/* 러너즈빌드업 · Data Learners 디자인 시스템 (다크 단일 테마).
   라임은 신호색: CTA, eyebrow, 핵심 숫자, 포커스 링에만 쓴다.
   카드는 오른쪽 위 대각 컷 + 상단 3px 액센트 바 (파이썬 트랙 = 바이올렛). */
:root {
  color-scheme: dark;
  --bg: #050607;
  --surface: #0b0d0e;
  --surface-2: #121516;
  --surface-3: #181c1d;
  --ink: #f5f7f2;
  --ink-2: #c9cfcb;
  --muted: #a1aaa5;
  --subtle: #879089;
  --line: rgba(255,255,255,.11);
  --line-strong: rgba(255,255,255,.22);
  --accent: #c8ff3d;
  --accent-ink: #0d1006;
  --accent-soft: rgba(200,255,61,.1);
  --track: #a896ff;
  --track-soft: rgba(168,150,255,.12);
  --cyan: #66dbff;
  --pass: #61db9c;
  --pass-soft: rgba(97,219,156,.13);
  --fail: #ff7a92;
  --fail-soft: rgba(255,122,146,.13);
  --warn: #ffcf4a;
  --warn-soft: rgba(255,207,74,.12);
  --orange: #ff9a51;
  --code-bg: #08090a;
  --shadow: 0 14px 34px rgba(0,0,0,.4);
  --shadow-cta: 0 10px 30px rgba(200,255,61,.22);
  --shadow-modal: 0 40px 120px rgba(0,0,0,.7);
  --font-body: "Pretendard Variable", Pretendard, "Apple SD Gothic Neo", "Malgun Gothic", system-ui, sans-serif;
  --font-en: "Space Grotesk", "Pretendard Variable", Pretendard, sans-serif;
  --font-mono: "JetBrains Mono", ui-monospace, "SFMono-Regular", Menlo, Consolas, monospace;
  --radius: 6px;
  --cut: 22px;
  --cut-shape: polygon(0 0, calc(100% - var(--cut)) 0, 100% var(--cut), 100% 100%, 0 100%);
}

* { box-sizing: border-box; }
html, body { height: 100%; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font: 15px/1.65 var(--font-body);
  -webkit-font-smoothing: antialiased;
  word-break: keep-all;
  overflow-wrap: anywhere;
  background-image:
    radial-gradient(900px 420px at 85% -10%, rgba(168,150,255,.08), transparent 60%),
    radial-gradient(700px 360px at 0% 0%, rgba(200,255,61,.05), transparent 60%);
  background-attachment: fixed;
}
button, input, textarea, select { font: inherit; color: inherit; }
code, pre, .mono { font-family: var(--font-mono); font-size: 0.92em; }
a { color: var(--accent); }
h1, h2, h3, h4 { line-height: 1.3; letter-spacing: -0.01em; text-wrap: balance; margin: 0; }
:focus-visible { outline: none; box-shadow: 0 0 0 2px var(--bg), 0 0 0 4px var(--accent); }
em, i { font-style: normal; }
[hidden] { display: none !important; }

/* ── 상단 바 ── */
.topbar {
  position: sticky; top: 0; z-index: 20;
  background: rgba(5,6,7,.82);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--line);
}
.topbar-inner {
  max-width: 1440px; margin: 0 auto;
  padding: 10px max(16px, env(safe-area-inset-right, 0px)) 10px max(16px, env(safe-area-inset-left, 0px));
  display: flex; align-items: center; gap: 12px; flex-wrap: wrap;
}
.brand { display: flex; align-items: center; gap: 10px; text-decoration: none; color: var(--ink); }
.brand-mark { width: 40px; height: auto; display: block; flex: none; }
.brand-block { display: grid; gap: 6px; }
.org-badge {
  display: inline-flex; align-items: center; gap: 7px; width: max-content;
  padding: 3px 10px 3px 4px; border: 1px solid var(--line-strong); border-radius: 999px; font-size: 13px; color: var(--ink-2);
}
.org-badge img { width: 18px; height: 18px; display: block; }
.org-badge b { color: var(--ink); font-weight: 700; }
.auth-mark { display: block; width: 56px; height: auto; margin-bottom: 14px; }
.brand-name { font: 700 16px/1.2 var(--font-en); letter-spacing: 0.01em; }
.brand-course { font: 600 12px/1.4 var(--font-en); color: var(--accent); letter-spacing: 0.16em; text-transform: uppercase; }
.topbar .spacer { flex: 1; }
.who { font-size: 14px; color: var(--muted); }
.who b { color: var(--ink); font-weight: 600; }
.mode-chip {
  font-size: 13px; padding: 2px 10px; border-radius: 999px;
  border: 1px solid rgba(255,207,74,.4); color: var(--warn); font-weight: 600;
}

/* ── 버튼 ── */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 6px;
  min-height: 42px; padding: 0 16px; border-radius: var(--radius);
  border: 1px solid var(--line-strong); background: transparent; color: var(--ink);
  cursor: pointer; font-weight: 600; font-size: 14px; white-space: nowrap; text-decoration: none;
  transition: transform .15s ease, box-shadow .15s ease, background .15s ease, border-color .15s ease;
}
.btn:hover { background: var(--surface-2); border-color: rgba(255,255,255,.34); }
.btn:disabled { opacity: 0.5; cursor: progress; transform: none !important; box-shadow: none !important; }
.btn.primary { background: var(--accent); border-color: var(--accent); color: var(--accent-ink); font-weight: 700; }
.btn.primary:hover { background: var(--accent); transform: translateY(-2px); box-shadow: var(--shadow-cta); }
.btn.ghost { border-color: transparent; background: transparent; color: var(--muted); }
.btn.ghost:hover { color: var(--ink); background: var(--surface-2); }
.btn.danger { color: var(--fail); border-color: rgba(255,122,146,.35); }
.btn.danger:hover { background: var(--fail-soft); border-color: var(--fail); }
.btn.small { min-height: 34px; padding: 0 12px; font-size: 13px; }
.btn.block { width: 100%; min-height: 52px; font-size: 15px; }

