/* =========================================================
   BirroTech — Design System
========================================================= */
:root{
  --bg: #05070d;
  --bg-alt: #080b14;
  --surface: #0d1220;
  --surface-2: #10182b;
  --border: rgba(255,255,255,.08);
  --text: #eef2ff;
  --text-dim: #9aa4c2;
  --text-faint: #6b7394;

  --blue-1: #3ec9ff;
  --blue-2: #2596ff;
  --blue-3: #0a5fd9;
  --blue-deep: #062a6b;
  --white: #f5f7ff;

  --grad-brand: linear-gradient(120deg, var(--blue-1), var(--blue-2) 55%, var(--blue-3));
  --grad-text: linear-gradient(120deg, #7fe1ff, #3d9dff 60%, #1a6bff);

  --radius: 18px;
  --radius-sm: 10px;
  --shadow-glow: 0 0 60px rgba(37,150,255,.25);
  --ease: cubic-bezier(.16,.84,.44,1);
}

*,*::before,*::after{ box-sizing: border-box; }
html{ scroll-behavior: smooth; }
body{
  margin:0;
  background: var(--bg);
  color: var(--text);
  font-family: 'Inter', system-ui, sans-serif;
  line-height: 1.6;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}
h1,h2,h3,h4{
  font-family: 'Space Grotesk', 'Inter', sans-serif;
  margin: 0 0 .5em;
  line-height: 1.15;
  letter-spacing: -.02em;
  color: var(--white);
}
p{ margin: 0 0 1em; color: var(--text-dim); }
a{ color: inherit; text-decoration: none; }
img{ max-width: 100%; display: block; }
ul{ list-style: none; margin:0; padding:0; }
button{ font-family: inherit; cursor: pointer; }

.container{
  width: min(1180px, 92%);
  margin: 0 auto;
}

/* background fx */
.bg-grid{
  position: fixed; inset:0; z-index:-2;
  background-image:
    linear-gradient(rgba(255,255,255,.035) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255,255,255,.035) 1px, transparent 1px);
  background-size: 44px 44px;
  mask-image: radial-gradient(ellipse 80% 60% at 50% 0%, #000 30%, transparent 90%);
}
.bg-glow{
  position: fixed; z-index:-1; inset:0;
  background:
    radial-gradient(600px 400px at 15% 10%, rgba(37,150,255,.18), transparent 60%),
    radial-gradient(700px 500px at 85% 25%, rgba(62,201,255,.12), transparent 60%),
    radial-gradient(600px 600px at 50% 90%, rgba(10,95,217,.15), transparent 60%);
}

/* reveal animation */
[data-reveal]{
  opacity: 0;
  transform: translateY(28px);
  transition: opacity .8s var(--ease), transform .8s var(--ease);
}
[data-reveal].is-visible{
  opacity: 1;
  transform: translateY(0);
}

/* =========== HEADER =========== */
.header{
  position: fixed; top:0; left:0; right:0; z-index: 100;
  padding: 18px 0;
  transition: background .3s ease, backdrop-filter .3s ease, box-shadow .3s ease, padding .3s ease;
}
.header.is-scrolled{
  padding: 10px 0;
  background: rgba(5,7,13,.75);
  backdrop-filter: blur(14px) saturate(140%);
  box-shadow: 0 1px 0 var(--border), 0 10px 30px rgba(0,0,0,.35);
}
.header__inner{
  display:flex; align-items:center; justify-content: space-between;
}
.brand{ display:flex; align-items:center; gap: 12px; }
.brand__mark{ height: 52px; width:auto; }
.brand__name{
  font-family:'Space Grotesk',sans-serif;
  font-size: 1.35rem; font-weight: 700;
  color: var(--white);
  letter-spacing: -.01em;
}

.nav{ display:flex; align-items:center; gap: 34px; }
.nav a{
  font-size: .95rem; font-weight: 500; color: var(--text-dim);
  position: relative; padding: 4px 0;
  transition: color .25s ease;
}
.nav a::after{
  content:''; position:absolute; left:0; bottom:-2px; width:0; height:2px;
  background: var(--grad-brand); transition: width .25s ease;
}
.nav a:hover{ color: var(--white); }
.nav a:hover::after{ width: 100%; }
.nav__cta{
  padding: 10px 20px !important;
  background: var(--grad-brand);
  color: #04101f !important;
  font-weight: 600 !important;
  border-radius: 999px;
}
.nav__cta::after{ display:none; }
.nav__cta:hover{ filter: brightness(1.1); color: #04101f !important; }

