/* DSA Compass — dark, thumb-first, same family as PatternFeed. */

:root{
  --bg:#08080c; --bg-soft:#0f0f17; --card:#14141f; --card-2:#1a1a28;
  --line:rgba(255,255,255,.08); --line-2:rgba(255,255,255,.15);
  --txt:#f3f3f8; --dim:#a8a8bd; --faint:#6c6c84;
  --accent:#7c5cff; --accent-2:#ff4d94; --cyan:#3ec8ff;
  --ok:#2fd8a0; --warn:#ffb547; --bad:#ff5f6d;
  --code-bg:#0b0b13;
  --r-lg:20px; --r-md:14px; --r-sm:10px;
  --safe-t:env(safe-area-inset-top,0px); --safe-b:env(safe-area-inset-bottom,0px);
  --tabh:62px;
  --ff:ui-sans-serif,-apple-system,"Segoe UI",Roboto,"Helvetica Neue",Arial,sans-serif;
  --mono:ui-monospace,"SF Mono","Cascadia Mono",Menlo,Consolas,monospace;
}
*{box-sizing:border-box;-webkit-tap-highlight-color:transparent}
html,body{height:100%;margin:0}
body{background:var(--bg);color:var(--txt);font:15px/1.5 var(--ff);-webkit-font-smoothing:antialiased;overscroll-behavior:none}
button,input,textarea,select{font:inherit;color:inherit}
button{border:0;background:none;cursor:pointer;padding:0}
h1,h2,h3,h4,p{margin:0}
a{color:inherit}
a.card,a.chip,a.btn,a.pill,a.back,a.topic-row{text-decoration:none;color:inherit}
a.card{display:block}
a.pill.v-ok{color:var(--ok)} a.pill.v-warn{color:var(--warn)} a.pill.v-bug{color:var(--bad)}
.splash{position:fixed;inset:0;z-index:100;display:grid;place-items:center;background:radial-gradient(120% 90% at 50% 0%,#231a4d 0%,#0b0b12 55%,#08080c 100%);transition:opacity .4s,visibility .4s}
.splash.gone{opacity:0;visibility:hidden}
.splash h1{font-size:28px;font-weight:800;letter-spacing:-.5px}
.splash p{color:var(--faint);font-size:13px;text-align:center;margin-top:4px}
[hidden]{display:none!important}
code{font-family:var(--mono);font-size:.88em;background:rgba(255,255,255,.07);padding:1px 5px;border-radius:6px}

/* ---------- frame ---------- */
#view{position:fixed;inset:0;overflow-y:auto;overflow-x:hidden;-webkit-overflow-scrolling:touch;
  padding:calc(var(--safe-t) + 12px) 14px calc(var(--tabh) + var(--safe-b) + 28px)}
.wrap{max-width:760px;margin:0 auto}
.tabbar{position:fixed;left:0;right:0;bottom:0;z-index:40;display:flex;
  height:calc(var(--tabh) + var(--safe-b));padding-bottom:var(--safe-b);
  background:rgba(10,10,16,.86);backdrop-filter:blur(18px);border-top:1px solid var(--line)}
.tab{text-decoration:none;flex:1;display:flex;flex-direction:column;align-items:center;justify-content:center;gap:2px;color:var(--faint);font-size:11px;font-weight:600}
.tab i{font-style:normal;font-size:19px;line-height:1}
.tab.on{color:var(--txt)}
.tab.on i{background:linear-gradient(135deg,var(--accent),var(--accent-2));-webkit-background-clip:text;background-clip:text;color:transparent}

/* ---------- headings ---------- */
.hero{padding:10px 2px 8px}
.hero h1{font-size:27px;font-weight:800;letter-spacing:-.5px}
.hero h1 span{background:linear-gradient(90deg,var(--accent),var(--accent-2));-webkit-background-clip:text;background-clip:text;color:transparent}
.hero p{color:var(--dim);font-size:13.5px;margin-top:3px}
.h2{font-size:21px;font-weight:800;letter-spacing:-.3px;margin:6px 2px 10px}
.sec{font-size:12px;font-weight:750;letter-spacing:.9px;text-transform:uppercase;color:var(--faint);margin:22px 2px 9px}
.sub{color:var(--dim);font-size:13.5px}
.back{display:inline-flex;align-items:center;gap:6px;color:var(--dim);font-size:14px;font-weight:600;padding:6px 2px 10px}

