:root{
  --paper:#f3f4f1; --surface:#ffffff; --ink:#15181d; --ink-2:#4a505a; --line:#d9dcd6;
  --cobalt:#2f4fd8; --cobalt-ink:#ffffff; --cobalt-soft:#e3e8fb;
  --right:#1f8a5b; --wrong:#d1434b; --close:#b7791f;
  --display:"Bricolage Grotesque",ui-sans-serif,system-ui,sans-serif;
  --ui:"Atkinson Hyperlegible",ui-sans-serif,system-ui,sans-serif;
  --r-sm:8px; --r-md:14px; --r-lg:22px;
  --pad:clamp(16px,4vw,40px);
  color-scheme:light dark;
}
@media (prefers-color-scheme:dark){
  :root{--paper:#121417;--surface:#1b1e23;--ink:#eef0ec;--ink-2:#a7adb6;--line:#2d3138;
    --cobalt:#6f88ff;--cobalt-ink:#0d1020;--cobalt-soft:#232b4d;--right:#3fbf86;--wrong:#ff6b72;--close:#e0a84a}
}
*{box-sizing:border-box}
[hidden]{display:none!important}
html{-webkit-text-size-adjust:100%}
body{margin:0;background:var(--paper);color:var(--ink);font:400 17px/1.5 var(--ui);min-height:100dvh;display:flex;flex-direction:column;overflow-x:hidden}
h1,h2{font-family:var(--display);font-weight:650;letter-spacing:-.02em;line-height:1.1;margin:0 0 .4em}
h1{font-size:clamp(30px,5vw,48px)} h2{font-size:clamp(20px,2.4vw,26px)}
p{margin:0 0 .8em}
a{color:inherit}
code{font-size:.92em;background:var(--cobalt-soft);padding:0 .3em;border-radius:4px}
:focus-visible{outline:3px solid var(--cobalt);outline-offset:2px}
.hint{color:var(--ink-2);font-size:15px;max-width:62ch}

/* header */
.bar{display:flex;align-items:center;gap:12px;padding:12px var(--pad);border-bottom:1px solid var(--line);background:var(--paper);position:sticky;top:0;z-index:5}
.brand{display:flex;align-items:center;gap:8px;text-decoration:none;font:650 22px/1 var(--display);letter-spacing:-.02em}
.brand svg{width:24px;height:24px;fill:none;stroke:var(--cobalt);stroke-width:2.4;stroke-linecap:round}
.nav{display:flex;gap:4px;margin-left:8px}
.nav a{text-decoration:none;padding:8px 12px;border-radius:999px;color:var(--ink-2);font-weight:700;font-size:15px}
.nav a[aria-current="page"]{background:var(--ink);color:var(--paper)}
#pro-open{margin-left:auto}
body.pro #pro-open{display:none}

/* buttons */
.btn{appearance:none;border:0;font:700 16px/1 var(--ui);padding:14px 20px;border-radius:999px;cursor:pointer;text-decoration:none;display:inline-flex;align-items:center;justify-content:center;gap:8px;min-height:48px;transition:transform .12s ease,background .15s}
.btn:active{transform:scale(.97)}
.btn:disabled{opacity:.45;cursor:not-allowed}
.btn-primary{background:var(--cobalt);color:var(--cobalt-ink)}
.btn-inverse{background:var(--paper);color:var(--ink)}
.btn-ghost{background:transparent;color:var(--ink);box-shadow:inset 0 0 0 2px var(--line)}
.btn-quiet{background:transparent;color:var(--ink-2);padding:10px 12px;min-height:40px;font-size:15px}
.btn-danger{background:transparent;color:var(--wrong);box-shadow:inset 0 0 0 2px currentColor}
.link{background:none;border:0;padding:0;color:var(--ink-2);font:inherit;font-size:15px;text-decoration:underline;text-underline-offset:3px;cursor:pointer}
.row{display:flex;gap:12px;flex-wrap:wrap;align-items:center}

main{flex:1;width:100%;max-width:1120px;margin:0 auto;padding:clamp(20px,4vw,48px) var(--pad)}
.view{animation:in .22s ease both}
@keyframes in{from{opacity:0;transform:translateY(6px)}}
.section-head{display:flex;align-items:baseline;justify-content:space-between;gap:16px;flex-wrap:wrap;margin-bottom:16px}

