:root {
  --ink: #20201d;
  --muted: #77756e;
  --line: #dedbd2;
  --paper: #f6f4ef;
  --card: #fffefa;
  --accent: #9a563e;
  --accent-soft: #f0ded5;
  --olive: #68735d;
  --shadow: 0 18px 55px rgba(46, 37, 27, .08);
}
* { box-sizing: border-box; }
body { margin: 0; background: var(--paper); color: var(--ink); font-family: Arial, sans-serif; line-height: 1.55; }
button, a { font: inherit; }
button { cursor: pointer; }
.shell { max-width: 1180px; margin: 0 auto; padding: 38px 24px 60px; }
.hero { display: flex; justify-content: space-between; gap: 30px; align-items: flex-end; padding: 34px 0 38px; border-bottom: 1px solid var(--line); }
.eyebrow { color: var(--accent); text-transform: uppercase; letter-spacing: .11em; font-size: .72rem; font-weight: 700; }
h1, h2, h3, p { margin-top: 0; }
h1 { max-width: 680px; margin-bottom: 12px; font: 500 clamp(2.4rem, 6vw, 5.6rem)/.98 Georgia, serif; letter-spacing: -.045em; }
.lede { max-width: 630px; color: var(--muted); font-size: 1.05rem; }
.progress-card { min-width: 210px; padding: 18px; border: 1px solid var(--line); background: rgba(255,254,250,.65); }
.progress-card span, .progress-card small { display: block; color: var(--muted); font-size: .83rem; }
.progress-card strong { display: block; font: 600 2.4rem Georgia, serif; margin: 6px 0 10px; }
.progress { height: 5px; background: #e6e1d7; overflow: hidden; }
.progress i { display: block; height: 100%; width: 0; background: var(--accent); transition: width .4s ease; }
.tabs { display: flex; gap: 8px; flex-wrap: wrap; padding: 22px 0; }
.tab { border: 1px solid var(--line); background: transparent; color: var(--muted); padding: 9px 15px; border-radius: 999px; }
.tab.active { background: var(--ink); color: white; border-color: var(--ink); }
.focus-strip { display: flex; justify-content: space-between; align-items: center; gap: 20px; padding: 25px 28px; margin: 8px 0 42px; background: #2f332e; color: #f9f5ed; box-shadow: var(--shadow); }
.focus-strip .eyebrow { color: #e2b59f; }
.focus-strip h2 { max-width: 690px; margin: 5px 0; font: 500 clamp(1.4rem, 3vw, 2.35rem)/1.05 Georgia, serif; }
.focus-strip p { margin-bottom: 0; color: #c4c5bc; }
.practice-strip { display: flex; justify-content: space-between; align-items: center; gap: 20px; padding: 22px 26px; margin: -20px 0 42px; background: #e9e5dc; border: 1px solid var(--line); }
.practice-strip h2 { margin: 5px 0; font: 500 clamp(1.35rem, 3vw, 2rem)/1.05 Georgia, serif; }
.practice-strip p { margin-bottom: 0; color: var(--muted); }
.primary, .secondary { border: 0; padding: 10px 15px; white-space: nowrap; }
.primary { color: #2f332e; background: #f0d7c9; }
.section-heading, .panel-heading { display: flex; justify-content: space-between; align-items: baseline; gap: 16px; }
.section-heading h2 { margin: 4px 0 18px; font: 500 2.2rem Georgia, serif; }
.count, .panel-heading span { color: var(--muted); font-size: .82rem; }
.lesson-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 16px; }
.artwork-section { margin-top: 58px; padding-top: 12px; border-top: 1px solid var(--line); }
.artwork-controls { display: flex; align-items: center; gap: 12px; margin: 4px 0 12px; color: var(--muted); font-size: .88rem; }
.artwork-controls select { border: 1px solid var(--line); background: var(--card); color: var(--ink); padding: 9px 12px; min-width: 240px; }
.artwork-grid { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 16px; }
.artwork-card { background: var(--card); border: 1px solid var(--line); min-width: 0; }
.artwork-card img, .artwork-placeholder { display: block; width: 100%; height: 190px; object-fit: cover; background: #ebe7de; }
.artwork-placeholder { display: grid; place-content: center; text-align: center; color: var(--muted); font-size: .9rem; padding: 18px; }
.artwork-placeholder small { font-size: .75rem; }
.artwork-body { padding: 16px; }
.artwork-body h3 { margin: 12px 0 3px; font: 500 1.35rem/1.1 Georgia, serif; }
.artwork-type { color: var(--olive); font-size: .75rem; }
.artwork-artist { color: var(--accent); margin-bottom: 7px; font-size: .9rem; }
.artwork-medium, .artwork-note { color: #56544d; font-size: .84rem; }
.artwork-note { min-height: 58px; margin-bottom: 14px; }
.artwork-meta { display: grid; gap: 4px; color: var(--muted); font-size: .72rem; border-top: 1px solid #ebe8e0; padding-top: 10px; margin-bottom: 11px; }
