/* Stylesheet for the Python interview flashcard app.
   Shares the palette with ../pyinterview/interview.css but has its own
   layout, because this is an app screen rather than a document page. */

:root{
  --bg:#f1f5f9; --panel:#ffffff; --fg:#1f2937; --muted:#64748b; --accent:#2563eb;
  --border:#e2e8f0; --ink:#0f172a; --violet:#7c3aed;
  --good:#16a34a; --bad:#dc2626; --warn:#b45309;
  --shadow:0 10px 30px rgba(15,23,42,.10), 0 2px 6px rgba(15,23,42,.06);
}
*{box-sizing:border-box}
html,body{height:100%}
body{
  margin:0; background:var(--bg); color:var(--fg);
  font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Helvetica,Arial,sans-serif;
  line-height:1.6; font-size:16px;
  display:flex; flex-direction:column;
}
a{color:var(--accent); text-decoration:none}
a:hover{text-decoration:underline}
code{font-family:"SF Mono",ui-monospace,Menlo,Consolas,monospace; font-size:.88em;
     background:#f1f5f9; padding:.08em .35em; border-radius:4px; border:1px solid var(--border)}
strong,b{color:var(--ink)}

/* ---------- top bar ---------- */
header{background:var(--panel); border-bottom:1px solid var(--border); flex:none}
.bar{max-width:1000px; margin:0 auto; padding:12px 20px;
     display:flex; align-items:center; gap:14px; flex-wrap:wrap}
.brand{font-weight:800; font-size:1.05rem; color:var(--ink); letter-spacing:-.01em; margin-right:auto}
.brand span{color:var(--accent)}
.brand small{display:block; font-weight:500; font-size:.72rem; color:var(--muted); letter-spacing:0}

.visually-hidden{position:absolute; width:1px; height:1px; margin:-1px;
                 padding:0; overflow:hidden; clip:rect(0 0 0 0); white-space:nowrap;
                 border:0}

select,button{font:inherit; color:inherit}
select{background:#fff; border:1.5px solid var(--border); border-radius:9px;
       padding:7px 10px; font-size:.88rem; max-width:15em; cursor:pointer}
select:focus-visible,button:focus-visible,.card:focus-visible{
  outline:3px solid #bfdbfe; outline-offset:2px}

.seg{display:flex; border:1.5px solid var(--border); border-radius:9px; overflow:hidden; background:#fff}
.seg button{border:0; background:#fff; padding:7px 13px; font-size:.85rem;
            font-weight:600; color:var(--muted); cursor:pointer}
.seg button[aria-pressed="true"]{background:var(--accent); color:#fff}

/* ---------- filter row ---------- */
.filters{max-width:1000px; margin:0 auto; padding:0 20px 12px;
         display:flex; gap:7px; flex-wrap:wrap; align-items:center}
.chip{border:1.5px solid var(--border); background:#fff; border-radius:999px;
      padding:4px 11px; font-size:.76rem; font-weight:700; cursor:pointer;
      color:var(--muted); letter-spacing:.02em; text-transform:uppercase}
.chip[aria-pressed="true"]{border-color:currentColor}
.chip .n{opacity:.6; font-weight:600; margin-left:.35em}
.chip.t-trigger[aria-pressed="true"]{color:#0e7490; background:#ecfeff}
.chip.t-concept[aria-pressed="true"]{color:#6d28d9; background:#f5f3ff}
.chip.t-idea[aria-pressed="true"]{color:#1d4ed8; background:#eff6ff}
.chip.t-gotcha[aria-pressed="true"]{color:#b91c1c; background:#fef2f2}
.chip.t-tip[aria-pressed="true"]{color:#b45309; background:#fffbeb}
.chip.t-insight[aria-pressed="true"]{color:#047857; background:#ecfdf5}
.chip.t-problem[aria-pressed="true"]{color:#3730a3; background:#eef2ff}
.chip.t-recap[aria-pressed="true"]{color:#9d174d; background:#fdf2f8}
.chip.t-cost[aria-pressed="true"]{color:#334155; background:#f1f5f9}
.chip.ghost{text-transform:none; letter-spacing:0; font-weight:600}

/* ---------- progress ---------- */
.progress{height:4px; background:var(--border)}
.progress i{display:block; height:100%; background:var(--accent); width:0;
            transition:width .25s ease}

/* ---------- stage ---------- */
main{flex:1; display:flex; flex-direction:column; align-items:center;
     justify-content:center; padding:22px 20px; max-width:1000px;
     margin:0 auto; width:100%}

.deckline{color:var(--muted); font-size:.82rem; margin-bottom:10px; text-align:center}
.deckline b{color:var(--ink); font-weight:700}

