/* ============================================================
   nano4M-Audio — project site
   Light theme · serif headings · sans body · modest blue accent
   Self-hosted system font stacks (no CDN). To use Crimson Pro /
   Inter webfonts, drop WOFF2 files in assets/fonts/ and add
   @font-face here, then update --serif / --sans.
   ============================================================ */

:root{
  --bg:#FAFAF8;
  --ink:#1A1A1A;
  --body:#262626;
  --gray:#666;
  --soft:#6f6f68;
  --accent:#0066CC;
  --accent-dk:#0b3a6b;
  --accent-bg:#eef4fc;
  --card:#FFFFFF;
  --border:#E3E3DC;
  --border-soft:#ececE4;
  --warn-bg:#fff8e6;
  --warn-bd:#f0e2b8;
  --warn-ink:#6b5900;
  --serif:'Crimson Pro','Lora',Georgia,'Iowan Old Style','Times New Roman',serif;
  --sans:'Inter',-apple-system,BlinkMacSystemFont,'Segoe UI',Roboto,Helvetica,Arial,sans-serif;
  --mono:'JetBrains Mono',ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;
  --sidebar-w:250px;
  --maxw:900px;
}

*{box-sizing:border-box}
html{scroll-behavior:smooth;overflow-x:clip}
body{
  margin:0;
  background:var(--bg);
  color:var(--body);
  font-family:var(--sans);
  font-size:17px;
  line-height:1.7;
  -webkit-font-smoothing:antialiased;
  text-rendering:optimizeLegibility;
}
img{max-width:100%;height:auto;display:block}
a{color:var(--accent);text-decoration:none}
a:hover{text-decoration:underline}
code{font-family:var(--mono);font-size:.88em;background:#f1f1ea;padding:.08em .35em;border-radius:4px}

h1,h2,h3,h4{font-family:var(--serif);color:var(--ink);line-height:1.18;font-weight:600}
h2{font-size:clamp(1.7rem,3.4vw,2.25rem);margin:0 0 .6em}
h3{font-size:1.34rem;margin:1.8em 0 .5em}
h4{font-family:var(--sans);font-size:.78rem;letter-spacing:.08em;text-transform:uppercase;color:var(--soft);margin:0 0 .8em}
p{margin:0 0 1em}

.skip-link{position:absolute;left:-9999px;top:0;background:var(--accent);color:#fff;padding:10px 16px;border-radius:0 0 8px 0;z-index:100}
.skip-link:focus{left:0}
:focus-visible{outline:2.5px solid var(--accent);outline-offset:2px;border-radius:3px}

/* ---------- mobile top bar ---------- */
.topbar{
  display:none;
  position:sticky;top:0;z-index:40;
  align-items:center;justify-content:space-between;
  padding:10px 16px;background:rgba(250,250,248,.94);
  -webkit-backdrop-filter:saturate(140%) blur(6px);
  backdrop-filter:saturate(140%) blur(6px);
  border-bottom:1px solid var(--border);
}
.topbar-brand{font-family:var(--serif);font-size:1.15rem;font-weight:600;color:var(--ink);display:flex;align-items:center;gap:8px}
.topbar-logo{width:26px;height:26px}
.topbar-brand:hover{text-decoration:none}
.nav-toggle{
  font-size:1.4rem;line-height:1;background:none;border:1px solid var(--border);
  border-radius:8px;padding:4px 12px;cursor:pointer;color:var(--ink);
}

/* ---------- sidebar ---------- */
.sidebar{
  position:fixed;top:0;left:0;width:var(--sidebar-w);height:100vh;height:100dvh;
  padding:34px 24px;border-right:1px solid var(--border);
  background:var(--bg);overflow-y:auto;z-index:50;
}
.brand{font-family:var(--serif);font-size:1.2rem;font-weight:600;color:var(--ink);display:flex;align-items:center;gap:8px;line-height:1.1}
.brand-logo{width:30px;height:30px;flex:none}
.brand:hover{text-decoration:none}
.brand-sub{font-size:.8rem;color:var(--soft);margin:.2em 0 1.6em}
.nav-list{list-style:none;margin:0;padding:0}
.nav-list li{margin:0}
.nav-list a{
  display:block;padding:6px 12px;margin:1px 0;
  color:var(--gray);font-size:.93rem;border-left:2px solid transparent;
}
.nav-list a:hover{color:var(--ink);text-decoration:none}
.nav-list a.active{color:var(--ink);border-left-color:#1a1a1a;font-weight:600}
.nav-foot{margin-top:24px;padding-top:16px;border-top:1px solid var(--border);font-size:.74rem;color:var(--soft)}

/* ---------- main ---------- */
#main{margin-left:var(--sidebar-w)}
section{scroll-margin-top:24px}
#top{scroll-margin-top:0}

