/* ============================================================
   VIRTUNODE — Global Stylesheet
   ============================================================ */

@import url('https://fonts.googleapis.com/css2?family=Poppins:wght@300;400;500;600;700;800&family=JetBrains+Mono:wght@400;500&display=swap');

/* ---- CSS Variables ---- */
:root {
  --bg:          #090909;
  --bg-card:     #111111;
  --bg-card-2:   #161616;
  --border:      #1f1f1f;
  --border-2:    #2a2a2a;
  --text:        #f0f0f0;
  --text-muted:  #888888;
  --text-dim:    #555555;
  --accent:      #4F8EF7;
  --accent-dim:  rgba(79, 142, 247, 0.12);
  --accent-glow: rgba(79, 142, 247, 0.25);
  --radius:      12px;
  --radius-sm:   8px;
  --transition:  0.25s cubic-bezier(0.4, 0, 0.2, 1);
}

[data-theme="light"] {
  --bg:          #f5f5f5;
  --bg-card:     #ffffff;
  --bg-card-2:   #efefef;
  --border:      #e0e0e0;
  --border-2:    #d0d0d0;
  --text:        #0d0d0d;
  --text-muted:  #666666;
  --text-dim:    #aaaaaa;
  --accent-dim:  rgba(79, 142, 247, 0.08);
  --accent-glow: rgba(79, 142, 247, 0.18);
}

/* ---- Reset ---- */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html { scroll-behavior: smooth; font-size: 16px; }

body {
  font-family: 'Poppins', sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  min-height: 100vh;
  transition: background var(--transition), color var(--transition);
  overflow-x: hidden;
}

img { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; }
ul { list-style: none; }
button { cursor: pointer; font-family: inherit; border: none; background: none; }
input, textarea, select { font-family: inherit; }

/* ---- Utility ---- */
.container { max-width: 1100px; margin: 0 auto; padding: 0 24px; }
.container-wide { max-width: 1280px; margin: 0 auto; padding: 0 24px; }
.mono { font-family: 'JetBrains Mono', monospace; }

/* ---- Logo images (theme-aware) ---- */
.logo-dark { display: block; }
.logo-light { display: none; }
[data-theme="light"] .logo-dark { display: none; }
[data-theme="light"] .logo-light { display: block; }
.nav-logo-icon {
  width: 32px; height: 32px;
  border-radius: 6px;
  flex-shrink: 0;
}
.footer-logo-icon {
  width: 22px; height: 22px;
  border-radius: 4px;
  flex-shrink: 0;
}

/* ---- Navbar ---- */
.navbar {
  position: fixed; top: 0; left: 0; right: 0; z-index: 999;
  padding: 0 32px;
  height: 64px;
  display: flex; align-items: center; justify-content: space-between;
  border-bottom: 1px solid transparent;
  transition: background var(--transition), border-color var(--transition), backdrop-filter var(--transition);
}
.navbar.scrolled {
  background: rgba(9,9,9,0.85);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-color: var(--border);
}
[data-theme="light"] .navbar.scrolled {
  background: rgba(245,245,245,0.85);
}
.nav-logo {
  font-size: 1.2rem; font-weight: 700; letter-spacing: -0.5px;
  display: flex; align-items: center; gap: 8px;
}
.vn-accent { color: var(--accent); }
.nav-links { display: flex; align-items: center; gap: 32px; }
.nav-links a {
  font-size: 0.875rem; font-weight: 500; color: var(--text-muted);
  transition: color var(--transition);
}
.nav-links a:hover, .nav-links a.active { color: var(--text); }
.nav-right { display: flex; align-items: center; gap: 16px; }

/* Theme Toggle */
.theme-toggle {
  width: 40px; height: 40px;
  border-radius: 50%;
  display: flex; align-items: center; justify-content: center;
  background: var(--bg-card);
  border: 1px solid var(--border);
  color: var(--text-muted);
  transition: all var(--transition);
}
.theme-toggle:hover { color: var(--text); border-color: var(--border-2); }
.theme-toggle svg { width: 16px; height: 16px; }
.icon-sun { display: none; }
.icon-moon { display: block; }
[data-theme="light"] .icon-sun { display: block; }
[data-theme="light"] .icon-moon { display: none; }

/* Mobile menu */
.nav-hamburger {
  display: none; width: 40px; height: 40px;
  align-items: center; justify-content: center;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border);
  color: var(--text-muted);
}
.nav-hamburger svg { width: 20px; height: 20px; }

