:root{
  --bg:#f5f4f0; --surface:#fbfbf9; --panel:#ffffff; --panel-soft:#f7f6f2;
  --ink:#1c1c1a; --ink-hover:#3a3935; --ink-2:#55534d; --sub:#7a776f; --muted:#8a877f;
  --line:#e3e1db; --line-2:#dcdad3; --line-3:#efeee9; --hover:#efeee9; --soft:#f3f2ee; --track:#ebe9e3;
  --accent:#0b7285; /* 제도용 청록 */
  --accent-soft:#e3f3f6;
  --font:"IBM Plex Sans KR",sans-serif; --mono:"JetBrains Mono",monospace;
}
*{box-sizing:border-box}
[hidden]{display:none !important}
body{margin:0;background:var(--bg);color:var(--ink);font-family:var(--font);-webkit-font-smoothing:antialiased}
button,select{font:inherit;color:inherit}
.mono-label{font-family:var(--mono);font-size:11px;letter-spacing:.12em;color:var(--muted)}
.app{min-height:calc(100vh - 48px);display:flex;flex-direction:column}
.topbar{display:flex;align-items:center;justify-content:space-between;gap:16px;padding:16px 28px;border-bottom:1px solid var(--line);background:var(--surface);flex-wrap:wrap}
.brand{display:flex;align-items:baseline;gap:14px;min-width:0;flex-wrap:wrap}
.home{font-size:13px;color:var(--ink-2);text-decoration:none}
.home:hover{color:var(--ink)}
.brand-title{font-size:17px;font-weight:700;letter-spacing:-.01em}
.btn{height:36px;padding:0 14px;background:transparent;border:1px solid var(--line-2);border-radius:999px;font-size:13px;cursor:pointer}
.text-input{height:40px;padding:0 12px;background:var(--surface);border:1px solid var(--line-2);border-radius:8px;font:inherit;font-size:14px;color:var(--ink);min-width:0}
.text-input:focus{outline:none;border-color:var(--accent);box-shadow:0 0 0 3px var(--accent-soft)}
.sr-only{position:absolute;width:1px;height:1px;overflow:hidden;clip:rect(0 0 0 0);white-space:nowrap}
.hint{font-size:12px;color:var(--muted)}

.wrap{width:100%;max-width:1180px;margin:0 auto;padding:28px 28px 64px;display:flex;flex-direction:column;gap:22px}

/* ---------- Category tabs ---------- */
.cats{display:flex;flex-wrap:wrap;gap:8px}
.cat{display:flex;align-items:center;gap:8px;height:42px;padding:0 16px 0 12px;border:1px solid var(--line-2);background:var(--panel);border-radius:999px;font-size:14px;cursor:pointer;transition:background .15s,border-color .15s,color .15s}
.cat:hover{border-color:var(--ink)}
.cat i{font-style:normal;font-family:var(--mono);font-size:11px;width:24px;height:24px;display:grid;place-items:center;border-radius:50%;background:var(--soft);color:var(--ink-2)}
.cat.is-active{background:var(--accent);border-color:var(--accent);color:#fff;font-weight:500}
.cat.is-active i{background:rgba(255,255,255,.2);color:#fff}
.cat--star{position:relative}
.cat--star::after{content:"평";position:absolute;top:-6px;right:-4px;font-size:10px;font-weight:700;background:#f59f00;color:#fff;border-radius:999px;padding:1px 5px}

.layout{display:grid;grid-template-columns:minmax(0,1fr) 340px;gap:22px;align-items:start}
.main-col{display:flex;flex-direction:column;gap:22px;min-width:0}

