/* Writing Task 1: same look as Statistics 101 and the CLIL handbook site (clil.peopleoftesol.com).
   Friendly classroom app: sticky header, rounded cards, pill tabs. Each lesson owns one hue
   (--c vivid, --cs soft, --ci ink) for its header, tabs and highlights. Slides keep their own design. */
:root {
  --bg: #F6F7FD; --card: #FFFFFF; --ink: #1E2140; --ink-2: #4A4E70; --ink-3: #767A9C;
  --line: #E4E6F3; --line-2: #D2D5EA;
  --pri: #4F5BD5; --pri-s: #E7E9FF; --pri-i: #3A44B8;
  --h1: #FF6B5B; --h1s: #FFE7E3; --h1i: #B83A29;
  --h2: #FF9A1F; --h2s: #FFEFD6; --h2i: #A85700;
  --h3: #F5C400; --h3s: #FFF4C2; --h3i: #806200;
  --h4: #2DB57A; --h4s: #DCF5E8; --h4i: #13734A;
  --h5: #14A8A3; --h5s: #D6F3F1; --h5i: #0A6D69;
  --h6: #2F9BE0; --h6s: #DBEEFB; --h6i: #135F94;
  --h7: #5B6CF0; --h7s: #E4E8FF; --h7i: #3742B2;
  --h8: #9061F0; --h8s: #EFE6FF; --h8i: #5E33BD;
  --h9: #EE4F9A; --h9s: #FDE3EF; --h9i: #A8205F;
  --ok: #13734A; --ok-s: #DCF5E8; --bad: #B83A29; --bad-s: #FFE7E3;
  --shadow: 0 1px 2px rgba(30, 33, 64, .05), 0 8px 24px rgba(30, 33, 64, .07);
  --f-display: "Baloo 2", "Nunito", "Segoe UI", system-ui, sans-serif;
  --f-body: "Nunito", "Segoe UI", system-ui, -apple-system, sans-serif;
  --r: 16px;
  --c: var(--pri); --cs: var(--pri-s); --ci: var(--pri-i);
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #121329; --card: #1C1E38; --ink: #EFF0FF; --ink-2: #C0C3E3; --ink-3: #9094BA;
    --line: #2D3055; --line-2: #3B3F69;
    --pri: #8E98FF; --pri-s: #262A55; --pri-i: #B9C0FF;
    --h1: #FF7E70; --h1s: #3D2226; --h1i: #FFADA3;
    --h2: #FFAC45; --h2s: #3B2A17; --h2i: #FFC983;
    --h3: #F7D23E; --h3s: #38321A; --h3i: #FBE38A;
    --h4: #4CCB91; --h4s: #183326; --h4i: #8FE3BB;
    --h5: #35C2BC; --h5s: #13322F; --h5i: #84E0DB;
    --h6: #55B1EE; --h6s: #16293B; --h6i: #9ED2F6;
    --h7: #7D8BFF; --h7s: #222749; --h7i: #B4BDFF;
    --h8: #A983F7; --h8s: #2B2245; --h8i: #CDB5FF;
    --h9: #F46FAE; --h9s: #3A1F30; --h9i: #F9A8CF;
    --ok: #8FE3BB; --ok-s: #183326; --bad: #FFADA3; --bad-s: #3D2226;
    --shadow: 0 1px 2px rgba(0, 0, 0, .3), 0 8px 24px rgba(0, 0, 0, .28);
    color-scheme: dark;
  }
}
.hue1 { --c: var(--h1); --cs: var(--h1s); --ci: var(--h1i); }
.hue2 { --c: var(--h2); --cs: var(--h2s); --ci: var(--h2i); }
.hue3 { --c: var(--h3); --cs: var(--h3s); --ci: var(--h3i); }
.hue4 { --c: var(--h4); --cs: var(--h4s); --ci: var(--h4i); }
.hue5 { --c: var(--h5); --cs: var(--h5s); --ci: var(--h5i); }
.hue6 { --c: var(--h6); --cs: var(--h6s); --ci: var(--h6i); }
.hue7 { --c: var(--h7); --cs: var(--h7s); --ci: var(--h7i); }
.hue8 { --c: var(--h8); --cs: var(--h8s); --ci: var(--h8i); }
.hue9 { --c: var(--h9); --cs: var(--h9s); --ci: var(--h9i); }

