:root {
    --paper: #F6F8FC;
    --grid: #E3E8F2;
    --ink: #18203A;
    --ink-2: #4E5775;
    --ink-3: #858DA8;
    --rule: #CCD4E4;
    --pen: #C1272D;
    --hl: #F3EE5E;
    --hl-ink: #18203A;
    --card: #FFFFFF;
    --card-line: #DCE6F7;
    --margin: #EFB4B7;
    --shadow: 0 1px 0 rgba(24, 32, 58, .06), 0 18px 40px -18px rgba(24, 32, 58, .28);

    --f-display: "Bricolage Grotesque", "Arial Narrow", "Helvetica Neue", Arial, sans-serif;
    --f-body: "Atkinson Hyperlegible Next", "Atkinson Hyperlegible", system-ui, -apple-system, "Segoe UI", sans-serif;
    --f-hand: "Kalam", "Comic Neue", "Segoe Print", "Bradley Hand", cursive;

    --s-14: .875rem; --s-16: 1rem; --s-18: 1.125rem; --s-22: 1.375rem;
    --s-30: 1.875rem; --s-44: clamp(2.25rem, 1.6rem + 2.6vw, 2.75rem);
    --s-64: clamp(2.75rem, 1.6rem + 5vw, 4.25rem);
  }
  @media (prefers-color-scheme: dark) {
    :root:not([data-theme="light"]) {
      --paper: #10152A; --grid: #1A2140; --ink: #ECEFF7; --ink-2: #B2B9CF; --ink-3: #7C85A3;
      --rule: #2C3558; --pen: #FF716B; --hl: #E7DF52; --hl-ink: #10152A; --card: #171D37;
      --card-line: #232B4C; --margin: #5B3044;
      --shadow: 0 1px 0 rgba(0,0,0,.3), 0 18px 40px -18px rgba(0,0,0,.7);
    }
  }
  :root[data-theme="dark"] {
    --paper: #10152A; --grid: #1A2140; --ink: #ECEFF7; --ink-2: #B2B9CF; --ink-3: #7C85A3;
    --rule: #2C3558; --pen: #FF716B; --hl: #E7DF52; --hl-ink: #10152A; --card: #171D37;
    --card-line: #232B4C; --margin: #5B3044;
    --shadow: 0 1px 0 rgba(0,0,0,.3), 0 18px 40px -18px rgba(0,0,0,.7);
  }

  *, *::before, *::after { box-sizing: border-box; }
  body {
    margin: 0;
    background-color: var(--paper);
    background-image:
      linear-gradient(var(--grid) 1px, transparent 1px),
      linear-gradient(90deg, var(--grid) 1px, transparent 1px);
    background-size: 28px 28px;
    background-position: -1px -1px;
    color: var(--ink);
    font-family: var(--f-body);
    font-size: 1.0625rem;
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
    min-height: 100vh;
  }
  @media (min-width: 1000px) {
    body::before {
      content: ""; position: fixed; inset-block: 0; left: 40px; width: 2px;
      background: var(--margin); pointer-events: none; z-index: 0;
    }
  }
  a { color: inherit; }
  /* ---------- 中文 typography ----------
     The display/body webfonts have no CJK glyphs, so /zh/ falls back to the
     platform's Chinese UI face and drops the Latin letter-spacing tightening. */
  :root[lang^="zh"] {
    --f-display: "Bricolage Grotesque", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans SC", sans-serif;
    --f-body: "Atkinson Hyperlegible Next", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans SC", system-ui, sans-serif;
    --f-hand: "Kalam", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", cursive;
  }
  :root[lang^="zh"] {
    /* CJK glyphs are full-width, so the display sizes that fit an English
       headline overflow the same column in 中文. */
    --s-44: clamp(1.9rem, 1.4rem + 2vw, 2.25rem);
    --s-64: clamp(2.25rem, 1.5rem + 3.4vw, 3.25rem);
  }
  :root[lang^="zh"] body { line-height: 1.75; }
  :root[lang^="zh"] h1, :root[lang^="zh"] h2, :root[lang^="zh"] h3 { letter-spacing: 0; line-height: 1.2; }
  :root[lang^="zh"] .c-name { letter-spacing: 0; }
  /* Wide tracking + uppercase are Latin devices; on CJK they just look loose. */
  :root[lang^="zh"] .eyebrow { letter-spacing: .04em; }
  /* `ch` measures the "0" glyph (~half an em here), so every English column cap
     turns into a column half as many characters wide. Re-set them in `em`. */
  :root[lang^="zh"] .hero .lead { max-width: 20em; }
  :root[lang^="zh"] .about .lead { max-width: 20em; }
  :root[lang^="zh"] .about .lead + p { max-width: 31em; }
  :root[lang^="zh"] .contact .lead { max-width: 22em; }
  :root[lang^="zh"] .classes-head .lead { max-width: 31em; }
  :root[lang^="zh"] .cgroup-head p { max-width: 17em; }
  :root[lang^="zh"] .c-blurb { max-width: 32em; }
  :root[lang^="zh"] .c-exam { max-width: 32em; }
  :root[lang^="zh"] .status { max-width: 22em; }
  :root[lang^="zh"] .reviews > p { max-width: 34em; }