/* ── 공통 페이지 ── */
.page {
  max-width: 1040px; margin: 0 auto;
  padding-block: 28px 64px;
  padding-left: max(16px, env(safe-area-inset-left, 0px));
  padding-right: max(16px, env(safe-area-inset-right, 0px));
  display: grid; gap: 28px;
}
.page.wide { max-width: 1440px; }
.eyebrow {
  display: inline-flex; align-items: center; gap: 10px;
  font: 600 12px/1.4 var(--font-en); letter-spacing: 0.16em; color: var(--accent); text-transform: uppercase;
}
.eyebrow::before {
  content: ""; width: 22px; height: 8px; flex: none; transform: skewX(-18deg);
  background: repeating-linear-gradient(90deg, var(--accent) 0 3px, transparent 3px 6px);
}
.muted { color: var(--muted); }
.panel {
  position: relative;
  background: var(--surface); border: 1px solid var(--line);
  clip-path: var(--cut-shape);
}
.panel::before {
  content: ""; position: absolute; left: 0; top: 0; height: 3px; width: 100%; pointer-events: none;
  background: linear-gradient(90deg, var(--track), transparent 60%);
}
.panel.lime::before { background: linear-gradient(90deg, var(--accent), transparent 60%); }
/* 내부 스크롤·드롭다운이 잘리면 안 되는 패널은 컷 없이 */
.panel.flat { clip-path: none; }

/* ── 로그인 ── */
.login-wrap { min-height: 100%; display: grid; place-items: center; padding: 32px 16px; }
.login {
  width: min(440px, 100%); padding: 36px 30px 30px; display: grid; gap: 22px;
}
.login h1 { font-size: 28px; margin-top: 10px; }
.login-switch { display: grid; grid-template-columns: 1fr 1fr; gap: 4px; padding: 4px; border: 1px solid var(--line); border-radius: var(--radius); }
.login-switch a {
  text-align: center; padding: 8px 0; border-radius: 4px; text-decoration: none; color: var(--muted); font-weight: 600; font-size: 14px;
}
.login-switch a[aria-current="page"] { background: var(--ink); color: var(--bg); }
.login .lead { color: var(--muted); margin: 6px 0 0; font-size: 14px; }
.field { display: grid; gap: 6px; }
.field label { font-size: 13px; font-weight: 600; color: var(--ink-2); }
.field .hint-text { font-size: 13px; color: var(--subtle); margin: 0; }
.field input, .field textarea {
  width: 100%; padding: 12px 14px; border-radius: var(--radius);
  border: 1px solid var(--line-strong); background: var(--code-bg);
}
.field input::placeholder, .field textarea::placeholder { color: var(--subtle); }
.field input:focus, .field textarea:focus { outline: none; border-color: var(--accent); box-shadow: 0 0 0 3px var(--accent-soft); }
.pin-input { font-family: var(--font-mono); letter-spacing: 0.6em; font-size: 20px; text-align: center; }
.form-error { color: var(--fail); font-size: 14px; min-height: 1.4em; margin: 0; }
.login-foot a { color: var(--muted); }
.login-foot { color: var(--muted); display: flex; justify-content: space-between; align-items: center; font-size: 13px; gap: 8px; flex-wrap: wrap; }
.demo-note {
  background: var(--warn-soft); color: var(--ink-2); border: 1px solid rgba(255,207,74,.25); border-radius: var(--radius); padding: 10px 12px; font-size: 13px;
}
.demo-note b { color: var(--warn); }

/* ── 홈 ── */
.hero { display: flex; justify-content: space-between; align-items: end; gap: 20px; flex-wrap: wrap; }
.hero h1 { font-size: 34px; margin-top: 10px; }
.hero p { margin: 6px 0 0; color: var(--muted); }
.meter { min-width: 240px; display: grid; gap: 6px; }
.meter-label { display: flex; justify-content: space-between; font-size: 13px; color: var(--muted); }
.meter-label b { color: var(--accent); font-family: var(--font-en); font-size: 15px; font-variant-numeric: tabular-nums; }
.meter-bar { height: 6px; border-radius: 999px; background: var(--surface-3); overflow: hidden; }
.meter-bar span { display: block; height: 100%; background: var(--accent); border-radius: 999px; box-shadow: 0 0 12px rgba(200,255,61,.5); }

.unit { display: grid; gap: 10px; }
.unit-head { display: flex; align-items: baseline; gap: 12px; flex-wrap: wrap; }
.unit-num { font: 600 12px/1 var(--font-en); letter-spacing: 0.16em; color: var(--track); text-transform: uppercase; }
.unit-head h2 { font-size: 20px; }
.unit-head .muted { font-size: 13px; }
.unit-head .unit-count { margin-left: auto; font-size: 13px; color: var(--muted); font-variant-numeric: tabular-nums; }
.plist { list-style: none; margin: 0; padding: 0; }
.plist li + li { border-top: 1px solid var(--line); }
.prow {
  display: grid; grid-template-columns: 52px 1fr auto auto; align-items: center; gap: 14px;
  padding: 12px 16px; text-decoration: none; color: inherit;
}
.prow { transition: background .15s ease; }
.prow:hover { background: var(--surface-2); }
.prow:hover .ptitle { color: var(--accent); }
.prow .pid { font-family: var(--font-mono); font-size: 13px; color: var(--muted); }
.prow .ptitle { font-weight: 500; min-width: 0; }
.prow .porigin { display: block; font-size: 13px; color: var(--muted); font-weight: 400; }
.tags { display: flex; gap: 6px; align-items: center; }
.tag {
  font-size: 13px; padding: 1px 9px; border-radius: 999px; border: 1px solid var(--line-strong); color: var(--muted);
  white-space: nowrap;
}
.level { display: inline-flex; gap: 3px; }
.level i { width: 6px; height: 6px; border-radius: 50%; background: var(--line-strong); }
.level i.on { background: var(--track); }
.status {
  font-size: 13px; font-weight: 600; padding: 2px 10px; border-radius: 999px; border: 1px solid transparent; white-space: nowrap;
  min-width: 64px; text-align: center;
}
.status.solved { background: var(--pass-soft); color: var(--pass); border-color: rgba(97,219,156,.3); }
.status.tried { background: var(--fail-soft); color: var(--fail); border-color: rgba(255,122,146,.3); }
.status.none { color: var(--subtle); border-color: var(--line); }

