:root {
  --primary: #F97316;
  --primary-dark: #C2410C;
  --keep: #059669;
  --ink: #1F2937;
  --gray: #6B7280;
  --bg: #ffffff;
  --surface: #F9FAFB;
  --border: #E5E7EB;
}
@media (prefers-color-scheme: dark) {
  :root {
    --ink: #F3F4F6;
    --gray: #9CA3AF;
    --bg: #111827;
    --surface: #1F2937;
    --border: #374151;
  }
}
* { box-sizing: border-box; }
body {
  margin: 0;
  font: 16px/1.65 -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  color: var(--ink);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
}
a { color: var(--primary-dark); }
@media (prefers-color-scheme: dark) { a { color: var(--primary); } }
.wrap { max-width: 1060px; margin: 0 auto; padding: 0 24px; }

/* Thanh điều hướng */
nav {
  position: sticky; top: 0; z-index: 10;
  background: color-mix(in srgb, var(--bg) 88%, transparent);
  backdrop-filter: saturate(180%) blur(12px);
  border-bottom: 1px solid var(--border);
}
nav .wrap { display: flex; align-items: center; gap: 20px; height: 60px; }
.brand { display: flex; align-items: center; gap: 10px; font-weight: 650; text-decoration: none; color: var(--ink); }
.brand img { width: 28px; height: 28px; border-radius: 6px; }
nav .links { margin-left: auto; display: flex; align-items: center; gap: 18px; }
nav a.nav { text-decoration: none; color: var(--gray); font-size: 14px; }
nav a.nav:hover { color: var(--ink); }
.lang { display: flex; border: 1px solid var(--border); border-radius: 999px; overflow: hidden; }
.lang button {
  border: 0; background: transparent; color: var(--gray);
  font: inherit; font-size: 13px; padding: 4px 12px; cursor: pointer;
}
.lang button[aria-pressed="true"] { background: var(--primary); color: #fff; }

/* Hero */
header { padding: 72px 0 40px; text-align: center; }
.badge {
  display: inline-flex; align-items: center; gap: 8px;
  font-size: 13px; color: var(--primary-dark);
  background: color-mix(in srgb, var(--primary) 12%, transparent);
  border-radius: 999px; padding: 6px 14px; margin-bottom: 22px;
}
@media (prefers-color-scheme: dark) { .badge { color: var(--primary); } }
.badge .dot { width: 7px; height: 7px; border-radius: 50%; background: var(--primary); }
h1 { font-size: clamp(34px, 5vw, 52px); line-height: 1.12; margin: 0 0 18px; letter-spacing: -0.02em; }
.lede { font-size: clamp(17px, 2vw, 20px); color: var(--gray); max-width: 640px; margin: 0 auto 30px; }
.cta { display: flex; gap: 12px; justify-content: center; flex-wrap: wrap; }
.btn {
  display: inline-block; text-decoration: none; font-weight: 600; font-size: 15px;
  padding: 12px 24px; border-radius: 10px; border: 1px solid transparent;
}
.btn-primary { background: var(--primary); color: #fff; }
.btn-primary:hover { background: var(--primary-dark); }
.btn-ghost { border-color: var(--border); color: var(--ink); }
.shot { margin: 46px auto 0; max-width: 980px; }
.shot img {
  width: 100%; height: auto; display: block;
  border-radius: 12px; border: 1px solid var(--border);
  box-shadow: 0 20px 50px rgba(0,0,0,.16);
}
.caption { font-size: 13px; color: var(--gray); text-align: center; margin-top: 12px; }

/* Phần nội dung */
section { padding: 64px 0; border-top: 1px solid var(--border); }
h2 { font-size: clamp(24px, 3vw, 32px); margin: 0 0 10px; letter-spacing: -0.01em; }
.sub { color: var(--gray); margin: 0 0 34px; max-width: 640px; }
.grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); gap: 22px; }
.card { background: var(--surface); border: 1px solid var(--border); border-radius: 12px; padding: 22px; }
.card h3 { margin: 0 0 8px; font-size: 17px; display: flex; align-items: center; gap: 9px; }
.card p { margin: 0; color: var(--gray); font-size: 15px; }
.tag { width: 9px; height: 9px; border-radius: 50%; flex: none; }
.tag.sig { background: var(--primary); }
.tag.safe { background: var(--keep); }
.split { display: grid; grid-template-columns: 1fr 1fr; gap: 40px; align-items: center; }
.split img { width: 100%; border-radius: 12px; border: 1px solid var(--border); }
@media (max-width: 760px) { .split { grid-template-columns: 1fr; } }
ul.plain { padding-left: 20px; color: var(--gray); }
ul.plain li { margin-bottom: 8px; }
.note {
  border-left: 3px solid var(--primary); padding: 4px 0 4px 16px;
  color: var(--gray); font-size: 15px; margin: 24px 0 0;
}
footer { border-top: 1px solid var(--border); padding: 34px 0 60px; color: var(--gray); font-size: 14px; }
footer .wrap { display: flex; gap: 20px; flex-wrap: wrap; align-items: center; }
footer a { color: var(--gray); }
footer .right { margin-left: auto; }
[data-lang] { display: none; }
html[lang="vi"] [data-lang="vi"], html[lang="en"] [data-lang="en"] { display: revert; }