* { margin: 0; padding: 0; box-sizing: border-box; }

:root {
  --bg: #12151c;
  --card: #1a2030;
  --card2: #212940;
  --line: #2e3852;
  --text: #e8ecf5;
  --dim: #9aa5bd;
  --red: #ff5252;
  --green: #4cd97b;
  --amber: #ffc233;
  --blue: #5b8cff;
}

body {
  background: var(--bg);
  color: var(--text);
  font-family: 'Apple SD Gothic Neo', 'Pretendard', 'Noto Sans KR', sans-serif;
  line-height: 1.6;
}

header {
  background: linear-gradient(135deg, #1c2338 0%, #251a2e 100%);
  border-bottom: 1px solid var(--line);
  padding: 20px 0;
}
.head-inner {
  max-width: 860px; margin: 0 auto; padding: 0 20px;
  display: flex; justify-content: space-between; align-items: center; gap: 16px;
}
h1 { font-size: 20px; }
.sub { color: var(--dim); font-size: 13px; margin-top: 4px; }
.stats {
  background: var(--card2); border: 1px solid var(--line);
  padding: 8px 14px; border-radius: 20px; font-size: 13px; white-space: nowrap;
}

main { max-width: 860px; margin: 0 auto; padding: 20px; }

.toolbar { display: flex; gap: 10px; margin-bottom: 16px; }
select {
  background: var(--card); color: var(--text); border: 1px solid var(--line);
  border-radius: 8px; padding: 10px 14px; font-size: 14px; flex: 1;
}
.btn {
  background: var(--card2); color: var(--text); border: 1px solid var(--line);
  border-radius: 8px; padding: 10px 20px; font-size: 14px; cursor: pointer;
  font-weight: 600;
}
.btn:hover { border-color: var(--blue); }
.btn.primary { background: var(--blue); border-color: var(--blue); color: #fff; }
.btn.primary:hover { filter: brightness(1.1); }

.card {
  background: var(--card); border: 1px solid var(--line);
  border-radius: 14px; padding: 24px;
}
.card-head { display: flex; align-items: center; gap: 8px; margin-bottom: 14px; flex-wrap: wrap; }
.type-badge {
  background: rgba(91, 140, 255, .15); color: var(--blue);
  border: 1px solid rgba(91, 140, 255, .4);
  font-size: 12px; padding: 3px 10px; border-radius: 12px; font-weight: 700;
}
.mode { font-size: 12px; padding: 3px 10px; border-radius: 12px; font-weight: 700; }
.mode.ok { background: rgba(76, 217, 123, .15); color: var(--green); border: 1px solid rgba(76, 217, 123, .4); }
.mode.not { background: rgba(255, 82, 82, .15); color: var(--red); border: 1px solid rgba(255, 82, 82, .4); }
.seed { margin-left: auto; color: var(--dim); font-size: 12px; }

.scenario { font-size: 15px; margin-bottom: 14px; }

.obs {
  background: var(--card2); border: 1px solid var(--line);
  border-radius: 10px; padding: 12px 16px; margin-bottom: 14px;
}
.obs-title { font-size: 12px; color: var(--dim); font-weight: 700; margin-bottom: 6px; }
.obs ul { list-style: none; }
.obs li { font-size: 14px; padding: 2px 0; }
.obs li::before { content: '· '; color: var(--blue); font-weight: 700; }

/* ── 패널 시각화 ── */
.panel {
  background: #0d1017; border: 2px solid #39445f; border-radius: 12px;
  padding: 16px; margin-bottom: 16px;
}
.panel-title {
  text-align: center; font-size: 13px; font-weight: 800; letter-spacing: 2px;
  color: var(--dim); border-bottom: 1px dashed var(--line);
  padding-bottom: 10px; margin-bottom: 14px;
}
.lamp-row { display: flex; gap: 14px; flex-wrap: wrap; justify-content: center; margin-bottom: 14px; }
.lamp-unit { display: flex; flex-direction: column; align-items: center; gap: 5px; }
.lamp-unit span { font-size: 11px; color: var(--dim); }
.lamp {
  width: 26px; height: 26px; border-radius: 50%;
  border: 2px solid #3a4258; background: #1c2230;
}
.lamp.red.on { background: var(--red); border-color: #ff8a8a; box-shadow: 0 0 14px rgba(255, 82, 82, .8); }
.lamp.green.on { background: var(--green); border-color: #8ef0af; box-shadow: 0 0 14px rgba(76, 217, 123, .7); }
.lamp.amber.on { background: var(--amber); border-color: #ffd97a; box-shadow: 0 0 14px rgba(255, 194, 51, .7); }
.lamp.blink { animation: blink 1s steps(1) infinite; }
@keyframes blink { 50% { background: #1c2230; box-shadow: none; } }
.voltmeter {
  min-width: 52px; height: 26px; border-radius: 5px; border: 2px solid #3a4258;
  background: #101623; color: var(--green); font-family: monospace; font-size: 14px;
  display: flex; align-items: center; justify-content: center; font-weight: 700;
}

.zone-label { font-size: 11px; color: var(--dim); font-weight: 700; margin: 10px 0 6px; }
.zone-row, .sw-row { display: flex; gap: 8px; flex-wrap: wrap; }
.zone {
  display: flex; align-items: center; gap: 6px; font-size: 12px;
  border: 1px solid var(--line); border-radius: 6px; padding: 4px 9px; color: var(--dim);
}
.zone i {
  width: 10px; height: 10px; border-radius: 50%; background: #1c2230; border: 1px solid #3a4258;
}
.zone.on { color: var(--text); border-color: rgba(255, 82, 82, .5); }
.zone.on i { background: var(--red); box-shadow: 0 0 8px rgba(255, 82, 82, .8); border-color: #ff8a8a; }

