/* ==========================================================================
   VN TOOLS — Design System
   Signature: the hero IS the tool search — a live command bar, not a banner.
   ========================================================================== */

/* ---- Fonts (self-hosted-ready; using preconnect + swap in HTML) ---- */

:root{
  /* Color tokens — Light */
  --bg: #F7F8FB;
  --surface: #FFFFFF;
  --surface-2: #EEF0F7;
  --border: #E2E5F0;
  --text: #171A2B;
  --text-muted: #5C6178;
  --primary: #4F46E5;
  --primary-dark: #372FBE;
  --primary-tint: #EDEBFC;
  --accent: #F59E0B;
  --accent-tint: #FFF3DE;
  --success: #16A34A;
  --danger: #DC2626;

  /* Glass */
  --glass-bg: rgba(255,255,255,0.65);
  --glass-border: rgba(255,255,255,0.4);

  /* Type */
  --font-display: 'Space Grotesk', 'Segoe UI', sans-serif;
  --font-body: 'Inter', 'Segoe UI', sans-serif;
  --font-mono: 'JetBrains Mono', 'Consolas', monospace;

  /* Radius / shadow / motion */
  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 22px;
  --shadow-sm: 0 1px 2px rgba(23,26,43,0.06);
  --shadow-md: 0 8px 24px rgba(23,26,43,0.08);
  --shadow-lg: 0 20px 50px rgba(23,26,43,0.14);
  --ease: cubic-bezier(.4,0,.2,1);

  --header-h: 68px;
  --container: 1180px;
}

[data-theme="dark"]{
  --bg: #0B0E17;
  --surface: #131726;
  --surface-2: #1B2032;
  --border: #262C42;
  --text: #E7E9F5;
  --text-muted: #9AA0BC;
  --primary: #6C63FF;
  --primary-dark: #8D86FF;
  --primary-tint: #1E1B3A;
  --accent: #FBBF24;
  --accent-tint: #2B2210;
  --glass-bg: rgba(19,23,38,0.6);
  --glass-border: rgba(255,255,255,0.08);
  --shadow-sm: 0 1px 2px rgba(0,0,0,0.3);
  --shadow-md: 0 8px 24px rgba(0,0,0,0.35);
  --shadow-lg: 0 20px 50px rgba(0,0,0,0.5);
}

*,*::before,*::after{ box-sizing:border-box; }
html{ scroll-behavior:smooth; }
@media (prefers-reduced-motion:reduce){
  html{ scroll-behavior:auto; }
  *,*::before,*::after{ animation-duration:0.001ms !important; animation-iteration-count:1 !important; transition-duration:0.001ms !important; }
}

body{
  margin:0;
  background:var(--bg);
  color:var(--text);
  font-family:var(--font-body);
  line-height:1.55;
  -webkit-font-smoothing:antialiased;
  transition:background .25s var(--ease), color .25s var(--ease);
}

img{ max-width:100%; display:block; }
a{ color:inherit; text-decoration:none; }
button{ font-family:inherit; }
:focus-visible{ outline:2px solid var(--primary); outline-offset:2px; border-radius:4px; }

.container{ max-width:var(--container); margin:0 auto; padding:0 20px; }
.sr-only{ position:absolute; width:1px; height:1px; overflow:hidden; clip:rect(0 0 0 0); white-space:nowrap; }

h1,h2,h3,h4{ font-family:var(--font-display); font-weight:600; line-height:1.15; margin:0 0 .5em; letter-spacing:-0.01em; }
p{ margin:0 0 1em; color:var(--text-muted); }
code, .mono{ font-family:var(--font-mono); }

/* ---- Header ---- */
.site-header{
  position:sticky; top:0; z-index:50;
  height:var(--header-h);
  display:flex; align-items:center;
  background:var(--glass-bg);
  backdrop-filter:blur(14px) saturate(160%);
  -webkit-backdrop-filter:blur(14px) saturate(160%);
  border-bottom:1px solid var(--border);
}
.site-header .container{ display:flex; align-items:center; gap:24px; justify-content:space-between; }
.brand{ display:flex; align-items:center; gap:10px; font-family:var(--font-display); font-weight:700; font-size:1.2rem; color:var(--text); }
.brand-mark{ width:32px; height:32px; border-radius:9px; background:linear-gradient(135deg,var(--primary),var(--accent)); display:flex; align-items:center; justify-content:center; color:#fff; font-weight:700; font-size:.95rem; flex-shrink:0; }
.main-nav{ display:flex; gap:22px; align-items:center; }
.main-nav a{ font-size:.92rem; color:var(--text-muted); font-weight:500; transition:color .15s var(--ease); }
.main-nav a:hover{ color:var(--primary); }
.header-actions{ display:flex; align-items:center; gap:10px; }

