/* Full-screen welcome flow (welcome.js). Built on the theme tokens, so every theme in light and dark gets the same
   neumorphic + pixel look. The pixel font is only for the big card title (24px+ on desktop, 20px+ on phones); everything else is the readable sans font.
   Nothing in this flow scrolls: long lists are paged, and the layout sizes to 100dvh. */
.ob{position:fixed;inset:0;z-index:2000;display:grid;grid-template-rows:auto minmax(0,1fr) auto;height:100vh;height:100dvh;overflow:hidden;color:var(--ink);background:var(--bg);padding:env(safe-area-inset-top) env(safe-area-inset-right) env(safe-area-inset-bottom) env(safe-area-inset-left);font-family:var(--sans)}
body.ob-open{overflow:hidden}
.ob *{box-sizing:border-box}
.ob-sr{position:absolute;width:1px;height:1px;overflow:hidden;clip:rect(0 0 0 0);white-space:nowrap}

/* Backdrop: stepped pixel hills, drifting study motifs and a twinkle field. */
.ob-bg{position:absolute;inset:0;overflow:hidden;pointer-events:none}
.ob-sky{position:absolute;inset:0;background:radial-gradient(ellipse at 20% 0,color-mix(in srgb,var(--accent) 16%,transparent),transparent 55%),radial-gradient(ellipse at 90% 10%,color-mix(in srgb,var(--violet) 14%,transparent),transparent 50%)}
.ob-sky::before{content:"";position:absolute;left:12%;top:18%;width:4px;height:4px;background:var(--gold);opacity:.7;box-shadow:120px 40px 0 var(--accent),260px -6px 0 var(--gold),420px 60px 0 var(--accent),620px 10px 0 var(--gold),780px 70px 0 var(--accent),-60px 130px 0 var(--accent),310px 150px 0 var(--gold),560px 120px 0 var(--accent),900px 24px 0 var(--gold);animation:ob-twinkle 3.6s steps(2,end) infinite}
.ob-hill{position:absolute;left:0;right:0;bottom:0;background:var(--accent)}
.ob-hill-far{height:34%;opacity:.1;clip-path:polygon(0 100%,0 62%,6% 62%,6% 50%,16% 50%,16% 38%,30% 38%,30% 48%,42% 48%,42% 30%,56% 30%,56% 44%,68% 44%,68% 34%,82% 34%,82% 52%,94% 52%,94% 60%,100% 60%,100% 100%)}
.ob-hill-near{height:20%;opacity:.16;background:var(--blue);clip-path:polygon(0 100%,0 56%,10% 56%,10% 40%,22% 40%,22% 58%,38% 58%,38% 44%,52% 44%,52% 62%,66% 62%,66% 42%,80% 42%,80% 56%,92% 56%,92% 46%,100% 46%,100% 100%)}
.ob-float{position:absolute;display:block;opacity:.55;animation:ob-float 7s ease-in-out infinite}
.ob-float svg{display:block}
@keyframes ob-float{0%,100%{transform:translateY(0)}50%{transform:translateY(-14px)}}
@keyframes ob-twinkle{50%{opacity:.25}}

/* Progress: a pixel bar made of blocks plus step dots. */
.ob-top{position:relative;display:flex;align-items:center;gap:16px;padding:14px clamp(16px,4vw,32px) 0;min-width:0}
.ob-progress{flex:1;min-width:0;display:grid;gap:8px}
.ob-bar{display:block;height:14px;background:var(--track);box-shadow:var(--inset-sm);position:relative;overflow:hidden}
.ob-bar i{position:absolute;inset:0 auto 0 0;width:0;background:repeating-linear-gradient(90deg,var(--accent) 0 8px,transparent 8px 10px);transition:width .3s steps(8,end)}
.ob-dots{list-style:none;display:flex;gap:6px;margin:0;padding:0;flex-wrap:wrap}
.ob-dots li{width:10px;height:10px;background:var(--track);box-shadow:var(--inset-sm)}
.ob-dots li.done{background:var(--accent);opacity:.6;box-shadow:none}
.ob-dots li.now{background:var(--gold);box-shadow:0 0 0 2px var(--line)}
.ob-skipall{flex:none;min-height:44px;padding:0 14px;color:var(--muted);background:none;border:0;font:inherit;text-decoration:underline;cursor:pointer}
.ob-skipall:hover{color:var(--ink)}

