:root {
  --ink: #1a1a1a; --paper: #fffdf8; --accent: #7a3b10; --accent-ink: #fff;
  --rule: #d8d2c4; --note-bg: #f4efe4; --focus: #0b5cad;
}
* { box-sizing: border-box; }
html { font-size: 112.5%; }
body {
  margin: 0; color: var(--ink); background: var(--paper);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Arial, sans-serif;
  line-height: 1.6;
}
.skip { position: absolute; left: -9999px; top: 0; background: var(--accent); color: var(--accent-ink); padding: .5rem 1rem; z-index: 10; }
.skip:focus { left: 0; }
header { background: var(--accent); color: var(--accent-ink); padding: 1.1rem 1.25rem .9rem; }
.brand { margin: 0; font-size: 1.6rem; font-weight: 700; }
.brand a { color: inherit; text-decoration: none; }
.tagline { margin: .15rem 0 0; opacity: .92; font-size: .95rem; }
nav[aria-label="Site"] { background: #2e2419; padding: .4rem 1.25rem; }
.nav-main { list-style: none; margin: 0; padding: 0; display: flex; flex-wrap: wrap; gap: .25rem 1.25rem; align-items: center; }
.nav-main a { color: #f5eee2; text-decoration: none; padding: .35rem 0; display: inline-block; }
.nav-main a:hover, .nav-main a:focus { text-decoration: underline; }
.nav-main a[aria-current="page"] { font-weight: 700; text-decoration: underline; }
.nav-main details { color: #f5eee2; }
.nav-main summary { cursor: pointer; padding: .35rem 0; }
.nav-main details ul { list-style: none; margin: .25rem 0 .5rem; padding: .25rem 0 .25rem 1rem; border-left: 2px solid #6b5638; }
main { max-width: 46rem; margin: 0 auto; padding: 1.5rem 1.25rem 3rem; }
h1 { font-size: 1.9rem; line-height: 1.25; border-bottom: 3px solid var(--accent); padding-bottom: .3rem; }
h2 { font-size: 1.45rem; margin-top: 2.2rem; }
h3 { font-size: 1.18rem; margin-top: 1.8rem; }
h4 { font-size: 1.02rem; font-style: italic; margin-top: 1.4rem; }
a { color: var(--focus); }
a:focus-visible { outline: 3px solid var(--focus); outline-offset: 2px; }
table { border-collapse: collapse; width: 100%; margin: 1rem 0; }
th, td { border: 1px solid var(--rule); padding: .5rem .6rem; text-align: left; vertical-align: top; }
th { background: var(--note-bg); }
td p { margin: 0 0 .35rem; }
.note { background: var(--note-bg); border-left: 5px solid var(--accent); padding: .75rem 1rem; margin: 1.25rem 0; }
.note-label { font-weight: 700; margin: 0 0 .35rem; }
.note p { margin: 0 0 .4rem; }
.fillin { background: #eef3f8; border-left: 5px solid var(--focus); padding: .5rem .8rem; }
.placeholder { font-style: italic; }
.exercise { background: var(--note-bg); padding: .4rem .6rem; border: 1px solid var(--rule); }
.pager { display: flex; justify-content: space-between; gap: 1rem; margin-top: 3rem; border-top: 1px solid var(--rule); padding-top: 1rem; }
footer { background: #2e2419; color: #f5eee2; padding: 1.25rem; text-align: center; font-size: .9rem; }
footer a { color: #ffd9a8; }
@media (max-width: 640px) { html { font-size: 106%; } .pager { flex-direction: column; } }
@media (prefers-reduced-motion: reduce) { * { scroll-behavior: auto; } }