/* Tin Học HT — static site stylesheet. Palette: xanh lá đậm (#1f8a70) + navy (#0f3d5c), accent cam CTA (#ff7a30). */
:root {
  --brand: #1f8a70;
  --brand-dark: #0f3d5c;
  --accent: #ff7a30;
  --ink: #1c2733;
  --muted: #56626e;
  --line: #e3e9f0;
  --bg-alt: #f5f8fc;
  --radius: 14px;
}
* { box-sizing: border-box; }
body { margin: 0; font-family: 'Segoe UI', Roboto, Arial, sans-serif; color: var(--ink); line-height: 1.6; }
img { max-width: 100%; display: block; }
a { color: var(--brand-dark); text-decoration: none; }
.container { max-width: 1100px; margin: 0 auto; padding: 0 20px; }

/* Header */
.site-header { position: sticky; top: 0; z-index: 50; background: #fff; border-bottom: 1px solid var(--line); }
.header-inner { display: flex; align-items: center; justify-content: space-between; gap: 20px; padding: 12px 20px; }
.logo { display: flex; align-items: center; gap: 10px; }
.logo-icon { width: 42px; height: 42px; border-radius: 50%; object-fit: cover; border: 1px solid var(--line); }
.logo-text { display: flex; flex-direction: column; line-height: 1.2; }
.logo-text-1 { color: var(--brand-dark); font-weight: 800; }
.logo-text-2 { color: var(--brand); font-weight: 800; }
.logo-text small { color: var(--muted); font-size: .72rem; }

.main-nav .nav-list { list-style: none; display: flex; align-items: center; gap: 15px; margin: 0; padding: 0; flex-wrap: wrap; }
.main-nav a { color: var(--ink); font-weight: 600; font-size: .92rem; padding: 6px 2px; border-bottom: 2px solid transparent; }
.main-nav a:hover, .main-nav a.active { color: var(--brand); border-bottom-color: var(--brand); }

/* Menu 2 cấp */
.main-nav .nav-item { position: relative; }
.main-nav .nav-top { display: inline-flex; align-items: center; gap: 4px; white-space: nowrap; }
.main-nav .caret { font-size: .68rem; color: var(--muted); }
.main-nav .sub-toggle { display: none; background: none; border: 0; font-size: 1rem; color: var(--muted); cursor: pointer; padding: 4px 10px; }
.main-nav .submenu { display: none; list-style: none; margin: 0; padding: 10px; position: absolute; top: 100%; left: -12px;
  background: #fff; border: 1px solid var(--line); border-radius: 12px; box-shadow: 0 16px 40px rgba(15,61,92,.16);
  min-width: 260px; z-index: 60; }
.main-nav .submenu.cols-2 { columns: 2; column-gap: 16px; min-width: 500px; }
.main-nav .submenu.cols-3 { columns: 3; column-gap: 16px; min-width: 700px; }
.main-nav .submenu li { break-inside: avoid; }
.main-nav .submenu a { display: block; padding: 7px 10px; font-weight: 500; font-size: .88rem; border-radius: 8px; border-bottom: 0; white-space: normal; }
.main-nav .submenu a:hover { background: var(--bg-alt); color: var(--brand); border-bottom: 0; }
.main-nav .submenu-all { break-inside: avoid; margin-top: 6px; border-top: 1px solid var(--line); padding-top: 6px; }
.main-nav .submenu-all a { color: var(--brand); font-weight: 700; }
/* cầu nối vô hình để chuột đi từ mục cha xuống submenu không bị mất hover */
.main-nav .nav-item.has-sub::after { content: ""; position: absolute; left: 0; right: 0; top: 100%; height: 12px; }
@media (min-width: 861px) {
  .main-nav .nav-item.has-sub:hover > .submenu,
  .main-nav .nav-item.has-sub:focus-within > .submenu { display: block; }
  .main-nav .submenu.cols-3, .main-nav .submenu.cols-2 { left: auto; right: -12px; }
}
.hotline-btn { background: var(--accent); color: #fff !important; font-weight: 700; padding: 10px 18px; border-radius: 999px; white-space: nowrap; }
.hotline-btn-mobile { display: none; margin-top: 14px; text-align: center; }
.nav-toggle { display: none; flex-direction: column; gap: 5px; background: none; border: 0; cursor: pointer; padding: 8px; position: relative; z-index: 70; }
.nav-toggle span { width: 24px; height: 2px; background: var(--ink); transition: transform .2s ease, opacity .2s ease; }
body.nav-open .nav-toggle span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
body.nav-open .nav-toggle span:nth-child(2) { opacity: 0; }
body.nav-open .nav-toggle span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

