/* =========================================================
   AMP Validator — SEOWebChecker.com
   Design tokens: "signal trace" system.
   Signature element: an animated lightning-trace scanline
   that sweeps a browser mockup while validation runs —
   echoing AMP's own bolt mark and its promise of speed.
   ========================================================= */

:root{
  --ink-950:#0B0F19;
  --ink-900:#111726;
  --ink-800:#171F32;
  --ink-700:#232C42;
  --ink-500:#5B6478;
  --ink-200:#C9CEDA;
  --paper-050:#F6F7FB;
  --paper-000:#FFFFFF;

  --volt:#2F6FED;      /* electric blue — primary */
  --volt-dim:#1F4FB0;
  --bolt:#FFC800;      /* AMP-esque lightning yellow — secondary */
  --good:#16C784;
  --warn:#FFA83E;
  --bad:#FF4757;

  --font-display:'Outfit', 'Inter', sans-serif;
  --font-body:'Inter', sans-serif;

  --radius-s:8px;
  --radius-m:14px;
  --radius-l:22px;

  --bg: var(--paper-050);
  --surface: var(--paper-000);
  --surface-2: #EEF1F8;
  --text: var(--ink-900);
  --text-dim: var(--ink-500);
  --border: #E1E5F0;
  --header-bg: rgba(255,255,255,0.86);
  --shadow: 0 10px 30px -12px rgba(17, 23, 38, 0.18);
}

[data-theme="dark"]{
  --bg: var(--ink-950);
  --surface: var(--ink-900);
  --surface-2: var(--ink-800);
  --text: #F2F4F9;
  --text-dim: #9BA3B7;
  --border: var(--ink-700);
  --header-bg: rgba(11,15,25,0.82);
  --shadow: 0 10px 34px -12px rgba(0,0,0,0.55);
}

*,*::before,*::after{box-sizing:border-box;}
html{scroll-behavior:smooth;}
body{
  margin:0;
  background:var(--bg);
  color:var(--text);
  font-family:var(--font-body);
  font-size:16px;
  line-height:1.6;
  -webkit-font-smoothing:antialiased;
  overflow-x:hidden;
  transition:background .25s ease,color .25s ease;
}
img{max-width:100%;display:block;}
a{color:inherit;text-decoration:none;}
h1,h2,h3,h4{font-family:var(--font-display);margin:0 0 .5em;line-height:1.15;letter-spacing:-0.01em;}
p{margin:0 0 1em;}
button{font-family:inherit;cursor:pointer;}
.container{max-width:1180px;margin:0 auto;padding:0 24px;}
.visually-hidden{position:absolute;width:1px;height:1px;overflow:hidden;clip:rect(0 0 0 0);white-space:nowrap;}

:focus-visible{outline:2.5px solid var(--volt);outline-offset:2px;border-radius:4px;}

/* ---------- Skip link ---------- */
.skip-link{position:absolute;left:12px;top:-60px;background:var(--volt);color:#fff;padding:10px 16px;border-radius:var(--radius-s);z-index:1000;transition:top .2s;}
.skip-link:focus{top:12px;}

/* ---------- Top utility bar ---------- */
.topbar{background:var(--ink-950);color:#C9CEDA;font-size:12.5px;}
.topbar .container{display:flex;justify-content:space-between;align-items:center;height:34px;gap:12px;}
.topbar a{opacity:.85;}
.topbar a:hover{opacity:1;color:#fff;}
.topbar-links{display:flex;gap:18px;}

/* ---------- Header / Nav ---------- */
.site-header{position:sticky;top:0;z-index:200;background:var(--header-bg);backdrop-filter:blur(14px);border-bottom:1px solid var(--border);}
.nav{display:flex;align-items:center;justify-content:space-between;height:68px;gap:16px;}
.brand{display:flex;align-items:center;gap:10px;font-family:var(--font-display);font-weight:700;font-size:19px;}
.brand-mark{width:34px;height:34px;flex:none;}
.brand small{display:block;font-family:var(--font-body);font-weight:500;font-size:11px;color:var(--text-dim);letter-spacing:.02em;}