/* ---------- hero ---------- */
.hero{
  display:flex;flex-direction:column;align-items:center;justify-content:center;
  text-align:center;padding:52px 24px 48px;
}
.hero-logo{width:104px;height:104px;display:block;margin:0 auto 20px}
.venue{font-size:.8rem;letter-spacing:.02em;color:var(--gray);margin:0 0 16px;font-weight:500}
.hero h1{font-size:clamp(1.85rem,3.7vw,2.75rem);max-width:24ch;margin:0 0 .4em;text-wrap:balance}
.subtitle{font-size:clamp(1.05rem,2vw,1.3rem);color:var(--gray);max-width:42ch;margin:0 0 1.4em}
.authors{font-size:1rem;color:var(--ink);margin:0 0 2em;max-width:60ch}
.authors-sup{color:var(--gray)}

.btn-row{display:flex;flex-wrap:wrap;gap:12px;justify-content:center;margin-bottom:48px}
.btn{
  display:inline-flex;align-items:center;gap:8px;padding:10px 18px;
  background:var(--card);border:1px solid var(--border);border-radius:9px;
  color:var(--ink);font-size:.95rem;font-weight:500;transition:border-color .15s,color .15s,background .15s;
}
.btn:hover{border-color:var(--accent);color:var(--accent);text-decoration:none}
.btn-ico{flex:none;display:block}
.btn-accent{background:var(--accent);border-color:var(--accent);color:#fff}
.btn-accent:hover{background:var(--accent-dk);border-color:var(--accent-dk);color:#fff}

.pull-figure{margin:0;max-width:840px;width:100%}
.pull-figure img{width:100%;border:1px solid var(--border);border-radius:12px;background:#fff;padding:12px}
figcaption{font-size:.88rem;color:var(--gray);line-height:1.55;margin-top:12px;text-align:left}
.pull-figure figcaption{text-align:center;max-width:64ch;margin-inline:auto}

/* ---------- prose sections ---------- */
.prose{max-width:var(--maxw);margin:0 auto;padding:74px 24px;border-top:1px solid var(--border-soft)}
.prose.narrow{max-width:760px}
.lead-italic{font-style:italic;color:#3d3d3d;font-size:1.08rem;line-height:1.65}
p.lead-italic{border-left:3px solid var(--border);padding-left:18px;margin-bottom:1.4em}

/* two-column */
.two-col{display:grid;grid-template-columns:minmax(0,1.55fr) minmax(220px,1fr);gap:34px;align-items:start}
.col-fig{margin:0}
.col-fig img{width:100%;border:1px solid var(--border);border-radius:10px;background:#fff;padding:10px}

/* figures */
figure.wide{margin:26px 0}
figure.wide img{width:100%;border:1px solid var(--border);border-radius:10px;background:#fff;padding:10px}
figure.wide img.full{padding:0;background:transparent}
figure.chart-fig{margin:26px auto;max-width:560px}
figure.chart-fig img{width:100%;border:1px solid var(--border);border-radius:10px;background:#fff;padding:10px}
.fig-cap{font-size:.88rem;color:var(--gray);line-height:1.55;margin-top:6px}

/* tables */
.table-wrap{overflow-x:auto;margin:20px 0}
table{border-collapse:collapse;width:100%;font-size:.95rem}
caption{caption-side:top;text-align:left;font-size:.85rem;color:var(--gray);margin-bottom:8px}
th,td{padding:10px 14px;border-bottom:1px solid var(--border);text-align:left;vertical-align:top}
thead th{background:#f3f3ee;font-family:var(--sans);font-weight:600;color:var(--ink);border-bottom:2px solid var(--border)}
.data-table td code{background:#f1f1ea}
.num{text-align:right;font-family:var(--mono);font-size:.9rem;white-space:nowrap}

/* stats box */
.stats-box{background:var(--card);border:1px solid var(--border);border-radius:12px;padding:20px 22px}
.stats-box ul{list-style:none;margin:0;padding:0}
.stats-box li{display:flex;align-items:baseline;gap:8px;padding:5px 0;border-bottom:1px solid var(--border-soft);font-size:.9rem;color:var(--gray)}
.stats-box li:last-child{border-bottom:0}
.stats-box li span{font-family:var(--mono);font-weight:700;color:var(--accent);font-size:1rem;min-width:64px}

/* callout */
.callout{background:var(--accent-bg);border-left:4px solid var(--accent);border-radius:8px;padding:16px 22px;margin:24px 0}
.callout p{margin:0}

/* cards */
.cards{display:grid;grid-template-columns:repeat(auto-fit,minmax(240px,1fr));gap:20px;margin:24px 0}
.card{background:var(--card);border:1px solid var(--border);border-radius:12px;padding:22px 24px}
.card h3{margin:0 0 .5em;font-size:1.18rem}
.card p{font-size:.94rem;line-height:1.62;margin:0 0 .8em}
.card .lever{margin:14px 0 0;padding-top:12px;border-top:1px dashed var(--border);font-size:.9rem;color:#444}

