/* cpnao.com — dùng chung cho mọi trang trong landing/ */
:root {
  --bg: #ffffff; --fg: #18181b; --muted: #5f5f68; --card: #f6f6f7; --border: #e4e4e7;
  --primary: #15803d; --primary-soft: #dcfce7; --primary-fg: #ffffff;
  --warn-bg: #fef3c7; --warn-fg: #78350f; --bad: #b91c1c; --bad-soft: #fee2e2;
  --code: #f1f5f9;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0b0b0c; --fg: #f4f4f5; --muted: #a1a1aa; --card: #161618; --border: #2a2a2e;
    --primary: #22c55e; --primary-soft: #0f2a1a; --primary-fg: #052e16;
    --warn-bg: #3a2a07; --warn-fg: #fde68a; --bad: #f87171; --bad-soft: #3b1212;
    --code: #1c1c20;
  }
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; font-family: "Be Vietnam Pro", system-ui, sans-serif; background: var(--bg); color: var(--fg); line-height: 1.65; }
a { color: var(--primary); }
img { max-width: 100%; }
.wrap { max-width: 1080px; margin: 0 auto; padding: 0 16px; }
.narrow { max-width: 820px; }

/* Thanh trên cùng */
.topbar { position: sticky; top: 0; z-index: 10; background: color-mix(in srgb, var(--bg) 92%, transparent); backdrop-filter: blur(8px); border-bottom: 1px solid var(--border); }
.topbar .wrap { display: flex; align-items: center; gap: 16px; padding-top: 10px; padding-bottom: 10px; flex-wrap: wrap; }
.brand { display: flex; align-items: center; gap: 10px; line-height: 1.15; text-decoration: none; color: var(--fg); margin-right: auto; }
.brand span { display: flex; flex-direction: column; }
.brand img { border-radius: 8px; flex: none; }
.brand b { color: var(--primary); font-size: 1.1rem; }
.brand small { color: var(--muted); font-size: .75rem; }
.menu { display: flex; gap: 4px; flex-wrap: wrap; }
.menu a { color: var(--fg); text-decoration: none; padding: 6px 10px; border-radius: 8px; font-size: .92rem; }
.menu a:hover, .menu a[aria-current="page"] { background: var(--card); color: var(--primary); }
@media (max-width: 640px) {
  .menu { order: 3; width: 100%; overflow-x: auto; flex-wrap: nowrap; }
  .menu a { white-space: nowrap; }
}

.btn { display: inline-block; background: var(--primary); color: var(--primary-fg); padding: 10px 18px; border-radius: 10px; text-decoration: none; font-weight: 600; border: 1px solid var(--primary); }
.btn.ghost { background: transparent; color: var(--fg); border-color: var(--border); }
.btn.sm { padding: 6px 14px; font-size: .9rem; }

/* Phần đầu trang */
.hero { padding: 56px 0 32px; text-align: center; }
.eyebrow { display: inline-block; font-size: .8rem; font-weight: 600; letter-spacing: .04em; color: var(--primary); background: var(--primary-soft); padding: 4px 12px; border-radius: 999px; margin-bottom: 14px; }
.hero h1 { font-size: clamp(1.8rem, 4.4vw, 2.9rem); line-height: 1.2; margin: 0 0 14px; }
.hero p.lead { color: var(--muted); max-width: 700px; margin: 0 auto 26px; font-size: 1.08rem; }
.hero .actions { display: flex; gap: 10px; justify-content: center; flex-wrap: wrap; }
.page-head { padding: 40px 0 8px; }
.page-head h1 { font-size: clamp(1.6rem, 3.6vw, 2.3rem); margin: 0 0 8px; line-height: 1.25; }
.page-head p { color: var(--muted); margin: 0; max-width: 720px; }

section { padding: 30px 0; }
section h2 { font-size: 1.5rem; margin: 0 0 6px; line-height: 1.3; }
section .sub { color: var(--muted); margin: 0 0 20px; }
h3 { line-height: 1.35; }

.grid { display: grid; gap: 12px; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); }
.grid.two { grid-template-columns: repeat(auto-fit, minmax(320px, 1fr)); }
.card { background: var(--card); border: 1px solid var(--border); border-radius: 14px; padding: 18px; }
.card h3 { margin: 0 0 6px; font-size: 1.02rem; }
.card p { margin: 0; color: var(--muted); font-size: .95rem; }
.card ul { margin: 6px 0 0; padding-left: 18px; color: var(--muted); font-size: .95rem; }
.tag { display: inline-block; font-size: .72rem; font-weight: 700; letter-spacing: .05em; color: var(--primary); margin-bottom: 4px; }

/* Khối "là gì / không là gì" */
.versus { display: grid; gap: 12px; grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); }
.versus .card.yes { border-color: var(--primary); }
.versus .card.no { border-color: var(--bad); }
.versus h3 .mark { display: inline-block; width: 1.4em; }
.versus .yes h3 { color: var(--primary); }
.versus .no h3 { color: var(--bad); }
.versus li { margin: 4px 0; }

