:root {
  --bg: #f6f6f4; --card: #ffffff; --ink: #1d1d1f; --mute: #66666c; --line: #e2e2de; --soft: #f0f0ec;
  --acc: #2f5bd3; --acc-ink: #ffffff; --ok: #1f8a4c; --warn: #a15c00; --err: #b3261e; --on: #e8eefc;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #141416; --card: #1c1c1f; --ink: #ececee; --mute: #9d9da3; --line: #2e2e33; --soft: #232327;
    --acc: #7d9bff; --acc-ink: #10131c; --ok: #4cc27e; --warn: #e3a447; --err: #ff8a80; --on: #26304a;
  }
}
* { box-sizing: border-box; }
body { margin: 0; background: var(--bg); color: var(--ink); font: 15px/1.6 system-ui, "Malgun Gothic", "Apple SD Gothic Neo", sans-serif; }
h1 { font-size: 20px; margin: 0 0 8px; }
h3 { font-size: 14px; margin: 14px 0 6px; color: var(--mute); font-weight: 600; }
button { font: inherit; cursor: pointer; padding: 6px 14px; border-radius: 8px; border: 1px solid var(--line); background: var(--card); color: var(--ink); }
button:disabled { opacity: .45; cursor: not-allowed; }
button.primary { background: var(--acc); color: var(--acc-ink); border-color: var(--acc); }
button.link { border: 0; background: none; color: var(--acc); padding: 0 4px; }
button.block { display: block; width: 100%; margin-top: 10px; }
input[type=text], input[type=password], textarea { width: 100%; font: inherit; padding: 6px 8px; border: 1px solid var(--line); border-radius: 6px; background: var(--card); color: var(--ink); }
textarea { resize: vertical; }
.mute { color: var(--mute); }
.small { font-size: 13px; }
.pad { padding: 16px; }
.err { color: var(--err); }
.ok { color: var(--ok); }
.warn { color: var(--warn); font-weight: 600; }

.top { display: flex; justify-content: space-between; align-items: center; gap: 12px; padding: 10px 16px; border-bottom: 1px solid var(--line); background: var(--card); position: sticky; top: 0; z-index: 3; }
.brand { font-weight: 700; }
.brand .mute { font-weight: 400; font-size: 13px; margin-left: 6px; }
.app { max-width: 1500px; margin: 0 auto; padding: 16px; position: relative; z-index: 1; }

/* 채점자 코드 워터마크(화면을 찍으면 누구 화면인지 남는다) */
.mark { position: fixed; inset: 0; z-index: 2; pointer-events: none; display: flex; flex-wrap: wrap; gap: 90px 120px; padding: 40px; opacity: .06; overflow: hidden; transform: rotate(-18deg) scale(1.3); user-select: none; }
.mark span { font-size: 22px; font-weight: 700; white-space: nowrap; color: var(--ink); }

.card { background: var(--card); border: 1px solid var(--line); border-radius: 12px; padding: 14px 16px; margin: 0 0 12px; }
.narrow { max-width: 760px; margin: 24px auto; }
.pledge li { margin: 0 0 8px; }
.check { display: flex; gap: 8px; align-items: flex-start; margin: 12px 0; font-weight: 600; }
.actions { display: flex; gap: 8px; justify-content: flex-end; flex-wrap: wrap; margin: 12px 0 0; }

.layout { display: grid; grid-template-columns: 240px minmax(0, 1fr); gap: 16px; align-items: start; }
.side { position: sticky; top: 64px; max-height: calc(100vh - 80px); overflow: auto; }
.stage { background: var(--card); border: 1px solid var(--line); border-radius: 12px; padding: 12px; font-size: 13px; margin-bottom: 10px; }
.stage.s2 { border-color: var(--acc); }
.stage.done { border-color: var(--ok); }
.bar { height: 6px; background: var(--soft); border-radius: 3px; margin: 10px 0 4px; overflow: hidden; }
.bar i { display: block; height: 100%; width: 0; background: var(--acc); }
.tasks { list-style: none; margin: 0; padding: 0; }
.tasks button { width: 100%; display: flex; justify-content: space-between; border: 0; border-radius: 6px; padding: 4px 8px; background: none; font-size: 13px; text-align: left; }
.tasks button em { font-style: normal; color: var(--mute); font-size: 12px; }
.tasks button.done em { color: var(--ok); }
.tasks button.draft em { color: var(--warn); }
.tasks button.cur { background: var(--on); font-weight: 700; }

.taskhead { font-size: 13px; color: var(--mute); margin: 0 0 8px; }
.cols { display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); gap: 16px; align-items: start; }
.col-left { background: var(--card); border: 1px solid var(--line); border-radius: 12px; padding: 4px 16px 16px; }
.col-right { position: sticky; top: 64px; max-height: calc(100vh - 80px); overflow: auto; }
.text { white-space: pre-wrap; word-break: break-word; background: var(--soft); border-radius: 8px; padding: 10px 12px; }
.text.resp { background: var(--card); border: 1px solid var(--line); }
details { margin-top: 12px; }
summary { cursor: pointer; color: var(--mute); }
.ref dl { margin: 0; }
.ref dt { font-size: 13px; color: var(--mute); margin-top: 8px; }
.ref dd { margin: 2px 0 0; }
.ref ul { margin: 0; padding-left: 18px; }
blockquote { margin: 4px 0; padding: 6px 10px; border-left: 3px solid var(--line); background: var(--soft); border-radius: 0 6px 6px 0; white-space: pre-wrap; }

fieldset.crit { border: 1px solid var(--line); border-radius: 12px; background: var(--card); padding: 10px 14px 14px; margin: 0 0 12px; }
fieldset.crit legend { font-weight: 700; padding: 0 6px; }
.rubric { margin: 0 0 8px; font-size: 13px; }
.lab { display: block; font-size: 13px; color: var(--mute); margin: 8px 0 4px; }
.seg { display: inline-flex; border: 1px solid var(--line); border-radius: 8px; overflow: hidden; }
.seg label { padding: 5px 14px; border-right: 1px solid var(--line); cursor: pointer; min-width: 52px; text-align: center; }
.seg label:last-child { border-right: 0; }
.seg label.on { background: var(--acc); color: var(--acc-ink); font-weight: 700; }
.seg input { position: absolute; opacity: 0; pointer-events: none; }
.seg input:focus-visible + * , .seg label:focus-within { outline: 2px solid var(--acc); outline-offset: -2px; }
.tool { border-top: 1px dashed var(--line); margin-top: 12px; padding-top: 4px; }
.tool ul { margin: 0; padding-left: 18px; font-size: 13px; }
.tool p.mute { font-size: 13px; margin: 6px 0; }
.msg { min-height: 1.4em; text-align: right; font-size: 13px; }

/* 관리 화면 */
table { border-collapse: collapse; width: 100%; font-size: 13px; }
th, td { border-bottom: 1px solid var(--line); padding: 6px; text-align: left; vertical-align: top; }
td.num, th.num { text-align: right; font-variant-numeric: tabular-nums; }
.url { font: 12px ui-monospace, Consolas, monospace; word-break: break-all; }
.scroll { overflow-x: auto; }

@media (max-width: 1000px) {
  .cols { grid-template-columns: minmax(0, 1fr); }
  .col-right { position: static; max-height: none; }
}
@media (max-width: 720px) {
  .app { padding: 12px 16px; }
  .layout { grid-template-columns: minmax(0, 1fr); }
  .side { position: static; max-height: 240px; }
  .brand .mute { display: none; }
  .top { position: static; }
  .seg label { padding: 5px 10px; min-width: 44px; }
}