/* =========================================================================
   YSRA — Identity system
   Two specialists, overlapping. The verified core is solid.
   ========================================================================= */

/* ---- Fonts ---- */
@import url('https://fonts.googleapis.com/css2?family=Space+Grotesk:wght@400;500;600;700&family=Hanken+Grotesk:wght@400;500;600;700&family=JetBrains+Mono:wght@400;500;600&display=swap');

/* ===================== TOKENS ===================== */
/* Light is the default. Dark is opt-in via [data-theme="dark"]. */
:root{
  --bg:#F6F7F9;
  --bg-2:#EDEFF3;
  --surface:#FFFFFF;
  --panel:#F0F2F5;
  --panel-2:#E6EAEF;
  --text:#14161C;
  --text-soft:#3E434E;
  --muted:#777C86;
  --line:rgba(20,22,28,.09);
  --line-strong:rgba(20,22,28,.17);
  --accent:#1C4A45;
  --accent-2:#2C6E63;
  --accent-ink:#FFFFFF;
  --accent-glow:rgba(28,74,69,.14);
  --signal:#C6502B;
  --core:#1C4A45;
  --ring:#14161C;
  --shadow:0 1px 2px rgba(20,22,28,.05), 0 12px 40px rgba(20,22,28,.07);
  --shadow-lg:0 2px 4px rgba(20,22,28,.06), 0 30px 80px rgba(20,22,28,.13);
  color-scheme: light;
}
[data-theme="dark"]{
  --bg:#0A0B0D;
  --bg-2:#070809;
  --surface:#101218;
  --panel:#14161D;
  --panel-2:#1A1D26;
  --text:#ECEEF1;
  --text-soft:#AfB3BD;
  --muted:#71757F;
  --line:rgba(255,255,255,.08);
  --line-strong:rgba(255,255,255,.16);
  --accent:#45A491;          /* verified teal, tuned for dark */
  --accent-2:#5FC9B2;
  --accent-ink:#06120F;      /* text on accent fills */
  --accent-glow:rgba(69,164,145,.20);
  --signal:#E0734A;          /* terracotta — used for mono/internal labels */
  --core:#45A491;            /* logo verified core */
  --ring:#ECEEF1;            /* logo rings */
  --shadow:0 1px 2px rgba(0,0,0,.4), 0 16px 50px rgba(0,0,0,.5);
  --shadow-lg:0 2px 6px rgba(0,0,0,.5), 0 40px 100px rgba(0,0,0,.65);
  color-scheme: dark;
}

/* ===================== RESET ===================== */
*,*::before,*::after{box-sizing:border-box;margin:0;padding:0}
html{-webkit-text-size-adjust:100%;scroll-behavior:smooth}
@media (prefers-reduced-motion: reduce){html{scroll-behavior:auto}}
body{
  background:var(--bg);
  color:var(--text);
  font-family:'Hanken Grotesk',system-ui,sans-serif;
  font-size:17px;
  line-height:1.6;
  -webkit-font-smoothing:antialiased;
  text-rendering:optimizeLegibility;
  overflow-x:hidden;
  transition:background .6s cubic-bezier(.4,0,.2,1), color .6s cubic-bezier(.4,0,.2,1);
}
img,svg{display:block;max-width:100%}
a{color:inherit;text-decoration:none}
button{font-family:inherit;cursor:pointer;border:none;background:none;color:inherit}
::selection{background:var(--accent);color:var(--accent-ink)}

/* ===================== TYPE ===================== */
.display,h1,h2,h3{font-family:'Space Grotesk',system-ui,sans-serif;font-weight:600;letter-spacing:-.03em;line-height:1.04;text-wrap:balance}
h1{font-size:clamp(2.7rem,7vw,5.8rem);letter-spacing:-.04em}
h2{font-size:clamp(2rem,4.4vw,3.5rem)}
h3{font-size:clamp(1.35rem,2.3vw,1.9rem);line-height:1.14;letter-spacing:-.02em}
.serif-i{font-style:normal;color:var(--accent)}
p{text-wrap:pretty}
.lead{font-size:clamp(1.1rem,1.5vw,1.32rem);line-height:1.55;color:var(--text-soft);max-width:48ch}
.mono{font-family:'JetBrains Mono',ui-monospace,monospace}
.eyebrow{
  font-family:'JetBrains Mono',monospace;
  font-size:.72rem;font-weight:500;letter-spacing:.26em;text-transform:uppercase;
  color:var(--muted);display:inline-flex;align-items:center;gap:.7em;white-space:nowrap;
}
.eyebrow::before{content:"";width:1.6em;height:1px;background:var(--accent);display:inline-block}
.eyebrow.no-rule::before{display:none}

