/* login.css — 简洁科技风，精致细节 */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: 'Inter', system-ui, -apple-system, 'Segoe UI', Roboto, 'Helvetica Neue', sans-serif;
  background: radial-gradient(circle at 30% 10%, #0b1120, #04070f);
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 1.5rem;
  position: relative;
}

/* 微动感光晕，增加科技层次 (不浮夸) */
body::before {
  content: '';
  position: fixed;
  inset: 0;
  background: radial-gradient(ellipse at 70% 40%, rgba(0, 212, 255, 0.08), transparent 70%);
  pointer-events: none;
  z-index: 0;
}

.login-container {
  width: 100%;
  max-width: 400px;
  position: relative;
  z-index: 2;
}

/* 卡片：半玻璃质感 + 细腻描边 */
.login-card {
  background: rgba(15, 23, 42, 0.75);
  backdrop-filter: blur(8px);
  border-radius: 32px;
  padding: 2rem 1.8rem 2rem 1.8rem;
  border: 1px solid rgba(66, 153, 225, 0.25);
  box-shadow: 0 20px 35px -12px rgba(0, 0, 0, 0.4), 0 0 0 0.5px rgba(0, 212, 255, 0.1) inset;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.login-card:hover {
  box-shadow: 0 24px 42px -16px rgba(0, 160, 255, 0.2), 0 0 0 1px rgba(0, 180, 255, 0.2) inset;
}

/* 头部区域 — 清晰简练 */
.login-header {
  text-align: center;
  margin-bottom: 2rem;
  position: relative;
}

.logo-marker {
  width: 42px;
  height: 42px;
  background: linear-gradient(135deg, #2b6ef0, #00c3ff);
  border-radius: 14px;
  margin: 0 auto 1rem auto;
  box-shadow: 0 8px 20px -6px rgba(0, 160, 255, 0.4);
  position: relative;
}

.logo-marker::after {
  content: 'BK';
  font-weight: 700;
  font-size: 24px;
  color: white;
  display: flex;
  align-items: center;
  justify-content: center;
  height: 100%;
  letter-spacing: 0;
}

.login-header h1 {
  font-size: 1.9rem;
  font-weight: 600;
  letter-spacing: -0.3px;
  background: linear-gradient(120deg, #f0f5ff, #b9e2ff);
  background-clip: text;
  -webkit-background-clip: text;
  color: transparent;
  margin-bottom: 0.4rem;
}

.login-header p {
  color: #8d9ec0;
  font-size: 0.85rem;
  font-weight: 450;
  letter-spacing: 0.2px;
  border-top: 1px dashed rgba(72, 187, 255, 0.3);
  display: inline-block;
  padding-top: 6px;
}

/* 表单组 */
.form-group {
  margin-bottom: 1.5rem;
}

.form-group label {
  display: block;
  font-size: 0.8rem;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  color: #a5bbdf;
  margin-bottom: 0.5rem;
}

/* 输入框容器 + 科技细线效果 */
.input-wrapper {
  position: relative;
  width: 100%;
}

.input-wrapper input {
  width: 100%;
  padding: 0.85rem 1rem;
  background: rgba(5, 12, 24, 0.7);
  border: 1px solid rgba(56, 128, 255, 0.35);
  border-radius: 20px;
  font-size: 0.95rem;
  font-weight: 450;
  color: #eef4ff;
  transition: all 0.2s ease;
  outline: none;
  font-family: 'Inter', monospace;
}

.input-wrapper input:focus {
  border-color: #3b82f6;
  box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.2), 0 0 0 1px #3b82f6 inset;
  background: rgba(8, 18, 34, 0.9);
}

.input-wrapper input::placeholder {
  color: #4f607c;
  font-weight: 400;
  font-size: 0.85rem;
}

/* 科技风按钮 */
.btn-login {
  width: 100%;
  background: linear-gradient(95deg, #1e2b4f, #0f1a30);
  border: 1px solid rgba(0, 180, 255, 0.5);
  padding: 0.85rem 0;
  border-radius: 40px;
  font-weight: 600;
  font-size: 0.95rem;
  color: #eef5ff;
  letter-spacing: 0.5px;
  cursor: pointer;
  transition: 0.2s;
  margin-top: 0.8rem;
  backdrop-filter: blur(4px);
  box-shadow: 0 2px 5px rgba(0, 0, 0, 0.2);
}

.btn-login:hover {
  background: linear-gradient(95deg, #26406e, #14233f);
  border-color: #3b82f6;
  box-shadow: 0 6px 14px rgba(0, 120, 255, 0.2);
  transform: translateY(-1px);
}

.btn-login:active {
  transform: translateY(1px);
}

/* 错误提示轻量化 */
.error-message {
  color: #ff8a7a;
  font-size: 0.75rem;
  text-align: center;
  margin-top: 1.2rem;
  min-height: 36px;
  transition: opacity 0.2s;
  background: rgba(255, 80, 80, 0.05);
  padding: 0.5rem;
  border-radius: 40px;
  letter-spacing: 0.2px;
  font-weight: 450;
}

/* 底部极简辅助 */
.login-footer {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  margin-top: 2rem;
  font-size: 0.7rem;
  color: #5f729b;
  border-top: 1px solid rgba(72, 187, 255, 0.2);
  padding-top: 1rem;
}

.login-footer a {
  color: #79b8ff;
  text-decoration: none;
  transition: color 0.2s;
}

.login-footer a:hover {
  color: #aac9ff;
  text-decoration: underline;
}

.dot {
  font-size: 0.5rem;
  opacity: 0.6;
}

/* 响应式微调 */
@media (max-width: 480px) {
  .login-card {
    padding: 1.6rem 1.2rem;
  }
  .login-header h1 {
    font-size: 1.7rem;
  }
  .btn-login {
    padding: 0.75rem 0;
  }
}

/* 平滑焦点环 — 提升可访问性 */
input:focus-visible {
  outline: none;
}