/* team */
.authors-list{display:grid;grid-template-columns:repeat(3,1fr);gap:30px;margin:6px 0 4px}
.author h3{margin:0 0 .35em;font-size:1.12rem}
.author .role{font-size:.9rem;color:var(--gray);line-height:1.6;margin:0 0 .5em}
.author .meta{font-family:var(--mono);font-size:.76rem;color:var(--soft);margin:0}
.author .meta a{font-family:var(--sans)}
@media (max-width:760px){.authors-list{grid-template-columns:1fr;gap:22px}}

/* acknowledgements + bibtex */
.ack{margin-top:36px}
.cite-h{margin-top:34px;margin-bottom:.45em}
.bibtex-block{position:relative;margin-top:4px}
.copy-btn{position:absolute;top:12px;right:14px;font-family:var(--sans);font-size:.74rem;color:var(--gray);
  background:transparent;border:0;border-bottom:1px dashed var(--soft);padding:1px 0;cursor:pointer}
.copy-btn:hover{color:var(--ink);border-bottom-color:var(--ink)}
.copy-btn.copied{color:#1a7a3c;border-bottom-color:#1a7a3c}
.bibtex-block pre{background:#f5f5f0;border:1px solid var(--border-soft);border-radius:8px;padding:16px;overflow-x:auto;margin:0}
.bibtex-block code{background:none;padding:0;font-size:.84rem;line-height:1.5;color:#2a2a2a}

/* audio demo */
.audio-demo .cls{font-weight:600;font-family:var(--serif);font-size:1.05rem;white-space:nowrap}
.audio-demo audio{width:100%;min-width:140px;max-width:220px;height:38px}
.audio-demo td:last-child{font-size:.86rem;color:var(--gray);min-width:150px}
.audio-demo .th-sub{display:block;font-weight:400;font-size:.74rem;color:var(--gray);letter-spacing:.2px;margin-top:2px}
.note-inline{background:var(--warn-bg);border:1px solid var(--warn-bd);border-radius:8px;
  padding:12px 16px;font-size:.9rem;color:var(--warn-ink);line-height:1.55}
.note-inline code{background:#fff2cf}

/* fill-in marker */
.todo{background:#fff2cf;border-bottom:1.5px dashed #d8b14a;padding:0 3px;border-radius:2px;font-weight:600;color:#7a5f0a;cursor:help}

/* footer */
.site-footer{max-width:var(--maxw);margin:0 auto;padding:48px 24px 72px;border-top:1px solid var(--border-soft);
  text-align:center;color:var(--gray);font-size:.85rem;line-height:1.6}
.site-footer .muted{color:var(--soft)}

/* ============================================================
   responsive
   ============================================================ */
@media (max-width:999px){
  .topbar{display:flex}
  #main{margin-left:0}
  .sidebar{
    transform:translateX(-100%);
    visibility:hidden;
    transition:transform .22s ease, visibility .22s ease;
    box-shadow:2px 0 18px rgba(0,0,0,.12);
    width:min(82vw,300px);
  }
  .sidebar.open{transform:translateX(0);visibility:visible}
  section{scroll-margin-top:64px}
  .hero{min-height:auto;padding:48px 20px 40px}
}
@media (min-width:1000px){
  .topbar{display:none}
}
@media (max-width:760px){
  body{font-size:16px}
  .two-col{grid-template-columns:1fr;gap:22px}
  .prose{padding:54px 20px}
  .btn{flex:0 1 auto;justify-content:center}
}

@media (prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  .sidebar{transition:none}
}

/* ---------- real-example block (data journey) ---------- */
.ex-video{display:block;width:100%;max-width:460px;margin:0 auto;border:1px solid var(--border);border-radius:10px;background:#000}
.ex-vidcap{font-size:.82rem;color:var(--gray);text-align:center;margin:10px auto 20px;max-width:560px}
.ex-vidcap code{font-size:.82em}
.example-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:12px;max-width:600px;margin:0 auto}
.ex-tile{background:var(--card);border:1px solid var(--border);border-radius:10px;padding:8px;text-align:center;display:flex;flex-direction:column}
.ex-tile img{width:100%;border-radius:6px;display:block;aspect-ratio:4/3;object-fit:cover}
.ex-tile .lbl{font-weight:600;font-size:.82rem;margin-top:8px;color:var(--ink)}
.ex-tile .lbl span{display:block;font-weight:400;font-size:.7rem;color:var(--soft)}
.ex-tile.ex-audio audio{width:100%;margin:auto 0}
.ex-tile.ex-cap{justify-content:center}
.ex-quote{font-family:var(--serif);font-style:italic;color:#7a6300;font-size:1.02rem;padding:12px 4px;flex:1;display:flex;align-items:center;justify-content:center}
@media (max-width:620px){.example-grid{grid-template-columns:repeat(2,1fr)}}