/* =====================================================================
   BLAKLETTERPRESS — XƯỞNG IN LETTERPRESS THỦ CÔNG TẠI HÀ NỘI
   BÀI TẬP 4: XÂY DỰNG CSS RESPONSIVE & LAYOUT SÁNG TẠO
   ===================================================================== */

/* 1. GOOGLE FONTS IMPORT */
@import url('https://fonts.googleapis.com/css2?family=Playfair+Display:ital,wght@0,500;0,600;0,700;0,800;1,400;1,600&family=Plus+Jakarta+Sans:wght@300;400;500;600;700&display=swap');

/* 2. CSS VARIABLES / DESIGN TOKENS */
:root {
	/* Palette màu thủ công nghệ thuật & mực in cao cấp */
	--color-bg-page: #fbf9f5;
	--color-bg-card: #ffffff;
	--color-bg-warm: #f6f1e8;
	--color-bg-dark: #1f1b18;
	--color-bg-darker: #151210;

	--color-ink-primary: #211c18;
	--color-ink-secondary: #584f45;
	--color-ink-muted: #82786d;
	--color-ink-light: #f5efe6;

	/* Màu điểm nhấn: Terracotta / Đồng thau / Giấy nung */
	--color-accent: #b45309;
	--color-accent-hover: #92400e;
	--color-accent-soft: rgba(180, 83, 9, 0.1);
	--color-gold: #c9933e;

	--color-border: #e7dfd3;
	--color-border-focus: #b45309;

	/* Typography */
	--font-serif: 'Playfair Display', Georgia, 'Times New Roman', serif;
	--font-sans: 'Plus Jakarta Sans', system-ui, -apple-system, sans-serif;

	/* Bóng & Bo góc */
	--radius-sm: 8px;
	--radius-md: 14px;
	--radius-lg: 20px;
	--radius-full: 9999px;

	--shadow-subtle: 0 2px 8px rgba(33, 28, 24, 0.04);
	--shadow-card: 0 6px 20px rgba(33, 28, 24, 0.06);
	--shadow-hover: 0 14px 32px rgba(33, 28, 24, 0.12);
	--shadow-pop: 0 8px 24px rgba(180, 83, 9, 0.18);

	/* Tối ưu hiệu ứng */
	--transition-smooth: all 0.3s cubic-bezier(0.16, 1, 0.3, 1);
	--header-height: 74px;
}

/* 3. RESET & BASE STYLES */
*,
*::before,
*::after {
	margin: 0;
	padding: 0;
	box-sizing: border-box;
}

html {
	scroll-behavior: smooth;
	scroll-padding-top: calc(var(--header-height) + 20px);
}

body {
	font-family: var(--font-sans);
	font-size: 16px;
	line-height: 1.65;
	color: var(--color-ink-primary);
	background-color: var(--color-bg-page);
	background-image: 
		radial-gradient(at 0% 0%, rgba(201, 147, 62, 0.04) 0px, transparent 50%),
		radial-gradient(at 100% 100%, rgba(180, 83, 9, 0.03) 0px, transparent 50%);
	background-attachment: fixed;
	min-height: 100vh;
	display: flex;
	flex-direction: column;
	-webkit-font-smoothing: antialiased;
	-moz-osx-font-smoothing: grayscale;
}

img {
	max-width: 100%;
	height: auto;
	display: block;
}

a {
	color: inherit;
	text-decoration: none;
	transition: var(--transition-smooth);
}

ul {
	list-style: none;
}

/* 4. HEADER & NAVIGATION */
.site-header {
	position: sticky;
	top: 0;
	z-index: 1000;
	background: rgba(27, 23, 20, 0.95);
	backdrop-filter: blur(12px);
	-webkit-backdrop-filter: blur(12px);
	border-bottom: 2px solid var(--color-gold);
	box-shadow: 0 4px 20px rgba(0, 0, 0, 0.15);
	padding: 14px 32px;
	display: flex;
	align-items: center;
	justify-content: space-between;
	gap: 24px;
	flex-wrap: wrap;
}