.burger{
  display:none; flex-direction:column; gap:5px;
  background: none; border:none; padding: 8px;
}
.burger span{
  width: 24px; height: 2px; background: var(--white); border-radius: 2px;
  transition: transform .3s ease, opacity .3s ease;
}

/* =========== HERO =========== */
.hero{
  position: relative;
  padding: 190px 0 100px;
  min-height: 100vh;
  display:flex; align-items:center;
}
.hero__inner{
  display:grid;
  grid-template-columns: 1.1fr .9fr;
  gap: 40px;
  align-items:center;
}
.tag{
  display:inline-flex; align-items:center; gap:8px;
  padding: 7px 16px;
  border: 1px solid var(--border);
  border-radius: 999px;
  font-size: .8rem;
  color: var(--blue-1);
  background: rgba(37,150,255,.08);
  margin-bottom: 22px;
}
.tag__dot{
  width:7px; height:7px; border-radius:50%;
  background: var(--blue-1);
  box-shadow: 0 0 10px var(--blue-1);
  animation: pulse 1.8s infinite;
}
@keyframes pulse{
  0%,100%{ opacity:1; } 50%{ opacity:.35; }
}
.hero h1{
  font-size: clamp(2.2rem, 4.6vw, 3.6rem);
  max-width: 14ch;
}
.text-grad{
  background: var(--grad-text);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.hero__lead{
  font-size: 1.08rem;
  max-width: 46ch;
  margin-bottom: 34px;
}
.hero__actions{ display:flex; gap:16px; flex-wrap:wrap; margin-bottom: 56px; }

.btn{
  display:inline-flex; align-items:center; justify-content:center;
  padding: 15px 30px;
  border-radius: 999px;
  font-weight: 600;
  font-size: .95rem;
  border: 1px solid transparent;
  transition: transform .25s var(--ease), box-shadow .25s ease, background .25s ease, border-color .25s ease;
}
.btn--primary{
  background: var(--grad-brand);
  color: #041020;
  box-shadow: 0 10px 30px -8px rgba(37,150,255,.6);
}
.btn--primary:hover{ transform: translateY(-3px); box-shadow: 0 16px 36px -8px rgba(37,150,255,.75); }
.btn--ghost{
  color: var(--white);
  border-color: var(--border);
  background: rgba(255,255,255,.02);
}
.btn--ghost:hover{ border-color: var(--blue-2); background: rgba(37,150,255,.08); transform: translateY(-3px); }
.btn--lg{ padding: 17px 38px; font-size: 1rem; }
.btn--block{ width: 100%; }

.hero__stats{ display:flex; gap: 40px; flex-wrap: wrap; }
.stat strong{
  display:block; font-family:'Space Grotesk',sans-serif;
  font-size: 1.9rem; color: var(--white);
}
.stat span{ font-size: .85rem; color: var(--text-faint); }

/* hero visual — dev card */
.hero__visual{ display:flex; align-items:center; justify-content:center; }
@keyframes float{
  0%,100%{ transform: translateY(0); }
  50%{ transform: translateY(-14px); }
}

