*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
	--bg: #0B0F19;
	--card: #121826;
	--border: #1E293B;
	--accent: #00F0FF;
	--green: #00FF85;
	--slate-100: #f1f5f9;
	--slate-300: #cbd5e1;
	--slate-400: #94a3b8;
	--slate-500: #64748b;
	--slate-600: #475569;
	--slate-700: #334155;
	--slate-800: #1e293b;
	--slate-900: #0f172a;
}

html { scroll-behavior: smooth; }

body {
	font-family: 'Inter', system-ui, sans-serif;
	background: var(--bg);
	color: var(--slate-300);
	line-height: 1.5;
	-webkit-font-smoothing: antialiased;
}

a { color: inherit; text-decoration: none; }
img { max-width: 100%; display: block; }

.container { max-width: 72rem; margin: 0 auto; padding: 0 1.5rem; }
.text-center { text-align: center; }
.text-white { color: #fff; }
.text-accent { color: var(--accent); }
.mb-4 { margin-bottom: 1rem; }
.mb-8 { margin-bottom: 2rem; }
.mb-12 { margin-bottom: 3rem; }
.mb-14 { margin-bottom: 3.5rem; }
.mt-2 { margin-top: 0.5rem; }
.max-w-2xl { max-width: 42rem; }
.mx-auto { margin-left: auto; margin-right: auto; }

/* ===== NAV ===== */
.nav {
	position: fixed; top: 0; left: 0; right: 0; z-index: 50; height: 4rem;
	background: rgba(11, 15, 25, 0.88); backdrop-filter: blur(12px);
	border-bottom: 1px solid var(--border);
}
.nav-inner {
	max-width: 72rem; margin: 0 auto; padding: 0 1.5rem; height: 100%;
	display: flex; align-items: center; justify-content: space-between;
}
.nav-logo-img { height: 28px; width: auto; }
.nav-links {
	display: none; align-items: center; gap: 1.75rem;
	font-size: 0.875rem; font-weight: 500; color: var(--slate-400);
}
.nav-links a:hover { color: #fff; }
.nav-links a.active { color: var(--accent); }
.nav-cta {
	display: none; background: var(--accent); color: #000;
	font-size: 0.75rem; font-weight: 700; text-transform: uppercase;
	letter-spacing: 0.08em; padding: 0.6rem 1.2rem; border-radius: 9999px;
}
.nav-cta:hover { background: #fff; }
@media (min-width: 768px) {
	.nav-links { display: flex; }
	.nav-cta { display: inline-flex; }
}
.nav-toggle {
	display: flex; flex-direction: column; justify-content: center; gap: 5px;
	width: 2.25rem; height: 2.25rem; background: transparent; border: none;
	cursor: pointer; padding: 0.25rem; z-index: 60;
}
.nav-toggle-bar {
	display: block; width: 100%; height: 2px; background: #fff; border-radius: 2px;
	transition: transform 0.25s ease, opacity 0.25s ease;
}
.nav-toggle.active .nav-toggle-bar:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav-toggle.active .nav-toggle-bar:nth-child(2) { opacity: 0; }
.nav-toggle.active .nav-toggle-bar:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }
@media (min-width: 768px) { .nav-toggle { display: none; } }
.nav-mobile {
	display: none; position: absolute; top: 4rem; left: 0; right: 0;
	background: rgba(11, 15, 25, 0.97); backdrop-filter: blur(16px);
	border-bottom: 1px solid var(--border); padding: 1.25rem 1.5rem 1.75rem;
	flex-direction: column; gap: 0.35rem; z-index: 49;
}
.nav-mobile.open { display: flex; }
.nav-mobile a {
	display: block; padding: 0.85rem 0.5rem; font-size: 0.95rem;
	font-weight: 500; color: var(--slate-300); border-radius: 0.5rem;
}
.nav-mobile a:hover,
.nav-mobile a.active { background: rgba(0, 240, 255, 0.08); color: #fff; }
.nav-mobile-cta {
	margin-top: 0.75rem; text-align: center;
	background: var(--accent) !important; color: #000 !important;
	font-weight: 700 !important; text-transform: uppercase; letter-spacing: 0.06em;
	font-size: 0.8rem !important; padding: 0.9rem 1rem !important; border-radius: 9999px !important;
}
.nav-mobile-cta:hover { background: #fff !important; }

