/* heyi.ai — black & white theme */
:root{
  --bg:#ffffff;
  --fg:#0a0a0a;
  --muted:#6b6b6b;
  --line:#e6e6e6;
  --card:#ffffff;
  --soft:#f5f5f5;
  --inv-bg:#0a0a0a;
  --inv-fg:#ffffff;
  --radius:14px;
  --side-w:248px;
}
@media (prefers-color-scheme:dark){
  :root:not([data-theme="light"]){
    --bg:#000000;--fg:#f5f5f5;--muted:#9a9a9a;--line:#222222;--card:#0b0b0b;--soft:#141414;--inv-bg:#ffffff;--inv-fg:#000000;
  }
}
:root[data-theme="dark"]{
  --bg:#000000;--fg:#f5f5f5;--muted:#9a9a9a;--line:#222222;--card:#0b0b0b;--soft:#141414;--inv-bg:#ffffff;--inv-fg:#000000;
}

*{box-sizing:border-box}
html{-webkit-text-size-adjust:100%}
body{margin:0;background:var(--bg);color:var(--fg);font:15px/1.6 Inter,system-ui,-apple-system,Segoe UI,Roboto,sans-serif}
a{color:inherit;text-underline-offset:3px}
img{max-width:100%;display:block}
h1,h2,h3{line-height:1.15;margin:0 0 .5em;letter-spacing:-.02em;font-weight:600}
h1{font-size:clamp(32px,5vw,52px)}
h2{font-size:24px}
h3{font-size:16px}
p{margin:0 0 1em}

/* shell */
.shell{display:flex;min-height:100vh}
.side{position:sticky;top:0;height:100vh;width:var(--side-w);flex:none;border-right:1px solid var(--line);padding:20px 14px;display:flex;flex-direction:column;gap:4px;background:var(--bg)}
.main{flex:1;min-width:0}
.page{max-width:1040px;margin:0 auto;padding:40px 32px 32px}

.brand{display:flex;align-items:center;gap:10px;padding:6px 10px 18px;text-decoration:none;font-weight:600;font-size:17px;letter-spacing:-.01em}
.brand img{width:32px;height:32px;border-radius:8px}
.brand .tld{color:var(--muted);font-weight:500}
.nav a{display:flex;align-items:center;gap:10px;padding:8px 10px;border-radius:9px;text-decoration:none;color:var(--muted);font-weight:500}
.nav a:hover{background:var(--soft);color:var(--fg)}
.nav a.active{background:var(--inv-bg);color:var(--inv-fg)}
.nav svg{width:16px;height:16px;flex:none}
.side-foot{margin-top:auto;padding:10px;font-size:12px;color:var(--muted);display:flex;flex-direction:column;gap:10px}
.theme-btn{all:unset;cursor:pointer;font-size:12px;border:1px solid var(--line);border-radius:999px;padding:4px 10px;align-self:flex-start}
.theme-btn:hover{border-color:var(--fg)}

.topbar{display:none}
.menu-btn{all:unset;cursor:pointer;padding:6px;border-radius:8px}
.menu-btn svg{width:22px;height:22px;display:block}
.scrim{display:none}

/* type helpers */
.eyebrow{font-size:12px;text-transform:uppercase;letter-spacing:.12em;color:var(--muted);font-weight:600;margin-bottom:10px}
.lead{font-size:18px;color:var(--muted);max-width:620px}
.muted{color:var(--muted)}
.small{font-size:13px}
.mono{font-family:ui-monospace,SFMono-Regular,Menlo,monospace}

/* hero */
.hero{display:grid;grid-template-columns:1.1fr 1fr;gap:40px;align-items:center;margin-bottom:48px}
.hero-img{border-radius:var(--radius);overflow:hidden;border:1px solid var(--line);aspect-ratio:1/1;background:var(--soft)}
.hero-img img{width:100%;height:100%;object-fit:cover}
.hero-tag{font-size:12px;color:var(--muted);margin-top:8px}
.actions{display:flex;flex-wrap:wrap;gap:10px;margin-top:22px}
.ticker{display:inline-flex;align-items:center;gap:8px;border:1px solid var(--line);border-radius:999px;padding:4px 12px 4px 6px;font-size:13px;margin-bottom:18px}
.ticker .dot{width:8px;height:8px;border-radius:50%;background:var(--fg);animation:pulse 1.6s infinite}
@keyframes pulse{50%{opacity:.25}}

/* buttons */
.btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;padding:10px 18px;border-radius:999px;background:var(--inv-bg);color:var(--inv-fg);text-decoration:none;font-weight:500;border:1px solid var(--inv-bg);cursor:pointer;font:inherit;font-weight:500}
.btn:hover{opacity:.85}
.btn.ghost{background:transparent;color:var(--fg);border-color:var(--line)}
.btn.ghost:hover{border-color:var(--fg);opacity:1}
.btn:disabled,.btn[disabled]{opacity:.4;cursor:not-allowed}

/* layout */
.block{margin:0 0 40px}
.grid{display:grid;gap:16px;margin-bottom:40px}
.g2{grid-template-columns:repeat(2,minmax(0,1fr))}
.g3{grid-template-columns:repeat(3,minmax(0,1fr))}
.g4{grid-template-columns:repeat(4,minmax(0,1fr))}
.card{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:20px}
.card.inv{background:var(--inv-bg);color:var(--inv-fg);border-color:var(--inv-bg)}
.card.inv .muted{color:inherit;opacity:.7}
.card h3{margin-bottom:6px}
.card .num{font-size:12px;color:var(--muted);font-weight:600;margin-bottom:14px;display:block}