.devcard{
  position: relative;
  width: min(460px, 100%);
  transform: perspective(1200px) rotateY(-8deg) rotateX(3deg);
  animation: float 6s ease-in-out infinite;
}
.devcard__glow{
  position:absolute; inset: -10%;
  background: radial-gradient(circle, rgba(37,150,255,.35), transparent 65%);
  filter: blur(30px);
  z-index: -1;
}
.devcard__window{
  background: linear-gradient(180deg, #0c1220, #080c16);
  border: 1px solid var(--border);
  border-radius: 16px;
  overflow: hidden;
  box-shadow: 0 30px 70px -20px rgba(0,0,0,.7), 0 0 0 1px rgba(255,255,255,.02);
}
.devcard__bar{
  display:flex; align-items:center; gap: 8px;
  padding: 14px 16px;
  background: rgba(255,255,255,.03);
  border-bottom: 1px solid var(--border);
}
.dot{ width:11px; height:11px; border-radius:50%; }
.dot--red{ background:#ff5f57; }
.dot--yellow{ background:#febc2e; }
.dot--green{ background:#28c840; }
.devcard__title{
  margin-left: 8px;
  font-size: .78rem;
  color: var(--text-faint);
  font-family: 'Space Grotesk', sans-serif;
}
.devcard__code{
  margin: 0;
  padding: 22px 24px;
  font-family: 'Fira Code', 'Consolas', monospace;
  font-size: .85rem;
  line-height: 1.85;
  color: var(--text-dim);
  overflow-x: auto;
}
.devcard__code .c-kw{ color: #7fa8ff; }
.devcard__code .c-cl{ color: var(--blue-1); }
.devcard__code .c-fn{ color: #9fe6c5; }
.devcard__code .c-str{ color: #ffcb6b; }
.devcard__code .c-com{ color: var(--text-faint); font-style: italic; }

.devcard__chip{
  position:absolute;
  display:flex; align-items:center; gap:6px;
  padding: 10px 16px;
  border-radius: 999px;
  background: var(--surface-2);
  border: 1px solid var(--border);
  font-size: .8rem;
  font-weight: 500;
  color: var(--text);
  box-shadow: 0 12px 24px rgba(0,0,0,.4);
  animation: float 5s ease-in-out infinite;
  white-space: nowrap;
}
.devcard__chip--1{ top: -6%; right: -8%; animation-delay: .2s; }
.devcard__chip--2{ bottom: 14%; left: -12%; animation-delay: 1s; }
.devcard__chip--3{ bottom: -6%; right: 6%; animation-delay: 1.6s; }

.scroll-cue{
  position:absolute; bottom: 26px; left:50%; transform: translateX(-50%);
  display:flex; align-items:center; gap:10px;
  font-size: .75rem; letter-spacing:.08em; text-transform: uppercase;
  color: var(--text-faint);
}
.scroll-cue span{
  width: 1px; height: 26px; background: linear-gradient(var(--blue-1), transparent);
  position:relative; overflow:hidden;
}
.scroll-cue span::after{
  content:''; position:absolute; top:-30px; left:0; width:100%; height:30px;
  background: var(--blue-1);
  animation: scrolldown 1.8s ease-in-out infinite;
}
@keyframes scrolldown{
  to{ top: 60px; }
}

/* =========== TRUST MARQUEE =========== */
.trust{ padding: 50px 0; border-top: 1px solid var(--border); border-bottom: 1px solid var(--border); }
.trust__inner p{
  text-align:center; font-size: .8rem; letter-spacing: .1em; text-transform: uppercase;
  color: var(--text-faint); margin-bottom: 24px;
}
.trust__marquee{ overflow: hidden; mask-image: linear-gradient(90deg, transparent, #000 10%, #000 90%, transparent); }
.trust__track{
  display:flex; gap: 50px; width: max-content;
  animation: marquee 26s linear infinite;
}
.trust__track span{
  font-family:'Space Grotesk',sans-serif;
  font-size: 1.15rem; color: var(--text-faint);
  white-space: nowrap;
}
@keyframes marquee{
  from{ transform: translateX(0); }
  to{ transform: translateX(-50%); }
}

/* =========== SECTIONS =========== */
.section{ padding: 120px 0; }
.section--alt{ background: linear-gradient(180deg, transparent, rgba(255,255,255,.015), transparent); }

.section__head{ max-width: 640px; margin: 0 auto 60px; text-align:center; }
.section__head--left{ margin: 0 0 40px; text-align:left; }
.eyebrow{
  display:inline-block; font-size: .8rem; font-weight:600;
  letter-spacing:.08em; text-transform: uppercase;
  color: var(--blue-1); margin-bottom: 14px;
}
.section__head h2{ font-size: clamp(1.7rem, 3vw, 2.4rem); }
.section__head p{ font-size: 1.05rem; }

