/**
 * AKSRT Theme Background System
 *
 * 全局背景图、夜间背景图、页面背景色/背景图。
 * 所有选择器均带 aksrt- 命名空间。
 */

/* ========== 全局背景 ========== */
.aksrt-bg-body {
  background-color: var(--aksrt-bg-color, transparent);
  background-image: var(--aksrt-bg-image, none);
  background-size: var(--aksrt-bg-size, cover);
  background-position: var(--aksrt-bg-position, center center);
  background-repeat: var(--aksrt-bg-repeat, no-repeat);
  background-attachment: var(--aksrt-bg-attachment, fixed);
}

/* ========== 夜间模式背景 ========== */
.aksrt-bg-dark {
  background-color: var(--aksrt-bg-dark-color, transparent);
  background-image: var(--aksrt-bg-dark-image, none);
}

/* ========== 页面级背景 ========== */
.aksrt-bg-page {
  background-color: var(--aksrt-page-bg-color, transparent);
  background-image: var(--aksrt-page-bg-image, none);
  background-size: cover;
  background-position: center center;
  background-repeat: no-repeat;
}

/* ========== 模块级背景 ========== */
.aksrt-bg-module {
  background-color: var(--aksrt-module-bg-color, transparent);
  background-image: var(--aksrt-module-bg-image, none);
  background-size: cover;
  background-position: center center;
  background-repeat: no-repeat;
}

/* ========== 背景遮罩层（提升文字可读性）========== */
.aksrt-bg-overlay {
  position: relative;
}

.aksrt-bg-overlay::before {
  content: '';
  position: absolute;
  inset: 0;
  background: var(--aksrt-bg-overlay-color, rgba(0, 0, 0, 0.3));
  pointer-events: none;
  z-index: 0;
}

.aksrt-bg-overlay > * {
  position: relative;
  z-index: 1;
}

/* ========== 暗色模式自动切换 ========== */
@media (prefers-color-scheme: dark) {
  :root:not(.aksrt-light-mode) .aksrt-bg-body {
    background-color: var(--aksrt-bg-dark-color, var(--aksrt-bg-color, transparent));
    background-image: var(--aksrt-bg-dark-image, var(--aksrt-bg-image, none));
  }
}

html.aksrt-dark-mode .aksrt-bg-body {
  background-color: var(--aksrt-bg-dark-color, var(--aksrt-bg-color, transparent));
  background-image: var(--aksrt-bg-dark-image, var(--aksrt-bg-image, none));
}