/* Lane D (A9, A10) — trang đăng ký học / mua nội dung. Độc lập với host/style.css, ưu tiên điện thoại. */
:root {
  --co-bg: #f4f7fc; --co-card: #fff; --co-ink: #16213a; --co-ink-2: #3d4a5c; --co-muted: #5f6b80; --co-line: #dfe6f1;
  --co-blue: #2f5fe0; --co-blue-soft: #e3ebfd; --co-ok: #138a4f; --co-ok-soft: #e3f6ec; --co-warn: #9a6200; --co-warn-soft: #fdf1d8; --co-bad: #c62f2f; --co-on-blue: #fff;
}
* { box-sizing: border-box; }
body.co-page { margin: 0; background: var(--co-bg); color: var(--co-ink); font: 400 16px/1.5 "Be Vietnam Pro", "Segoe UI", system-ui, -apple-system, Roboto, Arial, sans-serif; }
.co-top { display: flex; justify-content: space-between; align-items: center; gap: 12px; padding: 12px 16px; background: var(--co-card); border-bottom: 1px solid var(--co-line); }
.co-brand { font-weight: 800; color: var(--co-blue); text-decoration: none; }
.co-main { max-width: 720px; margin: 0 auto; padding: 20px 16px 64px; display: flex; flex-direction: column; gap: 16px; }
.co-card { background: var(--co-card); border: 1px solid var(--co-line); border-radius: 14px; padding: 20px; display: flex; flex-direction: column; gap: 12px; }
.co-card h1 { margin: 0; font-size: 24px; line-height: 1.25; overflow-wrap: anywhere; }
.co-card h2 { margin: 0; font-size: 18px; }
.co-card p { margin: 0; }
.co-muted { color: var(--co-muted); font-size: 14px; }
.co-eyebrow { font-size: 12px; font-weight: 700; letter-spacing: .06em; text-transform: uppercase; color: var(--co-blue); }
.co-price { font-size: 26px; font-weight: 800; }
.co-desc { white-space: pre-wrap; overflow-wrap: anywhere; color: var(--co-ink-2); }
.co-facts { list-style: none; margin: 0; padding: 0; display: grid; gap: 6px; }
.co-facts li { display: flex; justify-content: space-between; gap: 12px; border-bottom: 1px dashed var(--co-line); padding-bottom: 6px; }
.co-facts li span:first-child { color: var(--co-muted); }
.co-qr { display: flex; justify-content: center; padding: 12px; background: #fff; border-radius: 10px; }
.co-code { font-family: ui-monospace, Consolas, monospace; letter-spacing: 0.04em; overflow-wrap: anywhere; }
.co-summary { background: var(--co-blue-soft); border-radius: 10px; padding: 12px 14px; font-size: 15px; }
.co-warn { background: var(--co-warn-soft); border: 1px solid var(--co-warn); border-radius: 10px; padding: 12px 14px; display: flex; flex-direction: column; gap: 10px; }
.co-ok { background: var(--co-ok-soft); border-radius: 10px; padding: 14px; color: var(--co-ink); }
.co-err { color: var(--co-bad); font-size: 15px; }
.co-check { display: flex; gap: 10px; align-items: flex-start; cursor: pointer; }
.co-check input { width: 20px; height: 20px; margin: 2px 0 0; flex: none; }
.co-actions { display: flex; flex-wrap: wrap; gap: 10px; }
.co-btn { display: inline-flex; align-items: center; justify-content: center; min-height: 48px; padding: 10px 18px; border-radius: 12px; border: 1px solid var(--co-line); background: var(--co-card); color: var(--co-ink); font: 600 16px/1.2 inherit; text-decoration: none; cursor: pointer; }
.co-btn--primary { background: var(--co-blue); border-color: var(--co-blue); color: var(--co-on-blue); }
.co-btn[disabled] { opacity: .6; cursor: wait; }
.co-btn:focus-visible, .co-check input:focus-visible { outline: 3px solid var(--co-blue); outline-offset: 2px; }
.co-list { list-style: none; margin: 0; padding: 0; display: grid; gap: 10px; }
.co-list li { border: 1px solid var(--co-line); border-radius: 10px; padding: 12px; display: flex; flex-wrap: wrap; justify-content: space-between; gap: 8px; align-items: center; }
@media (max-width: 480px) { .co-actions .co-btn { flex: 1 1 100%; } .co-card { padding: 16px; } }
.co-author { display: flex; gap: 14px; align-items: center; }
.co-avatar { width: 56px; height: 56px; border-radius: 50%; display: grid; place-items: center; flex: none; background: var(--co-blue-soft); color: var(--co-blue); font-weight: 800; font-size: 22px; }
.co-list li > div { flex: 1 1 220px; min-width: 0; display: flex; flex-direction: column; gap: 4px; }
.co-list li strong { overflow-wrap: anywhere; }
.co-title { margin: 0; font-size: 24px; }