/* ── 深色模式变量覆盖 ── */
[data-theme="dark"] {
  --body-background: #2e3440;
  --body-font-color: #eceff4;
  --color-link: #81a1c1;
  --color-visited-link: #81a1c1;
  --icon-filter: brightness(0) invert(1);
  --gray-100: #3b4252;
  --gray-200: #434c5e;
  --gray-500: #d8dee9;
  --color-accent-default:        #81a1c1;
  --color-accent-default-tint:   rgba(129,161,193,.1);
  --color-accent-note:           #5e81ac;
  --color-accent-note-tint:      rgba(94,129,172,.1);
  --color-accent-tip:            #a3be8c;
  --color-accent-tip-tint:       rgba(163,190,140,.1);
  --color-accent-important:      #b48ead;
  --color-accent-important-tint: rgba(180,142,173,.1);
  --color-accent-warning:        #d08770;
  --color-accent-warning-tint:   rgba(208,135,112,.1);
  --color-accent-caution:        #bf616a;
  --color-accent-caution-tint:   rgba(191,97,106,.1);
  --color-accent-info:           #5e81ac;
  --color-accent-info-tint:      rgba(94,129,172,.1);
  --color-accent-success:        #a3be8c;
  --color-accent-success-tint:   rgba(163,190,140,.1);
  --color-accent-danger:         #bf616a;
  --color-accent-danger-tint:    rgba(191,97,106,.1);
}

/* 当系统为深色模式但用户手动切换为浅色时，强制恢复浅色变量 */
@media (prefers-color-scheme: dark) {
  [data-theme="light"] {
    --body-background: #ffffff;
    --body-font-color: #000000;
    --color-link: #0055bb;
    --color-visited-link: #5500bb;
    --icon-filter: none;
    --gray-100: #f8f9fa;
    --gray-200: #e9ecef;
    --gray-500: #adb5bd;
    --color-accent-default:        #64748b;
    --color-accent-default-tint:   rgba(100,116,139,.1);
    --color-accent-note:           #4486dd;
    --color-accent-note-tint:      rgba(68,134,221,.1);
    --color-accent-tip:            #3bad3b;
    --color-accent-tip-tint:       rgba(59,173,59,.1);
    --color-accent-important:      #8144dd;
    --color-accent-important-tint: rgba(129,68,221,.1);
    --color-accent-warning:        #f59e42;
    --color-accent-warning-tint:   rgba(245,158,66,.1);
    --color-accent-caution:        #d84747;
    --color-accent-caution-tint:   rgba(216,71,71,.1);
    --color-accent-info:           #4486dd;
    --color-accent-info-tint:      rgba(68,134,221,.1);
    --color-accent-success:        #3bad3b;
    --color-accent-success-tint:   rgba(59,173,59,.1);
    --color-accent-danger:         #d84747;
    --color-accent-danger-tint:    rgba(216,71,71,.1);
  }
}

/* ── 主题切换按钮 ── */
.theme-toggle {
  position: fixed;
  bottom: 1.5rem;
  right: 1.5rem;
  background: var(--body-background);
  border: 1px solid var(--gray-200);
  border-radius: 50%;
  width: 2.5rem;
  height: 2.5rem;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  color: inherit;
  box-shadow: 0 2px 8px rgba(0,0,0,0.15);
  transition: opacity 0.2s;
  z-index: 1001;
}
.theme-toggle:hover {
  opacity: 0.8;
}

/* 默认（浅色）显示月亮，隐藏太阳 */
.icon-moon { display: block; }
.icon-sun  { display: none; }

/* 深色模式下显示太阳，隐藏月亮 */
[data-theme="dark"] .icon-moon { display: none; }
[data-theme="dark"] .icon-sun  { display: block; }