/* Font Awesome 图标备用方案 - 优化版本 */

/* 基础备用图标样式 */
.fa-fallback {
    font-family: 'Apple Color Emoji', 'Segoe UI Emoji', 'Noto Color Emoji', 'Segoe UI Symbol', sans-serif;
    font-weight: normal;
    display: inline-block;
    font-style: normal;
    font-variant: normal;
    text-rendering: auto;
    line-height: 1;
    font-size: 1em;
}

/* 当Font Awesome无法加载时的备用图标 */
.fa {
    font-family: 'Font Awesome 6 Free', 'Font Awesome 6 Pro', 'Font Awesome 5 Free', 'Font Awesome 5 Pro', 'Apple Color Emoji', 'Segoe UI Emoji', 'Noto Color Emoji', Arial, sans-serif;
    font-weight: 900;
    display: inline-block;
    font-style: normal;
    font-variant: normal;
    text-rendering: auto;
    line-height: 1;
}

/* 备用图标定义 - 使用Unicode字符和文本符号 */
.fa-broadcast-tower::before { content: "📡"; }
.fa-chart-line::before { content: "📈"; }
.fa-chart-area::before { content: "📊"; }
.fa-chart-bar::before { content: "📊"; }
.fa-cog::before { content: "⚙"; }
.fa-coins::before { content: "💰"; }
.fa-tools::before { content: "🔧"; }
.fa-bolt::before { content: "⚡"; }
.fa-recycle::before { content: "♻"; }
.fa-bullhorn::before { content: "📢"; }
.fa-calculator::before { content: "🧮"; }
.fa-layer-group::before { content: "📚"; }
.fa-solar-panel::before { content: "☀"; }
.fa-network-wired::before { content: "🌐"; }
.fa-industry::before { content: "🏭"; }
.fa-money-bill-wave::before { content: "💵"; }
.fa-clock::before { content: "🕐"; }
.fa-dollar-sign::before { content: "$"; }
.fa-cogs::before { content: "⚙"; }
.fa-plug::before { content: "🔌"; }
.fa-info-circle::before { content: "ℹ"; }
.fa-check-circle::before { content: "✓"; }
.fa-plus-circle::before { content: "+"; }
.fa-home::before { content: "🏠"; }
.fa-download::before { content: "⬇"; }
.fa-upload::before { content: "⬆"; }
.fa-save::before { content: "💾"; }
.fa-folder-open::before { content: "📁"; }
.fa-plus::before { content: "+"; }
.fa-minus::before { content: "-"; }
.fa-times::before { content: "×"; }
.fa-check::before { content: "✓"; }
.fa-exclamation-triangle::before { content: "⚠"; }
.fa-question-circle::before { content: "?"; }
.fa-leaf::before { content: "🍃"; }
.fa-sun::before { content: "☀"; }
.fa-wind::before { content: "💨"; }
.fa-battery-half::before { content: "🔋"; }
.fa-file-alt::before { content: "📄"; }
.fa-percentage::before { content: "%"; }
.fa-chart-pie::before { content: "🥧"; }
.fa-tachometer-alt::before { content: "⏱"; }
.fa-gift::before { content: "🎁"; }
.fa-chart-line-down::before { content: "📉"; }

/* 确保图标正确显示 */
.fa[class*="fa-"]::before {
    font-size: inherit;
    line-height: inherit;
    vertical-align: baseline;
}

/* 当Font Awesome加载失败时的样式调整 */
@supports not (font-family: 'Font Awesome 6 Free') {
    .fa::before {
        font-family: 'Apple Color Emoji', 'Segoe UI Emoji', 'Noto Color Emoji', 'Segoe UI Symbol', sans-serif;
        font-weight: normal;
    }
}

/* 针对不支持彩色emoji的浏览器的备用方案 */
@media (prefers-color-scheme: dark) {
    .fa::before {
        filter: brightness(0.9);
    }
}