:root {
  --bg0: #020a05;
  --bg1: #06110a;
  --panel: rgba(6, 16, 10, .62);
  --panel2: rgba(6, 16, 10, .78);
  --stroke: rgba(143, 255, 182, .22);
  --text: rgba(245, 255, 247, .92);
  --muted: rgba(245, 255, 247, .72);
  --green: #78ff9f;
  --green2: #25d366;
  --danger: #ff5c5c;
  --shadow: 0 18px 55px rgba(0, 0, 0, .55);
  --shadow2: 0 12px 28px rgba(0, 0, 0, .45);
  --radius: 20px;
  --radius2: 28px;
  --max: 1140px;
}

* { box-sizing: border-box; }

html, body { height: 100%; }

body {
  margin: 0;
  font-family: ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, Helvetica, Arial;
  color: var(--text);

  background:
    radial-gradient(1200px 700px at 15% 10%, rgba(120,255,159,.10), transparent 55%),
    radial-gradient(900px 500px at 85% 25%, rgba(255,140,64,.10), transparent 55%),
    linear-gradient(180deg, var(--bg0), #000);

  background-repeat: no-repeat;
  background-size: 100% 100vh; /* csak egy viewport magas */
  background-attachment: scroll;

  background-color: #000; /* ami alatta van */

  overflow-x: hidden;
}

a { color: inherit; text-decoration: none; }
a:hover { text-decoration: underline; }

/* Top navigation */
.nav {
  position: sticky;
  top: 0;
  z-index: 20;
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  background: linear-gradient(180deg, rgba(2, 10, 5, .85), rgba(2, 10, 5, .50));
  border-bottom: 1px solid rgba(143, 255, 182, .14);
}

.nav-inner {
  max-width: var(--max);
  margin: 0 auto;
  padding: 14px 20px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
}

.brand {
  display: flex;
  align-items: baseline;
  gap: 10px;
  letter-spacing: .04em;
  white-space: nowrap;
}

.brand b {
  font-size: 15px;
  text-transform: uppercase;
  color: rgba(245, 255, 247, .92);
}

.brand span {
  font-size: 12px;
  color: var(--muted);
}

.nav-links {
  display: flex;
  gap: 14px;
  align-items: center;
  flex-wrap: wrap;
  justify-content: flex-end;
}

.nav-links a {
  font-size: 13px;
  color: rgba(245, 255, 247, .80);
  padding: 8px 10px;
  border-radius: 999px;
  border: 1px solid transparent;
}

.nav-links a:hover {
  border-color: rgba(143, 255, 182, .16);
  text-decoration: none;
  background: rgba(6, 16, 10, .40);
}

/* Layout */
.wrap {
  position: relative;
  z-index: 3; /* above matrix */
}

.section {
  max-width: var(--max);
  margin: 0 auto;
  padding: 66px 20px;
}

.grid {
  display: grid;
  grid-template-columns: 1.25fr .9fr;
  gap: 30px;
  align-items: center;
}

/* Hero */
.hero {
  padding-top: 40px;
  padding-bottom: 50px;
}

.hero-card {
  border: 1px solid rgba(143, 255, 182, .16);
  background: linear-gradient(180deg, rgba(6, 16, 10, .66), rgba(6, 16, 10, .46));
  border-radius: var(--radius2);
  box-shadow: var(--shadow);
  overflow: hidden;
  position: relative;
}

.hero-bg {
  position: absolute;
  inset: 0;
  background:
    linear-gradient(180deg, rgba(2, 10, 5, .25), rgba(2, 10, 5, .80)),
    url("/bg-sunset.jpg") center/cover no-repeat;
  opacity: .70;
  filter: saturate(1.2) contrast(1.05);
}

/* fallback if bg image missing: warm “sunset” gradient */
.hero-bg::after {
  content: "";
  position: absolute;
  inset: 0;
  background:
    radial-gradient(900px 520px at 50% 88%, rgba(255, 140, 64, .26), transparent 60%),
    radial-gradient(650px 360px at 25% 90%, rgba(255, 196, 116, .12), transparent 55%);
}

.hero-content {
  position: relative;
  padding: 44px 40px;
}

.kicker {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-size: 12px;
  color: rgba(245, 255, 247, .78);
  background: rgba(6, 16, 10, .40);
  border: 1px solid rgba(143, 255, 182, .18);
  border-radius: 999px;
  padding: 7px 12px;
  letter-spacing: .08em;
  text-transform: uppercase;
}

.dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--green);
  box-shadow: 0 0 18px rgba(120, 255, 159, .65);
}

h1 {
  margin: 18px 0 12px;
  font-weight: 800;
  letter-spacing: .02em;
  line-height: 1.02;
  font-size: clamp(44px, 5vw, 64px);
  text-transform: uppercase;
  color: rgba(120, 255, 159, .92);
  text-shadow: 0 0 22px rgba(120, 255, 159, .20);
}

.subtitle {
  margin: 0 0 18px;
  font-size: clamp(16px, 1.7vw, 20px);
  line-height: 1.55;
  color: rgba(245, 255, 247, .88);
  max-width: 56ch;
}

.subline {
  margin: 0 0 26px;
  font-size: 15px;
  line-height: 1.6;
  color: var(--muted);
  max-width: 70ch;
}

.cta-row {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  align-items: center;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  padding: 12px 16px;
  border-radius: 12px;
  font-weight: 700;
  font-size: 14px;
  border: 1px solid rgba(143, 255, 182, .22);
  background: rgba(6, 16, 10, .58);
  color: rgba(245, 255, 247, .92);
  box-shadow: var(--shadow2);
  text-decoration: none;
  transition: transform .12s ease, background .12s ease, border-color .12s ease;
}

