/* Scoped to reading sheets; the Kingdom shell keeps its own appearance. */
.paper-sheet[data-lesson-theme]:where(:not([data-lesson-theme="original"])) {
  --lp-bg:#fffbed; --lp-ink:#302b26; --lp-accent:#715022; --lp-line:rgba(74,92,115,.14);
  --lp-panel:rgba(255,255,255,.58); --lp-border:rgba(68,58,43,.26);
  color:var(--lp-ink); background-color:var(--lp-bg); background-image:none;
  border:1px solid var(--lp-border); overflow-wrap:anywhere;
}
.paper-sheet:where([data-lesson-theme]):where(:not([data-lesson-theme="original"]))[data-lesson-color="1"] { --lp-bg:#edf5fa; --lp-accent:#275875; }
.paper-sheet:where([data-lesson-theme]):where(:not([data-lesson-theme="original"]))[data-lesson-color="2"] { --lp-bg:#faedf0; --lp-accent:#823e52; }
.paper-sheet[data-lesson-theme="notebook"] {
  background-image:linear-gradient(90deg, transparent 22px, #bf77775c 22px, #bf77775c 23px, transparent 23px), repeating-linear-gradient(transparent 0 31px,var(--lp-line) 31px 32px);
}
.paper-sheet[data-lesson-theme="book"] { --lp-bg:#f5ead5; background-image:linear-gradient(90deg,#70572726,transparent 24px,transparent 97%,#7057271a); border-radius:4px 14px 14px 4px; }
.paper-sheet[data-lesson-theme="book"][data-lesson-color="1"] { --lp-bg:#eaf0e3; --lp-accent:#435f32; }
.paper-sheet[data-lesson-theme="book"][data-lesson-color="2"] { --lp-bg:#f0eaf6; --lp-accent:#66417d; }
.paper-sheet[data-lesson-theme="book"] .lesson-block > p { font-family:Georgia,serif; font-size:18px; line-height:1.9; }
.paper-sheet[data-lesson-theme="newspaper"] { --lp-bg:#f3f1e9; --lp-accent:#34332d; border-radius:2px; border-top:5px double var(--lp-accent); }
.paper-sheet[data-lesson-theme="newspaper"][data-lesson-color="1"] { --lp-bg:#f2e5d0; --lp-accent:#604728; }
.paper-sheet[data-lesson-theme="newspaper"][data-lesson-color="2"] { --lp-bg:#edf2f4; --lp-accent:#365262; }
.paper-sheet[data-lesson-theme="newspaper"] .lesson-block > h2 { font-family:Georgia,serif; border-block:3px double var(--lp-accent); padding-block:18px; }
.paper-sheet[data-lesson-theme="sticky"] { --lp-bg:#fff2ac; --lp-accent:#715117; border-radius:2px 2px 24px 2px; box-shadow:5px 12px 28px #0004; background-image:linear-gradient(#9d852415,transparent 70px); }
.paper-sheet[data-lesson-theme="sticky"][data-lesson-color="1"] { --lp-bg:#ffdfc8; --lp-accent:#874127; }
.paper-sheet[data-lesson-theme="sticky"][data-lesson-color="2"] { --lp-bg:#ddf2da; --lp-accent:#345d34; }
.paper-sheet[data-lesson-theme="sticky"] blockquote { background:var(--lp-panel); padding:22px; box-shadow:3px 5px 0 #0000000a; }
.paper-sheet[data-lesson-theme="blueprint"],.paper-sheet[data-lesson-theme="charcoal"],.paper-sheet[data-lesson-theme="crown"],.paper-sheet[data-lesson-theme="checkmate"] { --lp-ink:#f5f1e7; --lp-panel:rgba(0,0,0,.22); --lp-border:rgba(255,255,255,.28); color-scheme:dark; }
.paper-sheet[data-lesson-theme="blueprint"] { --lp-bg:#10283f; --lp-accent:#94d9ff; --lp-line:rgba(145,209,250,.065); background-image:linear-gradient(var(--lp-line) 1px,transparent 1px),linear-gradient(90deg,var(--lp-line) 1px,transparent 1px); background-size:28px 28px; }
.paper-sheet[data-lesson-theme="blueprint"][data-lesson-color="1"] { --lp-bg:#103738; --lp-accent:#8de0d0; }
.paper-sheet[data-lesson-theme="blueprint"][data-lesson-color="2"] { --lp-bg:#272640; --lp-accent:#c6bbff; }
.paper-sheet[data-lesson-theme="charcoal"] { --lp-bg:#202021; --lp-accent:#edcf88; border-top:3px solid var(--lp-accent); }
.paper-sheet[data-lesson-theme="charcoal"][data-lesson-color="1"] { --lp-bg:#22272d; --lp-accent:#dae2ed; }
