/* ============================================================
   mandarin.blog — 字帖 / Copybook
   Warm ivory paper, warm ink, one scoped cinnabar. The signature
   is the 田字格 practice square: real copybooks print the grid in
   light red, so the cinnabar IS the grid — structural, not decor.
   Fonts via Google Fonts + local Kaiti (see default.hbs).
   ============================================================ */
:root{
  --paper:#FAF6EE;        /* warm ivory ground */
  --paper2:#F3ECDF;       /* faint panel wash */
  --ink:#1F1A15;          /* warm brown-black */
  --ink-soft:#7B7268;     /* warm greige — notation layer */
  --ink-faint:#A99E90;    /* fainter still */
  --line:#E7DFD3;         /* warm hairline */
  --white:#FFFFFF;        /* crisp square fill */
  --cinnabar:#B1382B;     /* scoped red */
  --grid-edge:rgba(177,56,43,.42);  /* practice-square border */
  --grid-cross:rgba(177,56,43,.30); /* dashed cross */

  --han:"Kaiti SC","STKaiti","KaiTi","Noto Serif SC","Songti SC","STSong",serif;
  --reading:'Fraunces',Georgia,'Times New Roman',serif;
  --mono:'IBM Plex Mono',ui-monospace,'SF Mono',monospace;
}
*{box-sizing:border-box;}
html{-webkit-text-size-adjust:100%;scroll-behavior:smooth;}
body{margin:0;background:var(--paper);color:var(--ink);
  font-family:var(--reading);font-size:18px;line-height:1.68;font-weight:400;
  -webkit-font-smoothing:antialiased;text-rendering:optimizeLegibility;}
a{color:inherit;text-decoration:none;}
img{max-width:100%;height:auto;display:block;}
::selection{background:rgba(177,56,43,.16);}
.wrap{max-width:1140px;margin:0 auto;padding:0 26px;}
.site-main{min-height:44vh;}

/* ---- seal chop (the one place red is a fill) ---- */
.seal{display:inline-flex;align-items:center;justify-content:center;
  width:34px;height:34px;font-size:21px;line-height:1;padding-bottom:1px;flex:none;
  background:var(--cinnabar);color:var(--paper);font-family:var(--han);font-weight:500;
  border-radius:6px;box-shadow:inset 0 0 0 1.5px rgba(250,246,238,.75);}
.seal-sm{display:inline-flex;align-items:center;justify-content:center;
  width:30px;height:30px;font-size:16px;font-family:var(--han);color:var(--cinnabar);
  border:1.5px solid var(--grid-edge);border-radius:5px;background:var(--white);flex:none;}

/* ============================================================
   田字格 practice cell — the signature. White square, cinnabar
   border, faint dashed cross. Reused for hero / tones / cards.
   ============================================================ */
.cell{position:relative;background:var(--white);border:1.5px solid var(--grid-edge);
  border-radius:3px;aspect-ratio:1;display:grid;place-items:center;overflow:hidden;}
.cell .grid{position:absolute;inset:0;pointer-events:none;}
.cell .grid::before{content:"";position:absolute;top:50%;left:7%;right:7%;
  border-top:1.5px dashed var(--grid-cross);}
.cell .grid::after{content:"";position:absolute;left:50%;top:7%;bottom:7%;
  border-left:1.5px dashed var(--grid-cross);}
.cell .zi{position:relative;font-family:var(--han);font-weight:500;color:var(--ink);
  line-height:1;text-align:center;transition:color .2s;}