.nav-links{display:flex;align-items:center;gap:4px;list-style:none;margin:0;padding:0;}
.nav-links>li{position:relative;}
.nav-links>li>a,.nav-links>li>button.nav-toplink{display:flex;align-items:center;gap:5px;padding:10px 12px;border-radius:var(--radius-s);font-weight:600;font-size:14.5px;background:none;border:none;color:var(--text);}
.nav-links>li>a:hover,.nav-links>li>button.nav-toplink:hover,.nav-links>li.open>button.nav-toplink{background:var(--surface-2);}
.chev{width:9px;height:9px;transition:transform .18s;}
.nav-links>li.open .chev{transform:rotate(180deg);}

.mega{
  position:absolute;
  top:100%;
  left:50%;
  transform:translateX(-50%);
  width:640px;
  max-width:min(640px, 92vw);
  background:var(--surface);
  border:1px solid var(--border);
  border-radius:var(--radius-m);
  box-shadow:var(--shadow);
  padding:18px;
  display:none;
  grid-template-columns:1fr 1fr;
  gap:4px 18px;
  z-index:50;
}
.mega.mega-left{left:0;transform:none;}
.nav-links>li.open .mega{display:grid;}
.mega a{display:block;padding:8px 10px;border-radius:var(--radius-s);font-size:13.5px;color:var(--text-dim);}
.mega a:hover{background:var(--surface-2);color:var(--volt);}

.nav-cta{display:flex;align-items:center;gap:10px;}
.btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;padding:10px 18px;border-radius:999px;font-weight:700;font-size:14.5px;border:1.5px solid transparent;transition:transform .15s,box-shadow .15s,background .15s,border-color .15s;white-space:nowrap;}
.btn:active{transform:translateY(1px);}
.btn-primary{background:var(--volt);color:#fff;box-shadow:0 6px 18px -6px rgba(47,111,237,.55);}
.btn-primary:hover{background:var(--volt-dim);}
.btn-ghost{background:transparent;border-color:var(--border);color:var(--text);}
.btn-ghost:hover{background:var(--surface-2);}
.btn-outline{background:transparent;border-color:currentColor;}
.btn:disabled{opacity:.6;cursor:not-allowed;transform:none;}

.theme-toggle{width:40px;height:40px;border-radius:50%;border:1.5px solid var(--border);background:var(--surface);display:flex;align-items:center;justify-content:center;flex:none;}
.theme-toggle svg{width:18px;height:18px;}
.theme-toggle .icon-moon{display:none;}
[data-theme="dark"] .theme-toggle .icon-sun{display:none;}
[data-theme="dark"] .theme-toggle .icon-moon{display:block;}

.menu-btn{display:none;width:42px;height:42px;border-radius:var(--radius-s);border:1.5px solid var(--border);background:var(--surface);align-items:center;justify-content:center;}
.menu-btn span,.menu-btn span::before,.menu-btn span::after{content:'';display:block;width:18px;height:2px;background:var(--text);position:relative;transition:.2s;}
.menu-btn span::before{position:absolute;top:-6px;}
.menu-btn span::after{position:absolute;top:6px;}

/* ---------- Breadcrumb ---------- */
.breadcrumb-bar{border-bottom:1px solid var(--border);background:var(--bg);}
.breadcrumb{list-style:none;display:flex;flex-wrap:wrap;align-items:center;gap:6px;margin:0;padding:12px 0;font-size:13px;color:var(--text-dim);}
.breadcrumb li:not(:last-child)::after{content:'/';margin-left:6px;color:var(--border);}
.breadcrumb a:hover{color:var(--volt);}
.breadcrumb li[aria-current] {color:var(--text);font-weight:600;}