/* ── 문제 화면 ── */
.solve {
  max-width: 1440px; margin: 0 auto;
  padding-block: 16px 40px;
  padding-left: max(16px, env(safe-area-inset-left, 0px));
  padding-right: max(16px, env(safe-area-inset-right, 0px));
  display: grid; gap: 14px;
}
.crumb { display: flex; align-items: center; gap: 10px; flex-wrap: wrap; font-size: 14px; }
.crumb a { text-decoration: none; }
.crumb .sep { color: var(--muted); }
.crumb .nav { margin-left: auto; display: flex; gap: 6px; }
.solve-grid { display: grid; grid-template-columns: minmax(0, 5fr) minmax(0, 7fr); gap: 14px; align-items: start; }
@media (max-width: 920px) { .solve-grid { grid-template-columns: minmax(0, 1fr); } }

.read.panel { clip-path: none; }
.read { min-width: 0; display: flex; flex-direction: column; max-height: calc(100vh - 120px); position: sticky; top: 70px; }
@media (max-width: 920px) { .read { position: static; max-height: none; } }
.tabs { display: flex; gap: 2px; padding: 6px 8px 0; border-bottom: 1px solid var(--line); overflow-x: auto; overflow-y: hidden; scrollbar-width: none; }
.tab {
  border: 0; background: none; padding: 8px 12px; cursor: pointer; color: var(--muted);
  border-bottom: 2px solid transparent; margin-bottom: -1px; font-weight: 500; white-space: nowrap;
}
.tab:hover { color: var(--ink); }
.tab[aria-selected="true"] { color: var(--ink); border-bottom-color: var(--accent); font-weight: 600; }
.read-body { padding: 18px 20px 24px; overflow: auto; display: grid; gap: 18px; align-content: start; }
.read-body h1 { font-size: 22px; }
.read-body h4 { color: var(--ink-2); }
.read-body h4 { font-size: 15px; margin-top: 6px; }
.read-body p { margin: 0; }
.read-body pre {
  margin: 0; padding: 10px 12px; background: var(--code-bg); border: 1px solid var(--line);
  border-radius: var(--radius); overflow-x: auto; white-space: pre; line-height: 1.5;
}
.read-body :not(pre) > code { background: var(--surface-3); color: var(--cyan); padding: 1px 5px; border-radius: 4px; }
.read-body ul, .read-body ol { margin: 0; padding-left: 20px; display: grid; gap: 4px; }
.read-body .qc {
  border-left: 3px solid var(--track); background: var(--track-soft); padding: 8px 12px; border-radius: 0 6px 6px 0; font-size: 14px; color: var(--ink-2);
}
.note { display: grid; gap: 10px; }
.meta-line { display: flex; gap: 8px; flex-wrap: wrap; align-items: center; }
.ex-table { width: 100%; border-collapse: collapse; font-size: 14px; }
.ex-table th, .ex-table td { border: 1px solid var(--line); padding: 6px 10px; text-align: left; vertical-align: top; }
.ex-table th { background: var(--surface-2); font-weight: 600; font-size: 13px; color: var(--ink-2); }
.ex-table td pre { border: 0; padding: 0; background: none; }
.table-scroll { overflow-x: auto; }
details.hint { border: 1px solid var(--line); border-radius: var(--radius); padding: 8px 12px; }
details.hint summary { cursor: pointer; font-weight: 500; color: var(--muted); }
details.hint[open] summary { color: var(--ink); margin-bottom: 6px; }
.locked-answer { font-size: 14px; color: var(--muted); border: 1px dashed var(--line-strong); border-radius: var(--radius); padding: 10px 12px; }

.write { min-width: 0; display: grid; gap: 10px; }
.editor-wrap { overflow: hidden; clip-path: none; }
.editor-head {
  display: flex; align-items: center; gap: 8px; padding: 6px 8px 6px 14px; border-bottom: 1px solid var(--line); font-size: 13px; color: var(--muted);
}
.editor-head .spacer { flex: 1; }
.CodeMirror {
  height: 380px; font-family: var(--font-mono); font-size: 14px; line-height: 1.55;
  background: var(--code-bg); color: var(--ink);
}
@media (max-width: 920px) { .CodeMirror { height: 300px; } }
.CodeMirror-gutters { background: var(--code-bg); border-right: 1px solid var(--line); }
.CodeMirror-linenumber { color: var(--muted); }
.CodeMirror-cursor { border-left-color: var(--ink); }
.CodeMirror-selected, .CodeMirror-focused .CodeMirror-selected { background: rgba(168,150,255,.22) !important; }
.CodeMirror-activeline-background { background: rgba(255,255,255,.03); }
.cm-s-default .cm-keyword { color: var(--track); }
.cm-s-default .cm-def { color: var(--cyan); }
.cm-s-default .cm-string { color: var(--pass); }
.cm-s-default .cm-number { color: var(--warn); }
.cm-s-default .cm-comment { color: var(--subtle); }
.cm-s-default .cm-builtin { color: var(--orange); }
.cm-s-default .cm-atom { color: var(--warn); }
.cm-s-default .cm-variable-2, .cm-s-default .cm-variable, .cm-s-default .cm-property { color: var(--ink); }
.cm-s-default .cm-operator { color: var(--ink-2); }
.CodeMirror-matchingbracket { color: var(--accent) !important; font-weight: 700; }

