#header {
	display: flex;
	align-items: center;
	justify-content: center;
	flex-wrap: wrap;
	gap: 0.5rem;
	width: 100%;
	padding-bottom: 1rem;
}

#header_menu {
	display: flex;
	flex-direction: column;
	align-items: center;
	gap: 0.25rem;
	padding: 0.5rem;
}

#header_menu a {
	display: block;
	width: 100%;
	text-align: center;
	background: rgba(42, 137, 219, 1);
	color: #000;
	text-decoration: none;
	border-radius: 0.5rem;
	font-size: 1.2rem;
	text-align: left;
}

.header_item {
	width: 100%;
	padding: 0.5rem;
	border-radius: 0.5rem;
}

#header_menu a:hover {
	background-color: rgba(42, 137, 219, 0.3);
}

.header_item_selected {
	background-color: rgba(42, 137, 219, 0.3);
}

#header_image {
	display: flex;
	justify-content: center;
	align-items: center;
}

#header_image img {
	width: 100%;
	max-width: 100%;
	height: auto;
}

#menu_button {
	display: none;
	font-size: 3rem;
	width: 3.5rem;
	height: 3.5rem;
	background: none;
	border: none;
	cursor: pointer;
	position: absolute;
	top: 1rem;
	left: 1rem;
	z-index: 101;
	background-image: url('data:image/svg+xml;base64,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');
	background-size: contain;
	background-repeat: no-repeat;
}

/* メニューがアクティブなとき（開いているとき）のアイコン */
#menu_button.active {
	background-image: url('data:image/svg+xml;base64,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');
}


#back_to_top {
	position: fixed;
	bottom: 5rem;
	right: 10rem;
	background-image: url('data:image/svg+xml;base64,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');
	color: white;
	border: none;
	padding: 1rem;
	cursor: pointer;
	display: none;
	z-index: 1000;
	width: 3.5rem;
	height: 3.5rem;
	background-size: contain;
	background-repeat: no-repeat;
	border-radius: 50%;
}


@media (max-width: 1450px) {
	#header {
		flex-direction: column;
		align-items: center;
	}

	#header_menu a {
		padding: 0.3rem;
		border-radius: 0.3rem;
	}

	#header_image img {
		max-width: 100%;
		margin: auto;
	}

	#menu_button {
		display: block;
	}

	#header_menu {
		display: none;
		flex-direction: column;
		position: absolute;
		top: 60px;
		left: 0;
		background: white;
		width: fit-content;
		min-width: 30%;
		box-shadow: 4px 4px 6px rgba(0, 0, 0, 0.1);
		padding: 1rem;
		padding-left: 4rem;
		border-radius: 0.5rem;
		z-index: 100;
	}

	#header_menu.show {
		display: flex;
	}

	#back_to_top {
		right: 5rem;
	}
}

@media (max-width: 768px) {
	#back_to_top {
		right: 2.5rem;
	}
}