/* ==========================================================================
   SoDinhDanh Encyclopedia — Design tokens
   Ý tưởng: "sổ tra cứu / thẻ mục lục hành chính" — mỗi bài viết là một mục
   được đánh SỐ ĐỊNH DANH riêng (mã tra cứu dạng SĐD-A01), như thẻ trong tủ
   hồ sơ. Con dấu đỏ = tính pháp lý/chính thống. Navy = tin cậy, nhà nước.
   Monospace cho mọi con số/mã — tách bạch "số" khỏi "chữ" đúng tinh thần
   chủ đề định danh.
   ========================================================================== */
:root {
	/* Màu */
	--ink:        #1B2436;   /* chữ chính */
	--ink-soft:   #4A5568;   /* chữ phụ */
	--paper:      #F3F4F0;   /* nền trang — giấy hồ sơ, không phải cream ấm */
	--paper-card: #FFFFFF;
	--navy:       #1E3A5F;   /* thương hiệu, liên kết, header */
	--navy-deep:  #142842;
	--stamp:      #A8322B;   /* đỏ con dấu — dùng rất tiết chế: mã tra cứu, nhãn "Chính thức" */
	--stamp-soft: #F3E3E1;
	--teal:       #1F6F5C;   /* trạng thái tra cứu / thành công */
	--line:       #D8DBD2;   /* viền, gạch chấm kiểu giấy kẻ */
	--line-soft:  #E7E8E2;

	/* Typography */
	--font-display: 'Source Serif 4', Georgia, serif;
	--font-body: 'Be Vietnam Pro', -apple-system, sans-serif;
	--font-mono: 'JetBrains Mono', ui-monospace, monospace;

	--radius: 3px;
	--container: 1180px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
	margin: 0;
	font-family: var(--font-body);
	color: var(--ink);
	background: var(--paper);
	background-image:
		linear-gradient(var(--line-soft) 1px, transparent 1px);
	background-size: 100% 2.1em;
	background-attachment: local;
	line-height: 1.65;
	font-size: 16px;
}
img { max-width: 100%; display: block; }
a { color: var(--navy); text-decoration: none; }
a:hover { text-decoration: underline; }
:focus-visible { outline: 2px solid var(--stamp); outline-offset: 2px; }
.container { max-width: var(--container); margin: 0 auto; padding: 0 24px; }

h1, h2, h3, h4 {
	font-family: var(--font-display);
	color: var(--navy-deep);
	line-height: 1.25;
	font-weight: 600;
	margin: 1.6em 0 0.6em;
}
h1 { font-size: 2.3rem; margin-top: 0; }
h2 { font-size: 1.55rem; padding-top: 0.4em; border-top: 1px dashed var(--line); }
h3 { font-size: 1.2rem; }
p { margin: 0 0 1.1em; }

/* ---------- Mã tra cứu / stamp badge — SIGNATURE ELEMENT ---------- */
.sdd-code {
	display: inline-flex;
	align-items: center;
	gap: 6px;
	font-family: var(--font-mono);
	font-weight: 600;
	font-size: 0.78rem;
	letter-spacing: 0.04em;
	color: var(--stamp);
	background: var(--stamp-soft);
	border: 1px solid var(--stamp);
	border-radius: 2px;
	padding: 3px 9px;
	text-transform: uppercase;
}
.sdd-code::before { content: "§"; opacity: .7; }

/* ---------- Header ---------- */
.sdd-header {
	background: var(--paper-card);
	border-bottom: 3px double var(--navy);
	position: sticky; top: 0; z-index: 40;
}
.sdd-header-inner {
	display: flex; align-items: center; justify-content: space-between;
	flex-wrap: nowrap;
	padding: 14px 24px; max-width: var(--container); margin: 0 auto; gap: 20px;
}
.sdd-logo {
	display: flex; align-items: baseline; gap: 8px;
	font-family: var(--font-display); font-weight: 700; font-size: 1.32rem;
	color: var(--navy-deep); white-space: nowrap; flex-shrink: 0;
}
.sdd-logo small { font-family: var(--font-mono); font-size: 0.58rem; color: var(--stamp); font-weight: 600; letter-spacing: .06em; white-space: nowrap; }

.sdd-nav {
	display: flex; align-items: center; gap: 22px; font-size: 0.92rem; font-weight: 500;
	flex: 1 1 auto; min-width: 0;
}
.sdd-nav a { color: var(--ink); white-space: nowrap; }

/* Dropdown "Chủ đề" — thay cho việc nhét flat cả 9 link làm vỡ header */
.sdd-dropdown { position: relative; }
.sdd-dropdown-toggle {
	display: flex; align-items: center; gap: 5px;
	background: none; border: 0; font: inherit; color: var(--ink);
	cursor: pointer; padding: 4px 0; white-space: nowrap;
}
.sdd-dropdown-toggle svg { transition: transform .15s ease; }
.sdd-dropdown.open .sdd-dropdown-toggle svg,
.sdd-dropdown:hover .sdd-dropdown-toggle svg { transform: rotate(180deg); }