* { box-sizing: border-box; }
[hidden] { display: none !important; }
html { -webkit-text-size-adjust: 100%; }
img { max-width: 100%; }
body { background: var(--bg); color: var(--ink); font: 400 16px/1.6 var(--f-body); margin: 0; }
a { color: var(--ci); }
button, input, select { font: inherit; color: inherit; }
:focus-visible { outline: 3px solid var(--c); outline-offset: 2px; border-radius: 6px; }
h1, h2, h3, h4 { font-family: var(--f-display); font-weight: 700; line-height: 1.15; text-wrap: balance; margin: 0; }
p { margin: 0; }
.wrap { max-width: 1200px; margin: 0 auto; padding-left: max(16px, env(safe-area-inset-left, 0px)); padding-right: max(16px, env(safe-area-inset-right, 0px)); }
.eyebrow { font-size: 12.5px; font-weight: 800; letter-spacing: .06em; text-transform: uppercase; color: var(--ci); }
.muted { color: var(--ink-3); }

/* Header */
.top { position: sticky; top: 0; z-index: 20; background: color-mix(in srgb, var(--card) 94%, transparent); backdrop-filter: blur(8px); border-bottom: 1px solid var(--line); }
.top .wrap { display: flex; align-items: center; gap: 18px; min-height: 64px; }
.brand { display: flex; align-items: center; gap: 10px; text-decoration: none; color: var(--ink); flex-shrink: 0; }
.mark { width: 36px; height: 36px; display: grid; grid-template-columns: 1fr 1fr; gap: 2px; border-radius: 10px; overflow: hidden; transform: rotate(-6deg); }
.mark i { display: grid; place-items: center; font: 800 11px/1 var(--f-display); font-style: normal; color: #fff; }
.mark i:nth-child(1) { background: var(--h6); } .mark i:nth-child(2) { background: var(--h1); }
.mark i:nth-child(3) { background: var(--h3); color: #4A3A00; } .mark i:nth-child(4) { background: var(--h4); }
.brand b { font-family: var(--f-display); font-weight: 800; font-size: 20px; line-height: 1; }
.brand small { display: block; font-size: 12px; color: var(--ink-3); font-weight: 600; margin-top: 2px; }
.nav { display: flex; gap: 4px; overflow-x: auto; scrollbar-width: none; margin-left: auto; }
.nav::-webkit-scrollbar { display: none; }
.nav a { text-decoration: none; color: var(--ink-2); font-weight: 700; font-size: 14.5px; padding: 8px 14px; border-radius: 999px; white-space: nowrap; }
.nav a:hover { background: var(--pri-s); color: var(--pri-i); }
.nav a[aria-current="page"] { background: var(--pri-i); color: var(--card); }
main { padding-block: 28px 72px; min-height: 60vh; }
.foot { border-top: 1px solid var(--line); padding-block: 18px 36px; font-size: 13px; color: var(--ink-3); }
.foot .wrap { display: flex; justify-content: space-between; gap: 16px; flex-wrap: wrap; }
.foot a { color: var(--ink-3); font-weight: 700; }

#adminbar { background: var(--h3s); color: var(--h3i); font-size: 14px; font-weight: 700; padding: 8px 16px; display: flex; gap: 12px; justify-content: center; align-items: center; flex-wrap: wrap; }
#adminbar a { color: var(--h3i); }

/* Controls */
.btn, button.btn { display: inline-flex; align-items: center; gap: 8px; border: 2px solid var(--line-2); background: var(--card); color: var(--ink); padding: 8px 16px; border-radius: 999px; font-size: 14.5px; font-weight: 700; cursor: pointer; text-decoration: none; white-space: nowrap; }
.btn:hover { border-color: var(--ci); color: var(--ci); }
.btn.primary { background: var(--ci); border-color: var(--ci); color: var(--card); }
.btn.primary:hover { filter: brightness(1.1); color: var(--card); }
.btn.sm { padding: 5px 12px; font-size: 13px; }
.btn:disabled { opacity: .45; cursor: default; }
.chip { display: inline-flex; align-items: center; gap: 5px; font-size: 12.5px; font-weight: 800; padding: 3px 10px; border-radius: 999px; background: var(--cs); color: var(--ci); white-space: nowrap; }
.chip.ghost { background: transparent; border: 1.5px dashed var(--line-2); color: var(--ink-3); }
.chip.hid { background: var(--h1s); color: var(--h1i); }
.vis-ctl { display: inline-flex; gap: 6px; align-items: center; vertical-align: middle; margin-left: 8px; }

