:root {
  --slide-background: #f7fbfc;
  --slide-stage-background: #e5eef1;
  --slide-surface-raised: #ffffff;
  --slide-surface-muted: #edf5f6;
  --slide-surface-translucent: rgba(255, 255, 255, .90);
  --slide-surface-translucent-soft: rgba(255, 255, 255, .74);
  --slide-ink: #102a35;
  --slide-ink-soft: #45616c;
  --slide-primary: #0d6475;
  --slide-primary-soft: #dff0f2;
  --slide-auxiliary: #c26432;
  --slide-auxiliary-soft: #faebdf;
  --slide-line: #94adb5;
  --slide-line-soft: #c5d6da;
  --slide-breadcrumb-muted: #748c95;
  --slide-progress-ink: #617983;
  --slide-footer-ink: #506b75;
  --slide-progress-track: #cfdee2;
  --slide-cover-description-ink: #35545f;
  --slide-cover-meta-ink: #617983;
  --slide-on-primary: #ffffff;
  --slide-card-shadow: rgba(16, 42, 53, .16);
  --slide-navigation-shadow: rgba(13, 100, 117, .18);
  --slide-code-active-line: #f1cfba;
  --slide-code-ink: #102a35;
  --slide-code-meta-ink: #617983;
  --slide-code-keyword: #0d6475;
  --slide-code-literal: #c26432;
  --slide-overlay-background: rgba(16, 42, 53, .82);
  --slide-overlay-line: rgba(255, 255, 255, .72);
  --slide-overlay-shadow: rgba(0, 0, 0, .36);
  --slide-component-radius: 6px;
  --slide-table-header-background: var(--slide-primary-soft);
  --slide-table-header-ink: var(--slide-primary);
  --slide-title-font: "Course Source Han Sans", "Source Han Sans SC", "Noto Sans CJK SC", "PingFang SC", "Microsoft YaHei", system-ui, sans-serif;
  --slide-body-font: "Course Source Han Sans", "Source Han Sans SC", "Noto Sans CJK SC", "PingFang SC", "Microsoft YaHei", system-ui, sans-serif;
}

/* Course-level surface treatment: light object frames with restrained corners. */
.content-card,
.reading-panel,
.media-block {
  border-width: 1px;
}

.relation-term {
  border-top-width: 2px;
}