/* ---- top bar ---- */
.top{position:sticky;top:0;z-index:40;background:rgba(250,246,238,.86);
  -webkit-backdrop-filter:blur(8px);backdrop-filter:blur(8px);border-bottom:1px solid var(--line);}
.top .wrap{display:flex;align-items:center;justify-content:space-between;height:68px;gap:16px;}
.brand{display:flex;align-items:center;gap:12px;min-width:0;}
.brand .wm{font-family:var(--reading);font-weight:500;font-size:21px;font-style:italic;
  white-space:nowrap;overflow:hidden;text-overflow:ellipsis;}
.nav{display:flex;gap:24px;flex-wrap:wrap;justify-content:flex-end;}
.nav-item{font-family:var(--mono);font-size:12.5px;letter-spacing:.03em;color:var(--ink-soft);
  padding:6px 0;position:relative;transition:color .2s;white-space:nowrap;}
.nav-item:hover,.nav-current{color:var(--ink);}
.nav-item::after{content:"";position:absolute;left:0;right:100%;bottom:0;height:1.5px;
  background:var(--cinnabar);transition:right .22s ease;}
.nav-item:hover::after,.nav-current::after{right:0;}

/* ---- hero ---- */
.hero{padding:66px 0 34px;}
.hero .wrap{display:grid;grid-template-columns:1.15fr .85fr;gap:52px;align-items:center;}
.eyebrow{font-family:var(--mono);font-size:12px;letter-spacing:.22em;text-transform:uppercase;
  color:var(--ink-soft);margin-bottom:22px;}
.eyebrow .zh{font-family:var(--han);letter-spacing:.1em;color:var(--ink);}
.hero h1{font-family:var(--reading);font-weight:500;font-size:clamp(38px,6vw,66px);
  line-height:1.06;margin:0;color:var(--ink);letter-spacing:-.01em;}
.hero h1 em{font-style:italic;font-weight:400;}
.hero .lede{max-width:46ch;color:var(--ink-soft);margin:20px 0 0;font-size:18px;line-height:1.62;}
.hero-cta{display:flex;gap:14px;margin-top:28px;flex-wrap:wrap;}
.btn{font-family:var(--mono);font-size:12.5px;letter-spacing:.08em;text-transform:uppercase;
  padding:12px 20px;border-radius:5px;transition:transform .18s,background .2s,border-color .2s,color .2s;
  display:inline-block;}
.btn .zh{font-family:var(--han);text-transform:none;letter-spacing:.04em;margin-right:7px;}
.btn.solid{background:var(--cinnabar);color:var(--paper);}
.btn.solid:hover{transform:translateY(-2px);background:#9c3025;}
.btn.ghost{border:1.5px solid var(--ink);color:var(--ink);}
.btn.ghost:hover{background:var(--ink);color:var(--paper);}

/* hero practice field */
.herofield{display:flex;flex-direction:column;align-items:center;gap:16px;}
.hero-cell{width:min(300px,74%);}
.hero-cell .zi{font-size:clamp(120px,20vw,190px);}
.field-cap{display:flex;flex-direction:column;align-items:center;gap:2px;}
.field-cap .py{font-family:var(--mono);font-size:19px;font-weight:500;color:var(--cinnabar);letter-spacing:.04em;}
.field-cap .gl{font-family:var(--reading);font-style:italic;font-size:16px;color:var(--ink-soft);}

/* ---- tone quartet ---- */
.tones{margin-top:38px;border-top:1px solid var(--line);padding-top:22px;}
.tones .lbl{font-family:var(--mono);font-size:11px;letter-spacing:.14em;text-transform:uppercase;
  color:var(--ink-soft);margin-bottom:16px;}
.tones .lbl .zh{font-family:var(--han);letter-spacing:.06em;color:var(--ink);text-transform:none;}
.tone-set{display:flex;gap:16px;flex-wrap:wrap;}
.tone{flex:1;min-width:76px;display:flex;flex-direction:column;align-items:center;gap:8px;}
.tone-cell{width:100%;max-width:96px;}
.tone-cell .zi{font-size:clamp(34px,6vw,42px);}
.tone .py{font-family:var(--mono);font-size:14px;font-weight:500;color:var(--cinnabar);}
.tone .gl{font-size:12.5px;color:var(--ink-soft);font-style:italic;}

