:root{
  --bg:#f7f3ec;
  --bg-2:#efe9dd;
  --panel:#fcfaf6;
  --ink:#1c1a16;
  --ink-dim:#413c34;
  --muted:#847d71;
  --faint:#b0a898;
  --line:rgba(28,24,18,.10);
  --line-2:rgba(28,24,18,.17);
  --amber:#df540d;
  --amber-2:#f2691b;
  --amber-ghost:rgba(223,84,13,.09);
  --teal:#0b8f60;
  --teal-ghost:rgba(11,143,96,.10);
  --rail:284px;
  --ease:cubic-bezier(.22,.61,.36,1);
}
*{margin:0;padding:0;box-sizing:border-box}
html,body{height:100%}
body{
  background:var(--bg);
  color:var(--ink);
  font-family:'Manrope',-apple-system,BlinkMacSystemFont,sans-serif;
  -webkit-font-smoothing:antialiased;
  overflow:hidden;
}
::selection{background:var(--amber);color:#fff}

/* ---------- atmosphere ---------- */
.atmos{position:fixed;inset:0;z-index:0;pointer-events:none;overflow:hidden}
.glow{position:absolute;border-radius:50%;filter:blur(120px);opacity:.75}
.glow.a{width:52vw;height:52vw;top:-20vw;left:-14vw;background:radial-gradient(circle,rgba(255,150,80,.30),transparent 62%)}
.glow.b{width:46vw;height:46vw;bottom:-18vw;right:-10vw;background:radial-gradient(circle,rgba(70,200,150,.20),transparent 62%)}
.grid-lines{position:absolute;inset:0;opacity:.7;
  background-image:linear-gradient(var(--line) 1px,transparent 1px),linear-gradient(90deg,var(--line) 1px,transparent 1px);
  background-size:64px 64px;mask-image:radial-gradient(ellipse 80% 70% at 60% 40%,#000 30%,transparent 78%)}
.grain{position:absolute;inset:0;opacity:.04;mix-blend-mode:multiply;
  background-image:url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='140' height='140'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='.85' numOctaves='2'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)'/%3E%3C/svg%3E")}

/* ---------- shell ---------- */
.app{position:relative;z-index:1;display:grid;grid-template-columns:var(--rail) 1fr;height:100vh}

/* ---------- sidebar ---------- */
.rail{
  border-right:1px solid var(--line);
  background:linear-gradient(180deg,rgba(252,250,246,.82),rgba(247,243,236,.72));
  backdrop-filter:blur(8px);
  display:flex;flex-direction:column;height:100vh;overflow:hidden;
}
.brand{padding:26px 24px 20px;border-bottom:1px solid var(--line);display:flex;align-items:center;gap:12px}
.mark{width:30px;height:30px;flex:none;position:relative}
.mark svg{width:100%;height:100%;display:block}
.brand-txt .name{font-family:'Fraunces',serif;font-weight:600;font-size:1.12rem;letter-spacing:.01em;line-height:1;color:var(--ink)}
.brand-txt .ver{font-family:'JetBrains Mono',monospace;font-size:.62rem;color:var(--muted);letter-spacing:.14em;margin-top:5px;text-transform:uppercase}

.nav{flex:1;overflow-y:auto;padding:14px 12px;scrollbar-width:thin;scrollbar-color:var(--line-2) transparent}
.nav::-webkit-scrollbar{width:5px}
.nav::-webkit-scrollbar-thumb{background:var(--line-2);border-radius:9px}
.nav-item{
  display:flex;align-items:baseline;gap:12px;width:100%;text-align:left;
  padding:10px 12px;border:0;background:transparent;color:var(--muted);
  cursor:pointer;border-radius:9px;position:relative;
  font-family:inherit;font-size:.83rem;line-height:1.32;letter-spacing:.005em;
  transition:color .25s var(--ease),background .25s var(--ease);
}
.nav-item .idx{font-family:'JetBrains Mono',monospace;font-size:.68rem;color:var(--faint);flex:none;width:20px;transition:color .25s}
.nav-item:hover{color:var(--ink-dim);background:rgba(28,24,18,.035)}
.nav-item:hover .idx{color:var(--muted)}
.nav-item.on{color:var(--ink);background:var(--amber-ghost)}
.nav-item.on .idx{color:var(--amber)}
.nav-item.on:before{content:"";position:absolute;left:0;top:8px;bottom:8px;width:2.5px;border-radius:3px;background:var(--amber);box-shadow:0 0 12px var(--amber-ghost)}