/* ===================== LAYOUT ===================== */
.wrap{width:min(1240px,92vw);margin-inline:auto}
.wrap-narrow{width:min(880px,92vw);margin-inline:auto}
section{position:relative}
.pad{padding-block:clamp(5rem,11vw,9rem)}
.pad-sm{padding-block:clamp(3rem,6vw,5rem)}
.divider{height:1px;background:var(--line);border:0}

/* ===================== BUTTONS ===================== */
.btn{
  --pad-x:1.5rem;
  display:inline-flex;align-items:center;gap:.6em;
  font-weight:600;font-size:.98rem;letter-spacing:-.01em;
  padding:.85em var(--pad-x);border-radius:10px;
  position:relative;white-space:nowrap;
  transition:transform .25s cubic-bezier(.34,1.56,.64,1), background .3s, color .3s, box-shadow .3s, border-color .3s;
  will-change:transform;
}
.btn-primary{background:var(--accent);color:var(--accent-ink);box-shadow:0 1px 0 rgba(255,255,255,.1) inset, 0 8px 30px var(--accent-glow)}
.btn-primary:hover{box-shadow:0 1px 0 rgba(255,255,255,.16) inset, 0 12px 40px var(--accent-glow)}
.btn-ghost{border:1px solid var(--line-strong);color:var(--text)}
.btn-ghost:hover{border-color:var(--accent);color:var(--accent)}
.btn .arw{transition:transform .3s cubic-bezier(.34,1.56,.64,1)}
.btn:hover .arw{transform:translateX(3px)}
.btn-lg{font-size:1.05rem;padding:1.02em 1.7em}
.link-arrow{display:inline-flex;align-items:center;gap:.45em;color:var(--accent);font-weight:600;font-size:.96rem}
.link-arrow .arw{transition:transform .3s cubic-bezier(.34,1.56,.64,1)}
.link-arrow:hover .arw{transform:translateX(4px)}

/* ===================== NAV ===================== */
.nav{
  position:fixed;top:0;left:0;right:0;z-index:90;
  transition:background .4s, border-color .4s, backdrop-filter .4s;
  border-bottom:1px solid transparent;
}
.nav.scrolled{
  background:color-mix(in srgb, var(--bg) 75%, transparent);
  backdrop-filter:blur(18px) saturate(1.4);
  border-bottom:1px solid var(--line);
}
.nav-inner{display:flex;align-items:center;justify-content:space-between;height:74px}
.brand{display:flex;align-items:center;gap:.6rem;font-family:'Space Grotesk',sans-serif;font-weight:600;font-size:1.35rem;letter-spacing:-.02em}
.brand .ymark{width:28px;height:28px}
.nav-links{display:flex;align-items:center;gap:2.2rem}
.nav-links a{font-size:.95rem;color:var(--text-soft);font-weight:500;position:relative;transition:color .25s}
.nav-links a::after{content:"";position:absolute;left:0;bottom:-4px;width:0;height:1.5px;background:var(--accent);transition:width .3s cubic-bezier(.4,0,.2,1)}
.nav-links a:hover{color:var(--text)}
.nav-links a:hover::after,.nav-links a.active::after{width:100%}
.nav-links a.active{color:var(--text)}
.nav-right{display:flex;align-items:center;gap:1.1rem}
.theme-toggle{
  width:42px;height:42px;border-radius:10px;border:1px solid var(--line-strong);
  display:grid;place-items:center;transition:border-color .3s, transform .4s, background .3s;
}
.theme-toggle:hover{border-color:var(--accent)}
.theme-toggle svg{width:18px;height:18px}
.icon-moon{display:block}
.icon-sun{display:none}
[data-theme="dark"] .icon-moon{display:none}
[data-theme="dark"] .icon-sun{display:block}
.nav-burger{display:none;width:42px;height:42px;border-radius:10px;border:1px solid var(--line-strong);place-items:center}
.nav-burger span{display:block;width:18px;height:1.6px;background:var(--text);position:relative}
.nav-burger span::before,.nav-burger span::after{content:"";position:absolute;left:0;width:18px;height:1.6px;background:var(--text)}
.nav-burger span::before{top:-6px}.nav-burger span::after{top:6px}

/* ===================== BADGES / CHIPS ===================== */
.chip{
  display:inline-flex;align-items:center;gap:.5em;
  font-family:'JetBrains Mono',monospace;font-size:.74rem;font-weight:500;letter-spacing:.04em;
  padding:.45em .85em;border-radius:8px;border:1px solid var(--line-strong);color:var(--text-soft);
  background:color-mix(in srgb, var(--surface) 50%, transparent);
}
.dot{width:7px;height:7px;border-radius:50%;background:var(--accent);position:relative}
.dot.live::after{content:"";position:absolute;inset:-4px;border-radius:50%;border:1px solid var(--accent);animation:ping 2s ease-out infinite}
@keyframes ping{0%{transform:scale(.6);opacity:.9}100%{transform:scale(1.9);opacity:0}}

