/* Trang cong khai (SEO) - khong can JavaScript */
:root { --ink: #1A2035; --ink-2: #464F6E; --muted: #747C98; --line: #DFE3EE; --paper: #F5F6FA; --card: #fff; --tim: #5B3FD6; --tim-soft: #EEEAFD; --la: #138A5A; --do: #D3263A; --code: #1B2034; --code-ink: #E6E9F5; color-scheme: light dark; }
@media (prefers-color-scheme: dark) { :root { --ink: #E8F0EB; --ink-2: #B4C3BC; --muted: #82958D; --line: #2A3E39; --paper: #14211E; --card: #1A2B27; --tim: #A895F0; --tim-soft: rgba(168,149,240,.15); } }
* { box-sizing: border-box; }
body { margin: 0; font-family: "Be Vietnam Pro", system-ui, -apple-system, "Segoe UI", Roboto, sans-serif; color: var(--ink); background: var(--paper); line-height: 1.65; font-size: 16px; }
a { color: var(--tim); }
.pub-top { display: flex; align-items: center; justify-content: space-between; gap: 12px; padding: 12px 20px; border-bottom: 1px solid var(--line); background: var(--card); position: sticky; top: 0; flex-wrap: wrap; }
.pub-brand { display: flex; gap: 8px; align-items: center; font-weight: 800; color: var(--ink); text-decoration: none; }
.pub-brand .mark { background: var(--tim); color: #fff; border-radius: 8px; padding: 2px 7px; font-size: 14px; }
.pub-top nav { display: flex; gap: 14px; align-items: center; flex-wrap: wrap; }
.pub-top nav a { text-decoration: none; font-weight: 600; }
.btn { display: inline-block; padding: 9px 16px; border-radius: 10px; border: 1px solid var(--line); background: var(--card); color: var(--ink); text-decoration: none; font-weight: 600; }
.btn-primary { background: var(--tim); border-color: var(--tim); color: #fff; }
.pub-main { max-width: 860px; margin: 0 auto; padding: 24px 16px 48px; }
h1 { font-size: clamp(26px, 5vw, 34px); line-height: 1.25; margin: 6px 0 10px; }
h2 { font-size: 21px; margin: 28px 0 10px; }
.lead { font-size: 18px; color: var(--ink-2); }
.muted { color: var(--muted); }
.kicker { color: var(--tim); font-weight: 700; font-size: 14px; margin: 0; }
.crumbs { font-size: 14px; color: var(--muted); }
pre { background: var(--code); color: var(--code-ink); padding: 12px 16px; border-radius: 10px; overflow-x: auto; font-family: "JetBrains Mono", ui-monospace, Menlo, Consolas, monospace; font-size: 14px; }
pre.good { border-left: 4px solid var(--la); }
.mistake { border-bottom: 1px solid var(--line); padding: 8px 0; }
.mistake pre:first-child { border-left: 4px solid var(--do); }
.cta { margin: 28px 0; padding: 18px; border-radius: 14px; background: var(--tim-soft); }
.cta p { margin: 6px 0 12px; }
.pub-list li { margin-bottom: 12px; }
.pro { background: #F5B300; color: #2A1700; font-size: 12px; font-weight: 800; padding: 1px 7px; border-radius: 6px; }
.plans { display: grid; grid-template-columns: repeat(auto-fit, minmax(190px, 1fr)); gap: 14px; margin: 18px 0; }
.plan { background: var(--card); border: 1px solid var(--line); border-radius: 14px; padding: 16px; }
.plan h2 { margin: 0; font-size: 18px; }
.plan .price { font-size: 26px; font-weight: 800; margin: 6px 0; }
.plan ul { padding-left: 18px; font-size: 14.5px; }
.pager { display: flex; justify-content: space-between; gap: 12px; margin-top: 30px; padding-top: 16px; border-top: 1px solid var(--line); flex-wrap: wrap; }
.legal h2 { font-size: 18px; }
.pub-foot { border-top: 1px solid var(--line); padding: 20px 16px 32px; text-align: center; font-size: 14px; }
.pub-foot nav { display: flex; gap: 14px; justify-content: center; flex-wrap: wrap; margin: 8px 0; }

