:root {
  color-scheme: dark;
  --bg: #07111f;
  --panel: #0c192a;
  --panel-2: #101f32;
  --line: rgba(151, 176, 201, .18);
  --text: #f4f8fb;
  --muted: #9fb0c2;
  --green: #37e6a1;
  --green-2: #9af6d2;
  --warning: #ffcf5c;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  min-width: 320px;
  background: var(--bg);
  color: var(--text);
  font-family: "DM Sans", system-ui, sans-serif;
  font-size: 16px;
  line-height: 1.6;
}

.grid {
  position: fixed;
  inset: 0;
  pointer-events: none;
  opacity: .28;
  background-image: linear-gradient(var(--line) 1px, transparent 1px), linear-gradient(90deg, var(--line) 1px, transparent 1px);
  background-size: 72px 72px;
  mask-image: linear-gradient(to bottom, #000 0, transparent 75%);
}

main { position: relative; width: min(1160px, calc(100% - 40px)); margin: auto; }
.topbar { display: flex; justify-content: space-between; align-items: center; padding: 30px 0; border-bottom: 1px solid var(--line); }
.brand { display: inline-flex; align-items: center; gap: 13px; color: var(--text); text-decoration: none; font: 700 .78rem/1 "Space Mono", monospace; letter-spacing: .08em; }
.brand em { color: var(--green); font-style: normal; }
.brand-mark { width: 30px; height: 30px; display: grid; grid-template-columns: repeat(2, 1fr); gap: 4px; padding: 5px; border: 1px solid var(--green); }
.brand-mark i { border: 2px solid var(--green); }
.status { color: var(--muted); font-size: .86rem; }
.status b { display: inline-block; width: 7px; height: 7px; margin-right: 7px; background: var(--green); border-radius: 50%; box-shadow: 0 0 12px var(--green); }

.hero { position: relative; padding: 105px 0 80px; }
.eyebrow { margin-bottom: 23px; color: var(--muted); font: 700 .75rem/1.4 "Space Mono", monospace; letter-spacing: .14em; }
.eyebrow span { color: var(--green); }
h1 { max-width: 900px; margin: 0; font-size: clamp(3rem, 7.5vw, 6.7rem); line-height: .98; letter-spacing: -.065em; font-weight: 500; }
h1 strong { color: var(--green); font-weight: 500; }
.lead { max-width: 640px; margin: 36px 0 65px; color: var(--muted); font-size: clamp(1.05rem, 2vw, 1.25rem); }

.signal { position: absolute; right: 5%; top: 95px; width: 180px; height: 180px; opacity: .9; }
.qr-frame { width: 100%; height: 100%; display: grid; place-items: center; border: 1px solid var(--green); color: var(--green); font: 400 4rem/1 "Space Mono"; box-shadow: inset 0 0 40px rgba(55,230,161,.08); clip-path: polygon(0 0, 38% 0, 38% 2%, 62% 2%, 62% 0, 100% 0, 100% 38%, 98% 38%, 98% 62%, 100% 62%, 100% 100%, 62% 100%, 62% 98%, 38% 98%, 38% 100%, 0 100%, 0 62%, 2% 62%, 2% 38%, 0 38%); }
.scan-line { position: absolute; z-index: 2; left: 8px; right: 8px; height: 1px; background: var(--green); box-shadow: 0 0 15px var(--green); animation: scan 3s ease-in-out infinite; }
@keyframes scan { 0%,100% { top: 14px; opacity:.5 } 50% { top: 165px; opacity:1 } }

.lesson-grid { display: grid; grid-template-columns: repeat(3, 1fr); border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }
.lesson-grid article { padding: 34px 34px 38px 0; }
.lesson-grid article + article { padding-left: 34px; border-left: 1px solid var(--line); }
.number { color: var(--green); font: 700 .75rem/1 "Space Mono"; }
.lesson-grid h2 { margin: 24px 0 9px; font-size: 1.13rem; }
.lesson-grid p { margin: 0; color: var(--muted); font-size: .95rem; }

.challenge { display: grid; grid-template-columns: minmax(0, 1.5fr) minmax(300px, .7fr); gap: 80px; padding: 110px 0; }
.challenge h2 { margin: 0 0 18px; font-size: clamp(2.25rem, 5vw, 4.7rem); line-height: 1; letter-spacing: -.05em; }
.challenge-copy > p { max-width: 700px; color: var(--muted); }
.trap-link { width: 100%; display: grid; grid-template-columns: auto 1fr auto; align-items: center; gap: 18px; margin-top: 36px; padding: 20px; text-align: left; border: 1px solid rgba(55,230,161,.45); border-radius: 4px; background: rgba(55,230,161,.05); color: var(--green-2); cursor: pointer; font: 500 .92rem/1.5 "Space Mono", monospace; transition: .2s ease; }
.trap-link:hover, .trap-link:focus-visible { outline: none; background: rgba(55,230,161,.1); border-color: var(--green); transform: translateY(-2px); }
.trap-link small { display: block; color: var(--text); font: 600 .9rem/1.3 "DM Sans", sans-serif; }
.link-icon { display: grid; place-items: center; width: 42px; height: 42px; border-radius: 50%; background: var(--green); color: var(--bg); font-size: 1.3rem; }
.arrow { font-size: 1.4rem; }
.hint { font-size: .85rem; }