.rail-foot{padding:16px 22px 20px;border-top:1px solid var(--line)}
.prog{height:3px;border-radius:3px;background:rgba(28,24,18,.09);overflow:hidden}
.prog i{display:block;height:100%;background:linear-gradient(90deg,var(--amber),var(--amber-2));border-radius:3px;transition:width .45s var(--ease)}
.rail-foot .lbl{display:flex;justify-content:space-between;font-family:'JetBrains Mono',monospace;font-size:.66rem;color:var(--muted);margin-top:10px;letter-spacing:.08em}

/* ---------- stage ---------- */
.stage{position:relative;overflow:hidden;height:100vh}
.slide{position:absolute;inset:0;padding:8vh 6vw 10vh;display:flex;flex-direction:column;justify-content:center;overflow-y:auto}
.slide::-webkit-scrollbar{width:0}

.kicker{display:inline-flex;align-items:center;gap:10px;font-family:'JetBrains Mono',monospace;
  font-size:.72rem;letter-spacing:.22em;text-transform:uppercase;color:var(--amber);font-weight:500;margin-bottom:26px}
.kicker:before{content:"";width:26px;height:1px;background:var(--amber);opacity:.8}
h1.title{font-family:'Fraunces',serif;font-weight:600;font-size:clamp(2.6rem,5.6vw,5.2rem);
  line-height:1.02;letter-spacing:-.022em;max-width:16ch;color:var(--ink)}
h2.title{font-family:'Fraunces',serif;font-weight:600;font-size:clamp(2rem,3.9vw,3.4rem);
  line-height:1.05;letter-spacing:-.02em;max-width:20ch;margin-bottom:8px;color:var(--ink)}
.title .hl{color:var(--amber);font-style:italic}
.lead{font-size:clamp(1.05rem,1.55vw,1.4rem);line-height:1.55;color:var(--ink-dim);max-width:58ch;margin-top:26px;font-weight:400}
.sub{font-size:1rem;line-height:1.6;color:var(--muted);max-width:60ch;margin-top:20px}
.foot-note{margin-top:auto;padding-top:34px;font-family:'JetBrains Mono',monospace;font-size:.68rem;color:var(--faint);letter-spacing:.06em}

/* cover */
.cover .title{font-size:clamp(3.4rem,9vw,8rem);max-width:none}
.cover-tags{display:flex;gap:10px;flex-wrap:wrap;margin-top:34px}
.tag{font-family:'JetBrains Mono',monospace;font-size:.72rem;letter-spacing:.08em;color:var(--ink-dim);
  border:1px solid var(--line-2);border-radius:100px;padding:7px 15px;background:rgba(255,255,255,.5)}
.tag.amber{border-color:rgba(223,84,13,.35);color:var(--amber);background:var(--amber-ghost)}

/* bullets */
.bullets{display:flex;flex-direction:column;gap:16px;margin-top:32px;max-width:62ch}
.bullets li{list-style:none;display:flex;gap:15px;font-size:clamp(.98rem,1.3vw,1.18rem);line-height:1.5;color:var(--ink-dim)}
.bullets li .dot{flex:none;width:8px;height:8px;border-radius:50%;background:var(--amber);margin-top:.55em}
.bullets li b{color:var(--ink);font-weight:600}
.bullets li .mono{font-family:'JetBrains Mono',monospace;font-size:.86em;color:var(--teal);
  background:var(--teal-ghost);padding:.1em .4em;border-radius:5px}

/* stat grid */
.stats{display:grid;grid-template-columns:repeat(auto-fit,minmax(180px,1fr));gap:18px;margin-top:38px;max-width:900px}
.stat{border:1px solid var(--line);border-radius:16px;padding:26px 24px;background:linear-gradient(160deg,rgba(255,255,255,.7),rgba(255,255,255,.25));position:relative;overflow:hidden;box-shadow:0 12px 34px rgba(28,24,18,.05)}
.stat:before{content:"";position:absolute;top:0;left:0;right:0;height:1px;background:linear-gradient(90deg,transparent,var(--line-2),transparent)}
.stat .n{font-family:'Fraunces',serif;font-weight:600;font-size:clamp(2rem,3.6vw,2.9rem);color:var(--amber);line-height:1}
.stat .n .u{font-size:.5em;color:var(--ink-dim);font-family:'Manrope';font-weight:600;margin-left:2px}
.stat .k{margin-top:12px;font-size:.9rem;color:var(--muted);line-height:1.4}