/* ===== PAGE HERO ===== */
.page-hero {
	position: relative; padding: 8rem 1.5rem 3.5rem; overflow: hidden; text-align: center;
}
.hero-bg {
	position: absolute; inset: 0;
	background: radial-gradient(ellipse at top, var(--slate-900), var(--bg)); z-index: 0;
}
.hero-grid {
	position: absolute; inset: 0;
	background-image:
		linear-gradient(to right, rgba(30,41,59,0.08) 1px, transparent 1px),
		linear-gradient(to bottom, rgba(30,41,59,0.08) 1px, transparent 1px);
	background-size: 4rem 4rem; z-index: 1; pointer-events: none;
}
.hero-content { position: relative; z-index: 2; margin: 0 auto; }
.badge {
	display: inline-block; font-size: 0.6875rem; font-weight: 600;
	text-transform: uppercase; letter-spacing: 0.12em; color: var(--accent);
	background: rgba(0, 240, 255, 0.1); padding: 0.35rem 0.85rem;
	border-radius: 9999px; margin-bottom: 1.25rem;
}
.page-hero-title {
	font-size: clamp(1.85rem, 4.5vw, 2.75rem); font-weight: 900; color: #fff;
	letter-spacing: -0.03em; margin-bottom: 1rem; text-transform: uppercase;
}
.page-hero-desc {
	font-size: 1rem; font-weight: 400; color: var(--slate-400);
	line-height: 1.65; max-width: 36rem; margin: 0 auto;
}

/* ===== SECTION ===== */
.section { padding: 4.5rem 0; }
.section-border { border-top: 1px solid var(--border); }
.section-border-y { border-top: 1px solid var(--border); border-bottom: 1px solid var(--border); }
.section-muted { background: rgba(2, 6, 23, 0.45); }
.section-label-muted {
	font-size: 0.75rem; font-family: ui-monospace, monospace;
	text-transform: uppercase; color: var(--slate-500); margin-bottom: 0.5rem; display: block;
}
.section-title {
	font-size: clamp(1.4rem, 3.2vw, 1.85rem); font-weight: 800; color: #fff;
	margin-bottom: 1rem; text-transform: uppercase; letter-spacing: -0.02em;
}
.section-desc {
	font-size: 0.9375rem; color: var(--slate-400); max-width: 36rem; margin: 0 auto;
}
.body-text {
	font-size: 0.875rem; color: var(--slate-400); line-height: 1.7; margin-bottom: 0.85rem;
}

/* ===== LAYOUT ===== */
.two-col { display: grid; gap: 2.5rem; align-items: center; }
@media (min-width: 1024px) {
	.two-col { grid-template-columns: 5fr 7fr; }
}
.grid-4 { display: grid; gap: 0.85rem; grid-template-columns: repeat(2, 1fr); }
@media (min-width: 768px) { .grid-4 { grid-template-columns: repeat(4, 1fr); } }
.grid-3 { display: grid; gap: 1.15rem; }
@media (min-width: 768px) { .grid-3 { grid-template-columns: repeat(3, 1fr); } }
.grid-2 { display: grid; gap: 1rem; }
@media (min-width: 640px) { .grid-2 { grid-template-columns: repeat(2, 1fr); } }
.next-grid { max-width: 40rem; margin: 0 auto; }

/* ===== SOURCE BOX ===== */
.source-box {
	margin-top: 1rem;
	padding: 1.15rem 1.25rem;
	background: rgba(18, 24, 38, 0.5);
	border: 1px solid var(--border);
	border-radius: 0.75rem;
	text-align: center;
}
.source-caption {
	display: block;
	font-size: 0.625rem;
	font-family: ui-monospace, monospace;
	text-transform: uppercase;
	color: var(--slate-500);
	margin-bottom: 0.5rem;
}
.source-entities {
	font-size: 0.75rem;
	font-family: ui-monospace, monospace;
	font-weight: 700;
	text-transform: uppercase;
	color: #fff;
	line-height: 1.5;
}
.source-arrow {
	display: block;
	color: var(--accent);
	font-size: 1rem;
	margin: 0.5rem 0 0.35rem;
}
.source-result {
	font-size: 0.8125rem;
	font-family: ui-monospace, monospace;
	font-weight: 800;
	text-transform: uppercase;
	color: var(--accent);
}

/* ===== MEDIA BOX ===== */
.media-box {
	background: rgba(18, 24, 38, 0.5);
	border: 1px solid var(--border);
	border-radius: 1rem;
	padding: 1rem;
}
.media-inner {
	aspect-ratio: 16 / 9;
	background: var(--bg);
	border: 1px solid var(--border);
	border-radius: 0.75rem;
	display: flex;
	align-items: center;
	justify-content: center;
	position: relative;
	overflow: hidden;
}
.media-grid-bg {
	position: absolute; inset: 0; opacity: 0.1;
	background-image: radial-gradient(var(--accent) 1px, transparent 1px);
	background-size: 20px 20px;
}
.media-label {
	position: relative; z-index: 1;
	font-size: 0.6875rem; font-family: ui-monospace, monospace;
	text-transform: uppercase; letter-spacing: 0.08em; color: var(--slate-500);
	text-align: center; padding: 0 1.25rem; line-height: 1.6;
}