/* ---------- search ---------- */
.qbox{position:relative;margin:10px 0 8px}
.qbox textarea{width:100%;min-height:92px;resize:vertical;border-radius:var(--r-lg);border:1px solid var(--line-2);
  background:var(--card);padding:14px 44px 14px 15px;font-size:15.5px;line-height:1.45;outline:none}
.qbox textarea:focus{border-color:rgba(124,92,255,.7);box-shadow:0 0 0 4px rgba(124,92,255,.14)}
.qbox .clear{position:absolute;right:10px;top:10px;width:30px;height:30px;border-radius:99px;background:rgba(255,255,255,.08);color:var(--dim)}
.input{width:100%;border-radius:var(--r-md);border:1px solid var(--line-2);background:var(--card);padding:11px 13px;font-size:15px;outline:none}
.input:focus{border-color:rgba(124,92,255,.7)}
.chips{display:flex;flex-wrap:wrap;gap:7px}
.chips.scroll{flex-wrap:nowrap;overflow-x:auto;scrollbar-width:none;margin:0 -14px;padding:2px 14px}
.chips.scroll::-webkit-scrollbar{display:none}
.chip{flex:none;display:inline-flex;align-items:center;gap:6px;padding:6px 12px;border-radius:99px;font-size:13px;font-weight:600;
  background:rgba(255,255,255,.06);border:1px solid var(--line);color:var(--dim);white-space:nowrap}
.chip.on{background:linear-gradient(135deg,rgba(124,92,255,.35),rgba(255,77,148,.25));border-color:rgba(124,92,255,.6);color:var(--txt)}
.chip.sm{padding:3px 9px;font-size:12px}
.chip.pat{color:#cfc5ff;border-color:rgba(124,92,255,.35);background:rgba(124,92,255,.1)}

/* ---------- cards ---------- */
.card{background:var(--card);border:1px solid var(--line);border-radius:var(--r-lg);padding:15px 15px 14px;margin-bottom:10px}
.card.tap{cursor:pointer;transition:transform .12s ease,border-color .12s}
.card.tap:active{transform:scale(.985)}
.card h3{font-size:16.5px;font-weight:750;letter-spacing:-.15px}
.card .meta{display:flex;flex-wrap:wrap;gap:6px;align-items:center;margin-top:6px;color:var(--faint);font-size:12.5px}
.card p{color:var(--dim);font-size:14px;margin-top:6px}
.glow{border-color:rgba(124,92,255,.45);background:linear-gradient(160deg,rgba(124,92,255,.14),rgba(255,77,148,.06) 60%,var(--card))}
.row{display:flex;align-items:center;gap:10px}
.row.between{justify-content:space-between}
.grow{flex:1;min-width:0}
.grid2{display:grid;grid-template-columns:1fr 1fr;gap:10px}
@media (min-width:640px){.grid3{display:grid;grid-template-columns:repeat(3,1fr);gap:10px}}

.pill{display:inline-flex;align-items:center;gap:4px;font-size:11.5px;font-weight:700;padding:2px 8px;border-radius:99px;letter-spacing:.2px}
.d-E{color:var(--ok);background:rgba(47,216,160,.12)}
.d-M{color:var(--warn);background:rgba(255,181,71,.12)}
.d-H{color:var(--bad);background:rgba(255,95,109,.12)}
.v-ok{color:var(--ok);background:rgba(47,216,160,.12)}
.v-warn{color:var(--warn);background:rgba(255,181,71,.13)}
.v-bug{color:var(--bad);background:rgba(255,95,109,.13)}
.v-mine{color:#cfc5ff;background:rgba(124,92,255,.16)}
.s-exact{color:var(--ok);background:rgba(47,216,160,.12)}
.s-strong{color:var(--cyan);background:rgba(62,200,255,.12)}
.s-close{color:var(--warn);background:rgba(255,181,71,.12)}
.s-loose{color:var(--faint);background:rgba(255,255,255,.06)}

.why{font-size:12.5px;color:var(--faint);margin-top:7px}
.why b{color:var(--dim);font-weight:600}
.bar{height:4px;border-radius:99px;background:rgba(255,255,255,.07);overflow:hidden;margin-top:9px}
.bar > i{display:block;height:100%;background:linear-gradient(90deg,var(--accent),var(--accent-2));border-radius:99px}

