/* ===========================================================
   ZeroOS — Official Site
   Clean, professional corporate theme (light)
   =========================================================== */

:root {
  --bg:        #ffffff;
  --bg-soft:   #f7f8fa;
  --bg-muted:  #f1f3f7;
  --surface:   #ffffff;
  --border:    #e4e7ec;
  --border-2:  #d0d5dd;
  --ink:       #101828;
  --ink-2:     #344054;
  --muted:     #667085;
  --accent:    #1d4ed8;
  --accent-2:  #1e40af;
  --accent-soft: #eef2ff;
  --ring:      rgba(29, 78, 216, .16);
  --radius:    12px;
  --radius-sm: 8px;
  --radius-lg: 16px;
  --shadow-sm: 0 1px 2px rgba(16, 24, 40, .06), 0 1px 3px rgba(16, 24, 40, .08);
  --shadow:    0 4px 12px rgba(16, 24, 40, .06), 0 12px 28px -12px rgba(16, 24, 40, .12);
  --maxw:      1160px;
  --ease:      cubic-bezier(.22, .61, .36, 1);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  font-family: "Inter", "Segoe UI", system-ui, -apple-system, sans-serif;
  background: var(--bg);
  color: var(--ink-2);
  line-height: 1.65;
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

a { color: inherit; text-decoration: none; }
img, svg { display: block; max-width: 100%; }

h1, h2, h3, h4 { color: var(--ink); margin: 0 0 .5em; font-weight: 700; line-height: 1.2; letter-spacing: -.018em; }
h1 { font-size: clamp(2rem, 4.2vw, 3.1rem); font-weight: 800; }
h2 { font-size: clamp(1.55rem, 3vw, 2.2rem); }
h3 { font-size: 1.18rem; }
p  { margin: 0 0 1rem; color: var(--muted); }

.container { width: 100%; max-width: var(--maxw); margin: 0 auto; padding: 0 24px; }
.accent { color: var(--accent); }

/* ===================== Buttons ===================== */
.btn {
  display: inline-flex;
  align-items: center;
  gap: .5rem;
  padding: .72rem 1.35rem;
  border-radius: var(--radius-sm);
  font-weight: 600;
  font-size: .94rem;
  border: 1px solid transparent;
  cursor: pointer;
  transition: background .18s var(--ease), border-color .18s, color .18s, box-shadow .18s, transform .12s;
  white-space: nowrap;
}
.btn:active { transform: translateY(1px); }
.btn-primary { background: var(--accent); color: #fff; }
.btn-primary:hover { background: var(--accent-2); box-shadow: 0 6px 16px -6px var(--ring); }
.btn-ghost { background: var(--surface); border-color: var(--border-2); color: var(--ink); }
.btn-ghost:hover { background: var(--bg-soft); border-color: var(--accent); color: var(--accent); }
.btn-light { background: rgba(255,255,255,.14); color: #fff; border-color: rgba(255,255,255,.3); }
.btn-light:hover { background: rgba(255,255,255,.24); }
.btn .ico { width: 18px; height: 18px; }

/* link with arrow */
.link-arrow { display: inline-flex; align-items: center; gap: .4rem; color: var(--accent); font-weight: 600; font-size: .94rem; }
.link-arrow svg { width: 16px; height: 16px; transition: transform .18s var(--ease); }
.link-arrow:hover svg { transform: translateX(3px); }

/* ===================== Header / Nav ===================== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(255, 255, 255, .85);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid transparent;
  transition: border-color .25s, box-shadow .25s;
}
.site-header.scrolled { border-bottom-color: var(--border); box-shadow: var(--shadow-sm); }

.nav { display: flex; align-items: center; justify-content: space-between; height: 70px; }
.brand { display: flex; align-items: center; gap: .6rem; font-weight: 700; font-size: 1.1rem; letter-spacing: -.02em; color: var(--ink); }
.brand-logo { height: 40px; width: auto; display: block; }
@media (max-width: 600px) { .brand-logo { height: 34px; } }
.brand .logo {
  width: 32px; height: 32px;
  border-radius: 8px;
  background: var(--accent);
  display: grid; place-items: center;
  color: #fff; font-weight: 800; font-size: 1rem;
}
.nav-links { display: flex; align-items: center; gap: .15rem; list-style: none; margin: 0; padding: 0; }
.nav-links a {
  padding: .5rem .85rem;
  border-radius: var(--radius-sm);
  color: var(--ink-2);
  font-weight: 500;
  font-size: .94rem;
  transition: color .18s, background .18s;
}
.nav-links a:hover { color: var(--ink); background: var(--bg-soft); }
.nav-links a.active { color: var(--accent); }
.nav-cta { margin-left: .6rem; }

