【参考】cssだけでcheckboxやradioのデザインを変更 – WEBdev
この記事がとても参考になり、発見もあったので、「cssだけでcheckboxやradioのデザインを変更」を書き砕いてみます。

• input[type=”radio”]について
• input[type=”checkbox”]について

input[type=”radio”]について

DEMO

HTML

<input type="radio" name="radio01" id="radio01_yes"><label for="radio01_yes">らじおぼたん</label>

SASS

input[type="radio"] {
	display: inline-block;
	margin-right: 6px;
	& + label {
		position: relative;
		display: inline-block;
		margin-right: 12px;
		font-size: 14px;
		font-size: 1.4rem;
		line-height: 2;
		cursor: pointer;
		vertical-align: middle;
	}
	@media screen and (max-width:スマホ切り替えサイズ) {
		& + label {
			margin-right: 12px;
			font-size: 12px;
			font-size: 1.2rem;
			line-height: 1.25;
		}
	}
}
@media (min-width: 1px) {
	input[type="radio"] {
		display: none;
		margin: 0;
		&:checked + label::after {
			content: "";
			position: absolute;
			top: 50%;
			box-sizing: border-box;
			display: block;
		}
		& + label::before {
			content: "";
			position: absolute;
			top: 50%;
			left: 0;
			box-sizing: border-box;
			display: block;
			background: #ffffff;
		}
	}
	input[type="radio"] {
		& + label {
			padding: 0 10px 0 31px;
			line-height: 22px;
		}
		& + label::before {
			width: 22px;
			height: 22px;
			margin-top: -11px;
		}
		@media screen and (max-width:スマホ切り替えサイズ) {
			& + label {
				padding: 0 0 0 27px;
				line-height: 18px;
			}
			& + label::before {
				width: 18px;
				height: 18px;
				margin-top: -9px;
			}
		}
	}
	input[type="radio"][disabled] {
		cursor: default;
	}
	input[type="radio"] + label {
		background: none;
	}
	input[type="radio"][disabled] + label {
		color: #999999;
		cursor: default;
	}
	input[type="radio"] + label::before {
		border: 2px solid #cccccc;
		border-radius: 30px;
		@media screen and (max-width:スマホ切り替えサイズ) {
			border-width: 1px;
		}
	}
	input[type="radio"][disabled] + label::before {
		border-color: #999999;
	}
	input[type="radio"]:checked + label::before {
		border-color: #5e942e;
		background-color: #e3eeda;
	}
	input[type="radio"][disabled]:checked + label::before {
		border-color: #999999;
		background-color: #ffffff;
	}
	input[type="radio"]:checked + label::after {
		left: 8px;
		width: 6px;
		height: 6px;
		margin-top: -3px;
		background: #5e942e;
		border-radius: 6px;
		@media screen and (max-width:スマホ切り替えサイズ) {
			left: 6px;
			width: 5px;
			height: 5px;
			border-radius: 5px;
		}
	}
	input[type="radio"][disabled]:checked + label::after {
		background: #999999;
	}
}

図解

まず、最初にinput[type=”radio”]は「display: none;」で非表示にしてから、labelとlabelの疑似要素を使用してスタイルをつけて行きます。

input[type="radio"] {
		display: none;
		& + label::before {
			display: block;

@media (min-width: 1px)
input[type="radio"] + label {
    padding: 0 10px 0 31px;
    line-height: 22px;
}

@media (min-width: 1px) input[type="radio"] + label::before { width: 22px; height: 22px; margin-top: -11px; border: 2px solid #cccccc; border-radius: 30px; }

	@media (min-width: 1px) input[type="radio"]:checked + label::before { border-color: #5e942e; background-color: #e3eeda; }
	@media (min-width: 1px) input[type="radio"]:checked + label::after { left: 8px; width: 6px; height: 6px; margin-top: -3px; background: #5e942e; border-radius: 6px; }

input[type=”checkbox”]について

DEMO

HTML

<input type="checkbox" id="namae1"><label for="namae1">ちぇっくぼっくす</label>

SASS

input[type="checkbox"] {
	display: inline-block;
	margin-right: 6px;
	& + label {
		position: relative;
		display: inline-block;
		margin-right: 12px;
		font-size: 14px;
		font-size: 1.4rem;
		line-height: 2;
		cursor: pointer;
		vertical-align: middle;
	}
	@media screen and (max-width:スマホ切り替えサイズ) {
		& + label {
			margin-right: 12px;
			font-size: 12px;
			font-size: 1.2rem;
			line-height: 1.25;
		}
	}
}
@media (min-width: 1px) {
	input[type="checkbox"] {
		display: none;
		margin: 0;
		&:checked + label::after {
			content: "";
			position: absolute;
			top: 50%;
			box-sizing: border-box;
			display: block;
		}
		& + label::before {
			content: "";
			position: absolute;
			top: 50%;
			left: 0;
			box-sizing: border-box;
			display: block;
			background: #ffffff;
		}
	}
	input[type="checkbox"] {
		& + label {
			padding: 0 10px 0 32px;
			line-height: 22px;
		}
		& + label::before {
			width: 22px;
			height: 22px;
			margin-top: -11px;
		}
		@media screen and (max-width:スマホ切り替えサイズ) {
			& + label {
				padding: 0 10px 0 25px;
				line-height: 15px;
			}
			& + label::before {
				width: 15px;
				height: 15px;
				margin-top: -7.5px;
			}
		}
	}
	input[type="checkbox"] + label::before {
		border-radius: 4px;
		border: 2px solid #cccccc;
		@media screen and (max-width:スマホ切り替えサイズ) {
			border-radius: 2.5px;
			border-width: 1px;
		}
	}
	input[type="checkbox"]:checked + label::before, {
		border-color: #5e942e;
		background-color: #e3eeda;
	}
	input[type="checkbox"]:checked + label::after {
		left: 6px;
		width: 10px;
		height: 6px;
		margin-top: -5px;
		border-left: 3px solid #5e942e;
		border-bottom: 3px solid #5e942e;
		transform: rotate(-45deg);
		-webkit-transform: rotate(-45deg);
		@media screen and (max-width:スマホ切り替えサイズ) {
			left: 4px;
			width: 8px;
			height: 6px;
			margin-top: -4px;
			border-left-width: 2px;
			border-bottom-width: 2px;
		}
	}
}

図解

まず、最初にinput[type=”checkbox”]は「display: none;」で非表示にしてから、labelとlabelの疑似要素を使用してスタイルをつけて行きます。

	input[type="checkbox"] {
		display: none;
		&:checked + label::after {
			display: block;
		}
		& + label::before {
			display: block;
		}

@media (min-width: 1px)
input[type="checkbox"] + label {
    padding: 0 10px 0 32px;
    line-height: 22px;
}

@media (min-width: 1px) input[type="checkbox"] + label::before { border-radius: 4px; border: 2px solid #cccccc; width: 22px; height: 22px; margin-top: -11px; }

	@media (min-width: 1px) input[type="checkbox"]:checked + label::before { border-color: #5e942e; background-color: #e3eeda; }
	@media (min-width: 1px) input[type="checkbox"]:checked + label::after { left: 6px; width: 10px; height: 6px; margin-top: -5px; border-left: 3px solid #5e942e; border-bottom: 3px solid #5e942e; transform: rotate(-45deg); -webkit-transform: rotate(-45deg); }