  :focus-visible { outline: 3px solid var(--pen); outline-offset: 3px; border-radius: 4px; }
  h1, h2, h3 { font-family: var(--f-display); font-stretch: 82%; line-height: 1.02; letter-spacing: -.02em; margin: 0; text-wrap: balance; color: var(--ink); }
  p { margin: 0; }

  .skip { position: absolute; left: -999px; top: 8px; background: var(--ink); color: var(--paper); padding: 8px 12px; z-index: 50; }
  .skip:focus { left: 16px; }

  .wrap { position: relative; z-index: 1; max-width: 1120px; margin-inline: auto; padding-inline: clamp(16px, 5vw, 72px); }

  /* ---------- header / nav ---------- */
  .top {
    position: sticky; top: 0; z-index: 20;
    background: color-mix(in srgb, var(--paper) 86%, transparent);
    backdrop-filter: blur(8px); -webkit-backdrop-filter: blur(8px);
    border-bottom: 1px solid var(--rule);
  }
  .top .wrap { display: flex; align-items: center; justify-content: space-between; gap: 12px 24px; flex-wrap: wrap; padding-block: 14px; }
  .brand { display: flex; align-items: baseline; gap: 10px; text-decoration: none; }
  .brand b { font-family: var(--f-display); font-stretch: 78%; font-weight: 800; font-size: var(--s-22); letter-spacing: -.02em; }
  .brand span { font-family: var(--f-hand); color: var(--pen); font-size: var(--s-16); transform: rotate(-3deg); display: inline-block; }

  .nav { position: relative; display: flex; gap: 4px; padding: 4px; }
  .nav a {
    position: relative; z-index: 1; text-decoration: none; font-weight: 500; font-size: var(--s-16);
    padding: 6px 14px; border-radius: 3px; color: var(--ink-2); transition: color .25s;
    white-space: nowrap;
  }
  .nav a[aria-current="page"] { color: var(--hl-ink); }
  .nav a:not([aria-current="page"]):hover { color: var(--ink); }
  .nav-hl {
    position: absolute; top: 6px; bottom: 6px; left: 0; width: 0; z-index: 0;
    background: var(--hl); border-radius: 2px 8px 3px 10px / 8px 3px 9px 3px;
    transform: translateX(0) rotate(-1deg);
    transition: transform .5s cubic-bezier(.65,.05,.25,1), width .5s cubic-bezier(.65,.05,.25,1);
  }
  .top-right { display: flex; align-items: center; gap: 10px; }
  .lang {
    font-size: var(--s-14); font-weight: 700; text-decoration: none; white-space: nowrap;
    color: var(--ink-2); background: var(--card); padding: 7px 13px;
    border: 1.5px solid var(--rule); border-radius: 3px 9px 4px 10px / 9px 4px 10px 4px;
    transition: color .2s, border-color .2s, background-color .2s;
  }
  .lang:hover { color: var(--hl-ink); background: var(--hl); border-color: var(--hl-ink); }

  /* On a phone the nav alone fills the row, so the header splits in two:
     brand + language on top, nav across the bottom. `display: contents`
     hoists .nav and .lang into .top .wrap so they can be ordered and wrapped. */
  @media (max-width: 520px) {
    .top .wrap { justify-content: space-between; }
    .top-right { display: contents; }
    .lang { order: 2; }
    .nav { order: 3; width: 100%; justify-content: space-between; }
  }