/* ---- divider ---- */
.divider{display:flex;align-items:center;gap:18px;max-width:1140px;margin:26px auto 0;padding:0 26px;}
.divider .ln{flex:1;height:1px;background:var(--line);}

/* ---- sections + card grid ---- */
.sec{padding:58px 0 10px;}
.sec-head{display:flex;align-items:baseline;gap:16px;margin-bottom:32px;}
.sec-head .zh{font-family:var(--han);font-weight:500;font-size:34px;color:var(--ink);}
.sec-head .en{font-family:var(--reading);font-style:italic;font-size:19px;color:var(--ink-soft);}
.sec-head .rule{flex:1;height:1px;background:var(--line);align-self:center;}
.archive-desc{color:var(--ink-soft);max-width:60ch;margin:-16px 0 24px;font-size:17px;}

.grid{display:grid;grid-template-columns:repeat(3,1fr);gap:24px;}
.card{display:flex;flex-direction:column;gap:16px;padding:16px;background:var(--paper);
  border:1px solid var(--line);border-radius:8px;transition:border-color .2s,transform .2s,box-shadow .2s;}
.card-cell{width:100%;}
.card-cell .zi{font-size:clamp(56px,9vw,78px);}
.card-cell .zi.zi-pair{font-size:clamp(38px,6vw,50px);letter-spacing:.04em;}
.card-body{display:flex;flex-direction:column;gap:9px;padding:0 4px 4px;}
.card .cat{font-family:var(--mono);font-size:11px;letter-spacing:.12em;text-transform:uppercase;color:var(--ink-soft);}
.card .cat .zh{font-family:var(--han);letter-spacing:.02em;margin-right:6px;color:var(--ink);text-transform:none;}
.card h3{font-family:var(--reading);font-weight:500;font-size:20px;line-height:1.24;margin:0;color:var(--ink);}
.card .sub{color:var(--ink-soft);font-size:14.5px;line-height:1.5;flex:1;margin:0;}
.card .meta{font-family:var(--mono);font-size:11px;color:var(--ink-faint);display:flex;gap:12px;
  padding-top:10px;border-top:1px solid var(--line);}
.card:hover{border-color:var(--grid-edge);transform:translateY(-3px);box-shadow:0 12px 28px rgba(31,26,21,.08);}
.card:hover .card-cell .zi{color:var(--cinnabar);}

/* ---- empty state ---- */
.empty{text-align:center;padding:50px 0 40px;display:flex;flex-direction:column;align-items:center;gap:18px;}
.empty-cell{width:120px;}
.empty-cell .zi{font-size:66px;}
.empty p{color:var(--ink-soft);}
.empty .zh{font-family:var(--han);color:var(--ink);}

/* ---- pagination ---- */
.pagination{display:flex;align-items:center;justify-content:center;gap:22px;margin:48px 0 10px;}
.pg-btn{font-family:var(--mono);font-size:13px;letter-spacing:.04em;padding:9px 16px;
  border:1px solid var(--line);border-radius:5px;color:var(--ink);transition:border-color .2s,color .2s;}
.pg-btn:hover{border-color:var(--cinnabar);color:var(--cinnabar);}
.pg-btn.disabled{color:var(--ink-faint);opacity:.55;pointer-events:none;}
.pg-count{font-family:var(--mono);font-size:12.5px;color:var(--ink-soft);}

/* ============================================================
   article
   ============================================================ */
.article{max-width:760px;margin:0 auto;padding:58px 0 10px;}
.kicker{font-family:var(--mono);font-size:12px;letter-spacing:.18em;text-transform:uppercase;color:var(--ink-soft);}
.kicker .zh{font-family:var(--han);letter-spacing:.02em;color:var(--ink);}
.post-title{font-family:var(--reading);font-weight:500;font-size:clamp(32px,5vw,50px);
  line-height:1.08;margin:16px 0 0;color:var(--ink);letter-spacing:-.01em;}
.post-sub{font-family:var(--reading);font-style:italic;font-size:clamp(18px,2.4vw,23px);color:var(--ink-soft);margin-top:10px;}
.byline{font-family:var(--mono);font-size:12.5px;color:var(--ink-soft);margin:18px 0 0;}
.hairline{height:1.5px;background:var(--cinnabar);width:64px;margin:22px 0 32px;border-radius:2px;}
.feature{margin:0 0 34px;}
.feature img{border-radius:8px;border:1px solid var(--line);}
.feature figcaption{font-family:var(--mono);font-size:12px;color:var(--ink-soft);text-align:center;margin-top:10px;}