.paper-sheet[data-lesson-theme="charcoal"][data-lesson-color="2"] { --lp-bg:#302522; --lp-accent:#f2ba94; }
.paper-sheet[data-lesson-theme]:not([data-lesson-theme="original"]) :is(p,li,td,pre,figcaption,dt,dd,strong,h2.serif,h4,h5,h6,blockquote,.cp-label,.reflect-label,.not-started-item .t,.not-started-item .s,.chart-figure .cf-note) { color:var(--lp-ink) !important; }
.paper-sheet[data-lesson-theme]:not([data-lesson-theme="original"]) :is(h3,summary,th,.lesson-tag,.lesson-tag.flagship,.signoff,.draft-badge,.chart-figure .cf-editorial) { color:var(--lp-accent) !important; }
.paper-sheet[data-lesson-theme]:not([data-lesson-theme="original"]) :is(blockquote,th,td,.draft-badge,.lesson-solo-nav) { border-color:var(--lp-border) !important; }
.paper-sheet[data-lesson-theme]:not([data-lesson-theme="original"]) :is(.production-note,.chart-placeholder,.chart-figure .cf-editorial,.not-started-item,textarea.reflect-field) { color:var(--lp-ink) !important; background:var(--lp-panel) !important; border-color:var(--lp-border) !important; }
.paper-sheet[data-lesson-theme]:not([data-lesson-theme="original"]) .lesson-block ol li::marker { color:var(--lp-accent) !important; }
.paper-sheet[data-lesson-theme]:not([data-lesson-theme="original"]) .lesson-nav-btn { color:var(--lp-ink); border-color:var(--lp-border); }
.paper-sheet[data-lesson-theme]:not([data-lesson-theme="original"]) .lesson-nav-btn:hover:not(:disabled) { color:var(--lp-accent); border-color:var(--lp-accent); }
.paper-sheet[data-lesson-theme]:not([data-lesson-theme="original"]) .lesson-block a { color:var(--lp-accent); text-decoration:underline; }
.lesson-look { display:flex; flex-wrap:wrap; align-items:end; gap:12px; margin:12px 24px 0; padding:14px; border:1px solid var(--lp-border); border-radius:8px; background:var(--lp-bg); color:var(--lp-ink); font:12px/1.5 Inter,Arial,sans-serif; }
.lesson-look label { display:grid; gap:4px; flex:1 1 130px; }
.lesson-look :is(select,button) { font:inherit; font-size:13px; color:var(--lp-ink); background:var(--lp-bg); border:1px solid var(--lp-border); border-radius:6px; min-height:44px; padding:8px 10px; cursor:pointer; max-width:100%; }
.paper-sheet[data-lesson-theme]:not([data-lesson-theme="original"]) :is(select,button,textarea,a,summary):focus-visible { outline:3px solid var(--lp-accent); outline-offset:3px; }
.lesson-look-status { flex-basis:100%; font-size:11px; }
.lesson-look-status:empty { display:none; }
@media(max-width:520px) { .lesson-look { margin-inline:12px; gap:8px; } .paper-sheet[data-lesson-theme]:not([data-lesson-theme="original"]) .lesson-wrap { padding-inline:24px; } }
@media print { .lesson-look-box, .lesson-look { display:none !important; } .paper-sheet[data-lesson-theme]:not([data-lesson-theme="original"]) { --lp-ink:#111; --lp-accent:#333; background:#fff !important; box-shadow:none; } }
.paper-sheet[data-lesson-theme]:not([data-lesson-theme="original"]) .lesson-wrap :is(.data-table,.mbm-roadmap-table) td { color:var(--lp-ink) !important; border-color:var(--lp-border) !important; }
.paper-sheet[data-lesson-theme]:not([data-lesson-theme="original"]) .lesson-wrap :is(.data-table,.mbm-roadmap-table) th { color:var(--lp-accent) !important; border-color:var(--lp-border) !important; }
.paper-sheet[data-lesson-theme]:not([data-lesson-theme="original"]) .lesson-wrap :is(.data-table,.mbm-roadmap-table) tbody tr:hover td { background:var(--lp-panel) !important; }

/* Kingdom collection: ornament stays around the reading area. */
.paper-sheet[data-lesson-theme="chessboard"] {
  --lp-bg:#faf2df; --lp-accent:#655024; --lp-chess:#252320;
