*,*::before,*::after{box-sizing:border-box;margin:0;padding:0}
:root{
  --bg:#f5f3ef;--surface:#fff;--border:#e5e0d8;
  --text:#1c1917;--muted:#78716c;--radius:12px;
  --code-bg:#18181b;--lang:#1c1917;
  font-size:16px;
}
body{font-family:'Syne',sans-serif;background:var(--bg);color:var(--text);min-height:100vh;overflow-x:hidden}
::-webkit-scrollbar{width:5px;height:5px}
::-webkit-scrollbar-track{background:transparent}
::-webkit-scrollbar-thumb{background:var(--border);border-radius:99px
}


/* ── HOME ── */
#home{min-height:100vh;display:flex;flex-direction:column;align-items:center;justify-content:center;padding:2rem;gap:0}
.home-eyebrow{font-family:'JetBrains Mono',monospace;font-size:.7rem;letter-spacing:.14em;text-transform:uppercase;color:var(--muted);margin-bottom:1.25rem;opacity:0;animation:fadeUp .5s .1s ease forwards}
.home-h1{font-size:clamp(2.2rem,6vw,4rem);font-weight:700;letter-spacing:-.04em;line-height:1.1;text-align:center;margin-bottom:.5rem;opacity:0;animation:fadeUp .5s .2s ease forwards}
.home-h1 em{font-style:italic;font-weight:400}
.home-sub{color:var(--muted);font-size:.95rem;margin-bottom:3.5rem;font-weight:400;opacity:0;animation:fadeUp .5s .3s ease forwards}
.lang-grid{display:grid;grid-template-columns:repeat(5,1fr);gap:.875rem;width:100%;max-width:860px}
.lang-card{
  background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);
  padding:1.75rem 1.25rem 1.5rem;cursor:pointer;text-align:left;position:relative;overflow:hidden;
  transition:transform .22s ease,box-shadow .22s ease,border-color .22s ease;
  opacity:0;animation:fadeUp .45s ease forwards;
}
.lang-card:nth-child(1){animation-delay:.15s}.lang-card:nth-child(2){animation-delay:.2s}
.lang-card:nth-child(3){animation-delay:.25s}.lang-card:nth-child(4){animation-delay:.3s}
.lang-card:nth-child(5){animation-delay:.35s}
.lang-card::after{
  content:'';position:absolute;bottom:0;left:0;right:0;height:2px;
  background:var(--lang);transform:scaleX(0);transition:transform .22s ease;transform-origin:left
}
.lang-card:hover{transform:translateY(-5px);box-shadow:0 16px 40px rgba(0,0,0,.09);border-color:transparent}
.lang-card:hover::after{transform:scaleX(1)}
.lc-tag{
  font-family:'JetBrains Mono',monospace;font-size:.68rem;font-weight:500;
  background:color-mix(in srgb,var(--lang) 12%,transparent);
  color:var(--lang);padding:.2rem .5rem;border-radius:4px;
  display:inline-block;margin-bottom:1.1rem
}
.lc-name{font-size:1.05rem;font-weight:600;margin-bottom:.2rem;letter-spacing:-.01em}
.lc-desc{font-size:.75rem;color:var(--muted);line-height:1.5;font-weight:400}
.lc-arrow{
  position:absolute;bottom:1.25rem;right:1.25rem;
  font-size:.9rem;color:var(--border);transition:color .2s,transform .2s
}
.lang-card:hover .lc-arrow{color:var(--lang);transform:translate(2px,-2px)}

/* ── DETAIL ── */
#detail{display:none;min-height:100vh;flex-direction:column}
#detail.active{display:flex;animation:fadeIn .35s ease}
.det-header{
  position:sticky;top:0;z-index:100;
  background:rgba(245,243,239,.93);backdrop-filter:blur(16px);
  border-bottom:1px solid var(--border);padding:.9rem 1.75rem;
  display:flex;align-items:center;gap:1rem
}
.back-btn{
  display:flex;align-items:center;gap:.5rem;
  background:none;border:1px solid var(--border);border-radius:8px;
  padding:.45rem .9rem;cursor:pointer;font-family:'Syne',sans-serif;
  font-size:.8rem;color:var(--muted);transition:all .18s
}
.back-btn:hover{color:var(--text);border-color:var(--text)}
.det-lang-info{display:flex;align-items:center;gap:.65rem;margin-left:.25rem}
.det-dot{width:8px;height:8px;border-radius:50%;background:var(--lang);flex-shrink:0}
.det-name{font-size:.95rem;font-weight:600;letter-spacing:-.01em}
.det-body{display:grid;grid-template-columns:220px 1fr;flex:1;overflow:hidden}