/* ===================== CARDS ===================== */
.card{
  background:var(--surface);border:1px solid var(--line);border-radius:14px;
  box-shadow:var(--shadow);transition:transform .4s cubic-bezier(.2,.8,.2,1), box-shadow .4s, border-color .4s;
}
.card:hover{transform:translateY(-4px);box-shadow:var(--shadow-lg);border-color:var(--line-strong)}

/* ===================== PHYSICS CURSOR ===================== */
.cursor-dot,.cursor-ring{position:fixed;top:0;left:0;z-index:9999;pointer-events:none;border-radius:50%}
.cursor-dot{width:6px;height:6px;background:var(--accent);transform:translate(-50%,-50%)}
.cursor-ring{width:36px;height:36px;border:1.5px solid var(--accent);transform:translate(-50%,-50%);transition:width .25s,height .25s,opacity .25s,background .25s,border-color .25s}
.cursor-ring.hot{width:60px;height:60px;background:var(--accent-glow);border-color:transparent}
body.cursor-on{cursor:none}
body.cursor-on a,body.cursor-on button{cursor:none}
@media (hover:none),(pointer:coarse){.cursor-dot,.cursor-ring{display:none!important}body.cursor-on{cursor:auto}}

/* ===================== REVEAL ===================== */
.reveal{opacity:0;transform:translateY(26px);transition:opacity .9s cubic-bezier(.2,.7,.2,1),transform .9s cubic-bezier(.2,.7,.2,1)}
.reveal.in{opacity:1;transform:none}
.reveal[data-d="1"]{transition-delay:.08s}
.reveal[data-d="2"]{transition-delay:.16s}
.reveal[data-d="3"]{transition-delay:.24s}
.reveal[data-d="4"]{transition-delay:.32s}
.reveal[data-d="5"]{transition-delay:.4s}
@media (prefers-reduced-motion:reduce){.reveal{opacity:1;transform:none;transition:none}}

/* ===================== LOGO MARK (official geometry) ===================== */
.ymark{display:block;overflow:visible}
.ymark .ring{fill:none;stroke:var(--ring);stroke-width:7}
.ymark .core{fill:var(--core)}

/* ===================== FOOTER ===================== */
.foot{background:var(--bg-2);border-top:1px solid var(--line);padding-block:5rem 2.5rem}
.foot-grid{display:grid;grid-template-columns:1.6fr 1fr 1fr 1fr;gap:2.5rem}
.foot-col h4{font-family:'JetBrains Mono',monospace;font-size:.72rem;letter-spacing:.2em;text-transform:uppercase;color:var(--muted);margin-bottom:1.1rem;font-weight:500}
.foot-col a{display:block;color:var(--text-soft);font-size:.96rem;padding:.32rem 0;transition:color .25s}
.foot-col a:hover{color:var(--accent)}
.foot-bottom{display:flex;justify-content:space-between;align-items:center;margin-top:3.5rem;padding-top:1.8rem;border-top:1px solid var(--line);color:var(--muted);font-size:.85rem}
.foot-bottom .mono{font-size:.78rem}

/* ===================== UTILITY ===================== */
.grad-text{background:linear-gradient(105deg,var(--accent) 0%, var(--accent-2) 60%, var(--accent) 100%);-webkit-background-clip:text;background-clip:text;color:transparent}
.center{text-align:center}
.stack-sm>*+*{margin-top:1rem}
.stack>*+*{margin-top:1.6rem}
.row{display:flex;align-items:center;gap:1rem;flex-wrap:wrap}
.grid-tag{font-family:'JetBrains Mono',monospace;font-size:.7rem;letter-spacing:.18em;text-transform:uppercase;color:var(--muted)}
.noise{position:absolute;inset:0;pointer-events:none;opacity:.35;mix-blend-mode:overlay;background-image:url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='160' height='160'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='.9' numOctaves='2'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)' opacity='.5'/%3E%3C/svg%3E")}

/* responsive */
@media (max-width:860px){
  body{font-size:16px}
  .nav-links{display:none}
  .nav-burger{display:grid}
  .mobile-menu{display:flex}
  .foot-grid{grid-template-columns:1fr 1fr;gap:2rem}
  .foot-bottom{flex-direction:column;gap:1rem;text-align:center}
}