:root{
  --bg:#f6f7f9; --card:#fff; --ink:#1a1d21; --muted:#6b7280; --line:#e3e6ea;
  --accent:#2563eb; --ok:#0f9d58; --warn:#d97706; --bad:#dc2626;
  --code-bg:#0f172a; --code-ink:#e2e8f0;
}
@media (prefers-color-scheme: dark){
  :root{ --bg:#14171c; --card:#1c2027; --ink:#e6e8eb; --muted:#9aa3af;
         --line:#2b313a; --code-bg:#0b1220; }
}
*{box-sizing:border-box}
body{margin:0;background:var(--bg);color:var(--ink);
  font:15px/1.6 -apple-system,BlinkMacSystemFont,"Pretendard","Apple SD Gothic Neo",
  "Malgun Gothic",system-ui,sans-serif}
a{color:var(--accent);text-decoration:none}
a:hover{text-decoration:underline}
.topbar{display:flex;justify-content:space-between;align-items:center;gap:1rem;
  padding:.75rem 1.25rem;background:var(--card);border-bottom:1px solid var(--line)}
.brand{font-weight:700;color:var(--ink)}
.topbar nav{display:flex;gap:1rem;align-items:center}
.who{color:var(--muted);font-size:.9em}
.wrap{max-width:1240px;margin:1.25rem auto;padding:0 1.25rem}
h1{font-size:1.5rem;margin:.2rem 0 1rem}
h2{font-size:1.15rem;margin:0 0 .75rem}
h3{font-size:1rem;margin:1.4rem 0 .5rem}
h4{font-size:.82rem;margin:0 0 .25rem;color:var(--muted);font-weight:600}
.card{background:var(--card);border:1px solid var(--line);border-radius:12px;
  padding:1.25rem;margin-bottom:1.25rem}
.narrow{max-width:420px;margin:3rem auto}
.muted{color:var(--muted)}
.small{font-size:.85em}
.tiny{font-size:.78em}
.mono{font-family:ui-monospace,SFMono-Regular,Menlo,Consolas,monospace}
.mt{margin-top:1rem}
.row{display:flex;gap:.75rem;align-items:center;flex-wrap:wrap}
.spread{justify-content:space-between}
.error{color:var(--bad);background:color-mix(in srgb,var(--bad) 10%,transparent);
  padding:.5rem .75rem;border-radius:8px}
.ok-msg{color:var(--ok);background:color-mix(in srgb,var(--ok) 12%,transparent);
  padding:.5rem .75rem;border-radius:8px}

label{display:block;margin:.75rem 0;font-size:.9rem;font-weight:600}
input,textarea,select{width:100%;margin-top:.3rem;padding:.55rem .7rem;font:inherit;
  color:var(--ink);background:var(--bg);border:1px solid var(--line);border-radius:8px}
textarea.plain{font-family:ui-monospace,Menlo,Consolas,monospace;font-size:.88em}
label.check{display:flex;align-items:center;gap:.4rem;font-weight:500}
label.check input{width:auto;margin:0}
.grid3{display:grid;grid-template-columns:repeat(auto-fit,minmax(180px,1fr));gap:.75rem}

button,.btn{font:inherit;padding:.5rem .9rem;border-radius:8px;cursor:pointer;
  border:1px solid var(--line);background:var(--card);color:var(--ink)}
button:hover,.btn:hover{border-color:var(--accent);text-decoration:none}
.primary{background:var(--accent);color:#fff;border-color:var(--accent);font-weight:600}
.danger{background:var(--bad);color:#fff;border-color:var(--bad)}

.split{display:grid;grid-template-columns:minmax(0,1fr) minmax(0,1fr);gap:1.25rem;align-items:start}
@media(max-width:960px){.split{grid-template-columns:1fr}}
.pane{max-height:calc(100vh - 120px);overflow:auto}