  border:12px solid transparent; border-radius:2px;
  background:linear-gradient(var(--lp-bg),var(--lp-bg)) padding-box,
    conic-gradient(var(--lp-chess) 25%,#ecdfbf 0 50%,var(--lp-chess) 0 75%,#ecdfbf 0) border-box;
  background-size:auto,32px 32px;
  box-shadow:0 0 0 1px #b99751,0 24px 55px #0005;
}
.paper-sheet[data-lesson-theme="chessboard"][data-lesson-color="1"] { --lp-bg:#f2e4cb; --lp-accent:#69442e; --lp-chess:#60402d; }
.paper-sheet[data-lesson-theme="chessboard"][data-lesson-color="2"] { --lp-bg:#edf1f7; --lp-accent:#314f72; --lp-chess:#203750; }
.paper-sheet[data-lesson-theme="chessboard"] .lesson-block > h2 { border-bottom:3px double var(--lp-accent); padding-bottom:20px; }
.paper-sheet[data-lesson-theme="ledger"] {
  --lp-bg:#f4e7cc; --lp-accent:#753b32; --lp-leather:#592728;
  border:12px solid transparent; border-left-width:26px; border-radius:8px 14px 14px 8px;
  background:linear-gradient(90deg,#8f69232b,transparent 28px),linear-gradient(var(--lp-bg),var(--lp-bg));
  background-origin:padding-box; background-clip:padding-box;
  border-color:var(--lp-leather);
  box-shadow:inset 0 0 0 2px #b6934f,inset 5px 0 14px #5a37131a,-4px 0 0 #bc9459,0 24px 55px #0005;
}
.paper-sheet[data-lesson-theme="ledger"][data-lesson-color="1"] { --lp-bg:#edf0dc; --lp-accent:#34553d; --lp-leather:#254438; }
.paper-sheet[data-lesson-theme="ledger"][data-lesson-color="2"] { --lp-bg:#eeeaf3; --lp-accent:#404866; --lp-leather:#28344b; }
.paper-sheet[data-lesson-theme="ledger"] .lesson-block > h2 { font-family:Georgia,serif; border-block:1px solid #a88245; padding-block:20px; }
.paper-sheet[data-lesson-theme="library"] {
  --lp-bg:#f0dfbd; --lp-accent:#6b4828; --lp-stone:#735335;
  border:10px double var(--lp-stone); border-radius:100px 100px 8px 8px / 55px 55px 8px 8px;
  padding-top:40px;
  background-image:radial-gradient(ellipse at top,#fff5d355,transparent 60%),linear-gradient(90deg,#71451c20,transparent 45px,transparent calc(100% - 45px),#71451c20);
  box-shadow:inset 0 0 0 3px #c09b62,0 24px 55px #0005;
}
.paper-sheet[data-lesson-theme="library"][data-lesson-color="1"] { --lp-bg:#efeae0; --lp-accent:#5d5549; --lp-stone:#817667; }
.paper-sheet[data-lesson-theme="library"][data-lesson-color="2"] { --lp-bg:#f5e3d4; --lp-accent:#773f31; --lp-stone:#693a2b; }
.paper-sheet[data-lesson-theme="library"] .lesson-block > h2 { font-family:Georgia,serif; text-align:center; border-bottom:3px double var(--lp-accent); padding-bottom:24px; }
.paper-sheet:is([data-lesson-theme="ledger"],[data-lesson-theme="library"]) .lesson-block > p { font-family:Georgia,serif; font-size:18px; line-height:1.9; }
@media(max-width:520px) {
  .paper-sheet[data-lesson-theme="chessboard"] { border-width:8px; }
  .paper-sheet[data-lesson-theme="ledger"] { border-width:7px; border-left-width:14px; }
  .paper-sheet[data-lesson-theme="library"] { border-width:7px; padding-top:30px; }
}

/* Collapsible palette keeps the reading controls compact on phones. */
.lesson-palette-browser { flex-basis:100%; min-width:0; }
.lesson-palette-browser > summary { cursor:pointer; padding:10px 0; min-height:44px; box-sizing:border-box; }
.lesson-color-swatches { display:grid; grid-template-columns:repeat(auto-fit,minmax(120px,1fr)); gap:8px; padding-block:6px; }
.lesson-look .lesson-color-swatch { display:flex; align-items:center; gap:8px; text-align:left; }
.lesson-color-swatch::before { content:''; width:20px; height:20px; border-radius:50%; flex-shrink:0; background:var(--swatch-color); border:1px solid var(--lp-border); box-shadow:inset 0 0 0 1px #ffffff40; }