.check-card { align-self: end; padding: 30px; background: var(--panel); border: 1px solid var(--line); border-top: 3px solid var(--green); }
.card-label { margin: 0 0 24px; color: var(--green); font: 700 .74rem/1 "Space Mono", monospace; letter-spacing: .12em; }
.check-card ul { list-style: none; margin: 0; padding: 0; }
.check-card li { display: grid; grid-template-columns: 22px 1fr; gap: 9px; padding: 15px 0; border-top: 1px solid var(--line); color: var(--muted); font-size: .9rem; }
.check-card li span { color: var(--green); }

footer { display: flex; justify-content: space-between; align-items: center; gap: 30px; padding: 32px 0 40px; border-top: 1px solid var(--line); }
footer div > span { color: var(--muted); font: 700 .68rem/1 "Space Mono", monospace; letter-spacing: .12em; }
footer p { margin: 5px 0 0; }
.linkedin, .safe-link { color: var(--bg); background: var(--green); padding: 14px 20px; border-radius: 3px; text-decoration: none; font-weight: 700; transition: .2s ease; }
.linkedin:hover, .linkedin:focus-visible, .safe-link:hover, .safe-link:focus-visible { background: var(--green-2); outline: 3px solid rgba(55,230,161,.2); outline-offset: 3px; }

dialog { width: min(680px, calc(100% - 30px)); padding: 42px; color: var(--text); background: var(--panel-2); border: 1px solid rgba(55,230,161,.45); border-radius: 6px; box-shadow: 0 30px 100px rgba(0,0,0,.65); }
dialog::backdrop { background: rgba(2, 7, 14, .84); backdrop-filter: blur(8px); }
dialog[open] { animation: reveal .25s ease-out; }
@keyframes reveal { from { opacity:0; transform: translateY(12px) scale(.98) } }
.close { position: absolute; top: 14px; right: 17px; border: 0; background: transparent; color: var(--muted); font-size: 2rem; cursor: pointer; }
.dialog-icon { display: grid; place-items: center; width: 58px; height: 58px; margin-bottom: 24px; border: 1px solid var(--warning); color: var(--warning); font: 700 1.5rem/1 "Space Mono"; }
dialog h2 { margin: 0 0 15px; font-size: clamp(2rem, 5vw, 3.3rem); line-height: 1.04; letter-spacing: -.045em; }
dialog > p { color: var(--muted); }
.url-compare { margin: 28px 0; border: 1px solid var(--line); }
.url-compare div { padding: 15px 18px; }
.url-compare div + div { border-top: 1px solid var(--line); }
.url-compare small { display: block; margin-bottom: 4px; color: var(--muted); font: 700 .65rem/1.4 "Space Mono"; letter-spacing: .08em; }
.url-compare span { overflow-wrap: anywhere; font: 400 .84rem/1.5 "Space Mono"; }
.url-compare .actual span { color: var(--warning); }
.takeaway { padding-left: 16px; border-left: 2px solid var(--green); }
.safe-link { display: inline-flex; gap: 10px; margin-top: 12px; }
.safe-destination { display: block; margin-top: 12px; color: var(--muted); font-family: "Space Mono", monospace; }

@media (max-width: 800px) {
  main { width: min(100% - 28px, 680px); }
  .topbar { padding: 20px 0; }
  .status { display: none; }
  .hero { padding-top: 72px; }
  .signal { width: 90px; height: 90px; right: 0; top: 54px; opacity: .45; }
  .scan-line { animation: none; top: 45px; }
  .qr-frame { font-size: 2rem; }
  h1 { max-width: 90%; }
  .lead { margin: 28px 0 48px; }
  .lesson-grid { grid-template-columns: 1fr; }
  .lesson-grid article, .lesson-grid article + article { padding: 26px 0; border-left: 0; }
  .lesson-grid article + article { border-top: 1px solid var(--line); }
  .challenge { grid-template-columns: 1fr; gap: 44px; padding: 80px 0; }
  .trap-link { grid-template-columns: auto 1fr; }
  .trap-link .arrow { display: none; }
  footer { align-items: flex-start; flex-direction: column; }
  dialog { padding: 34px 22px 28px; }
  .safe-link { width: 100%; justify-content: center; text-align: center; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { scroll-behavior: auto !important; animation: none !important; transition: none !important; }
}