/* Sơ đồ luồng */
.flow { list-style: none; padding: 0; margin: 0; display: grid; gap: 10px; grid-template-columns: repeat(6, 1fr); counter-reset: step; }
.flow li { position: relative; background: var(--card); border: 1px solid var(--border); border-radius: 14px; padding: 16px 14px 14px; counter-increment: step; }
.flow li::before { content: counter(step); display: inline-grid; place-items: center; width: 28px; height: 28px; border-radius: 50%; background: var(--primary); color: var(--primary-fg); font-weight: 700; font-size: .9rem; margin-bottom: 8px; }
.flow li:not(:last-child)::after { content: "→"; position: absolute; right: -10px; top: 50%; transform: translate(50%, -50%); color: var(--muted); font-weight: 700; }
.flow h3 { margin: 0 0 4px; font-size: .98rem; }
.flow p { margin: 0; color: var(--muted); font-size: .88rem; }
.flow .who { display: inline-block; margin-top: 8px; font-size: .72rem; font-weight: 700; padding: 2px 8px; border-radius: 6px; background: var(--bg); border: 1px solid var(--border); color: var(--muted); }
@media (max-width: 960px) {
  .flow { grid-template-columns: 1fr; }
  .flow li { display: grid; grid-template-columns: 36px 1fr; column-gap: 10px; }
  .flow li::before { grid-row: span 3; margin: 0; }
  .flow li:not(:last-child)::after { content: "↓"; right: auto; left: 28px; top: auto; bottom: -10px; transform: translate(-50%, 50%); }
  .flow .who { justify-self: start; }
}

/* Hạng */
.tiers { display: grid; gap: 8px; grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); }
.tier { display: flex; gap: 12px; align-items: flex-start; background: var(--card); border: 1px solid var(--border); border-radius: 12px; padding: 12px 14px; }
.tier .badge { flex: none; min-width: 44px; text-align: center; padding: 4px 8px; border-radius: 8px; font-weight: 700; }
.tier b { display: block; font-size: .95rem; }
.tier span.d { color: var(--muted); font-size: .9rem; }
.t-a { background: #16a34a; color: #fff; } .t-b { background: #2563eb; color: #fff; }
.t-c { background: #facc15; color: #422006; } .t-n { background: #e2e8f0; color: #1e293b; }
.t-d { background: #71717a; color: #fff; } .t-r { background: #dc2626; color: #fff; }

.shots { display: grid; gap: 16px; grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); }
.shots figure { margin: 0; }
.shots img { width: 100%; border-radius: 12px; border: 1px solid var(--border); display: block; }
.shots figcaption { color: var(--muted); font-size: .88rem; margin-top: 6px; }

.note { background: var(--warn-bg); color: var(--warn-fg); border-radius: 12px; padding: 14px 16px; font-size: .95rem; }
.callout { border-left: 4px solid var(--primary); background: var(--primary-soft); padding: 12px 16px; border-radius: 0 12px 12px 0; margin: 16px 0; }
.callout p { margin: 0; }
.cta { text-align: center; background: var(--card); border: 1px solid var(--border); border-radius: 16px; padding: 32px 16px; }
.cta h2 { margin-bottom: 8px; }
.cta p { color: var(--muted); margin: 0 auto 18px; max-width: 560px; }

/* Bảng & mã */
.table-wrap { overflow-x: auto; margin: 12px 0; border: 1px solid var(--border); border-radius: 12px; }
table { border-collapse: collapse; width: 100%; font-size: .93rem; }
th, td { text-align: left; padding: 8px 12px; border-bottom: 1px solid var(--border); vertical-align: top; }
th { background: var(--card); font-weight: 600; }
tr:last-child td { border-bottom: 0; }
td.num, th.num { text-align: right; white-space: nowrap; }
code, pre { font-family: ui-monospace, "Cascadia Mono", Consolas, monospace; font-size: .88em; }
code { background: var(--code); padding: 1px 5px; border-radius: 5px; }
pre { background: var(--code); padding: 12px 14px; border-radius: 10px; overflow-x: auto; line-height: 1.5; }

/* Trang tài liệu: mục lục bên trái + nội dung */
.doc { display: grid; grid-template-columns: 230px 1fr; gap: 32px; padding: 24px 0 40px; }
.toc { position: sticky; top: 76px; align-self: start; max-height: calc(100vh - 96px); overflow-y: auto; font-size: .9rem; }
.toc b { display: block; margin-bottom: 6px; }
.toc ol { list-style: none; padding: 0; margin: 0; }
.toc a { display: block; padding: 4px 8px; border-radius: 6px; color: var(--muted); text-decoration: none; }
.toc a:hover { background: var(--card); color: var(--primary); }
.doc article { min-width: 0; }
.doc article h2 { font-size: 1.4rem; margin: 36px 0 8px; padding-top: 8px; border-top: 1px solid var(--border); scroll-margin-top: 80px; }
.doc article h2:first-child { margin-top: 0; border-top: 0; padding-top: 0; }
.doc article h3 { font-size: 1.08rem; margin: 22px 0 6px; }
.doc article .num-badge { color: var(--primary); font-weight: 700; margin-right: 6px; }
@media (max-width: 860px) {
  .doc { grid-template-columns: 1fr; gap: 8px; }
  .toc { position: static; max-height: none; background: var(--card); border: 1px solid var(--border); border-radius: 12px; padding: 12px; }
  .toc ol { columns: 2; column-gap: 12px; }
}

.steps { counter-reset: s; list-style: none; padding: 0; margin: 0; }
.steps > li { counter-increment: s; position: relative; padding: 0 0 18px 44px; }
.steps > li::before { content: counter(s); position: absolute; left: 0; top: 0; width: 30px; height: 30px; border-radius: 50%; background: var(--primary-soft); color: var(--primary); font-weight: 700; display: grid; place-items: center; font-size: .9rem; }
.steps > li b.t { display: block; }
.steps > li p { margin: 2px 0 0; color: var(--muted); }

footer { color: var(--muted); font-size: .85rem; padding: 28px 0; border-top: 1px solid var(--border); margin-top: 24px; }
footer .wrap { display: flex; flex-wrap: wrap; gap: 8px 20px; justify-content: space-between; }
footer a { color: inherit; }