@media (max-width: 768px) {
  .nav-links { display: none; }
  .nav-hamburger { display: flex; }
  .nav-links.open {
    display: flex; flex-direction: column; position: fixed;
    top: 64px; left: 0; right: 0;
    background: var(--bg-card);
    border-bottom: 1px solid var(--border);
    padding: 24px; gap: 20px; align-items: flex-start;
  }
}

/* ---- Buttons ---- */
.btn {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 12px 24px; border-radius: var(--radius-sm);
  font-size: 0.875rem; font-weight: 600;
  transition: all var(--transition); white-space: nowrap;
}
.btn-primary {
  background: var(--accent); color: #fff;
  box-shadow: 0 0 24px var(--accent-glow);
}
.btn-primary:hover {
  background: #6ba3f8;
  box-shadow: 0 0 36px var(--accent-glow);
  transform: translateY(-1px);
}
.btn-outline {
  border: 1px solid var(--border-2); color: var(--text-muted);
  background: transparent;
}
.btn-outline:hover {
  border-color: var(--accent); color: var(--accent);
  background: var(--accent-dim);
}
.btn-ghost {
  color: var(--accent); font-size: 0.875rem; font-weight: 500;
  display: inline-flex; align-items: center; gap: 6px;
}
.btn-ghost:hover { gap: 10px; }
.btn-ghost::after { content: '→'; transition: transform var(--transition); }

/* ---- Section Utilities ---- */
.section { padding: 96px 0; }
.section-sm { padding: 64px 0; }

.section-label {
  font-size: 0.7rem; font-weight: 600; letter-spacing: 0.15em;
  text-transform: uppercase; color: var(--accent);
  display: flex; align-items: center; gap: 8px; margin-bottom: 16px;
}
.section-label::before {
  content: ''; display: block; width: 20px; height: 1px; background: var(--accent);
}

.section-heading {
  font-size: clamp(1.75rem, 4vw, 2.5rem);
  font-weight: 700; line-height: 1.2; letter-spacing: -0.03em;
  margin-bottom: 16px;
}
.section-subtext {
  font-size: 1rem; color: var(--text-muted); max-width: 540px;
  line-height: 1.7;
}

/* ---- Cards ---- */
.card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px;
  transition: border-color var(--transition), transform var(--transition), box-shadow var(--transition);
}
.card:hover {
  border-color: var(--border-2);
  transform: translateY(-3px);
  box-shadow: 0 8px 40px rgba(0,0,0,0.3);
}
[data-theme="light"] .card:hover {
  box-shadow: 0 8px 40px rgba(0,0,0,0.08);
}

/* ---- Page Header (inner pages) ---- */
.page-header {
  padding: 140px 0 72px;
  border-bottom: 1px solid var(--border);
  background: var(--bg);
  position: relative; overflow: hidden;
}
.page-header::before {
  content: '';
  position: absolute; top: 0; left: 0; right: 0; bottom: 0;
  background: radial-gradient(ellipse 60% 50% at 20% 60%, var(--accent-dim) 0%, transparent 70%);
  pointer-events: none;
}
.page-header-label {
  font-size: 0.7rem; font-weight: 600; letter-spacing: 0.15em;
  text-transform: uppercase; color: var(--accent); margin-bottom: 16px;
}
.page-header h1 {
  font-size: clamp(2rem, 5vw, 3.25rem);
  font-weight: 800; letter-spacing: -0.04em; line-height: 1.1;
  margin-bottom: 16px;
}
.page-header p {
  font-size: 1.05rem; color: var(--text-muted); max-width: 560px; line-height: 1.7;
}

/* ---- Footer ---- */
footer {
  border-top: 1px solid var(--border);
  padding: 48px 0;
}
.footer-inner {
  display: flex; align-items: center; justify-content: space-between; gap: 24px;
  flex-wrap: wrap;
}
.footer-logo { font-size: 1rem; font-weight: 700; letter-spacing: -0.5px; display: flex; align-items: center; gap: 8px; }
.footer-logo .vn-accent { color: var(--accent); }
.footer-links { display: flex; gap: 24px; flex-wrap: wrap; }
.footer-links a {
  font-size: 0.8rem; color: var(--text-dim);
  transition: color var(--transition);
}
.footer-links a:hover { color: var(--text-muted); }
.footer-copy { font-size: 0.75rem; color: var(--text-dim); }

/* ---- Fade-in Animations ---- */
.fade-in {
  opacity: 0; transform: translateY(24px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}
.fade-in.visible { opacity: 1; transform: none; }

/* ---- Divider ---- */
.divider { height: 1px; background: var(--border); margin: 0; }

/* ---- Tag ---- */
.tag {
  display: inline-flex; align-items: center;
  padding: 4px 12px; border-radius: 99px;
  font-size: 0.75rem; font-weight: 500;
  background: var(--accent-dim); color: var(--accent);
  border: 1px solid rgba(79,142,247,0.2);
}