.actions { display: flex; gap: 8px; align-items: stretch; flex-wrap: wrap; }
.stdin { flex: 1 1 220px; display: grid; gap: 4px; }
.stdin label { font-size: 13px; color: var(--muted); font-weight: 600; }
.stdin textarea {
  width: 100%; min-height: 42px; height: 42px; resize: vertical; padding: 10px 10px; border-radius: var(--radius);
  border: 1px dashed var(--line-strong); background: var(--code-bg); font-family: var(--font-mono); font-size: 13px;
}
.actions .btns { display: flex; gap: 8px; align-items: end; margin-left: auto; }
.actions .btn { min-height: 42px; min-width: 92px; }
.engine { font-size: 13px; color: var(--muted); display: flex; align-items: center; gap: 6px; }
.engine .dot { width: 7px; height: 7px; border-radius: 50%; background: var(--warn); }
.engine.ready .dot { background: var(--pass); box-shadow: 0 0 8px var(--pass); }
.engine.error .dot { background: var(--fail); }

.result { min-height: 120px; }
.result-head { display: flex; align-items: center; gap: 10px; padding: 10px 14px; border-bottom: 1px solid var(--line); flex-wrap: wrap; }
.result-head h3 { font-size: 15px; }
.result-body { padding: 12px 14px 16px; display: grid; gap: 10px; }
.console {
  margin: 0; padding: 10px 12px; background: var(--code-bg); border: 1px solid var(--line); border-radius: var(--radius);
  font-family: var(--font-mono); font-size: 13px; white-space: pre-wrap; word-break: break-word; max-height: 260px; overflow: auto;
}
.console.empty { color: var(--muted); }
.err-box { border-left: 3px solid var(--fail); background: var(--fail-soft); border-radius: 0 6px 6px 0; padding: 10px 12px; display: grid; gap: 4px; font-size: 14px; }
.err-box .err-type { font-family: var(--font-mono); font-weight: 600; color: var(--fail); }
.verdict { font-weight: 700; font-size: 13px; padding: 2px 12px; border-radius: 999px; }
.verdict.pass { background: var(--accent); color: var(--accent-ink); }
.verdict.fail { background: var(--fail-soft); color: var(--fail); }
.score { font-family: var(--font-mono); font-size: 13px; color: var(--muted); }
.cases { display: grid; gap: 8px; }
.case { border: 1px solid var(--line); border-radius: var(--radius); overflow: hidden; }
.case-head { display: flex; align-items: center; gap: 8px; padding: 7px 12px; background: var(--surface-2); font-size: 13px; }
.case-head .mark { font-weight: 700; width: 18px; text-align: center; }
.case.ok .mark { color: var(--pass); }
.case.no .mark { color: var(--fail); }
.case-body { padding: 8px 12px 10px; display: grid; gap: 6px; font-size: 13px; }
.io-grid { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 8px; }
@media (max-width: 560px) { .io-grid { grid-template-columns: minmax(0, 1fr); } }
.io-grid > div { min-width: 0; }
.io-grid .k { font-size: 13px; font-weight: 600; color: var(--muted); }
.io-grid pre { margin: 2px 0 0; padding: 6px 8px; background: var(--code-bg); border-radius: 6px; font-size: 13px; white-space: pre-wrap; word-break: break-word; }
.case-note { color: var(--fail); }

/* ── 축하 모달 ── */
.overlay {
  position: fixed; inset: 0; z-index: 50; background: rgba(5,6,7,.72); backdrop-filter: blur(4px);
  display: grid; place-items: center; padding: 16px;
}
.celebrate {
  width: min(420px, 100%); background: var(--surface); border: 1px solid var(--line-strong); padding: 34px 28px 26px;
  text-align: center; display: grid; gap: 10px; box-shadow: var(--shadow-modal);
  clip-path: var(--cut-shape); position: relative;
  animation: pop 320ms cubic-bezier(.2,1.4,.4,1);
}
@keyframes pop { from { transform: scale(0.85); opacity: 0; } to { transform: scale(1); opacity: 1; } }
.celebrate .medal {
  width: 76px; height: 76px; margin: 0 auto 4px; border-radius: 50%; display: grid; place-items: center;
  font: 700 28px/1 var(--font-en);
  background: var(--accent-soft); color: var(--accent); border: 2px solid var(--accent);
  box-shadow: 0 0 32px rgba(200,255,61,.25);
}
.celebrate .medal.r1 { background: rgba(255,207,74,.14); color: var(--warn); border-color: var(--warn); box-shadow: 0 0 36px rgba(255,207,74,.35); }
.celebrate .medal.r2 { background: rgba(214,222,230,.1); color: #d6dee6; border-color: #b8c3cc; box-shadow: 0 0 30px rgba(214,222,230,.2); }
.celebrate .medal.r3 { background: rgba(255,154,81,.12); color: var(--orange); border-color: var(--orange); box-shadow: 0 0 30px rgba(255,154,81,.3); }
.celebrate h2 { font-size: 26px; }
.celebrate .rank-line { font-size: 17px; }
.celebrate .rank-line b { color: var(--accent); font-family: var(--font-en); font-size: 20px; font-variant-numeric: tabular-nums; }
.celebrate p { margin: 0; color: var(--muted); font-size: 14px; }
.celebrate .btns { display: flex; gap: 8px; justify-content: center; margin-top: 10px; flex-wrap: wrap; }

