: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:#2f54d6; /* 달력 블루 */
  --accent-soft:#e9eefc;
  --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{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;flex-shrink:0}
.btn:hover{background:var(--hover)}
.btn--solid{background:var(--ink);color:#fff;border:none;font-weight:500}
.btn--solid:hover{background:var(--ink-hover)}
.btn--wide{height:44px;font-size:14px}
.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);margin:0}

/* ---------- Layout ---------- */
.wrap{width:100%;max-width:1080px;margin:0 auto;padding:28px 28px 64px;display:flex;flex-direction:column;gap:24px}
.tabs{display:flex;gap:4px;background:var(--track);padding:4px;border-radius:999px;align-self:flex-start;max-width:100%}
.tab{height:38px;padding:0 20px;border:none;background:transparent;border-radius:999px;font-size:14px;color:var(--sub);cursor:pointer;white-space:nowrap;transition:background .15s,color .15s}
.tab:hover{color:var(--ink)}
.tab.is-active{background:var(--ink);color:#fff;font-weight:500}

.panel{display:grid;grid-template-columns:minmax(0,380px) minmax(0,1fr);gap:24px;align-items:start;animation:fade .25s ease}
.panel--narrow{grid-template-columns:minmax(0,1fr) minmax(0,1fr)}
@keyframes fade{from{opacity:0;transform:translateY(6px)}to{opacity:1;transform:none}}
.col{display:flex;flex-direction:column;gap:20px;min-width:0}

.card{background:var(--panel);border:1px solid var(--line);border-radius:16px;padding:20px}
.form{display:flex;flex-direction:column;gap:16px}
.field{display:flex;flex-direction:column;gap:6px;min-width:0}
.field label{font-size:13px;color:var(--ink-2)}
.field .text-input{width:100%}
.row{display:flex;gap:8px}
.row .text-input{flex:1}
.check{display:flex;align-items:flex-start;gap:8px;font-size:13px;line-height:1.5;cursor:pointer}
.check input{width:16px;height:16px;margin:2px 0 0;accent-color:var(--accent);flex-shrink:0}
.check em{font-style:normal;color:var(--muted)}
.check--sm{font-size:12px;color:var(--ink-2)}
.check--sm input{margin-top:1px}

/* ---------- Tear-off sheet ---------- */
.sheet{position:relative;background:var(--panel);border-radius:18px;box-shadow:0 1px 2px rgba(0,0,0,.05),0 22px 50px rgba(30,40,80,.12);padding-top:14px;overflow:hidden}
.sheet::after{content:"";position:absolute;left:0;right:0;bottom:0;height:10px;background:radial-gradient(circle at 8px 10px,var(--bg) 6px,transparent 6.5px) 0 0/16px 10px repeat-x}
.sheet-rings{position:absolute;top:6px;left:0;right:0;display:flex;justify-content:center;gap:60px;z-index:2}
.sheet-rings i{width:12px;height:12px;border-radius:50%;background:var(--bg);box-shadow:inset 0 1px 2px rgba(0,0,0,.25)}
.sheet-top{background:var(--accent);color:#fff;padding:26px 24px 16px;display:flex;justify-content:space-between;align-items:baseline;gap:12px;flex-wrap:wrap;margin-top:-14px}
.sheet-title{font-size:18px;font-weight:700;min-width:0;overflow-wrap:anywhere}
.sheet-date{color:rgba(255,255,255,.8)}
.sheet-body{padding:30px 24px 44px;text-align:center}
.big{font-family:var(--mono);font-weight:500;font-size:clamp(64px,13vw,128px);line-height:1;letter-spacing:-.05em;color:var(--ink)}
html[lang="en"] .big small{font-size:.24em;letter-spacing:0;margin:0 .25em;font-weight:500} /* 영어판 단위 */
.big.is-past{color:var(--sub)}
.big.is-today{color:var(--accent)}
.pop{animation:pop .35s cubic-bezier(.2,.9,.3,1.3)}
@keyframes pop{from{transform:scale(.9);opacity:.3}to{transform:none;opacity:1}}
.sheet-sub{margin-top:16px;font-size:15px;color:var(--ink-2)}
.sheet-sub b{color:var(--ink)}