/* ---------- Hero ---------- */
.hero{position:relative;padding:64px 0 56px;overflow:hidden;}
.hero::before{
  content:'';position:absolute;inset:-20% -10% auto -10%;height:520px;
  background:radial-gradient(60% 60% at 30% 20%, rgba(47,111,237,.16), transparent 70%),
             radial-gradient(50% 50% at 80% 10%, rgba(255,200,0,.14), transparent 70%);
  pointer-events:none;
}
.hero-grid{position:relative;display:grid;grid-template-columns:1.05fr .95fr;gap:44px;align-items:start;}
.eyebrow{display:inline-flex;align-items:center;gap:8px;font-size:12.5px;font-weight:700;letter-spacing:.06em;text-transform:uppercase;color:var(--volt-dim);background:rgba(47,111,237,.1);border:1px solid rgba(47,111,237,.25);padding:6px 12px;border-radius:999px;margin-bottom:16px;}
[data-theme="dark"] .eyebrow{color:#8FB4FF;}
.hero h1{font-size:clamp(30px,4vw,46px);}
.hero h1 .accent{color:var(--volt);}
.hero-sub{font-size:17px;color:var(--text-dim);max-width:52ch;}
.trust-row{display:flex;flex-wrap:wrap;gap:22px;margin-top:22px;font-size:13px;color:var(--text-dim);}
.trust-row span{display:flex;align-items:center;gap:7px;font-weight:600;}
.dot-good{width:7px;height:7px;border-radius:50%;background:var(--good);flex:none;}

/* ---------- Validator card ---------- */
.validator-card{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius-l);box-shadow:var(--shadow);padding:22px;position:relative;}
.tabs{display:flex;gap:6px;background:var(--surface-2);padding:4px;border-radius:999px;margin-bottom:16px;}
.tab{flex:1;padding:9px 10px;border:none;background:transparent;border-radius:999px;font-weight:700;font-size:13.5px;color:var(--text-dim);}
.tab[aria-selected="true"]{background:var(--surface);color:var(--text);box-shadow:0 2px 8px rgba(0,0,0,.08);}
.panel{display:none;}
.panel.active{display:block;}

.field{position:relative;}
.field input[type="url"],.field textarea{
  width:100%;border:1.5px solid var(--border);background:var(--bg);color:var(--text);
  border-radius:var(--radius-m);padding:14px 110px 14px 16px;font-size:14.5px;font-family:inherit;
  transition:border-color .15s, box-shadow .15s;
}
.field textarea{padding:14px 16px;min-height:190px;resize:vertical;font-family:ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;font-size:13px;line-height:1.55;}
.field input:focus,.field textarea:focus{border-color:var(--volt);box-shadow:0 0 0 4px rgba(47,111,237,.15);outline:none;}
.field input.field-error,.field textarea.field-error{border-color:var(--bad);}
.field-inline-btn{position:absolute;right:6px;top:6px;bottom:6px;}
.hint{font-size:12.5px;color:var(--text-dim);margin-top:8px;display:flex;align-items:center;gap:6px;}
.hint.error{color:var(--bad);font-weight:600;}
.upload-row{display:flex;align-items:center;gap:10px;margin-top:10px;}
.upload-row input[type=file]{font-size:12.5px;color:var(--text-dim);}

.validator-actions{display:flex;align-items:center;gap:12px;margin-top:16px;flex-wrap:wrap;}
.validator-actions .btn-primary{flex:1;min-width:180px;padding:14px 18px;font-size:15px;}
.count-badge{font-size:12px;color:var(--text-dim);}

.example-chips{display:flex;flex-wrap:wrap;gap:8px;margin-top:14px;}
.chip{font-size:12px;padding:6px 12px;border-radius:999px;border:1px solid var(--border);color:var(--text-dim);background:var(--surface-2);}
.chip:hover{border-color:var(--volt);color:var(--volt);}