/* Home */
.hero { display: grid; grid-template-columns: minmax(0, 1.2fr) minmax(0, 1fr); gap: 44px; align-items: center; padding-block: 12px 30px; }
.hero h1 { font-size: clamp(36px, 5.2vw, 58px); font-weight: 800; line-height: 1.05; letter-spacing: -.01em; }
.hero h1 .m1 { background: linear-gradient(transparent 58%, var(--h3s) 58%); color: var(--h1i); padding: 0 2px; border-radius: 4px; }
.hero h1 .m2 { color: var(--h7i); }
.hero .lede { font-size: 18px; color: var(--ink-2); margin-top: 16px; max-width: 54ch; }
.hero .cta { display: flex; gap: 10px; flex-wrap: wrap; margin-top: 22px; }
.stickers { display: flex; gap: 10px; margin-top: 26px; flex-wrap: wrap; }
.stickers span { width: 46px; height: 46px; border-radius: 14px; display: grid; place-items: center; font: 800 22px/1 var(--f-display); background: var(--cs); color: var(--ci); transition: transform .2s; }
.stickers span:nth-child(odd) { transform: rotate(-6deg); } .stickers span:nth-child(even) { transform: rotate(5deg); }
.stickers span:hover { transform: rotate(0) scale(1.12); }
.sample { position: relative; padding: 24px; border-radius: 24px; background: var(--cs); }
.sample .tag { position: absolute; top: -12px; left: 22px; background: var(--ci); color: var(--card); font-size: 12px; font-weight: 800; padding: 4px 12px; border-radius: 999px; }
.sample .cardx { background: var(--card); border-radius: 18px; padding: 20px 22px; box-shadow: var(--shadow); transform: rotate(-1.5deg); }
.sample .q { font-family: var(--f-display); font-size: 22px; font-weight: 700; line-height: 1.25; }
.sample .opts { margin-top: 12px; }
.sample .foot2 { margin-top: 12px; padding-top: 10px; border-top: 2px dashed var(--line); font-size: 14px; color: var(--ink-2); }
.stats { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 12px; margin-top: 10px; }
.stats div { border-radius: var(--r); padding: 14px 16px; background: var(--cs); color: var(--ci); }
.stats b { display: block; font-family: var(--f-display); font-size: 32px; font-weight: 800; line-height: 1; font-variant-numeric: tabular-nums; }
.stats span { font-size: 13.5px; font-weight: 700; }
.sec-head { display: flex; align-items: end; justify-content: space-between; gap: 16px; flex-wrap: wrap; margin: 44px 0 16px; }
.sec-head h2 { font-size: 30px; font-weight: 800; }
.sec-head p { color: var(--ink-2); max-width: 62ch; }
.chapters { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 16px; }
.ch-card { display: grid; grid-template-columns: 64px minmax(0, 1fr); gap: 16px; padding: 18px; background: var(--card); border-radius: 20px; text-decoration: none; color: var(--ink); box-shadow: var(--shadow); border: 2px solid transparent; }
a.ch-card:hover { border-color: var(--c); transform: translateY(-2px); transition: transform .15s; }
.ch-card .no { width: 60px; height: 60px; border-radius: 18px; display: grid; place-items: center; background: var(--cs); color: var(--ci); font: 800 24px/1 var(--f-display); }
.ch-card h3 { font-size: 20px; line-height: 1.25; }
.ch-card .en { color: var(--ci); font-size: 14px; font-weight: 700; margin-top: 2px; }
.ch-card p { font-size: 14.5px; color: var(--ink-2); margin-top: 6px; }
.ch-card .row { display: flex; gap: 6px; flex-wrap: wrap; margin-top: 12px; }
.ch-card.soon { background: transparent; box-shadow: none; border: 2px dashed var(--line-2); }
.ch-card.soon .no { background: var(--line); color: var(--ink-3); }
.ch-card.soon h3 { color: var(--ink-2); }