/* ── 어드민 ── */
.admin-tabs { display: flex; gap: 4px; border-bottom: 1px solid var(--line); overflow-x: auto; overflow-y: hidden; scrollbar-width: none; }
.admin-tabs::-webkit-scrollbar, .tabs::-webkit-scrollbar { display: none; }
.admin-tabs a { padding: 10px 14px; text-decoration: none; color: var(--muted); border-bottom: 2px solid transparent; margin-bottom: -1px; white-space: nowrap; font-weight: 500; }
.admin-tabs a[aria-current="page"] { color: var(--ink); border-bottom-color: var(--accent); font-weight: 600; }
.kpis { display: grid; grid-template-columns: repeat(auto-fit, minmax(160px, 1fr)); gap: 12px; }
.kpi { padding: 18px 18px 16px; display: grid; gap: 4px; }
.kpi .k { font-size: 13px; color: var(--muted); font-weight: 600; }
.kpi .v { font: 700 30px/1.1 var(--font-en); color: var(--ink); font-variant-numeric: tabular-nums; }
.toolbar { display: flex; gap: 8px; align-items: center; flex-wrap: wrap; }
.toolbar .spacer { flex: 1; }
.legend { display: flex; gap: 12px; font-size: 13px; color: var(--muted); flex-wrap: wrap; }
.legend span { display: inline-flex; align-items: center; gap: 5px; }
.legend i { width: 12px; height: 12px; border-radius: 3px; display: inline-block; }
.matrix-scroll { overflow: auto; max-height: 70vh; clip-path: none; }
.matrix { border-collapse: separate; border-spacing: 0; font-size: 13px; font-variant-numeric: tabular-nums; }
.matrix th, .matrix td { border-bottom: 1px solid var(--line); border-right: 1px solid var(--line); padding: 0; text-align: center; }
.matrix thead th { position: sticky; top: 0; background: var(--surface-2); z-index: 2; padding: 8px 6px; font-family: var(--font-en); font-weight: 600; font-size: 13px; color: var(--ink-2); }
.matrix thead th.unit-sep, .matrix td.unit-sep { border-left: 2px solid var(--line-strong); }
.matrix .sname { position: sticky; left: 0; background: var(--surface); z-index: 1; text-align: left; padding: 8px 12px; white-space: nowrap; font-weight: 500; }
.matrix thead .sname { z-index: 3; background: var(--surface-2); font-family: var(--font-body); }
.matrix .ssum { padding: 8px 10px; font-weight: 600; white-space: nowrap; }
.cell {
  width: 44px; height: 36px; border: 0; cursor: pointer; font: inherit; font-weight: 600; display: block;
  background: transparent; color: var(--muted);
}
.cell.solved { background: var(--pass-soft); color: var(--pass); }
.cell.tried { background: var(--fail-soft); color: var(--fail); }
.cell:hover { outline: 2px solid var(--accent); outline-offset: -2px; }
.cell:disabled { cursor: default; outline: none; }
.drawer {
  position: fixed; top: 0; right: 0; bottom: 0; z-index: 40; width: min(620px, 100%);
  background: var(--surface); border-left: 1px solid var(--line-strong); box-shadow: var(--shadow-modal);
  display: flex; flex-direction: column;
  padding-bottom: env(safe-area-inset-bottom, 0px); padding-right: env(safe-area-inset-right, 0px);
}
.drawer-head { display: flex; align-items: center; gap: 10px; padding: calc(14px + env(safe-area-inset-top, 0px)) 16px 14px; border-bottom: 1px solid var(--line); }
.drawer-head h3 { font-size: 16px; }
.drawer-head .spacer { flex: 1; }
.drawer-body { overflow: auto; padding: 14px 16px 24px; display: grid; gap: 12px; align-content: start; }
.sub { border: 1px solid var(--line); border-radius: var(--radius); overflow: hidden; }
.sub-head { display: flex; gap: 8px; align-items: center; padding: 8px 12px; background: var(--surface-2); font-size: 13px; }
.sub-head .when { margin-left: auto; color: var(--muted); font-variant-numeric: tabular-nums; }
.sub pre { margin: 0; padding: 10px 12px; font-size: 13px; overflow-x: auto; background: var(--code-bg); max-height: 320px; }
.sub .fails { padding: 8px 12px; font-size: 13px; display: grid; gap: 4px; border-top: 1px solid var(--line); }
.sub .fails div { color: var(--fail); word-break: break-word; }

.roster-grid { display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1.3fr); gap: 16px; align-items: start; }
@media (max-width: 860px) { .roster-grid { grid-template-columns: minmax(0, 1fr); } }
.card-pad { padding: 18px; display: grid; gap: 12px; }
.card-pad h3 { font-size: 16px; }
.card-pad textarea { min-height: 180px; font-family: var(--font-body); }
.pin-list { width: 100%; border-collapse: collapse; font-size: 14px; }
.pin-list th, .pin-list td { padding: 8px 10px; border-bottom: 1px solid var(--line); text-align: left; }
.pin-list th { font-size: 13px; color: var(--muted); font-weight: 600; }
.pin-list .pin { font-family: var(--font-mono); font-weight: 700; color: var(--accent); letter-spacing: 0.15em; font-size: 15px; }
.pin-list td.act { text-align: right; white-space: nowrap; }
.new-pins { background: var(--accent-soft); border: 1px solid rgba(200,255,61,.25); border-radius: var(--radius); padding: 12px; display: grid; gap: 8px; }
.lock-chip { font-size: 13px; padding: 0 8px; border-radius: 999px; background: var(--fail-soft); color: var(--fail); margin-left: 6px; }

.stats-table { width: 100%; border-collapse: collapse; font-size: 14px; }
.stats-table th, .stats-table td { padding: 10px 12px; border-bottom: 1px solid var(--line); text-align: left; }
.stats-table th { font-size: 13px; color: var(--muted); font-weight: 600; }
.stats-table td.num { font-variant-numeric: tabular-nums; text-align: right; white-space: nowrap; }
.rate { display: flex; align-items: center; gap: 8px; min-width: 160px; }
.rate .bar { flex: 1; height: 6px; background: var(--surface-3); border-radius: 99px; overflow: hidden; }
.rate .bar span { display: block; height: 100%; border-radius: 99px; background: var(--pass); }
.rate .bar span.low { background: var(--fail); }
.rate .bar span.mid { background: var(--warn); }
.rate b { width: 40px; text-align: right; font-variant-numeric: tabular-nums; }

.empty-state { padding: 28px; text-align: center; color: var(--muted); display: grid; gap: 10px; justify-items: center; }