.lesson-look .lesson-color-swatch[aria-pressed="true"] { border:2px solid var(--lp-accent); font-weight:700; }
.lesson-module-controls { margin-top:16px; cursor:default; }
.lesson-module-controls > summary { cursor:pointer; padding:12px 0; font-size:14px; color:var(--gold,#ddbd76); }
.lesson-theme-sample { margin-top:10px; max-width:760px; }
.lesson-theme-sample .lesson-wrap { padding:20px 24px !important; }
.lesson-theme-sample .lesson-wrap p { margin:0; }
.mod-card .lesson-look { margin-inline:8px !important; padding:10px !important; }
.mod-card .lesson-color-swatches { grid-template-columns:repeat(auto-fit,minmax(110px,1fr)); }
.lesson-color-swatches { grid-template-columns:repeat(auto-fit,minmax(145px,1fr)); }
.lesson-look .lesson-color-swatch { font-size:12px; overflow-wrap:normal; }
.mod-card .lesson-color-swatches { grid-template-columns:repeat(auto-fit,minmax(130px,1fr)); }
/* Original restores the pre-theme reading paper and the original dark question card. */
[data-lesson-theme="original"] { --lp-bg:#f3eedf; --lp-ink:#302b26; --lp-accent:#715022; --lp-border:#a8997f; }
.lesson-questions[data-lesson-theme="original"] { --lp-bg:var(--panel-solid,#20242d); --lp-ink:var(--white,#f5f1e7); --lp-accent:var(--gold,#ddbd76); --lp-border:var(--hairline-strong,#777); }
.lesson-questions .lesson-look { margin:0 0 24px; }
.lesson-questions.paper-sheet :is(.q-prompt,.q-option,.q-hint,.q-statement,.private-toggle,.assign-head .eyebrow,.q-table td,.q-table th,.ack-box,.btn-secondary,label) { color:var(--lp-ink) !important; }
.lesson-questions.paper-sheet :is(.q-input,.q-table input,.q-table textarea,.q-rating button:not(.selected),.ack-box) { background:var(--lp-bg) !important; color:var(--lp-ink) !important; border-color:var(--lp-border) !important; }
.lesson-questions.paper-sheet :is(.q-input,.q-table input,.q-table textarea)::placeholder { color:var(--lp-ink); opacity:.65; }
.lesson-questions.paper-sheet :is(.q-table td,.q-table th,.assign-part,.assign-controls,.btn-secondary) { border-color:var(--lp-border) !important; }
.lesson-questions.paper-sheet .q-option input { accent-color:var(--lp-accent); }
.lesson-questions.paper-sheet .q-rating button.selected { background:var(--lp-accent); color:var(--lp-bg); border-color:var(--lp-accent); }
.lesson-questions.paper-sheet :is(.q-input,.q-table input,.q-table textarea):focus-visible { outline:2px solid var(--lp-accent); outline-offset:2px; }
@media(max-width:520px) { .lesson-questions { padding:24px 18px !important; } }
.lesson-questions.paper-sheet :is(.mc-prompt,.mc-option) { color:var(--lp-ink); }
.lesson-questions.paper-sheet .mc-option { border-color:var(--lp-border); background:var(--lp-panel); }
.lesson-questions.paper-sheet .mc-option.selected { border:2px solid var(--lp-accent); color:var(--lp-ink); background:var(--lp-bg); font-weight:600; }
.lesson-questions.paper-sheet .mc-option:hover { border-color:var(--lp-accent); }

/* ---- Real paper: a three-hole notebook page (red margin, blue rules, punched holes, page shadow) ---- */
.paper-sheet[data-lesson-theme="notebook"] {
  --lp-line: rgba(70,120,185,.30);
  background-image:
    radial-gradient(circle at 24px 50%, rgba(0,0,0,.30) 0 7px, rgba(0,0,0,.08) 8px, transparent 9px),
    linear-gradient(90deg, transparent 56px, rgba(214,92,92,.62) 56px 58px, transparent 58px),
    repeating-linear-gradient(transparent 0 31px, var(--lp-line) 31px 32px);
  background-size: 48px 33.33%, auto, auto; background-repeat: repeat-y, no-repeat, repeat;