.sdd-dropdown-menu {
	position: absolute; top: calc(100% + 14px); left: -14px;
	background: var(--paper-card); border: 1px solid var(--line); border-radius: var(--radius);
	box-shadow: 0 14px 32px rgba(20,40,66,.14);
	padding: 8px; min-width: 300px;
	display: grid; grid-template-columns: 1fr 1fr; gap: 2px;
	opacity: 0; visibility: hidden; transform: translateY(6px);
	transition: opacity .15s ease, transform .15s ease, visibility .15s ease;
	z-index: 50;
}
.sdd-dropdown:hover .sdd-dropdown-menu,
.sdd-dropdown:focus-within .sdd-dropdown-menu,
.sdd-dropdown.open .sdd-dropdown-menu { opacity: 1; visibility: visible; transform: translateY(0); }
.sdd-dropdown-menu a {
	display: flex; align-items: center; gap: 8px;
	padding: 8px 10px; border-radius: 4px; font-size: .85rem; font-weight: 500;
	white-space: normal;
}
.sdd-dropdown-menu a:hover { background: var(--line-soft); text-decoration: none; }
.sdd-dropdown-tab {
	font-family: var(--font-mono); font-size: .66rem; font-weight: 600; color: var(--stamp);
	background: var(--stamp-soft); border-radius: 2px; padding: 1px 5px; flex-shrink: 0;
}

.sdd-search-toggle {
	border: 1px solid var(--line); background: var(--paper); border-radius: var(--radius);
	padding: 8px 14px; font-family: var(--font-body); cursor: pointer;
	display: flex; align-items: center; gap: 8px; color: var(--ink-soft);
	flex-shrink: 0; white-space: nowrap;
}

.sdd-nav-toggle {
	display: none; flex-direction: column; justify-content: center; gap: 4px;
	width: 38px; height: 34px; background: none; border: 1px solid var(--line);
	border-radius: 4px; cursor: pointer; flex-shrink: 0; padding: 0;
}
.sdd-nav-toggle span { display: block; height: 2px; width: 20px; margin: 0 auto; background: var(--ink); border-radius: 2px; }

.sdd-mobile-search { display: none; }
.sdd-mobile-search.open {
	display: block; padding: 14px 24px; border-top: 1px solid var(--line); background: var(--paper-card);
}

/* ---------- Responsive header (mobile) ---------- */
@media (max-width: 860px) {
	.sdd-logo { font-size: 1.12rem; }
	.sdd-search-toggle-label { display: none; }
	.sdd-nav-toggle { display: flex; }

	.sdd-nav {
		position: absolute; top: 100%; left: 0; right: 0;
		background: var(--paper-card); border-bottom: 1px solid var(--line);
		flex-direction: column; align-items: stretch; gap: 4px;
		padding: 10px 24px 16px; display: none; z-index: 45;
		box-shadow: 0 14px 24px rgba(20,40,66,.1);
	}
	.sdd-nav.open { display: flex; }
	.sdd-nav > a { padding: 10px 4px; border-bottom: 1px solid var(--line-soft); }

	.sdd-dropdown-toggle { width: 100%; justify-content: space-between; padding: 10px 4px; border-bottom: 1px solid var(--line-soft); }
	.sdd-dropdown-menu {
		position: static; box-shadow: none; border: 0; padding: 4px 0 4px 10px;
		grid-template-columns: 1fr; opacity: 1; visibility: visible; transform: none;
		display: none; min-width: 0;
	}
	.sdd-dropdown.open .sdd-dropdown-menu { display: grid; }
}


/* ---------- Hero / homepage index ---------- */
.sdd-hero {
	background: var(--navy-deep);
	color: #EDEFE6;
	padding: 56px 24px 64px;
	position: relative;
	background-image: radial-gradient(circle at 85% 20%, rgba(168,50,43,0.25), transparent 45%);
}
.sdd-hero-inner { max-width: var(--container); margin: 0 auto; }
.sdd-hero-eyebrow { font-family: var(--font-mono); font-size: .8rem; letter-spacing: .12em; text-transform: uppercase; color: #C9A9A6; }
.sdd-hero h1 { color: #fff; font-size: 2.6rem; max-width: 720px; margin: .3em 0 .4em; }
.sdd-hero p { color: #C4CAD6; max-width: 620px; font-size: 1.05rem; }
.sdd-search-box { margin-top: 28px; max-width: 560px; display: flex; background: #fff; border-radius: var(--radius); overflow: hidden; box-shadow: 0 8px 24px rgba(0,0,0,.25); }
.sdd-search-box input { flex: 1; border: 0; padding: 14px 16px; font-family: var(--font-body); font-size: 1rem; }
.sdd-search-box button { border: 0; background: var(--stamp); color: #fff; padding: 0 22px; font-weight: 600; cursor: pointer; }
.sdd-hero-stats { display: flex; gap: 32px; margin-top: 32px; flex-wrap: wrap; }
.sdd-hero-stats div { font-family: var(--font-mono); }
.sdd-hero-stats .n { font-size: 1.6rem; font-weight: 700; color: #fff; display:block; }
.sdd-hero-stats .l { font-size: .78rem; color: #9CA6BB; text-transform: uppercase; letter-spacing: .06em; }

