* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  min-height: 100vh;
  display: flex;
  justify-content: center;
  align-items: center;
  overflow: hidden;
}

/* 背景動畫效果 */
body::before {
  content: '';
  position: absolute;
  top: -50%;
  left: -50%;
  width: 200%;
  height: 200%;
  background: radial-gradient(circle, rgba(255,255,255,0.1) 1px, transparent 1px);
  background-size: 50px 50px;
  animation: moveBackground 20s linear infinite;
}

@keyframes moveBackground {
  0% { transform: translate(0, 0); }
  100% { transform: translate(50px, 50px); }
}

.login-container {
  position: relative;
  z-index: 1;
  width: 100%;
  max-width: 450px;
  padding: 20px;
}

.login-box {
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(10px);
  border-radius: 20px;
  padding: 40px;
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
  animation: slideIn 0.5s ease-out;
}

@keyframes slideIn {
  from {
    opacity: 0;
    transform: translateY(-30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* Logo 區域 */
.logo {
  text-align: center;
  margin-bottom: 30px;
}

.logo-icon {
  font-size: 64px;
  margin-bottom: 10px;
  animation: pulse 2s ease-in-out infinite;
}

@keyframes pulse {
  0%, 100% { transform: scale(1); }
  50% { transform: scale(1.1); }
}

.game-title {
  font-size: 32px;
  font-weight: bold;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin: 0;
}

/* 歡迎文字 */
.welcome-title {
  text-align: center;
  font-size: 24px;
  color: #333;
  margin-bottom: 10px;
}

.welcome-subtitle {
  text-align: center;
  font-size: 14px;
  color: #666;
  margin-bottom: 30px;
}

/* 登入選項 */
.login-options {
  display: flex;
  flex-direction: column;
  gap: 15px;
}

.login-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  padding: 15px 20px;
  border: none;
  border-radius: 12px;
  font-size: 16px;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.3s ease;
  position: relative;
  overflow: hidden;
}

.login-btn::before {
  content: '';
  position: absolute;
  top: 50%;
  left: 50%;
  width: 0;
  height: 0;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.3);
  transform: translate(-50%, -50%);
  transition: width 0.6s, height 0.6s;
}

.login-btn:hover::before {
  width: 300px;
  height: 300px;
}

.btn-icon {
  width: 24px;
  height: 24px;
  position: relative;
  z-index: 1;
}

/* Google 登入按鈕 */
.google-btn {
  background: white;
  color: #333;
  border: 2px solid #e0e0e0;
}

.google-btn:hover {
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
  transform: translateY(-2px);
}

/* App 登入按鈕 */
.app-btn {
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  color: white;
}

.app-btn:hover {
  box-shadow: 0 6px 20px rgba(102, 126, 234, 0.4);
  transform: translateY(-2px);
}

/* 分隔線 */
.divider {
  display: flex;
  align-items: center;
  text-align: center;
  color: #999;
  margin: 10px 0;
}

.divider::before,
.divider::after {
  content: '';
  flex: 1;
  border-bottom: 1px solid #ddd;
}

.divider span {
  padding: 0 15px;
  font-size: 14px;
}

/* 快速登入提示 */
.quick-login {
  text-align: center;
  margin-top: 20px;
}

.hint-text {
  font-size: 14px;
  color: #666;
}

.hint-text a,
.register-link-text {
  color: #667eea;
  text-decoration: none;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.3s;
}

.hint-text a:hover,
.register-link-text:hover {
  text-decoration: underline;
  color: #764ba2;
}

/* Modal 樣式 */
.modal {
  display: none;
  position: fixed;
  z-index: 1000;
  left: 0;
  top: 0;
  width: 100%;
  height: 100%;
  background: rgba(0, 0, 0, 0.6);
  backdrop-filter: blur(5px);
  animation: fadeIn 0.3s ease;
}

.modal.show {
  display: flex;
  justify-content: center;
  align-items: center;
}

@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

.modal-content {
  background: white;
  border-radius: 16px;
  width: 90%;
  max-width: 400px;
  box-shadow: 0 10px 40px rgba(0, 0, 0, 0.3);
  animation: modalSlideIn 0.3s ease;
}

@keyframes modalSlideIn {
  from {
    opacity: 0;
    transform: translateY(-50px) scale(0.9);
  }
  to {
    opacity: 1;
    transform: translateY(0) scale(1);
  }
}

.modal-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 20px 25px;
  border-bottom: 1px solid #eee;
}

.modal-header h3 {
  margin: 0;
  font-size: 20px;
  color: #333;
}

.close-btn {
  background: none;
  border: none;
  font-size: 28px;
  color: #999;
  cursor: pointer;
  line-height: 1;
  transition: color 0.3s;
}

.close-btn:hover {
  color: #333;
}

.modal-body {
  padding: 25px;
}

/* 表單樣式 */
.form-group {
  margin-bottom: 20px;
}

.form-group label {
  display: block;
  margin-bottom: 8px;
  font-size: 14px;
  font-weight: 600;
  color: #333;
}

.form-group input {
  width: 100%;
  padding: 12px 15px;
  border: 2px solid #e0e0e0;
  border-radius: 8px;
  font-size: 14px;
  transition: border-color 0.3s;
}

.form-group input:focus {
  outline: none;
  border-color: #667eea;
}

.form-options {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 20px;
  font-size: 14px;
}

.checkbox-label {
  display: flex;
  align-items: center;
  gap: 6px;
  cursor: pointer;
  color: #666;
}

.checkbox-label input {
  cursor: pointer;
}

.forgot-password {
  color: #667eea;
  text-decoration: none;
  font-weight: 600;
}

.forgot-password:hover {
  text-decoration: underline;
}

.submit-btn {
  width: 100%;
  padding: 14px;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  color: white;
  border: none;
  border-radius: 8px;
  font-size: 16px;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.3s;
}

.submit-btn:hover {
  box-shadow: 0 4px 12px rgba(102, 126, 234, 0.4);
  transform: translateY(-2px);
}

.register-link {
  text-align: center;
  margin-top: 20px;
  font-size: 14px;
  color: #666;
}

.register-link a {
  color: #667eea;
  text-decoration: none;
  font-weight: 600;
}

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

/* 載入動畫 */
.loading-overlay {
  display: none;
  position: fixed;
  z-index: 2000;
  left: 0;
  top: 0;
  width: 100%;
  height: 100%;
  background: rgba(0, 0, 0, 0.8);
  justify-content: center;
  align-items: center;
  flex-direction: column;
}

.loading-overlay.show {
  display: flex;
}

.loading-spinner {
  width: 50px;
  height: 50px;
  border: 4px solid rgba(255, 255, 255, 0.3);
  border-top-color: white;
  border-radius: 50%;
  animation: spin 1s linear infinite;
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

.loading-overlay p {
  color: white;
  margin-top: 20px;
  font-size: 16px;
}

/* 響應式設計 */
@media (max-width: 480px) {
  .login-box {
    padding: 30px 20px;
  }

  .game-title {
    font-size: 28px;
  }

  .welcome-title {
    font-size: 20px;
  }

  .login-btn {
    font-size: 14px;
    padding: 12px 16px;
  }
}