  /* ---------- page switching ---------- */
  main { padding-block: clamp(32px, 6vw, 72px) 56px; }
  .page.entering .rise { animation: rise .6s cubic-bezier(.2,.7,.2,1) both; animation-delay: calc(var(--i, 0) * 70ms); }
  @keyframes rise { from { opacity: 0; transform: translateY(16px); } to { opacity: 1; transform: none; } }

  .hl {
    color: inherit; padding: 0 .1em; margin: 0 -.05em;
    background: linear-gradient(100deg, transparent 0 1%, var(--hl) 2% 97%, transparent 99%) no-repeat 0 60% / 100% 70%;
    -webkit-box-decoration-break: clone; box-decoration-break: clone;
  }
  .page.entering .hl { animation: swipe .7s .45s cubic-bezier(.6,.1,.3,1) both; }
  .hl { color: var(--hl-ink); }
  @keyframes swipe {
    from { background-size: 0% 70%; color: var(--ink); }
    60% { color: var(--ink); }
    to { background-size: 100% 70%; color: var(--hl-ink); }
  }

  .eyebrow { font-size: var(--s-14); font-weight: 700; letter-spacing: .12em; text-transform: uppercase; color: var(--ink-2); }
  .margin-note { font-family: var(--f-hand); color: var(--pen); font-size: var(--s-18); line-height: 1.2; }

  .btn {
    display: inline-flex; align-items: center; gap: 10px; font: 700 var(--s-16)/1 var(--f-body);
    padding: 15px 22px; border-radius: 4px; text-decoration: none; cursor: pointer; border: 2px solid var(--ink);
    transition: transform .2s, box-shadow .2s, background-color .2s;
  }
  .btn-solid { background: var(--ink); color: var(--paper); box-shadow: 4px 4px 0 var(--pen); }
  .btn-solid:hover { transform: translate(-2px, -2px); box-shadow: 6px 6px 0 var(--pen); }
  .btn-solid:active { transform: translate(2px, 2px); box-shadow: 1px 1px 0 var(--pen); }
  .btn-ghost { background: transparent; color: var(--ink); }
  .btn-ghost:hover { background: var(--hl); color: var(--hl-ink); border-color: var(--hl-ink); }
  .btn svg { width: 18px; height: 18px; transition: transform .2s; }
  .btn:hover svg { transform: translateX(3px); }

  /* ---------- home ---------- */
  .hero { display: grid; grid-template-columns: 1.08fr .92fr; gap: clamp(24px, 4vw, 56px); align-items: center; }
  .hero h1 { font-size: var(--s-64); font-weight: 800; margin-block: 14px 22px; }
  .hero .lead { font-size: var(--s-22); line-height: 1.45; color: var(--ink-2); max-width: 30ch; }
  .hero .actions { display: flex; flex-wrap: wrap; gap: 14px; margin-top: 32px; }
  .doodle-box { position: relative; }
  .doodle { width: 100%; max-width: 100%; height: auto; display: block; overflow: visible; }
  .doodle .axis { fill: none; stroke: var(--ink); stroke-width: 2.5; stroke-linecap: round; stroke-linejoin: round; }
  .doodle .alone { fill: none; stroke: var(--ink-3); stroke-width: 3; stroke-dasharray: 2 10; stroke-linecap: round; }
  .doodle .curve { fill: none; stroke: var(--ink); stroke-width: 5; stroke-linecap: round; stroke-dasharray: 1; stroke-dashoffset: 0; }
  .doodle .ring { fill: none; stroke: var(--pen); stroke-width: 3; stroke-linecap: round; stroke-dasharray: 1; stroke-dashoffset: 0; }
  .doodle .arrow { fill: none; stroke: var(--pen); stroke-width: 2.5; stroke-linecap: round; stroke-linejoin: round; }
  .doodle .dot { fill: var(--hl); stroke: var(--ink); stroke-width: 2.5; transform-box: fill-box; transform-origin: center; }
  .doodle .lbl { fill: var(--ink-2); font: 400 19px var(--f-hand); }
  .doodle .note { fill: var(--pen); font: 700 22px var(--f-hand); }
  .doodle .note-muted { fill: var(--ink-3); font: 400 18px var(--f-hand); }
  .page.entering .doodle .curve { animation: draw 1.5s .35s cubic-bezier(.5,0,.3,1) both; }
  .page.entering .doodle .ring { animation: draw .7s 1.75s ease-out both; }
  .page.entering .doodle .dot { animation: pop .45s 1.7s cubic-bezier(.3,1.6,.5,1) both; }
  .page.entering .doodle .note, .page.entering .doodle .arrow { animation: fade .5s 2.1s both; }
  .page.entering .doodle .alone, .page.entering .doodle .note-muted { animation: fade .6s .2s both; }
  @keyframes draw { from { stroke-dashoffset: 1; } to { stroke-dashoffset: 0; } }
  @keyframes pop { from { transform: scale(0); } to { transform: scale(1); } }
  @keyframes fade { from { opacity: 0; } to { opacity: 1; } }