/* today */
.today{display:grid;gap:clamp(28px,4vw,44px)}
.queue{display:grid;grid-template-columns:1.6fr 1fr;gap:16px}
.tile{border-radius:var(--r-lg);padding:clamp(20px,3vw,32px);display:flex;flex-direction:column;align-items:flex-start;min-width:0}
.tile-reviews{background:var(--ink);color:var(--paper)}
.tile-lessons{background:var(--surface);box-shadow:inset 0 0 0 1px var(--line)}
.tile-label{font-weight:700;font-size:16px;margin:0}
.tile-count{font:650 clamp(64px,11vw,120px)/.95 var(--display);letter-spacing:-.04em;margin:6px 0 8px;font-variant-numeric:tabular-nums}
.tile-sub{opacity:.75;font-size:15px;margin-bottom:20px}
.tile .btn{margin-top:auto}

.ladder{list-style:none;margin:0;padding:0;display:grid;grid-template-columns:repeat(10,minmax(0,1fr));gap:6px;align-items:end}
.rung{display:flex;flex-direction:column;gap:6px;min-width:0}
.rung-bar{height:var(--h,6px);min-height:6px;border-radius:6px 6px 2px 2px;background:var(--line);transition:height .4s ease}
.rung.has .rung-bar{background:var(--cobalt)}
.rung.mastered.has .rung-bar{background:var(--right)}
.rung-n{font:650 20px/1 var(--display);font-variant-numeric:tabular-nums}
.rung-name{font-size:12px;color:var(--ink-2);line-height:1.2;overflow-wrap:anywhere}
.ladder-legend{display:none}

.forecast{list-style:none;margin:0;padding:0;display:flex;gap:6px;overflow-x:auto;padding-bottom:4px}
.forecast li{flex:0 0 auto;min-width:64px;padding:10px 12px;border-radius:var(--r-sm);background:var(--surface);box-shadow:inset 0 0 0 1px var(--line);font-size:14px;color:var(--ink-2)}
.forecast strong{display:block;font:650 20px/1.1 var(--display);color:var(--ink)}
.forecast .none{color:var(--ink-2);background:none;box-shadow:none;padding:0}

.empty{max-width:640px;padding-top:4vh}
.empty h1{font-size:clamp(34px,6vw,60px)}
.empty p{font-size:19px;color:var(--ink-2);margin-bottom:28px}

/* decks */
.deck-list{list-style:none;margin:0 0 16px;padding:0;display:grid;gap:10px}
.deck{display:grid;grid-template-columns:1fr auto;gap:4px 16px;align-items:center;padding:18px 20px;border-radius:var(--r-md);background:var(--surface);box-shadow:inset 0 0 0 1px var(--line);text-decoration:none}
.deck:hover{box-shadow:inset 0 0 0 2px var(--cobalt)}
.deck-name{font:650 20px/1.2 var(--display);overflow-wrap:anywhere}
.deck-meta{grid-column:1;color:var(--ink-2);font-size:15px}
.deck-due{grid-row:1/3;grid-column:2;font:650 15px/1 var(--ui);padding:8px 12px;border-radius:999px;background:var(--cobalt-soft);color:var(--ink)}
.deck-due.zero{background:transparent;color:var(--ink-2)}