/* Stage: Lotl and the speech bubble above one big flashcard. */
.ob-stage{position:relative;min-height:0;display:flex;flex-direction:column;align-items:center;gap:10px;padding:10px clamp(16px,4vw,32px) 6px;overflow:hidden}
.ob-guide{flex:none;display:flex;align-items:flex-end;gap:12px;width:min(760px,100%)}
.ob-lotl{flex:none;width:92px}
.ob-lotl-svg{display:block;width:100%;height:auto;animation:ob-bob 4s ease-in-out infinite}
.ob-lotl-big{width:140px;margin:0 auto}
@keyframes ob-bob{50%{transform:translateY(-5px)}}
.ob-bubble{position:relative;margin:0 0 8px;padding:12px 16px;background:var(--bg);color:var(--ink);box-shadow:var(--raise-sm);border-radius:16px;font-size:1rem;line-height:1.45;min-width:0;overflow-wrap:anywhere}
.ob-bubble::before{content:"";position:absolute;left:-8px;bottom:14px;width:14px;height:14px;background:var(--bg);transform:rotate(45deg);box-shadow:-3px 3px 4px -2px var(--sd)}
.ob-slot{position:relative;flex:1 1 auto;min-height:0;width:min(760px,100%);display:flex;perspective:1200px}
.ob-card{flex:1;min-width:0;min-height:0;display:flex;flex-direction:column;gap:8px;padding:clamp(16px,3vw,28px);background:var(--bg);box-shadow:var(--raise);border-radius:24px;overflow:hidden;outline:0}
.ob-title{margin:0;font-family:"Pixelify Sans",var(--sans);font-weight:600;font-size:1.3rem;line-height:1.2;letter-spacing:0;outline:0;overflow-wrap:anywhere}
.ob-hint{margin:0;color:var(--muted);line-height:1.5;overflow-wrap:anywhere}
.ob-hint:empty{display:none}
.ob-sub{margin:10px 0 6px;font-family:var(--sans);font-weight:600;font-size:1rem}
.ob-body{flex:1;min-height:0;display:flex;flex-direction:column;overflow:hidden;padding:6px 4px 6px;margin:0 -4px}
.ob-results{flex:1;min-height:0;display:flex;flex-direction:column;gap:10px}
.ob-card-welcome .ob-body{display:flex;flex-direction:column;justify-content:center}

/* Answer chips: big tap targets. */
.ob-chips{display:grid;grid-template-columns:repeat(auto-fit,minmax(min(100%,210px),1fr));gap:12px}
.ob-chips-courses,.ob-chips-topics{grid-template-columns:repeat(auto-fit,minmax(min(100%,300px),1fr));grid-auto-rows:minmax(0,max-content)}
.ob-chips-year{grid-template-columns:repeat(auto-fit,minmax(min(100%,150px),1fr))}
.ob-chips-sem{grid-template-columns:repeat(auto-fit,minmax(min(100%,160px),1fr))}
.ob-chip{position:relative;display:grid;align-content:center;gap:2px;min-height:56px;width:100%;padding:12px 44px 12px 16px;text-align:left;font:inherit;font-size:1rem;line-height:1.35;color:var(--ink);background:var(--bg);border:0;border-radius:16px;box-shadow:var(--raise-sm);cursor:pointer;overflow-wrap:anywhere;transition:box-shadow .15s,transform .15s}
.ob-chip:hover{transform:translateY(-1px)}
.ob-chip small{color:var(--muted);font-size:.82rem}
.ob-chip::after{content:"";position:absolute;right:14px;top:50%;width:18px;height:18px;margin-top:-9px;background:var(--bg);border:2px solid var(--line)}
.ob-chip[role=radio]::after{border-radius:50%}
.ob-chip[aria-checked=true]{box-shadow:var(--inset-sm),0 0 0 2px var(--accent) inset;background:color-mix(in srgb,var(--accent) 10%,var(--bg))}
.ob-chip[aria-checked=true]::after{background:var(--accent);border-color:var(--accent);box-shadow:inset 0 0 0 3px var(--bg)}
.ob-chip:active{transform:translateY(1px)}
.ob-code{display:inline-block;margin-right:8px;padding:1px 8px;border-radius:999px;background:color-mix(in srgb,var(--accent) 16%,var(--bg));color:var(--ink);font-family:var(--sans);font-weight:600;font-size:.76rem;letter-spacing:.02em;vertical-align:1px}
.ob-course .ob-chip-main{display:flex;align-items:flex-start;gap:8px;min-width:0}
.ob-code{flex:none;margin-right:0}
.ob-ctitle{font-weight:500;min-width:0;display:-webkit-box;-webkit-line-clamp:2;-webkit-box-orient:vertical;overflow:hidden}
.ob-none{margin:0;color:var(--muted)}
.ob-pager{margin-top:auto;display:flex;align-items:center;justify-content:center;gap:12px;flex:none}
.ob-pagebtn{min-height:44px;min-width:84px;padding:0 14px;font:inherit;font-weight:600;color:var(--ink);background:var(--bg);border:0;border-radius:999px;box-shadow:var(--raise-sm);cursor:pointer}
.ob-pagebtn:disabled{opacity:.4;cursor:default;box-shadow:none}
.ob-pageinfo{min-width:56px;text-align:center;color:var(--muted);font-size:.9rem}
.ob-filter{display:block;margin:0 0 12px}
.ob-filter input{width:100%;min-height:44px;padding:0 14px;font:inherit;color:var(--ink);background:var(--bg);border:0;border-radius:12px;box-shadow:var(--inset-sm)}
.ob-list{list-style:none;margin:0 0 12px;padding:0;display:grid;gap:10px}
.ob-list li{display:flex;align-items:center;gap:14px;padding:12px 16px;border-radius:16px;box-shadow:var(--inset-sm);background:var(--bg)}
.ob-list li span{flex:none;display:grid;place-items:center;width:40px}
.ob-link{align-self:flex-start;min-height:44px;padding:0 4px;color:var(--accent);background:none;border:0;font:inherit;text-decoration:underline;cursor:pointer}
.ob-plan{margin:0 0 14px;padding:0;list-style:none;display:grid;gap:10px;counter-reset:ob}
.ob-plan li{position:relative;display:grid;gap:2px;padding:12px 16px 12px 52px;border-radius:16px;box-shadow:var(--raise-sm);counter-increment:ob}
.ob-plan li::before{content:counter(ob);position:absolute;left:14px;top:12px;width:26px;height:26px;display:grid;place-items:center;font-family:var(--sans);font-weight:600;background:var(--accent);color:var(--on-accent)}
.ob-plan small{color:var(--muted);line-height:1.4}
.ob-facts{margin:0;padding:0;list-style:none;display:grid;gap:6px;line-height:1.45}
.ob-facts b{font-weight:600;margin-right:6px}
.ob-creator{flex:1;min-height:min(300px,50vh);position:relative}
.ob-creator-fallback{display:grid;gap:14px;justify-items:center;text-align:center;padding:12px}
.ob-wide .ob-body{display:flex;flex-direction:column;overflow:hidden;padding:0;margin:0}