  .facts { display: grid; grid-template-columns: repeat(3, 1fr); margin: clamp(48px, 8vw, 88px) 0 0; border-top: 2px solid var(--ink); }
  .facts > div { padding: 18px 20px 4px 0; display: grid; gap: 4px; align-content: start; }
  .facts > div + div { padding-left: 20px; border-left: 1px solid var(--rule); }
  .facts dt { font-family: var(--f-hand); color: var(--pen); font-size: var(--s-18); line-height: 1.2; }
  .facts dd { margin: 0; font-family: var(--f-display); font-stretch: 85%; font-weight: 700; font-size: var(--s-30); line-height: 1.1; letter-spacing: -.01em; }
  .facts dd small { display: block; font: 400 var(--s-16)/1.4 var(--f-body); color: var(--ink-2); letter-spacing: 0; margin-top: 4px; }

  .band { margin-top: clamp(56px, 9vw, 104px); display: grid; grid-template-columns: minmax(0, 1fr) auto; gap: 28px 48px; align-items: end; }
  .band h2 { font-size: var(--s-44); font-weight: 800; }
  .band p { color: var(--ink-2); margin-top: 12px; max-width: 52ch; }

  .where { margin-top: clamp(56px, 9vw, 104px); }
  .where > h2 { font-size: var(--s-44); font-weight: 800; }
  .where > p { color: var(--ink-2); margin-top: 12px; max-width: 60ch; }
  .where-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 20px; margin-top: 28px; }
  .where-grid > div { border: 1.5px solid var(--ink); border-radius: 3px; background: var(--card); padding: 22px 24px; }
  .where-grid h3 { font: 700 var(--s-22)/1.2 var(--f-body); }
  .where-grid h3 span { display: block; font: 400 var(--s-18)/1.2 var(--f-hand); color: var(--pen); margin-bottom: 6px; }
  .where-grid p { color: var(--ink-2); margin-top: 10px; }
  @media (max-width: 640px) { .where-grid { grid-template-columns: 1fr; } }

  .reviews { margin-top: clamp(56px, 9vw, 104px); }
  .reviews > h2 { font-size: var(--s-44); font-weight: 800; }
  .reviews > p { color: var(--ink-2); margin-top: 12px; max-width: 60ch; }
  .r-stats { list-style: none; padding: 0; margin: 22px 0 0; display: flex; flex-wrap: wrap; gap: 8px 28px; font: 400 var(--s-18)/1.3 var(--f-hand); color: var(--ink-2); }
  .r-stats b { font: 800 var(--s-30)/1 var(--f-display); color: var(--pen); margin-right: 4px; }
  .q-grid { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 20px; margin: 28px 0 24px; }
  .q { margin: 0; position: relative; display: flex; flex-direction: column; gap: 14px; border: 1.5px solid var(--ink); border-radius: 3px; background: var(--card); padding: 30px 24px 20px; box-shadow: var(--shadow); }
  .q:nth-child(odd) { transform: rotate(-.6deg); }
  .q:nth-child(3n) { transform: rotate(.5deg); }
  .q::before { content: "\201C"; position: absolute; top: -6px; left: 16px; font: 700 3.25rem/1 var(--f-hand); color: var(--pen); }
  .q blockquote { margin: 0; }
  .q blockquote p { font-size: var(--s-18); line-height: 1.5; }
  .q-tr { color: var(--ink-2); font-size: var(--s-16); }
  .q figcaption { margin-top: auto; padding-top: 12px; border-top: 1px dashed var(--rule); font-size: var(--s-14); color: var(--ink-3); }
  @media (max-width: 860px) { .q-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); } }
  @media (max-width: 560px) { .q-grid { grid-template-columns: 1fr; } .q, .q:nth-child(odd), .q:nth-child(3n) { transform: none; } }
  @media (prefers-reduced-motion: reduce) { .q { transform: none !important; } }