/* Chapter page */
.crumbs { font-size: 13.5px; color: var(--ink-3); margin-bottom: 10px; display: flex; gap: 6px; flex-wrap: wrap; font-weight: 600; }
.crumbs a { color: var(--ink-3); text-decoration: none; }
.crumbs a:hover { color: var(--ci); text-decoration: underline; }
.chap-head { display: grid; grid-template-columns: auto minmax(0, 1fr); gap: 22px; align-items: start; padding: 24px 26px; border-radius: 26px; background: var(--cs); margin-bottom: 18px; }
.chap-head .big-no { width: clamp(70px, 9vw, 100px); aspect-ratio: 1; border-radius: 26px; display: grid; place-items: center; background: var(--ci); color: var(--card); font: 800 clamp(30px, 4vw, 44px)/1 var(--f-display); transform: rotate(-4deg); }
.chap-head h1 { font-size: clamp(26px, 3.4vw, 38px); font-weight: 800; }
.chap-head .en-title { font-family: var(--f-display); font-size: clamp(16px, 2vw, 20px); color: var(--ci); font-weight: 700; margin-top: 2px; }
.chap-head .summary { margin-top: 10px; color: var(--ink-2); max-width: 72ch; }
.tabs { display: flex; gap: 6px; margin-bottom: 22px; overflow-x: auto; scrollbar-width: none; position: sticky; top: 64px; background: var(--bg); z-index: 5; padding-block: 10px; }
.tabs::-webkit-scrollbar { display: none; }
.tabs a { display: inline-flex; align-items: center; gap: 7px; padding: 9px 15px; text-decoration: none; color: var(--ink-2); font-weight: 800; font-size: 14.5px; white-space: nowrap; border-radius: 999px; background: var(--card); border: 2px solid var(--line); }
.tabs a:hover { border-color: var(--c); color: var(--ci); }
.tabs a[aria-selected="true"] { background: var(--ci); border-color: var(--ci); color: var(--card); }
.tabs a small { font-weight: 700; opacity: .75; }

/* Lesson */
.sheet { background: var(--card); border-radius: 24px; box-shadow: var(--shadow); padding: 30px 36px 34px; }
.sheet section + section { margin-top: 26px; }
.sheet h2 { font-size: 24px; display: flex; align-items: center; gap: 12px; color: var(--ci); margin-bottom: 10px; }
.sheet h2::after { content: ""; flex: 1; height: 3px; border-radius: 3px; background: var(--cs); }
.prose { display: grid; gap: 10px; max-width: 76ch; font-size: 16.5px; line-height: 1.75; }
.prose strong { font-weight: 800; background: linear-gradient(transparent 62%, var(--cs) 62%); }
.sheet .next { margin-top: 28px; }

/* Slides */
.viewer { background: var(--card); border-radius: 22px; box-shadow: var(--shadow); overflow: hidden; }
.viewer .stage { background: #fff; aspect-ratio: 16 / 9; border-bottom: 1px solid var(--line); }
.viewer .stage img { width: 100%; height: 100%; object-fit: contain; display: block; }
.viewer .bar { display: flex; align-items: center; gap: 8px; padding: 12px 14px; flex-wrap: wrap; }
.viewer .bar .grow { flex: 1; }
.viewer .count { font-weight: 800; color: var(--ink-2); font-variant-numeric: tabular-nums; }
.tip { font-size: 13.5px; color: var(--ink-3); margin: 10px 4px 0; font-weight: 600; }
.thumbs { display: grid; grid-template-columns: repeat(auto-fill, minmax(130px, 1fr)); gap: 10px; margin-top: 16px; }
.thumbs button { padding: 0; border: 2px solid transparent; background: var(--card); border-radius: 12px; overflow: hidden; cursor: pointer; box-shadow: var(--shadow); }
.thumbs button.on { border-color: var(--c); }
.thumbs img { width: 100%; display: block; aspect-ratio: 16 / 9; }