/* ---- gh-content prose ---- */
.prose{max-width:66ch;margin:0 auto;font-size:18.5px;}
.gh-content > *{margin:0 0 24px;}
.gh-content p{color:var(--ink);}
.gh-content :is(h2,h3,h4){font-family:var(--reading);font-weight:600;color:var(--ink);line-height:1.24;margin:44px 0 14px;}
.gh-content h2{font-size:28px;} .gh-content h3{font-size:23px;} .gh-content h4{font-size:20px;}
.gh-content :is(h2,h3){padding-left:15px;border-left:2px solid var(--cinnabar);}
.gh-content a{color:var(--ink);box-shadow:inset 0 -1px 0 var(--cinnabar);transition:background .2s;}
.gh-content a:hover{background:rgba(177,56,43,.08);}
.gh-content :is(ul,ol){padding-left:1.3em;color:var(--ink);}
.gh-content li{margin:0 0 10px;}
.gh-content strong{color:var(--ink);font-weight:600;}
.gh-content blockquote{font-family:var(--han);font-size:22px;line-height:1.6;color:var(--ink);
  border-left:2px solid var(--cinnabar);padding:2px 0 2px 22px;margin-left:0;background:none;}
.gh-content hr{border:0;height:1px;background:var(--line);margin:44px 0;}
.gh-content img,.gh-content video{border-radius:8px;}
.gh-content figure{margin:30px 0;}
.gh-content figcaption{font-family:var(--mono);font-size:12px;color:var(--ink-soft);text-align:center;margin-top:10px;}
.gh-content :is(code,kbd){font-family:var(--mono);font-size:.85em;background:var(--paper2);
  color:var(--cinnabar);padding:2px 6px;border-radius:4px;}
.gh-content pre{background:#2A241D;color:#F3ECDF;border-radius:8px;padding:18px 20px;overflow-x:auto;
  font-family:var(--mono);font-size:14px;line-height:1.6;}
.gh-content pre code{background:none;color:inherit;padding:0;}
.gh-content .kg-callout-card{background:var(--paper2);border:1px solid var(--line);
  border-left:3px solid var(--cinnabar);border-radius:6px;padding:18px 22px;display:flex;gap:12px;}
.gh-content .kg-callout-emoji{font-size:20px;}
.gh-content .kg-bookmark-container{border:1px solid var(--line);border-radius:8px;overflow:hidden;background:var(--white);}
.gh-content .kg-bookmark-title{color:var(--ink);} .gh-content .kg-bookmark-description{color:var(--ink-soft);}
.gh-content .kg-bookmark-card a{box-shadow:none;background:none;}
.gh-content .kg-width-wide{margin-left:calc(50% - 50vw);margin-right:calc(50% - 50vw);width:100vw;max-width:100vw;}
.gh-content .kg-width-wide img{max-width:1000px;margin:0 auto;}
.gh-content .kg-width-full{margin-left:calc(50% - 50vw);margin-right:calc(50% - 50vw);width:100vw;max-width:100vw;}
.gh-content .kg-width-full img{width:100%;border-radius:0;}

.post-tags{max-width:66ch;margin:44px auto 0;display:flex;gap:10px;flex-wrap:wrap;}
.tag-chip{font-family:var(--mono);font-size:12px;letter-spacing:.04em;padding:6px 12px;
  border:1px solid var(--line);border-radius:100px;color:var(--ink-soft);transition:border-color .2s,color .2s;}
.tag-chip:hover{border-color:var(--cinnabar);color:var(--cinnabar);}
.comments-wrap{max-width:760px;margin:0 auto;padding:40px 0;}