/* ---------- the card ---------- */
.card{width:100%; max-width:800px; height:min(74vh,660px); perspective:1600px;
      cursor:pointer; border:0; background:none; padding:0; display:block}
.inner{position:relative; width:100%; height:100%; transform-style:preserve-3d;
       transition:transform .45s cubic-bezier(.2,.7,.3,1)}
.card.flipped .inner{transform:rotateY(180deg)}

.face{position:absolute; inset:0; backface-visibility:hidden;
      -webkit-backface-visibility:hidden;
      background:var(--panel); border:1px solid var(--border); border-radius:18px;
      box-shadow:var(--shadow); padding:26px 30px; overflow:hidden; text-align:left;
      display:flex; flex-direction:column}

/* Short cards sit in the middle of the face; long ones scroll inside it,
   so the card never leaves a big empty gap and never overflows. */
.facebody{flex:1; min-height:0; width:100%; overflow-y:auto;
          display:flex; flex-direction:column; justify-content:center}
.facebody > :first-child{margin-top:0}
.face.front{background:var(--panel)}
.face.back{transform:rotateY(180deg); background:#fcfdff}

.meta{display:flex; align-items:center; gap:8px; flex-wrap:wrap;
      font-size:.72rem; margin-bottom:14px; flex:none}
.tag{font-weight:800; letter-spacing:.05em; text-transform:uppercase;
     padding:.2em .65em; border-radius:999px; border:1px solid}
.tag.t-trigger{color:#0e7490; background:#ecfeff; border-color:#a5f3fc}
.tag.t-concept{color:#6d28d9; background:#f5f3ff; border-color:#ddd6fe}
.tag.t-idea{color:#1d4ed8; background:#eff6ff; border-color:#bfdbfe}
.tag.t-gotcha{color:#b91c1c; background:#fef2f2; border-color:#fecaca}
.tag.t-tip{color:#b45309; background:#fffbeb; border-color:#fde68a}
.tag.t-insight{color:#047857; background:#ecfdf5; border-color:#a7f3d0}
.tag.t-problem{color:#3730a3; background:#eef2ff; border-color:#c7d2fe}
.tag.t-recap{color:#9d174d; background:#fdf2f8; border-color:#fbcfe8}
.tag.t-cost{color:#334155; background:#f1f5f9; border-color:#cbd5e1}
.crumb{color:var(--muted)}
.diff{font-weight:800; letter-spacing:.04em; text-transform:uppercase;
      padding:.2em .6em; border-radius:999px; border:1px solid}
.diff.easy{color:#047857; background:#ecfdf5; border-color:#a7f3d0}
.diff.medium{color:#b45309; background:#fffbeb; border-color:#fde68a}
.diff.hard{color:#b91c1c; background:#fef2f2; border-color:#fecaca}
.known-flag{margin-left:auto; color:var(--good); font-weight:700}

.topic{font-size:1.5rem; line-height:1.28; font-weight:750; color:var(--ink);
       letter-spacing:-.015em; margin:0 0 12px}
.setup{font-size:1rem; margin:0 0 14px; color:var(--fg)}
.setup p{margin:.5em 0}
.prompt{font-size:.98rem; color:var(--muted); font-style:italic; margin:0;
        padding-top:12px; border-top:1px dashed var(--border)}
.answer{font-size:1.02rem; margin:0}
.answer ul{padding-left:1.2em; margin:.4em 0}
.answer li{margin:.4em 0}
.answer p{margin:.6em 0}
.blank{display:inline-block; min-width:3.2em; text-align:center;
       background:#fef9c3; border-bottom:2px solid #eab308; border-radius:3px;
       color:#854d0e; font-weight:700}

/* ---------- code on the back ---------- */
.codeblock{margin:14px 0 0}
.codelabel{font-size:.7rem; font-weight:800; letter-spacing:.06em;
           text-transform:uppercase; color:var(--muted); margin-bottom:5px}
.codeblock pre{background:#f8fafc; border:1px solid var(--border); border-radius:10px;
               padding:13px 15px; overflow-x:auto; margin:0; line-height:1.5}
.codeblock code,
code.py{background:none; border:0; padding:0; font-size:.8rem; color:var(--ink);
        white-space:pre; display:block}

/* Python token colours, applied by the highlighter in flash.js. */
.py-kw{color:#7c3aed; font-weight:600}
.py-bi{color:#0891b2}
.py-str{color:#b45309}
.py-cmt{color:#16a34a; font-style:italic}
.py-num{color:#be185d}
.py-fn{color:#1d4ed8; font-weight:600}
.py-dec{color:#9333ea}
.py-self{color:#0f766e; font-style:italic}

.hint{padding-top:14px; margin:10px 0 0; color:var(--muted); font-size:.78rem;
      flex:none; border-top:1px solid var(--border)}
.hint a{font-weight:600}