  /* ---------- chips / checklist ---------- */
  .chips { list-style: none; margin: 0; padding: 0; display: flex; flex-wrap: wrap; gap: 10px; }
  .chips li {
    font-weight: 500; padding: 8px 14px; border: 1.5px solid var(--ink); border-radius: 3px;
    background: var(--card); transition: transform .2s, background-color .2s, color .2s;
  }
  .chips li:not(.pending):hover { transform: rotate(-2deg) translateY(-2px); background: var(--hl); color: var(--hl-ink); }
  /* chips link into the Classes page; the ::after stretches the link over the whole chip */
  .chips li { position: relative; }
  .chips a { color: inherit; text-decoration: none; }
  .chips a::after { content: ""; position: absolute; inset: 0; }
  .chips a:focus-visible { outline: none; }
  .chips li:has(a:focus-visible) { outline: 3px solid var(--pen); outline-offset: 3px; }

  /* a class opened from a link: clear the sticky header and swipe the highlighter over its name */
  .course { scroll-margin-top: 120px; }
  .course.pulse .c-name {
    color: var(--hl-ink); padding: 0 .1em; margin: 0 -.1em;
    background: linear-gradient(100deg, transparent 0 1%, var(--hl) 2% 97%, transparent 99%) no-repeat 0 60% / 100% 70%;
    animation: swipe .7s .35s cubic-bezier(.6,.1,.3,1) both;
  }
  .pending { border-style: dashed !important; border-color: var(--ink-3) !important; color: var(--ink-3); background: transparent !important; }

  .checks { list-style: none; margin: 0; padding: 0; display: grid; gap: 0; }
  .checks li { display: grid; grid-template-columns: 28px 1fr; gap: 14px; padding: 14px 0; border-bottom: 1px solid var(--rule); align-items: start; }
  .checks li:first-child { border-top: 1px solid var(--rule); }
  .checks svg { width: 26px; height: 26px; stroke: var(--pen); fill: none; stroke-width: 3; stroke-linecap: round; stroke-linejoin: round; margin-top: 1px; }
  .checks b { display: block; font-weight: 700; font-size: var(--s-18); line-height: 1.35; }
  .checks small { display: block; font-size: var(--s-16); color: var(--ink-2); margin-top: 2px; }

  .subject-groups { display: grid; gap: 28px; }
  .sg h3 {
    display: flex; align-items: baseline; gap: 10px; margin-bottom: 12px;
    font: 700 var(--s-14)/1.2 var(--f-body); letter-spacing: .12em; text-transform: uppercase; color: var(--ink-2);
  }
  .sg h3 span { font: 700 var(--s-18)/1 var(--f-hand); letter-spacing: 0; color: var(--pen); }
  .sg .chips li { font-size: var(--s-16); }

  /* ---------- about ---------- */
  .about { display: grid; grid-template-columns: minmax(240px, 340px) minmax(0, 1fr); gap: clamp(32px, 6vw, 80px); align-items: start; }
  .photo {
    position: sticky; top: 100px; background: var(--card); padding: 14px 14px 18px; box-shadow: var(--shadow);
    transform: rotate(-2.5deg); transition: transform .4s cubic-bezier(.3,1.4,.5,1); max-width: 100%;
  }
  .photo:hover { transform: rotate(0deg) scale(1.02); }
  .photo::before {
    content: ""; position: absolute; top: -14px; left: 50%; width: 110px; height: 30px; translate: -50% 0; rotate: 3deg;
    background: color-mix(in srgb, var(--hl) 70%, transparent); border-left: 2px dotted rgba(0,0,0,.08); border-right: 2px dotted rgba(0,0,0,.08);
  }
  .photo-frame {
    aspect-ratio: 4 / 5; max-width: 100%; display: grid; place-items: center; background: var(--grid);
    border: 1.5px dashed var(--ink-3); overflow: hidden;
  }
  .photo-frame img { width: 100%; height: 100%; object-fit: cover; display: block; }
  .photo-frame b { font-family: var(--f-display); font-stretch: 75%; font-weight: 800; font-size: 5.5rem; color: var(--ink-3); letter-spacing: -.04em; }
  .photo figcaption { font-family: var(--f-hand); text-align: center; margin-top: 12px; color: var(--ink-2); font-size: var(--s-18); }

