/* /sql: SQL practice workspace */
:root{--bg:#030507;--pan:#0a1016;--pan2:#0d151d;--line:#1d2a35;--ink:#eef3f6;--mut:#8894a0;--acc:#2de2c5;--bad:#ff5a5f;--warn:#ffb547;--blue:#6ea8ff;--code:#060a0e;--mono:"IBM Plex Mono",ui-monospace,monospace;--navh:68px}
*{box-sizing:border-box}
[hidden]{display:none!important}
html{-webkit-text-size-adjust:100%}
body{margin:0;background:var(--bg);color:var(--ink);font:15px/1.6 Manrope,system-ui,sans-serif;-webkit-font-smoothing:antialiased}
a{color:inherit}button{font:inherit;cursor:pointer;color:inherit}
:focus-visible{outline:2px solid var(--acc);outline-offset:2px}
h1,h2{font-family:"Instrument Serif",Georgia,serif;font-weight:400;line-height:1.08;letter-spacing:-.01em;margin:0}
code,pre{font-family:var(--mono)}
.eyebrow{font-family:var(--mono);color:var(--acc);font-size:11.5px;letter-spacing:.2em;text-transform:uppercase;margin:0 0 10px}
.muted{color:var(--mut)}.sm{font-size:13px}
.skip{position:absolute;left:-9999px;top:0}.skip:focus{left:16px;top:calc(12px + env(safe-area-inset-top,0px));z-index:40;background:var(--acc);color:#04211d;padding:8px 12px;text-decoration:none}
.linkbtn{background:none;border:0;color:var(--mut);padding:0;font:12.5px var(--mono);text-decoration:underline;text-underline-offset:3px}
.linkbtn:hover{color:var(--ink)}
.ico.block{width:100%;justify-content:center}
.ico:hover{color:var(--ink);border-color:#2b3d4c}
.ico:disabled,.btn:disabled{opacity:.5;cursor:default;transform:none}
input,select,textarea{font:inherit;color:var(--ink);background:var(--pan);border:1px solid var(--line);border-radius:0}

/* ---------------------------------------------------------------- workspace */
.ws{display:grid;grid-template-columns:300px minmax(0,1fr);height:calc(100dvh - var(--navh) - env(safe-area-inset-top,0px))}
.ws-list{border-right:1px solid var(--line);overflow-y:auto;min-height:0;overscroll-behavior:contain}
.ws-work{display:grid;grid-template-columns:minmax(0,1fr) 340px;min-height:0;min-width:0}
.ws:not(.has-q) .ws-work{grid-template-columns:minmax(0,1fr)}
.ws-main{overflow-y:auto;min-width:0;padding:28px clamp(20px,3vw,44px) 72px;container-type:inline-size;overscroll-behavior:contain}
.ws-side{border-left:1px solid var(--line);overflow-y:auto;background:var(--pan);min-width:0;overscroll-behavior:contain}

