/* ===== АО «Сила света» — полярная ночь + северное сияние + свет в оптоволокне ===== */
:root{
  --bg:#05070E; --bg-2:#0A0F1E;
  --panel:#0C1424; --panel-2:#0E1830;
  --aurora:#3FE0C5;      /* бирюзово-зелёный — главный акцент */
  --aurora-2:#7B6CF0;    /* фиолет */
  --blue:#2E7DD8;
  --grad:linear-gradient(120deg,#3FE0C5 0%,#2E7DD8 55%,#7B6CF0 100%);
  --ink:#EAF1FB; --muted:#9FB0C8; --faint:#5E6E88;
  --line:rgba(255,255,255,.08); --line-2:rgba(255,255,255,.14);
  --glow:rgba(63,224,197,.16);
  --wrap:1240px;
}
*{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;scroll-behavior:smooth}
html.has-js{scroll-behavior:auto}
body{
  margin:0;background:var(--bg);color:var(--ink);
  font-family:'Onest',system-ui,sans-serif;font-weight:400;line-height:1.5;
  -webkit-font-smoothing:antialiased;text-rendering:optimizeLegibility;overflow-x:hidden;
}
a{color:inherit;text-decoration:none}
img{max-width:100%;display:block}
.wrap{width:100%;max-width:var(--wrap);margin:0 auto;padding:0 clamp(20px,5vw,64px)}
.display{font-family:'Prata',Georgia,serif;font-weight:400;letter-spacing:-.01em}
.mono{font-family:'Onest',sans-serif;font-weight:500;letter-spacing:.14em;text-transform:uppercase}
::selection{background:rgba(63,224,197,.28);color:#fff}

/* ---- aurora backdrop ---- */
.aurora{position:fixed;inset:-20% -10% 0;z-index:0;pointer-events:none;overflow:hidden;filter:blur(70px)}
.aurora__band{position:absolute;border-radius:50%;opacity:.5;mix-blend-mode:screen;will-change:transform}
.aurora__band--1{width:70vw;height:60vh;left:-10vw;top:-8vh;background:radial-gradient(circle at 50% 50%,var(--aurora) 0%,rgba(63,224,197,0) 68%);animation:drift1 26s ease-in-out infinite alternate}
.aurora__band--2{width:60vw;height:55vh;right:-8vw;top:6vh;background:radial-gradient(circle at 50% 50%,var(--aurora-2) 0%,rgba(123,108,240,0) 66%);opacity:.42;animation:drift2 32s ease-in-out infinite alternate}
.aurora__band--3{width:80vw;height:40vh;left:8vw;top:34vh;background:radial-gradient(circle at 50% 50%,var(--blue) 0%,rgba(46,125,216,0) 70%);opacity:.34;animation:drift3 38s ease-in-out infinite alternate}
@keyframes drift1{from{transform:translate3d(0,0,0) scale(1)}to{transform:translate3d(6vw,4vh,0) scale(1.14)}}
@keyframes drift2{from{transform:translate3d(0,0,0) scale(1.05)}to{transform:translate3d(-5vw,5vh,0) scale(.92)}}
@keyframes drift3{from{transform:translate3d(0,0,0) scale(1)}to{transform:translate3d(4vw,-4vh,0) scale(1.1)}}

/* grain */
.grain{position:fixed;inset:0;z-index:2;pointer-events:none;opacity:.045;mix-blend-mode:overlay;
  background-image:url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='180' height='180'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.85' numOctaves='2' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)'/%3E%3C/svg%3E")}

/* ---- optical cable: light runs down as you scroll ---- */
.cable{position:fixed;left:clamp(12px,3.2vw,38px);top:0;bottom:0;width:2px;z-index:3;pointer-events:none;
  background:linear-gradient(180deg,rgba(63,224,197,.04),rgba(63,224,197,.13) 12%,rgba(63,224,197,.13) 88%,rgba(63,224,197,.04));
  border-radius:2px}
.cable__fill{position:absolute;left:0;top:0;width:100%;height:0;border-radius:2px;
  background:linear-gradient(180deg,rgba(63,224,197,0),rgba(63,224,197,.5));
  box-shadow:0 0 6px rgba(63,224,197,.35)}
.cable__dot{position:absolute;left:50%;top:0;width:9px;height:9px;border-radius:50%;transform:translate(-50%,-50%);
  background:#EAFFF9;box-shadow:0 0 10px 2px var(--aurora),0 0 24px 7px rgba(63,224,197,.55);will-change:top}
@media (max-width:520px){.cable{display:none}}

/* scrollbar */
::-webkit-scrollbar{width:10px}
::-webkit-scrollbar-track{background:var(--bg)}
::-webkit-scrollbar-thumb{background:#16233c;border-radius:20px;border:3px solid var(--bg)}
::-webkit-scrollbar-thumb:hover{background:#20314f}

