:root {
  --bg: #f4f5f7;
  --card: #ffffff;
  --text: #1d2330;
  --muted: #5d6677;
  --line: #dde1e8;
  --accent: #1f5fbf;
  --accent-text: #ffffff;
  --mine-bg: #eaf2ff;
  --mine-line: #9dbdf0;
  --glow: rgba(31, 95, 191, 0.14);
  --ok: #1a7f45;
  --ok-bg: #e3f5ea;
  --bad: #c0392b;
  --bad-bg: #fbe7e4;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #12151b;
    --card: #1b2029;
    --text: #e6e9ef;
    --muted: #9aa3b4;
    --line: #2c3340;
    --accent: #6aa2ff;
    --accent-text: #0d1117;
    --mine-bg: #1a2740;
    --mine-line: #35588f;
    --glow: rgba(106, 162, 255, 0.16);
    --ok: #5fd08b;
    --ok-bg: #17301f;
    --bad: #ff8a7a;
    --bad-bg: #3a1d19;
  }
}
* { box-sizing: border-box; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Apple SD Gothic Neo", "Malgun Gothic", "Noto Sans KR", sans-serif;
  line-height: 1.6;
}
main { max-width: 760px; margin: 0 auto; padding: 24px 16px 56px; }
.back { font-size: 0.9rem; color: var(--muted); text-decoration: none; }
.back:hover { color: var(--accent); }
h1 { font-size: 1.6rem; margin: 8px 0 4px; }
.lead { color: var(--muted); margin: 0 0 20px; font-size: 0.95rem; }
h2 { font-size: 1.05rem; margin: 0 0 10px; }

.tabs { display: flex; gap: 4px; border-bottom: 1px solid var(--line); margin-bottom: 16px; overflow-x: auto; }
.tab {
  appearance: none; background: none; border: 0; border-bottom: 3px solid transparent;
  color: var(--muted); font: inherit; font-weight: 600;
  padding: 8px 14px; cursor: pointer; white-space: nowrap;
}
.tab[aria-selected="true"] { color: var(--accent); border-bottom-color: var(--accent); }
.tab:focus-visible { outline: 2px solid var(--accent); outline-offset: -2px; }

.card {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 16px 18px;
  margin-bottom: 14px;
}
.row { display: flex; flex-wrap: wrap; gap: 12px 18px; align-items: center; }
.field { display: flex; flex-direction: column; gap: 2px; font-size: 0.85rem; color: var(--muted); }
.field b { color: var(--text); font-weight: 600; }
select, input[type="text"], input[type="number"] {
  font: inherit; color: var(--text); background: var(--bg);
  border: 1px solid var(--line); border-radius: 8px; padding: 6px 10px;
}
input[type="range"] { accent-color: var(--accent); }

.check { font-size: 0.9rem; color: var(--muted); display: flex; align-items: center; gap: 8px; margin-top: -6px; }
#keyCountBox, #countBox, #groupLenBox { white-space: nowrap; }

button.btn {
  font: inherit; font-weight: 600; cursor: pointer;
  border: 1px solid var(--accent); color: var(--accent); background: transparent;
  border-radius: 8px; padding: 7px 16px;
}
button.btn:hover:not(:disabled), button.btn:focus-visible { background: var(--accent); color: var(--accent-text); outline: none; }
button.btn.primary { background: var(--accent); color: var(--accent-text); }
button.btn.primary:hover:not(:disabled) { filter: brightness(1.1); }
button.btn:disabled { opacity: .4; cursor: default; }

.koch { font-family: ui-monospace, Menlo, Consolas, monospace; font-size: 1.1rem; letter-spacing: .08em; word-break: break-all; }
.koch .new { color: var(--accent-text); background: var(--accent); border-radius: 4px; padding: 0 3px; }
.koch .off { color: var(--muted); opacity: .45; }

.answer-in {
  width: 100%; font-family: ui-monospace, Menlo, Consolas, monospace;
  font-size: 1.3rem; text-transform: uppercase; letter-spacing: .1em; padding: 10px 12px;
}
.result { margin-top: 12px; font-family: ui-monospace, Menlo, Consolas, monospace; font-size: 1.25rem; letter-spacing: .1em; word-break: break-all; }
.result .lab { display: block; font-family: inherit; font-size: 0.78rem; letter-spacing: 0; color: var(--muted); font-family: -apple-system, "Apple SD Gothic Neo", "Malgun Gothic", sans-serif; }
.result .c { border-radius: 3px; padding: 0 1px; }
.result .c.ok { color: var(--ok); background: var(--ok-bg); }
.result .c.bad { color: var(--bad); background: var(--bad-bg); }
.score { font-weight: 700; }
.hint { color: var(--muted); font-size: 0.88rem; }
.status { min-height: 1.5em; color: var(--muted); font-size: 0.9rem; }