.prose pre,pre.code{background:var(--code-bg);color:var(--code-ink);padding:.8rem;
  border-radius:8px;overflow:auto;font-size:.86em}
.prose code{background:color-mix(in srgb,var(--muted) 18%,transparent);
  padding:.1em .35em;border-radius:4px;font-size:.9em}
.prose pre code{background:none;padding:0}
pre{margin:0;white-space:pre-wrap;word-break:break-word;font-family:ui-monospace,Menlo,Consolas,monospace}
.sample{display:grid;grid-template-columns:1fr 1fr;gap:.75rem;margin-bottom:.6rem}
.sample pre{background:var(--bg);border:1px solid var(--line);padding:.6rem;
  border-radius:8px;font-size:.86em;min-height:2.4em}

.plist{list-style:none;padding:0;margin:0}
.plist li{display:flex;align-items:center;gap:.6rem;padding:.55rem 0;
  border-bottom:1px solid var(--line)}
.plist li:last-child{border:0}
.badge{font-size:.75em;padding:.15em .55em;border-radius:99px;font-weight:600}
.badge.ok{background:color-mix(in srgb,var(--ok) 18%,transparent);color:var(--ok)}
.badge.try{background:color-mix(in srgb,var(--warn) 18%,transparent);color:var(--warn)}
.badge.none{background:color-mix(in srgb,var(--muted) 15%,transparent);color:var(--muted)}

table{border-collapse:collapse;width:100%}
.mini th,.mini td{text-align:left;padding:.4rem .6rem;border-bottom:1px solid var(--line);
  font-size:.88em;vertical-align:top}
.mini th{color:var(--muted);font-weight:600}
.scrollx{overflow-x:auto}
.grid th,.grid td{border:1px solid var(--line);padding:.35rem .5rem;
  font-size:.85em;text-align:center;white-space:nowrap}
.grid .sticky{position:sticky;left:0;background:var(--card);text-align:left;z-index:1}
.grid thead th{background:var(--bg);color:var(--muted)}
.cell.ok{background:color-mix(in srgb,var(--ok) 16%,transparent)}
.cell.try{background:color-mix(in srgb,var(--warn) 14%,transparent)}

.v{font-weight:700;font-size:.85em}
.v-AC{color:var(--ok)} .v-WA{color:var(--bad)} .v-TLE{color:var(--warn)}
.v-RE,.v-CE,.v-OLE,.v-NOTC{color:var(--warn)}

.tc{display:grid;grid-template-columns:1fr 1fr auto;gap:.75rem;align-items:end;
  padding:.6rem 0;border-bottom:1px dashed var(--line)}
@media(max-width:760px){.tc{grid-template-columns:1fr}}

.CodeMirror{height:360px;border:1px solid var(--line);border-radius:8px;font-size:13.5px}
#result{margin-top:1rem}
.verdict-head{padding:.7rem .9rem;border-radius:8px;font-weight:700;margin-bottom:.75rem}
.verdict-head.pass{background:color-mix(in srgb,var(--ok) 15%,transparent);color:var(--ok)}
.verdict-head.fail{background:color-mix(in srgb,var(--bad) 12%,transparent);color:var(--bad)}
.case{border:1px solid var(--line);border-radius:8px;padding:.6rem .8rem;margin-bottom:.5rem}
.case.bad{border-color:color-mix(in srgb,var(--bad) 45%,var(--line))}
.diff{display:grid;grid-template-columns:1fr 1fr;gap:.6rem;margin-top:.5rem}
@media(max-width:700px){.diff{grid-template-columns:1fr}.sample{grid-template-columns:1fr}}
.diff pre{background:var(--bg);border:1px solid var(--line);padding:.5rem;
  border-radius:6px;font-size:.84em}

.btn.alert{border-color:var(--bad);color:var(--bad);font-weight:600}
.alert-box{border-left:4px solid var(--warn);
  background:color-mix(in srgb,var(--warn) 10%,transparent)}
.note{background:color-mix(in srgb,var(--accent) 7%,transparent);
  border-left:4px solid var(--accent)}
.warn-row{background:color-mix(in srgb,var(--warn) 12%,transparent)}