issuer-back {
  position: absolute;
  bottom: 20px;
  right: 20px;
  height: 30px;
  width: 50px;
  background-size: contain;
  background-repeat: no-repeat;
  background-position: center;
}

/* 按钮样式 */
.button {
  background-color: var(--dynamic-color-secondary);
  color: var(--dynamic-color-on-secondary);
  border: none;
  border-radius: 16px;
  padding: 10px 20px;
  cursor: pointer;
  font-size: 14px;
  margin-top: 20px;
  transition: background-color 0.3s;
  -webkit-appearance: button;
  appearance: button;
}
.button:hover {
  background-color: var(--dynamic-color-primary);
  color: var(--dynamic-color-on-primary);
}

/* 卡片详情区域 */
.card-details {
  margin-top: 20px;
  border-top: 1px solid #eee;
  padding-top: 20px;
}
.detail-item {
  margin-bottom: 10px;
  display: flex;
  align-items: center;
}
.detail-item label {
  font-weight: bold;
  margin-right: 10px;
  min-width: 120px;
}
.detail-item span {
  flex-grow: 1;
  margin-right: 10px;
}

/* 复制按钮 */
.copy-button {
  background-color: var(--dynamic-color-secondary);
  color: var(--dynamic-color-on-secondary);
  border: none;
  border-radius: 4px;
  padding: 4px 8px;
  font-size: 12px;
  cursor: pointer;
  transition: background-color 0.2s;
}
.copy-button:hover {
  background-color: var(--dynamic-color-primary);
  color: var(--dynamic-color-on-primary);
}
.copy-button.copied {
  background-color: #4CAF50;
  color: white;
}

/* 卡片按钮区域 */
.card-buttons {
  display: flex;
  justify-content: center;
  gap: 10px;
}

/* 保存成功提示 */
.toast-message {
  position: fixed;
  bottom: 20px;
  left: 50%;
  transform: translateX(-50%);
  background-color: rgba(0, 0, 0, 0.7);
  color: white;
  padding: 10px 20px;
  border-radius: 4px;
  z-index: 2000;
  opacity: 0;
  transition: opacity 0.3s;
}
.toast-message.show {
  opacity: 1;
}

/* 卡片标题和关闭按钮 */
.card-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 8px;
}

/* 折叠内容区域 */
.collapse-content {
  margin-top: 16px;
}
.collapse-content.hidden {
  display: none;
}

/* 关于/教程等页面样式 */
.about-info {
  margin-top: 12px;
  line-height: 1.6;
}

/* 深色模式切换按钮 */
.dark-mode-toggle {
  background-color: transparent;
  color: var(--dynamic-color-on-primary);
  border: none;
  border-radius: 50%;
  width: 36px;
  height: 36px;
  font-size: 20px;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 1001;
  padding: 0;
  
  -webkit-appearance: button;
  appearance: button;
}

/* 响应式：大于768px时，卡片居中显示 */
@media (min-width: 768px) {
  .card {
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
  }
}