:root {
  color-scheme: light;
  --ink: #17211b;
  --muted: #647069;
  --paper: #fffdf7;
  --background: #f1f2e9;
  --accent: #d7ff5f;
  --deep: #173d2a;
  --line: #cfd4c8;
  --shadow: 0 14px 34px rgb(23 61 42 / 10%);
}

* { box-sizing: border-box; }
body { margin: 0; color: var(--ink); background: var(--background); font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif; }
.shell { width: min(68rem, calc(100% - 2rem)); margin-inline: auto; }
.hero { padding: clamp(3rem, 10vw, 7rem) 0 3rem; color: white; background: var(--deep); }
.eyebrow { margin: 0 0 .7rem; color: #bddd9e; font-size: .76rem; font-weight: 850; letter-spacing: .13em; text-transform: uppercase; }
h1 { max-width: 10ch; margin: 0; font-size: clamp(3.25rem, 11vw, 7.25rem); letter-spacing: -.065em; line-height: .89; }
.intro { max-width: 31rem; margin: 1.4rem 0 1.6rem; color: #d5ddd7; font-size: clamp(1rem, 3vw, 1.25rem); line-height: 1.55; }
.continue-button { display: inline-flex; gap: 2rem; align-items: center; justify-content: space-between; min-width: min(100%, 17rem); padding: .9rem 1rem; border-radius: .35rem; color: var(--deep); background: var(--accent); font-weight: 850; text-decoration: none; }
.continue-button:focus-visible, .lesson-card a:focus-visible, button:focus-visible { outline: 3px solid #ffbd5f; outline-offset: 3px; }
.progress-summary { margin-top: 1.1rem; color: #aebdb3; font-size: .86rem; }
main { padding: 3rem 0 6rem; }
.section-heading { display: flex; gap: 1rem; align-items: end; justify-content: space-between; }
.section-heading .eyebrow { color: #59735f; }
.section-heading h2 { margin: 0; font-size: clamp(2rem, 6vw, 3.5rem); letter-spacing: -.045em; }
.reset-button { padding: .45rem 0; border: 0; border-bottom: 1px solid currentColor; color: var(--muted); background: transparent; cursor: pointer; font: inherit; font-size: .8rem; }
.filters { display: flex; gap: .5rem; margin: 1.5rem 0; overflow-x: auto; scrollbar-width: none; }
.filter { flex: 0 0 auto; padding: .55rem .85rem; border: 1px solid var(--line); border-radius: 999px; color: var(--ink); background: transparent; cursor: pointer; font: inherit; font-size: .85rem; font-weight: 750; }
.filter[aria-pressed="true"], .filter:hover { border-color: var(--deep); color: white; background: var(--deep); }
.lesson-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(min(100%, 19rem), 1fr)); gap: 1rem; }
.lesson-card { position: relative; min-height: 19rem; padding: 1.35rem; border: 1px solid var(--line); border-radius: .5rem; background: var(--paper); box-shadow: var(--shadow); }
.lesson-card[data-complete="true"] { background: #e8f0dc; box-shadow: none; }
.lesson-card a { color: inherit; text-decoration: none; }
.lesson-card a::after { position: absolute; inset: 0; content: ""; }
.card-meta { display: flex; justify-content: space-between; color: var(--muted); font-size: .73rem; font-weight: 800; letter-spacing: .04em; text-transform: uppercase; }
.lesson-card h2 { margin: 2.2rem 0 .75rem; font-size: 1.75rem; letter-spacing: -.035em; line-height: 1.05; }
.lesson-card p { color: var(--muted); line-height: 1.55; }
.lesson-card .source { margin-top: 1.4rem; padding-top: 1rem; border-top: 1px solid var(--line); font-size: .78rem; }
.status { position: absolute; right: 1.35rem; bottom: 1.2rem; color: #496250; font-size: .74rem; font-weight: 800; }
.empty { grid-column: 1 / -1; padding: 3rem; border: 1px dashed var(--line); text-align: center; }
footer { padding: 1.5rem 0 2.5rem; border-top: 1px solid var(--line); color: var(--muted); font-size: .82rem; }
[hidden] { display: none !important; }
@media (max-width: 34rem) { .section-heading { align-items: start; } .lesson-card { min-height: 17rem; } }
@media (prefers-reduced-motion: reduce) { *, *::before, *::after { scroll-behavior: auto !important; transition: none !important; } }