.mobile-cta-bar, .float-cta { display: none; }

/* Hero */
.hero { background: linear-gradient(135deg, var(--brand-dark), var(--brand)); color: #fff; padding: 60px 0; }
.hero-inner { display: flex; align-items: center; gap: 36px; }
.hero-text { flex: 1; }
.hero-img { flex-shrink: 0; }
.hero-img img { border-radius: var(--radius); box-shadow: 0 14px 34px rgba(0,0,0,.22); }
.hero h1 { font-size: 2rem; line-height: 1.25; margin: 0 0 6px; color: #fff; }
.hero-sub { font-weight: 700; color: #fff; font-size: 1.1rem; margin: 0 0 14px; }
.hero p { color: #dceee8; font-size: 1.02rem; margin: 0 0 16px; }
.hero-cta { display: flex; gap: 14px; flex-wrap: wrap; margin-top: 18px; }
@media (max-width: 700px) { .hero-inner { flex-direction: column; } }

.btn { display: inline-block; padding: 12px 24px; border-radius: 999px; font-weight: 700; cursor: pointer; }
.btn-primary { background: var(--accent); color: #fff; }
.btn-primary:hover { background: #e8691f; }
.btn-outline { background: transparent; color: #fff; border: 2px solid rgba(255,255,255,.7); }
.btn-outline:hover { background: rgba(255,255,255,.12); }
.btn-lg { font-size: 1.05rem; padding: 14px 32px; }

/* Sections */
.section { padding: 52px 0; }
.section-alt { background: var(--bg-alt); }
.section h2 { font-size: 1.5rem; color: var(--brand-dark); margin: 0 0 24px; }
.section-cta { background: var(--brand-dark); color: #fff; text-align: center; }
.section-cta h2 { color: #fff; }
.section-cta p { color: #cfe3dc; margin-bottom: 22px; }

.grid { display: grid; gap: 24px; }
.grid-2 { grid-template-columns: 1fr 1fr; }
.grid-3 { grid-template-columns: repeat(3, 1fr); }

.check-list { list-style: none; margin: 0; padding: 0; display: flex; flex-direction: column; gap: 12px; }
.check-list li { padding-left: 28px; position: relative; }
.check-list li::before { content: "✓"; position: absolute; left: 0; color: var(--brand); font-weight: 800; }
.check-list-2col { display: grid; grid-template-columns: 1fr 1fr; column-gap: 30px; }

.section p, .section li { color: var(--ink); }
.section .lead { font-size: 1.15rem; font-weight: 700; color: var(--brand-dark); margin-bottom: 6px; }
.section img { border-radius: var(--radius); margin: 20px 0; }
.photo-grid { margin: 20px 0; }
.photo-grid img { width: 100%; height: auto; object-fit: cover; margin: 0; }
.callout { background: var(--bg-alt); border-left: 4px solid var(--accent); border-radius: 8px; padding: 18px 22px; margin: 20px 0; }
.callout p { margin: 6px 0; }
.callout-text { font-weight: 700; color: var(--brand-dark); }