.grid{ display:grid; gap: 26px; }
.grid--3{ grid-template-columns: repeat(3, 1fr); }

.card{
  background: linear-gradient(180deg, var(--surface), var(--surface-2));
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 34px 28px;
  transition: transform .35s var(--ease), border-color .35s ease, box-shadow .35s ease;
  position: relative;
  overflow: hidden;
}
.card::before{
  content:''; position:absolute; inset:0; opacity:0;
  background: radial-gradient(240px circle at 30% 0%, rgba(37,150,255,.14), transparent 70%);
  transition: opacity .35s ease;
}
.card:hover{ transform: translateY(-8px); border-color: rgba(37,150,255,.35); box-shadow: var(--shadow-glow); }
.card:hover::before{ opacity:1; }
.card__icon{
  width: 56px; height: 56px; display:flex; align-items:center; justify-content:center;
  font-size: 1.5rem; border-radius: 14px; margin-bottom: 22px;
  background: rgba(37,150,255,.1); border: 1px solid rgba(37,150,255,.2);
}
.card h3{ font-size: 1.2rem; margin-bottom: 10px; }
.card p{ font-size: .95rem; margin: 0; }

/* steps */
.steps{
  display:grid; grid-template-columns: repeat(4,1fr); gap: 24px;
  position: relative;
}
.step{
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 30px 24px;
  transition: transform .3s var(--ease), border-color .3s ease;
}
.step:hover{ transform: translateY(-6px); border-color: rgba(37,150,255,.3); }
.step__num{
  font-family:'Space Grotesk',sans-serif;
  font-size: 2.2rem; font-weight:700;
  background: var(--grad-text);
  -webkit-background-clip:text; background-clip:text; color:transparent;
  display:block; margin-bottom: 14px;
}
.step h3{ font-size: 1.1rem; margin-bottom: 8px; }
.step p{ font-size: .92rem; margin:0; }

/* stack grid */
.stackgrid{
  display:grid; grid-template-columns: repeat(4, 1fr); gap: 18px;
}
.stackitem{
  text-align:center; padding: 22px 12px;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--surface);
  font-family:'Space Grotesk',sans-serif; font-weight:600;
  color: var(--text-dim);
  transition: all .3s ease;
}
.stackitem:hover{
  color: var(--white);
  border-color: var(--blue-2);
  background: rgba(37,150,255,.08);
  transform: translateY(-4px);
}

/* about */
.about{ display:grid; grid-template-columns: .8fr 1.2fr; gap: 60px; align-items:center; }
.about__card{
  background: radial-gradient(circle at 50% 30%, rgba(37,150,255,.15), transparent 70%), var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 50px;
  display:flex; align-items:center; justify-content:center;
}
.about__content .eyebrow{ margin-bottom: 14px; }
.about__content h2{ font-size: clamp(1.6rem, 3vw, 2.2rem); }
.checklist{ margin-top: 24px; display:flex; flex-direction:column; gap: 14px; }
.checklist li{
  display:flex; align-items:center; gap: 12px;
  color: var(--text); font-size: .98rem;
}
.checklist li::before{
  content:'✓'; width: 26px; height:26px; flex:none;
  display:flex; align-items:center; justify-content:center;
  border-radius:50%; background: var(--grad-brand); color:#04101f; font-size:.8rem; font-weight:700;
}

/* CTA */
.cta{
  padding: 90px 0;
  position: relative;
  overflow: hidden;
}
.cta::before{
  content:''; position:absolute; inset:0;
  background: linear-gradient(120deg, rgba(37,150,255,.12), rgba(10,95,217,.05));
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
}
.cta__inner{ position:relative; text-align:center; max-width: 620px; margin:0 auto; }
.cta h2{ font-size: clamp(1.7rem,3.4vw,2.4rem); }

/* contact */
.contact{ display:grid; grid-template-columns: .9fr 1.1fr; gap: 60px; }
.contact__info{ display:flex; flex-direction:column; gap: 16px; margin-top: 30px; }
.contact__item{
  display:flex; align-items:center; gap: 12px;
  padding: 14px 18px;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--surface);
  color: var(--text-dim);
  font-size: .95rem;
  transition: border-color .25s ease, color .25s ease;
}
a.contact__item:hover{ border-color: var(--blue-2); color: var(--white); }
.contact__item span{ font-size: 1.1rem; }

