/* ===== 极光渐变配色（复用主站体系） ===== */
:root {
  --bg-deep: #0a0a1a;
  --bg-card: rgba(255, 255, 255, 0.03);
  --bg-input: rgba(255, 255, 255, 0.05);
  --text-primary: #e8e8f0;
  --text-secondary: rgba(255, 255, 255, 0.5);
  --gradient-1: #667eea;
  --gradient-2: #764ba2;
  --gradient-3: #f64f59;
  --gradient-4: #12c2e9;
  --glow-purple: rgba(118, 75, 162, 0.4);
  --glow-blue: rgba(102, 126, 234, 0.4);
  --glow-pink: rgba(246, 79, 89, 0.3);
  --border-color: rgba(255, 255, 255, 0.08);
  --radius: 20px;
  --radius-sm: 12px;
  --transition: 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}

:root[data-theme='light'] {
  --bg-deep: #f3f6ff;
  --bg-card: rgba(255, 255, 255, 0.72);
  --bg-input: rgba(102, 126, 234, 0.1);
  --text-primary: #1e2433;
  --text-secondary: rgba(30, 36, 51, 0.62);
  --glow-purple: rgba(118, 75, 162, 0.18);
  --glow-blue: rgba(102, 126, 234, 0.18);
  --glow-pink: rgba(246, 79, 89, 0.14);
  --border-color: rgba(103, 122, 170, 0.24);
}

/* ===== 基础重置 ===== */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

/* ===== 背景与主体 ===== */
body {
  font-family: -apple-system, BlinkMacSystemFont, 'SF Pro Display', 'Segoe UI', Roboto, sans-serif;
  background: var(--bg-deep);
  color: var(--text-primary);
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  overflow: hidden;
}

/* 极光背景 */
body::before {
  content: '';
  position: fixed;
  top: -50%;
  left: -50%;
  width: 200%;
  height: 200%;
  background:
    radial-gradient(ellipse 80% 50% at 20% 40%, var(--glow-purple), transparent 50%),
    radial-gradient(ellipse 60% 40% at 80% 20%, var(--glow-blue), transparent 50%),
    radial-gradient(ellipse 50% 30% at 60% 80%, var(--glow-pink), transparent 50%);
  animation: aurora 20s ease-in-out infinite alternate;
  pointer-events: none;
  z-index: -1;
}

:root[data-theme='light'] body::before {
  opacity: 0;
}

@keyframes aurora {
  0% { transform: translate(0, 0) rotate(0deg); }
  50% { transform: translate(-5%, 5%) rotate(3deg); }
  100% { transform: translate(5%, -5%) rotate(-3deg); }
}

/* 星星点点 */
body::after {
  content: '';
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background-image:
    radial-gradient(2px 2px at 20px 30px, rgba(255,255,255,0.3), transparent),
    radial-gradient(2px 2px at 40px 70px, rgba(255,255,255,0.2), transparent),
    radial-gradient(1px 1px at 90px 40px, rgba(255,255,255,0.4), transparent),
    radial-gradient(2px 2px at 130px 80px, rgba(255,255,255,0.2), transparent),
    radial-gradient(1px 1px at 160px 120px, rgba(255,255,255,0.3), transparent);
  background-size: 200px 200px;
  pointer-events: none;
  z-index: -1;
  opacity: 0.6;
}

:root[data-theme='light'] body::after {
  opacity: 0;
}

/* ===== 登录卡片 ===== */
.auth-card {
  background: var(--bg-card);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border: 1px solid var(--border-color);
  border-radius: 24px;
  padding: 48px;
  text-align: center;
  max-width: 380px;
  width: 90%;
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
  position: relative;
}

/* 渐变边框 */
.auth-card::before {
  content: '';
  position: absolute;
  inset: 0;
  border-radius: 24px;
  padding: 1px;
  background: linear-gradient(135deg,
    rgba(102, 126, 234, 0.3),
    rgba(118, 75, 162, 0.1),
    rgba(246, 79, 89, 0.3));
  -webkit-mask:
    linear-gradient(#fff 0 0) content-box,
    linear-gradient(#fff 0 0);
  -webkit-mask-composite: xor;
  mask-composite: exclude;
  opacity: 0;
  transition: opacity var(--transition);
  pointer-events: none;
}

.auth-card:hover::before {
  opacity: 1;
}

.auth-icon {
  font-size: 48px;
  margin-bottom: 20px;
  animation: float 6s ease-in-out infinite;
}

@keyframes float {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-8px); }
}

.auth-title {
  font-size: 1.5rem;
  font-weight: 700;
  margin-bottom: 8px;
  background: linear-gradient(135deg, var(--gradient-4), var(--gradient-1), var(--gradient-2));
  background-size: 200% 200%;
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  animation: gradient-shift 8s ease infinite;
}

@keyframes gradient-shift {
  0%, 100% { background-position: 0% 50%; }
  50% { background-position: 100% 50%; }
}

.auth-subtitle {
  color: var(--text-secondary);
  font-size: 14px;
  margin-bottom: 32px;
}

.auth-form {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.auth-input {
  width: 100%;
  padding: 16px 20px;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  background: var(--bg-input);
  color: var(--text-primary);
  font-size: 16px;
  text-align: center;
  letter-spacing: 4px;
  transition: all 0.3s ease;
}

.auth-input:focus {
  outline: none;
  border-color: var(--gradient-1);
  box-shadow: 0 0 20px var(--glow-blue);
}

.auth-input::placeholder {
  letter-spacing: normal;
  color: var(--text-secondary);
  opacity: 0.6;
}

.auth-input.shake {
  animation: shake 0.5s ease;
  border-color: var(--gradient-3);
}

@keyframes shake {
  0%, 100% { transform: translateX(0); }
  20%, 60% { transform: translateX(-8px); }
  40%, 80% { transform: translateX(8px); }
}

.auth-btn {
  width: 100%;
  padding: 16px;
  border: none;
  border-radius: var(--radius-sm);
  background: linear-gradient(135deg, var(--gradient-1), var(--gradient-2));
  color: #fff;
  font-size: 16px;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.3s ease;
  box-shadow: 0 4px 15px var(--glow-purple);
}

.auth-btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 25px var(--glow-purple);
}

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

.auth-btn:disabled {
  opacity: 0.6;
  cursor: not-allowed;
  transform: none;
}

.auth-error {
  color: var(--gradient-3);
  font-size: 13px;
  min-height: 20px;
  margin-top: 4px;
}

/* ===== 响应式 ===== */
@media (max-width: 640px) {
  .auth-card {
    padding: 36px 28px;
  }

  .auth-icon {
    font-size: 40px;
  }

  .auth-title {
    font-size: 1.3rem;
  }
}

/* ===== 减少动画 ===== */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
  }
}