.stat{display:flex;flex-direction:column;gap:4px}
.stat .l{font-size:12px;color:var(--muted);text-transform:uppercase;letter-spacing:.08em}
.stat .n{font-size:32px;font-weight:600;letter-spacing:-.02em}

.kv{display:flex;justify-content:space-between;gap:16px;padding:10px 0;border-bottom:1px solid var(--line);font-size:14px}
.kv:last-child{border-bottom:0}
.kv span{color:var(--muted)}
.kv b{font-weight:500;text-align:right}

/* forms */
label{display:grid;gap:6px;font-size:13px;color:var(--muted);font-weight:500}
input,select{font:inherit;color:var(--fg);background:var(--soft);border:1px solid var(--line);border-radius:10px;padding:10px 12px;width:100%}
input:disabled,select:disabled{opacity:.6}

/* table */
.table-wrap{overflow-x:auto}
table{width:100%;border-collapse:collapse;font-size:14px}
th,td{text-align:left;padding:10px 8px;border-bottom:1px solid var(--line);white-space:nowrap}
th{font-size:12px;color:var(--muted);font-weight:600;text-transform:uppercase;letter-spacing:.06em}
tr:last-child td{border-bottom:0}
.empty-row td{text-align:center;color:var(--muted);padding:32px 8px}

/* search */
.search{display:flex;gap:8px;margin-bottom:24px}
.search input{flex:1}

/* docs */
.docs{display:grid;grid-template-columns:200px minmax(0,1fr);gap:40px;align-items:start;margin-bottom:40px}
.toc{position:sticky;top:24px;display:flex;flex-direction:column;gap:2px;border-left:1px solid var(--line)}
.toc a{padding:5px 14px;text-decoration:none;color:var(--muted);font-size:14px;margin-left:-1px;border-left:2px solid transparent}
.toc a:hover{color:var(--fg)}
.toc a.active{color:var(--fg);border-left-color:var(--fg);font-weight:500}
article section{padding-bottom:28px;margin-bottom:28px;border-bottom:1px solid var(--line);scroll-margin-top:24px}
article section:last-child{border-bottom:0}
article ul{padding-left:20px;margin:0 0 1em}
pre,code{font-family:ui-monospace,SFMono-Regular,Menlo,monospace;font-size:13px}
pre{background:var(--soft);border:1px solid var(--line);border-radius:10px;padding:14px;overflow-x:auto}
details{border:1px solid var(--line);border-radius:10px;padding:12px 16px;margin-bottom:8px}
summary{cursor:pointer;font-weight:500}
details p{margin:10px 0 0;color:var(--muted)}

/* feed */
.seg{display:inline-flex;flex-wrap:wrap;gap:4px;border:1px solid var(--line);border-radius:999px;padding:4px;margin-bottom:24px}
.seg button{all:unset;cursor:pointer;padding:6px 14px;border-radius:999px;font-size:14px;color:var(--muted)}
.seg button.active{background:var(--inv-bg);color:var(--inv-fg)}
.post{border:1px solid var(--line);border-radius:var(--radius);padding:20px;margin-bottom:12px}
.post-meta{display:flex;align-items:center;gap:8px;font-size:13px;color:var(--muted);margin-bottom:10px;flex-wrap:wrap}
.post-meta img{width:24px;height:24px;border-radius:50%;object-fit:cover}
.post-meta b{color:var(--fg);font-weight:600}
.post p{color:var(--muted)}
.post a{font-size:14px;font-weight:500}
.badge{font-size:11px;font-weight:600;padding:2px 8px;border-radius:999px;background:var(--inv-bg);color:var(--inv-fg)}
.badge.gray{background:var(--soft);color:var(--muted);border:1px solid var(--line)}

/* footer */
.foot{border-top:1px solid var(--line);padding-top:20px;margin-top:20px;font-size:12px;color:var(--muted)}

/* responsive */
@media (max-width:900px){
  .hero{grid-template-columns:1fr;gap:28px}
  .hero-img{order:-1;max-width:420px}
  .g3,.g4{grid-template-columns:repeat(2,minmax(0,1fr))}
  .docs{grid-template-columns:1fr}
  .toc{position:static;flex-direction:row;flex-wrap:wrap;border-left:0;gap:6px}
  .toc a{border:1px solid var(--line);border-radius:999px;margin:0;padding:4px 12px}
  .toc a.active{border-color:var(--fg)}
}
@media (max-width:760px){
  .shell{display:block}
  .topbar{display:flex;align-items:center;justify-content:space-between;padding:12px 16px;border-bottom:1px solid var(--line);position:sticky;top:0;background:var(--bg);z-index:20}
  .topbar .brand{padding:0}
  .side{position:fixed;left:0;top:0;z-index:40;transform:translateX(-100%);transition:transform .2s ease;box-shadow:none}
  body.nav-open .side{transform:none}
  body.nav-open .scrim{display:block;position:fixed;inset:0;background:rgba(0,0,0,.4);z-index:30}
  .page{padding:28px 16px 24px}
  .g2{grid-template-columns:1fr}
}
@media (max-width:480px){
  .g3,.g4{grid-template-columns:1fr}
}