:root {
	--ink: #22313f;
	--muted: #5d6a75;
	--line: #dbe4eb;
	--blue: #2e6da4;
	--blue-deep: #173a56;
	--blue-soft: #eef5fb;
	--bg: #f7fafc;
	--card: #ffffff;
	--code-bg: #203447;
	--code-line: #35526b;
	--code-ink: #f8fbff;
}

* { box-sizing: border-box; }

body {
	margin: 0;
	font-family: 'Calibri', 'Arial', sans-serif;
	color: var(--ink);
	background: linear-gradient(180deg, #fbfdff 0%, var(--bg) 100%);
}

.page {
	max-width: 820px;
	margin: 0 auto;
	padding: 28px 20px 56px;
}

.back-link {
	display: inline-block;
	margin-bottom: 18px;
	color: var(--blue);
	text-decoration: none;
	font-size: 14px;
	font-weight: 700;
}

.back-link:hover { text-decoration: underline; }

.chapter-hero {
	background: var(--card);
	border: 1px solid var(--line);
	border-radius: 18px;
	padding: 28px 24px 24px;
	margin-bottom: 22px;
}

.chapter-hero.has-hero-img {
	display: flex;
	flex-direction: column;
	align-items: center;
}

.chapter-hero .hero-img {
	width: 280px;
	max-width: 60%;
	height: auto;
	border-radius: 12px;
	margin-top: 12px;
}

.eyebrow {
	margin: 0 0 8px;
	font-size: 13px;
	font-weight: 700;
	color: var(--blue);
}

.chapter-hero h1 {
	margin: 0 0 10px;
	font-size: 34px;
	line-height: 1.2;
	color: var(--blue-deep);
}

.chapter-hero p {
	margin: 0;
	font-size: 16px;
	line-height: 1.8;
	color: var(--muted);
}

.content-section {
	background: var(--card);
	border: 1px solid var(--line);
	border-radius: 18px;
	padding: 22px 24px;
	margin-bottom: 18px;
}

.content-section h2 {
	margin: 0 0 10px;
	font-size: 22px;
	line-height: 1.3;
	color: var(--blue-deep);
}

.content-section p,
.content-section li {
	font-size: 15px;
	line-height: 1.8;
	color: var(--ink);
}

.content-section p {
	margin: 0;
}

.content-section p + p {
	margin-top: 10px;
}

.point-list {
	margin: 0;
	padding-left: 1.2rem;
}

.point-list li + li {
	margin-top: 8px;
}

.code-inline {
	font-family: 'Consolas', 'Menlo', monospace;
	font-size: 14px;
}

/* ── code-wrap: コピーボタン付きコードブロック ── */
.code-wrap {
	position: relative;
	margin: 10px 0 12px;
}

.code-wrap pre {
	margin: 0;
	padding: 16px 18px;
	padding-right: 72px;
	border-radius: 14px;
	background: var(--code-bg);
	border: 1px solid var(--code-line);
	color: var(--code-ink);
	overflow-x: auto;
}

.code-wrap pre code {
	font-family: 'Consolas', 'Menlo', monospace;
	font-size: 14px;
	white-space: pre;
	display: block;
	line-height: 1.7;
	color: inherit;
}

.copy-btn {
	position: absolute;
	top: 8px;
	right: 8px;
	padding: 4px 12px;
	border: 1px solid rgba(255,255,255,0.25);
	border-radius: 8px;
	background: rgba(255,255,255,0.1);
	color: rgba(255,255,255,0.7);
	font-family: inherit;
	font-size: 12px;
	font-weight: 600;
	cursor: pointer;
	transition: background 0.15s, color 0.15s;
	user-select: none;
}

.copy-btn:hover {
	background: rgba(255,255,255,0.2);
	color: #fff;
}

.copy-btn.copied {
	background: #2E7D32;
	border-color: #2E7D32;
	color: #fff;
}

.code-inline {
	display: inline-block;
	padding: 0.08em 0.42em;
	border-radius: 0.45em;
	background: var(--blue-soft);
	color: var(--blue-deep);
}

.chapter-nav {
	display: flex;
	flex-wrap: wrap;
	gap: 12px;
	justify-content: space-between;
	margin-top: 28px;
}

.chapter-nav a {
	display: inline-block;
	padding: 10px 16px;
	border: 1px solid var(--line);
	border-radius: 999px;
	background: var(--card);
	color: var(--blue-deep);
	text-decoration: none;
	font-size: 14px;
	font-weight: 700;
}

