:root {
  color-scheme: light;
  --paper: #f7f0db;
  --ink: #242637;
  --blue: #263890;
  --red: #b43d26;
  --line: #b6ab8c;
  --mono: "Cascadia Mono", Consolas, monospace;
}
* { box-sizing: border-box; }
body { margin: 0; background: var(--paper); color: var(--ink); font: 1rem/1.6 "Trebuchet MS", system-ui, sans-serif; }
a { color: inherit; }
a:focus-visible { outline: 3px solid var(--red); outline-offset: 5px; }
h1, h2, h3, p, figure, dl, dd { margin: 0; }
.page { width: min(76rem, calc(100% - 4rem)); margin-inline: auto; }
.skip { position: absolute; inset: .75rem auto auto 1rem; transform: translateY(-180%); padding: .6rem 1rem; z-index: 1; background: #fff; }
.skip:focus { transform: none; }
.mast, .foot { display: flex; align-items: center; justify-content: space-between; gap: 1.25rem; padding-block: 1.15rem; }
.mast { border-bottom: 1px solid var(--line); }
.wordmark { display: inline-flex; align-items: center; gap: .7rem; text-decoration: none; color: var(--blue); font-size: 1.34rem; font-weight: 800; }
.mark { display: inline-flex; align-items: center; gap: .19rem; height: 1.15rem; }
.mark i { display: block; width: .19rem; height: 54%; background: currentColor; }
.mark i:nth-child(2) { height: 90%; }
.mark i:nth-child(3) { height: 65%; }
.mark i:nth-child(4) { height: 38%; }
nav { display: flex; flex-wrap: wrap; gap: .45rem 1.7rem; }
nav a, .foot a { text-decoration-thickness: .08em; text-underline-offset: .24em; font-weight: 700; }
.hero { display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1.1fr); gap: clamp(1.8rem, 6vw, 6rem); align-items: center; padding-block: clamp(3rem, 6vw, 5.6rem); }
.series, figcaption, .number { font: 700 .8rem/1.35 var(--mono); letter-spacing: .035em; }
.series { color: var(--blue); margin-bottom: .9rem; }
.series span { color: var(--red); }
h1 { color: var(--blue); font-family: "Arial Black", "Trebuchet MS", system-ui, sans-serif; font-size: clamp(3.6rem, 8vw, 7.4rem); font-weight: 900; line-height: .9; letter-spacing: -.075em; }
h1 span { color: var(--red); }
.lede { margin-top: 1.5rem; max-width: 30ch; font-size: clamp(1.03rem, 1.65vw, 1.25rem); }
.button { display: inline-flex; align-items: center; gap: 1.3rem; padding: .75rem 1rem; margin-top: 1.5rem; color: #fffdf1; background: var(--blue); text-decoration: none; font-weight: 800; }
.button:hover { background: #17265f; }
.field img { display: block; width: 100%; height: auto; background: var(--blue); }
figcaption { display: flex; gap: .8rem; padding: .7rem 0; border-bottom: 1px solid var(--line); }
figcaption span { color: var(--red); }
.practice { border-top: 1px solid var(--line); padding-top: 1.45rem; }
.section-head { display: flex; flex-wrap: wrap; align-items: baseline; justify-content: space-between; gap: .4rem 1.25rem; margin-bottom: 1.35rem; }
h2 { color: var(--blue); font-size: clamp(1.65rem, 3.7vw, 2.7rem); letter-spacing: -.04em; line-height: 1.08; }
.exercises { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); padding: 0; margin: 0; list-style: none; border-block: 1px solid var(--line); }
.exercises li { padding: 1.1rem 1.4rem 1.35rem; }
.exercises li:first-child { padding-left: 0; }
.exercises li + li { border-left: 1px solid var(--line); }
.number { display: block; margin-bottom: .45rem; color: var(--red); }
h3 { font-size: 1.35rem; line-height: 1.25; margin-bottom: .45rem; }
.listening { display: grid; grid-template-columns: minmax(0, 1.4fr) minmax(0, 1fr); gap: 2rem; margin-block: 2.1rem; padding: clamp(1.1rem, 3vw, 2.2rem); background: #e3e6fa; }
.listening p { margin-top: .7rem; max-width: 52ch; }
.notes { border-left: 1px solid #8892c2; padding-left: 1.3rem; }
dt { font-weight: 800; color: var(--blue); }
dd + dt { margin-top: .7rem; }
.foot { border-top: 1px solid var(--line); font-size: .9rem; }
.foot p span { color: var(--red); }
@media (max-width: 49rem) {
  .page { width: calc(100% - 2rem); }
  .hero { grid-template-columns: 1fr; gap: 1.7rem; }
  h1 { font-size: clamp(3.15rem, 10vw, 5rem); }
  .exercises { grid-template-columns: 1fr; }
  .exercises li { padding-inline: 0; }
  .exercises li + li { border-left: 0; border-top: 1px solid var(--line); }
  .listening { grid-template-columns: 1fr; gap: 1rem; }
}
@media (max-width: 25rem) {
  .mast, .foot { align-items: flex-start; flex-direction: column; gap: .5rem; }
}