.card { background: #fff; border: 1px solid var(--line); border-radius: var(--radius); padding: 24px; box-shadow: 0 6px 18px rgba(15,61,92,.06); }
.card h3 { margin: 0 0 10px; color: var(--brand-dark); }
.card p { color: var(--muted); font-size: .94rem; }
.card-link { font-weight: 700; color: var(--brand); display: inline-block; margin-top: 10px; }

.price-table-wrap { overflow-x: auto; border: 1px solid var(--line); border-radius: var(--radius); }
.price-table { width: 100%; border-collapse: collapse; }
.price-table th, .price-table td { padding: 12px 16px; text-align: left; border-bottom: 1px solid var(--line); }
.price-table th { background: var(--bg-alt); color: var(--brand-dark); }
.price-table .price { font-weight: 700; color: var(--accent); text-align: right; }
.price-note { color: var(--muted); font-size: .86rem; margin-top: 12px; }

/* Footer */
.site-footer { background: var(--brand-dark); color: #cfe3dc; padding: 48px 0 20px; }
.footer-inner { display: grid; grid-template-columns: 1.5fr 1fr 1fr 1fr; gap: 32px; }
.footer-col h2 { color: #fff; font-size: 1.05rem; margin: 0 0 14px; }
.footer-col p { font-size: .9rem; margin: 0 0 8px; }
.footer-col a { color: #cfe3dc; }
.footer-col ul { list-style: none; margin: 0; padding: 0; display: flex; flex-direction: column; gap: 8px; font-size: .9rem; }
.copyright { text-align: center; color: #9fc2b8; font-size: .82rem; margin: 36px 0 0; }

/* Trang nội dung (breadcrumb, danh mục con, liên quan, CTA) */
.breadcrumb { padding: 14px 0 0; font-size: .84rem; color: var(--muted); }
.breadcrumb ol { list-style: none; display: flex; flex-wrap: wrap; gap: 6px; margin: 0; padding: 0; }
.breadcrumb li + li::before { content: "›"; margin-right: 6px; color: var(--muted); }
.breadcrumb a { color: var(--muted); }
.breadcrumb a:hover { color: var(--brand); }

.page-content { max-width: 900px; }
.page-content h1 { font-size: 1.9rem; line-height: 1.3; margin: 8px 0 18px; }
.page-content h2 { font-size: 1.32rem; margin: 32px 0 12px; color: var(--brand-dark); }
.page-content h3 { font-size: 1.1rem; margin: 24px 0 10px; }
.page-content h4 { font-size: 1rem; margin: 20px 0 8px; }
.page-content p { margin: 0 0 12px; }
.page-content img { border-radius: 10px; margin: 16px 0; border: 1px solid var(--line); }
.page-content > .check-list { margin: 0 0 16px; }

.cta-box { background: var(--bg-alt); border: 1px solid var(--line); border-left: 4px solid var(--accent);
  border-radius: 12px; padding: 18px 20px; margin: 30px 0; }
.cta-box p { margin: 0 0 10px; }
.cta-box p:last-child { margin: 0; display: flex; gap: 12px; flex-wrap: wrap; }

.child-list, .related { margin-top: 38px; padding-top: 24px; border-top: 1px solid var(--line); }
.child-list h2, .related h2 { margin-top: 0; font-size: 1.15rem; }
.card-grid { list-style: none; margin: 0; padding: 0; display: grid; grid-template-columns: repeat(2, 1fr); gap: 14px; }
.card-grid a { display: block; border: 1px solid var(--line); border-radius: 12px; padding: 14px 16px; height: 100%; transition: box-shadow .15s ease, border-color .15s ease; }
.card-grid a:hover { border-color: var(--brand); box-shadow: 0 8px 22px rgba(31,138,112,.12); }
.card-grid strong { display: block; color: var(--brand-dark); margin-bottom: 6px; font-size: .96rem; }
.card-grid span { color: var(--muted); font-size: .84rem; }
.link-list { list-style: none; margin: 0; padding: 0; display: grid; grid-template-columns: repeat(2, 1fr); gap: 8px 20px; }
.link-list a { display: block; padding: 6px 0 6px 16px; position: relative; font-size: .92rem; }
.link-list a::before { content: "›"; position: absolute; left: 0; color: var(--brand); }