/* signature: browser mockup with scan trace */
.scan-mock{margin-top:22px;border:1px solid var(--border);border-radius:var(--radius-m);overflow:hidden;background:var(--bg);position:relative;}
.scan-mock-bar{display:flex;align-items:center;gap:6px;padding:9px 12px;background:var(--surface-2);border-bottom:1px solid var(--border);}
.scan-mock-bar i{width:9px;height:9px;border-radius:50%;background:var(--border);}
.scan-mock-url{margin-left:8px;font-size:11.5px;color:var(--text-dim);font-family:ui-monospace,monospace;}
.scan-mock-body{height:90px;position:relative;background:
  repeating-linear-gradient(90deg, transparent, transparent 40px, var(--surface-2) 40px, var(--surface-2) 41px);
}
.scan-line{position:absolute;top:0;bottom:0;width:2px;background:linear-gradient(180deg, transparent, var(--bolt), var(--volt), transparent);opacity:0;filter:drop-shadow(0 0 8px var(--bolt));}
.scan-mock.scanning .scan-line{opacity:1;animation:scan-sweep 1.15s linear infinite;}
@keyframes scan-sweep{0%{left:0;}100%{left:100%;}}
.scan-mock.scanning .scan-mock-body::after{content:'Validating against AMP HTML spec…';position:absolute;inset:0;display:flex;align-items:center;justify-content:center;font-size:12px;color:var(--text-dim);background:var(--bg);}

/* ---------- Results ---------- */
.results-section{padding:56px 0 20px;scroll-margin-top:90px;}
.results-shell{display:none;}
.results-shell.show{display:block;}
.result-summary{display:flex;flex-wrap:wrap;gap:16px;align-items:center;justify-content:space-between;background:var(--surface);border:1px solid var(--border);border-radius:var(--radius-l);padding:22px;margin-bottom:22px;box-shadow:var(--shadow);}
.status-pill{display:inline-flex;align-items:center;gap:10px;font-family:var(--font-display);font-weight:700;font-size:20px;padding:10px 18px;border-radius:999px;}
.status-pill.pass{background:rgba(22,199,132,.12);color:var(--good);}
.status-pill.fail{background:rgba(255,71,87,.12);color:var(--bad);}
.status-pill svg{width:22px;height:22px;}
.result-meta{display:flex;gap:22px;flex-wrap:wrap;font-size:13.5px;color:var(--text-dim);}
.result-meta b{color:var(--text);font-family:var(--font-display);font-size:16px;}
.result-actions{display:flex;gap:10px;flex-wrap:wrap;}

.issue-list{display:flex;flex-direction:column;gap:12px;}
.issue{border:1px solid var(--border);border-left-width:4px;background:var(--surface);border-radius:var(--radius-m);padding:16px 18px;}
.issue.sev-error{border-left-color:var(--bad);}
.issue.sev-warning{border-left-color:var(--warn);}
.issue-head{display:flex;justify-content:space-between;gap:10px;font-size:13px;color:var(--text-dim);margin-bottom:6px;}
.issue-head b{color:var(--text);}
.sev-tag{font-weight:700;text-transform:uppercase;font-size:11px;letter-spacing:.04em;padding:2px 8px;border-radius:999px;}
.sev-tag.sev-error{background:rgba(255,71,87,.12);color:var(--bad);}
.sev-tag.sev-warning{background:rgba(255,168,62,.15);color:var(--warn);}
.issue-msg{font-size:14.5px;margin-bottom:6px;}
.issue-code{display:block;font-family:ui-monospace,monospace;font-size:12.5px;background:var(--surface-2);border-radius:6px;padding:8px 10px;overflow-x:auto;white-space:pre;}
.issue-empty{text-align:center;padding:40px 20px;color:var(--text-dim);}

/* ---------- Reference tools rail ---------- */
.tools-rail{padding:40px 0;background:var(--surface-2);border-top:1px solid var(--border);border-bottom:1px solid var(--border);}
.tools-rail h2{font-size:22px;}
.rail-track{display:flex;gap:12px;overflow-x:auto;padding-bottom:8px;scroll-snap-type:x proximity;}
.rail-track::-webkit-scrollbar{height:6px;}
.rail-track::-webkit-scrollbar-thumb{background:var(--border);border-radius:99px;}
.rail-card{scroll-snap-align:start;flex:none;width:210px;background:var(--surface);border:1px solid var(--border);border-radius:var(--radius-m);padding:14px;font-size:13px;font-weight:600;}
.rail-card:hover{border-color:var(--volt);color:var(--volt);}