/* ---------- Converter ---------- */
.conv{background:var(--panel);border:1px solid var(--line);border-radius:20px;overflow:hidden;box-shadow:0 1px 2px rgba(0,0,0,.04),0 20px 44px rgba(20,60,70,.08)}
.ruler{height:26px;background:
  repeating-linear-gradient(90deg,var(--accent) 0 1px,transparent 1px 50px) 0 0/100% 18px no-repeat,
  repeating-linear-gradient(90deg,var(--accent) 0 1px,transparent 1px 25px) 0 0/100% 11px no-repeat,
  repeating-linear-gradient(90deg,rgba(11,114,133,.55) 0 1px,transparent 1px 5px) 0 0/100% 6px no-repeat,
  var(--accent-soft);border-bottom:1px solid rgba(11,114,133,.25)}
.conv-body{display:grid;grid-template-columns:minmax(0,1fr) auto minmax(0,1fr);gap:16px;align-items:center;padding:30px 28px 22px}
.side{display:flex;flex-direction:column;gap:10px;min-width:0}
.val-input{width:100%;min-width:0;height:72px;padding:0 4px;border:none;border-bottom:2px solid var(--ink);background:transparent;font-family:var(--mono);font-size:40px;font-weight:500;letter-spacing:-.03em;color:var(--ink);outline:none;transition:border-color .15s}
.val-input:focus{border-color:var(--accent)}
.val-input.flash{animation:flash .3s ease}
@keyframes flash{from{color:var(--accent)}to{color:var(--ink)}}
.unit-select{height:44px;width:100%;padding:0 36px 0 14px;border:1px solid var(--line-2);border-radius:12px;background:var(--panel-soft) url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='8'%3E%3Cpath d='M1 1l5 5 5-5' fill='none' stroke='%2355534d' stroke-width='1.6'/%3E%3C/svg%3E") no-repeat right 14px center;appearance:none;-webkit-appearance:none;font-size:14px;cursor:pointer}
.unit-select:focus{outline:none;border-color:var(--accent)}
.swap{width:48px;height:48px;border-radius:50%;border:1px solid var(--line-2);background:#fff;font-size:18px;cursor:pointer;transition:transform .3s,background .15s,color .15s}
.swap:hover{background:var(--accent);color:#fff;border-color:var(--accent);transform:rotate(180deg)}
.conv-foot{display:flex;justify-content:space-between;align-items:center;gap:12px;flex-wrap:wrap;padding:14px 28px;border-top:1px dashed var(--line-2);background:var(--panel-soft)}
.formula{font-family:var(--mono);font-size:13px;color:var(--ink-2);overflow-wrap:anywhere}
.seg{display:flex;background:var(--track);border-radius:999px;padding:3px;gap:2px}
.seg-btn{height:28px;padding:0 12px;background:transparent;color:var(--sub);border:none;border-radius:999px;font-size:12px;cursor:pointer;white-space:nowrap}
.seg-btn.is-active{background:#fff;color:var(--ink);font-weight:500;box-shadow:0 1px 3px rgba(0,0,0,.12)}

/* ---------- Quick ---------- */
.quick{display:flex;flex-direction:column;gap:10px}
.quick-list{display:flex;flex-wrap:wrap;gap:8px}
.q{display:flex;align-items:center;gap:6px;height:38px;padding:0 14px;border:1px solid var(--line-2);background:var(--panel);border-radius:999px;font-size:13px;cursor:pointer;transition:border-color .15s,background .15s}
.q:hover{border-color:var(--accent);background:var(--accent-soft)}
.q b{font-family:var(--mono);font-weight:500}
.q span{color:var(--muted);font-size:12px}

/* ---------- 평형 ---------- */
.pyeong{background:var(--ink);color:#fff;border-radius:20px;padding:24px;display:flex;flex-direction:column;gap:16px;animation:rise .3s ease}
@keyframes rise{from{opacity:0;transform:translateY(8px)}to{opacity:1;transform:none}}
.py-head{display:flex;flex-direction:column;gap:4px}
.py-head .mono-label{color:#8fd3df}
.py-head h2{margin:0;font-size:20px;letter-spacing:-.01em}
.py-presets{display:grid;grid-template-columns:1fr 1fr;gap:10px}
.py-chip{display:flex;flex-direction:column;align-items:flex-start;gap:2px;padding:14px 16px;border-radius:14px;border:1px solid rgba(255,255,255,.18);background:rgba(255,255,255,.04);color:#fff;cursor:pointer;text-align:left;transition:background .15s,border-color .15s}
.py-chip b{font-family:var(--mono);font-size:26px;font-weight:500;letter-spacing:-.02em}
.py-chip span{font-size:12px;color:#cfccc3}
.py-chip:hover{border-color:#8fd3df}
.py-chip.is-active{background:var(--accent);border-color:var(--accent)}
.py-fields{display:flex;gap:10px;flex-wrap:wrap}
.py-f{flex:1 1 140px;display:flex;align-items:center;gap:8px;font-size:13px;color:#cfccc3;min-width:0}
.py-f span{flex-shrink:0}
.py-f .text-input{flex:1;width:100%;background:rgba(255,255,255,.06);border-color:rgba(255,255,255,.2);color:#fff;font-family:var(--mono);font-size:16px;text-align:right}
.py-f em{font-style:normal}
.py-out{display:grid;grid-template-columns:minmax(0,1fr) auto minmax(0,1fr);align-items:center;gap:12px;padding:16px;border-radius:14px;background:rgba(255,255,255,.06)}
.py-out > div{display:flex;flex-direction:column;gap:4px;min-width:0}
.py-k{font-size:12px;color:#a8a59c}
.py-v{font-family:var(--mono);font-size:20px;font-weight:500;overflow-wrap:anywhere;line-height:1.3}
.py-v--accent{color:#8fd3df}
.py-v small{display:block;font-size:12px;color:#a8a59c;font-weight:400}
.py-arrow{font-family:var(--mono);color:#8fd3df;font-size:18px}
.py-note{margin:0;font-size:12px;line-height:1.7;color:#a8a59c}
.py-note b{color:#fff;font-weight:500}