.theme-toggle{
  width:40px; height:40px; border-radius:50%; border:1px solid var(--border);
  background:var(--surface); color:var(--text); cursor:pointer;
  display:flex; align-items:center; justify-content:center;
  transition:transform .2s var(--ease), background .2s var(--ease);
}
.theme-toggle:hover{ transform:rotate(15deg); }
.theme-toggle svg{ width:18px; height:18px; }
[data-theme="dark"] .icon-sun{ display:block; }
[data-theme="dark"] .icon-moon{ display:none; }
.icon-sun{ display:none; }
.icon-moon{ display:block; }

.nav-toggle{ display:none; width:40px; height:40px; border-radius:9px; border:1px solid var(--border); background:var(--surface); cursor:pointer; align-items:center; justify-content:center; }

/* ---- Buttons ---- */
.btn{
  display:inline-flex; align-items:center; justify-content:center; gap:8px;
  padding:11px 20px; border-radius:var(--radius-sm); font-weight:600; font-size:.92rem;
  border:1px solid transparent; cursor:pointer; transition:all .18s var(--ease);
  white-space:nowrap;
}
.btn-primary{ background:var(--primary); color:#fff; box-shadow:var(--shadow-sm); }
.btn-primary:hover{ background:var(--primary-dark); transform:translateY(-1px); box-shadow:var(--shadow-md); }
.btn-ghost{ background:transparent; border-color:var(--border); color:var(--text); }
.btn-ghost:hover{ background:var(--surface-2); }
.btn-accent{ background:var(--accent); color:#231a00; }
.btn-sm{ padding:7px 14px; font-size:.82rem; }
.btn-block{ width:100%; }

/* ---- Hero / Command Search (signature element) ---- */
.hero{
  padding:64px 0 40px;
  background:
    radial-gradient(60% 60% at 15% 0%, var(--primary-tint), transparent 60%),
    radial-gradient(50% 50% at 100% 10%, var(--accent-tint), transparent 60%);
}
.hero-eyebrow{ display:inline-block; font-size:.78rem; font-weight:700; letter-spacing:.06em; text-transform:uppercase; color:var(--primary); background:var(--primary-tint); padding:6px 12px; border-radius:100px; margin-bottom:18px; }
.hero h1{ font-size:clamp(2rem,5vw,3.2rem); max-width:760px; }
.hero h1 .accent{ color:var(--primary); }
.hero-sub{ font-size:1.08rem; max-width:600px; margin-bottom:32px; }

.command-bar{
  max-width:720px;
  background:var(--surface);
  border:1px solid var(--border);
  border-radius:var(--radius-lg);
  box-shadow:var(--shadow-lg);
  padding:8px;
  position:relative;
}
.command-bar-inner{ display:flex; align-items:center; gap:10px; padding:10px 14px; }
.command-bar-inner svg{ flex-shrink:0; color:var(--text-muted); width:20px; height:20px; }
#toolSearch{
  flex:1; border:none; outline:none; background:transparent; color:var(--text);
  font-size:1rem; font-family:var(--font-body); padding:6px 0;
}
#toolSearch::placeholder{ color:var(--text-muted); }
.command-kbd{ font-size:.75rem; color:var(--text-muted); border:1px solid var(--border); border-radius:6px; padding:2px 7px; font-family:var(--font-mono); }

.search-results{
  position:absolute; left:0; right:0; top:calc(100% + 8px);
  background:var(--surface); border:1px solid var(--border); border-radius:var(--radius-md);
  box-shadow:var(--shadow-lg); max-height:360px; overflow-y:auto; z-index:40;
  display:none;
}
.search-results.open{ display:block; }
.search-results a{ display:flex; align-items:center; gap:10px; padding:12px 16px; font-size:.92rem; border-bottom:1px solid var(--border); transition:background .12s; }
.search-results a:last-child{ border-bottom:none; }
.search-results a:hover, .search-results a.active{ background:var(--surface-2); }
.search-results .tag{ margin-left:auto; font-size:.72rem; color:var(--text-muted); background:var(--surface-2); padding:2px 8px; border-radius:100px; }
.search-empty{ padding:16px; color:var(--text-muted); font-size:.9rem; }

.hero-chips{ display:flex; flex-wrap:wrap; gap:8px; margin-top:18px; }
.chip{ font-size:.82rem; padding:6px 13px; border-radius:100px; background:var(--surface); border:1px solid var(--border); color:var(--text-muted); transition:.15s var(--ease); }
.chip:hover{ border-color:var(--primary); color:var(--primary); }

.hero-stats{ display:flex; gap:36px; margin-top:44px; flex-wrap:wrap; }
.stat-num{ font-family:var(--font-display); font-size:1.7rem; font-weight:700; color:var(--text); }
.stat-label{ font-size:.82rem; color:var(--text-muted); }