/* ---------- Features ---------- */
.section{padding:72px 0;}
.section-head{max-width:640px;margin:0 auto 40px;text-align:center;}
.section-head h2{font-size:clamp(24px,3vw,32px);}
.section-head p{color:var(--text-dim);}
.feature-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:18px;}
.feature-card{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius-m);padding:22px;transition:transform .15s, box-shadow .15s;}
.feature-card:hover{transform:translateY(-3px);box-shadow:var(--shadow);}
.feature-icon{width:42px;height:42px;border-radius:12px;background:rgba(47,111,237,.12);display:flex;align-items:center;justify-content:center;margin-bottom:14px;}
.feature-icon svg{width:22px;height:22px;color:var(--volt);}
.feature-card h3{font-size:17px;}
.feature-card p{color:var(--text-dim);font-size:14px;margin:0;}

/* ---------- How it works ---------- */
.steps{display:grid;grid-template-columns:repeat(4,1fr);gap:18px;counter-reset:step;}
.step{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius-m);padding:22px;position:relative;}
.step-num{font-family:var(--font-display);font-size:13px;font-weight:800;color:var(--volt);letter-spacing:.05em;margin-bottom:10px;}
.step h3{font-size:16px;}
.step p{font-size:13.5px;color:var(--text-dim);margin:0;}

/* ---------- About / natural paragraph ---------- */
.about-copy{max-width:820px;margin:0 auto;}
.about-copy h2{text-align:center;}
.about-copy p{color:var(--text-dim);font-size:15.5px;}

/* ---------- FAQ ---------- */
.faq-list{max-width:800px;margin:0 auto;}
.faq-item{border-bottom:1px solid var(--border);}
.faq-q{width:100%;display:flex;justify-content:space-between;align-items:center;gap:14px;background:none;border:none;padding:18px 4px;text-align:left;font-family:var(--font-display);font-size:16px;font-weight:600;color:var(--text);}
.faq-q .plus{flex:none;width:20px;height:20px;position:relative;}
.faq-q .plus::before,.faq-q .plus::after{content:'';position:absolute;background:var(--volt);border-radius:2px;}
.faq-q .plus::before{width:14px;height:2px;top:9px;left:3px;}
.faq-q .plus::after{width:2px;height:14px;left:9px;top:3px;transition:transform .2s;}
.faq-item[data-open="true"] .plus::after{transform:rotate(90deg);}
.faq-a{max-height:0;overflow:hidden;transition:max-height .25s ease;}
.faq-item[data-open="true"] .faq-a{max-height:400px;}
.faq-a p{padding:0 4px 18px;color:var(--text-dim);font-size:14.5px;}

/* ---------- CTA ---------- */
.cta{background:linear-gradient(135deg, var(--volt) 0%, var(--volt-dim) 100%);border-radius:var(--radius-l);padding:48px;text-align:center;color:#fff;margin:0 24px;}
.cta h2{color:#fff;font-size:clamp(22px,3vw,30px);}
.cta p{color:rgba(255,255,255,.85);max-width:520px;margin:0 auto 22px;}
.cta-actions{display:flex;gap:12px;justify-content:center;flex-wrap:wrap;}
.cta .btn-ghost{background:rgba(255,255,255,.12);border-color:rgba(255,255,255,.4);color:#fff;}
.cta .btn-ghost:hover{background:rgba(255,255,255,.22);}

/* ---------- Footer ---------- */
.site-footer{background:var(--ink-950);color:#C9CEDA;padding:56px 0 0;margin-top:60px;}
.footer-grid{display:grid;grid-template-columns:1.3fr repeat(4,1fr);gap:26px;padding-bottom:36px;}
.footer-brand p{color:#8B93A7;font-size:13.5px;}
.footer-col h4{color:#fff;font-size:13px;text-transform:uppercase;letter-spacing:.05em;margin-bottom:14px;}
.footer-col ul{list-style:none;margin:0;padding:0;display:flex;flex-direction:column;gap:9px;}
.footer-col a{font-size:13.5px;color:#AEB4C6;}
.footer-col a:hover{color:#fff;}
.footer-bottom{border-top:1px solid #1E2740;padding:20px 0;display:flex;justify-content:space-between;flex-wrap:wrap;gap:12px;font-size:12.5px;color:#7C8399;}
.footer-legal-links{display:flex;gap:16px;flex-wrap:wrap;}
.disclaimer{font-size:12px;color:#5F6780;padding:16px 0 28px;border-top:1px solid #1E2740;margin-top:8px;max-width:980px;}

