:root{
  --bg: hsl(0 0% 100%);
  --surface: hsl(0 0% 100%);
  --text: hsl(220 15% 10%);
  --muted: hsl(220 10% 45%);
  --border: hsl(220 16% 90%);
  --brand: hsl(210 90% 40%);
  --brand-2: hsl(210 70% 55%);
  --radius: 14px;
  --shadow: 0 8px 24px rgba(0,0,0,0.06);
}

*{box-sizing:border-box}
body{margin:0;font:16px/1.65 ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, Helvetica, Arial;color:var(--text);background:var(--bg)}

.container{max-width:1100px;margin-inline:auto;padding:24px}

/* Header: logo + nav + CTA, with motion */
.site-header{
  position:sticky;top:0;z-index:40;
  background:rgba(255,255,255,.85);
  backdrop-filter:saturate(150%) blur(8px);
  border-bottom:1px solid var(--border);
  transition: box-shadow .25s ease, background-color .25s ease, transform .3s ease, height .2s ease;
}
.site-header.scrolled{ box-shadow: 0 8px 24px rgba(0,0,0,0.06); }

.head-inner{display:flex;align-items:center;justify-content:space-between;gap:16px}
.brand{display:inline-flex;align-items:center;gap:10px;text-decoration:none;color:var(--text);font-weight:700}
.brand .dot{width:10px;height:10px;border-radius:50%;background:linear-gradient(135deg,var(--brand),var(--brand-2))}
.nav{display:flex;gap:18px}
.nav a{color:var(--muted);text-decoration:none;position:relative;overflow:hidden}
.nav a:hover{color:var(--text)}
/* nav underline sweep */
.nav a::after{
  content:"";position:absolute;left:0;bottom:-2px;height:2px;width:100%;
  background:linear-gradient(90deg,var(--brand),var(--brand-2));
  transform:translateX(-101%);transition:transform .35s ease;
}
.nav a:hover::after{ transform:translateX(0); }

.nav a.active{ color: var(--text); }
.nav a.active::after{ transform: translateX(0); }
.btn{
  appearance:none;border:1px solid color-mix(in oklab,var(--brand) 30%, var(--border));
  background:linear-gradient(135deg,var(--brand),var(--brand-2));
  color:#fff;padding:10px 14px;border-radius:12px;text-decoration:none;font-weight:600;
  box-shadow:0 6px 18px rgba(0,0,0,.08);cursor:pointer;
  transition: transform .15s ease, filter .2s ease, box-shadow .25s ease;
}
.btn:hover{filter:brightness(.95);transform:translateY(-1px)}
.btn:active{transform:translateY(0)}
.btn--small{padding:8px 12px}
.btn--ghost{background:#fff;color:var(--brand);border:1px solid var(--border)}

/* Hero split */
.hero{display:grid;grid-template-columns:1.1fr .9fr;gap:24px;align-items:center;padding-top:28px}
.hero-text h1{margin:0 0 6px;font-size:clamp(28px,4vw,44px);line-height:1.15}
.lead{color:var(--muted);max-width:60ch}
.cta-row{display:flex;gap:12px;flex-wrap:wrap}
.hero-visual{padding:0;overflow:hidden}
.hero-visual img{display:block;width:100%;height:auto;border-radius:var(--radius);transition:transform .2s ease}

/* Sections */
.section{padding-block:36px;border-top:1px solid var(--border)}
.section:first-of-type{border-top:0}
.section-head h2{margin:0 0 6px;font-size:clamp(22px,3vw,30px)}
.section-head p{margin:0;color:var(--muted)}

/* Cards & grids */
.card{
  background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);
  box-shadow:var(--shadow);padding:18px;
  transition: transform .25s ease, box-shadow .25s ease, border-color .25s ease;
}
.card:hover{
  transform:translateY(-4px);
  box-shadow:0 12px 28px rgba(0,0,0,.08);
  border-color: color-mix(in oklab, var(--brand) 18%, var(--border));
}
.card-title{margin:0 0 6px;font-size:18px}
.list{margin:8px 0 0;padding-left:18px;color:var(--muted)}

.grid{display:grid;gap:18px}
.grid--3{grid-template-columns:repeat(3,1fr)}
.grid--4{grid-template-columns:repeat(4,1fr)}
.cards-grid .project img{
  display:block;width:100%;height:auto;border-bottom:1px solid var(--border);
  border-top-left-radius:var(--radius);border-top-right-radius:var(--radius);
  transition:transform .5s ease;
}
.project:hover img{ transform:scale(1.03) }
.project-body{padding-top:10px}
.center{display:flex;justify-content:center;margin-top:16px}

