/* title */
.title-area {
	max-width: 1140px;
	width: calc(100% - 40px);
	margin: 179px auto 62px;
}

@media screen and (max-width: 540px) {
	.title-area {
		width: calc(100% - 20px);
		margin: 146px auto 32px;
		text-align: center;
	}
}

.title-sub {
	font-size: 21.61px;
	color: #777777;
	position: relative;
	padding-left: 18px;
	font-weight: 500;
}

.title-sub::before {
	content: "";
	display: block;
	width: 6.75px;
	height: 6.75px;
	background-color: #cb2020;
	border-radius: 1.35px;
	position: absolute;
	left: 0;
	top: 50%;
	transform: translateY(-50%);
}

.title-main {
	font-size: 64px;
	font-weight: 900;
	color: #1a1a1a;
	margin-top: 10px;
	line-height: 1.2;
	letter-spacing: 1px;
}

/* コラム一覧 */
.column-page-container {
	max-width: 1100px;
	/* margin: 60px auto;
	padding: 0 40px; */
	margin: 0 auto;
	padding: 200px 40px 0;
}

/* Column Header
-------------------------------------------------- */
.column-header {
	margin-bottom: 40px;
	position: relative;
	padding-left: 15px;
}

.column-header::before {
	content: "";
	display: block;
	width: 6.75px;
	height: 6.75px;
	border-radius: 1.35px;
	background-color: #cb2020; /* アクセントの赤色 */
	position: absolute;
	top: 9px;
	left: 0;
	margin-left: 2%;
}

.column-header-ja {
	font-size: 14px;
	font-weight: normal;
	color: #555;
	margin: 0;
	margin-left: 2%;
}

.column-header-en {
	font-size: 48px;
	font-weight: bold;
	color: #222;
	display: block;
	line-height: 1.2;
}

/* Column Grid Layout
-------------------------------------------------- */
.column-grid {
	display: grid;
	grid-template-columns: repeat(3, 1fr);
	gap: 30px;
}

/* Column Item (Card)
-------------------------------------------------- */
.column-item {
	background-color: #fff;
	border-radius: 8px;
	overflow: hidden;
	box-shadow: 0 4px 15px rgba(0, 0, 0, 0.05);
	transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.column-item:hover {
	transform: translateY(-5px);
	box-shadow: 0 8px 25px rgba(0, 0, 0, 0.1);
}

.column-item-link {
	text-decoration: none;
	color: inherit;
	display: block;
}

.column-item-thumbnail img {
	width: 100%;
	height: auto;
	display: block;
	aspect-ratio: 16 / 10;
	object-fit: cover;
}

.column-item-content {
	padding: 20px;
}

.column-item-title {
	font-size: 16px;
	font-weight: bold;
	line-height: 1.5;
	margin: 0 0 8px 0;
	color: #333;
}

.column-item-date {
	font-size: 12px;
	color: #888;
	display: block;
	margin-bottom: 12px;
}

.column-item-excerpt {
	font-size: 14px;
	color: #555;
	line-height: 1.7;
	margin: 0;
}

/* Pagination
-------------------------------------------------- */
.column-pagination {
	margin-top: 60px;
	text-align: center;
}

.column-pagination .page-numbers {
	display: inline-block;
	padding: 8px 18px;
	margin: 0 4px;
	border-radius: 50%;
	text-decoration: none;
	color: #333;
	background-color: #fff;
	transition: background-color 0.3s, color 0.3s;
}

.column-pagination .page-numbers:hover {
	background-color: #eee;
}

.column-pagination .page-numbers.current {
	background-color: #cb2020; /* アクティブなページの色 */
	color: #fff;
	font-weight: bold;
}

.column-pagination .prev,
.column-pagination .next {
	font-weight: bold;
	color: #cb2020;
	background-color: #ffffff00;
}

.column-pagination .prev:hover,
.column-pagination .next:hover {
	background-color: #ffffff00;
	color: #cb2020c2;
}

/* Back to Top Button
-------------------------------------------------- */
.back-to-top-button {
	position: fixed;
	bottom: 30px;
	right: 30px;
	background-color: #333;
	color: #fff;
	padding: 12px 20px;
	border-radius: 4px;
	text-decoration: none;
	font-size: 14px;
	font-weight: bold;
	box-shadow: 0 2px 10px rgba(0, 0, 0, 0.2);
	opacity: 0; /* 最初は非表示 */
	visibility: hidden;
	transition: opacity 0.3s, visibility 0.3s;
}

.back-to-top-button.show {
	opacity: 1;
	visibility: visible;
}

/* Responsive (for tablet and mobile)
-------------------------------------------------- */
@media (max-width: 992px) {
	.column-grid {
		grid-template-columns: repeat(2, 1fr);
	}
}

@media (max-width: 768px) {
	.column-page-container {
		padding: 0 20px;
		margin: 150px auto;
	}
	.column-header-en {
		font-size: 36px;
	}
	.column-grid {
		grid-template-columns: 1fr;
		gap: 20px;
	}
}