/* London School Zones — brick red / slate / exercise-book paper */
:root {
  --brick: #9c3b2b;
  --brick-d: #7a2c1f;
  --brick-bg: #f8e9e5;
  --slate: #2f3b52;
  --slate-bg: #e9edf3;
  --paper: #fdfbf7;
  --ink: #232323;
  --muted: #5d6270;
  --line: #e4ddd2;
  --margin: #e8a69a;
  --serif: "Merriweather", Georgia, serif;
  --sans: "Mulish", system-ui, -apple-system, "Segoe UI", sans-serif;
}
*, *::before, *::after { box-sizing: border-box; }
body { margin: 0; background: var(--paper); color: var(--ink); font-family: var(--sans); font-size: 1.06rem; line-height: 1.75; }
img { max-width: 100%; height: auto; }
a { color: var(--brick); font-weight: 600; text-underline-offset: 3px; }
a:hover { color: var(--slate); }
h1, h2, h3 { font-family: var(--serif); color: var(--slate); line-height: 1.25; }
h1 { font-size: clamp(1.9rem, 5.2vw, 2.9rem); font-weight: 900; margin: .4rem 0 1rem; }
h2 { font-size: clamp(1.35rem, 3.2vw, 1.75rem); font-weight: 700; margin: 2.4rem 0 .7rem; }
h3 { font-family: var(--sans); font-size: 1.12rem; font-weight: 800; margin: 1.5rem 0 .4rem; color: var(--brick); }
p, ul, ol { margin: 0 0 1rem; }
.pg { width: min(880px, 100% - 32px); margin-inline: auto; }
.skip { position: absolute; left: -9999px; }
.skip:focus { left: 10px; top: 10px; background: #fff; padding: 8px; z-index: 9; }

.hdr { background: var(--slate); }
.hdr-in { display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between; gap: 6px 18px; padding: 14px 0; }
.logo img { height: 38px; width: auto; display: block; }
.hnav { overflow-x: auto; max-width: 100%; }
.hnav ul { list-style: none; display: flex; gap: 16px; margin: 0; padding: 0; white-space: nowrap; }
.hnav a { color: #d7dde8; text-decoration: none; font-size: .92rem; font-weight: 600; }
.hnav a:hover, .hnav a[aria-current] { color: #fff; box-shadow: inset 0 -2px 0 var(--margin); }
.ruled { height: 6px; background: var(--brick); }

.crumbs { font-size: .85rem; color: var(--muted); margin-top: 20px; }
.crumbs a { color: var(--muted); font-weight: 400; }
.crumbs .sep { margin: 0 5px; }

/* notebook-style intro block with a red margin line */
.notebook { background: #fff; border: 1px solid var(--line); border-left: 4px solid var(--margin); padding: 26px 26px 18px 30px; margin: 24px 0; background-image: repeating-linear-gradient(transparent 0 31px, #eef1f6 31px 32px); }
.notebook p { font-size: 1.12rem; }
.chapter { font-family: var(--sans); font-weight: 800; color: var(--brick); text-transform: uppercase; letter-spacing: .12em; font-size: .78rem; margin: 26px 0 0; }
.lede { font-size: 1.15rem; color: #3a3f4a; }
.dated { font-size: .85rem; color: var(--muted); }

.lessons { counter-reset: l; list-style: none; padding: 0; margin: 20px 0; display: grid; gap: 12px; }
.lessons a { counter-increment: l; display: grid; grid-template-columns: 46px 1fr; gap: 0 12px; background: #fff; border: 1px solid var(--line); padding: 14px 16px; text-decoration: none; color: var(--ink); border-radius: 4px; }
.lessons a::before { content: counter(l); grid-row: span 2; font-family: var(--serif); font-weight: 900; font-size: 1.6rem; color: var(--brick); line-height: 1; }
.lessons a:hover { border-color: var(--brick); }
.lessons b { font-family: var(--serif); color: var(--slate); }
.lessons span { color: var(--muted); font-weight: 400; }

.check { background: var(--slate-bg); border-radius: 4px; padding: 16px 20px; margin: 20px 0; }
.check.red { background: var(--brick-bg); }
.check p:last-child { margin: 0; }
.ticklist { list-style: none; padding: 0; }
.ticklist li { padding-left: 28px; position: relative; margin-bottom: .5rem; }
.ticklist li::before { content: "✎"; position: absolute; left: 0; color: var(--brick); }
table { width: 100%; border-collapse: collapse; background: #fff; margin: 18px 0; font-size: .95rem; }
th, td { border: 1px solid var(--line); padding: 10px 12px; text-align: left; vertical-align: top; }
th { background: var(--slate); color: #fff; }
.tw { overflow-x: auto; }

details.faq { background: #fff; border: 1px solid var(--line); border-left: 4px solid var(--margin); margin: 10px 0; padding: 0 18px; }
details.faq summary { cursor: pointer; font-weight: 800; padding: 13px 0; color: var(--slate); }
details.faq > div { padding-bottom: 8px; }

.agent { background: var(--brick); color: #f6e3de; padding: 28px; margin: 44px 0 10px; border-radius: 4px; }
.agent .lab { text-transform: uppercase; letter-spacing: .12em; font-size: .78rem; font-weight: 800; color: #ffd4ca; }
.agent h2 { color: #fff; margin: .3rem 0 .6rem; }
.btn { display: inline-block; background: #fff; color: var(--brick); text-decoration: none; font-weight: 800; padding: 12px 20px; border-radius: 4px; }
.btn:hover { background: var(--slate); color: #fff; }

.ftr { background: var(--slate); color: #cdd4e0; margin-top: 56px; padding: 36px 0 24px; font-size: .93rem; }
.ftr a { color: #fff; font-weight: 600; }
.ftr ul { list-style: none; padding: 0; }
.ftr-cols { display: grid; gap: 20px; }
@media (min-width: 760px) { .ftr-cols { grid-template-columns: 2fr 1fr; } }
.ftr-h { font-family: var(--serif); color: #fff; margin-bottom: .3rem; }
.agent-credit { border-top: 1px solid rgba(255,255,255,.15); padding-top: 14px; }
.copy { font-size: .8rem; opacity: .75; }

.agent-line{display:block;font-size:.72rem;line-height:1.4;opacity:.85}