/* ---------- lists ---------- */
.list{list-style:none;margin:8px 0 0;padding:0}
.list li{position:relative;padding:7px 0 7px 22px;color:var(--dim);font-size:14.5px;border-top:1px solid var(--line)}
.list li:first-child{border-top:0}
.list li::before{content:"";position:absolute;left:5px;top:15px;width:6px;height:6px;border-radius:99px;background:var(--accent)}
.list.warn li::before{background:var(--warn)}
.list.bad li::before{background:var(--bad)}
.list.ok li::before{background:var(--ok)}
ol.steps{counter-reset:s;list-style:none;margin:8px 0 0;padding:0}
ol.steps li{counter-increment:s;position:relative;padding:8px 0 8px 36px;color:var(--txt);font-size:14.5px;border-top:1px solid var(--line)}
ol.steps li:first-child{border-top:0}
ol.steps li::before{content:counter(s);position:absolute;left:0;top:7px;width:24px;height:24px;border-radius:8px;display:grid;place-items:center;
  font-size:12.5px;font-weight:800;background:rgba(124,92,255,.18);color:#cfc5ff}

/* ---------- problem page ---------- */
.ptitle{font-size:23px;font-weight:800;letter-spacing:-.4px;line-height:1.2}
.seg{display:flex;gap:4px;padding:4px;background:var(--bg-soft);border:1px solid var(--line);border-radius:14px;margin:14px 0 12px;position:sticky;top:-12px;z-index:5}
.seg button{flex:1;padding:8px 4px;border-radius:10px;font-size:13.5px;font-weight:700;color:var(--faint)}
.seg button.on{background:var(--card-2);color:var(--txt);box-shadow:0 1px 0 rgba(255,255,255,.06) inset}
.qtext{font-size:15.5px;line-height:1.55}
.ex{font-family:var(--mono);font-size:13px;color:var(--dim);background:var(--code-bg);border:1px solid var(--line);border-radius:12px;padding:9px 11px;margin-top:8px;white-space:pre-wrap}
.hint{border:1px dashed var(--line-2);border-radius:var(--r-md);padding:12px 13px;margin-top:9px;color:var(--txt);font-size:14.5px;animation:pop .25s ease}
.hint .n{font-size:11.5px;font-weight:800;color:var(--accent);letter-spacing:.6px;text-transform:uppercase;display:block;margin-bottom:3px}
@keyframes pop{from{opacity:0;transform:translateY(6px)}to{opacity:1;transform:none}}
.idea{font-size:15px;line-height:1.55}
.cx{display:inline-block;font-family:var(--mono);font-size:13px;padding:5px 10px;border-radius:10px;background:rgba(62,200,255,.1);color:var(--cyan);margin-top:8px}

.btn{display:inline-flex;align-items:center;justify-content:center;gap:7px;padding:10px 15px;border-radius:12px;font-size:14px;font-weight:700;
  background:rgba(255,255,255,.07);border:1px solid var(--line-2)}
.btn.solid{background:linear-gradient(135deg,var(--accent),var(--accent-2));border-color:transparent;color:#fff}
.btn.sm{padding:6px 11px;font-size:13px;border-radius:10px}
.btn.block{width:100%}
.btn:disabled{opacity:.45}
.btns{display:flex;flex-wrap:wrap;gap:8px;margin-top:12px}