/* ── SIDEBAR ── */
.sidebar{border-right:1px solid var(--border);padding:1.5rem .875rem;position:sticky;top:57px;height:calc(100vh - 57px);overflow-y:auto}
.sb-label{
  font-family:'JetBrains Mono',monospace;font-size:.62rem;letter-spacing:.1em;
  text-transform:uppercase;color:var(--muted);margin-bottom:.5rem;padding:0 .5rem;display:block
}
.sb-item{
  display:flex;align-items:center;gap:.5rem;
  padding:.55rem .75rem;border-radius:8px;cursor:pointer;
  font-size:.83rem;color:var(--muted);transition:all .15s;
  margin-bottom:1px;border:1px solid transparent;line-height:1.3
}
.sb-item:hover{background:var(--surface);color:var(--text)}
.sb-item.active{
  background:color-mix(in srgb,var(--lang) 9%,var(--surface));
  color:var(--lang);border-color:color-mix(in srgb,var(--lang) 22%,transparent);font-weight:600
}
.sb-num{font-family:'JetBrains Mono',monospace;font-size:.6rem;color:color-mix(in srgb,var(--muted) 60%,transparent);min-width:18px}

/* ── CONTENT ── */
.content-area{padding:2.5rem 3rem;overflow-y:auto;height:calc(100vh - 57px)}
.topic-panel{display:none}
.topic-panel.active{display:block;animation:slideR .28s ease}
.tp-title{font-size:clamp(1.6rem,3vw,2.2rem);font-weight:700;letter-spacing:-.035em;margin-bottom:.4rem}
.tp-sub{color:var(--muted);font-size:.9rem;line-height:1.7;margin-bottom:2rem;padding-bottom:1.5rem;border-bottom:1px solid var(--border)}
.sec{margin-bottom:2.25rem}
.sec-title{
  font-family:'JetBrains Mono',monospace;font-size:.65rem;letter-spacing:.1em;
  text-transform:uppercase;color:var(--lang);margin-bottom:.75rem;display:flex;align-items:center;gap:.5rem
}
.sec-title::after{content:'';flex:1;height:1px;background:color-mix(in srgb,var(--lang) 20%,transparent)}
.sec-text{font-size:.9rem;line-height:1.8;color:#44403c;margin-bottom:.875rem}
.concepts{display:grid;gap:.45rem;margin-bottom:1rem}
.ci{
  display:flex;gap:.75rem;align-items:flex-start;
  padding:.7rem .9rem;background:var(--surface);border:1px solid var(--border);
  border-radius:8px;font-size:.855rem
}
.ci-key{
  font-family:'JetBrains Mono',monospace;font-size:.75rem;
  background:color-mix(in srgb,var(--lang) 11%,transparent);
  color:var(--lang);padding:.15rem .45rem;border-radius:4px;white-space:nowrap;font-weight:500;flex-shrink:0
}
.ci-val{color:var(--muted);line-height:1.55;font-size:.84rem}
.tip{
  background:color-mix(in srgb,var(--lang) 7%,var(--surface));
  border:1px solid color-mix(in srgb,var(--lang) 22%,transparent);
  border-radius:8px;padding:.8rem 1rem;font-size:.855rem;line-height:1.65;
  color:var(--text);margin-bottom:1rem
}
.tip b{color:var(--lang)}

/* ── CODE BLOCK ── */
.cb{background:var(--code-bg);border-radius:10px;margin-bottom:1.5rem;overflow:hidden}
.cb-head{
  display:flex;align-items:center;justify-content:space-between;
  padding:.55rem 1rem;border-bottom:1px solid rgba(255,255,255,.07)
}
.cb-dots{display:flex;gap:5px}
.cb-dots span{width:8px;height:8px;border-radius:50%}
.cb-dots span:nth-child(1){background:#ff5f57}
.cb-dots span:nth-child(2){background:#febc2e}
.cb-dots span:nth-child(3){background:#28c840}
.cb-lang{font-family:'JetBrains Mono',monospace;font-size:.65rem;color:rgba(255,255,255,.35);letter-spacing:.06em}
.cb-body{
  padding:1.2rem 1.5rem;font-family:'JetBrains Mono',monospace;
  font-size:.79rem;line-height:1.75;color:#e4e4e7;overflow-x:auto;
  white-space:pre
}
.ct{color:#7dd3fc}.ca{color:#86efac}.cv{color:#fcd34d}
.cs{color:#c084fc}.cp{color:#67e8f9}.cu{color:#fca5a5}
.ck{color:#f9a8d4}.cf{color:#86efac}.cn{color:#fb923c}
.cc{color:rgba(255,255,255,.3);font-style:italic}.cty{color:#93c5fd}

/* ── ANIMATIONS ── */
@keyframes fadeIn{from{opacity:0}to{opacity:1}}
@keyframes fadeUp{from{opacity:0;transform:translateY(18px)}to{opacity:1;transform:translateY(0)}}
@keyframes slideR{from{opacity:0;transform:translateX(10px)}to{opacity:1;transform:translateX(0)}}

/* ── RESPONSIVE ── */
@media(max-width:900px){
  .lang-grid{grid-template-columns:repeat(3,1fr)}
  .det-body{grid-template-columns:1fr}
  .sidebar{position:static;height:auto;border-right:none;border-bottom:1px solid var(--border);
    padding:1rem;display:flex;flex-wrap:wrap;gap:.35rem;overflow-x:auto;white-space:nowrap}
  .sb-label{display:none}
  .sb-item{padding:.35rem .7rem;font-size:.78rem}
  .sb-num{display:none}
  .content-area{height:auto;padding:1.5rem}
}
@media(max-width:600px){
  .lang-grid{grid-template-columns:1fr 1fr}
  .home-h1{font-size:2rem}
  .content-area{padding:1.25rem}
}