.anniv{padding:18px 8px 8px}
.anniv-head{display:flex;justify-content:space-between;align-items:center;padding:0 12px 10px}
.anniv-list{list-style:none;margin:0;padding:0;max-height:360px;overflow-y:auto}
.anniv-list li{display:grid;grid-template-columns:72px minmax(0,1fr) auto;gap:12px;align-items:center;padding:10px 12px;border-radius:10px;font-size:14px}
.anniv-list li + li{border-top:1px solid var(--line-3)}
.anniv-list .a-name{font-weight:700}
.anniv-list .a-date{color:var(--ink-2);font-family:var(--mono);font-size:13px}
.anniv-list .a-d{font-family:var(--mono);font-size:13px;color:var(--accent);font-weight:500}
.anniv-list li.is-past{opacity:.45}
.anniv-list li.is-past .a-d{color:var(--muted)}
.anniv-list li.is-next{background:var(--accent-soft);border-color:transparent}
.anniv-list li.is-next + li{border-color:transparent}
.anniv-list li.is-year .a-name{color:var(--accent)}

/* ---------- Saved ---------- */
.saved{display:flex;flex-direction:column;gap:10px}
.saved-head{display:flex;justify-content:space-between;align-items:baseline}
.saved-list{list-style:none;margin:0;padding:0;display:flex;flex-direction:column;gap:8px}
.saved-item{display:flex;align-items:stretch;background:var(--panel);border:1px solid var(--line);border-radius:12px;overflow:hidden;transition:border-color .15s,transform .15s}
.saved-item:hover{border-color:var(--ink)}
.saved-item.is-current{border-color:var(--accent);box-shadow:0 0 0 2px var(--accent-soft)}
.saved-open{flex:1;min-width:0;display:flex;align-items:center;justify-content:space-between;gap:10px;padding:12px 14px;background:transparent;border:none;text-align:left;cursor:pointer}
.saved-name{font-size:14px;font-weight:500;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.saved-meta{display:block;font-family:var(--mono);font-size:11px;color:var(--muted);margin-top:2px}
.saved-d{font-family:var(--mono);font-size:16px;font-weight:500;color:var(--accent);flex-shrink:0}
.saved-d.is-past{color:var(--sub)}
.saved-del{width:40px;border:none;border-left:1px solid var(--line-3);background:transparent;color:var(--muted);cursor:pointer;font-size:16px}
.saved-del:hover{background:#fbeaea;color:#c92a2a}

/* ---------- Add / Diff ---------- */
.formula{display:flex;gap:8px;flex-wrap:wrap;align-items:center}
.num-input{width:110px;font-family:var(--mono);font-size:18px;height:44px;text-align:right}
.seg{display:flex;background:var(--soft);border-radius:999px;padding:3px;gap:2px}
.seg-btn{height:36px;padding:0 14px;background:transparent;color:var(--sub);border:none;border-radius:999px;font-size:13px;cursor:pointer}
.seg-btn.is-active{background:#fff;color:var(--ink);font-weight:500;box-shadow:0 1px 3px rgba(0,0,0,.12)}
.quick{display:flex;gap:6px;flex-wrap:wrap}
.mini{height:30px;padding:0 12px;border:1px solid var(--line-2);background:transparent;border-radius:999px;font-size:12px;cursor:pointer}
.mini:hover{background:var(--ink);color:#fff;border-color:var(--ink)}

