/* === 全局基础样式 === */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-family: 'Segoe UI', sans-serif;
}

body {
  height: 100vh;
  overflow: hidden;
  background: radial-gradient(circle at top left, #1b2735 0%, #090a0f 100%);
  color: #fff;
  display: flex;
  justify-content: center;
  align-items: center;
  flex-direction: column;
}

/* === 星空动态背景 === */
.background {
  position: absolute;
  width: 200%;
  height: 200%;
  background: black;
  background-size: cover;
  animation: moveStars 40s linear infinite;
  top: -50%;
  left: -50%;
  z-index: 0;
  opacity: 0.4;
}

@keyframes moveStars {
  from { transform: translate(0, 0) rotate(0deg); }
  to { transform: translate(50px, 50px) rotate(360deg); }
}

/* === 登录卡片 === */
.login-card {
  position: relative;
  z-index: 2;
  background: rgba(255, 255, 255, 0.1);
  backdrop-filter: blur(12px);
  padding: 40px 60px;
  border-radius: 20px;
  box-shadow: 0 0 30px rgba(0,0,0,0.4);
  text-align: center;
  transition: all 0.3s ease;
  animation: fadeInUp 1.2s ease forwards;
}

.login-card:hover {
  transform: translateY(-5px);
  box-shadow: 0 0 50px rgba(0, 170, 255, 0.5);
}

@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(40px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* === 标题区 === */
.title {
  font-size: 2.5rem;
  font-weight: 600;
  background: linear-gradient(90deg, #00c6ff, #0072ff);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  margin-bottom: 10px;
}

.subtitle {
  color: #ccc;
  margin-bottom: 25px;
}

/* === 输入框 === */
.input-group {
  margin-bottom: 20px;
}

.input-group input {
  width: 100%;
  padding: 12px;
  border: none;
  border-radius: 10px;
  background: rgba(255,255,255,0.15);
  color: #fff;
  font-size: 15px;
  outline: none;
  transition: 0.3s;
}

.input-group input:focus {
  background: rgba(255,255,255,0.25);
  box-shadow: 0 0 10px #00b7ff;
}

/* === 按钮 === */
.login-btn {
  width: 100%;
  padding: 12px;
  font-size: 16px;
  background: linear-gradient(90deg, #00c6ff, #0072ff);
  border: none;
  border-radius: 10px;
  color: #fff;
  cursor: pointer;
  transition: all 0.3s ease;
}

.login-btn:hover {
  transform: scale(1.05);
  background: linear-gradient(90deg, #0072ff, #00c6ff);
}

/* === 文字提示 === */
.tips {
  margin-top: 15px;
  font-size: 14px;
  color: #ccc;
}

.tips a {
  color: #00b7ff;
  text-decoration: none;
  transition: 0.3s;
}

.tips a:hover {
  color: #fff;
}

/* === 页脚 === */
footer {
  position: absolute;
  bottom: 15px;
  font-size: 12px;
  color: #888;
  text-align: center;
  z-index: 2;
}