.lesson-card { min-height: 270px; padding: 22px; background: var(--card); border: 1px solid var(--line); display: flex; flex-direction: column; box-shadow: 0 4px 18px rgba(50,40,30,.025); }
.lesson-card.upcoming { background: #f1f1eb; }
.card-top, .card-actions { display: flex; justify-content: space-between; align-items: center; gap: 12px; }
time { color: var(--muted); font-size: .83rem; }
.badge { padding: 4px 9px; border-radius: 999px; font-size: .72rem; }
.badge.done { color: #53614b; background: #e2eadc; }
.badge.upcoming { color: #805b2e; background: #f2e7c9; }
.lesson-card h3 { margin: 18px 0 4px; font: 500 1.55rem/1.1 Georgia, serif; }
.lecturer { color: var(--accent); font-size: .9rem; margin-bottom: 14px; }
.lesson-card > p:not(.lecturer) { color: #56544d; font-size: .94rem; }
.chips { display: flex; gap: 6px; flex-wrap: wrap; margin-top: auto; padding: 14px 0 18px; }
.chips span { border-bottom: 1px solid #d8b2a1; color: #765345; font-size: .78rem; }
.secondary { background: var(--ink); color: white; font-size: .85rem; }
.text-link { color: var(--accent); text-decoration: none; font-size: .85rem; }
.lower-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; margin-top: 48px; }
.panel { background: var(--card); border: 1px solid var(--line); padding: 22px; }
.panel h2 { margin-bottom: 0; font: 500 1.5rem Georgia, serif; }
.concept-list, .artist-list { list-style: none; padding: 16px 0 0; margin: 0; display: grid; gap: 9px; }
.concept-list li, .artist-list li { display: flex; justify-content: space-between; align-items: center; padding-bottom: 8px; border-bottom: 1px solid #ebe8e0; font-size: .92rem; }
.dot { width: 7px; height: 7px; border-radius: 50%; background: var(--accent); display: inline-block; margin-left: 8px; }
.artist-list li span { color: var(--muted); }
footer { color: var(--muted); font-size: .78rem; text-align: center; margin-top: 45px; }
.lesson-dialog { width: min(760px, calc(100vw - 30px)); max-height: 86vh; overflow: auto; border: 1px solid var(--line); padding: 32px; background: var(--card); color: var(--ink); box-shadow: 0 30px 100px rgba(20,15,10,.25); }
.lesson-dialog::backdrop { background: rgba(30,28,23,.58); }
.dialog-close { position: absolute; top: 12px; left: 14px; width: 34px; height: 34px; border: 0; border-radius: 50%; background: #eee9df; color: var(--ink); font-size: 1.4rem; line-height: 1; }
.lesson-dialog h2 { margin: 8px 0 4px; font: 500 clamp(2rem, 5vw, 3.6rem)/1 Georgia, serif; }
.dialog-lecturer { color: var(--accent); margin-bottom: 8px; }
.source-note { color: var(--muted); font-size: .85rem; margin-bottom: 22px; }
.lesson-dialog h3 { margin: 0 0 8px; font: 600 1.08rem Georgia, serif; }
.summary-block { border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); padding: 22px 0; }
.summary-block p, .source-block p { color: #56544d; }
.placeholder-note, .muted { color: var(--muted) !important; font-size: .9rem; }
.dialog-columns { display: grid; grid-template-columns: 1fr 1fr; gap: 28px; padding: 24px 0; }
.dialog-columns ul { margin: 0; padding-right: 18px; color: #56544d; }
.source-block { border-top: 1px solid var(--line); padding-top: 20px; }
.source-block .text-link, .source-block .muted { display: block; margin-top: 14px; }
.review-toggle { display: block; margin-top: 18px; color: #56544d; font-size: .9rem; }
.review-toggle input { accent-color: var(--accent); margin-left: 7px; }
.answer-list { display: grid; gap: 10px; margin: 24px 0 16px; }
.answer { border: 1px solid var(--line); background: #f8f6f0; color: var(--ink); padding: 14px 16px; text-align: right; }
.answer:hover:not(:disabled) { border-color: var(--accent); background: var(--accent-soft); }
.answer.correct { border-color: var(--olive); background: #e2eadc; }
.answer.incorrect { border-color: #a85c4a; background: #f2ddd6; }
.answer:disabled { cursor: default; }
.practice-feedback { min-height: 28px; color: #56544d; }
.next-question { margin-top: 8px; }
@media (max-width: 760px) {
  .shell { padding: 22px 16px 42px; }
  .hero, .focus-strip { display: block; }
  .progress-card { margin-top: 24px; }
  .focus-strip .primary { margin-top: 18px; }
  .lesson-grid, .lower-grid, .dialog-columns { grid-template-columns: 1fr; }
  .artwork-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .artwork-controls { align-items: flex-start; flex-direction: column; }
  .practice-strip { display: block; }
  .practice-strip .primary { margin-top: 18px; }
  h1 { font-size: 3.3rem; }
}