  .about h1 { font-size: var(--s-64); font-weight: 800; margin-block: 12px 24px; }
  .about .lead { font-size: var(--s-22); line-height: 1.5; max-width: 34ch; }
  .about .lead + p { margin-top: 18px; color: var(--ink-2); max-width: 60ch; }
  .block { margin-top: clamp(40px, 6vw, 64px); }
  .block-head { display: flex; align-items: baseline; justify-content: space-between; gap: 8px 16px; flex-wrap: wrap; margin-bottom: 18px; }
  .block h2 { font-size: var(--s-30); font-weight: 800; }

  .quick { display: flex; flex-wrap: wrap; gap: 10px 28px; margin-top: 28px; padding: 0; list-style: none; }
  .quick li { display: flex; gap: 10px; align-items: baseline; font-weight: 500; }
  .quick li::before { content: ""; width: 10px; height: 10px; background: var(--pen); border-radius: 50%; translate: 0 -1px; flex: none; }

  /* ---------- contact ---------- */
  .contact { display: grid; grid-template-columns: minmax(0, .85fr) minmax(0, 1.15fr); gap: clamp(32px, 6vw, 80px); align-items: start; }
  .contact h1 { font-size: var(--s-64); font-weight: 800; margin-block: 12px 20px; }
  .contact .lead { font-size: var(--s-18); color: var(--ink-2); max-width: 40ch; }
  .lines { margin: 36px 0 0; display: grid; }
  .lines > div { display: grid; gap: 2px; padding: 16px 0; border-top: 1px solid var(--rule); }
  .lines > div:last-child { border-bottom: 1px solid var(--rule); }
  .lines dt { font-size: var(--s-14); font-weight: 700; letter-spacing: .12em; text-transform: uppercase; color: var(--ink-3); }
  .lines dd { margin: 0; display: flex; flex-wrap: wrap; align-items: center; gap: 8px 14px; font-size: var(--s-22); font-weight: 500; overflow-wrap: anywhere; }
  .lines dd a { text-decoration-thickness: 2px; text-underline-offset: 4px; text-decoration-color: var(--pen); }
  .lines dd a:hover { background: var(--hl); color: var(--hl-ink); }
  .copy {
    font: 700 var(--s-14)/1 var(--f-body); color: var(--ink-2); background: transparent; border: 1.5px solid var(--rule);
    padding: 7px 10px; border-radius: 3px; cursor: pointer;
  }
  .copy:hover { border-color: var(--ink); color: var(--ink); }
  .lines .pending-text { font-size: var(--s-16); color: var(--ink-3); border: 1.5px dashed var(--ink-3); padding: 3px 10px; border-radius: 3px; }

  /* index card form */
  .card {
    position: relative; background-color: var(--card);
    background-image: linear-gradient(transparent 0 71px, var(--pen) 71px 73px, transparent 73px),
                      repeating-linear-gradient(transparent 0 35px, var(--card-line) 35px 36px);
    background-position: 0 0, 0 73px;
    background-repeat: no-repeat, repeat;
    box-shadow: var(--shadow); padding: 22px clamp(18px, 4vw, 36px) 32px; transform: rotate(.6deg);
  }
  .card-title { height: 50px; display: flex; align-items: center; justify-content: space-between; gap: 12px; }
  .card-title h2 { font-size: var(--s-30); font-weight: 800; }
  .form { display: grid; grid-template-columns: 1fr 1fr; gap: 18px 18px; margin-top: 26px; }
  .field { display: grid; gap: 6px; min-width: 0; }
  .field.full { grid-column: 1 / -1; }
  .field label, .field legend { font-size: var(--s-14); font-weight: 700; color: var(--ink); padding: 0; }
  .field label i { font-style: normal; font-weight: 400; color: var(--ink-3); }
  fieldset.field { border: 0; margin: 0; padding: 0; }
  input[type="text"], input[type="email"], input[type="tel"], select, textarea {
    width: 100%; font: 400 var(--s-16)/1.4 var(--f-body); color: var(--ink); background: var(--paper);
    border: 1.5px solid var(--rule); border-radius: 3px; padding: 11px 12px; transition: border-color .2s, box-shadow .2s;
  }
  textarea { min-height: 128px; resize: vertical; }
  input:focus, select:focus, textarea:focus { outline: none; border-color: var(--ink); box-shadow: 0 0 0 3px color-mix(in srgb, var(--hl) 80%, transparent); }
  input[aria-invalid="true"], textarea[aria-invalid="true"] { border-color: var(--pen); }
  .err { font-family: var(--f-hand); color: var(--pen); font-size: var(--s-16); line-height: 1.2; min-height: 0; }
  .toggle { display: flex; flex-wrap: wrap; gap: 8px; }
  .toggle input { position: absolute; opacity: 0; pointer-events: none; }
  .toggle label {
    font: 500 var(--s-16)/1 var(--f-body); padding: 11px 14px; border: 1.5px solid var(--rule); border-radius: 3px;
    background: var(--paper); cursor: pointer; transition: all .2s;
  }
  .toggle input:checked + label { background: var(--ink); color: var(--paper); border-color: var(--ink); }
  .toggle input:focus-visible + label { outline: 3px solid var(--pen); outline-offset: 2px; }
  .hp { position: absolute; left: -9999px; width: 1px; height: 1px; overflow: hidden; }
  .form-foot { grid-column: 1 / -1; display: flex; flex-wrap: wrap; align-items: center; gap: 14px 20px; margin-top: 6px; }
  .status { font-size: var(--s-16); color: var(--ink-2); max-width: 44ch; }
  .status.ok { color: var(--ink); }
  .status.ok::before { content: "✓ "; color: var(--pen); font-weight: 700; }
  .status.warn { font-family: var(--f-hand); color: var(--pen); font-size: var(--s-18); line-height: 1.25; }
  .btn[disabled] { opacity: .6; cursor: progress; }