.pub-brand .logo { height: 40px; max-width: 64px; object-fit: contain; }
.pub-brand .logo.only { max-width: 180px; }

/* Python Lab 4.0.5 — shared public pricing and policy visual system */
:root { color-scheme: light; --ink:#172033; --ink-2:#526078; --muted:#788399; --line:#e4e9f1; --paper:#f6f8fc; --card:#fff; --tim:#5b3fd6; --tim-soft:#f0edff; --la:#16845d; --do:#d3263a; --code:#1b2034; --code-ink:#e6e9f5; }
body { background:var(--paper); color:var(--ink); }
.pub-top { min-height:68px; padding:12px max(20px,calc((100vw - 1160px)/2)); box-shadow:0 3px 18px rgba(23,32,51,.045); z-index:20; }
.pub-brand { gap:10px; font-size:16px; letter-spacing:-.02em; }
.pub-top nav { gap:8px; }
.pub-top nav a:not(.btn) { padding:9px 12px; border-radius:10px; color:var(--ink-2); }
.pub-top nav a:not(.btn):hover { background:var(--tim-soft); color:var(--tim); }
.pub-top nav .btn { padding:10px 17px; border-radius:11px; background:var(--tim); color:#fff; border-color:var(--tim); }
.pub-main { max-width:1120px; padding:44px 22px 64px; }
.pub-main > h1 { max-width:850px; margin:0 auto 12px; text-align:center; font-size:clamp(30px,4.5vw,44px); line-height:1.13; letter-spacing:-.045em; }
.pub-main > .lead { max-width:690px; margin:0 auto 30px; text-align:center; font-size:17px; line-height:1.7; }
.plans { grid-template-columns:repeat(auto-fit,minmax(min(100%,235px),1fr)); gap:18px; margin:28px 0 24px; align-items:stretch; }
.plan { position:relative; display:flex; flex-direction:column; min-width:0; padding:24px; border:1px solid var(--line); border-radius:19px; background:var(--card); box-shadow:0 10px 28px rgba(23,32,51,.055); transition:transform .18s ease,box-shadow .18s ease,border-color .18s ease; }
.plan:hover { transform:translateY(-3px); box-shadow:0 16px 34px rgba(23,32,51,.09); border-color:#cfc7fa; }
.plan h2 { margin:0; font-size:18px; font-weight:750; letter-spacing:-.02em; }
.plan .price { margin:9px 0 0; color:var(--ink); font-size:clamp(28px,3vw,34px); line-height:1.2; letter-spacing:-.045em; font-weight:850; overflow-wrap:anywhere; }
.plan .muted { margin:3px 0 0; font-size:13px; }
.plan ul { flex:1; margin:18px 0 22px; padding:16px 0 0 20px; border-top:1px solid var(--line); color:var(--ink-2); font-size:14px; line-height:1.7; }
.plan li { padding-left:2px; margin:0 0 7px; }
.plan .btn { width:100%; text-align:center; padding:11px 16px; border-radius:11px; }
.plan .btn-primary { color:#fff; background:var(--tim); border-color:var(--tim); }
.pub-main > p.muted { max-width:850px; margin:24px auto 0; padding:16px 18px; border:1px solid var(--line); border-radius:14px; background:#fff; line-height:1.7; font-size:14px; }
.pub-main > p.muted a { font-weight:650; }
.legal { max-width:850px; margin:0 auto; padding:clamp(22px,4vw,42px); border:1px solid var(--line); border-radius:20px; background:#fff; box-shadow:0 10px 28px rgba(23,32,51,.045); }
.legal h1 { margin:8px 0 22px; font-size:clamp(28px,4vw,38px); letter-spacing:-.04em; }
.legal h2 { margin:26px 0 8px; font-size:18px; letter-spacing:-.02em; }
.legal p,.legal li { color:var(--ink-2); line-height:1.8; }
.legal ul,.legal ol { padding-left:22px; }
.crumbs { max-width:850px; margin:0 auto 12px; }
.pub-foot { padding:26px 18px 36px; background:#fff; }
.pub-foot nav a { color:var(--ink-2); text-decoration:none; }
.pub-foot nav a:hover { color:var(--tim); }
@media(max-width:640px) {
 .pub-top { padding:10px 14px; }
