/* Sera — landing. Design language: slides/index.html (palette, spark), Apple-quiet. */
*{margin:0;padding:0;box-sizing:border-box}
:root{
  --bg:#FBFBFD;
  --card:#FFFFFF;
  --field:#F5F5F7;
  --ink:#1D1D1F;
  --ink2:rgba(29,29,31,.64);
  --ink3:rgba(29,29,31,.42);
  --line:rgba(29,29,31,.10);
  --violet:#7A3BFF;
  --blue:#2E5BFF;
  --orange:#FF4B2E;
  --ease:cubic-bezier(.22,1,.36,1);
  --font:-apple-system,BlinkMacSystemFont,"SF Pro Display","SF Pro Text","Segoe UI",system-ui,sans-serif;
  --mono:ui-monospace,"SF Mono","Cascadia Code",Menlo,Consolas,monospace;
}
html{scroll-behavior:smooth}
body{background:var(--bg);color:var(--ink);font-family:var(--font);-webkit-font-smoothing:antialiased;text-rendering:optimizeLegibility}
::selection{background:rgba(122,59,255,.18)}
a{color:inherit;text-decoration:none}
button{font-family:inherit;cursor:pointer}
img,svg{display:block}
:focus-visible{outline:2px solid var(--violet);outline-offset:3px}
html{scrollbar-color:rgba(29,29,31,.22) transparent}
input::placeholder,textarea::placeholder{color:var(--ink3)}

.wrap{max-width:1080px;margin:0 auto;padding:0 28px}
section{position:relative}

/* ---------- type ---------- */
h1,h2{font-weight:700;letter-spacing:-.03em;line-height:1.06}
.h2{font-size:clamp(38px,5vw,60px);margin-top:26px}
.lede{margin-top:26px;font-size:19px;line-height:1.62;color:var(--ink2);max-width:58ch}
.mono{font-family:var(--mono)}
.caption{margin-top:22px;font-size:14px;color:var(--ink3)}

/* ---------- reveal system ---------- */
[data-reveal]{opacity:0;transform:translateY(26px);transition:opacity .9s var(--ease),transform .9s var(--ease);transition-delay:calc(var(--d,0)*90ms)}
[data-reveal].in{opacity:1;transform:none}
.lm{display:block;overflow:hidden;padding-bottom:.08em;margin-bottom:-.08em}
.lm>span{display:block;transform:translateY(112%);transition:transform 1.05s var(--ease);transition-delay:calc(var(--d,0)*110ms)}
[data-reveal].in .lm>span,.lm.in>span{transform:none}

/* ---------- keyframes (quiet) ---------- */
@keyframes shake{0%,100%{transform:translateX(0)}20%{transform:translateX(-6px)}40%{transform:translateX(5px)}60%{transform:translateX(-3px)}80%{transform:translateX(2px)}}
/* ---------- nav ---------- */
.nav{position:fixed;top:0;left:0;right:0;z-index:50;transition:background-color .5s var(--ease),border-color .5s var(--ease),backdrop-filter .5s var(--ease);border-bottom:1px solid transparent}
.nav.scrolled{background:rgba(251,251,253,.78);-webkit-backdrop-filter:saturate(180%) blur(18px);backdrop-filter:saturate(180%) blur(18px);border-bottom-color:var(--line)}
.nav-in{max-width:1180px;margin:0 auto;padding:0 28px;height:60px;display:flex;align-items:center;justify-content:space-between;gap:20px}
.brand{display:flex;align-items:center;gap:9px;font-size:16px;font-weight:600;letter-spacing:-.01em}
.brand svg{width:17px;height:17px}
.nav-links{display:flex;align-items:center;gap:30px}
.nav-links a{font-size:14px;color:var(--ink2);transition:color .3s}
.nav-links a:hover{color:var(--ink)}
.btn{display:inline-flex;align-items:center;gap:8px;border:none;border-radius:8px;font-size:15px;font-weight:500;letter-spacing:-.01em;padding:12px 24px;white-space:nowrap;transition:transform .35s var(--ease),background-color .35s var(--ease),border-color .35s var(--ease),color .35s var(--ease)}
.btn:active{transform:scale(.985)}
.btn--ghost{background:transparent;color:var(--ink);border:1px solid var(--line);padding:9px 18px;font-size:14px}
.btn--ghost:hover{border-color:rgba(29,29,31,.32)}
.btn--dark{background:var(--ink);color:#fff}
.btn--dark:hover{background:#000;transform:translateY(-1px)}
.btn .arr{transition:transform .35s var(--ease)}
.btn:hover .arr{transform:translateX(3px)}
@media (max-width:720px){.nav-links a{display:none}.nav-links .btn{display:inline-flex}}

