/* Trang /tai-app — chép từ Worker cũ, tách khỏi HTML (CSP không inline) */
:root { color-scheme: light dark; }
*:focus-visible { outline: 3px solid #2563eb; outline-offset: 2px; }
body { font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", system-ui, sans-serif; max-width: 760px; margin: 0 auto; padding: 24px 20px 80px; color: #111827; line-height: 1.6; background: #fff; }
header { display: flex; align-items: center; justify-content: space-between; padding: 12px 0 28px; border-bottom: 1px solid #d1d5db; margin-bottom: 32px; }
.brand { font-weight: 800; font-size: 20px; color: #1e40af; text-decoration: none; display: flex; align-items: center; gap: 8px; }
header nav.site-nav { display: flex; align-items: center; gap: 4px; flex-wrap: wrap; flex: 1; }
header nav.site-nav a { color: #374151; text-decoration: none; font-weight: 600; font-size: 15px; padding: 6px 12px; border-radius: 6px; white-space: nowrap; }
header nav.site-nav a:hover { background: #eff6ff; color: #1e40af; }
@media (max-width: 560px) { header { flex-wrap: wrap; gap: 10px; } header nav.site-nav { order: 3; flex-basis: 100%; gap: 2px; } header nav.site-nav a { font-size: 14px; padding: 5px 10px; } }
h1 { font-size: 30px; font-weight: 800; margin: 0 0 8px; }
.sub { color: #4b5563; margin: 0 0 28px; }
.card { border: 1px solid #e5e7eb; border-radius: 16px; padding: 22px; margin-bottom: 16px; display: flex; align-items: center; gap: 16px; }
.card.primary { border-color: #1e40af; background: #eff6ff; }
.ic { flex-shrink: 0; width: 48px; height: 48px; border-radius: 12px; background: #1e40af; color: #fff; display: flex; align-items: center; justify-content: center; }
.ic-sm { width: 34px; height: 34px; border-radius: 9px; }
.ic-sky { background: #0ea5e9; }
.ic-green { background: #16a34a; }
.ic-gray { background: #6b7280; }
.card .body { flex: 1; }
.card h2 { font-size: 18px; font-weight: 700; margin: 0 0 3px; }
.card p { font-size: 13.5px; color: #4b5563; margin: 0; }
.btn { flex-shrink: 0; display: inline-block; padding: 11px 20px; border-radius: 10px; background: #1e40af; color: #fff; text-decoration: none; font-weight: 600; font-size: 14px; white-space: nowrap; }
.btn:hover { background: #1e3a8a; }
.btn.ghost { background: transparent; color: #1e40af; border: 1px solid #1e40af; }
.btn-green { background: #16a34a; }
.push-right { margin-left: auto; }
.note { font-size: 12.5px; color: #78350f; background: #fffbeb; border: 1px solid #fde68a; border-radius: 10px; padding: 12px 14px; margin-top: 20px; line-height: 1.6; }
footer { margin-top: 48px; padding-top: 18px; border-top: 1px solid #d1d5db; text-align: center; font-size: 13px; color: #6b7280; }
footer a { color: #1e40af; }
@media (max-width: 520px) { .card { flex-wrap: wrap; } .btn { width: 100%; text-align: center; } }
@media (max-width: 520px) { header .btn { width: auto; } }