/* ---- Doc pages (terms, privacy) ---- */
.doc-body { max-width: 760px; }
.doc-body h2 {
  font-size: 1.2rem; font-weight: 700;
  margin: 48px 0 12px; color: var(--text);
  padding-bottom: 8px; border-bottom: 1px solid var(--border);
}
.doc-body h2:first-child { margin-top: 0; }
.doc-body p { color: var(--text-muted); margin-bottom: 12px; line-height: 1.75; }
.doc-body ul { margin: 12px 0 16px 0; }
.doc-body ul li {
  color: var(--text-muted); padding: 4px 0 4px 20px; position: relative; line-height: 1.7;
}
.doc-body ul li::before {
  content: '—'; position: absolute; left: 0; color: var(--accent);
}
.doc-body .doc-meta {
  font-size: 0.8rem; color: var(--text-dim);
  margin-bottom: 48px; padding-bottom: 24px; border-bottom: 1px solid var(--border);
}

/* ---- Contact form ---- */
.form-group { margin-bottom: 20px; }
.form-group label {
  display: block; font-size: 0.8rem; font-weight: 500;
  color: var(--text-muted); margin-bottom: 8px; letter-spacing: 0.02em;
}
.form-group input,
.form-group textarea,
.form-group select {
  width: 100%; padding: 12px 16px;
  background: var(--bg-card-2); border: 1px solid var(--border);
  border-radius: var(--radius-sm); color: var(--text);
  font-size: 0.9rem; transition: border-color var(--transition), box-shadow var(--transition);
}
.form-group input:focus,
.form-group textarea:focus,
.form-group select:focus {
  outline: none; border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-dim);
}
.form-group textarea { resize: vertical; min-height: 120px; }
.form-group select option { background: var(--bg-card); }
.form-note { font-size: 0.75rem; color: var(--text-dim); margin-top: 16px; }

/* ---- Service detail blocks ---- */
.service-block { padding: 56px 0; border-bottom: 1px solid var(--border); }
.service-block:last-child { border-bottom: none; }
.service-block-inner {
  display: grid; grid-template-columns: 1fr 1fr; gap: 64px; align-items: start;
}
@media (max-width: 768px) {
  .service-block-inner { grid-template-columns: 1fr; gap: 32px; }
}
.service-number {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.75rem; color: var(--accent); margin-bottom: 12px;
}
.service-block h2 { font-size: 1.5rem; font-weight: 700; margin-bottom: 16px; letter-spacing: -0.02em; }
.service-block p { color: var(--text-muted); line-height: 1.75; margin-bottom: 24px; }
.service-outcomes {
  background: var(--bg-card-2); border: 1px solid var(--border);
  border-radius: var(--radius); padding: 20px 24px;
  border-left: 2px solid var(--accent);
}
.service-outcomes p { font-size: 0.875rem; font-style: italic; color: var(--text-muted); margin: 0; }
.deliverables { display: flex; flex-direction: column; gap: 8px; }
.deliverables li {
  font-size: 0.875rem; color: var(--text-muted);
  padding: 10px 14px; background: var(--bg-card);
  border: 1px solid var(--border); border-radius: var(--radius-sm);
  display: flex; align-items: center; gap: 10px;
}
.deliverables li::before { content: '✓'; color: var(--accent); font-weight: 700; font-size: 0.75rem; }

/* ---- About page ---- */
.about-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 80px; align-items: center; }
@media (max-width: 768px) { .about-grid { grid-template-columns: 1fr; gap: 48px; } }
.about-visual {
  aspect-ratio: 4/3; border-radius: var(--radius);
  background: var(--bg-card); border: 1px solid var(--border);
  display: flex; align-items: center; justify-content: center;
  position: relative; overflow: hidden;
}
.about-visual canvas { position: absolute; inset: 0; }
.pillars-grid { display: grid; grid-template-columns: repeat(3,1fr); gap: 20px; }
@media (max-width: 768px) { .pillars-grid { grid-template-columns: 1fr; } }

.callout-block {
  background: var(--bg-card); border: 1px solid var(--border);
  border-left: 3px solid var(--accent);
  border-radius: var(--radius); padding: 28px 32px;
  margin: 48px 0;
}
.callout-block p { color: var(--text-muted); line-height: 1.75; margin: 0; }

/* ---- Scrollbar ---- */
::-webkit-scrollbar { width: 6px; }
::-webkit-scrollbar-track { background: var(--bg); }
::-webkit-scrollbar-thumb { background: var(--border-2); border-radius: 99px; }