  border-radius: 3px; box-shadow: 0 1px 2px #0002, 4px 5px 0 -2px #efe9da, 4px 5px 0 -1px #cfc6b2, 0 24px 50px -22px #000a;
}
.paper-sheet[data-lesson-theme="notebook"] > .lesson-wrap, .paper-sheet[data-lesson-theme="notebook"] .lesson-wrap.lesson-block { padding-left: 80px !important; }
.paper-sheet[data-lesson-theme="spiral"] {
  --lp-bg:#fffefa; --lp-line: rgba(70,120,185,.28);
  padding-top: 40px;
  background-image:
    radial-gradient(circle at 50% 14px, #2a2a2a 0 4px, #c8c8c8 5px 7px, transparent 8px),
    linear-gradient(90deg, transparent 52px, rgba(214,92,92,.55) 52px 54px, transparent 54px),
    repeating-linear-gradient(transparent 0 31px, var(--lp-line) 31px 32px);
  background-size: 28px 30px, auto, auto; background-repeat: repeat-x, no-repeat, repeat;
  border-radius: 3px 3px 8px 8px; box-shadow: 0 1px 2px #0002, 0 24px 50px -22px #000a;
}
.paper-sheet[data-lesson-theme="spiral"][data-lesson-color="1"] { --lp-bg:#efe2c8; --lp-accent:#6b4a22; }
.paper-sheet[data-lesson-theme="spiral"][data-lesson-color="2"] { --lp-bg:#e8f5ee; --lp-accent:#2e6046; }
.paper-sheet[data-lesson-theme="spiral"] > .lesson-wrap, .paper-sheet[data-lesson-theme="spiral"] .lesson-wrap.lesson-block { padding-left: 76px !important; }
.paper-sheet[data-lesson-theme="composition"] {
  --lp-bg:#fdfcf6; --lp-cover:#1d1d1d; --lp-line: rgba(70,120,185,.28);
  border: 16px solid transparent; border-radius: 4px;
  background:
    linear-gradient(90deg, transparent 50px, rgba(214,92,92,.55) 50px 51px, transparent 51px 54px, rgba(214,92,92,.55) 54px 55px, transparent 55px) padding-box,
    repeating-linear-gradient(transparent 0 31px, var(--lp-line) 31px 32px) padding-box,
    linear-gradient(var(--lp-bg), var(--lp-bg)) padding-box,
    radial-gradient(circle at 30% 40%, #fff 0 1.5px, transparent 2.5px) 0 0 / 9px 11px border-box,
    radial-gradient(circle at 70% 70%, #ffffffb0 0 1px, transparent 2px) 0 0 / 7px 13px border-box,
    radial-gradient(circle at 50% 20%, #ffffff70 0 2px, transparent 3px) 0 0 / 13px 8px border-box,
    linear-gradient(var(--lp-cover), var(--lp-cover)) border-box;
  box-shadow: 0 0 0 1px #000, 0 24px 50px -22px #000a;
}
.paper-sheet[data-lesson-theme="composition"][data-lesson-color="1"] { --lp-bg:#fdfcf6; --lp-cover:#1d3557; --lp-accent:#1d3557; }
.paper-sheet[data-lesson-theme="composition"][data-lesson-color="2"] { --lp-bg:#fdfcf6; --lp-cover:#7a1f1f; --lp-accent:#7a1f1f; }
.paper-sheet[data-lesson-theme="composition"] > .lesson-wrap, .paper-sheet[data-lesson-theme="composition"] .lesson-wrap.lesson-block { padding-left: 74px !important; }
.paper-sheet[data-lesson-theme="legal"] {
  --lp-bg:#fdf5b0; --lp-accent:#6a5512; --lp-line: rgba(80,120,170,.35);
  background-image:
    linear-gradient(#a8923c, #a8923c),
    linear-gradient(90deg, transparent 52px, rgba(205,60,60,.6) 52px 53px, transparent 53px 57px, rgba(205,60,60,.6) 57px 58px, transparent 58px),
    repeating-linear-gradient(transparent 0 31px, var(--lp-line) 31px 32px);
  background-size: 100% 12px, auto, auto; background-repeat: no-repeat, no-repeat, repeat;
  padding-top: 14px; border-radius: 2px; box-shadow: 0 1px 2px #0002, 0 24px 50px -22px #000a;
}
.paper-sheet[data-lesson-theme="legal"][data-lesson-color="1"] { --lp-bg:#fbfbf7; --lp-accent:#4a4a4a; }
.paper-sheet[data-lesson-theme="legal"][data-lesson-color="2"] { --lp-bg:#e9f5dc; --lp-accent:#3c5e24; }
.paper-sheet[data-lesson-theme="legal"] > .lesson-wrap, .paper-sheet[data-lesson-theme="legal"] .lesson-wrap.lesson-block { padding-left: 80px !important; }
.paper-sheet[data-lesson-theme="graph"] {
  --lp-bg:#fbfdff; --lp-accent:#2a5680; --lp-line: rgba(80,140,200,.16);