.form{
  display:flex; flex-direction:column; gap: 16px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 34px;
}
.form__row{ display:grid; grid-template-columns: 1fr 1fr; gap: 16px; }
.form input, .form textarea{
  width:100%;
  background: var(--bg-alt);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 14px 16px;
  color: var(--text);
  font-family: inherit;
  font-size: .95rem;
  resize: vertical;
  transition: border-color .25s ease, box-shadow .25s ease;
}
.form input::placeholder, .form textarea::placeholder{ color: var(--text-faint); }
.form input:focus, .form textarea:focus{
  outline: none;
  border-color: var(--blue-2);
  box-shadow: 0 0 0 3px rgba(37,150,255,.15);
}

/* footer */
.footer{ border-top: 1px solid var(--border); padding: 40px 0; }
.footer__inner{
  display:flex; align-items:center; justify-content:space-between; flex-wrap:wrap; gap: 20px;
}
.footer__inner .brand__mark{ height: 38px; }
.footer__inner .brand__name{ font-size: 1.1rem; }
.footer p{ margin:0; font-size: .85rem; color: var(--text-faint); }
.footer__social{ display:flex; gap: 12px; }
.footer__social a{
  width: 36px; height:36px; display:flex; align-items:center; justify-content:center;
  border: 1px solid var(--border); border-radius: 50%;
  font-size: .75rem; color: var(--text-dim);
  transition: all .25s ease;
}
.footer__social a:hover{ border-color: var(--blue-2); color: var(--white); background: rgba(37,150,255,.08); }

/* floating action button */
.fab{
  position: fixed; bottom: 26px; right: 26px; z-index: 90;
  width: 58px; height: 58px; border-radius: 50%;
  background: var(--grad-brand);
  display:flex; align-items:center; justify-content:center;
  font-size: 1.4rem;
  box-shadow: 0 12px 30px -6px rgba(37,150,255,.6);
  animation: float 4s ease-in-out infinite;
  transition: transform .25s ease;
}
.fab:hover{ transform: scale(1.08); }

/* =========== RESPONSIVE =========== */
@media (max-width: 980px){
  .hero__inner{ grid-template-columns: 1fr; text-align:center; }
  .hero__lead{ margin-inline:auto; }
  .hero__actions{ justify-content:center; }
  .hero__stats{ justify-content:center; }
  .hero__visual{ order:-1; margin-bottom: 20px; }
  .devcard{ width: min(380px, 90%); transform: none; }

  .grid--3{ grid-template-columns: repeat(2,1fr); }
  .steps{ grid-template-columns: repeat(2,1fr); }
  .stackgrid{ grid-template-columns: repeat(3,1fr); }
  .about, .contact{ grid-template-columns: 1fr; }
  .about__visual{ order: -1; }

  .devcard__chip{ font-size: .72rem; padding: 8px 12px; }
  .devcard__chip--1{ right: 0; }
  .devcard__chip--2{ left: 0; }
}

@media (max-width: 720px){
  .nav{
    position: fixed; top: 74px; left: 16px; right: 16px;
    background: rgba(8,11,20,.97);
    backdrop-filter: blur(20px);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    flex-direction: column; align-items: stretch;
    gap: 4px; padding: 14px;
    transform: translateY(-16px); opacity:0; visibility:hidden;
    transition: all .3s var(--ease);
  }
  .nav.is-open{ transform: translateY(0); opacity:1; visibility:visible; }
  .nav a{ padding: 12px 10px; border-radius: 10px; }
  .nav a:hover{ background: rgba(255,255,255,.04); }
  .nav__cta{ text-align:center; margin-top: 6px; }
  .burger{ display:flex; }

  .grid--3{ grid-template-columns: 1fr; }
  .steps{ grid-template-columns: 1fr; }
  .stackgrid{ grid-template-columns: repeat(2,1fr); }
  .form__row{ grid-template-columns: 1fr; }
  .footer__inner{ justify-content:center; text-align:center; }
}