/* Navigation row. */
.ob-nav{position:relative;display:flex;align-items:center;gap:10px;justify-content:flex-end;width:min(760px,100%);margin:0 auto;padding:10px clamp(16px,4vw,32px) 14px}
.ob-nav .button{min-height:48px;min-width:96px}
.ob-nav [data-ob=back]{margin-right:auto}
.ob-nav button[hidden]{display:none}
.ob-status{flex:1 1 0;min-width:0;text-align:center;color:var(--muted);font-size:.88rem;overflow-wrap:anywhere}
.ob-nav [data-ob=back]+.ob-status{order:0}

/* Card transitions: a soft flip-and-slide between flashcards. */
.ob-in-next{animation:ob-in-next .32s ease-out both}
.ob-in-prev{animation:ob-in-prev .32s ease-out both}
.ob-out-next{animation:ob-out-next .17s ease-in both}
.ob-out-prev{animation:ob-out-prev .17s ease-in both}
@keyframes ob-in-next{from{opacity:0;transform:translateX(48px) rotateY(-14deg)}to{opacity:1;transform:none}}
@keyframes ob-in-prev{from{opacity:0;transform:translateX(-48px) rotateY(14deg)}to{opacity:1;transform:none}}
@keyframes ob-out-next{to{opacity:0;transform:translateX(-48px) rotateY(14deg)}}
@keyframes ob-out-prev{to{opacity:0;transform:translateX(48px) rotateY(-14deg)}}

.ob :focus-visible{outline:3px solid var(--focus);outline-offset:3px}
.ob-title:focus-visible{outline:0}

@media (max-width:600px){
  .ob-lotl{width:64px}.ob-lotl-big{width:110px}
  .ob-bubble{font-size:.94rem;padding:10px 12px}
  .ob-top{gap:8px}
  .ob-nav{gap:8px}.ob-nav .button{min-width:0;padding-inline:16px}
  .ob-chips,.ob-chips-courses,.ob-chips-topics{grid-template-columns:1fr;gap:8px}
  .ob-chips-year{grid-template-columns:1fr 1fr}
  .ob-chips-sem{grid-template-columns:1fr 1fr 1fr}
  .ob-chip{min-height:48px;padding:8px 34px 8px 12px}.ob-chip::after{right:10px;width:16px;height:16px;margin-top:-8px}
  .ob-card{padding:14px;gap:6px;border-radius:20px}
  .ob-title{font-size:1.3rem}.ob-hint{font-size:.92rem;line-height:1.35}
  .ob-guide{display:none}
}
@media (min-width:601px){.ob-title{font-size:clamp(1.5rem,3.4vw,2rem)}}
@media (max-height:660px){
  .ob-guide{display:none}
  .ob-stage{padding-top:6px}
  .ob-hint{font-size:.9rem}
}
@media (max-height:520px){.ob-chip{min-height:44px}.ob-card{padding:10px}}
/* Phone landscape: the card is shorter than its content, so the body scrolls instead of clipping. */
@media (max-height:480px){.ob-body,.ob-wide .ob-body{overflow-y:auto;overscroll-behavior:contain;-webkit-overflow-scrolling:touch}}
@media (prefers-reduced-motion:reduce){
  .ob *,.ob *::before,.ob *::after{animation:none!important;transition:none!important}
}