.site-name {
	font-family: var(--font-serif);
	font-size: 1.85rem;
	font-weight: 800;
	letter-spacing: 0.04em;
	color: #fff;
	text-transform: uppercase;
	display: inline-flex;
	align-items: center;
	gap: 8px;
	background: linear-gradient(135deg, #ffffff 40%, var(--color-gold) 100%);
	-webkit-background-clip: text;
	-webkit-text-fill-color: transparent;
	transition: var(--transition-smooth);
}

.site-name:hover {
	transform: scale(1.02);
	filter: brightness(1.15);
}

.tagline {
	font-family: var(--font-serif);
	font-style: italic;
	font-size: 0.88rem;
	color: #c7beaf;
	letter-spacing: 0.02em;
	padding-left: 14px;
	border-left: 1px solid rgba(255, 255, 255, 0.2);
	margin-right: auto;
}

.main-nav ul {
	display: flex;
	align-items: center;
	gap: 8px;
}

.main-nav a {
	display: inline-block;
	color: #d8cfc4;
	font-size: 0.95rem;
	font-weight: 500;
	padding: 8px 16px;
	border-radius: var(--radius-sm);
	position: relative;
	transition: var(--transition-smooth);
}

.main-nav a::after {
	content: '';
	position: absolute;
	left: 50%;
	bottom: 2px;
	width: 0;
	height: 2px;
	background: var(--color-gold);
	transition: all 0.25s ease;
	transform: translateX(-50%);
	border-radius: 2px;
}

.main-nav a:hover {
	color: #ffffff;
	background: rgba(255, 255, 255, 0.06);
}

.main-nav a:hover::after {
	width: 60%;
}

/* 5. MAIN LAYOUT (PAGE CONTAINER & SIDEBAR) */
.layout {
	max-width: 1240px;
	width: 100%;
	margin: 0 auto;
	padding: 44px 24px;
	display: grid;
	grid-template-columns: minmax(0, 1fr) 340px;
	gap: 48px;
	align-items: start;
	flex: 1;
}

main {
	display: flex;
	flex-direction: column;
	gap: 56px;
}

/* 6. GENERAL SECTION / ARTICLE HEADINGS */
article h1,
section h2,
aside h2 {
	font-family: var(--font-serif);
	color: var(--color-ink-primary);
	line-height: 1.25;
}

article h1 {
	font-size: 2.5rem;
	font-weight: 700;
	margin-bottom: 24px;
	position: relative;
	display: inline-block;
}

article h1::after {
	content: '';
	position: absolute;
	left: 0;
	bottom: -8px;
	width: 64px;
	height: 4px;
	background: linear-gradient(90deg, var(--color-accent), var(--color-gold));
	border-radius: 2px;
}

section h2 {
	font-size: 1.95rem;
	font-weight: 700;
	margin-bottom: 26px;
	position: relative;
	padding-left: 18px;
}

section h2::before {
	content: '';
	position: absolute;
	left: 0;
	top: 15%;
	bottom: 15%;
	width: 4px;
	background: var(--color-accent);
	border-radius: 2px;
}

/* 7. GIỚI THIỆU ARTICLE */
#gioi-thieu {
	background: var(--color-bg-card);
	border: 1px solid var(--color-border);
	border-radius: var(--radius-lg);
	padding: 38px 40px;
	box-shadow: var(--shadow-card);
	transition: var(--transition-smooth);
}

#gioi-thieu figure {
	margin: 28px 0;
	border-radius: var(--radius-md);
	overflow: hidden;
	border: 1px solid var(--color-border);
	box-shadow: var(--shadow-subtle);
	background: #fff;
}

#gioi-thieu figure img {
	width: 100%;
	height: auto;
	max-height: 480px;
	object-fit: cover;
	transition: transform 0.6s cubic-bezier(0.16, 1, 0.3, 1);
}

#gioi-thieu figure:hover img {
	transform: scale(1.025);
}

#gioi-thieu figcaption {
	padding: 12px 20px;
	font-size: 0.9rem;
	font-style: italic;
	color: var(--color-ink-muted);
	background: var(--color-bg-warm);
	border-top: 1px solid var(--color-border);
	display: flex;
	align-items: center;
	gap: 8px;
}