/* ---- Sections ---- */
.section{ padding:56px 0; }
.section-head{ display:flex; align-items:flex-end; justify-content:space-between; margin-bottom:28px; gap:20px; flex-wrap:wrap; }
.section-head h2{ font-size:1.6rem; margin:0; }
.section-head p{ margin:6px 0 0; }
.section-link{ font-size:.88rem; font-weight:600; color:var(--primary); }

/* ---- Category / tool grids ---- */
.grid{ display:grid; gap:16px; grid-template-columns:repeat(auto-fill,minmax(220px,1fr)); }
.grid-cat{ grid-template-columns:repeat(auto-fill,minmax(190px,1fr)); }

.card{
  background:var(--surface); border:1px solid var(--border); border-radius:var(--radius-md);
  padding:20px; transition:transform .18s var(--ease), box-shadow .18s var(--ease), border-color .18s var(--ease);
}
.card:hover{ transform:translateY(-3px); box-shadow:var(--shadow-md); border-color:var(--primary); }

.tool-card{ display:flex; flex-direction:column; gap:10px; }
.tool-icon{
  width:42px; height:42px; border-radius:11px; background:var(--primary-tint); color:var(--primary);
  display:flex; align-items:center; justify-content:center; flex-shrink:0;
}
.tool-icon svg{ width:22px; height:22px; }
.tool-card h3{ font-size:1rem; margin:0; }
.tool-card p{ font-size:.85rem; margin:0; }
.tool-card .badge{ font-size:.7rem; font-weight:700; color:var(--accent); text-transform:uppercase; letter-spacing:.04em; }

.cat-card{ text-align:center; padding:22px 14px; }
.cat-card .tool-icon{ margin:0 auto 12px; }
.cat-card h3{ font-size:.92rem; }
.cat-card span{ font-size:.78rem; color:var(--text-muted); }

/* ---- Tool page layout ---- */
.tool-page-hero{ padding:36px 0 8px; }
.breadcrumb{ font-size:.82rem; color:var(--text-muted); margin-bottom:14px; display:flex; gap:6px; flex-wrap:wrap; }
.breadcrumb a{ color:var(--text-muted); }
.breadcrumb a:hover{ color:var(--primary); }

.tool-layout{ display:grid; grid-template-columns:1fr 300px; gap:28px; align-items:start; }
.tool-panel{
  background:var(--surface); border:1px solid var(--border); border-radius:var(--radius-lg);
  padding:28px; box-shadow:var(--shadow-sm);
}
.tool-panel label{ display:block; font-size:.85rem; font-weight:600; margin-bottom:8px; }
.field{ margin-bottom:18px; }
.field-row{ display:grid; grid-template-columns:1fr 1fr; gap:14px; }

textarea, input[type="text"], input[type="number"], input[type="date"], select{
  width:100%; padding:12px 14px; border-radius:var(--radius-sm); border:1px solid var(--border);
  background:var(--bg); color:var(--text); font-family:var(--font-body); font-size:.95rem;
  transition:border-color .15s var(--ease);
}
textarea{ min-height:160px; resize:vertical; font-family:var(--font-mono); font-size:.88rem; }
input:focus, textarea:focus, select:focus{ border-color:var(--primary); }

.range-row{ display:flex; align-items:center; gap:12px; }
input[type="range"]{ flex:1; accent-color:var(--primary); }

.tool-actions{ display:flex; gap:10px; flex-wrap:wrap; margin-top:18px; }

.result-box{
  margin-top:20px; padding:18px; border-radius:var(--radius-md); background:var(--surface-2);
  border:1px solid var(--border); font-family:var(--font-mono); font-size:.9rem; white-space:pre-wrap; word-break:break-word;
  display:none;
}
.result-box.show{ display:block; }
.result-stat-grid{ display:grid; grid-template-columns:repeat(auto-fit,minmax(100px,1fr)); gap:12px; margin-top:16px; }
.result-stat{ background:var(--surface-2); border-radius:var(--radius-sm); padding:14px; text-align:center; }
.result-stat b{ display:block; font-family:var(--font-display); font-size:1.3rem; }
.result-stat span{ font-size:.75rem; color:var(--text-muted); }

.copy-toast{
  position:fixed; bottom:24px; left:50%; transform:translateX(-50%) translateY(20px);
  background:var(--text); color:var(--bg); padding:10px 18px; border-radius:100px; font-size:.85rem;
  opacity:0; pointer-events:none; transition:.25s var(--ease); z-index:100;
}
.copy-toast.show{ opacity:1; transform:translateX(-50%) translateY(0); }

