/* Lucy English: tokens and base type. The only file allowed to contain colour values. */

:root {
  --paper: #ffffff;
  --ink: #1b1b1b;
  --muted: #6a6a6a;
  --rule: #dcdcdc;
  --blue: #1a3e9c;
  --blue-weak: #eef2fb;
  --red: #b3261e;
  --green: #1b6e3c;
  --mark: #fff2a8;

  --sans: -apple-system, "Segoe UI", Roboto, Arial, sans-serif;
  --serif: Charter, "Iowan Old Style", Georgia, serif;
  --gutter: 24px;
  color-scheme: light;
}

*, *::before, *::after { box-sizing: border-box; }

html { -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font: 16px/1.5 var(--sans);
}

h1, h2, h3, p, ul, ol, dl, dd, figure { margin: 0; }
h1 { font-size: 28px; line-height: 34px; font-weight: 600; }
h2 { font-size: 20px; line-height: 28px; font-weight: 600; }
h3 { font-size: 16px; line-height: 24px; font-weight: 700; }
ul, ol { padding-left: 24px; }

a { color: var(--blue); text-underline-offset: 2px; transition: color 120ms; }
a:hover { color: var(--ink); }

button, input, select, textarea { font: inherit; color: inherit; }
button { cursor: pointer; }
button:disabled { cursor: default; }

:focus-visible { outline: 2px solid var(--blue); outline-offset: 2px; }
/* Tiêu đề chỉ nhận focus từ bộ định tuyến (cho trình đọc màn hình), không vẽ khung. */
[tabindex="-1"]:focus { outline: none; }

[hidden] { display: none !important; }

small, .sub { font-size: 14px; line-height: 20px; color: var(--muted); }

@media (max-width: 639px) {
  :root { --gutter: 16px; }
}