/* ---- error ---- */
.errsec{text-align:center;padding:96px 0;display:flex;flex-direction:column;align-items:center;}
.err-cell{width:120px;margin-bottom:26px;}
.err-cell .zi{font-size:66px;}
.err-code{font-family:var(--mono);font-size:15px;letter-spacing:.2em;color:var(--ink-soft);}
.err-msg{color:var(--ink);font-family:var(--reading);font-size:22px;margin:6px 0 0;}
.err-sub{color:var(--ink-soft);margin:8px 0 30px;}
.err-sub .zh{font-family:var(--han);color:var(--ink);}

/* ---- footer ---- */
.foot{margin-top:80px;border-top:1px solid var(--line);}
.foot .wrap{padding:44px 26px;display:flex;align-items:center;justify-content:space-between;gap:22px;flex-wrap:wrap;}
.foot .left{display:flex;align-items:center;gap:14px;}
.foot .wm{font-family:var(--reading);font-style:italic;font-weight:500;font-size:19px;color:var(--ink);}
.foot .fx{font-family:var(--mono);font-size:12px;color:var(--ink-soft);line-height:1.9;text-align:right;}
.foot .fx .zh{font-family:var(--han);color:var(--ink);}

/* ---- responsive ---- */
@media (max-width:900px){
  .hero{padding:44px 0 20px;}
  .hero .wrap{grid-template-columns:1fr;gap:34px;}
  .herofield{order:-1;}
  .grid{grid-template-columns:1fr 1fr;}
  .top .wrap{height:auto;padding:12px 0;flex-wrap:wrap;}
  .nav{gap:16px;}
  .foot .fx{text-align:left;}
}
@media (max-width:560px){
  .grid{grid-template-columns:1fr;}
  .tone{min-width:64px;}
}
@media (prefers-reduced-motion:reduce){
  html{scroll-behavior:auto;}
  .card,.btn,.nav-item::after{transition:none;}
}

/* ============================================================
   Reading widgets — inline ruby vocab, vocab lists, practice
   sentences, callouts. Behaviour lives in assets/js/reader.js.
   All light-theme: ink on paper, cinnabar reserved for the grid.
   ============================================================ */

/* inline ruby vocab word — tap to reveal pinyin/meaning */
.gh-content ruby.z{position:relative;ruby-position:over;font-family:var(--han);color:var(--ink);cursor:pointer;
  border-bottom:1px dotted var(--ink-faint);transition:border-color .15s;}
.gh-content ruby.z:hover,.gh-content ruby.z:focus{border-bottom-color:var(--cinnabar);outline:none;}
.gh-content ruby.z rt{font-family:var(--mono);font-size:13px;font-weight:500;color:var(--cinnabar);visibility:hidden;}
.gh-content ruby.z.revealed rt,body.reveal-all .gh-content ruby.z rt{visibility:visible;}
.gh-content ruby.z.revealed[data-en]::after{content:attr(data-en);position:absolute;left:50%;top:100%;
  transform:translateX(-50%);margin-top:.35rem;white-space:nowrap;z-index:5;font-family:var(--reading);
  font-size:12px;color:var(--paper);background:var(--ink);padding:.22rem .55rem;border-radius:5px;pointer-events:none;}