  background-image: linear-gradient(rgba(80,140,200,.32) 1px, transparent 1px), linear-gradient(90deg, rgba(80,140,200,.32) 1px, transparent 1px), linear-gradient(var(--lp-line) 1px, transparent 1px), linear-gradient(90deg, var(--lp-line) 1px, transparent 1px);
  background-size: 100px 100px, 100px 100px, 20px 20px, 20px 20px; border-radius: 2px;
}
.paper-sheet[data-lesson-theme="graph"][data-lesson-color="1"] { --lp-bg:#eef6e4; --lp-accent:#3c6a2a; }
.paper-sheet[data-lesson-theme="graph"][data-lesson-color="2"] { --lp-bg:#e9f1fb; --lp-accent:#284f86; }
.paper-sheet[data-lesson-theme="index"] {
  --lp-bg:#ffffff; --lp-accent:#9a2f2f;
  background-image: linear-gradient(transparent 16px, rgba(210,80,80,.8) 16px 18px, transparent 18px), repeating-linear-gradient(transparent 0 31px, rgba(110,150,200,.42) 31px 32px);
  background-size: 100% 100%, 100% 100%; background-repeat: no-repeat, repeat-x; background-position: 0 0, 0 18px;
  border-radius: 3px; box-shadow: 0 1px 2px #0002, 0 24px 50px -22px #000a;
}
.paper-sheet[data-lesson-theme="index"][data-lesson-color="1"] { --lp-bg:#eef5ff; --lp-accent:#284f86; }
.paper-sheet[data-lesson-theme="index"][data-lesson-color="2"] { --lp-bg:#fff0f3; --lp-accent:#8a2f4a; }

/* ---- King ---- */
.paper-sheet[data-lesson-theme="decree"] {
  --lp-bg:#f4e4c1; --lp-accent:#7a2a1a;
  background-image:
    url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' width='80' height='60'><path d='M6 50 L14 16 L28 36 L40 8 L52 36 L66 16 L74 50 Z' fill='%23b48a3c' opacity='.55'/><rect x='6' y='50' width='68' height='6' fill='%23b48a3c' opacity='.55'/></svg>"),
    url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' width='80' height='80'><circle cx='40' cy='40' r='34' fill='%239b1c1c'/><circle cx='40' cy='40' r='26' fill='none' stroke='%23c94a4a' stroke-width='3'/><text x='40' y='51' font-size='30' text-anchor='middle' fill='%23f3d7a0'>♔</text></svg>"),
    radial-gradient(ellipse at 50% 50%, transparent 55%, rgba(120,78,28,.32) 100%);
  background-size: 80px 60px, 72px 72px, auto; background-repeat: no-repeat; background-position: 50% 14px, right 22px bottom 22px, 0 0;
  border: 4px double #a87d32; border-radius: 6px; padding-top: 64px; padding-bottom: 80px;
  box-shadow: inset 0 0 50px rgba(120,78,28,.32), 0 24px 50px -22px #000a;
}
.paper-sheet[data-lesson-theme="decree"][data-lesson-color="1"] { --lp-bg:#f8f1e0; --lp-accent:#5c3a14; }
.paper-sheet[data-lesson-theme="decree"][data-lesson-color="2"] { --lp-bg:#ead2a3; --lp-accent:#6b2d16; }
.paper-sheet[data-lesson-theme="throne"] {
  --lp-bg:#f5ecd8; --lp-accent:#4a1a5e; --lp-cover:#3b1450;
  border: 18px solid var(--lp-cover); border-radius: 18px 18px 8px 8px;
  background-image: radial-gradient(ellipse at top, #fffaf0cc, transparent 70%);
  box-shadow: inset 0 0 0 2px #d4af37, inset 0 0 0 6px #d4af3740, 0 0 0 1px #d4af37, 0 24px 50px -22px #000a;
}
.paper-sheet[data-lesson-theme="throne"][data-lesson-color="1"] { --lp-bg:#f6ead9; --lp-accent:#6e1530; --lp-cover:#5a0f24; }
.paper-sheet[data-lesson-theme="throne"][data-lesson-color="2"] { --lp-bg:#eef2e6; --lp-accent:#14503a; --lp-cover:#0f3d2c; }
.paper-sheet[data-lesson-theme="crown"] {
  --lp-bg:#14110a; --lp-accent:#e6c46a;
  background-image: url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' width='90' height='68'><path d='M6 58 L15 18 L31 40 L45 8 L59 40 L75 18 L84 58 Z' fill='%23d4af37' opacity='.14'/></svg>"), radial-gradient(ellipse at top, #d4af3714, transparent 60%);