  [hidden] { display: none !important; }

  /* ---------- classes ---------- */
  .classes-head h1 { font-size: var(--s-64); font-weight: 800; margin-block: 12px 20px; }
  .classes-head .lead { font-size: var(--s-18); color: var(--ink-2); max-width: 58ch; }

  .filters { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 28px; }
  .filters button {
    display: inline-flex; align-items: baseline; gap: 8px; cursor: pointer;
    font: 500 var(--s-16)/1 var(--f-body); color: var(--ink); background: var(--card);
    border: 1.5px solid var(--rule); border-radius: 3px; padding: 10px 14px;
    transition: background-color .2s, border-color .2s, color .2s;
  }
  .filters button:hover { border-color: var(--ink); }
  .filters button span { font-size: var(--s-14); color: var(--ink-3); font-variant-numeric: tabular-nums; }
  .filters button[aria-pressed="true"] { background: var(--hl); color: var(--hl-ink); border-color: var(--hl-ink); }
  .filters button[aria-pressed="true"] span { color: var(--hl-ink); }

  .catalog { display: grid; gap: clamp(44px, 6vw, 72px); margin-top: clamp(32px, 5vw, 56px); }
  .cgroup { display: grid; grid-template-columns: minmax(200px, 280px) minmax(0, 1fr); gap: 16px clamp(24px, 5vw, 64px); align-items: start; }
  .cgroup.flash { animation: rise .45s cubic-bezier(.2,.7,.2,1) both; }
  .cgroup-head { position: sticky; top: 96px; display: grid; gap: 6px; }
  .cgroup-head h2 { font-size: var(--s-44); font-weight: 800; }
  .cgroup-head p { color: var(--ink-2); font-size: var(--s-16); max-width: 34ch; }

  .courses { border-top: 2px solid var(--ink); }
  .course { border-bottom: 1px solid var(--rule); }
  .course summary {
    list-style: none; cursor: pointer; display: grid; grid-template-columns: minmax(0, 1fr) auto;
    gap: 16px; align-items: start; padding: 18px 4px;
  }
  .course summary::-webkit-details-marker { display: none; }
  .c-main { display: grid; gap: 4px; justify-items: start; }
  .c-name { font-family: var(--f-display); font-stretch: 85%; font-weight: 700; font-size: var(--s-22); line-height: 1.2; letter-spacing: -.01em; }
  .course summary:hover .c-name { text-decoration: underline; text-decoration-color: var(--pen); text-decoration-thickness: 2px; text-underline-offset: 5px; }
  .c-en { font-size: var(--s-14); color: var(--ink-3); letter-spacing: .01em; margin-top: -2px; }
  .c-blurb { color: var(--ink-2); font-size: var(--s-16); max-width: 62ch; }
  .tag {
    margin-top: 6px; font-size: var(--s-14); font-weight: 700; color: var(--ink-2);
    border: 1.5px solid var(--rule); border-radius: 3px; padding: 2px 8px;
  }
  .c-toggle { position: relative; width: 30px; height: 30px; margin-top: 2px; border: 1.5px solid var(--ink); border-radius: 50%; transition: background-color .2s, border-color .2s; }
  .c-toggle::before, .c-toggle::after {
    content: ""; position: absolute; left: 50%; top: 50%; width: 12px; height: 2px;
    background: var(--ink); translate: -50% -50%; transition: rotate .3s;
  }
  .c-toggle::after { rotate: 90deg; }
  .course[open] .c-toggle { background: var(--hl); border-color: var(--hl-ink); }
  .course[open] .c-toggle::before, .course[open] .c-toggle::after { background: var(--hl-ink); }
  .course[open] .c-toggle::after { rotate: 0deg; }