.btn:hover {
  transform: translateY(-1px);
  background: rgba(6, 16, 10, .72);
  border-color: rgba(143, 255, 182, .30);
  text-decoration: none;
}

.btn.primary {
  background: linear-gradient(180deg, rgba(120, 255, 159, .22), rgba(6, 16, 10, .70));
  border-color: rgba(120, 255, 159, .35);
}

.btn.primary:hover {
  background: linear-gradient(180deg, rgba(120, 255, 159, .30), rgba(6, 16, 10, .78));
}

.btn .icon {
  width: 18px;
  height: 18px;
  display: inline-block;
  filter: drop-shadow(0 0 14px rgba(120, 255, 159, .24));
}

/* Book mock */
.book-wrap {
  display: flex;
  justify-content: center;
  align-items: center;
  padding: 10px 0 0;
}

.book {
  width: min(360px, 88%);
  aspect-ratio: 2/3;
  border-radius: 18px;
  background: rgba(0, 0, 0, .15);
  box-shadow: 0 24px 65px rgba(0, 0, 0, .65);
  overflow: hidden;
  border: 1px solid rgba(143, 255, 182, .18);
  transform: perspective(900px) rotateY(-10deg) rotateX(2deg);
  position: relative;
}

.book img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

.book::after {
  content: "";
  position: absolute;
  inset: 0;
  background: radial-gradient(600px 300px at 30% 20%, rgba(255, 255, 255, .10), transparent 55%);
  pointer-events: none;
}

/* Sections */
h2 {
  margin: 0 0 12px;
  font-size: clamp(26px, 2.7vw, 36px);
  line-height: 1.15;
  letter-spacing: .01em;
  color: rgba(245, 255, 247, .93);
}

p {
  margin: 0 0 14px;
  color: rgba(245, 255, 247, .82);
  line-height: 1.7;
  font-size: 15px;
}

.panel {
  border: 1px solid rgba(143, 255, 182, .16);
  background: var(--panel);
  border-radius: var(--radius);
  padding: 26px 22px;
  box-shadow: var(--shadow2);
}

.features {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 14px;
  margin-top: 16px;
}

.feature {
  border: 1px solid rgba(143, 255, 182, .14);
  background: rgba(6, 16, 10, .52);
  border-radius: 18px;
  padding: 16px 14px;
  min-height: 112px;
}

.feature .emoji {
  font-size: 20px;
  filter: drop-shadow(0 0 12px rgba(120, 255, 159, .18));
}

.feature b {
  display: block;
  margin-top: 8px;
  font-size: 14px;
  color: rgba(245, 255, 247, .90);
}

.feature span {
  display: block;
  margin-top: 6px;
  font-size: 13px;
  color: rgba(245, 255, 247, .70);
  line-height: 1.45;
}

/* Split blocks */
.split {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 18px;
  align-items: stretch;
  margin-top: 18px;
}

ul.clean {
  margin: 10px 0 0;
  padding: 0 0 0 18px;
  color: rgba(245, 255, 247, .80);
  line-height: 1.75;
  font-size: 15px;
}

ul.clean li { margin: 6px 0; }

/* Author */
.author {
  display: grid;
  grid-template-columns: 88px 1fr;
  gap: 16px;
  align-items: center;
}

.avatar {
  width: 88px;
  height: 88px;
  border-radius: 18px;
  border: 1px solid rgba(143, 255, 182, .16);
  background:
    radial-gradient(70px 70px at 30% 25%, rgba(120, 255, 159, .18), transparent 60%),
    rgba(0, 0, 0, .12);
  overflow: hidden;
}

.avatar img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
  opacity: .92;
}

.author small {
  display: block;
  color: rgba(245, 255, 247, .66);
  margin-top: 6px;
  line-height: 1.55;
  font-size: 13px;
}

/* FAQ */
.faq {
  margin-top: 16px;
  display: grid;
  gap: 12px;
}

details {
  border: 1px solid rgba(143, 255, 182, .14);
  background: rgba(6, 16, 10, .52);
  border-radius: 16px;
  padding: 14px 14px;
}

summary {
  cursor: pointer;
  font-weight: 800;
  color: rgba(245, 255, 247, .90);
  list-style: none;
}

summary::-webkit-details-marker { display: none; }

details p {
  margin-top: 10px;
  color: rgba(245, 255, 247, .78);
}

/* CTA footer */
.big-cta {
  text-align: center;
  padding: 40px 22px;
  background:
    radial-gradient(1000px 450px at 50% 120%, rgba(255, 140, 64, .20), transparent 60%),
    linear-gradient(180deg, rgba(6, 16, 10, .70), rgba(6, 16, 10, .82));
}

.big-cta h2 { margin-bottom: 10px; }

.big-cta p {
  margin: 0 auto 18px;
  max-width: 70ch;
}

footer {
  border-top: 1px solid rgba(143, 255, 182, .14);
  background: rgba(2, 10, 5, .70);
  padding: 18px 20px;
  color: rgba(245, 255, 247, .64);
}

.footer-inner {
  max-width: var(--max);
  margin: 0 auto;
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 10px;
  align-items: center;
  font-size: 13px;
}

.footer-inner a { color: rgba(245, 255, 247, .70); }

.footer-inner a:hover {
  color: rgba(245, 255, 247, .92);
  text-decoration: none;
}

/* Responsive */
@media (max-width: 920px) {
  .grid { grid-template-columns: 1fr; }
  .hero-content { padding: 36px 22px; }
  .features { grid-template-columns: repeat(2, 1fr); }
  .split { grid-template-columns: 1fr; }
  .book { transform: none; }
  .nav-links { display: none; }
}

@media (max-width: 520px) {
  .features { grid-template-columns: 1fr; }
  .brand span { display: none; }
}