/* 
 *
 * 视觉规格（与 Dart 对齐）：
 *   - Spacer → logo（120h）→ Spacer → Facebook 主按钮 → 链接 → Spacer → 法律
 *   - Facebook 主按钮：46px 白胶囊 + Facebook "f" 图标（#1877f2）
 *   - 链接：14px 黑色下划线居中
 */
.panel {
  display: flex;
  flex-direction: column;
  align-items: stretch;
  flex: 1 1 auto;
  width: 100%;
  min-height: 0;
}

.spacer {
  flex: 1 1 0;
  min-height: var(--spacing-lg);
}

.logo {
  display: block;
  height: var(--auth-logo-height);
  width: auto;
  max-width: 220px;
  margin: 0 auto;
  object-fit: contain;
}

.facebookButton {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-md);
  width: 100%;
  height: var(--auth-field-height);
  padding: 0 var(--spacing-lg);
  border: none;
  border-radius: var(--radius-xxxl);
  background: var(--color-auth-surface);
  color: var(--color-auth-text-primary);
  font-size: var(--font-size-md);
  font-weight: 600;
  cursor: pointer;
  margin-top: var(--spacing-md);
  box-shadow: 0 2px 6px rgba(0, 0, 0, 0.06);
  transition: filter 0.15s ease, transform 0.05s ease, opacity 0.15s ease;
}

.facebookButton:hover:not(:disabled) {
  filter: brightness(0.97);
}

.facebookButton:disabled {
  opacity: 0.6;
  cursor: not-allowed;
}

.facebookButton:not(:disabled):active {
  transform: scale(0.98);
}

.facebookIcon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 20px;
  height: 20px;
  flex: 0 0 auto;
}

.facebookLabel {
  flex: 0 0 auto;
  text-align: center;
}

.spinner {
  display: inline-block;
  width: 18px;
  height: 18px;
  border-width: 2px;
  border-style: solid;
  border-color: var(--color-facebook-blue) transparent transparent transparent;
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
  flex: 0 0 auto;
}

.linkButton {
  align-self: center;
  background: none;
  border: none;
  padding: var(--spacing-md) 0;
  font-size: var(--font-size-md);
  color: var(--color-auth-text-primary);
  text-decoration: underline;
  text-underline-offset: 3px;
  cursor: pointer;
  transition: opacity 0.15s ease;
}

.linkButton:hover {
  opacity: 0.8;
}

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