.nav-toggle {
  display: none;
  background: none; border: 1px solid var(--border-2);
  border-radius: var(--radius-sm);
  width: 42px; height: 42px;
  color: var(--ink); cursor: pointer;
}
.nav-toggle svg { width: 22px; height: 22px; margin: auto; }

/* ===================== Hero ===================== */
.hero { padding: clamp(3.5rem, 7vw, 6rem) 0 clamp(2.5rem, 5vw, 4.5rem); }
.hero-grid { display: grid; grid-template-columns: 1.05fr .95fr; gap: 3.5rem; align-items: center; }
.eyebrow {
  display: inline-flex; align-items: center; gap: .5rem;
  font-size: .78rem; font-weight: 600; letter-spacing: .04em; text-transform: uppercase;
  color: var(--accent);
  background: var(--accent-soft);
  border: 1px solid #e0e7ff;
  padding: .35rem .75rem; border-radius: 999px;
  margin-bottom: 1.25rem;
}
.hero h1 { color: var(--ink); }
.hero p.lead { font-size: 1.12rem; max-width: 46ch; color: var(--ink-2); }
.hero-actions { display: flex; gap: .85rem; flex-wrap: wrap; margin-top: 1.75rem; }
.hero-stats { display: flex; gap: 2.75rem; margin-top: 2.75rem; flex-wrap: wrap; }
.hero-stats .num { font-size: 1.85rem; font-weight: 800; color: var(--ink); letter-spacing: -.02em; }
.hero-stats .lbl { font-size: .85rem; color: var(--muted); }

/* hero visual — clean app mock */
.hero-art {
  position: relative;
  border-radius: var(--radius-lg);
  background: var(--bg-soft);
  border: 1px solid var(--border);
  box-shadow: var(--shadow);
  overflow: hidden;
}
.mock-bar { display: flex; align-items: center; gap: .4rem; padding: .8rem 1rem; border-bottom: 1px solid var(--border); background: #fff; }
.mock-bar i { width: 10px; height: 10px; border-radius: 50%; background: var(--border-2); }
.mock-bar i:nth-child(2){ background:#e4e7ec; } .mock-bar i:nth-child(3){ background:#eef0f4; }
.mock-bar span { margin-left: auto; font-size: .78rem; color: var(--muted); }
.mock-body { padding: 1.5rem; display: grid; gap: 1rem; }
.mock-row { display: grid; grid-template-columns: 40px 1fr auto; gap: .9rem; align-items: center; padding: .9rem; border: 1px solid var(--border); border-radius: var(--radius-sm); background: #fff; }
.mock-ico { width: 40px; height: 40px; border-radius: 9px; background: var(--accent-soft); display: grid; place-items: center; color: var(--accent); }
.mock-ico svg { width: 20px; height: 20px; }
.mock-line { height: 9px; border-radius: 5px; background: var(--bg-muted); }
.mock-line.short { width: 55%; margin-top: 6px; background: #eef0f4; }
.mock-pill { font-size: .72rem; font-weight: 600; color: var(--accent); background: var(--accent-soft); padding: .2rem .6rem; border-radius: 999px; }
.mock-pill.green { color: #027a48; background: #ecfdf3; }

/* ===================== Sections ===================== */
.section { padding: clamp(3rem, 6vw, 5rem) 0; }
.section.soft { background: var(--bg-soft); border-top: 1px solid var(--border); border-bottom: 1px solid var(--border); }
.section-head { max-width: 620px; margin: 0 auto 3rem; text-align: center; }
.section-head .eyebrow { margin-bottom: 1rem; }
.section-head p { font-size: 1.05rem; }

/* ===================== Grid / Cards ===================== */
.grid { display: grid; gap: 1.5rem; }
.grid-2 { grid-template-columns: repeat(2, 1fr); }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-4 { grid-template-columns: repeat(4, 1fr); }

.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.6rem;
  transition: border-color .2s, box-shadow .2s, transform .2s;
  position: relative;
}
.card:hover { border-color: var(--border-2); box-shadow: var(--shadow); transform: translateY(-3px); }
.card .icon {
  width: 46px; height: 46px;
  border-radius: 10px;
  display: grid; place-items: center;
  background: var(--accent-soft);
  color: var(--accent);
  margin-bottom: 1.1rem;
}
.card .icon svg { width: 23px; height: 23px; }
.card h3 { margin-bottom: .4rem; }
.card p { margin: 0; font-size: .95rem; }
.card .tag-row { display: flex; flex-wrap: wrap; gap: .4rem; margin-top: 1.1rem; }
.tag { font-size: .76rem; font-weight: 500; padding: .22rem .6rem; border-radius: 6px; background: var(--bg-muted); color: var(--ink-2); }