/* ---------------------------------------------------------------- list */
.ws-intro{padding:24px 18px 6px}
.ws-intro h1{font-size:30px;max-width:13ch}
.ws-stats{display:flex;gap:6px 16px;flex-wrap:wrap;margin-top:14px;font:11.5px/1.5 var(--mono);color:var(--mut)}
.ws-stats b{color:var(--ink);font-weight:500}
.ws-search{display:flex;gap:8px;padding:12px 18px;position:sticky;top:0;background:var(--bg);z-index:2}
.ws-search input{flex:1;min-width:0;padding:9px 12px;font-size:14px;-webkit-appearance:none;appearance:none}
.ws-search input::placeholder{color:#5d6b77}
.ws-search .ico[aria-expanded="true"]{color:var(--acc);border-color:var(--acc)}
.filters{padding:2px 18px 14px;border-bottom:1px solid var(--line);display:grid;gap:12px}
.fgroup{display:grid;gap:6px}
.flabel{font:11px var(--mono);letter-spacing:.14em;text-transform:uppercase;color:var(--mut)}
.frow{display:flex;justify-content:space-between;align-items:center;gap:10px;flex-wrap:wrap}
.check{display:flex;gap:8px;align-items:center;font-size:13px;color:var(--mut);cursor:pointer}
.check input{accent-color:var(--acc);width:16px;height:16px;margin:0}
.filters select{padding:6px 8px;font-size:13px}
.filters .linkbtn{justify-self:start}
.chips{display:flex;flex-wrap:wrap;gap:6px}
#filter-tags{max-height:132px;overflow-y:auto}
.chip{background:transparent;border:1px solid var(--line);color:var(--mut);padding:4px 9px;font:12px/1.4 var(--mono)}
.chip span{opacity:.6}
.chip[aria-pressed="true"]{border-color:var(--acc);color:var(--acc)}
.list-meta{margin:0;padding:10px 18px 8px;font:11.5px var(--mono);color:var(--mut);border-bottom:1px solid var(--line)}
.qlist{list-style:none;margin:0;padding:0 0 28px}
.qrow{display:grid;grid-template-columns:22px minmax(0,1fr);column-gap:6px;padding:11px 18px 12px 14px;border-bottom:1px solid var(--line);text-decoration:none;color:var(--ink)}
.qrow:hover{background:var(--pan)}
.qrow[aria-current="page"]{background:var(--pan2);box-shadow:inset 2px 0 0 var(--acc)}
.qrow .n{font:11px/1.9 var(--mono);color:#5d6b77;text-align:right;padding-right:2px}
.qrow .t{font-weight:500;font-size:14.5px;line-height:1.38}
.qrow .m{grid-column:2;display:flex;gap:8px;align-items:center;flex-wrap:wrap;margin-top:5px;font:11px var(--mono);color:var(--mut)}
.dot{width:8px;height:8px;border-radius:50%;border:1px solid #4d5a66;flex:none;display:inline-block}
.dot.attempted{border-color:var(--warn);background:var(--warn)}
.dot.solved{border-color:var(--acc);background:var(--acc)}
.diff.easy{color:var(--acc)}.diff.medium{color:var(--warn)}.diff.hard{color:var(--bad)}
.star{color:var(--warn)}
.list-empty{padding:24px 18px;color:var(--mut);font-size:14px}

/* ---------------------------------------------------------------- empty state */
.empty{max-width:640px;margin:clamp(24px,8vh,90px) auto 0}
.empty h2{font-size:clamp(38px,4.6vw,56px);max-width:15ch}
.steps{margin:28px 0 20px;padding:0;list-style:none;counter-reset:s;display:grid;gap:14px}
.steps li{counter-increment:s;position:relative;padding-left:36px;color:#c9d3da}
.steps li::before{content:"0" counter(s);position:absolute;left:0;top:0;font:12px/2.1 var(--mono);color:var(--acc)}
.steps b{color:var(--ink);font-weight:600}
.empty code{font-size:.92em;color:var(--warn)}
.empty .muted{font-size:14px;margin:0 0 24px}

/* ---------------------------------------------------------------- question */
.q{max-width:1000px;margin:0 auto}
.back{display:none;margin-bottom:18px}
.q-head{display:flex;justify-content:space-between;gap:16px;align-items:flex-start}
.q-head h1{font-size:clamp(30px,3.4vw,44px)}
.q-meta{display:flex;gap:6px 12px;flex-wrap:wrap;align-items:center;margin-bottom:10px;font:11.5px var(--mono);color:var(--mut)}
.q-meta .st-solved{color:var(--acc)}.q-meta .st-attempted{color:var(--warn)}
.q-actions{display:flex;gap:6px;flex:none}
#btn-bookmark[aria-pressed="true"]{color:var(--warn);border-color:var(--warn)}
.q-body{color:#c9d3da;font-size:16px;line-height:1.72;white-space:pre-wrap;margin:16px 0 22px;max-width:76ch}
.panel{border:1px solid var(--line);background:var(--pan);margin-bottom:10px}
.panel summary{cursor:pointer;padding:11px 14px;font:11.5px var(--mono);letter-spacing:.12em;text-transform:uppercase;color:var(--mut);list-style:none;display:flex;gap:8px;align-items:center}
.panel summary::-webkit-details-marker{display:none}
.panel summary::before{content:"";width:6px;height:6px;border-right:1.5px solid currentColor;border-bottom:1.5px solid currentColor;transform:rotate(-45deg);transition:transform .2s;margin-right:2px}
.panel[open] summary::before{transform:rotate(45deg)}
.panel summary:hover{color:var(--ink)}
.panel>div,.panel>.hint{padding:0 14px 14px}
.hint{margin:0;color:#c9d3da;font-size:15px}
.tname{font:12px var(--mono);color:var(--acc);margin:4px 0 6px}
.tname:not(:first-child){margin-top:16px}