.back{display:inline-block;margin-bottom:16px;color:var(--ink-2);font-weight:700;text-decoration:none}
.back::before{content:"‹ "}
.deck-form{display:grid;gap:20px;max-width:720px}
.field{display:grid;gap:8px}
label{font-weight:700}
input:not([type]),input[type=text],textarea{font:inherit;color:var(--ink);background:var(--surface);border:2px solid var(--line);border-radius:var(--r-sm);padding:12px 14px;width:100%;min-width:0}
textarea{font-size:16px;line-height:1.45;resize:vertical}
input:focus,textarea:focus{border-color:var(--cobalt);outline:none}
.check{display:flex;gap:12px;align-items:flex-start;font-weight:400}
.check input{width:22px;height:22px;margin:2px 0 0;accent-color:var(--cobalt);flex:none}
.file-pick{font-weight:400;color:var(--ink-2);font-size:15px}
.file-pick input{display:block;margin-top:4px;max-width:100%}
.form-msg{min-height:1.5em;margin:0;font-weight:700}
.form-msg.bad{color:var(--wrong)} .form-msg.ok{color:var(--right)}
.cards-wrap{margin-top:40px;max-width:720px}
.card-list{list-style:none;margin:0;padding:0;border-top:1px solid var(--line)}
.card-row{display:grid;grid-template-columns:minmax(0,1fr) minmax(0,1fr) auto;gap:12px;align-items:center;padding:12px 0;border-bottom:1px solid var(--line)}
.card-row .q{font-weight:700;overflow-wrap:anywhere}
.card-row .a{color:var(--ink-2);overflow-wrap:anywhere}
.card-row .stage{font-size:13px;color:var(--ink-2);white-space:nowrap}
.card-row .x{background:none;border:0;color:var(--ink-2);cursor:pointer;font-size:20px;width:36px;height:36px;border-radius:50%}
.card-row .x:hover{color:var(--wrong);background:var(--cobalt-soft)}
.card-row .tail{display:flex;align-items:center;gap:4px}

/* lesson */
.lesson{max-width:640px;margin:0 auto;display:grid;gap:20px}
.lesson-step{color:var(--ink-2);font-weight:700;margin:0}
.lesson-card{background:var(--surface);border-radius:var(--r-lg);box-shadow:inset 0 0 0 1px var(--line);padding:clamp(24px,5vw,48px);text-align:center}
.lesson-q{font:650 clamp(32px,6vw,52px)/1.1 var(--display);letter-spacing:-.02em;overflow-wrap:anywhere}
.lesson-a{font-size:clamp(20px,3vw,26px);color:var(--cobalt);font-weight:700;overflow-wrap:anywhere}
.lesson-note{color:var(--ink-2);margin:0}
.lesson .row{justify-content:space-between}

/* review */
.view-review{max-width:820px;margin:0 auto}
.rv-top{display:flex;align-items:center;justify-content:space-between;gap:8px}
.rv-progress{font-weight:700;font-variant-numeric:tabular-nums}
.rv-acc{color:var(--ink-2);font-weight:400;margin-left:6px}
.rv-meter{height:4px;background:var(--line);border-radius:4px;margin:8px 0 16px;overflow:hidden}
.rv-meter span{display:block;height:100%;width:0;background:var(--right);transition:width .3s ease}
.rv-prompt{background:var(--ink);color:var(--paper);border-radius:var(--r-lg) var(--r-lg) 0 0;padding:clamp(28px,7vw,72px) var(--pad);text-align:center;min-height:clamp(180px,30vh,300px);display:flex;flex-direction:column;justify-content:center}
.rv-prompt.reverse{background:var(--cobalt);color:var(--cobalt-ink)}
.rv-deck{font-size:14px;opacity:.7;margin:0 0 10px}
.rv-q{font:650 clamp(34px,7vw,64px)/1.08 var(--display);letter-spacing:-.025em;margin:0;overflow-wrap:anywhere}
.rv-form{background:var(--surface);border-radius:0 0 var(--r-lg) var(--r-lg);box-shadow:inset 0 0 0 1px var(--line);padding:16px}
.rv-ask{display:block;text-align:center;font-weight:700;color:var(--ink-2);font-size:15px;margin-bottom:10px}
.rv-field{display:flex;border-radius:var(--r-md);background:var(--paper);box-shadow:inset 0 0 0 2px var(--line);transition:background .15s,box-shadow .15s}
.rv-field:focus-within{box-shadow:inset 0 0 0 2px var(--cobalt)}
.rv-field input{flex:1;min-width:0;border:0;background:transparent;font:700 clamp(20px,3.4vw,26px)/1.2 var(--ui);text-align:center;padding:16px 12px;color:var(--ink)}
.rv-field input:focus{outline:none}
.rv-go{flex:none;width:56px;border:0;background:transparent;color:var(--ink-2);cursor:pointer;border-radius:0 var(--r-md) var(--r-md) 0}
.rv-go svg{width:24px;height:24px;fill:none;stroke:currentColor;stroke-width:2.4;stroke-linecap:round;stroke-linejoin:round}
.rv-field.right{background:var(--right);box-shadow:none}
.rv-field.wrong{background:var(--wrong);box-shadow:none}
.rv-field.right input,.rv-field.wrong input,.rv-field.right .rv-go,.rv-field.wrong .rv-go{color:#fff}
.rv-field.shake{animation:shake .35s}
@keyframes shake{20%,60%{transform:translateX(-6px)}40%,80%{transform:translateX(6px)}}
.rv-flash{min-height:1.5em;text-align:center;margin:10px 0 0;font-weight:700;font-size:15px}
.rv-flash.close{color:var(--close)} .rv-flash.bad{color:var(--wrong)} .rv-flash.good{color:var(--right)}
.rv-info{margin-top:16px;padding:20px;border-radius:var(--r-md);background:var(--surface);box-shadow:inset 0 0 0 1px var(--line)}
.rv-info-a{font-size:20px;margin:0 0 6px;overflow-wrap:anywhere}
.rv-info-a span{display:block;font-size:14px;color:var(--ink-2)}
.rv-info-note{color:var(--ink-2);margin:0}