/* Exercises */
.ex-intro { font-size: 14.5px; color: var(--ink-2); margin-bottom: 14px; font-weight: 600; }
.exercise { background: var(--card); border-radius: 22px; box-shadow: var(--shadow); padding: 20px 22px; margin-bottom: 18px; scroll-margin-top: 140px; }
.exercise header { display: flex; align-items: center; gap: 12px; flex-wrap: wrap; }
.exercise .exno { width: 42px; height: 42px; border-radius: 13px; display: grid; place-items: center; background: var(--cs); color: var(--ci); font: 800 18px/1 var(--f-display); flex-shrink: 0; }
.exercise h3 { font-size: 21px; }
.instr { font-size: 15px; background: var(--bg); color: var(--ink-2); padding: 10px 14px; border-radius: 14px; margin: 12px 0 6px; }
.instr strong { color: var(--ink); }
.item { display: grid; grid-template-columns: 34px minmax(0, 1fr) auto; gap: 12px; padding: 12px 10px; border-radius: 14px; align-items: start; }
.item + .item { border-top: 1px dashed var(--line); }
.item > * { min-width: 0; }
.item .n { width: 30px; height: 30px; border-radius: 50%; display: grid; place-items: center; background: var(--cs); color: var(--ci); font: 800 14px/1 var(--f-display); }
.item.ok { background: var(--ok-s); } .item.bad { background: var(--bad-s); }
.item .q { font-size: 16px; }
.reveal { grid-column: 2 / 4; font-size: 14.5px; padding: 8px 12px; border-radius: 12px; background: var(--h1s); color: var(--ink); }
.reveal strong { color: var(--h1i); }
.ans-btn { border: 0; cursor: pointer; font-weight: 800; font-size: 13.5px; color: var(--h1i); padding: 4px 12px; border-radius: 999px; background: var(--h1s); white-space: nowrap; }
.ans-btn:hover { background: var(--h1); color: #fff; }
.opts { display: flex; flex-wrap: wrap; gap: 6px; margin-top: 8px; }
.opts button { border: 2px solid var(--line-2); background: var(--card); padding: 6px 14px; border-radius: 999px; font-size: 14.5px; font-weight: 600; cursor: pointer; text-align: left; }
.opts button:hover { border-color: var(--c); }
.opts button .L { font-weight: 800; color: var(--ci); margin-right: 6px; }
.opts button.sel { background: var(--ci); border-color: var(--ci); color: var(--card); }
.opts button.sel .L { color: var(--card); }
input.num, input.blank, select.pick { border: 2px solid var(--line-2); background: var(--bg); border-radius: 12px; padding: 6px 10px; font-size: 15.5px; }
input.num { width: 8em; }
input.blank { width: 9em; padding: 2px 8px; }
select.pick, select.blank { border: 2px solid var(--line-2); background: var(--bg); border-radius: 12px; padding: 4px 8px; font-size: 15px; max-width: 100%; }
input.num:focus, input.blank:focus, select:focus { border-color: var(--c); outline: none; background: var(--card); }
.ok-f { border-color: var(--h4) !important; background: var(--ok-s) !important; }
.bad-f { border-color: var(--h1) !important; background: var(--bad-s) !important; }
.unit { font-size: 14px; color: var(--ink-3); margin-left: 6px; font-weight: 700; }
.field { margin-top: 8px; }
.order { list-style: none; padding: 0; margin: 10px 0 0; display: grid; gap: 6px; }
.order li { display: flex; align-items: center; gap: 10px; padding: 8px 10px; border-radius: 14px; background: var(--bg); }
.order li .pos { width: 28px; height: 28px; border-radius: 50%; display: grid; place-items: center; background: var(--ci); color: var(--card); font: 800 14px/1 var(--f-display); flex-shrink: 0; }
.order li .txt { flex: 1; font-weight: 600; }
.order li.ok { background: var(--ok-s); } .order li.bad { background: var(--bad-s); }
.mv { border: 0; width: 30px; height: 30px; border-radius: 50%; background: var(--card); cursor: pointer; font-weight: 800; color: var(--ci); }
.mv:disabled { opacity: .3; cursor: default; }
.ex-foot { display: flex; gap: 8px; align-items: center; flex-wrap: wrap; margin-top: 14px; padding-top: 14px; border-top: 2px dashed var(--line); }
.score { font-family: var(--f-display); font-size: 18px; font-weight: 800; color: var(--ci); margin-left: 6px; }