  background-size: 90px 68px, auto; background-repeat: no-repeat; background-position: right 22px top 18px, 0 0;
  border: 5px double #d4af37; border-radius: 10px;
  box-shadow: 0 0 0 1px #d4af3755, 0 24px 60px -22px #d4af3755;
}
.paper-sheet[data-lesson-theme="crown"][data-lesson-color="1"] { --lp-bg:#101626; --lp-accent:#e9cf86; }
.paper-sheet[data-lesson-theme="crown"][data-lesson-color="2"] { --lp-bg:#22090f; --lp-accent:#f0c987; }

/* ---- Chess ---- */
.paper-sheet[data-lesson-theme="marble"] {
  --lp-bg:#f7f6f2; --lp-accent:#3a3a46;
  border: 14px solid transparent; border-radius: 3px;
  background:
    linear-gradient(115deg, transparent 40%, rgba(150,150,165,.09) 43%, transparent 46%) padding-box,
    linear-gradient(170deg, transparent 70%, rgba(150,150,165,.07) 72%, transparent 74%) padding-box,
    linear-gradient(var(--lp-bg), var(--lp-bg)) padding-box,
    conic-gradient(#3a3a40 25%, #e9e7e2 0 50%, #3a3a40 0 75%, #e9e7e2 0) 0 0 / 28px 28px border-box;
  box-shadow: 0 0 0 1px #9a9aa2, 0 24px 50px -22px #000a;
}
.paper-sheet[data-lesson-theme="marble"][data-lesson-color="1"] { --lp-bg:#ecebe8; --lp-accent:#33343c; }
.paper-sheet[data-lesson-theme="marble"][data-lesson-color="2"] { --lp-bg:#f6ecec; --lp-accent:#6b3340; }
.paper-sheet[data-lesson-theme="tournament"] {
  --lp-bg:#ffffff; --lp-accent:#222;
  background-image:
    url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' width='170' height='30'><text x='0' y='24' font-size='22' fill='%23333' opacity='.55'>♔♕♖♗♘♙</text></svg>"),
    linear-gradient(#222, #222),
    repeating-linear-gradient(transparent 0 31px, rgba(0,0,0,.10) 31px 32px);
  background-size: 170px 30px, 100% 2px, auto; background-repeat: no-repeat, no-repeat, repeat; background-position: right 22px top 12px, 0 50px, 0 52px;
  padding-top: 56px; border: 1px solid #bdbdbd; border-radius: 2px; box-shadow: 0 1px 2px #0002, 0 24px 50px -22px #000a;
}
.paper-sheet[data-lesson-theme="tournament"][data-lesson-color="1"] { --lp-bg:#fbf6e9; --lp-accent:#4a3a1a; }
.paper-sheet[data-lesson-theme="tournament"][data-lesson-color="2"] { --lp-bg:#eef7f1; --lp-accent:#24533a; }
.paper-sheet[data-lesson-theme="checkmate"] {
  --lp-bg:#12100c; --lp-accent:#e6c46a;
  border: 14px solid transparent; border-radius: 3px;
  background:
    url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' width='170' height='30'><text x='0' y='24' font-size='22' fill='%23d4af37' opacity='.35'>♔♕♖♗♘♙</text></svg>") right 20px top 14px / 170px 30px no-repeat padding-box,
    linear-gradient(var(--lp-bg), var(--lp-bg)) padding-box,
    conic-gradient(#d4af37 25%, #1b1812 0 50%, #d4af37 0 75%, #1b1812 0) 0 0 / 28px 28px border-box;
  box-shadow: 0 0 0 1px #d4af37, 0 24px 60px -22px #d4af3740;
}
.paper-sheet[data-lesson-theme="checkmate"][data-lesson-color="1"] { --lp-bg:#111317; --lp-accent:#d9e1ec; }
.paper-sheet[data-lesson-theme="checkmate"][data-lesson-color="2"] { --lp-bg:#160c0e; --lp-accent:#f2a9b4; }
.paper-sheet:is([data-lesson-theme="decree"],[data-lesson-theme="throne"],[data-lesson-theme="crown"],[data-lesson-theme="marble"]) .lesson-block > h2 { font-family:Georgia,serif; text-align:center; border-bottom:3px double var(--lp-accent); padding-bottom:20px; }
.paper-sheet:is([data-lesson-theme="decree"],[data-lesson-theme="throne"]) .lesson-block > p { font-family:Georgia,serif; font-size:18px; line-height:1.9; }

@media(max-width:520px) {
  .paper-sheet:is([data-lesson-theme="notebook"],[data-lesson-theme="spiral"],[data-lesson-theme="composition"],[data-lesson-theme="legal"]) > .lesson-wrap,