 .pub-top nav { width:100%; justify-content:space-between; gap:4px; }
 .pub-top nav a:not(.btn) { padding:8px 7px; font-size:13px; }
 .pub-main { padding:30px 14px 44px; }
 .pub-main > .lead { font-size:15px; margin-bottom:22px; }
 .plans { grid-template-columns:1fr; gap:13px; margin-top:20px; }
 .plan { padding:20px; }
 .legal { padding:22px 18px; border-radius:16px; }
}
@media(prefers-reduced-motion:reduce) { .plan { transition:none; } .plan:hover { transform:none; } }

/* Python Lab 4.0.6 — one consistent visual language for all public pages */
:root { color-scheme: light; }
body { background:#f6f8fc; color:#172033; }
.pub-main { width:min(100%,1160px); }
.pub-main > section { margin:28px 0 0; padding:24px; border:1px solid #e4e9f1; border-radius:18px; background:#fff; box-shadow:0 8px 26px rgba(23,32,51,.045); }
.pub-main > section h2 { margin:0 0 7px; font-size:clamp(19px,2vw,22px); letter-spacing:-.025em; }
.pub-main > section > .muted { margin:0 0 16px; }
.pub-list { display:grid; grid-template-columns:repeat(2,minmax(0,1fr)); gap:12px; padding:0; margin:0; list-style:none; counter-reset:lesson; }
.pub-list li { position:relative; min-width:0; margin:0; padding:17px 18px 16px 54px; border:1px solid #e8ecf3; border-radius:14px; background:#fbfcff; counter-increment:lesson; transition:border-color .16s ease,transform .16s ease,box-shadow .16s ease; }
.pub-list li::before { content:counter(lesson,decimal-leading-zero); position:absolute; left:16px; top:17px; display:grid; place-items:center; width:27px; height:27px; border-radius:9px; background:#f0edff; color:#5b3fd6; font-size:11px; font-weight:800; }
.pub-list li:hover { transform:translateY(-2px); border-color:#cfc7fa; box-shadow:0 10px 22px rgba(23,32,51,.06); }
.pub-list li > a { color:#172033; text-decoration:none; font-weight:750; line-height:1.45; }
.pub-list li > a:hover { color:#5b3fd6; }
.pub-list li > .muted { display:inline-block; margin-top:5px; font-size:13.5px; line-height:1.6; }
.pub-main > p.muted { border-color:#e4e9f1; background:#fff; }
.pub-main article { max-width:850px; margin:0 auto; padding:clamp(22px,4vw,40px); border:1px solid #e4e9f1; border-radius:20px; background:#fff; box-shadow:0 8px 26px rgba(23,32,51,.045); }
.pub-main article > h1 { text-align:left; margin:8px 0 10px; }
.pub-main article > h2 { margin-top:28px; font-size:19px; }
.pub-main article > p, .pub-main article > li { color:#526078; line-height:1.8; }
.pub-main article ul,.pub-main article ol { padding-left:22px; }
.pub-main .cta { border:1px solid #e3defd; background:#f5f2ff; }
.pub-main .pager { max-width:850px; margin-left:auto; margin-right:auto; }
.pub-main .pager a { max-width:48%; padding:12px 15px; border:1px solid #e4e9f1; border-radius:12px; background:#fff; text-decoration:none; font-weight:650; }
.pub-main .pager a:hover { border-color:#cfc7fa; background:#f8f6ff; }
.pub-main > h1 + .lead { margin-bottom:24px; }
.pub-foot { border-top:1px solid #e4e9f1; }
@media(max-width:720px) {
 .pub-main { padding:28px 14px 44px; }
 .pub-main > section { padding:17px; border-radius:15px; }
 .pub-list { grid-template-columns:1fr; gap:9px; }
 .pub-list li { padding:14px 14px 14px 50px; }
 .pub-list li::before { left:13px; top:14px; }
 .pub-main article { padding:21px 17px; border-radius:16px; }
 .pub-main .pager a { max-width:100%; }
}
@media(prefers-reduced-motion:reduce) { .pub-list li { transition:none; } .pub-list li:hover { transform:none; } }