/* Trang Bảng giá */
.price-highlight { display: grid; grid-template-columns: repeat(4, 1fr); gap: 12px; margin: 24px 0 32px; }
.price-highlight > div { background: var(--bg-alt); border: 1px solid var(--line); border-radius: 12px;
  padding: 16px 12px; text-align: center; }
.ph-num { display: block; font-size: 1.28rem; font-weight: 800; color: var(--brand); line-height: 1.2; }
.ph-lbl { display: block; font-size: .82rem; color: var(--muted); margin-top: 4px; }

.price-table-wrap { overflow-x: auto; border: 1px solid var(--line); border-radius: 12px; }
.price-table { width: 100%; border-collapse: collapse; font-size: .93rem; background: #fff; }
.price-table thead th { background: var(--brand-dark); color: #fff; text-align: left; padding: 13px 16px;
  font-size: .88rem; letter-spacing: .02em; text-transform: uppercase; white-space: nowrap; }
.price-table tbody tr + tr { border-top: 1px solid var(--line); }
.price-table tbody tr:nth-child(even) { background: #fafcff; }
.price-table th[scope="row"] { text-align: left; padding: 14px 16px; vertical-align: top; width: 200px; }
.pt-anh { width: 92px; height: 68px; object-fit: contain; margin: 0 0 8px; border: 0; background: #fff; }
.pt-hang { display: block; font-weight: 800; color: var(--brand-dark); font-size: 1rem; }
.pt-loai { display: block; font-weight: 500; color: var(--muted); font-size: .84rem; margin-top: 2px; }
.pt-models { padding: 14px 16px; vertical-align: top; }
.pt-models ul { list-style: none; margin: 0; padding: 0; display: grid; grid-template-columns: 1fr 1fr; gap: 2px 18px; }
.pt-models li { font-size: .88rem; color: var(--ink); padding-left: 14px; position: relative; }
.pt-models li::before { content: "·"; position: absolute; left: 4px; color: var(--brand); font-weight: 700; }
.pt-gia { padding: 14px 16px; vertical-align: top; text-align: right; white-space: nowrap; width: 130px; }
.pt-gia strong { display: block; font-size: 1.22rem; color: var(--accent); font-weight: 800; }
.pt-gia small { display: block; color: var(--muted); font-size: .74rem; margin-top: 2px; }

.price-notes { list-style: none; margin: 16px 0 0; padding: 0; }
.price-notes li { position: relative; padding-left: 22px; margin-bottom: 7px; font-size: .9rem; color: var(--muted); }
.price-notes li::before { content: "ⓘ"; position: absolute; left: 0; color: var(--brand); }
.price-commit { margin-top: 34px; }
.price-gallery { margin-top: 38px; }
.gallery-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 14px; margin-top: 14px; }
.gallery-grid a { display: block; border: 1px solid var(--line); border-radius: 10px; overflow: hidden; background: #fff; }
.gallery-grid a:hover { border-color: var(--brand); box-shadow: 0 8px 22px rgba(31,138,112,.14); }
.gallery-grid img { width: 100%; height: 100%; object-fit: contain; margin: 0; border: 0; }
.price-more { margin-top: 34px; padding-top: 22px; border-top: 1px solid var(--line); color: var(--muted); font-size: .93rem; }

/* Dòng dẫn nhẹ sang website cùng hệ thống — đặt cuối bài, cỡ chữ nhỏ, không phô trương */
.cross-hint { margin: 26px 0 0; padding-top: 14px; border-top: 1px solid var(--line);
  font-size: .88rem; color: var(--muted); }
.cross-hint a { color: var(--brand-dark); text-decoration: underline; text-underline-offset: 2px; }