/* numbered step */
.step-num {
  width: 38px; height: 38px; border-radius: 9px;
  display: grid; place-items: center;
  background: var(--accent); color: #fff;
  font-weight: 700; font-size: 1rem; margin-bottom: 1.1rem;
}

/* product card */
.product-card { display: flex; flex-direction: column; }
.product-card .badge {
  position: absolute; top: 1.3rem; right: 1.3rem;
  font-size: .7rem; font-weight: 600; letter-spacing: .02em;
  padding: .22rem .6rem; border-radius: 999px;
  background: var(--accent-soft); color: var(--accent);
}
.product-card .badge.new { background: #ecfdf3; color: #027a48; }
.product-card .price { font-size: 1.4rem; font-weight: 800; color: var(--ink); margin-top: auto; padding-top: 1.2rem; }
.product-card .price span { font-size: .82rem; font-weight: 500; color: var(--muted); }
.feature-list { list-style: none; padding: 0; margin: 1rem 0 0; }
.feature-list li { display: flex; gap: .6rem; font-size: .92rem; color: var(--ink-2); margin-bottom: .55rem; align-items: flex-start; }
.feature-list li svg { width: 18px; height: 18px; color: var(--accent); flex: none; margin-top: 2px; }

/* ===================== Logos / trust ===================== */
.logo-row { display: flex; flex-wrap: wrap; gap: 2.5rem 3.5rem; justify-content: center; align-items: center; }
.logo-row span { font-weight: 700; font-size: 1.2rem; letter-spacing: -.02em; color: #98a2b3; }

/* ===================== Split ===================== */
.split { display: grid; grid-template-columns: 1fr 1fr; gap: 3.5rem; align-items: center; }

/* ===================== Timeline ===================== */
.timeline { position: relative; padding-left: 1.85rem; }
.timeline::before { content: ""; position: absolute; left: 5px; top: 8px; bottom: 8px; width: 2px; background: var(--border); }
.timeline-item { position: relative; margin-bottom: 1.85rem; }
.timeline-item:last-child { margin-bottom: 0; }
.timeline-item::before {
  content: ""; position: absolute; left: -1.85rem; top: 6px;
  width: 12px; height: 12px; border-radius: 50%;
  background: #fff; border: 3px solid var(--accent);
}
.timeline-item .year { font-weight: 700; color: var(--accent); font-size: .85rem; letter-spacing: .02em; }
.timeline-item strong { display: block; color: var(--ink); margin-top: .1rem; }
.timeline-item p { margin: .25rem 0 0; font-size: .92rem; }

/* ===================== CTA band ===================== */
.cta-band {
  background: var(--accent);
  border-radius: var(--radius-lg);
  padding: clamp(2.5rem, 5vw, 3.75rem);
  text-align: center;
  color: #fff;
}
.cta-band h2 { color: #fff; margin-bottom: .5rem; }
.cta-band p { color: rgba(255,255,255,.85); max-width: 52ch; margin-inline: auto; }
.cta-band .hero-actions { justify-content: center; margin-top: 1.75rem; }

/* stat band (about) */
.stat-band { display: grid; grid-template-columns: repeat(4, 1fr); gap: 2rem; text-align: center; }
.stat-band .num { font-size: clamp(2rem, 3.5vw, 2.6rem); font-weight: 800; color: var(--ink); letter-spacing: -.02em; }
.stat-band .lbl { color: var(--muted); font-size: .92rem; }

/* ===================== Footer ===================== */
.site-footer { border-top: 1px solid var(--border); margin-top: 0; padding: 3.5rem 0 2rem; background: var(--bg-soft); }
.footer-grid { display: grid; grid-template-columns: 1.7fr 1fr 1fr 1fr; gap: 2.5rem; }
.footer-grid h4 { font-size: .82rem; text-transform: uppercase; letter-spacing: .05em; color: var(--ink); margin: 0 0 1.1rem; }
.footer-grid ul { list-style: none; padding: 0; margin: 0; }
.footer-grid li { margin-bottom: .6rem; }
.footer-grid a { color: var(--muted); font-size: .93rem; transition: color .18s; }
.footer-grid a:hover { color: var(--accent); }
.footer-brand p { max-width: 36ch; font-size: .93rem; margin-top: 1rem; }
.footer-bottom {
  display: flex; justify-content: space-between; flex-wrap: wrap; gap: 1rem;
  margin-top: 2.75rem; padding-top: 1.5rem; border-top: 1px solid var(--border);
  color: var(--muted); font-size: .86rem;
}
.social { display: flex; gap: .55rem; }
.social a {
  width: 36px; height: 36px; border-radius: var(--radius-sm);
  display: grid; place-items: center;
  border: 1px solid var(--border); background: #fff; color: var(--muted);
  transition: border-color .18s, color .18s;
}
.social a:hover { border-color: var(--accent); color: var(--accent); }
.social svg { width: 18px; height: 18px; }

