/* 本地图标替代方案 - 使用 Data URI SVG 模拟 Font Awesome */
.fa {
  display: inline-block;
  width: 14px;
  height: 14px;
  background-repeat: no-repeat;
  background-position: center;
  background-size: contain;
  vertical-align: middle;
  position: relative;
  top: -1px;
}

/* 兼容 EasyMDE 的类名 */
.fa-bold { background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%23333' stroke-width='2.5' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='M6 4h8a4 4 0 0 1 4 4 4 4 0 0 1-4 4H6z'/%3E%3Cpath d='M6 12h9a4 4 0 0 1 4 4 4 4 0 0 1-4 4H6z'/%3E%3C/svg%3E"); }
.fa-italic { background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%23333' stroke-width='2.5' stroke-linecap='round' stroke-linejoin='round'%3E%3Cline x1='19' y1='4' x2='10' y2='4'/%3E%3Cline x1='14' y1='20' x2='5' y2='20'/%3E%3Cline x1='15' y1='4' x2='9' y2='20'/%3E%3C/svg%3E"); }
.fa-header, .fa-heading { background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%23333' stroke-width='2.5' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='M6 12h12M6 20V4M18 20V4'/%3E%3C/svg%3E"); }
.fa-quote-left { background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%23333' stroke-width='2.5' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='M3 21c3 0 7-1 7-8V5H3v8h4c0 4.5-2 5-4 5z'/%3E%3Cpath d='M14 21c3 0 7-1 7-8V5h-7v8h4c0 4.5-2 5-4 5z'/%3E%3C/svg%3E"); }
.fa-list-ul { background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%23333' stroke-width='2.5' stroke-linecap='round' stroke-linejoin='round'%3E%3Cline x1='8' y1='6' x2='21' y2='6'/%3E%3Cline x1='8' y1='12' x2='21' y2='12'/%3E%3Cline x1='8' y1='18' x2='21' y2='18'/%3E%3Ccircle cx='3' cy='6' r='1'/%3E%3Ccircle cx='3' cy='12' r='1'/%3E%3Ccircle cx='3' cy='18' r='1'/%3E%3C/svg%3E"); }
.fa-list-ol { background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%23333' stroke-width='2.5' stroke-linecap='round' stroke-linejoin='round'%3E%3Cline x1='10' y1='6' x2='21' y2='6'/%3E%3Cline x1='10' y1='12' x2='21' y2='12'/%3E%3Cline x1='10' y1='18' x2='21' y2='18'/%3E%3Cpath d='M4 6h1v4M4 10h2'/%3E%3Cpath d='M6 18H4c0-1 2-2 2-3s-1-1.5-2-1'/%3E%3C/svg%3E"); }
.fa-link { background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%23333' stroke-width='2.5' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='M10 13a5 5 0 0 0 7.54.54l3-3a5 5 0 0 0-7.07-7.07l-1.72 1.71'/%3E%3Cpath d='M14 11a5 5 0 0 0-7.54-.54l-3 3a5 5 0 0 0 7.07 7.07l1.71-1.71'/%3E%3C/svg%3E"); }
.fa-image { background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%23333' stroke-width='2.5' stroke-linecap='round' stroke-linejoin='round'%3E%3Crect x='3' y='3' width='18' height='18' rx='2' ry='2'/%3E%3Ccircle cx='8.5' cy='8.5' r='1.5'/%3E%3Cpolyline points='21 15 16 10 5 21'/%3E%3C/svg%3E"); }
.fa-eye { background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%23333' stroke-width='2.5' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='M1 12s4-8 11-8 11 8 11 8-4 8-11 8-11-8-11-8z'/%3E%3Ccircle cx='12' cy='12' r='3'/%3E%3C/svg%3E"); }
.fa-columns { background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%23333' stroke-width='2.5' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='M12 3v18M3 3h18v18H3z'/%3E%3C/svg%3E"); }
.fa-arrows-alt { background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%23333' stroke-width='2.5' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpolyline points='15 3 21 3 21 9'/%3E%3Cpolyline points='9 21 3 21 3 15'/%3E%3Cline x1='21' y1='3' x2='14' y2='10'/%3E%3Cline x1='3' y1='21' x2='10' y2='14'/%3E%3C/svg%3E"); }
.fa-question-circle { background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%23333' stroke-width='2.5' stroke-linecap='round' stroke-linejoin='round'%3E%3Ccircle cx='12' cy='12' r='10'/%3E%3Cpath d='M9.09 9a3 3 0 0 1 5.83 1c0 2-3 3-3 3'/%3E%3Cline x1='12' y1='17' x2='12.01' y2='17'/%3E%3C/svg%3E"); }

/* 暗色模式适配 */
@media (prefers-color-scheme: dark) {
  .fa { filter: invert(0.8); }
}