/* ---------- Topic index grid ("mục lục chủ đề") ---------- */
.sdd-index-section { padding: 56px 24px; }
.sdd-index-head { display:flex; align-items:baseline; justify-content:space-between; margin-bottom: 22px; flex-wrap:wrap; gap:8px; }
.sdd-index-head h2 { border: none; margin: 0; }
.sdd-index-head .count { font-family: var(--font-mono); color: var(--ink-soft); font-size: .85rem; }
.sdd-topic-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; }
@media (max-width: 900px) { .sdd-topic-grid { grid-template-columns: repeat(2,1fr); } }
@media (max-width: 600px) { .sdd-topic-grid { grid-template-columns: 1fr; } }

.sdd-topic-card {
	background: var(--paper-card);
	border: 1px solid var(--line);
	border-left: 4px solid var(--navy);
	border-radius: var(--radius);
	padding: 20px 20px 18px;
	position: relative;
	transition: transform .15s ease, box-shadow .15s ease;
}
.sdd-topic-card:hover { transform: translateY(-2px); box-shadow: 0 10px 24px rgba(20,40,66,.08); text-decoration: none; }
.sdd-topic-card .tab { position: absolute; top: -1px; right: -1px; background: var(--navy); color: #fff; font-family: var(--font-mono); font-size: .68rem; padding: 3px 8px; border-radius: 0 3px 0 6px; letter-spacing: .05em; }
.sdd-topic-card h3 { margin: .1em 0 .35em; font-size: 1.1rem; color: var(--navy-deep); }
.sdd-topic-card p { color: var(--ink-soft); font-size: .9rem; margin-bottom: .6em; }
.sdd-topic-card .meta { font-family: var(--font-mono); font-size: .75rem; color: var(--teal); }

/* ---------- Article list / card ---------- */
.sdd-term-list { list-style: none; margin: 0; padding: 0; border-top: 1px solid var(--line); }
.sdd-term-list li { border-bottom: 1px solid var(--line); }
.sdd-term-list a { display: flex; align-items: center; gap: 14px; padding: 15px 4px; color: var(--ink); }
.sdd-term-list a:hover { background: var(--line-soft); text-decoration:none; }
.sdd-term-list .code { font-family: var(--font-mono); font-size: .74rem; color: var(--stamp); min-width: 76px; }
.sdd-term-list .title { flex:1; font-weight: 500; }
.sdd-term-list .vol { font-family: var(--font-mono); font-size: .74rem; color: var(--ink-soft); }

/* ---------- Article layout ---------- */
.sdd-article-wrap { display: grid; grid-template-columns: 220px minmax(0,1fr) 260px; gap: 40px; padding: 36px 24px 70px; max-width: var(--container); margin: 0 auto; align-items: start; }
@media (max-width: 1100px) { .sdd-article-wrap { grid-template-columns: 1fr; } .sdd-toc, .sdd-aside { display:none; } }

.sdd-breadcrumb { font-size: .82rem; color: var(--ink-soft); margin-bottom: 14px; }
.sdd-breadcrumb a { color: var(--ink-soft); }
.sdd-breadcrumb span { margin: 0 6px; }

.sdd-article-head { border-bottom: 1px dashed var(--line); padding-bottom: 20px; margin-bottom: 24px; }
.sdd-article-head .badges { display:flex; gap: 10px; align-items:center; margin-bottom: 12px; flex-wrap: wrap; }
.sdd-badge-topic { font-size: .74rem; font-weight: 600; color: var(--navy); background: #E7EDF3; padding: 3px 10px; border-radius: 20px; }
.sdd-meta-row { display:flex; gap: 18px; font-size: .82rem; color: var(--ink-soft); flex-wrap:wrap; margin-top: 10px; }
.sdd-meta-row b { color: var(--ink); }