/* Admin */
.auth-wrap { display: grid; place-items: start center; padding-block: 20px 40px; }
.auth-card { width: min(460px, 100%); background: var(--card); border-radius: 24px; box-shadow: var(--shadow); padding: 24px 26px; display: grid; gap: 10px; }
.auth-card h1 { font-size: 28px; font-weight: 800; margin-top: 6px; }
.form { display: grid; gap: 6px; margin-top: 6px; }
.form label { font-size: 14px; font-weight: 800; color: var(--ink-2); margin-top: 6px; }
.form input { width: 100%; border: 2px solid var(--line-2); background: var(--bg); border-radius: 12px; padding: 10px 12px; font-size: 15.5px; }
.form input:focus { border-color: var(--c); outline: none; background: var(--card); }
.form .btn.primary { margin-top: 10px; justify-content: center; padding: 11px 16px; }
.form-msg { color: var(--h1i); font-size: 14px; font-weight: 700; min-height: 1em; }
.tbl-wrap { overflow-x: auto; background: var(--card); border-radius: 18px; box-shadow: var(--shadow); }
table { border-collapse: collapse; width: 100%; font-size: 14.5px; }
th, td { text-align: left; vertical-align: middle; padding: 11px 14px; border-top: 1px solid var(--line); }
thead th { border-top: 0; font-size: 12.5px; text-transform: uppercase; letter-spacing: .05em; color: var(--ci); font-weight: 800; background: var(--cs); }
tr.chap td { font-family: var(--f-display); font-size: 17px; font-weight: 700; background: color-mix(in srgb, var(--cs) 50%, transparent); }
td.sub { padding-left: 34px; }

/* ---------- Writing Task 1 additions ---------- */
:root { --s1: #2F9BE0; --s2: #E5533F; --s3: #2DB57A; --s4: #F2A516; --s5: #9061F0; --s6: #14A8A3;
  --mk-y: #FFE45C; --mk-g: #8DE29A; --mk-b: #9ED8FF; }
@media (prefers-color-scheme: dark) { :root:not([data-theme="light"]) { --s1: #55B1EE; --s2: #FF7E70; --s3: #4CCB91; --s4: #FFC046; --s5: #A983F7; --s6: #35C2BC; } }
mark { color: #1E1E1E; padding: 0 3px; border-radius: 3px; }
mark.hl-y { background: var(--mk-y); } mark.hl-g { background: var(--mk-g); } mark.hl-b { background: var(--mk-b); }
mark.hl-r { background: transparent; color: #C62828; font-weight: 800; }
.keyrow { display: flex; gap: 8px; flex-wrap: wrap; font-size: 13.5px; font-weight: 800; margin-top: 8px; }
.part-ctl { margin-bottom: 12px; }
.seg { display: inline-flex; gap: 4px; padding: 4px; border-radius: 999px; background: var(--card); border: 2px solid var(--line); flex-wrap: wrap; }
.seg button { border: 0; background: transparent; padding: 7px 14px; border-radius: 999px; font-weight: 800; font-size: 14px; cursor: pointer; color: var(--ink-2); }
.seg button[aria-pressed="true"] { background: var(--pri-i); color: var(--card); }
.seg button:disabled { cursor: default; opacity: .6; }
.ver-note { color: var(--ink-2); margin: -6px 0 16px; font-weight: 600; }