.toast {
  position: fixed; left: 50%; bottom: calc(24px + env(safe-area-inset-bottom, 0px)); transform: translateX(-50%); z-index: 60;
  background: var(--surface-3); color: var(--ink); border: 1px solid var(--line-strong); border-left: 3px solid var(--accent);
  padding: 10px 16px; border-radius: var(--radius); font-size: 14px; box-shadow: var(--shadow-float, 0 14px 34px rgba(0,0,0,.4));
  max-width: calc(100% - 32px);
}

@media (prefers-reduced-motion: reduce) {
  .celebrate { animation: none; }
  .btn, .prow { transition: none; }
  .btn.primary:hover { transform: none; }
}
@media (max-width: 560px) {
  .prow { grid-template-columns: 40px 1fr auto; }
  .prow .tags { display: none; }
  .hero h1 { font-size: 23px; }
}

/* ── 사용 방법 ── */
kbd {
  font: 600 12px/1 var(--font-en); padding: 3px 7px; border-radius: 4px;
  border: 1px solid var(--line-strong); border-bottom-width: 2px; background: var(--surface-3); color: var(--ink);
}
.quick-guide { padding: 22px 22px 20px; display: grid; gap: 16px; }
.qg-head { display: flex; justify-content: space-between; align-items: end; gap: 12px; flex-wrap: wrap; }
.qg-head h2 { font-size: 20px; margin-top: 8px; }
.qg-steps { list-style: none; margin: 0; padding: 0; display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 12px; counter-reset: qg; }
@media (max-width: 860px) { .qg-steps { grid-template-columns: repeat(2, minmax(0, 1fr)); } }
@media (max-width: 520px) { .qg-steps { grid-template-columns: minmax(0, 1fr); } }
.qg-steps li {
  counter-increment: qg; display: grid; gap: 4px; align-content: start;
  padding: 14px; background: var(--surface-2); border: 1px solid var(--line); border-radius: var(--radius);
}
.qg-steps li::before { content: "0" counter(qg); font: 700 13px/1 var(--font-en); color: var(--accent); letter-spacing: 0.08em; }
.qg-steps b { font-size: 15px; }
.qg-steps span { font-size: 14px; color: var(--muted); }
.guide-toc { display: flex; flex-wrap: wrap; gap: 8px; padding: 10px; background: transparent; border: 0; }
.guide-toc::before { display: none; }
.guide-toc a {
  padding: 6px 14px; border-radius: 999px; border: 1px solid var(--line-strong); color: var(--ink-2);
  text-decoration: none; font-size: 14px; font-weight: 600;
}
.guide-toc a:hover { border-color: var(--accent); color: var(--accent); }
.guide-sec { padding: 26px 24px 24px; display: grid; gap: 14px; scroll-margin-top: 80px; }
.guide-sec h2 { font-size: 22px; }
.guide-sec h2 code, .guide-sec h2 b { color: var(--accent); font-weight: 700; }
.guide-sec > p { margin: 0; color: var(--ink-2); }
.guide-sec h3 { font-size: 15px; margin-bottom: 8px; color: var(--ink); }
.guide-sec ul { margin: 0; padding-left: 18px; display: grid; gap: 6px; color: var(--ink-2); font-size: 14px; }
.guide-sec :not(pre) > code { background: var(--surface-3); color: var(--cyan); padding: 1px 5px; border-radius: 4px; }
.guide-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 18px 24px; }
@media (max-width: 760px) { .guide-grid { grid-template-columns: minmax(0, 1fr); } }
.guide-code {
  margin: 0 0 10px; padding: 12px 14px; background: var(--code-bg); border: 1px solid var(--line);
  border-left: 3px solid var(--track); border-radius: var(--radius); overflow-x: auto; font-size: 13px; line-height: 1.6; color: var(--ink);
}
.guide-table td, .guide-table th { font-size: 14px; }

/* ── 코드 편집기 글자 크기 (--fs) ── */
:root { --fs: 1; }
.CodeMirror { font-size: calc(14px * var(--fs)); }
.font-ctl { display: inline-flex; align-items: center; gap: 2px; border: 1px solid var(--line); border-radius: var(--radius); padding: 2px; }
.font-ctl .btn { min-height: 28px; padding: 0 8px; font-size: 13px; }
.font-ctl span { font: 600 12px/1 var(--font-en); color: var(--muted); min-width: 38px; text-align: center; font-variant-numeric: tabular-nums; }
.editor-head .font-ctl { margin-right: 4px; }

/* ── 이 문제에서 쓰는 함수 ── */
.uses { border: 1px solid var(--line); border-left: 3px solid var(--accent); border-radius: var(--radius); padding: 12px 14px; display: grid; gap: 8px; background: var(--accent-soft); }
.uses h4 { margin: 0 !important; font-size: 14px; color: var(--accent) !important; }
.uses dl { margin: 0; display: grid; gap: 6px; }
.uses dl > div { display: grid; grid-template-columns: minmax(120px, max-content) 1fr; gap: 4px 12px; align-items: baseline; }
@media (max-width: 520px) { .uses dl > div { grid-template-columns: minmax(0, 1fr); } }
.uses dt code { background: var(--code-bg) !important; color: var(--ink) !important; border: 1px solid var(--line); }
.uses dd { margin: 0; font-size: 14px; color: var(--ink-2); }