/* ---------- All units ---------- */
.all{background:var(--panel);border:1px solid var(--line);border-radius:20px;padding:18px 10px 10px;position:sticky;top:20px}
.all-head{display:flex;justify-content:space-between;align-items:baseline;padding:0 10px 10px;gap:8px}
.all-list{list-style:none;margin:0;padding:0}
.all-row{width:100%;display:flex;justify-content:space-between;align-items:baseline;gap:12px;padding:10px;border:none;border-radius:10px;background:transparent;cursor:pointer;text-align:left}
.all-row:hover{background:var(--soft)}
.all-row.is-to{background:var(--accent-soft)}
.all-row.is-from{opacity:.5}
.all-name{font-size:13px;color:var(--ink-2);flex-shrink:0}
.all-val{font-family:var(--mono);font-size:14px;font-weight:500;text-align:right;overflow-wrap:anywhere;min-width:0}
.all-val small{color:var(--muted);font-weight:400;margin-left:4px}
.all-list li + li .all-row{border-top:1px solid var(--line-3);border-radius:0}
.all-list li + li .all-row:hover,.all-list li + li .all-row.is-to{border-radius:10px;border-color:transparent}

@media (max-width:920px){
  .layout{grid-template-columns:minmax(0,1fr)}
  .all{position:static}
}
@media (max-width:640px){
  .topbar{padding:14px 16px}
  .wrap{padding:16px 16px 48px;gap:16px}
  .cats{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:6px}
  .cat{justify-content:center;padding:0 6px;height:38px;font-size:13px}
  .cat i{display:none}
  .conv-body{grid-template-columns:minmax(0,1fr);padding:22px 18px 16px;gap:12px}
  .swap{justify-self:center;transform:rotate(90deg)}
  .swap:hover{transform:rotate(270deg)}
  .val-input{font-size:32px;height:60px}
  .conv-foot{padding:12px 18px}
  .pyeong{padding:18px}
  .py-out{grid-template-columns:minmax(0,1fr);gap:8px}
  .py-arrow{transform:rotate(90deg);justify-self:start}
}
@media (prefers-reduced-motion:reduce){
  *{animation:none !important;transition:none !important}
}

/* 다크 모드 (인쇄는 라이트 그대로) · 평형 변환기(pyeong-converter)도 이 파일을 함께 씀 */
@media screen{
  :root[data-theme="dark"]{
    color-scheme:dark;
    --bg:#131516; --surface:#191b1c; --panel:#1e2122; --panel-soft:#232728;
    --ink:#eaeced; --ink-hover:#ffffff; --ink-2:#c5cacc; --sub:#9da3a6; --muted:#878d90;
    --line:#2d3133; --line-2:#383d3f; --line-3:#272b2c; --hover:#2a2e30; --soft:#25292a; --track:#333839;
    --accent:#4fbfd3; --accent-soft:rgba(79,191,211,.14);
  }
  /* 청록 면은 흰 글자가 읽히도록 진한 청록 유지 */
  :root[data-theme="dark"] .cat.is-active,:root[data-theme="dark"] .py-chip.is-active{background:#0e7d92;border-color:#0e7d92}
  :root[data-theme="dark"] .py-chip.is-active span{color:#e6f4f6}
  :root[data-theme="dark"] .swap{background:var(--panel);color:var(--ink)}
  :root[data-theme="dark"] .swap:hover{background:#0e7d92;border-color:#0e7d92;color:#fff}
  :root[data-theme="dark"] .seg-btn.is-active{background:#4a5052;box-shadow:0 1px 3px rgba(0,0,0,.4)}
  :root[data-theme="dark"] .conv{box-shadow:0 20px 44px rgba(0,0,0,.35)}
  :root[data-theme="dark"] .ruler{border-bottom-color:rgba(79,191,211,.25);background:
    repeating-linear-gradient(90deg,var(--accent) 0 1px,transparent 1px 50px) 0 0/100% 18px no-repeat,
    repeating-linear-gradient(90deg,var(--accent) 0 1px,transparent 1px 25px) 0 0/100% 11px no-repeat,
    repeating-linear-gradient(90deg,rgba(79,191,211,.45) 0 1px,transparent 1px 5px) 0 0/100% 6px no-repeat,
    var(--accent-soft)}
  :root[data-theme="dark"] .unit-select{background:var(--panel-soft) url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='8'%3E%3Cpath d='M1 1l5 5 5-5' fill='none' stroke='%23c5cacc' stroke-width='1.6'/%3E%3C/svg%3E") no-repeat right 14px center}
  /* 원래 어두운 평형 판: 배경과 구분되게 한 단계 띄우고 테두리 */
  :root[data-theme="dark"] .pyeong{background:#1a2224;border:1px solid #2a3739}
}