/* Lesson notes */
.sno { width: 34px; height: 34px; border-radius: 11px; display: inline-grid; place-items: center; background: var(--cs); color: var(--ci); font-size: 17px; flex-shrink: 0; }
.outcomes ul, .remember { margin: 0; padding-left: 22px; display: grid; gap: 6px; font-size: 16.5px; }
.outcomes { background: var(--bg); border-radius: 18px; padding: 16px 20px; }
.outcomes h2::after { display: none; }
.box { margin-top: 14px; border-radius: 16px; padding: 14px 18px; background: var(--cs); max-width: 76ch; }
.box b { display: block; font-family: var(--f-display); font-size: 17px; color: var(--ci); margin-bottom: 4px; }
.box.formula p { font-size: 18px; }
.figs { display: grid; grid-template-columns: repeat(auto-fill, minmax(min(100%, 360px), 1fr)); gap: 14px; margin-top: 16px; align-items: start; }
.fig.sm .tick, .fig.sm .axis-label { font-size: 17px; }
.fig.sm .pie-lab { font-size: 15px; }
.fig { margin: 0; background: var(--card); border: 2px solid var(--line); border-radius: 16px; padding: 12px 14px; }
.fig figcaption { font-family: var(--f-display); font-weight: 700; font-size: 16px; margin-bottom: 6px; }
.fig svg { width: 100%; height: auto; display: block; }
.fig img { display: block; margin: 0 auto; border-radius: 8px; background: #fff; }
.exercise > .fig { margin: 10px 0; max-width: 720px; }
.item .fig.sm, .witem .fig.sm { max-width: 520px; margin-bottom: 8px; }
.fig .grid { stroke: var(--line); stroke-width: 1; }
.fig .tick { fill: var(--ink-3); font-size: 12px; font-family: var(--f-body); font-weight: 600; }
.fig .axis-label { fill: var(--ink-3); font-size: 12px; font-weight: 700; font-family: var(--f-body); }
.fig .pie-lab { fill: #fff; font-size: 13px; font-weight: 800; font-family: var(--f-body); paint-order: stroke; stroke: rgba(0,0,0,.25); stroke-width: 2px; }
.pies { display: flex; gap: 10px; justify-content: center; flex-wrap: wrap; }
.pie { flex: 1 1 140px; max-width: 260px; text-align: center; }
.pie b { font-family: var(--f-display); }
.legend { display: flex; flex-wrap: wrap; gap: 4px 14px; justify-content: center; font-size: 13px; font-weight: 700; color: var(--ink-2); margin-top: 6px; }
.legend i { display: inline-block; width: 12px; height: 12px; border-radius: 3px; margin-right: 6px; vertical-align: -1px; }
.data-wrap { overflow-x: auto; }
table.data { font-size: 14px; }
table.data th, table.data td { padding: 7px 10px; text-align: right; border-top: 1px solid var(--line); }
table.data th:first-child { text-align: left; }
table.data thead th { text-transform: none; letter-spacing: 0; font-size: 13px; background: var(--bg); color: var(--ink-2); vertical-align: bottom; }
.example { margin-top: 16px; border: 2px solid var(--line); border-radius: 18px; padding: 14px 18px; max-width: 80ch; }
.ex-title { font-family: var(--f-display); font-weight: 700; font-size: 17px; color: var(--ci); margin-bottom: 8px; }
.task-box { background: var(--bg); border-left: 4px solid var(--line-2); padding: 10px 14px; border-radius: 4px 12px 12px 4px; font-family: Georgia, "Times New Roman", serif; font-size: 16px; }
.model { margin-top: 10px; font-family: Georgia, "Times New Roman", serif; font-size: 17px; line-height: 1.8; }
.lbl { display: inline-block; font-family: var(--f-body); font-size: 11.5px; font-weight: 800; text-transform: uppercase; letter-spacing: .06em; color: #C62828; margin-right: 10px; }

/* Language */
.lang-head { display: flex; justify-content: space-between; align-items: center; gap: 12px; flex-wrap: wrap; margin-bottom: 12px; }
.lang-head h2 { margin-bottom: 0; }
.toggle { font-size: 14px; font-weight: 700; color: var(--ink-2); display: inline-flex; gap: 8px; align-items: center; cursor: pointer; }
.vocab { display: grid; grid-template-columns: repeat(auto-fill, minmax(260px, 1fr)); gap: 12px; }
.vcard { border: 2px solid var(--line); border-radius: 16px; padding: 12px 14px; }
.vt { display: flex; align-items: center; gap: 8px; }
.vt b { font-family: var(--f-display); font-size: 19px; color: var(--ci); }
.pos { font-size: 12px; font-weight: 800; color: var(--ink-3); font-style: italic; }
.say { margin-left: auto; border: 0; background: var(--cs); color: var(--ci); border-radius: 999px; width: 32px; height: 32px; cursor: pointer; display: grid; place-items: center; flex-shrink: 0; }
.ipa { color: var(--ink-3); font-size: 14px; }
.vi { font-weight: 800; margin-top: 6px; }
.def { font-size: 14.5px; color: var(--ink-2); }
.vex { font-size: 14px; font-style: italic; color: var(--ink-2); margin-top: 4px; }
.hidden-mean .vcard .mean { filter: blur(6px); user-select: none; transition: filter .15s; }
.hidden-mean .vcard { cursor: pointer; }
.hidden-mean .vcard.peek .mean { filter: none; }
.frames { display: grid; gap: 10px; }
.frame { border: 2px solid var(--line); border-radius: 16px; padding: 12px 16px; }
.fen { font-family: Georgia, "Times New Roman", serif; font-size: 17px; }
.fvi { color: var(--ink-2); font-size: 14.5px; margin: 2px 0 6px; }

