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

:root {
  --white: #ffffff;
  --gray-50: #f9f9f9;
  --gray-100: #f3f3f3;
  --gray-200: #e5e5e5;
  --gray-300: #d4d4d4;
  --gray-400: #a3a3a3;
  --gray-500: #737373;
  --gray-600: #525252;
  --gray-700: #404040;
  --gray-800: #262626;
  --black: #0a0a0a;
  --primary: #0a0a0a;
  --primary-hover: #262626;
  --error: #dc2626;
  --success: #16a34a;
  --radius-xl: 24px;
  --radius-lg: 16px;
  --radius-md: 12px;
  --radius-sm: 8px;
}

body {
  font-family: 'Inter', 'Noto Sans SC', -apple-system, sans-serif;
  background: var(--white);
  color: var(--gray-800);
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
}

/* 登录页面 */
.login-page {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 24px;
  overflow: hidden;
}

/* 背景装饰 */
.login-background {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  pointer-events: none;
  overflow: hidden;
}

.bg-shape {
  position: absolute;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--gray-100), var(--gray-200));
  opacity: 0.5;
}

.shape-1 {
  width: 400px;
  height: 400px;
  top: -200px;
  right: -100px;
  animation: float1 20s ease-in-out infinite;
}

.shape-2 {
  width: 300px;
  height: 300px;
  bottom: -150px;
  left: -100px;
  animation: float2 15s ease-in-out infinite;
  animation-delay: -5s;
}

.shape-3 {
  width: 200px;
  height: 200px;
  top: 50%;
  left: 50%;
  animation: float3 18s ease-in-out infinite;
  animation-delay: -10s;
}

@keyframes float1 {
  0%, 100% { transform: translate(0, 0) scale(1); }
  50% { transform: translate(-30px, 30px) scale(1.1); }
}

@keyframes float2 {
  0%, 100% { transform: translate(0, 0) scale(1); }
  50% { transform: translate(40px, -20px) scale(0.9); }
}

@keyframes float3 {
  0%, 100% { transform: translate(-50%, -50%) rotate(0deg); }
  50% { transform: translate(-50%, -50%) rotate(180deg); }
}

/* 登录容器 */
.login-container {
  position: relative;
  z-index: 1;
  width: 100%;
  max-width: 420px;
}

/* 登录卡片 */
.login-card {
  background: var(--white);
  border: 1px solid var(--gray-100);
  border-radius: var(--radius-xl);
  padding: 48px 40px;
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.08);
  animation: cardIn 0.6s ease-out;
}

@keyframes cardIn {
  from {
    opacity: 0;
    transform: translateY(30px) scale(0.95);
  }
  to {
    opacity: 1;
    transform: translateY(0) scale(1);
  }
}

/* 登录头部 */
.login-header {
  text-align: center;
  margin-bottom: 40px;
}

.login-icon {
  font-size: 56px;
  margin-bottom: 16px;
  animation: iconBounce 2s ease-in-out infinite;
}

@keyframes iconBounce {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-10px); }
}

.login-title {
  font-size: 28px;
  font-weight: 700;
  color: var(--gray-800);
  margin-bottom: 8px;
}

.login-subtitle {
  font-size: 14px;
  color: var(--gray-500);
  font-weight: 400;
}

/* 登录表单 */
.login-form {
  display: flex;
  flex-direction: column;
  gap: 24px;
}

.form-group {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.form-group label {
  font-size: 14px;
  font-weight: 500;
  color: var(--gray-700);
}

.form-group input {
  background: var(--gray-50);
  border: 1px solid var(--gray-200);
  border-radius: var(--radius-lg);
  padding: 14px 18px;
  font-size: 15px;
  font-family: inherit;
  color: var(--gray-800);
  outline: none;
  transition: all 0.2s ease;
}

.form-group input:focus {
  background: var(--white);
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(10, 10, 10, 0.1);
}

.form-group input::placeholder {
  color: var(--gray-400);
}

/* 表单选项 */
.form-options {
  display: flex;
  align-items: center;
}

.checkbox-wrapper {
  display: flex;
  align-items: center;
  gap: 8px;
  cursor: pointer;
  font-size: 14px;
  color: var(--gray-600);
  user-select: none;
}

.checkbox-wrapper input[type="checkbox"] {
  width: 18px;
  height: 18px;
  cursor: pointer;
  accent-color: var(--primary);
}

/* 登录按钮 */
.login-btn {
  background: var(--primary);
  color: var(--white);
  border: none;
  border-radius: var(--radius-lg);
  padding: 16px 32px;
  font-size: 16px;
  font-weight: 600;
  font-family: inherit;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  transition: all 0.3s ease;
}

.login-btn:hover {
  background: var(--primary-hover);
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.12);
}

.login-btn:active {
  transform: translateY(0);
}

.btn-icon {
  font-size: 18px;
  transition: transform 0.3s ease;
}

.login-btn:hover .btn-icon {
  transform: translateX(4px);
}

/* 登录消息 */
.login-message {
  min-height: 20px;
  text-align: center;
  font-size: 14px;
  opacity: 0;
  transition: opacity 0.3s ease;
}

.login-message.show {
  opacity: 1;
}

.login-message.error {
  color: var(--error);
}

.login-message.success {
  color: var(--success);
}

/* 登录底部 */
.login-footer {
  margin-top: 32px;
  text-align: center;
}

.back-link {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  color: var(--gray-500);
  text-decoration: none;
  font-size: 14px;
  font-weight: 500;
  transition: all 0.2s ease;
  padding: 8px 16px;
  border-radius: var(--radius-sm);
}

.back-link:hover {
  color: var(--gray-800);
  background: var(--gray-50);
}

.back-link span:first-child {
  transition: transform 0.2s ease;
}

.back-link:hover span:first-child {
  transform: translateX(-4px);
}

/* 响应式 */
@media (max-width: 480px) {
  .login-page {
    padding: 16px;
  }
  
  .login-card {
    padding: 36px 24px;
  }
  
  .login-title {
    font-size: 24px;
  }
  
  .login-icon {
    font-size: 48px;
  }
  
  .shape-1 {
    width: 200px;
    height: 200px;
  }
  
  .shape-2 {
    width: 150px;
    height: 150px;
  }
  
  .shape-3 {
    width: 100px;
    height: 100px;
  }
}

/* 黑夜模式 */
body.dark-mode {
  --white: #0a0a0a;
  --gray-50: #111111;
  --gray-100: #1a1a1a;
  --gray-200: #262626;
  --gray-300: #404040;
  --gray-400: #737373;
  --gray-500: #a3a3a3;
  --gray-600: #d4d4d4;
  --gray-700: #e5e5e5;
  --gray-800: #f3f3f3;
  --primary: #ffffff;
  --primary-hover: #f3f3f3;
}

body.dark-mode .login-card {
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.4);
}

body.dark-mode .bg-shape {
  background: linear-gradient(135deg, #1a1a1a, #262626);
}