/* ---- shared bits ---- */
.eyebrow{color:var(--aurora);font-family:'Onest';font-weight:500;letter-spacing:.16em;text-transform:uppercase;font-size:13px;margin:0}
.sec-title{font-size:clamp(2rem,4.6vw,3.4rem);line-height:1.05;margin:16px 0 0}
.sec-lead{color:var(--muted);font-size:1.1rem;line-height:1.6;max-width:56ch;margin:18px 0 0}
.section{position:relative;z-index:1;padding:clamp(72px,12vh,150px) 0}
.btn{font:inherit;cursor:pointer;border:none;border-radius:999px;transition:transform .25s,box-shadow .3s,border-color .25s,background .25s}
.btn--cta{padding:9px 20px;background:var(--grad);color:#04121a;font-weight:600;box-shadow:0 6px 22px rgba(63,224,197,.22)}
.btn--cta:hover{transform:translateY(-1px);box-shadow:0 10px 30px rgba(63,224,197,.34)}
.btn--line{margin-top:26px;padding:12px 22px;background:transparent;color:var(--ink);border:1px solid var(--line-2);font-weight:500}
.btn--line:hover{border-color:var(--aurora);box-shadow:0 0 0 3px var(--glow)}

/* ---- header ---- */
.site-header{position:fixed;top:0;left:0;right:0;z-index:50;display:flex;align-items:center;justify-content:space-between;
  padding:14px clamp(20px,5vw,64px);transition:background .4s ease,border-color .4s ease,backdrop-filter .4s}
.site-header.solid{background:rgba(5,7,14,.72);backdrop-filter:blur(14px) saturate(1.2);-webkit-backdrop-filter:blur(14px) saturate(1.2);border-bottom:1px solid var(--line)}
.brand{display:inline-flex;align-items:center;gap:10px}
.brand__spark{width:12px;height:12px;border-radius:50%;background:var(--aurora);box-shadow:0 0 12px 2px var(--aurora),0 0 26px 6px rgba(63,224,197,.5);flex:none}
.brand__name{font-family:'Onest';font-weight:700;letter-spacing:.14em;font-size:16px;color:var(--ink)}
.nav{display:flex;align-items:center;gap:clamp(14px,2vw,30px)}
.nav a{color:var(--muted);font-size:13px;letter-spacing:.04em;transition:color .25s}
.nav a:hover{color:var(--ink)}

/* ---- hero ---- */
.hero{position:relative;min-height:100svh;display:flex;align-items:center;z-index:1;overflow:hidden}
.hero__glow{position:absolute;left:50%;top:44%;width:min(90vw,900px);height:min(90vw,900px);transform:translate(-50%,-50%);
  background:radial-gradient(circle,var(--glow) 0%,rgba(63,224,197,0) 62%);pointer-events:none}
.hero__inner{position:relative}
.hero__title{font-size:clamp(2.8rem,8vw,6.6rem);line-height:1.02;letter-spacing:-.02em;margin:22px 0 0;color:var(--ink)}
.hero__lead{color:var(--muted);font-size:clamp(1.05rem,1.8vw,1.35rem);line-height:1.6;max-width:44ch;margin:26px 0 0}
.hero__hint{display:flex;align-items:center;gap:14px;margin-top:52px}
.hero__hint .mono{font-size:12px;color:var(--faint);letter-spacing:.14em}
.hero__line{width:46px;height:1px;background:linear-gradient(90deg,var(--aurora),transparent);
  position:relative;overflow:visible}
.hero__line::after{content:"";position:absolute;top:-1px;left:0;width:10px;height:3px;border-radius:3px;background:var(--aurora);
  box-shadow:0 0 8px 1px var(--aurora);animation:fiberPulse 2.6s linear infinite}
@keyframes fiberPulse{0%{left:-10px;opacity:0}12%{opacity:1}88%{opacity:1}100%{left:46px;opacity:0}}

/* ---- about cards ---- */
.about .cards{display:grid;gap:16px;grid-template-columns:repeat(auto-fit,minmax(240px,1fr));margin-top:44px}
.card{position:relative;background:var(--panel);border:1px solid var(--line);border-radius:18px;padding:26px;overflow:hidden;
  transition:transform .4s cubic-bezier(.16,1,.3,1),border-color .4s,box-shadow .4s}
.card::before{content:"";position:absolute;inset:0;border-radius:18px;padding:1px;background:var(--grad);opacity:0;
  -webkit-mask:linear-gradient(#000 0 0) content-box,linear-gradient(#000 0 0);-webkit-mask-composite:xor;mask-composite:exclude;transition:opacity .35s}
.card:hover{transform:translateY(-4px);border-color:var(--line-2);box-shadow:0 18px 40px rgba(0,0,0,.4)}
.card:hover::before{opacity:.6}
.card__k{color:var(--aurora);font-size:13px}
.card h3{font-size:1.2rem;margin:12px 0 8px;letter-spacing:-.01em}
.card p{color:var(--muted);font-size:.98rem;line-height:1.55;margin:0}