/* Exercises */
.ex-jump { display: flex; flex-wrap: wrap; gap: 6px; margin-bottom: 16px; }
.ex-jump a { font-size: 13px; font-weight: 700; text-decoration: none; padding: 4px 10px; border-radius: 999px; background: var(--card); border: 1.5px solid var(--line); color: var(--ink-2); }
.ex-jump a:hover { border-color: var(--c); color: var(--ci); }
/* Visual cards: one chart per card, two or three per row */
.exercise.grid .items { display: grid; grid-template-columns: repeat(auto-fill, minmax(min(100%, 330px), 1fr)); gap: 12px; margin-top: 10px; }
.exercise.grid .item { border: 2px solid var(--line); border-top: 2px solid var(--line); grid-template-columns: 30px minmax(0, 1fr); align-content: start; }
.exercise.grid .item > .ctl { grid-column: 2; }
.exercise.grid .reveal { grid-column: 1 / 3; }
.exercise.grid .item .fig.sm { max-width: none; border: 0; padding: 0; }
.exercise.grid .item .fig img { max-height: 230px; width: auto; }
.exercise.grid select.pick { width: 100%; }
.opts.col { flex-direction: column; align-items: stretch; }
.opts.col button { border-radius: 14px; }
.bank { display: grid; grid-template-columns: repeat(auto-fill, minmax(130px, 1fr)); border: 2px solid var(--ink-3); border-radius: 12px; overflow: hidden; margin: 10px 0 4px; }
.bank span { text-align: center; font-weight: 800; font-size: 14.5px; padding: 6px 8px; border-right: 1px solid var(--line); border-bottom: 1px solid var(--line); }
.witem { padding: 12px 4px; }
.witem + .witem { border-top: 1px dashed var(--line); }
.wlabel { font-weight: 800; color: var(--ci); margin-bottom: 6px; }
.witem textarea { width: 100%; margin-top: 8px; border: 2px solid var(--line-2); background: var(--bg); border-radius: 12px; padding: 10px 12px; font: 16px/1.6 Georgia, "Times New Roman", serif; color: var(--ink); resize: vertical; }
.witem textarea:focus { border-color: var(--c); outline: none; background: var(--card); }
.wbar { display: flex; justify-content: space-between; align-items: center; margin-top: 6px; }
.wc { font-size: 13px; color: var(--ink-3); font-weight: 700; }
.witem .reveal { margin-top: 8px; font-family: Georgia, "Times New Roman", serif; font-size: 16px; line-height: 1.7; }
.checklist { display: grid; gap: 4px; margin-top: 10px; padding: 12px 14px; background: var(--bg); border-radius: 14px; font-size: 14.5px; }
.checklist b { font-family: var(--f-display); color: var(--ci); }
.checklist label { display: flex; gap: 8px; align-items: baseline; cursor: pointer; }
tr.ver td { font-family: var(--f-display); font-size: 19px; background: var(--pri-s); }

@media (max-width: 900px) {
  .hero { grid-template-columns: 1fr; gap: 26px; }
  .chapters { grid-template-columns: 1fr; }
  .stats { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}
@media (max-width: 640px) {
  .brand small { display: none; }
  .chap-head { grid-template-columns: 1fr; padding: 20px; }
  .sheet { padding: 22px 18px; }
  .exercise { padding: 16px 14px; }
  .item { grid-template-columns: 30px minmax(0, 1fr); }
  .item > .ctl { grid-column: 2; }
  .reveal { grid-column: 2; }
}