.chapter-nav a:hover {
	border-color: var(--blue);
	color: var(--blue);
}

.chapter-nav .primary {
	background: var(--blue);
	border-color: var(--blue);
	color: #fff;
}

.chapter-nav .primary:hover {
	opacity: 0.92;
	color: #fff;
}

/* ── info-box: 前提条件・注意枠 ── */
.info-box {
	margin: 0 0 20px;
	padding: 14px 18px;
	border-radius: 12px;
	background: #FFF3E0;
	border-left: 5px solid #E65100;
	font-size: 14px;
	line-height: 1.7;
	color: var(--ink);
}

.info-box strong {
	color: #BF360C;
}

/* ── flow-steps: 横並び流れ図 ── */
.flow-steps {
	display: flex;
	flex-wrap: wrap;
	align-items: center;
	gap: 6px;
	margin: 14px 0;
}

.flow-steps .step {
	display: inline-flex;
	align-items: center;
	padding: 6px 14px;
	border-radius: 10px;
	background: var(--blue-soft);
	color: var(--blue-deep);
	font-size: 14px;
	font-weight: 700;
	white-space: nowrap;
}

.flow-steps .arrow {
	font-size: 16px;
	color: var(--muted);
	user-select: none;
}

/* ── output-example: 実行結果例 ── */
.output-example {
	margin: 10px 0 12px;
	padding: 12px 16px;
	border-radius: 12px;
	background: #f0f4f8;
	border: 1px solid var(--line);
	font-family: 'Consolas', 'Menlo', monospace;
	font-size: 13px;
	line-height: 1.7;
	color: var(--ink);
	white-space: pre-wrap;
}

/* ── safe-box: 安心導線 ── */
.safe-box {
	margin: 12px 0;
	padding: 14px 18px;
	border-radius: 12px;
	background: #eaf7ec;
	border-left: 4px solid #4caf50;
	font-size: 14px;
	line-height: 1.7;
	color: #2e5c31;
}

/* ── term-card: 用語カード ── */
.term-card {
	display: grid;
	grid-template-columns: auto 1fr;
	gap: 4px 14px;
	margin: 12px 0;
	padding: 14px 18px;
	border-radius: 12px;
	background: var(--blue-soft);
	border: 1px solid var(--line);
	font-size: 14px;
	line-height: 1.7;
}

.term-card dt {
	font-weight: 700;
	color: var(--blue-deep);
}

.term-card dd {
	margin: 0;
	color: var(--ink);
}

/* ── shape-table: shape 対応表 ── */
.shape-table {
	width: 100%;
	border-collapse: collapse;
	margin: 12px 0;
	font-size: 14px;
}

.shape-table th,
.shape-table td {
	padding: 8px 12px;
	border: 1px solid var(--line);
	text-align: left;
}

.shape-table th {
	background: var(--blue-soft);
	color: var(--blue-deep);
	font-weight: 700;
}

.shape-table td {
	background: var(--card);
}

/* ── check-list: チェックリスト ── */
.check-list {
	margin: 10px 0;
	padding-left: 0;
	list-style: none;
}

.check-list li {
	padding: 4px 0 4px 1.6em;
	position: relative;
	font-size: 14px;
	line-height: 1.7;
}

.check-list li::before {
	content: '☐';
	position: absolute;
	left: 0;
	color: var(--blue);
}

/* ── error-line: エラー出力マーキング ── */
.error-line {
	display: block;
	padding: 2px 8px;
	margin: 0 -8px;
	border-radius: 4px;
}

.error-line.highlight {
	background: #fff3e0;
	border-left: 3px solid #ff9800;
}

/* ── details-fold: 折りたたみセクション ── */
.content-section details {
	margin-top: 12px;
}

.content-section details summary {
	cursor: pointer;
	font-weight: 700;
	font-size: 15px;
	color: var(--blue);
	padding: 6px 0;
	user-select: none;
	list-style: revert;
}

.content-section details summary:hover {
	text-decoration: underline;
}

.content-section details[open] > summary {
	margin-bottom: 8px;
}

@media (max-width: 640px) {
	.page { padding: 22px 16px 48px; }
	.chapter-hero,
	.content-section { padding: 22px 18px; }
	.chapter-hero h1 { font-size: 29px; }
	.chapter-hero.has-hero-img {
		align-items: center;
	}
	.chapter-hero .hero-img {
		width: 180px;
		max-width: 50%;
	}
	.content-section h2 { font-size: 20px; }
	.chapter-nav { justify-content: flex-start; }
	.flow-steps { gap: 4px; }
	.flow-steps .step { padding: 5px 10px; font-size: 13px; }
	.term-card { grid-template-columns: 1fr; }
}