/* ---- DWDM schematic ---- */
.dwdm__fig{margin:44px 0 0;background:var(--panel);border:1px solid var(--line);border-radius:22px;
  padding:clamp(20px,3.4vw,40px);position:relative;overflow:hidden}
.dwdm__fig::after{content:"";position:absolute;left:40%;top:-40%;width:340px;height:340px;border-radius:50%;
  background:radial-gradient(circle,var(--glow) 0%,rgba(63,224,197,0) 68%);pointer-events:none}
.dwdm__svg{position:relative;width:100%;height:auto;display:block;overflow:visible}
.dwdm__svg circle{filter:drop-shadow(0 0 4px rgba(234,255,249,.35))}
.dwdm__fiber{filter:drop-shadow(0 0 5px rgba(63,224,197,.45))}
.dwdm__flow{filter:drop-shadow(0 0 7px #EAFFF9);animation:dwdmFlow 1.6s linear infinite}
@keyframes dwdmFlow{from{stroke-dashoffset:0}to{stroke-dashoffset:-48}}

/* ---- requisites ---- */
.reqcard{margin-top:40px;background:var(--panel);border:1px solid var(--line);border-radius:22px;padding:clamp(24px,4vw,44px);position:relative;overflow:hidden}
.reqcard::after{content:"";position:absolute;right:-120px;top:-120px;width:340px;height:340px;border-radius:50%;
  background:radial-gradient(circle,var(--glow) 0%,rgba(63,224,197,0) 68%);pointer-events:none}
.reqcard__grid{display:grid;gap:20px;grid-template-columns:repeat(auto-fit,minmax(200px,1fr));position:relative}
.req__k{display:block;color:var(--faint);font-size:11px;margin-bottom:8px}
.req__v{font-size:clamp(1.7rem,3.4vw,2.6rem);color:var(--ink);letter-spacing:.01em}
.reqcard__foot{display:grid;gap:20px;grid-template-columns:repeat(auto-fit,minmax(240px,1fr));margin-top:30px;padding-top:26px;border-top:1px solid var(--line);position:relative}
.reqcard__foot p{margin:6px 0 0;font-size:1.02rem;color:var(--ink)}

/* ---- contacts ---- */
.contacts{min-height:82vh;display:flex;align-items:center}
.contacts__inner{display:flex;flex-direction:column}
.email{align-self:flex-start;background:none;border:none;padding:0;margin:30px 0 0;cursor:pointer;text-align:left;
  font-family:'Onest';font-weight:700;letter-spacing:-.02em;font-size:clamp(1.8rem,6vw,4.4rem);
  background-image:var(--grad);-webkit-background-clip:text;background-clip:text;color:transparent;-webkit-text-fill-color:transparent}
.email__hint{margin-top:14px;font-size:12px;color:var(--faint)}
.contacts__place{margin-top:40px;font-size:12px;color:var(--muted)}

/* ---- footer ---- */
.site-footer{position:relative;z-index:1;display:flex;flex-wrap:wrap;gap:16px;align-items:center;justify-content:space-between;
  padding:40px clamp(20px,5vw,64px);border-top:1px solid var(--line);background:var(--bg)}
.footer__legal{font-size:12px;color:var(--faint);letter-spacing:.02em;text-transform:none}
.footer__mail{font-size:12px;color:var(--aurora);text-transform:none;letter-spacing:.02em}

/* ---- reveal ---- */
[data-rise]{opacity:0;transform:translateY(26px);transition:opacity .9s cubic-bezier(.16,1,.3,1),transform .9s cubic-bezier(.16,1,.3,1)}
[data-rise].is-visible{opacity:1;transform:none}

/* ---- toast ---- */
.toast{position:fixed;left:50%;bottom:28px;transform:translateX(-50%);z-index:100;
  padding:10px 18px;border-radius:999px;background:var(--panel-2);color:var(--aurora);
  border:1px solid var(--line);font-size:13px;letter-spacing:.06em;box-shadow:0 10px 30px rgba(0,0,0,.4);
  opacity:0;pointer-events:none;transition:opacity .25s}
.toast.show{opacity:1}

/* ---- responsive ---- */
@media (max-width:760px){
  .nav a{display:none}
  .hero__title br{display:none}
}

/* ---- reduced motion ---- */
@media (prefers-reduced-motion:reduce){
  *{animation:none !important;scroll-behavior:auto !important}
  [data-rise]{opacity:1 !important;transform:none !important;transition:none !important}
  .aurora__band{animation:none !important}
  .hero__line::after{display:none}
}
html.reduce [data-rise]{opacity:1;transform:none}