/* ---------- hero ---------- */
.hero{min-height:100svh;display:flex;align-items:center;justify-content:center;overflow:hidden}
.hero-in{position:relative;z-index:1;text-align:center;padding:120px 24px 90px;will-change:transform,opacity}
.hero .spark{width:48px;height:48px;margin:0 auto 34px}
.hero .herotag{margin:30px auto 0;max-width:40ch;font-size:18px;font-weight:500;letter-spacing:-.01em}
.hero h1{margin-top:30px;font-size:clamp(48px,8.6vw,96px);letter-spacing:-.03em}
.hero .lede{margin:30px auto 0;max-width:52ch;font-size:20px}
.hero-cta{margin-top:44px;display:flex;align-items:center;justify-content:center;gap:18px;flex-wrap:wrap}
.hero-cta .btn{padding:15px 30px;font-size:16px}
.tlink{display:inline-flex;align-items:center;gap:8px;font-size:16px;font-weight:500;color:var(--ink2);transition:color .3s}
.tlink:hover{color:var(--ink)}
.tlink .arr{display:inline-block;transition:transform .35s var(--ease)}
.tlink:hover .arr{transform:translateY(3px)}
.hero-tools{margin-top:56px;font-size:13px;letter-spacing:.02em;color:var(--ink3)}

/* ---------- 01 · the gold ---------- */
.gold{padding:190px 0 150px}
.gold-grid{display:grid;grid-template-columns:1fr 1.05fr;gap:72px;align-items:center;margin-top:8px}
.msgcard{position:relative;background:var(--card);border-radius:16px;padding:24px 28px 26px;box-shadow:0 24px 60px -28px rgba(29,29,31,.18)}
.msghead{display:flex;justify-content:space-between;font-family:var(--mono);font-size:12px;color:var(--ink3);padding-bottom:14px;border-bottom:1px solid var(--line)}
.msg{display:flex;gap:14px;margin-top:18px}
.ava{flex:none;width:36px;height:36px;border-radius:50%;display:grid;place-items:center;font-size:14px;font-weight:700;background:color-mix(in srgb,var(--c,#5B6472) 14%,#fff);color:var(--c,#5B6472)}
.msgmeta{display:flex;gap:8px;align-items:baseline}
.msgmeta b{font-size:14px;font-weight:600}
.msgmeta span{font-family:var(--mono);font-size:11px;color:var(--ink3)}
.msg p{margin-top:3px;font-size:15.5px;line-height:1.5;color:var(--ink)}
.msg p code{font-family:var(--mono);font-size:13px;background:rgba(29,29,31,.06);padding:2px 6px;border-radius:5px}
.msg--gold{background:rgba(46,91,255,.045);border:1px solid rgba(46,91,255,.22);border-radius:12px;padding:13px 15px;margin-left:-15px;margin-right:-15px}
.goldtag{position:absolute;top:-14px;right:20px;display:flex;align-items:center;gap:7px;background:var(--card);border:1px solid rgba(46,91,255,.4);color:var(--blue);border-radius:999px;padding:6px 13px;font-family:var(--mono);font-size:11px;letter-spacing:.14em;text-transform:uppercase}
.goldtag svg{width:11px;height:11px}
@media (max-width:900px){.gold-grid{grid-template-columns:1fr;gap:56px}}