  .paper-sheet:is([data-lesson-theme="notebook"],[data-lesson-theme="spiral"],[data-lesson-theme="composition"],[data-lesson-theme="legal"]) .lesson-wrap.lesson-block { padding-left: 62px !important; }
  .paper-sheet[data-lesson-theme="notebook"] { background-size: 34px 33.33%, auto, auto; background-position: -6px 0, -14px 0, 0 0; }
  .paper-sheet[data-lesson-theme="composition"] { border-width: 9px; }
  .paper-sheet:is([data-lesson-theme="marble"],[data-lesson-theme="checkmate"]) { border-width: 8px; }
  .paper-sheet[data-lesson-theme="throne"] { border-width: 9px; }
}

/* ---- The instructor's picker, folded away until opened (students never get it) ---- */
.lesson-look-box { margin: 12px 24px 0; font: 12px/1.5 Inter, Arial, sans-serif; color: var(--lp-ink); }
.lesson-look-box > summary { cursor: pointer; display: inline-flex; align-items: center; min-height: 40px; padding: 6px 14px; border: 1px dashed var(--lp-border); border-radius: 8px; background: var(--lp-panel, #0001); color: var(--lp-accent); font-weight: 600; }
.lesson-look-box > .lesson-look { margin: 8px 0 0; }
.lesson-questions .lesson-look-box { margin: 0 0 20px; }
@media(max-width:520px) { .lesson-look-box { margin-inline: 12px; } }

/* ---- Readability on lined and grid paper ----
   A rule line, margin line or hole must never run through words, checkboxes or answer boxes (on phones the ruled
   lines struck through the text). The decoration stays in the page edges; reading and answers sit on a clean plate
   of paper. Answer boxes get a clear border and a fill that differs from the page on every look. */
.paper-sheet:is([data-lesson-theme="notebook"],[data-lesson-theme="spiral"],[data-lesson-theme="composition"],[data-lesson-theme="legal"],[data-lesson-theme="graph"],[data-lesson-theme="index"],[data-lesson-theme="tournament"],[data-lesson-theme="blueprint"]) { position:relative; isolation:isolate; }
.paper-sheet:is([data-lesson-theme="notebook"],[data-lesson-theme="spiral"],[data-lesson-theme="composition"],[data-lesson-theme="legal"],[data-lesson-theme="graph"],[data-lesson-theme="index"],[data-lesson-theme="tournament"],[data-lesson-theme="blueprint"])::after { content:''; position:absolute; z-index:-1; inset:14px; background:var(--lp-bg); border-radius:3px; pointer-events:none; }
.paper-sheet[data-lesson-theme="spiral"]::after { top:36px; }
.paper-sheet:is([data-lesson-theme="notebook"],[data-lesson-theme="spiral"],[data-lesson-theme="composition"],[data-lesson-theme="legal"]):has(> .lesson-wrap)::after { left:66px; }
@media(max-width:700px) { .paper-sheet:is([data-lesson-theme="notebook"],[data-lesson-theme="spiral"],[data-lesson-theme="composition"],[data-lesson-theme="legal"]):has(> .lesson-wrap)::after { left:12px; } }
.lesson-questions.paper-sheet[data-lesson-theme] :is(.q-input,.q-table input,.q-table textarea) { background:var(--lp-panel) !important; background:color-mix(in srgb, var(--lp-ink) 7%, var(--lp-bg)) !important; border:2px solid var(--lp-ink) !important; border-color:color-mix(in srgb, var(--lp-ink) 50%, transparent) !important; border-radius:8px; }
.lesson-questions.paper-sheet .q-option input:is([type="checkbox"],[type="radio"]) { width:20px; height:20px; flex-shrink:0; }
/* A dark scenario box inside a paper question sheet keeps light words and its own dark answer boxes (the paper's dark ink made its prompts and choices unreadable). */
.lesson-questions.paper-sheet[data-lesson-theme] .scenario-block { --lp-ink:var(--white,#f5f1e7); --lp-bg:var(--panel-solid,#20242d); --lp-panel:rgba(255,255,255,.07); --lp-border:var(--hairline-strong,#777); --lp-accent:var(--gold,#ddbd76); }