.result-card{background:var(--accent);color:#fff;border-radius:18px;padding:26px 26px 24px;display:flex;flex-direction:column;gap:10px;min-height:220px;position:relative;overflow:hidden}
.result-card::before{content:"";position:absolute;right:-60px;bottom:-60px;width:200px;height:200px;border-radius:50%;border:30px solid rgba(255,255,255,.08)}
.result-card > *{position:relative}
.result-card .mono-label{color:rgba(255,255,255,.7)}
.result-date{font-family:var(--mono);font-size:clamp(34px,6vw,52px);font-weight:500;letter-spacing:-.03em;line-height:1.1;overflow-wrap:anywhere}
.result-date small{font-family:var(--font);font-size:20px;margin-left:6px;letter-spacing:0}
.result-sub{font-size:15px;color:rgba(255,255,255,.88)}
.facts{margin:8px 0 0;display:grid;grid-template-columns:1fr 1fr;gap:1px;background:rgba(255,255,255,.18);border-radius:12px;overflow:hidden}
.facts div{background:#2849bd;padding:12px 14px;min-width:0}
.facts dt{font-size:12px;color:rgba(255,255,255,.7)}
.facts dd{margin:4px 0 0;font-family:var(--mono);font-size:16px;font-weight:500;overflow-wrap:anywhere}

.pair{display:grid;grid-template-columns:minmax(0,1fr) auto minmax(0,1fr);gap:10px;align-items:end}
.swap{width:40px;height:40px;border-radius:50%;border:1px solid var(--line-2);background:#fff;cursor:pointer;font-size:16px;transition:transform .25s}
.swap:hover{transform:rotate(180deg);border-color:var(--ink)}

.toast{position:fixed;left:50%;bottom:28px;transform:translate(-50%,20px);background:var(--ink);color:#fff;padding:10px 18px;border-radius:999px;font-size:13px;opacity:0;pointer-events:none;transition:opacity .2s,transform .2s;z-index:10}
.toast.is-show{opacity:1;transform:translate(-50%,0)}

@media (max-width:860px){
  .panel,.panel--narrow{grid-template-columns:minmax(0,1fr);gap:16px}
  .col{display:contents}
  .sheet{order:1}.col--form .form{order:2}.anniv{order:3}.saved{order:4}
}
@media (max-width:640px){
  .topbar{padding:14px 16px}
  .wrap{padding:16px 16px 48px;gap:16px}
  .tabs{align-self:stretch}
  .tab{flex:1;padding:0 8px;font-size:13px}
  .card{padding:16px}
  .pair{grid-template-columns:minmax(0,1fr)}
  .swap{justify-self:center;transform:rotate(90deg)}
  .swap:hover{transform:rotate(270deg)}
  .facts{grid-template-columns:minmax(0,1fr)}
}
@media (prefers-reduced-motion:reduce){
  *{animation:none !important;transition:none !important}
}

/* 다크 모드 (인쇄는 라이트 그대로) */
@media screen{
  :root[data-theme="dark"]{
    color-scheme:dark;
    --bg:#131418; --surface:#18191e; --panel:#1d1e24; --panel-soft:#22232a;
    --ink:#eaebf0; --ink-hover:#ffffff; --ink-2:#c6c8d1; --sub:#9c9fab; --muted:#868995;
    --line:#2c2d35; --line-2:#373841; --line-3:#26272e; --hover:#292a32; --soft:#24252c; --track:#32333c;
    --accent:#7d98f5; --accent-soft:rgba(125,152,245,.15);
  }
  :root[data-theme="dark"] .btn--solid,:root[data-theme="dark"] .tab.is-active,
  :root[data-theme="dark"] .mini:hover,:root[data-theme="dark"] .toast{color:var(--bg)}
  :root[data-theme="dark"] .seg-btn.is-active{background:var(--line-2);box-shadow:0 1px 3px rgba(0,0,0,.4)}
  :root[data-theme="dark"] .swap{background:var(--panel);color:var(--ink)}
  :root[data-theme="dark"] .saved-del:hover{background:rgba(240,90,90,.14);color:#f08a8a}
  /* 파란 면(달력 머리 · 결과 카드)은 흰 글자가 읽히도록 진한 파랑 유지 */
  :root[data-theme="dark"] .sheet-top,:root[data-theme="dark"] .result-card{background:#3152c8}
  :root[data-theme="dark"] .facts div{background:#2a47b0}
  :root[data-theme="dark"] .sheet{box-shadow:0 22px 50px rgba(0,0,0,.4)}
  :root[data-theme="dark"] .sheet-rings i{box-shadow:inset 0 1px 2px rgba(0,0,0,.6)}
}