/* ---------- 02 · what sera does (sticky walkthrough) ---------- */
.product{padding:150px 0 120px;border-top:1px solid var(--line)}
.walk{display:grid;grid-template-columns:1fr 1fr;gap:80px;align-items:start;margin-top:24px}
.steps{display:flex;flex-direction:column}
.step{min-height:92vh;display:flex;flex-direction:column;justify-content:center;opacity:.32;transition:opacity .8s var(--ease)}
.step.on{opacity:1}
.step .snum{font-size:13px;font-weight:600;letter-spacing:.08em;text-transform:uppercase;color:var(--ink2);display:flex;align-items:center;gap:12px}
.step .snum::after{content:"";flex:1;max-width:56px;height:1px;background:var(--line)}
.step h3{margin-top:20px;font-size:clamp(28px,3.4vw,40px);font-weight:700;letter-spacing:-.03em}
.step p{margin-top:18px;font-size:17px;line-height:1.62;color:var(--ink2);max-width:44ch}
.mockcol{position:sticky;top:0;height:100svh;display:flex;align-items:center}
.mock{position:relative;width:100%;height:min(600px,72svh)}
.mock .state{position:absolute;inset:0;display:flex;align-items:center;opacity:0;transform:translateY(14px) scale(.995);transition:opacity .8s var(--ease),transform .8s var(--ease);pointer-events:none}
.mock[data-step="0"] .state:nth-child(1),.mock[data-step="1"] .state:nth-child(2),.mock[data-step="2"] .state:nth-child(3){opacity:1;transform:none;pointer-events:auto}
.mock .msgcard{width:100%;display:flex;flex-direction:column;overflow:hidden;padding:26px 30px 24px}
.idxline{display:flex;align-items:center;gap:11px;font-family:var(--mono);font-size:13px;color:var(--ink2);padding:9px 0;border-bottom:1px dashed rgba(29,29,31,.07)}
.idxline:last-of-type{border-bottom:none}
.idxline .ok{margin-left:auto;font-size:11px;letter-spacing:.1em;text-transform:uppercase;color:var(--blue)}
.idxline i{flex:none;width:7px;height:7px;border-radius:50%;background:var(--violet);opacity:.65}
.bottag{font-family:var(--mono);font-size:9.5px;letter-spacing:.1em;text-transform:uppercase;color:var(--violet);border:1px solid rgba(122,59,255,.35);border-radius:999px;padding:1px 7px}
.botava{flex:none;width:34px;height:34px;border-radius:50%;background:var(--card);border:1.5px solid rgba(122,59,255,.5);display:grid;place-items:center;color:var(--violet)}
.botava svg{width:15px;height:15px}
.steps-ol{margin-top:10px;padding-left:19px;font-size:14px;line-height:1.7;color:var(--ink)}
.srcs{margin-top:14px;display:flex;flex-direction:column;gap:7px}
.srcs span{font-family:var(--mono);font-size:12px;color:var(--ink2);display:flex;gap:9px;align-items:center}
.srcs i{flex:none;width:6px;height:6px;border-radius:50%;background:var(--violet);opacity:.65}
.asrc{margin-top:auto;padding-top:14px;font-family:var(--mono);font-size:11px;color:var(--ink3)}
.cmd{font-family:var(--mono);font-size:13px;background:rgba(29,29,31,.06);padding:3px 8px;border-radius:6px}
.done{display:inline-flex;align-items:center;gap:9px;margin-top:14px;font-family:var(--mono);font-size:12px;color:#1F4DE6;border:1px solid rgba(46,91,255,.3);background:rgba(46,91,255,.05);border-radius:10px;padding:9px 13px;width:fit-content}
.done svg{width:12px;height:12px}
@media (max-width:900px){
  .walk{grid-template-columns:1fr;gap:40px}
  .step{min-height:0;opacity:1;padding:34px 0}
  .mockcol{position:relative;top:0;height:auto;padding:10px 0}
  .mock{height:560px}
}

/* ---------- 03 · beliefs ---------- */
.beliefs{border-top:1px solid var(--line);background:#F4F4F6}
.belief{min-height:120vh;min-height:120svh;position:relative;padding:20vh 0 0;text-align:center}
.belief .lock{position:sticky;top:50%;transform:translateY(-50%)}
.belief h3{font-size:clamp(32px,4.6vw,54px);font-weight:700;letter-spacing:-.03em;line-height:1.14;max-width:22ch;margin:0 auto}
.belief h3 .acc{color:var(--violet)}
.belief .bsub{margin:18px auto 0;font-size:16px;color:var(--ink2);max-width:52ch}
@media (max-width:720px){.belief{padding-top:24vh}}

/* ---------- 04 · design partners ---------- */
.contact{padding:160px 0 150px;border-top:1px solid var(--line)}
.contact-grid{display:grid;grid-template-columns:1fr 1fr;gap:72px;align-items:start;margin-top:8px}
.formcard{background:var(--card);border-radius:16px;padding:38px;box-shadow:0 24px 60px -28px rgba(29,29,31,.18)}
.frow{margin-bottom:18px}
.frow label{display:block;font-size:13px;font-weight:600;margin-bottom:8px;color:var(--ink)}
.frow label em{font-style:normal;font-weight:400;color:var(--ink3)}
.frow input,.frow textarea{width:100%;font-family:inherit;font-size:15px;color:var(--ink);background:var(--field);border:1px solid transparent;border-radius:12px;padding:13px 15px;outline:none;transition:border-color .3s,box-shadow .3s,background-color .3s}
.frow input:focus,.frow textarea:focus{border-color:rgba(122,59,255,.55);box-shadow:0 0 0 4px rgba(122,59,255,.12);background:#fff}
.frow textarea{resize:vertical;min-height:96px}
.formcard .btn--dark{width:100%;justify-content:center;padding:15px 30px;font-size:16px}
.formnote{margin-top:20px;font-size:14.5px;line-height:1.9;color:var(--ink2);display:flex;flex-direction:column;gap:6px}
.euline{display:flex;gap:10px;align-items:flex-start;margin-top:20px;padding:13px 15px;border:1px solid rgba(46,91,255,.22);background:rgba(46,91,255,.045);border-radius:12px;font-size:13.5px;line-height:1.5;color:var(--ink2)}
.euline svg{flex:none;width:14px;height:14px;margin-top:2px;color:var(--blue)}
.formerr{margin-top:14px;font-size:13.5px;color:var(--orange);display:none}
.formerr.show{display:block}
.formdone{display:none;flex-direction:column;align-items:center;justify-content:center;text-align:center;min-height:380px;gap:18px}
.formdone .spark{width:56px;height:56px}
.formdone h3{font-size:24px;font-weight:700;letter-spacing:-.02em}
.formdone p{font-size:15px;color:var(--ink2);max-width:36ch;line-height:1.55}
.formcard.done .formlive{display:none}
.formcard.done .formdone{display:flex}
@media (max-width:900px){.contact-grid{grid-template-columns:1fr;gap:48px}}