/* card grid (strategies / features) */
.cards{display:grid;grid-template-columns:repeat(auto-fill,minmax(230px,1fr));gap:14px;margin-top:34px;max-width:1000px}
.card{border:1px solid var(--line);border-radius:14px;padding:20px;background:rgba(255,255,255,.55);
  transition:border-color .3s var(--ease),transform .3s var(--ease),background .3s var(--ease),box-shadow .3s var(--ease)}
.card:hover{border-color:rgba(223,84,13,.4);transform:translateY(-3px);background:#fff;box-shadow:0 14px 32px rgba(28,24,18,.08)}
.card .ct{display:flex;align-items:center;gap:9px;font-family:'JetBrains Mono',monospace;font-size:.74rem;
  letter-spacing:.05em;color:var(--amber);text-transform:uppercase;margin-bottom:11px}
.card .ct .n{width:20px;height:20px;border:1px solid var(--line-2);border-radius:6px;display:grid;place-items:center;font-size:.66rem;color:var(--muted)}
.card h3{font-family:'Manrope';font-weight:700;font-size:1.02rem;color:var(--ink);margin-bottom:7px;letter-spacing:-.01em}
.card p{font-size:.86rem;line-height:1.5;color:var(--muted)}

/* two-column split with diagram */
.split{display:grid;grid-template-columns:1.05fr .95fr;gap:5vw;align-items:center;margin-top:10px}
.split .txt{min-width:0}
@media(max-width:1080px){.split{grid-template-columns:1fr}}

/* text + screenshot split */
.shotwrap{display:grid;grid-template-columns:0.82fr 1.18fr;gap:3.4vw;align-items:center;margin-top:8px}
.shotwrap .txt{min-width:0}
.shotwrap .txt .kicker{margin-bottom:20px}
.shotwrap .txt h2.title{margin-bottom:6px}
.shotwrap .lead{margin-top:18px;font-size:clamp(1rem,1.25vw,1.22rem)}
.shotwrap .bullets{margin-top:22px;gap:12px}
.shotwrap .bullets li{font-size:clamp(.92rem,1.1vw,1.05rem)}
.shotwrap .sub{margin-top:16px}
@media(max-width:1080px){.shotwrap{grid-template-columns:1fr;gap:30px}}

/* browser frame */
.frame{border-radius:13px;overflow:hidden;border:1px solid var(--line-2);
  background:#fff;box-shadow:0 30px 70px -20px rgba(28,24,18,.35),0 8px 20px rgba(28,24,18,.08);
  transform:perspective(1600px) rotateY(-3deg);transition:transform .5s var(--ease)}
.frame:hover{transform:perspective(1600px) rotateY(0deg)}
.frame .chrome{display:flex;align-items:center;gap:8px;padding:10px 14px;background:#f4f1eb;border-bottom:1px solid var(--line)}
.frame .chrome .dots{display:flex;gap:6px}
.frame .chrome .dots i{width:11px;height:11px;border-radius:50%;display:block}
.frame .chrome .dots i:nth-child(1){background:#ff5f57}
.frame .chrome .dots i:nth-child(2){background:#febc2e}
.frame .chrome .dots i:nth-child(3){background:#28c840}
.frame .chrome .url{flex:1;margin-left:8px;background:#fff;border:1px solid var(--line);border-radius:7px;
  padding:5px 12px;font-family:'JetBrains Mono',monospace;font-size:.68rem;color:var(--muted);
  white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.frame .url b{color:var(--ink-dim);font-weight:500}
.frame img{width:100%;display:block}

/* cover with hero shot */
.cover-split{display:grid;grid-template-columns:0.9fr 1.1fr;gap:3.6vw;align-items:center}
.cover-split .frame{transform:perspective(1800px) rotateY(-5deg) rotateX(2deg)}
.cover-split h1.title{font-size:clamp(2.8rem,5.2vw,4.8rem);max-width:none}
.cover-split .lead{margin-top:22px}
@media(max-width:1080px){.cover-split{grid-template-columns:1fr}}

/* chips (compact tag list) */
.chips{display:flex;flex-wrap:wrap;gap:9px;margin-top:24px;max-width:52ch}
.chip{font-family:'JetBrains Mono',monospace;font-size:.76rem;letter-spacing:.02em;color:var(--ink-dim);
  border:1px solid var(--line-2);border-radius:8px;padding:7px 12px;background:rgba(255,255,255,.5)}