.sw {
  border: 1px solid var(--line); border-radius: 6px; padding: 4px 9px;
  font-size: 12px; display: flex; flex-direction: column; align-items: center; min-width: 64px;
}
.sw b { color: var(--dim); font-weight: 600; }
.sw em { font-style: normal; color: var(--green); font-weight: 700; }
.sw.ab { border-color: rgba(255, 194, 51, .6); background: rgba(255, 194, 51, .07); }
.sw.ab em { color: var(--amber); }

.bell-row { display: flex; gap: 10px; margin-top: 12px; flex-wrap: wrap; }
.bell {
  font-size: 12px; border: 1px solid var(--line); border-radius: 6px;
  padding: 4px 10px; color: var(--dim);
}
.bell.ring { color: var(--amber); border-color: rgba(255, 194, 51, .5); }

.pump-row { display: flex; gap: 14px; flex-wrap: wrap; }
.ctrl-box {
  flex: 1; min-width: 220px; border: 1px solid var(--line); border-radius: 10px; padding: 12px;
}
.ctrl-title { font-size: 12px; color: var(--dim); font-weight: 700; margin-bottom: 8px; }
.selector { display: flex; gap: 6px; }
.selector span {
  flex: 1; text-align: center; font-size: 13px; padding: 7px 4px;
  border: 1px solid var(--line); border-radius: 6px; color: var(--dim);
}
.selector .sel {
  background: rgba(91, 140, 255, .18); border-color: var(--blue);
  color: var(--text); font-weight: 700;
}
.ctrl-note { font-size: 11px; color: var(--dim); margin-top: 8px; }

/* ── 문제/선지 ── */
.q-text { font-size: 16px; font-weight: 700; margin: 18px 0 12px; }
.q-text u { text-decoration-color: var(--red); }

.opt {
  display: flex; align-items: flex-start; gap: 10px;
  background: var(--card2); border: 1px solid var(--line);
  border-radius: 10px; padding: 12px 14px; margin-bottom: 8px; cursor: pointer;
  transition: border-color .15s;
}
.opt:hover { border-color: var(--blue); }
.opt input { margin-top: 4px; accent-color: var(--blue); width: 16px; height: 16px; }
.opt .num { font-weight: 700; color: var(--blue); }
.opt .txt { flex: 1; font-size: 14.5px; }
.opt .mark { font-size: 12px; font-weight: 800; white-space: nowrap; }
.opt .mark.good { color: var(--green); }
.opt .mark.bad { color: var(--red); }
.opt.ans { border-color: rgba(76, 217, 123, .55); background: rgba(76, 217, 123, .06); }

.explain {
  display: none; margin: -2px 0 10px; padding: 10px 14px 10px 40px;
  font-size: 13px; color: var(--dim);
}
.explain.show { display: block; }
.explain .ox { font-weight: 800; display: block; margin-bottom: 4px; }
.explain .ox.o { color: var(--green); }
.explain .ox.x { color: var(--red); }
.explain .rule { margin-top: 3px; }
.explain .rule b { color: var(--blue); margin-right: 4px; }

.result { display: none; border-radius: 10px; padding: 14px 16px; font-weight: 700; margin: 14px 0; }
.result.show { display: block; }
.result.pass { background: rgba(76, 217, 123, .12); border: 1px solid rgba(76, 217, 123, .5); color: var(--green); }
.result.fail { background: rgba(255, 82, 82, .12); border: 1px solid rgba(255, 82, 82, .5); color: var(--red); }

.btn-row { display: flex; gap: 10px; margin-top: 14px; }

footer {
  max-width: 860px; margin: 0 auto; padding: 10px 20px 40px;
  color: var(--dim); font-size: 12px;
}

@media (max-width: 560px) {
  header { padding: 12px 0; }
  .head-inner { flex-direction: row; align-items: center; gap: 8px; }
  h1 { font-size: 15px; flex: 1; min-width: 0; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
  .sub { display: none; }
  .stats { font-size: 12px; padding: 6px 10px; }

  main { padding: 12px; }
  .toolbar { flex-direction: row; margin-bottom: 12px; }
  select { padding: 12px; }
  .toolbar .btn { white-space: nowrap; }

  .card { padding: 16px 14px; border-radius: 12px; }
  .scenario { font-size: 14.5px; }
  .q-text { font-size: 15px; }

  /* 터치 타깃 확대 */
  .opt { padding: 14px 12px; gap: 8px; }
  .opt input { width: 20px; height: 20px; margin-top: 2px; }
  .opt .txt { font-size: 14px; }

  .panel { padding: 12px 10px; }
  .lamp-row { gap: 10px; }
  .lamp { width: 22px; height: 22px; }
  .lamp-unit span { font-size: 10px; }
  .zone, .sw { font-size: 11px; }

  /* 엄지 범위 하단 고정 액션 바 */
  .btn-row {
    position: sticky;
    bottom: 0;
    margin: 14px -14px calc(-16px - env(safe-area-inset-bottom));
    padding: 12px 14px calc(12px + env(safe-area-inset-bottom));
    background: linear-gradient(to top, var(--card) 75%, transparent);
    border-radius: 0 0 12px 12px;
  }
  .btn-row .btn { flex: 1; min-height: 48px; font-size: 16px; }

  footer { font-size: 11px; padding-bottom: calc(24px + env(safe-area-inset-bottom)); }
}