  .c-body { display: grid; gap: 14px; padding: 0 4px 26px; }
  .course[open] .c-body { animation: rise .35s cubic-bezier(.2,.7,.2,1) both; }
  .c-label { font-family: var(--f-hand); color: var(--pen); font-size: var(--s-18); line-height: 1; }
  .topics { list-style: none; margin: 0; padding: 0; columns: 2 17rem; column-gap: 32px; }
  .topics li { position: relative; break-inside: avoid; padding: 4px 0 4px 22px; font-size: var(--s-16); }
  .topics li::before { content: ""; position: absolute; left: 2px; top: .95em; width: 11px; height: 2px; background: var(--pen); rotate: -8deg; }
  .c-exam { font-size: var(--s-16); color: var(--ink-2); max-width: 64ch; }

  .ask {
    justify-self: start; display: inline-flex; align-items: center; gap: 8px; cursor: pointer;
    font: 700 var(--s-16)/1.2 var(--f-body); color: var(--ink); background: transparent; border: 0; padding: 6px 2px;
    text-decoration: underline; text-decoration-color: var(--pen); text-decoration-thickness: 2px; text-underline-offset: 5px;
  }
  .ask:hover { background: var(--hl); color: var(--hl-ink); }
  .ask svg { width: 16px; height: 16px; flex: none; transition: transform .2s; }
  .ask:hover svg { transform: translateX(3px); }

  @media (max-width: 860px) {
    .cgroup { grid-template-columns: 1fr; }
    .cgroup-head { position: static; }
  }
  @media (max-width: 520px) {
    .nav a { padding: 6px 9px; }
  }
  /* Four English nav items still don't fit a 320px phone at full size. */
  @media (max-width: 380px) {
    .nav a { padding: 6px 5px; font-size: var(--s-14); }
    .lang { padding: 6px 10px; }
  }

  /* ---------- footer ---------- */
  footer { border-top: 1px solid var(--rule); padding-block: 26px 36px; font-size: var(--s-14); color: var(--ink-3); position: relative; z-index: 1; }
  footer .wrap { display: flex; flex-wrap: wrap; gap: 8px 24px; justify-content: space-between; }
  footer a { color: var(--ink-2); }

  .toast {
    position: fixed; left: 50%; bottom: 24px; translate: -50% 20px; opacity: 0; z-index: 60;
    background: var(--ink); color: var(--paper); padding: 10px 16px; border-radius: 4px; font-weight: 500;
    transition: opacity .25s, translate .25s; pointer-events: none;
  }
  .toast.show { opacity: 1; translate: -50% 0; }

  @media (max-width: 860px) {
    .hero, .about, .contact { grid-template-columns: 1fr; }
    .doodle-box { max-width: 520px; }
    .photo { position: relative; top: 0; width: min(300px, 100%); margin-inline: auto; }
    .band { grid-template-columns: 1fr; }
    .card { transform: none; }
  }
  @media (max-width: 640px) {
    .facts { grid-template-columns: 1fr; }
    .facts > div, .facts > div + div { padding: 14px 0; border-left: 0; }
    .facts > div + div { border-top: 1px solid var(--rule); }
    .form { grid-template-columns: 1fr; }
    .hero .lead { font-size: var(--s-18); }
  }
  @media (prefers-reduced-motion: reduce) {
    *, *::before, *::after { animation-duration: .001ms !important; animation-delay: 0s !important; transition-duration: .001ms !important; }
  }