#gioi-thieu figcaption::before {
	content: '📷';
	font-style: normal;
	font-size: 0.85rem;
}

#gioi-thieu p {
	font-size: 1.075rem;
	color: var(--color-ink-secondary);
	line-height: 1.8;
	margin-bottom: 16px;
}

#gioi-thieu p:first-of-type {
	font-size: 1.15rem;
	color: var(--color-ink-primary);
	font-weight: 450;
}

#gioi-thieu p:last-of-type {
	margin-bottom: 0;
}

#gioi-thieu strong {
	color: var(--color-accent);
	font-weight: 600;
}

/* 8. GIÁ TRỊ CỐT LÕI SECTION */
.value-list {
	display: grid;
	grid-template-columns: repeat(3, 1fr);
	gap: 24px;
}

.value-card {
	background: var(--color-bg-card);
	border: 1px solid var(--color-border);
	border-radius: var(--radius-md);
	padding: 30px 24px;
	box-shadow: var(--shadow-card);
	transition: var(--transition-smooth);
	position: relative;
	overflow: hidden;
	display: flex;
	flex-direction: column;
}

.value-card::before {
	content: '';
	position: absolute;
	top: 0;
	left: 0;
	right: 0;
	height: 4px;
	background: linear-gradient(90deg, var(--color-accent), var(--color-gold));
	opacity: 0.8;
	transition: var(--transition-smooth);
}

.value-card:hover {
	transform: translateY(-8px);
	box-shadow: var(--shadow-pop);
	border-color: rgba(180, 83, 9, 0.35);
}

.value-card:hover::before {
	height: 6px;
	opacity: 1;
}

.value-card h3 {
	font-family: var(--font-serif);
	font-size: 1.35rem;
	color: var(--color-ink-primary);
	margin-bottom: 12px;
	display: flex;
	align-items: center;
	gap: 8px;
}

.value-card:nth-child(1) h3::before { content: '✋'; font-size: 1.1rem; }
.value-card:nth-child(2) h3::before { content: '🌱'; font-size: 1.1rem; }
.value-card:nth-child(3) h3::before { content: '✨'; font-size: 1.1rem; }

.value-card p {
	font-size: 0.95rem;
	color: var(--color-ink-secondary);
	line-height: 1.6;
}

/* 9. ĐỘI NGŨ SECTION */
.team-list {
	display: grid;
	grid-template-columns: repeat(3, 1fr);
	gap: 24px;
}

.member {
	background: var(--color-bg-card);
	border: 1px solid var(--color-border);
	border-radius: var(--radius-md);
	padding: 32px 20px;
	text-align: center;
	box-shadow: var(--shadow-card);
	transition: var(--transition-smooth);
	display: flex;
	flex-direction: column;
	align-items: center;
}

.member:hover {
	transform: translateY(-6px);
	box-shadow: var(--shadow-hover);
	border-color: rgba(180, 83, 9, 0.3);
}

.member img {
	width: 128px;
	height: 128px;
	border-radius: var(--radius-full);
	object-fit: cover;
	margin-bottom: 18px;
	border: 4px solid var(--color-bg-warm);
	box-shadow: 0 4px 14px rgba(33, 28, 24, 0.1);
	transition: var(--transition-smooth);
}

.member:hover img {
	transform: scale(1.08);
	border-color: var(--color-accent);
	box-shadow: 0 8px 20px rgba(180, 83, 9, 0.25);
}

.member h3 {
	font-family: var(--font-serif);
	font-size: 1.3rem;
	color: var(--color-ink-primary);
	margin-bottom: 6px;
}

.member p {
	font-size: 0.9rem;
	color: var(--color-accent);
	font-weight: 500;
	letter-spacing: 0.01em;
}

/* 10. LIÊN HỆ SECTION & FORM */
#lien-he {
	background: var(--color-bg-card);
	border: 1px solid var(--color-border);
	border-radius: var(--radius-lg);
	padding: 38px 40px;
	box-shadow: var(--shadow-card);
}