/* ---------- controls ---------- */
.controls{display:flex; gap:10px; margin-top:18px; flex-wrap:wrap; justify-content:center}
.btn{border:1.5px solid var(--border); background:#fff; border-radius:11px;
     padding:9px 16px; font-size:.9rem; font-weight:700; color:var(--ink);
     cursor:pointer; transition:border-color .15s, transform .1s, background .15s}
.btn:hover{border-color:var(--accent)}
.btn:active{transform:translateY(1px)}
.btn.primary{background:var(--accent); border-color:var(--accent); color:#fff}
.btn.again{color:var(--bad)} .btn.again:hover{border-color:var(--bad); background:#fef2f2}
.btn.got{color:var(--good)} .btn.got:hover{border-color:var(--good); background:#f0fdf4}
.btn kbd{font-family:inherit; font-size:.72rem; opacity:.55; margin-left:.45em;
         border:1px solid currentColor; border-radius:4px; padding:0 .3em}

.empty{text-align:center; color:var(--muted); max-width:520px}
.empty h2{color:var(--ink); font-size:1.3rem; margin:0 0 .4em}

/* ---------- footer ---------- */
footer{flex:none; background:var(--panel); border-top:1px solid var(--border);
       color:var(--muted); font-size:.78rem}
.footinner{max-width:1000px; margin:0 auto; padding:10px 20px;
           display:flex; gap:16px; flex-wrap:wrap; align-items:center}
.keys{margin-left:auto; display:flex; gap:12px; flex-wrap:wrap}
.keys span{white-space:nowrap}
.keys b{font-weight:700; color:var(--ink); border:1px solid var(--border);
        border-radius:4px; padding:0 .35em; background:#f8fafc}

@media (max-width:640px){
  .brand small{display:none}
  .card{height:min(76vh,560px)}
  .codeblock code{font-size:.72rem}
  .face{padding:20px 20px}
  .topic{font-size:1.25rem}
  .keys{display:none}
  .bar{gap:9px; padding:10px 14px}
  select{max-width:11em}
}

/* Respect a user who does not want motion. */
@media (prefers-reduced-motion:reduce){
  .inner{transition:none}
  .progress i{transition:none}
}

/* ---------- grading, one row that drives both schedule and tracking ------ */
.grade{display:flex; gap:8px; flex-wrap:wrap}
.btn.g-again{color:var(--bad)}
.btn.g-again:hover{border-color:var(--bad); background:#fef2f2}
.btn.g-hints{color:var(--warn)}
.btn.g-hints:hover{border-color:var(--warn); background:#fffbeb}
.btn.g-clean{color:var(--good)}
.btn.g-clean:hover{border-color:var(--good); background:#f0fdf4}
.btn.g-fast{color:#6d28d9}
.btn.g-fast:hover{border-color:#6d28d9; background:#f5f3ff}

/* The due counter sits inside its segmented button. */
.seg button b{font-weight:800; margin-left:.3em}

/* ---------- status colours, shared by the badge and the bars ------------- */
.s-none{background:#e2e8f0}
.s-failed{background:#fca5a5}
.s-hints{background:#fcd34d}
.s-clean{background:#86efac}
.s-fast{background:#c4b5fd}

.known-flag{margin-left:auto; font-weight:700; font-size:.68rem;
            padding:.2em .6em; border-radius:999px; color:var(--ink)}
.known-flag.s-failed{background:#fef2f2; color:#b91c1c}
.known-flag.s-hints{background:#fffbeb; color:#b45309}
.known-flag.s-clean{background:#f0fdf4; color:#047857}
.known-flag.s-fast{background:#f5f3ff; color:#6d28d9}

/* ---------- the weak-spot panel ------------------------------------------ */
.panel{width:100%; max-width:900px; background:var(--panel);
       border:1px solid var(--border); border-radius:18px;
       box-shadow:var(--shadow); padding:22px 26px; overflow-x:auto}
.panel h2{margin:0 0 .2em; font-size:1.2rem; color:var(--ink)}
.panelnote{margin:0 0 1em; color:var(--muted); font-size:.85rem}
.panel table{border-collapse:collapse; width:100%; font-size:.83rem}
.panel th,.panel td{border-bottom:1px solid var(--border); padding:7px 9px;
                    text-align:left; white-space:nowrap}
.panel th{color:var(--muted); font-weight:700; font-size:.7rem;
          text-transform:uppercase; letter-spacing:.04em}
.panel td.num,.panel th.num{text-align:right; font-variant-numeric:tabular-nums}
.panel tbody tr:hover{background:#f8fafc}

.statusbar{display:flex; width:130px; height:9px; border-radius:999px;
           overflow:hidden; background:#e2e8f0}
.statusbar i{display:block; height:100%}

@media (max-width:640px){
  .panel{padding:16px 14px}
  .statusbar{width:70px}
}