/* Reveal-on-scroll (stagger ready) */
@media (prefers-reduced-motion: no-preference){
  [data-animate]{
    opacity:0; transform:translateY(14px);
    transition:opacity .6s ease, transform .6s ease;
    transition-delay: calc(var(--stagger, 0) * 60ms);
    will-change: opacity, transform;
  }
  [data-animate].in-view{ opacity:1; transform:translateY(0); }
}

/* Contact */
.contact .contact-grid{display:grid;grid-template-columns:1.2fr .8fr;gap:18px}
.form{display:grid;gap:10px}
.form label{display:flex;flex-direction:column;gap:6px;color:var(--muted)}
.form input,.form textarea{background:#fff;border:1px solid var(--border);border-radius:10px;padding:10px 12px}
.form input:focus,.form textarea:focus{outline:3px solid color-mix(in oklab,var(--brand) 25%, transparent)}

/* Footer */
.site-footer{border-top:1px solid var(--border);background:#fff;margin-top:28px}
.foot-grid{display:grid;gap:18px;grid-template-columns:2fr 1fr 1fr;align-items:start;padding-block:20px}
.foot-col h4{margin:0 0 8px}
.link{color:var(--muted);text-decoration:none}
.link:hover{color:var(--text)}
.muted{color:var(--muted)}
.small{font-size:12px}

/* Accessibility focus */
:focus-visible{
  outline:3px solid color-mix(in oklab,var(--brand) 40%, transparent);
  outline-offset:2px;
}

/* Responsive */
@media (max-width: 980px){
  .hero{grid-template-columns:1fr}
  .grid--3,.grid--4{grid-template-columns:1fr}
  .contact .contact-grid{grid-template-columns:1fr}
}

/* Base tweaks for smaller screens */
:root{
  --container-pad: 20px;
}
.container{ padding: var(--container-pad); }

/* Make taps comfy */
a, button { -webkit-tap-highlight-color: transparent; }
.nav a, .nav-mobile-link, .btn { padding-block: 10px; }

/* Hide desktop nav on small screens; show hamburger */
.hamburger{ display:none; background:none; border:0; width:42px; height:38px; border-radius:10px; position:relative; cursor:pointer; }
.hamburger:focus-visible{ outline:3px solid color-mix(in oklab, var(--brand) 30%, transparent); }
.hamburger-bar{ position:absolute; left:10px; right:10px; height:2px; background:var(--text); border-radius:2px; transition:transform .25s ease, opacity .2s ease, top .25s ease; }
.hamburger-bar:nth-child(1){ top:12px; }
.hamburger-bar:nth-child(2){ top:18px; }
.hamburger-bar:nth-child(3){ top:24px; }
/* active state (set via [data-open]) */
.hamburger[data-open="true"] .hamburger-bar:nth-child(1){ top:18px; transform:rotate(45deg); }
.hamburger[data-open="true"] .hamburger-bar:nth-child(2){ opacity:0; }
.hamburger[data-open="true"] .hamburger-bar:nth-child(3){ top:18px; transform:rotate(-45deg); }

/* Mobile slide-down panel */
.nav-mobile{ position:relative; border-top:1px solid var(--border); background:#fff; }
.nav-mobile[hidden]{ display:none; }
.nav-mobile-inner{ display:grid; gap:8px; padding:12px var(--container-pad) 16px; }
.nav-mobile-link{ text-decoration:none; color:var(--text); border:1px solid var(--border); border-radius:12px; padding:12px; }
.nav-mobile-link:active{ transform:translateY(1px); }
.mobile-cta{ width:100%; text-align:center; }

/* Hero image should not overflow on small devices */
.hero-visual img{ width:100%; height:auto; max-width:100%; }

/* Cards grid already collapses at 980px; tighten further for narrow phones */
@media (max-width: 640px){
  .hero-text h1{ font-size: clamp(24px, 7vw, 32px); }
  .lead{ font-size: 0.95rem; }
  .head-inner{ gap:10px; }
  .nav-cta{ display:none; }          /* hide desktop CTA */
  .nav--desktop{ display:none; }     /* hide desktop nav */
  .hamburger{ display:inline-flex; align-items:center; justify-content:center; }
  .hero{ gap:16px; }
  .card{ padding:14px; }
  .container{ padding: 16px; }
  .foot-grid{ grid-template-columns: 1fr; }
  .btn{ padding:10px 12px; }
}

/* Medium breakpoint polish */
@media (min-width: 641px) and (max-width: 980px){
  .nav--desktop{ display:none; }
  .nav-cta{ display:none; }
  .hamburger{ display:inline-flex; align-items:center; justify-content:center; }
}