.sdd-toc { position: sticky; top: 90px; font-size: .86rem; }
.sdd-toc h4 { font-family: var(--font-mono); font-size: .72rem; text-transform: uppercase; letter-spacing: .06em; color: var(--ink-soft); margin: 0 0 10px; }
.sdd-toc ol { list-style: none; margin: 0; padding: 0; border-left: 2px solid var(--line); }
.sdd-toc li { margin: 0; }
.sdd-toc a { display:block; padding: 6px 0 6px 14px; color: var(--ink-soft); border-left: 2px solid transparent; margin-left: -2px; }
.sdd-toc a.active, .sdd-toc a:hover { color: var(--navy); border-left-color: var(--stamp); font-weight: 600; text-decoration:none; }
.sdd-toc li.lvl3 a { padding-left: 26px; font-size: .92em; }

.sdd-content { font-size: 1.02rem; }
.sdd-content h2 { scroll-margin-top: 90px; }
.sdd-content h3 { scroll-margin-top: 90px; }
.sdd-content ul, .sdd-content ol { padding-left: 1.3em; }
.sdd-content li { margin-bottom: .4em; }
.sdd-content table { width: 100%; border-collapse: collapse; margin: 1.2em 0; font-size: .93rem; }
.sdd-content th, .sdd-content td { border: 1px solid var(--line); padding: 9px 12px; text-align: left; }
.sdd-content th { background: var(--navy); color: #fff; font-family: var(--font-mono); font-size: .78rem; text-transform: uppercase; letter-spacing: .03em; }
.sdd-content tr:nth-child(even) td { background: var(--line-soft); }

.sdd-callout {
	border: 1px solid var(--line);
	border-left: 4px solid var(--teal);
	background: #EEF6F3;
	border-radius: var(--radius);
	padding: 16px 18px;
	margin: 1.4em 0;
	font-size: .95rem;
}
.sdd-callout.warn { border-left-color: var(--stamp); background: var(--stamp-soft); }
.sdd-callout strong { display:block; margin-bottom:4px; font-family: var(--font-mono); font-size:.78rem; text-transform:uppercase; letter-spacing:.04em; }

.sdd-faq { border-top: 1px dashed var(--line); margin-top: 2em; padding-top: 1em; }
.sdd-faq-item { border-bottom: 1px solid var(--line); }
.sdd-faq-item summary { cursor: pointer; padding: 14px 4px; font-weight: 600; color: var(--navy-deep); list-style: none; display:flex; justify-content:space-between; gap:12px; }
.sdd-faq-item summary::-webkit-details-marker { display:none; }
.sdd-faq-item summary::after { content:"+"; font-family: var(--font-mono); color: var(--stamp); }
.sdd-faq-item[open] summary::after { content:"−"; }
.sdd-faq-item p { padding: 0 4px 16px; color: var(--ink-soft); }

.sdd-aside { position: sticky; top: 90px; }
.sdd-widget { border: 1px solid var(--line); border-radius: var(--radius); padding: 16px; margin-bottom: 18px; background: var(--paper-card); }
.sdd-widget-title, .sdd-widget h3 { font-family: var(--font-mono); text-transform: uppercase; font-size: .74rem; letter-spacing: .06em; color: var(--ink-soft); margin: 0 0 10px; }
.sdd-related-list { list-style: none; margin:0; padding:0; }
.sdd-related-list li { padding: 8px 0; border-bottom: 1px solid var(--line-soft); font-size: .9rem; }
.sdd-related-list a { color: var(--ink); }
.sdd-related-list .code { display:block; font-family: var(--font-mono); font-size: .7rem; color: var(--stamp); }

/* ---------- Footer ---------- */
.sdd-footer { background: var(--navy-deep); color: #B9C1D1; padding: 48px 24px 24px; margin-top: 60px; }
.sdd-footer-inner { max-width: var(--container); margin: 0 auto; display: grid; grid-template-columns: 2fr 1fr 1fr 1fr; gap: 32px; }
@media (max-width: 780px) { .sdd-footer-inner { grid-template-columns: 1fr 1fr; } }
.sdd-footer h4 { color: #fff; font-family: var(--font-mono); font-size: .74rem; text-transform: uppercase; letter-spacing: .06em; margin: 0 0 14px; }
.sdd-footer a { color: #B9C1D1; font-size: .88rem; display:block; margin-bottom: 8px; }
.sdd-footer-bottom { max-width: var(--container); margin: 32px auto 0; padding-top: 20px; border-top: 1px solid rgba(255,255,255,.1); font-size: .78rem; color: #7C8AA3; display:flex; justify-content:space-between; flex-wrap:wrap; gap:8px; }
.sdd-footer-bottom .sdd-code { background: transparent; border-color: #7C8AA3; color: #C9A9A6; }

/* ---------- Search results ---------- */
.sdd-search-summary { padding: 20px 0; color: var(--ink-soft); }

/* ---------- Utility ---------- */
.sdd-skip-link { position:absolute; left:-9999px; top:auto; }
.sdd-skip-link:focus { left: 10px; top: 10px; background:#fff; padding:10px; z-index:100; }
@media (prefers-reduced-motion: reduce) { * { transition: none !important; scroll-behavior: auto !important; } }