/* routing diagram */
.diagram{position:relative;width:100%;max-width:520px;aspect-ratio:1/.82;margin-inline:auto}
.diagram svg{width:100%;height:100%;overflow:visible}
.node-lbl{font-family:'JetBrains Mono',monospace;font-size:9px;fill:var(--ink-dim);letter-spacing:.04em}
.hub-lbl{font-family:'Fraunces',serif;font-size:15px;fill:var(--ink);font-weight:600}
.flow{stroke-dasharray:5 7;animation:dash 1.4s linear infinite}
@keyframes dash{to{stroke-dashoffset:-24}}

/* pills row */
.pills{display:flex;flex-wrap:wrap;gap:11px;margin-top:34px;max-width:800px}
.pill{display:inline-flex;align-items:center;gap:9px;border:1px solid var(--line-2);border-radius:100px;
  padding:10px 18px;font-size:.92rem;color:var(--ink-dim);background:rgba(255,255,255,.55)}
.pill .d{width:7px;height:7px;border-radius:50%;background:var(--teal)}

/* code block */
.code{margin-top:30px;border:1px solid var(--line);border-radius:14px;background:#fff;overflow:hidden;max-width:720px;box-shadow:0 14px 34px rgba(28,24,18,.06)}
.code .bar{display:flex;align-items:center;gap:7px;padding:12px 16px;border-bottom:1px solid var(--line)}
.code .bar i{width:11px;height:11px;border-radius:50%;background:var(--faint)}
.code .bar span{font-family:'JetBrains Mono',monospace;font-size:.7rem;color:var(--muted);margin-left:8px}
.code pre{padding:18px 20px;font-family:'JetBrains Mono',monospace;font-size:.86rem;line-height:1.7;color:var(--ink-dim);overflow-x:auto}
.code .c-key{color:var(--amber)}
.code .c-str{color:var(--teal)}
.code .c-com{color:var(--faint)}

/* ---------- controls ---------- */
.ctrl{position:fixed;bottom:26px;right:34px;z-index:20;display:flex;align-items:center;gap:14px}
.ctrl .num{font-family:'JetBrains Mono',monospace;font-size:.8rem;color:var(--muted);letter-spacing:.08em}
.ctrl .num b{color:var(--ink)}
.ctrl button{width:42px;height:42px;border-radius:11px;border:1px solid var(--line-2);background:rgba(255,255,255,.7);
  backdrop-filter:blur(8px);color:var(--ink-dim);cursor:pointer;display:grid;place-items:center;
  transition:all .22s var(--ease);box-shadow:0 4px 14px rgba(28,24,18,.05)}
.ctrl button:hover{border-color:var(--amber);color:var(--amber);background:var(--amber-ghost)}
.ctrl button:active{transform:scale(.93)}
.ctrl button:disabled{opacity:.35;cursor:default;box-shadow:none}

/* ---------- enter animations ---------- */
.slide.enter > *{opacity:0;transform:translateY(22px);animation:rise .72s var(--ease) forwards}
.slide.enter > *:nth-child(1){animation-delay:.05s}
.slide.enter > *:nth-child(2){animation-delay:.13s}
.slide.enter > *:nth-child(3){animation-delay:.21s}
.slide.enter > *:nth-child(4){animation-delay:.29s}
.slide.enter > *:nth-child(5){animation-delay:.37s}
.slide.enter > *:nth-child(6){animation-delay:.45s}
@keyframes rise{to{opacity:1;transform:none}}
.stagger > *{opacity:0;transform:translateY(16px) scale(.99);animation:rise2 .6s var(--ease) forwards}
.stagger.enter > *:nth-child(1){animation-delay:.30s}
.stagger.enter > *:nth-child(2){animation-delay:.37s}
.stagger.enter > *:nth-child(3){animation-delay:.44s}
.stagger.enter > *:nth-child(4){animation-delay:.51s}
.stagger.enter > *:nth-child(5){animation-delay:.58s}
.stagger.enter > *:nth-child(6){animation-delay:.65s}
.stagger.enter > *:nth-child(7){animation-delay:.72s}
.stagger.enter > *:nth-child(8){animation-delay:.79s}
.stagger.enter > *:nth-child(9){animation-delay:.86s}
.stagger.enter > *:nth-child(10){animation-delay:.93s}
@keyframes rise2{to{opacity:1;transform:none}}

@media(max-width:820px){
  .app{grid-template-columns:1fr}
  .rail{position:fixed;left:0;top:0;bottom:0;width:var(--rail);z-index:30;transform:translateX(-100%);transition:transform .3s}
  .slide{padding:10vh 7vw}
}