/* tables */
.grid-wrap{overflow:auto;border:1px solid var(--line);max-height:340px;background:var(--bg);-webkit-overflow-scrolling:touch}
table.grid{border-collapse:collapse;font:12.5px/1.45 var(--mono);min-width:100%}
.grid th{position:sticky;top:0;background:var(--pan2);text-align:left;font-weight:500;color:var(--mut);padding:7px 12px;border-bottom:1px solid var(--line);white-space:nowrap}
.grid td{padding:6px 12px;border-bottom:1px solid #111b23;white-space:nowrap}
.grid td.num{text-align:right}
.grid td.null{color:#5d6b77;font-style:italic}
.grid td.bad{background:#ff5a5f24;color:#ffc4c6}
.grid tr:last-child td{border-bottom:0}
.table-empty{font:12.5px var(--mono);color:var(--mut);padding:10px 0}

/* ---------------------------------------------------------------- editor */
.editor{border:1px solid var(--line);margin-top:22px;background:var(--pan)}
.ed-bar{display:flex;align-items:center;gap:10px;padding:8px;border-bottom:1px solid var(--line);flex-wrap:wrap}
.seg{display:inline-flex;border:1px solid var(--line)}
.seg button{background:transparent;border:0;color:var(--mut);padding:6px 12px;font:12px var(--mono);letter-spacing:.04em}
.seg button+button{border-left:1px solid var(--line)}
.seg button[aria-pressed="true"]{background:var(--acc);color:#04211d}
.seg button:not([aria-pressed="true"]):hover{color:var(--ink)}
.ed-status{font:11.5px var(--mono);color:var(--mut);flex:1;min-width:0}
.ed-actions{display:flex;gap:6px;align-items:center;flex-wrap:wrap}
.ed-actions .ico{padding:7px 10px;font-size:11px}
.btn.run{padding:8px 18px;font-size:14px;min-width:82px}
.ed-host .CodeMirror{height:auto;background:var(--code);color:var(--ink);font:14px/1.6 var(--mono)}
.ed-host .CodeMirror-scroll{min-height:200px;max-height:58vh}
.ed-host .CodeMirror-lines{padding:10px 0}
.ed-host .CodeMirror pre.CodeMirror-line,.ed-host .CodeMirror pre.CodeMirror-line-like{padding:0 12px}
.ed-host .CodeMirror-gutters{background:var(--code);border-right:1px solid var(--line)}
.ed-host .CodeMirror-linenumber{color:#3f4b56}
.ed-host .CodeMirror-cursor{border-left:2px solid var(--acc)}
.ed-host .CodeMirror-selected{background:#2de2c51f}
.ed-host .CodeMirror-focused .CodeMirror-selected,.ed-host .CodeMirror-line::selection,.ed-host .CodeMirror-line>span::selection{background:#2de2c533}
.ed-host .CodeMirror-placeholder{color:#4d5a66}
.ed-host .CodeMirror-matchingbracket{color:var(--acc)!important;text-decoration:underline}
.cm-s-default .cm-keyword{color:#2de2c5}
.cm-s-default .cm-string,.cm-s-default .cm-string-2{color:#ffb547}
.cm-s-default .cm-number,.cm-s-default .cm-atom{color:#6ea8ff}
.cm-s-default .cm-comment{color:#5d6b77;font-style:italic}
.cm-s-default .cm-builtin,.cm-s-default .cm-type{color:#9fd8ff}
.cm-s-default .cm-variable-2,.cm-s-default .cm-variable-3{color:#d9c2ff}
.cm-s-default .cm-operator,.cm-s-default .cm-bracket,.cm-s-default .cm-punctuation{color:#c9d3da}
.CodeMirror-hints{background:var(--pan2);border:1px solid var(--line);border-radius:0;box-shadow:0 8px 24px #0009;font:12.5px var(--mono);z-index:30}
.CodeMirror-hint{color:var(--ink);border-radius:0;padding:2px 8px}
li.CodeMirror-hint-active{background:var(--acc);color:#04211d}
.ed-host textarea.fallback{display:block;width:100%;min-height:220px;background:var(--code);border:0;padding:12px;font:14px/1.6 var(--mono);resize:vertical}
.ed-note{margin:0;padding:9px 12px;border-top:1px solid var(--line);font-size:13px;color:var(--mut)}
.ed-note code{color:var(--warn)}