.contact-form {
	max-width: 640px;
	margin-top: 10px;
}

.contact-form p {
	margin-bottom: 20px;
}

.contact-form label {
	font-size: 0.88rem;
	font-weight: 700;
	text-transform: uppercase;
	letter-spacing: 0.05em;
	color: var(--color-ink-secondary);
	margin-bottom: 6px;
	display: inline-block;
}

.contact-form input[type="text"],
.contact-form input[type="email"],
.contact-form textarea {
	width: 100%;
	padding: 13px 18px;
	font-family: var(--font-sans);
	font-size: 1rem;
	color: var(--color-ink-primary);
	background: #fbf9f6;
	border: 1.5px solid var(--color-border);
	border-radius: var(--radius-sm);
	transition: var(--transition-smooth);
	margin-top: 4px;
}

.contact-form textarea {
	resize: vertical;
	min-height: 110px;
}

.contact-form input:focus,
.contact-form textarea:focus {
	outline: none;
	border-color: var(--color-accent);
	background: #ffffff;
	box-shadow: 0 0 0 4px rgba(180, 83, 9, 0.12);
}

.contact-form button[type="submit"] {
	background: linear-gradient(135deg, var(--color-bg-dark) 0%, #2e2621 100%);
	color: #fff;
	border: none;
	padding: 15px 36px;
	font-family: var(--font-sans);
	font-size: 1rem;
	font-weight: 600;
	letter-spacing: 0.03em;
	border-radius: var(--radius-sm);
	cursor: pointer;
	box-shadow: 0 4px 14px rgba(0, 0, 0, 0.15);
	transition: var(--transition-smooth);
	display: inline-flex;
	align-items: center;
	justify-content: center;
	gap: 8px;
}

.contact-form button[type="submit"]:hover {
	background: linear-gradient(135deg, var(--color-accent) 0%, var(--color-accent-hover) 100%);
	transform: translateY(-2px);
	box-shadow: 0 8px 22px rgba(180, 83, 9, 0.35);
}

.contact-form button[type="submit"]:active {
	transform: translateY(0);
}

/* 11. SIDEBAR */
.sidebar {
	position: sticky;
	top: calc(var(--header-height) + 24px);
	background: var(--color-bg-card);
	border: 1px solid var(--color-border);
	border-radius: var(--radius-md);
	padding: 30px 24px;
	box-shadow: var(--shadow-card);
	transition: var(--transition-smooth);
}

.sidebar h2 {
	font-family: var(--font-serif);
	font-size: 1.35rem;
	font-weight: 700;
	color: var(--color-ink-primary);
	padding-bottom: 14px;
	margin-bottom: 20px;
	border-bottom: 2px solid var(--color-bg-warm);
	position: relative;
}

.sidebar h2::after {
	content: '';
	position: absolute;
	left: 0;
	bottom: -2px;
	width: 40px;
	height: 2px;
	background: var(--color-gold);
}

.sidebar .recent {
	display: flex;
	flex-direction: column;
	gap: 14px;
	margin-bottom: 26px;
}

.sidebar .recent li {
	position: relative;
	padding-left: 20px;
}

.sidebar .recent li::before {
	content: '›';
	position: absolute;
	left: 4px;
	top: -2px;
	font-size: 1.25rem;
	font-weight: 700;
	color: var(--color-accent);
	transition: var(--transition-smooth);
}

.sidebar .recent a {
	color: var(--color-ink-primary);
	font-size: 0.95rem;
	font-weight: 500;
	line-height: 1.45;
	display: inline-block;
}

.sidebar .recent li:hover::before {
	transform: translateX(4px);
}

.sidebar .recent a:hover {
	color: var(--color-accent);
}

.sidebar p {
	font-size: 0.92rem;
	color: var(--color-ink-muted);
	padding-top: 20px;
	border-top: 1px dashed var(--color-border);
	line-height: 1.5;
}

.sidebar a[href*="facebook"] {
	display: inline-flex;
	align-items: center;
	gap: 6px;
	color: #1877f2;
	font-weight: 600;
	background: #ebf3ff;
	padding: 5px 12px;
	border-radius: var(--radius-sm);
	margin-top: 6px;
	transition: var(--transition-smooth);
}