/* done */
.done{max-width:640px}
.done-stats{font-size:19px;color:var(--ink-2)}
.done-list{list-style:none;padding:0;margin:0 0 28px;border-top:1px solid var(--line)}
.done-list li{display:flex;justify-content:space-between;gap:12px;padding:10px 0;border-bottom:1px solid var(--line)}
.done-list .up{color:var(--right);font-weight:700;white-space:nowrap}
.done-list .down{color:var(--wrong);font-weight:700;white-space:nowrap}

/* footer, dialog, toast */
.foot{display:flex;justify-content:space-between;gap:12px;flex-wrap:wrap;padding:20px var(--pad);border-top:1px solid var(--line);color:var(--ink-2);font-size:14px}
.foot p{margin:0}
.foot-actions{display:flex;gap:16px}
.foot-actions .link{font-weight:400}
.pro{border:0;border-radius:var(--r-lg);padding:0;max-width:min(440px,calc(100vw - 32px));background:var(--surface);color:var(--ink)}
.pro::backdrop{background:rgb(10 12 20 / .55)}
.pro-inner{display:grid;gap:12px;padding:28px}
.pro-inner ul{margin:0 0 8px;padding-left:20px}
.pro-inner .link{justify-self:center}
.toast{position:fixed;left:50%;bottom:24px;transform:translate(-50%,20px);opacity:0;background:var(--ink);color:var(--paper);padding:12px 18px;border-radius:14px;width:max-content;font-weight:700;pointer-events:none;transition:.2s;max-width:calc(100vw - 32px);text-align:center;z-index:20}
.toast.on{opacity:1;transform:translate(-50%,0)}

@media (max-width:720px){
  .queue{grid-template-columns:1fr}
  .ladder{grid-template-columns:repeat(5,minmax(0,1fr));row-gap:16px}
  .nav{margin-left:0}
  .nav a{padding:8px 10px}
  .brand span{display:none}
  .card-row{grid-template-columns:minmax(0,1fr) auto}
  .card-row .a{grid-column:1}
  .card-row .tail{grid-row:1/3;grid-column:2}
  .view-review{margin:0 calc(var(--pad) * -1)}
  .rv-top{padding:0 var(--pad)}
  .rv-meter{margin-left:var(--pad);margin-right:var(--pad)}
  .rv-prompt{border-radius:0}
  .rv-form{border-radius:0}
}
@media (prefers-reduced-motion:reduce){
  *,*::before,*::after{animation:none!important;transition:none!important}
}
.foot-made{flex-basis:100%;font-size:13px}