/* ===== TYPE CHIP ===== */
.type-chip {
	padding: 0.9rem 0.75rem;
	background: rgba(18, 24, 38, 0.35);
	border: 1px solid var(--border);
	border-radius: 0.5rem;
	font-size: 0.6875rem;
	font-family: ui-monospace, monospace;
	font-weight: 700;
	text-transform: uppercase;
	letter-spacing: 0.05em;
	color: var(--slate-300);
	text-align: center;
}
.type-chip-green {
	background: rgba(0, 255, 133, 0.08);
	border-color: rgba(0, 255, 133, 0.3);
	color: var(--green);
}

/* ===== FLOW HORIZONTAL ===== */
.flow-horizontal {
	display: flex;
	flex-wrap: wrap;
	align-items: center;
	justify-content: flex-start;
	gap: 0.4rem 0.35rem;
	background: var(--card);
	border: 1px solid var(--border);
	border-radius: 0.65rem;
	padding: 0.9rem 1rem;
	margin-bottom: 1rem;
}
.flow-center {
	justify-content: center;
	max-width: 48rem;
	margin-left: auto;
	margin-right: auto;
}
.flow-step {
	display: inline-flex;
	align-items: center;
	font-family: ui-monospace, monospace;
	font-size: 0.65rem;
	font-weight: 600;
	letter-spacing: 0.04em;
	color: var(--accent);
	background: rgba(0, 240, 255, 0.07);
	border: 1px solid rgba(0, 240, 255, 0.18);
	padding: 0.35rem 0.65rem;
	border-radius: 0.4rem;
	white-space: nowrap;
	line-height: 1.3;
}
.flow-arrow {
	font-size: 0.75rem;
	color: var(--slate-500);
	font-weight: 500;
	flex-shrink: 0;
	user-select: none;
}

/* ===== PURPOSE CARD ===== */
.purpose-card {
	padding: 1.35rem 1.25rem;
	background: rgba(18, 24, 38, 0.4);
	border: 1px solid var(--border);
	border-radius: 0.75rem;
	text-align: center;
}
.purpose-tag {
	display: inline-block;
	font-size: 0.6875rem;
	font-weight: 700;
	text-transform: uppercase;
	letter-spacing: 0.1em;
	color: var(--accent);
	margin-bottom: 0.65rem;
}
.purpose-text {
	font-size: 0.8125rem;
	color: var(--slate-400);
	line-height: 1.55;
}

.note-center {
	max-width: 36rem;
	margin: 1.75rem auto 0;
	font-size: 0.875rem;
	color: var(--slate-400);
	line-height: 1.65;
}

/* ===== CARD ===== */
.card {
	display: block;
	background: var(--card);
	border: 1px solid var(--border);
	border-radius: 1rem;
	padding: 1.35rem 1.5rem;
	transition: border-color 0.2s, box-shadow 0.2s;
}
.card:hover {
	border-color: rgba(0, 240, 255, 0.4);
	box-shadow: 0 0 20px rgba(0, 240, 255, 0.06);
}
.card-title {
	font-size: 0.75rem;
	font-weight: 700;
	text-transform: uppercase;
	letter-spacing: 0.1em;
	color: var(--accent);
	margin-bottom: 0.5rem;
}
.card-text {
	font-size: 0.8125rem;
	color: var(--slate-400);
	line-height: 1.55;
}

/* ===== FOOTER (giữ — footer.php dùng chung) ===== */
.footer { border-top: 1px solid var(--border); padding: 3rem 0; }
.footer-inner { max-width: 72rem; margin: 0 auto; padding: 0 1.5rem; }
.footer-top {
	display: flex; flex-direction: column; gap: 2rem; margin-bottom: 2.5rem;
}
@media (min-width: 768px) {
	.footer-top { flex-direction: row; justify-content: space-between; }
}
.footer-brand { font-size: 1.35rem; font-weight: 900; color: #fff; margin-bottom: 0.4rem; }
.footer-tagline { font-size: 0.8125rem; color: var(--slate-500); }
.footer-links {
	display: flex; flex-wrap: wrap; gap: 1.5rem; font-size: 0.875rem; color: var(--slate-400);
}
.footer-links a:hover { color: #fff; }
.footer-bottom {
	display: flex; flex-direction: column; gap: 1rem; align-items: center;
	padding-top: 1.75rem; border-top: 1px solid var(--border);
	font-size: 0.8125rem; color: var(--slate-500);
}
@media (min-width: 640px) {
	.footer-bottom { flex-direction: row; justify-content: space-between; }
}
.footer-social { display: flex; gap: 1.25rem; font-size: 1.1rem; }
.footer-social a:hover { color: var(--accent); }