.sidebar a[href*="facebook"]:hover {
	background: #1877f2;
	color: #ffffff;
	transform: translateY(-2px);
	box-shadow: 0 4px 10px rgba(24, 119, 242, 0.25);
}

/* 12. FOOTER */
.site-footer {
	background: var(--color-bg-darker);
	color: var(--color-ink-light);
	border-top: 4px solid var(--color-gold);
	padding: 60px 24px 28px;
	margin-top: 40px;
}

.footer-cols {
	max-width: 1240px;
	margin: 0 auto;
	display: grid;
	grid-template-columns: repeat(4, 1fr);
	gap: 36px;
	padding-bottom: 44px;
	border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.footer-cols li {
	display: flex;
	flex-direction: column;
	gap: 12px;
}

.footer-cols h3 {
	font-family: var(--font-serif);
	font-size: 1.25rem;
	font-weight: 600;
	color: #ffffff;
	letter-spacing: 0.02em;
	position: relative;
	padding-bottom: 8px;
}

.footer-cols h3::after {
	content: '';
	position: absolute;
	left: 0;
	bottom: 0;
	width: 28px;
	height: 2px;
	background: var(--color-accent);
}

.footer-cols p {
	font-size: 0.92rem;
	color: #aba195;
	line-height: 1.7;
}

.copyright {
	max-width: 1240px;
	margin: 28px auto 0;
	text-align: center;
	color: #7b7267;
	font-size: 0.88rem;
}

.copyright small {
	font-size: 100%;
}

/* 13. RESPONSIVE DESIGN (MEDIA QUERIES) */

/* Màn hình Tablet lớn / Laptop nhỏ (<= 1024px) */
@media (max-width: 1024px) {
	.layout {
		grid-template-columns: minmax(0, 1fr) 300px;
		gap: 32px;
		padding: 32px 20px;
	}

	.footer-cols {
		grid-template-columns: repeat(2, 1fr);
		gap: 32px;
	}
}

/* Màn hình Tablet (<= 860px) */
@media (max-width: 860px) {
	.site-header {
		padding: 16px 20px;
	}

	.tagline {
		display: none; /* Rút gọn trên tablet để thanh điều hướng thông thoáng */
	}

	.layout {
		grid-template-columns: 1fr; /* Chuyển thành layout 1 cột */
		gap: 40px;
	}

	.sidebar {
		position: static; /* Hủy sticky khi ở dạng 1 cột */
	}

	#gioi-thieu,
	#lien-he {
		padding: 30px 24px;
	}

	.value-list {
		grid-template-columns: repeat(2, 1fr);
	}
	.value-card:last-child {
		grid-column: span 2;
	}
}

/* Màn hình Mobile (<= 640px) */
@media (max-width: 640px) {
	.site-header {
		flex-direction: column;
		align-items: center;
		text-align: center;
		padding: 14px 16px;
		gap: 12px;
	}

	.site-name {
		font-size: 1.6rem;
	}

	.main-nav ul {
		flex-wrap: wrap;
		justify-content: center;
		gap: 4px;
	}

	.main-nav a {
		padding: 6px 10px;
		font-size: 0.88rem;
	}

	.layout {
		padding: 24px 14px;
		gap: 32px;
	}

	main {
		gap: 40px;
	}

	article h1 {
		font-size: 2rem;
	}

	section h2 {
		font-size: 1.6rem;
	}

	#gioi-thieu,
	#lien-he {
		padding: 24px 18px;
		border-radius: var(--radius-md);
	}

	.value-list {
		grid-template-columns: 1fr;
		gap: 16px;
	}

	.value-card:last-child {
		grid-column: span 1;
	}

	.team-list {
		grid-template-columns: 1fr;
		gap: 16px;
	}

	.contact-form button[type="submit"] {
		width: 100%;
	}

	.footer-cols {
		grid-template-columns: 1fr;
		gap: 24px;
		padding-bottom: 28px;
	}

	.site-footer {
		padding: 40px 16px 20px;
	}
}