@font-face{font-family:Haffer;font-weight:400;font-display:swap;src:url(fonts/haffer-regular.woff2) format("woff2")}
@font-face{font-family:Haffer;font-weight:700;font-display:swap;src:url(fonts/haffer-bold.woff2) format("woff2")}

:root{--grey:#E3E1DD;--mauve:#D0B5EF;--em:#25444F;--white:#fff;--max:640px}
*{box-sizing:border-box;margin:0;padding:0}
html{-webkit-text-size-adjust:100%}
body{font-family:Haffer,Arial,sans-serif;color:var(--em);background:var(--white);font-size:17px;line-height:1.45;-webkit-font-smoothing:antialiased;min-height:100vh}
a{color:inherit}
button{font:inherit;color:inherit;cursor:pointer}

/* header */
.top{position:sticky;top:0;z-index:5;background:var(--grey);padding:calc(12px + env(safe-area-inset-top)) 16px 12px}
.bar,.tabs{max-width:var(--max);margin:0 auto}
.bar{display:flex;align-items:center;justify-content:space-between;gap:12px}
.logo img{height:28px;width:auto;display:block}
.tools{display:flex;gap:8px}
.pill{display:inline-flex;align-items:center;justify-content:center;border-radius:999px;border:0;padding:12px 20px;font-weight:700;font-size:16px;line-height:1;text-decoration:none;background:var(--white);white-space:nowrap}
.pill.small{padding:9px 14px;font-size:14px}
.pill.o{background:transparent;box-shadow:inset 0 0 0 2px var(--em)}
.pill.m,.pill.on{background:var(--mauve)}
.tabs{display:flex;gap:8px;margin-top:12px}
.tabs a{flex:1;display:flex;align-items:center;justify-content:center;gap:6px;padding:11px 4px;border-radius:999px;background:var(--white);text-decoration:none;font-size:16px}
.tabs a.on{background:var(--mauve);font-weight:700}
.count{display:inline-block;min-width:22px;padding:3px 6px 2px;border-radius:999px;background:var(--em);color:var(--white);font-size:12px;font-weight:700;text-align:center;line-height:1.2}
.count:empty{display:none}

/* cards */
main{max-width:var(--max);margin:0 auto;padding:0 16px calc(32px + env(safe-area-inset-bottom))}
.hint{font-size:14px;padding:14px 0 0;opacity:.8}
.grid{display:grid;grid-template-columns:1fr;gap:12px;padding-top:12px}
@media (min-width:600px){.grid{grid-template-columns:1fr 1fr}}
.card{position:relative;min-height:128px;border:0;border-radius:24px;display:flex;flex-direction:column;justify-content:center;align-items:center;text-align:center;line-height:1.2;font-size:24px;padding:18px 44px;width:100%;-webkit-tap-highlight-color:transparent;transition:transform .08s}
.card:active{transform:scale(.985)}
.card span+span{margin-top:2px}
.card .long{font-size:19px}
.card.f{background:var(--mauve)}
.card.n{background:var(--grey)}
.card[aria-pressed="true"]{box-shadow:inset 0 0 0 3px var(--em)}
.card[aria-pressed="true"]::after{content:"✓";position:absolute;top:12px;right:14px;width:26px;height:26px;border-radius:50%;background:var(--em);color:var(--white);font-size:15px;display:flex;align-items:center;justify-content:center}
.card:focus-visible{outline:3px solid var(--em);outline-offset:3px}

/* selection */
.sec{font-size:14px;letter-spacing:.06em;text-transform:uppercase;font-weight:700;padding-top:20px}
.empty{padding:32px 4px;text-align:center}
.actions{display:flex;justify-content:center;padding-top:28px}

/* exercises */
.ex{padding-top:8px}
.ex h2{font-size:26px;line-height:1.1;margin:24px 0 12px}
.ex h3{font-size:18px;margin:18px 0 6px}
.ex h4{font-size:16px;margin:14px 0 4px}
.ex p{margin:0 0 10px}
.ex ul{margin:0 0 10px 20px}
.ex li{margin-bottom:6px}
.ex .intro{background:var(--grey);border-radius:24px;padding:4px 20px 12px;margin-top:16px}
.ex .intro h2{margin-top:16px}
.ex details{background:var(--grey);border-radius:24px;margin-bottom:12px;overflow:hidden}
.ex summary{list-style:none;cursor:pointer;padding:18px 52px 18px 20px;font-weight:700;font-size:18px;position:relative}
.ex summary::-webkit-details-marker{display:none}
.ex summary::after{content:"+";position:absolute;right:20px;top:50%;transform:translateY(-50%);font-size:26px;font-weight:400}
.ex details[open] summary::after{content:"–"}
.ex details>*:not(summary){margin-left:20px;margin-right:20px}
.ex details>*:last-child{margin-bottom:20px}
.ex details>ul{margin-left:40px}
.app-note{background:var(--white);border-radius:16px;padding:10px 14px}
.draw{display:grid;gap:12px;justify-items:center;margin:6px 20px 16px;padding:16px;background:var(--white);border-radius:20px}
.draw #drawn{width:100%}
.draw .card{min-height:112px;font-size:22px;pointer-events:none}
.draw .card.n{background:var(--grey)}
.draw .pill{background:var(--mauve)}
.license{font-size:14px;padding:16px 4px 0}
.license p{margin-bottom:10px}