.keybtn, .padbtn {
  width: 100%; border-radius: 14px;
  border: 2px solid var(--accent); background: var(--mine-bg); color: var(--accent);
  font: inherit; font-size: 1.1rem; font-weight: 700;
  touch-action: none; user-select: none; -webkit-user-select: none; cursor: pointer;
}
.keybtn { min-height: 96px; }
.keybtn small { display: block; font-size: 0.8rem; font-weight: 500; opacity: .8; }
.keybtn.down, .padbtn.down { background: var(--accent); color: var(--accent-text); }
.paddles { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; margin-top: 10px; }
.padbtn { min-height: 96px; display: flex; flex-direction: column; align-items: center; justify-content: center; }
.padbtn b { font-size: 1.8rem; line-height: 1.1; font-family: ui-monospace, Menlo, Consolas, monospace; }
.padbtn span { font-size: 0.85rem; font-weight: 500; }
.decoded { height: 3.2em; line-height: 1.6; overflow-y: auto; font-family: ui-monospace, Menlo, Consolas, monospace; font-size: 1.5rem; letter-spacing: .1em; word-break: break-all; }   /* 두 줄 높이로 고정: 글자가 늘어도 아래 키가 밀리지 않게 */
.pattern { height: 1.6em; line-height: 1.6; overflow: hidden; font-family: ui-monospace, Menlo, Consolas, monospace; font-size: 1.3rem; color: var(--accent); letter-spacing: .15em; }   /* 한 줄 높이로 고정 */
.target .now { background: var(--accent); color: var(--accent-text); border-radius: 4px; }
.target { font-family: ui-monospace, Menlo, Consolas, monospace; font-size: 1.4rem; letter-spacing: .1em; overflow-wrap: anywhere; }

.chart { display: grid; gap: 8px; grid-template-columns: repeat(auto-fill, minmax(104px, 1fr)); margin-bottom: 8px; }
.cell {
  font: inherit; color: var(--text); text-align: center; cursor: pointer;
  background: var(--card); border: 1px solid var(--line); border-radius: 10px; padding: 8px 4px;
}
.cell:hover, .cell:focus-visible { border-color: var(--accent); outline: none; box-shadow: 0 4px 12px var(--glow); }
.cell .ch { font-size: 1.3rem; font-weight: 700; display: block; }
.cell .code { font-family: ui-monospace, Menlo, Consolas, monospace; color: var(--accent); letter-spacing: .12em; font-size: 1rem; }

footer { margin-top: 32px; padding-top: 14px; border-top: 1px solid var(--line); font-size: 0.85rem; color: var(--muted); text-align: center; }
[hidden] { display: none !important; }

/* 모바일: 입력창이 키보드 위 영역에 보이도록 머리말을 줄인다 */
@media (max-width: 600px) {
  main { padding: 12px 16px 40px; }
  h1 { font-size: 1.35rem; margin: 4px 0 8px; }
  .lead { display: none; }
  .tabs { margin-bottom: 10px; }
  .card { padding: 12px 14px; margin-bottom: 10px; }
  button.btn { padding: 7px 11px; }
  .keyhint { display: none; }
  .top { display: flex; align-items: baseline; gap: 12px; }
  .top h1 { margin: 0 0 8px; }
  .optrow { gap: 8px 14px; }
  .optrow .field { flex-direction: row; align-items: center; gap: 8px; }
  /* 패들(왼쪽·오른쪽) 사이에 스트레이트 키를 두고 한 줄로 */
  .keys { display: grid; grid-template-columns: 1fr 1.3fr 1fr; gap: 8px; margin-top: 8px; }
  .paddles { display: contents; }
  #padL { order: 1; }
  .keybtn { order: 2; margin-top: 0; }
  #padR { order: 3; }
  .keybtn, .padbtn { min-height: 92px; }
  .keybtn small { display: none; }
  .decoded { font-size: 1.3rem; }
  .pattern { font-size: 1.15rem; }
  .target { font-size: 1.2rem; }
}

/* 키잉 연습: 키를 길게 누를 때 글자 선택·길게 누르기 메뉴가 뜨지 않게 한다 */
#p-key {
  -webkit-user-select: none; user-select: none;
  -webkit-touch-callout: none;
  -webkit-tap-highlight-color: transparent;
}
#p-key select { -webkit-user-select: auto; user-select: auto; }

/* 모바일: 더블탭 확대·길게 누르기 제스처 방지, 웹 앱(홈 화면 설치) 대응 */
html { -webkit-text-size-adjust: 100%; touch-action: manipulation; }
main {
  padding-left: max(16px, env(safe-area-inset-left));
  padding-right: max(16px, env(safe-area-inset-right));
  padding-bottom: max(56px, calc(env(safe-area-inset-bottom) + 24px));
}
@media (display-mode: standalone) {
  .back { display: none; }            /* 앱으로 열면 사이트 밖(../)으로 나가는 링크는 숨긴다 */
  main { padding-top: max(16px, env(safe-area-inset-top)); }
}