/**
 * Font Awesome の代替（ブランドアイコン3種のみ）
 *
 * このサイトで使っている Font Awesome のアイコンは
 * facebook / instagram / youtube の3つだけ（サイト全体を確認済み）。
 * そのために all.min.css 100KB と fa-brands-400.woff2 105KB を
 * 読み込むのは割に合わないため、SVG を直接埋め込む形に置き換えた。
 *
 * mask + currentColor にしてあるので、既存の
 *   <i class="fa-brands fa-facebook" style="color:#3B93CA">
 * のような色指定はそのまま効く。fa-2x も従来どおり。
 *
 * アイコンの形状は Font Awesome Free (CC BY 4.0) のものを使用。
 */

.fa-brands {
	display: inline-block;
	width: 1em;
	height: 1em;
	vertical-align: -0.125em;
	background-color: currentColor;
	-webkit-mask-repeat: no-repeat;
	mask-repeat: no-repeat;
	-webkit-mask-position: center;
	mask-position: center;
	-webkit-mask-size: contain;
	mask-size: contain;
}

/* Font Awesome のサイズ指定クラス（使われているものだけ） */
.fa-2x { font-size: 2em; }
.fa-lg { font-size: 1.25em; }

.fa-facebook {
	-webkit-mask-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 512 512'%3E%3Cpath d='M512 256C512 114.6 397.4 0 256 0S0 114.6 0 256C0 376 82.7 476.8 194.2 504.5V334.2H141.4V256h52.8V222.3c0-87.1 39.4-127.5 125-127.5c16.2 0 44.2 3.2 55.7 6.4V172c-6-.6-16.5-1-29.6-1c-42 0-58.2 15.9-58.2 57.2V256h83.6l-14.4 78.2H287V510.1C413.8 494.8 512 386.9 512 256z'/%3E%3C/svg%3E");
	mask-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 512 512'%3E%3Cpath d='M512 256C512 114.6 397.4 0 256 0S0 114.6 0 256C0 376 82.7 476.8 194.2 504.5V334.2H141.4V256h52.8V222.3c0-87.1 39.4-127.5 125-127.5c16.2 0 44.2 3.2 55.7 6.4V172c-6-.6-16.5-1-29.6-1c-42 0-58.2 15.9-58.2 57.2V256h83.6l-14.4 78.2H287V510.1C413.8 494.8 512 386.9 512 256z'/%3E%3C/svg%3E");
}