/* ── 오늘의 과제 ── */
.today { display: grid; gap: 14px; }
.today-head { display: flex; justify-content: space-between; align-items: end; gap: 12px; flex-wrap: wrap; }
.today-head h2 { font-size: 24px; margin-top: 8px; }
.today-head p { margin: 4px 0 0; font-size: 14px; }
.today-count { font: 600 15px/1 var(--font-en); color: var(--muted); }
.today-count b { color: var(--accent); font-size: 28px; }
.today-list { list-style: none; margin: 0; padding: 0; display: grid; grid-template-columns: repeat(5, minmax(0, 1fr)); gap: 12px; }
@media (max-width: 1000px) { .today-list { grid-template-columns: repeat(3, minmax(0, 1fr)); } }
@media (max-width: 640px) { .today-list { grid-template-columns: minmax(0, 1fr); } }
.today-card {
  height: 100%; display: grid; gap: 6px; align-content: start; padding: 18px 16px 16px;
  text-decoration: none; color: inherit; transition: transform .15s ease, border-color .15s ease;
}
.today-card::before { background: linear-gradient(90deg, var(--accent), transparent 60%); }
.today-card:hover { transform: translateY(-2px); border-color: var(--line-strong); }
.today-card:hover .today-title { color: var(--accent); }
.today-card.done { opacity: .72; }
.today-card.done::before { background: linear-gradient(90deg, var(--pass), transparent 60%); }
.today-no { font: 700 26px/1 var(--font-en); color: var(--accent); }
.today-card .pid { font-family: var(--font-mono); font-size: 13px; color: var(--muted); }
.today-title { font-weight: 600; font-size: 15px; line-height: 1.45; min-height: 2.9em; }
.today-card .status { justify-self: start; margin-top: 4px; }
@media (prefers-reduced-motion: reduce) { .today-card { transition: none; } .today-card:hover { transform: none; } }

/* 어드민 · 오늘의 과제 선택 */
.today-pick { display: grid; gap: 10px; max-height: 360px; overflow: auto; padding-right: 4px; }
.today-pick fieldset { border: 1px solid var(--line); border-radius: var(--radius); padding: 8px 12px 10px; margin: 0; display: grid; gap: 4px; }
.today-pick legend { font: 600 12px/1 var(--font-en); letter-spacing: .1em; color: var(--track); padding: 0 4px; text-transform: uppercase; }
.today-pick label { display: flex; gap: 8px; align-items: center; font-size: 14px; cursor: pointer; }
.today-pick input { accent-color: #c8ff3d; width: 16px; height: 16px; }

/* ── 기본 / 도전 문제 구분 ── */
.plist-sep {
  padding: 10px 16px 6px; font-size: 13px; font-weight: 700; color: var(--muted); letter-spacing: .02em;
  background: var(--surface-2);
}
.plist .plist-sep + li { border-top: 1px solid var(--line); }
.plist-sep.challenge { color: var(--orange); }
.challenge-tag { border-color: rgba(255,154,81,.5) !important; color: var(--orange) !important; font-weight: 700; }
.prow.challenge .pid { color: var(--orange); }
.brand-course.org { display: inline-flex; align-items: center; gap: 6px; text-transform: none; letter-spacing: .06em; }
.brand-course.org img { width: 14px; height: 14px; display: block; }

/* ── 어드민 그룹 선택 ── */
.admin-bar { display: flex; align-items: end; gap: 12px; border-bottom: 1px solid var(--line); flex-wrap: wrap; }
.admin-bar .admin-tabs { border-bottom: 0; flex: 1; }
.group-select { display: inline-flex; align-items: center; gap: 8px; padding-bottom: 8px; font-size: 13px; color: var(--muted); font-weight: 600; }
.group-select select {
  background: var(--code-bg); color: var(--ink); border: 1px solid var(--line-strong); border-radius: var(--radius);
  padding: 7px 10px; font-size: 14px; max-width: 280px;
}
.group-form { align-items: stretch; }
.group-form .field { min-width: 120px; }
.pin-list .num { text-align: right; white-space: nowrap; }

/* ── 홈: 유닛 카드 ── */
.home-head { display: flex; justify-content: space-between; align-items: end; gap: 16px; flex-wrap: wrap; }
.home-head h1 { font-size: 26px; }
.home-progress { display: flex; align-items: center; gap: 12px; margin-top: 10px; font-size: 14px; color: var(--muted); }
.home-progress b { color: var(--accent); font-family: var(--font-en); }
.home-progress .meter-bar { width: 180px; }
.track-tabs { display: inline-flex; gap: 4px; padding: 4px; background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); }
.track-tabs button {
  border: 0; background: transparent; min-height: 36px; padding: 0 16px; border-radius: 4px; cursor: pointer;
  font: 600 14px/1 var(--font-en); color: var(--muted); display: inline-flex; align-items: center; gap: 6px;
}
.track-tabs button:hover { color: var(--ink); }
.track-tabs button[aria-selected="true"] { background: var(--accent); color: var(--accent-ink); }
.track-tabs .soon { font: 500 10px/1 var(--font-body); padding: 3px 5px; border-radius: 999px; border: 1px solid currentColor; opacity: .75; }

.today-line { display: flex; align-items: center; gap: 16px; padding: 14px 18px; flex-wrap: wrap; }
.today-meta { display: grid; gap: 4px; }
.today-meta b { font-size: 16px; }
.today-chips { list-style: none; margin: 0; padding: 0; display: flex; gap: 6px; flex-wrap: wrap; }
.today-chips a {
  display: inline-block; padding: 4px 10px; border-radius: 999px; border: 1px solid var(--line-strong);
  font: 500 13px/1.4 var(--font-mono); color: var(--ink-2); text-decoration: none;
}
.today-chips a:hover { border-color: var(--accent); color: var(--ink); }
.today-chips a.done { border-color: transparent; background: var(--pass-soft); color: var(--pass); }
.today-chips a.done::before { content: "✓ "; }
.today-go { margin-left: auto; max-width: 100%; }
.today-go .mono { opacity: .7; }
.today-clear { margin-left: auto; color: var(--pass); font-weight: 600; }

