<div class="cp_iptxt">
<input class="ef" type="text" placeholder="">
<label>お名前</label>
<span class="focus_line"><i></i></span>
</div>

.cp_iptxt {
	position: relative;
	width: 80%;
	margin: 40px 3%;
}
.cp_iptxt input[type='text'] {
	font: 15px/24px sans-serif;
	box-sizing: border-box;
	width: 100%;
	letter-spacing: 1px;
	padding-left: 4em;
}
.cp_iptxt input[type='text']:focus {
	outline: none;
}
.ef {
	padding: 7px 14px;
	transition: 0.4s;
	border: 1px solid #1b2538;
	background: transparent;
}
.ef ~ .focus_line:before,
.ef ~ .focus_line:after {
	position: absolute;
	top: 0;
	right: 0;
	width: 0;
	height: 2px;
	content: '';
	transition: 0.2s;
	transition-delay: 0.2s;
	background-color: #da3c41;
}
.ef ~ .focus_line:after {
	top: auto;
	right: auto;
	bottom: 0;
	left: 0;
	transition-delay: 0.6s;
}
.ef ~ .focus_line i:before,
.ef ~ .focus_line i:after {
	position: absolute;
	top: 0;
	left: 0;
	width: 2px;
	height: 0;
	content: '';
	transition: 0.2s;
	background-color: #da3c41;
}
.ef ~ .focus_line i:after {
	top: auto;
	right: 0;
	bottom: 0;
	left: auto;
	transition-delay: 0.4s;
}
.ef:focus ~ .focus_line:before,
.ef:focus ~ .focus_line:after,
.cp_iptxt.ef ~ .focus_line:before,
.cp_iptxt.ef ~ .focus_line:after {
	width: 100%;
	transition: 0.2s;
	transition-delay: 0.6s;
}
.ef:focus ~ .focus_line:after,
.cp_iptxt.ef ~ .focus_line:after {
	transition-delay: 0.2s;
}
.ef:focus ~ .focus_line i:before,
.ef:focus ~ .focus_line i:after,
.cp_iptxt.ef ~ .focus_line i:before,
.cp_iptxt.ef ~ .focus_line i:after {
	height: 100%;
	transition: 0.2s;
}
.ef:focus ~ .focus_line i:after,
.cp_iptxt.ef ~ .focus_line i:after {
	transition-delay: 0.4s;
}
.ef ~ label {
	position: absolute;
	z-index: -1;
	top: 10px;
	left: 14px;
	width: 100%;
	transition: 0.3s;
	letter-spacing: 0.5px;
	color: #aaaaaa;
}
.ef:focus ~ label, .cp_iptxt.ef ~ label {
	font-size: px;
	top: -18px;
	left: 0;
	transition: 0.3s;
	color: #da3c41;
}