/* ---------- Cookie banner ---------- */
.cookie-banner{position:fixed;left:16px;right:16px;bottom:16px;max-width:520px;background:var(--surface);color:var(--text);border:1px solid var(--border);border-radius:var(--radius-m);box-shadow:var(--shadow);padding:18px;z-index:500;display:none;}
.cookie-banner.show{display:block;}
.cookie-banner p{font-size:13px;color:var(--text-dim);margin-bottom:12px;}
.cookie-actions{display:flex;gap:10px;justify-content:flex-end;}

/* ---------- Toast ---------- */
.toast{position:fixed;bottom:24px;left:50%;transform:translateX(-50%) translateY(20px);background:var(--ink-950);color:#fff;padding:12px 20px;border-radius:999px;font-size:13.5px;font-weight:600;opacity:0;pointer-events:none;transition:.25s;z-index:600;box-shadow:var(--shadow);}
.toast.show{opacity:1;transform:translateX(-50%) translateY(0);}

/* ---------- Skeleton / loading ---------- */
.spinner{width:18px;height:18px;border:2.5px solid rgba(255,255,255,.4);border-top-color:#fff;border-radius:50%;animation:spin .7s linear infinite;display:none;}
.btn-primary.loading .spinner{display:inline-block;}
.btn-primary.loading .btn-label{opacity:.85;}
@keyframes spin{to{transform:rotate(360deg);}}

/* ---------- Responsive ---------- */
@media (max-width:1080px){
  .hero-grid{grid-template-columns:1fr;}
  .feature-grid{grid-template-columns:repeat(2,1fr);}
  .steps{grid-template-columns:repeat(2,1fr);}
  .footer-grid{grid-template-columns:1fr 1fr 1fr;}
}
@media (max-width:860px){
  .topbar .topbar-links{display:none;}
  .nav-links{display:none;}
  .menu-btn{display:flex;}
  .nav-cta .btn-primary{display:none;}
}
@media (max-width:640px){
  html,body{width:100%;overflow-x:hidden;}
  .container{padding:0 16px;}
  .feature-grid,.steps{grid-template-columns:1fr;}
  .footer-grid{grid-template-columns:1fr 1fr;}
  .cta{margin:0 12px;padding:32px 20px;}
  .result-summary{flex-direction:column;align-items:flex-start;}
  .validator-actions .btn-primary{width:100%;}
  .field input[type="url"]{padding-right:16px;}
  .field-inline-btn{position:static;width:100%;margin-top:10px;}
}

/* Mobile drawer */
.mobile-drawer{position:fixed;inset:0;background:var(--bg);z-index:300;display:none;padding:20px;overflow-y:auto;}
.mobile-drawer.show{display:block;}
.mobile-drawer-head{display:flex;justify-content:space-between;align-items:center;margin-bottom:20px;}
.mobile-drawer nav ul{list-style:none;padding:0;margin:0;}
.mobile-drawer details{border-bottom:1px solid var(--border);padding:10px 0;}
.mobile-drawer summary{font-weight:700;font-size:15px;cursor:pointer;padding:6px 0;}
.mobile-drawer .sub-links{display:flex;flex-direction:column;gap:6px;margin:8px 0 4px;padding-left:8px;}
.mobile-drawer .sub-links a{font-size:13.5px;color:var(--text-dim);padding:4px 0;}
.mobile-drawer > nav > ul > li > a{display:block;padding:12px 0;font-weight:700;font-size:15px;border-bottom:1px solid var(--border);}

@media (prefers-reduced-motion: reduce){
  *{animation-duration:.001ms !important;animation-iteration-count:1 !important;transition-duration:.001ms !important;}
  html{scroll-behavior:auto;}
}