/* ===================== Inner page hero ===================== */
.page-hero { padding: clamp(3rem, 6vw, 4.5rem) 0 clamp(1rem, 2vw, 1.5rem); text-align: center; }
.page-hero p { max-width: 60ch; margin-inline: auto; font-size: 1.08rem; }

/* ===================== Contact ===================== */
.contact-grid { display: grid; grid-template-columns: 1.1fr .9fr; gap: 3rem; align-items: start; }
.form-group { margin-bottom: 1.15rem; }
.form-group label { display: block; font-size: .86rem; font-weight: 600; color: var(--ink); margin-bottom: .4rem; }
.form-group input, .form-group select, .form-group textarea {
  width: 100%;
  padding: .72rem .9rem;
  background: #fff;
  border: 1px solid var(--border-2);
  border-radius: var(--radius-sm);
  color: var(--ink);
  font-family: inherit;
  font-size: .95rem;
  transition: border-color .18s, box-shadow .18s;
}
.form-group input::placeholder, .form-group textarea::placeholder { color: #98a2b3; }
.form-group input:focus, .form-group select:focus, .form-group textarea:focus {
  outline: none; border-color: var(--accent); box-shadow: 0 0 0 3px var(--ring);
}
.form-group textarea { resize: vertical; min-height: 130px; }
.form-note { font-size: .82rem; color: var(--muted); margin-top: 1rem; }
.form-success {
  display: none;
  background: #ecfdf3; border: 1px solid #abefc6; color: #027a48;
  padding: .85rem 1.05rem; border-radius: var(--radius-sm);
  margin-bottom: 1.1rem; font-weight: 600; font-size: .92rem;
}
.contact-info .info-item { display: flex; gap: 1rem; margin-bottom: 1.6rem; }
.contact-info .info-item .icon {
  width: 44px; height: 44px; flex: none; border-radius: 10px;
  display: grid; place-items: center; color: var(--accent);
  background: var(--accent-soft);
}
.contact-info .info-item .icon svg { width: 21px; height: 21px; }
.contact-info .info-item strong { display: block; color: var(--ink); }
.contact-info .info-item span, .contact-info .info-item a { color: var(--muted); font-size: .94rem; }
.contact-info .info-item a:hover { color: var(--accent); }

/* ===================== Reveal ===================== */
.reveal { opacity: 0; transform: translateY(18px); transition: opacity .55s var(--ease), transform .55s var(--ease); }
.reveal.in { opacity: 1; transform: none; }
@media (prefers-reduced-motion: reduce) { .reveal { opacity: 1; transform: none; transition: none; } }

/* ===================== Responsive ===================== */
@media (max-width: 900px) {
  .hero-grid { grid-template-columns: 1fr; gap: 2.5rem; }
  .hero-art { max-width: 480px; }
  .grid-4 { grid-template-columns: repeat(2, 1fr); }
  .split, .contact-grid { grid-template-columns: 1fr; gap: 2.25rem; }
  .stat-band { grid-template-columns: repeat(2, 1fr); gap: 2rem 1rem; }
  .footer-grid { grid-template-columns: 1fr 1fr; gap: 2rem; }
}
@media (max-width: 640px) {
  .nav-links {
    position: fixed; inset: 70px 0 auto 0;
    flex-direction: column; align-items: stretch;
    background: #fff;
    border-bottom: 1px solid var(--border);
    box-shadow: var(--shadow);
    padding: .75rem; gap: .15rem;
    transform: translateY(-130%);
    transition: transform .3s var(--ease);
    z-index: 40;
  }
  .nav-links.open { transform: translateY(0); }
  .nav-links a { padding: .8rem 1rem; }
  .nav-toggle { display: grid; }
  .nav-cta { display: none; }
  .grid-2, .grid-3, .grid-4 { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr; }
  .hero-stats { gap: 1.75rem; }
}