/* ---------- code ---------- */
.vtabs{display:flex;gap:6px;overflow-x:auto;scrollbar-width:none;margin:0 -14px 10px;padding:0 14px}
.vtabs::-webkit-scrollbar{display:none}
.vtab{flex:none;padding:7px 12px;border-radius:12px;font-size:13px;font-weight:700;color:var(--dim);background:var(--card);border:1px solid var(--line);display:flex;align-items:center;gap:6px}
.vtab.on{color:var(--txt);border-color:rgba(124,92,255,.6);background:rgba(124,92,255,.14)}
.vtab .dot{width:7px;height:7px;border-radius:99px;background:var(--faint)}
.dot.ok{background:var(--ok)} .dot.warn{background:var(--warn)} .dot.bug{background:var(--bad)} .dot.fix{background:var(--cyan)}
pre.code{margin:10px 0 0;background:var(--code-bg);border:1px solid var(--line);border-radius:var(--r-md);padding:12px 13px;overflow-x:auto;
  font:12.8px/1.55 var(--mono);color:#e6e6f0;tab-size:4}
.code-head{display:flex;align-items:center;justify-content:space-between;gap:8px;margin-top:4px}
pre.code code{background:none;padding:0;border-radius:0;font-size:inherit}
.file{font-family:var(--mono);font-size:12px;color:var(--faint);overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.t-key{color:#c792ea}.t-str{color:#c3e88d}.t-com{color:#6b7394;font-style:italic}.t-num{color:#f78c6c}
.t-fn{color:#82aaff}.t-def{color:#ffcb6b}.t-type{color:#ffcb6b}.t-ann{color:#89ddff}.t-bi{color:#89ddff}
.note{border-radius:var(--r-md);padding:11px 13px;font-size:14px;margin-top:10px;line-height:1.5}
.note.ok{background:rgba(47,216,160,.08);border:1px solid rgba(47,216,160,.25)}
.note.warn{background:rgba(255,181,71,.08);border:1px solid rgba(255,181,71,.28)}
.note.bug{background:rgba(255,95,109,.08);border:1px solid rgba(255,95,109,.3)}
.note.info{background:rgba(124,92,255,.08);border:1px solid rgba(124,92,255,.28)}
.note b{font-weight:750}
.proof{margin-top:10px;border-radius:var(--r-md);border:1px solid rgba(255,95,109,.3);overflow:hidden}
.proof .ph{font-size:12px;font-weight:800;letter-spacing:.6px;text-transform:uppercase;color:var(--bad);padding:8px 12px;background:rgba(255,95,109,.08)}
.proof .pr{padding:8px 12px;border-top:1px solid var(--line);font:12.5px/1.5 var(--mono);color:var(--dim);word-break:break-word}
.proof .pr .got{color:var(--bad)}
.results{margin-top:10px;border:1px solid var(--line);border-radius:var(--r-md);overflow:hidden}
.results .r{display:flex;gap:9px;padding:7px 11px;border-top:1px solid var(--line);font:12.5px/1.45 var(--mono);color:var(--dim);word-break:break-word}
.results .r:first-child{border-top:0}
.results .s{flex:none;font-weight:800;width:38px}
.results .PASS .s{color:var(--ok)} .results .FAIL .s,.results .ERR .s,.results .LOAD .s{color:var(--bad)}
.results .sum{padding:8px 11px;font-size:13px;font-weight:700;background:rgba(255,255,255,.03)}
.editor{width:100%;min-height:220px;margin-top:10px;background:var(--code-bg);border:1px solid var(--line-2);border-radius:var(--r-md);padding:12px;
  font:13px/1.5 var(--mono);color:#e6e6f0;resize:vertical;outline:none;tab-size:4;white-space:pre}
.status{font-size:13px;color:var(--dim);margin-top:8px}

/* ---------- train ---------- */
.big{font-size:34px;font-weight:850;letter-spacing:-1px}
.opt{display:block;width:100%;text-align:left;padding:13px 14px;border-radius:var(--r-md);background:var(--card);border:1px solid var(--line-2);font-size:14.5px;font-weight:650;margin-top:8px}
.opt.right{border-color:var(--ok);background:rgba(47,216,160,.1)}
.opt.wrong{border-color:var(--bad);background:rgba(255,95,109,.1)}
.coach-step{border-left:3px solid rgba(124,92,255,.5);padding:2px 0 2px 12px;margin:16px 0 0}
.coach-step h4{font-size:15px;font-weight:750}
.coach-step p{color:var(--faint);font-size:13px;margin:2px 0 7px}
.coach-step textarea{width:100%;min-height:62px;background:var(--card);border:1px solid var(--line-2);border-radius:12px;padding:10px 11px;font-size:14px;outline:none;resize:vertical}
.check{display:flex;gap:9px;align-items:flex-start;padding:7px 0;font-size:14px;color:var(--dim);border-top:1px solid var(--line)}
.check:first-child{border-top:0}
.check input{margin-top:3px;accent-color:var(--accent);width:17px;height:17px}
.stat{background:var(--card);border:1px solid var(--line);border-radius:var(--r-lg);padding:13px 14px}
.stat b{display:block;font-size:24px;font-weight:850;letter-spacing:-.5px}
.stat span{color:var(--faint);font-size:12.5px}
.topic-row{display:flex;align-items:center;gap:10px;padding:9px 0;border-top:1px solid var(--line);font-size:14px}
.topic-row:first-child{border-top:0}
.topic-row .ico{width:30px;height:30px;border-radius:10px;display:grid;place-items:center;background:rgba(124,92,255,.14);flex:none}
.empty{text-align:center;color:var(--faint);padding:30px 10px;font-size:14px}
.toast{position:fixed;left:50%;bottom:calc(var(--tabh) + var(--safe-b) + 14px);transform:translateX(-50%);z-index:60;
  background:#23233a;border:1px solid var(--line-2);padding:9px 15px;border-radius:99px;font-size:13.5px;font-weight:600;animation:pop .2s ease}
table.cx-table{width:100%;border-collapse:collapse;font-size:13.5px}
table.cx-table td{padding:8px 6px;border-top:1px solid var(--line);color:var(--dim);vertical-align:top}
table.cx-table td:first-child{font-family:var(--mono);color:var(--txt);white-space:nowrap}
.kbd{font-family:var(--mono);font-size:12px;color:var(--faint)}