/* vocab list — tap a row to reveal pinyin + gloss */
.gh-content .vocab{margin:1.8rem 0;border-top:1px solid var(--line);}
.gh-content .vocab-row{display:grid;grid-template-columns:84px 1fr;align-items:center;gap:0 1rem;
  padding:.6rem .4rem;border-bottom:1px solid var(--line);cursor:pointer;transition:background .15s;}
.gh-content .vocab-row:hover,.gh-content .vocab-row:focus{background:var(--paper2);outline:none;}
.gh-content .vocab-hz{grid-row:1/span 2;font-family:var(--han);font-size:30px;line-height:1.1;color:var(--ink);white-space:nowrap;}
.gh-content .vocab-py,.gh-content .vocab-en{max-height:0;opacity:0;overflow:hidden;transition:max-height .18s ease,opacity .18s ease;}
.gh-content .vocab-py{font-family:var(--mono);font-size:15px;font-weight:500;color:var(--cinnabar);}
.gh-content .vocab-en{font-size:16px;color:var(--ink-soft);}
.gh-content .vocab-row.revealed .vocab-py,body.reveal-all .gh-content .vocab-row .vocab-py{max-height:2rem;opacity:1;margin-top:.15rem;}
.gh-content .vocab-row.revealed .vocab-en,body.reveal-all .gh-content .vocab-row .vocab-en{max-height:2.5rem;opacity:1;margin-bottom:.15rem;}

/* practice sentence on a 田字格 writing grid */
.gh-content .sentence{margin:2rem 0;padding:2rem 1.2rem 1.6rem;text-align:center;background:var(--white);
  border:1.5px solid var(--grid-edge);border-radius:6px;cursor:pointer;position:relative;overflow:hidden;}
.gh-content .sentence::before{content:"";position:absolute;inset:0;pointer-events:none;
  background-image:linear-gradient(var(--grid-cross) 1px,transparent 1px),linear-gradient(90deg,var(--grid-cross) 1px,transparent 1px);
  background-size:2.4rem 2.4rem;background-position:center;
  -webkit-mask-image:radial-gradient(ellipse at center,#000 55%,transparent 92%);mask-image:radial-gradient(ellipse at center,#000 55%,transparent 92%);}
.gh-content .sentence > *{position:relative;}
.gh-content .sentence:hover,.gh-content .sentence:focus{border-color:var(--cinnabar);outline:none;}
.gh-content .sentence-hz{font-family:var(--han);font-size:38px;letter-spacing:.12em;color:var(--ink);line-height:1.3;}
.gh-content .sentence-py{font-family:var(--mono);font-size:16px;font-weight:500;color:var(--cinnabar);margin-top:.6rem;visibility:hidden;}
.gh-content .sentence-en{font-size:16px;color:var(--ink-soft);margin-top:.15rem;visibility:hidden;}
.gh-content .sentence-hint{position:absolute;top:.6rem;right:.9rem;font-family:var(--mono);font-size:0;font-weight:500;
  letter-spacing:.06em;text-transform:uppercase;color:var(--ink-soft);opacity:.9;}
.gh-content .sentence-hint::after{content:"Show";font-size:13px;}
.gh-content .sentence.revealed .sentence-py,body.reveal-all .gh-content .sentence .sentence-py,
.gh-content .sentence.revealed .sentence-en,body.reveal-all .gh-content .sentence .sentence-en{visibility:visible;}
.gh-content .sentence.revealed .sentence-hint,body.reveal-all .gh-content .sentence .sentence-hint{display:none;}

/* callout — paper panel with a cinnabar spine */
.gh-content .callout{background:var(--paper2);border:1px solid var(--line);border-left:3px solid var(--cinnabar);
  padding:1rem 1.2rem;border-radius:0 6px 6px 0;margin:2rem 0;font-size:16px;color:var(--ink);}
.gh-content .callout :is(p,li,strong,em,b){color:var(--ink);}
.gh-content .callout p:first-child{margin-top:0;}
.gh-content .callout p:last-child{margin-bottom:0;}

/* floating "show pinyin" toggle (built by JS when a lesson has vocab) */
#reveal-all{position:fixed;right:18px;bottom:18px;z-index:50;font-family:var(--mono);font-size:14px;font-weight:500;
  cursor:pointer;color:var(--paper);background:var(--ink);border:none;padding:10px 18px;border-radius:999px;
  box-shadow:0 4px 16px rgba(31,26,21,.22);}
#reveal-all[aria-pressed="true"]{background:var(--cinnabar);}