.fa-instagram {
	-webkit-mask-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 448 512'%3E%3Cpath d='M224.1 141c-63.6 0-114.9 51.3-114.9 114.9s51.3 114.9 114.9 114.9S339 319.5 339 255.9 287.7 141 224.1 141zm0 189.6c-41.1 0-74.7-33.5-74.7-74.7s33.5-74.7 74.7-74.7 74.7 33.5 74.7 74.7-33.6 74.7-74.7 74.7zm146.4-194.3c0 14.9-12 26.8-26.8 26.8-14.9 0-26.8-12-26.8-26.8s12-26.8 26.8-26.8 26.8 12 26.8 26.8zm76.1 27.2c-1.7-35.9-9.9-67.7-36.2-93.9-26.2-26.2-58-34.4-93.9-36.2-37-2.1-147.9-2.1-184.9 0-35.8 1.7-67.6 9.9-93.9 36.1s-34.4 58-36.2 93.9c-2.1 37-2.1 147.9 0 184.9 1.7 35.9 9.9 67.7 36.2 93.9s58 34.4 93.9 36.2c37 2.1 147.9 2.1 184.9 0 35.9-1.7 67.7-9.9 93.9-36.2 26.2-26.2 34.4-58 36.2-93.9 2.1-37 2.1-147.8 0-184.8zM398.8 388c-7.8 19.6-22.9 34.7-42.6 42.6-29.5 11.7-99.5 9-132.1 9s-102.7 2.6-132.1-9c-19.6-7.8-34.7-22.9-42.6-42.6-11.7-29.5-9-99.5-9-132.1s-2.6-102.7 9-132.1c7.8-19.6 22.9-34.7 42.6-42.6 29.5-11.7 99.5-9 132.1-9s102.7-2.6 132.1 9c19.6 7.8 34.7 22.9 42.6 42.6 11.7 29.5 9 99.5 9 132.1s2.7 102.7-9 132.1z'/%3E%3C/svg%3E");
	mask-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 448 512'%3E%3Cpath d='M224.1 141c-63.6 0-114.9 51.3-114.9 114.9s51.3 114.9 114.9 114.9S339 319.5 339 255.9 287.7 141 224.1 141zm0 189.6c-41.1 0-74.7-33.5-74.7-74.7s33.5-74.7 74.7-74.7 74.7 33.5 74.7 74.7-33.6 74.7-74.7 74.7zm146.4-194.3c0 14.9-12 26.8-26.8 26.8-14.9 0-26.8-12-26.8-26.8s12-26.8 26.8-26.8 26.8 12 26.8 26.8zm76.1 27.2c-1.7-35.9-9.9-67.7-36.2-93.9-26.2-26.2-58-34.4-93.9-36.2-37-2.1-147.9-2.1-184.9 0-35.8 1.7-67.6 9.9-93.9 36.1s-34.4 58-36.2 93.9c-2.1 37-2.1 147.9 0 184.9 1.7 35.9 9.9 67.7 36.2 93.9s58 34.4 93.9 36.2c37 2.1 147.9 2.1 184.9 0 35.9-1.7 67.7-9.9 93.9-36.2 26.2-26.2 34.4-58 36.2-93.9 2.1-37 2.1-147.8 0-184.8zM398.8 388c-7.8 19.6-22.9 34.7-42.6 42.6-29.5 11.7-99.5 9-132.1 9s-102.7 2.6-132.1-9c-19.6-7.8-34.7-22.9-42.6-42.6-11.7-29.5-9-99.5-9-132.1s-2.6-102.7 9-132.1c7.8-19.6 22.9-34.7 42.6-42.6 29.5-11.7 99.5-9 132.1-9s102.7-2.6 132.1 9c19.6 7.8 34.7 22.9 42.6 42.6 11.7 29.5 9 99.5 9 132.1s2.7 102.7-9 132.1z'/%3E%3C/svg%3E");
}

.fa-youtube {
	-webkit-mask-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 576 512'%3E%3Cpath d='M549.7 124.1c-6.3-23.7-24.8-42.3-48.3-48.6C458.8 64 288 64 288 64S117.2 64 74.6 75.5c-23.5 6.3-42 24.9-48.3 48.6-11.4 42.9-11.4 132.3-11.4 132.3s0 89.4 11.4 132.3c6.3 23.7 24.8 41.5 48.3 47.8C117.2 448 288 448 288 448s170.8 0 213.4-11.5c23.5-6.3 42-24.1 48.3-47.8 11.4-42.9 11.4-132.3 11.4-132.3s0-89.4-11.4-132.3zm-317.5 213.5V175.2l142.7 81.2-142.7 81.2z'/%3E%3C/svg%3E");
	mask-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 576 512'%3E%3Cpath d='M549.7 124.1c-6.3-23.7-24.8-42.3-48.3-48.6C458.8 64 288 64 288 64S117.2 64 74.6 75.5c-23.5 6.3-42 24.9-48.3 48.6-11.4 42.9-11.4 132.3-11.4 132.3s0 89.4 11.4 132.3c6.3 23.7 24.8 41.5 48.3 47.8C117.2 448 288 448 288 448s170.8 0 213.4-11.5c23.5-6.3 42-24.1 48.3-47.8 11.4-42.9 11.4-132.3 11.4-132.3s0-89.4-11.4-132.3zm-317.5 213.5V175.2l142.7 81.2-142.7 81.2z'/%3E%3C/svg%3E");
}