.part { display: grid; gap: 12px; }
.part-title { font-size: 15px; color: var(--muted); font-weight: 600; }
.ucards { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 12px; }
.ucard { padding: 16px 18px; display: grid; gap: 12px; align-content: space-between; }
.ucard-link { text-decoration: none; color: var(--ink); display: grid; gap: 6px; }
.ucard-link h3 { font-size: 17px; }
.ucard-link:hover h3 { color: var(--accent); }
.unit-num { font: 600 12px/1 var(--font-en); letter-spacing: .14em; color: var(--muted); text-transform: uppercase; }
.ucard-bar, .meter-bar { height: 4px; background: var(--surface-3); border-radius: 999px; overflow: hidden; display: block; }
.ucard-bar span { display: block; height: 100%; background: var(--accent); }
.ucard.complete .ucard-bar span { background: var(--pass); }
.ucard-foot { display: flex; align-items: center; justify-content: space-between; gap: 8px; }
.ucard-count { font: 500 13px/1 var(--font-en); color: var(--muted); font-variant-numeric: tabular-nums; }
.soon-panel { padding: 28px; display: grid; gap: 10px; justify-items: start; }
.soon-panel p { margin: 0; }
@media (max-width: 900px) { .ucards { grid-template-columns: repeat(2, minmax(0, 1fr)); } }
@media (max-width: 560px) {
  .ucards { grid-template-columns: minmax(0, 1fr); gap: 8px; }
  .ucard { grid-template-columns: minmax(0, 1fr) auto; align-items: center; gap: 8px 12px; padding: 12px 14px; }
  .ucard-link h3 { font-size: 16px; }
  .ucard-bar { grid-column: 1 / -1; grid-row: 2; }
  .ucard-foot { grid-column: 2; grid-row: 1; flex-direction: column; align-items: end; }
  .home-head h1 { font-size: 21px; }
  .today-go { margin-left: 0; width: 100%; }
}

/* ── 유닛 페이지 ── */
.page.unit-page { max-width: 760px; gap: 20px; }
.unit-hero { display: grid; gap: 8px; }
.unit-hero h1 { font-size: 28px; }
.unit-hero p { margin: 0; }
.unit-actions { display: flex; align-items: center; gap: 14px; margin-top: 6px; }
.plist.simple { list-style: none; margin: 0; padding: 0; }
.plist.simple li + li { border-top: 1px solid var(--line); }
.srow { display: flex; align-items: center; gap: 14px; padding: 14px 18px; text-decoration: none; color: var(--ink); }
.srow:hover { background: var(--surface-2); }
.srow:hover .ptitle { color: var(--accent); }
.srow .pid { font: 500 13px/1 var(--font-mono); color: var(--muted); width: 34px; flex: none; }
.srow .ptitle { flex: 1; min-width: 0; font-weight: 500; }
.st { width: 20px; flex: none; text-align: center; font-weight: 700; }
.st-solved { color: var(--pass); }
.st-tried { color: var(--accent); font-size: 20px; line-height: 1; }
.st-none { color: var(--subtle); }
.pmark { font-size: 12px; color: var(--muted); border: 1px solid var(--line-strong); border-radius: 999px; padding: 1px 8px; }
.pmark.challenge { color: var(--accent); border-color: rgba(200,255,61,.35); }
.unit-nav { display: flex; justify-content: space-between; gap: 8px; flex-wrap: wrap; }

/* ── 개념 퀴즈 ── */
.page.quiz-page { max-width: 860px; gap: 20px; }
.quiz-head { display: grid; gap: 10px; }
.quiz-head h1 { font-size: 28px; }
.quiz-head p { margin: 0; }
.quiz-list { list-style: none; margin: 0; padding: 0; display: grid; gap: 14px; }
.quiz-q { padding: 18px 20px; display: grid; gap: 12px; }
.quiz-q.ok::before { background: linear-gradient(90deg, var(--pass), transparent 60%); }
.quiz-q.no::before { background: linear-gradient(90deg, var(--fail), transparent 60%); }
.quiz-q-head { display: flex; gap: 8px; align-items: center; }
.quiz-no { font: 700 18px/1 var(--font-en); color: var(--accent); }
.quiz-text { margin: 0; font-weight: 600; font-size: 16px; }
.quiz-q .guide-code { margin: 0; }
.ox { display: flex; gap: 10px; }
.ox-btn {
  width: 76px; height: 56px; border: 1px solid var(--line-strong); background: var(--surface-2); border-radius: var(--radius);
  font: 700 24px/1 var(--font-en); color: var(--ink-2); cursor: pointer;
}
.ox-btn:hover:not(:disabled) { border-color: var(--accent); }
.ox-btn[aria-checked="true"] { background: var(--accent); color: var(--accent-ink); border-color: var(--accent); }
.ox-btn:disabled { cursor: default; }
.choices { display: grid; gap: 8px; }
.choice {
  display: flex; gap: 10px; align-items: center; padding: 10px 12px; cursor: pointer;
  border: 1px solid var(--line); border-radius: var(--radius); background: var(--surface-2);
}
.choice input { accent-color: #c8ff3d; width: 16px; height: 16px; flex: none; margin: 0; }
.choice:has(input:checked) { border-color: var(--accent); background: var(--accent-soft); }
.choice.right { border-color: var(--pass); background: var(--pass-soft); }
.choice.wrong { border-color: var(--fail); background: var(--fail-soft); }
.choice-no { font: 600 13px/1 var(--font-en); color: var(--muted); }
.short {
  width: 100%; min-height: 46px; padding: 0 12px; background: var(--code-bg);
  border: 1px solid var(--line-strong); border-radius: var(--radius); font-family: var(--font-mono);
}
.short:focus { border-color: var(--accent); outline: none; }
.quiz-feedback { display: grid; gap: 4px; padding: 10px 12px; border-radius: var(--radius); font-size: 14px; }
.quiz-feedback.ok { background: var(--pass-soft); }
.quiz-feedback.ok b { color: var(--pass); }
.quiz-feedback.no { background: var(--fail-soft); }
.quiz-feedback.no b { color: var(--fail); }
.quiz-actions { position: sticky; bottom: 12px; z-index: 5; display: flex; align-items: center; gap: 10px; padding: 12px 16px; flex-wrap: wrap; }
.quiz-actions .spacer { flex: 1; }

/* ── 제공 파일 ── */
.file-card { border: 1px solid var(--line); border-radius: var(--radius); overflow: hidden; margin-top: 8px; }
.file-name { padding: 6px 10px; background: var(--surface-2); font-size: 12px; }
.file-card pre { margin: 0; padding: 8px 10px; background: var(--code-bg); overflow: auto; font-size: 13px; }