/* ---------------------------------------------------------------- results */
.results{margin-top:18px;display:grid;gap:12px}
.results:empty{display:none}
.verdict{display:flex;gap:14px;align-items:flex-start;border:1px solid var(--line);border-left:3px solid var(--mut);background:var(--pan);padding:14px 16px}
.verdict.good{border-left-color:var(--acc)}.verdict.warn{border-left-color:var(--warn)}.verdict.bad{border-left-color:var(--bad)}
.vmark{font-size:22px;line-height:1.1;flex:none}
.verdict.good .vmark{color:var(--acc)}.verdict.warn .vmark{color:var(--warn)}.verdict.bad .vmark{color:var(--bad)}
.verdict h3{font-size:16px;font-weight:600;margin:0;line-height:1.45}
.verdict p{margin:4px 0 0;color:var(--mut);font-size:14px}
.engine-note{font:11.5px var(--mono);color:var(--mut);margin-top:6px}
.cols{display:grid;grid-template-columns:minmax(0,1fr) minmax(0,1fr);gap:12px}
@container (max-width:760px){.cols{grid-template-columns:minmax(0,1fr)}}
.card{border:1px solid var(--line);background:var(--pan);padding:12px;min-width:0}
.card h4{font:11px var(--mono);letter-spacing:.14em;text-transform:uppercase;color:var(--mut);margin:0 0 10px;font-weight:500}
.diff-list{list-style:none;margin:0;padding:0;font:12.5px/1.65 var(--mono);display:grid;gap:2px;overflow-wrap:anywhere}
.yours{color:#ff9a9d}.want{color:var(--acc)}
pre.err,pre.plan,pre.code{white-space:pre-wrap;overflow-wrap:anywhere;margin:0;padding:12px 14px;font:13px/1.55 var(--mono)}
pre.err{border:1px solid #ff5a5f55;background:#ff5a5f12;color:#ffc4c6}
pre.plan{border:1px solid var(--line);background:var(--code);color:#c9d3da;white-space:pre;overflow-x:auto}
pre.code{border:1px solid var(--line);background:var(--code);color:#c9d3da;white-space:pre;overflow-x:auto;font-size:12.5px}
.spinner{display:inline-block;width:14px;height:14px;border:2px solid #04211d55;border-top-color:#04211d;border-radius:50%;animation:spin .7s linear infinite;vertical-align:-2px}
@keyframes spin{to{transform:rotate(360deg)}}

/* ---------------------------------------------------------------- side panel */
.tabs{display:flex;border-bottom:1px solid var(--line);position:sticky;top:0;background:var(--pan);z-index:2}
.tab{flex:1;background:transparent;border:0;border-bottom:2px solid transparent;color:var(--mut);padding:13px 4px 11px;font:11px var(--mono);letter-spacing:.08em;text-transform:uppercase;white-space:nowrap}
.tab[aria-selected="true"]{color:var(--ink);border-bottom-color:var(--acc)}
.tab:hover{color:var(--ink)}
.badge{color:var(--acc)}
.tab-panel{padding:14px}
.tab-panel>p,.side-empty{color:var(--mut);font-size:14px;margin:12px 0 0}
.version{border:1px solid var(--line);margin-top:8px;background:var(--bg)}
.version.pinned{border-color:#2de2c566}
.version-head{display:flex;gap:8px;align-items:center;width:100%;padding:9px 10px;background:transparent;border:0;text-align:left;font-size:14px}
.version-head .vn{font:11px var(--mono);color:var(--mut)}
.version-head .vl{flex:1;min-width:0;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.ok{color:var(--acc)}.no{color:var(--bad)}
.version-body{padding:0 10px 10px;display:grid;gap:8px}
.version-meta{font:11px var(--mono);color:var(--mut)}
.version-actions{display:flex;flex-wrap:wrap;gap:6px}
.version-actions .ico{padding:6px 9px;font-size:10.5px}
.version-actions .danger:hover{color:var(--bad);border-color:var(--bad)}
.attempt{display:grid;grid-template-columns:18px minmax(0,1fr);column-gap:6px;width:100%;text-align:left;background:transparent;border:0;border-bottom:1px solid var(--line);padding:9px 2px}
.attempt:hover{background:var(--bg)}
.attempt code{font-size:12px;color:#c9d3da;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.attempt time{grid-column:2;font:11px var(--mono);color:var(--mut)}
.locked{text-align:center;padding:18px 6px;color:var(--mut);font-size:14px;display:grid;gap:12px;justify-items:center}
#official{display:grid;gap:10px}
#notes{width:100%;min-height:180px;padding:10px 12px;font-size:14px;line-height:1.6;resize:vertical}