/* sidebar */
.side-block{ background:var(--surface); border:1px solid var(--border); border-radius:var(--radius-md); padding:20px; margin-bottom:16px; }
.side-block h4{ font-size:.9rem; margin-bottom:12px; }
.related-list a{ display:block; font-size:.86rem; padding:8px 0; border-bottom:1px solid var(--border); color:var(--text-muted); }
.related-list a:last-child{ border:none; }
.related-list a:hover{ color:var(--primary); }
.ad-slot{ background:var(--surface-2); border:1px dashed var(--border); border-radius:var(--radius-sm); display:flex; align-items:center; justify-content:center; color:var(--text-muted); font-size:.78rem; min-height:250px; }
.ad-slot.leaderboard{ min-height:90px; margin:32px 0; }
.ad-slot.sticky-mobile{ position:fixed; bottom:0; left:0; right:0; z-index:60; min-height:56px; display:none; }

/* FAQ */
.faq-item{ border-bottom:1px solid var(--border); }
.faq-q{ width:100%; text-align:left; background:none; border:none; padding:18px 0; display:flex; justify-content:space-between; align-items:center; font-weight:600; font-size:.98rem; color:var(--text); cursor:pointer; }
.faq-q svg{ transition:transform .2s var(--ease); flex-shrink:0; color:var(--text-muted); }
.faq-item.open .faq-q svg{ transform:rotate(45deg); }
.faq-a{ max-height:0; overflow:hidden; transition:max-height .25s var(--ease); }
.faq-item.open .faq-a{ max-height:400px; }
.faq-a p{ padding-bottom:18px; margin:0; }

/* content / article */
.prose{ max-width:760px; margin:0 auto; }
.prose h2{ font-size:1.4rem; margin-top:2em; }
.prose h3{ font-size:1.15rem; margin-top:1.6em; }
.prose ul, .prose ol{ color:var(--text-muted); padding-left:1.3em; }
.prose li{ margin-bottom:.4em; }
.prose table{ width:100%; border-collapse:collapse; margin:1.5em 0; font-size:.9rem; }
.prose th, .prose td{ border:1px solid var(--border); padding:10px 12px; text-align:left; }
.prose th{ background:var(--surface-2); }
.article-meta{ display:flex; gap:14px; align-items:center; color:var(--text-muted); font-size:.85rem; margin-bottom:8px; }

/* newsletter */
.newsletter{ background:linear-gradient(135deg,var(--primary),var(--primary-dark)); border-radius:var(--radius-lg); padding:44px; color:#fff; text-align:center; }
.newsletter h2{ color:#fff; }
.newsletter p{ color:rgba(255,255,255,.85); }
.newsletter-form{ display:flex; gap:10px; max-width:420px; margin:20px auto 0; }
.newsletter-form input{ background:rgba(255,255,255,.15); border:1px solid rgba(255,255,255,.3); color:#fff; }
.newsletter-form input::placeholder{ color:rgba(255,255,255,.7); }

/* footer */
.site-footer{ background:var(--surface); border-top:1px solid var(--border); margin-top:60px; padding:48px 0 24px; }
.footer-grid{ display:grid; grid-template-columns:2fr repeat(4,1fr); gap:28px; }
.footer-grid h4{ font-size:.85rem; margin-bottom:14px; text-transform:uppercase; letter-spacing:.04em; }
.footer-grid a{ display:block; font-size:.87rem; color:var(--text-muted); padding:5px 0; }
.footer-grid a:hover{ color:var(--primary); }
.footer-bottom{ margin-top:36px; padding-top:20px; border-top:1px solid var(--border); display:flex; justify-content:space-between; align-items:center; flex-wrap:wrap; gap:12px; font-size:.82rem; color:var(--text-muted); }
.footer-social{ display:flex; gap:10px; }
.footer-social a{ width:34px; height:34px; border-radius:50%; border:1px solid var(--border); display:flex; align-items:center; justify-content:center; }

.back-to-top{
  position:fixed; right:20px; bottom:20px; width:44px; height:44px; border-radius:50%;
  background:var(--primary); color:#fff; display:flex; align-items:center; justify-content:center;
  box-shadow:var(--shadow-md); opacity:0; pointer-events:none; transform:translateY(10px);
  transition:.2s var(--ease); z-index:55; border:none; cursor:pointer;
}
.back-to-top.show{ opacity:1; pointer-events:auto; transform:translateY(0); }

/* utility */
.text-center{ text-align:center; }
.mt-0{ margin-top:0; }
.badge-new{ background:var(--accent); color:#231a00; font-size:.7rem; font-weight:700; padding:2px 8px; border-radius:100px; }

@media (max-width:900px){
  .tool-layout{ grid-template-columns:1fr; }
  .footer-grid{ grid-template-columns:repeat(2,1fr); }
}
@media (max-width:720px){
  .main-nav{ display:none; }
  .nav-toggle{ display:flex; }
  .hero{ padding:40px 0 30px; }
  .field-row{ grid-template-columns:1fr; }
  .ad-slot.sticky-mobile{ display:flex; }
}