/* ---------- footer ---------- */
.foot{border-top:1px solid var(--line);padding:56px 0 60px}
.foot-in{display:flex;align-items:center;justify-content:space-between;gap:24px;flex-wrap:wrap}
.foot .brand{font-size:15px}
.foot .brand svg{width:18px;height:18px}
.foot-links{display:flex;gap:26px;align-items:center}
.foot-links a{font-size:13.5px;color:var(--ink2);transition:color .3s}
.foot-links a:hover{color:var(--ink)}
.foot .epi{margin-top:48px;font-size:15px;color:var(--ink2)}
.foot .copy{margin-top:14px;font-size:13px;color:var(--ink3)}

/* ---------- anchor offset under fixed nav ---------- */
[id]{scroll-margin-top:76px}

/* ---------- /app — control plane login (dark) ---------- */
.page-app{background:#0A0A0C;min-height:100svh;display:flex;flex-direction:column;align-items:center;justify-content:center;position:relative;overflow:hidden;color:#F5F5F7}
.app-in{position:relative;z-index:1;width:100%;max-width:400px;padding:0 24px;text-align:center}
.app-in .spark{width:44px;height:44px;margin:0 auto 26px}
.app-in .word{font-size:22px;font-weight:700;letter-spacing:-.02em}
.app-in .plane{margin-top:8px;font-family:var(--mono);font-size:11px;letter-spacing:.22em;text-transform:uppercase;color:rgba(245,245,247,.42)}
.appcard{margin-top:36px;background:rgba(255,255,255,.045);border:1px solid rgba(255,255,255,.1);border-radius:20px;padding:30px;text-align:left;-webkit-backdrop-filter:blur(14px);backdrop-filter:blur(14px)}
.appcard h2{font-size:17px;font-weight:600;letter-spacing:-.01em;text-align:center}
.appcard .sub{margin-top:7px;font-size:13px;color:rgba(245,245,247,.45);text-align:center}
.appcard .frow{margin-top:20px}
.appcard .frow label{color:rgba(245,245,247,.7)}
.appcard .frow input{background:rgba(255,255,255,.06);border-color:rgba(255,255,255,.1);color:#F5F5F7;padding:12px 14px}
.appcard .frow input::placeholder{color:rgba(245,245,247,.28)}
.appcard .frow input:focus{border-color:rgba(122,59,255,.7);box-shadow:0 0 0 4px rgba(122,59,255,.16);background:rgba(255,255,255,.08)}
.appcard .btn{width:100%;justify-content:center;background:#F5F5F7;color:#0A0A0C;margin-top:24px;padding:13px 24px;font-size:15px}
.appcard .btn:hover{background:#fff;transform:translateY(-1px)}
.appnote{margin-top:16px;font-family:var(--mono);font-size:11.5px;line-height:1.7;color:rgba(245,245,247,.4);display:none}
.appnote.show{display:block}
.appcard.shake{animation:shake .5s var(--ease)}
.app-back{display:inline-block;margin-top:34px;font-size:13.5px;color:rgba(245,245,247,.45);transition:color .3s}
.app-back:hover{color:#F5F5F7}
.app-foot{position:absolute;bottom:26px;left:0;right:0;text-align:center;font-size:11px;color:rgba(245,245,247,.25);z-index:1}

/* ---------- 404 ---------- */
.page-404{min-height:100svh;display:flex;align-items:center;justify-content:center;text-align:center}
.p4-in .spark{width:44px;height:44px;margin:0 auto 24px}
.p4-in h1{font-size:44px;letter-spacing:-.03em}
.p4-in p{margin-top:14px;font-size:16px;color:var(--ink2)}
.p4-in .tlink{margin-top:28px}

/* ---------- reduced motion ---------- */
@media (prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  *,*::before,*::after{animation:none!important;transition:none!important}
  [data-reveal]{opacity:1;transform:none}
  .lm>span{transform:none}
  .step{opacity:1}
}