/* ---------------------------------------------------------------- modal + toasts */
.modal{position:fixed;inset:0;z-index:50;background:#000a;display:grid;place-items:center;padding:16px}
.modal[hidden]{display:none}
.modal-box{width:min(760px,100%);max-height:calc(100dvh - 32px);overflow:auto;background:var(--pan);border:1px solid var(--line)}
.modal-head{display:flex;justify-content:space-between;align-items:center;gap:12px;padding:14px 16px;border-bottom:1px solid var(--line)}
.modal-head h2{font-size:26px}
.modal-body{padding:16px;display:grid;gap:12px}
.modal-body label{font:11px var(--mono);letter-spacing:.14em;text-transform:uppercase;color:var(--mut);display:grid;gap:6px}
.modal-body select{padding:8px;font:14px Manrope,system-ui,sans-serif;text-transform:none;letter-spacing:0}
.dl-add{color:var(--acc)}.dl-del{color:#ff9a9d}.dl-same{color:#5d6b77}
.toasts{position:fixed;right:16px;bottom:calc(16px + env(safe-area-inset-bottom,0px));z-index:60;display:grid;gap:8px;pointer-events:none}
.toast{background:var(--pan2);border:1px solid var(--line);border-left:3px solid var(--mut);padding:10px 14px;font-size:14px;box-shadow:0 8px 24px #0008;max-width:320px}
.toast.good{border-left-color:var(--acc)}.toast.bad{border-left-color:var(--bad)}

/* ---------------------------------------------------------------- tablet: list + one scrolling column */
@media(max-width:1179px){
  .ws{grid-template-columns:280px minmax(0,1fr)}
  .ws-work,.ws:not(.has-q) .ws-work{display:block;overflow-y:auto;overscroll-behavior:contain}
  .ws-main{overflow:visible;padding-bottom:28px}
  .ws-side{overflow:visible;border-left:0;border-top:1px solid var(--line)}
  .ws-side .tab-panel{max-width:1000px}
}

/* ---------------------------------------------------------------- phone: list and question are separate screens */
@media(max-width:860px){
  :root{--navh:64px}
  .ws{display:block;height:auto}
  .ws-list{overflow:visible;border-right:0}
  .ws-work,.ws:not(.has-q) .ws-work{overflow:visible}
  .ws[data-view="list"] .ws-work{display:none}
  .ws[data-view="question"] .ws-list{display:none}
  .ws-intro{padding:26px 16px 6px}
  .ws-intro h1{font-size:clamp(38px,11vw,52px)}
  .ws-search{top:calc(var(--navh) + env(safe-area-inset-top,0px));padding:12px 16px}
  .ws-search input,.filters select,#notes{font-size:16px}
  .filters{padding:2px 16px 14px}
  .list-meta{padding:10px 16px 8px}
  .qrow{padding:13px 16px 13px 10px}
  .ws-main{padding:18px 16px 28px}
  .back{display:inline-block}
  .q-head{flex-direction:column;gap:12px}
  .q-body{font-size:16px}
  .ed-host .CodeMirror,.ed-host textarea.fallback{font-size:16px}
  .ed-host .CodeMirror-scroll{min-height:180px;max-height:none}
  .btn.run{order:1;margin-left:auto}
  .ed-actions{order:2;flex-basis:100%}
  .ed-status{order:3;flex-basis:100%}
  .ed-status:empty{display:none}
  .grid-wrap{max-height:300px}
  .tabs{top:calc(var(--navh) + env(safe-area-inset-top,0px))}
  .tab{font-size:10.5px;letter-spacing:.04em}
  .tab-panel{padding:14px 16px 28px}
}
@media(prefers-reduced-motion:reduce){.spinner{animation-duration:2s}.btn{transition:none}}