/* Dẫn sang bài hướng dẫn cùng site (gom sức mạnh về một bài chủ lực) */
.inline-guide { margin: 26px 0; padding: 14px 18px; background: var(--bg-alt);
  border-left: 3px solid var(--brand); border-radius: 8px; }
.inline-guide p { margin: 0; font-size: .95rem; }

/* Bảng giá rút gọn nhúng trong bài viết hỏi về giá */
.price-inline { margin: 34px 0; padding: 22px 24px; background: var(--bg-alt); border: 1px solid var(--line); border-radius: 14px; }
.price-inline h2 { margin-top: 0; }
.price-inline .price-table-wrap { background: #fff; }
.price-table-compact th[scope="row"] { width: auto; }
.price-table-compact .pt-gia { width: 150px; }
.price-inline .price-notes { margin-bottom: 16px; }

/* Responsive */
@media (max-width: 860px) {
  .card-grid, .link-list { grid-template-columns: 1fr; }
  .page-content h1 { font-size: 1.5rem; }
  .price-highlight { grid-template-columns: 1fr 1fr; }
  .gallery-grid { grid-template-columns: 1fr 1fr; }
  .pt-models ul { grid-template-columns: 1fr; }
  .price-table th[scope="row"], .pt-gia { width: auto; }
  .price-table { font-size: .88rem; }
  .nav-toggle { display: flex; }
  .main-nav { position: fixed; inset: 0 0 0 30%; background: #fff; padding: 90px 24px 24px; transform: translateX(100%); transition: transform .25s ease; overflow-y: auto; z-index: 60; }
  body.nav-open .main-nav { transform: translateX(0); }
  .main-nav .nav-list { flex-direction: column; align-items: stretch; gap: 0; }
  .main-nav .nav-item { display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between; border-bottom: 1px solid var(--line); }
  .main-nav .nav-item .nav-top { flex: 1; padding: 13px 0; }
  .main-nav .nav-item.has-sub::after { display: none; }
  .main-nav .sub-toggle { display: block; }
  .main-nav .nav-item.open .sub-toggle { transform: rotate(180deg); }
  .main-nav .submenu, .main-nav .submenu.cols-2, .main-nav .submenu.cols-3 { position: static; min-width: 0; columns: 1;
    border: 0; box-shadow: none; padding: 0 0 10px 12px; border-left: 2px solid var(--line); margin: 0 0 8px; width: 100%; }
  .main-nav .nav-item.open > .submenu { display: block; }
  .main-nav .submenu a { padding: 9px 8px; }
  .hotline-btn-mobile { display: block; }
  .hotline-btn-desktop { display: none; }
  .grid-2, .grid-3, .check-list-2col { grid-template-columns: 1fr; }
  .footer-inner { grid-template-columns: 1fr 1fr; }
  .mobile-cta-bar { display: flex; position: fixed; bottom: 0; left: 0; right: 0; z-index: 40; }
  .mobile-cta-bar .mobile-cta { flex: 1; text-align: center; padding: 14px 0; font-weight: 700; color: #fff; }
  .mobile-cta-bar .call { background: var(--accent); }
  .mobile-cta-bar .zalo { background: #0068ff; }
  body { padding-bottom: 54px; }
}
@media (min-width: 861px) {
  .float-cta { display: flex; flex-direction: column; gap: 10px; position: fixed; right: 20px; bottom: 24px; z-index: 40; }
  .float-btn { width: 52px; height: 52px; border-radius: 50%; display: flex; align-items: center; justify-content: center; color: #fff; font-weight: 700; font-size: .8rem; box-shadow: 0 8px 20px rgba(0,0,0,.18); }
  .float-zalo { background: #0068ff; }
  .float-call { background: var(--accent); font-size: 1.1rem; }
}