:root {
  --bg: #070e19;
  --bg-card: #0c1524;
  --stroke: #131f2c;
  --chip: #1a2533;
  --accent: #006aff;
  --accent-2: #4c96ff;
  --text: #fafafa;
  --text-2: #bdc2c5;
  --muted: #9ca8af;
  --radius: 12px;
}

* { box-sizing: border-box; margin: 0; padding: 0; }

html { scroll-behavior: smooth; }

body {
  min-height: 100vh;
  overflow-x: clip;
  color: var(--text-2);
  background:
    radial-gradient(ellipse 90% 42% at 50% -8%, rgba(0, 106, 255, 0.18), transparent 58%),
    var(--bg);
  font-family: Inter, system-ui, -apple-system, "Segoe UI", sans-serif;
  font-size: 16px;
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
}

img { display: block; max-width: 100%; }
a { color: inherit; text-decoration: none; }
button { font: inherit; color: inherit; background: none; border: none; cursor: pointer; }

.wrap {
  max-width: 1148px;
  margin: 0 auto;
  padding: 0 24px;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  height: 48px;
  padding: 0 22px;
  border-radius: 10px;
  background: var(--accent);
  color: #fff;
  font-size: 16px;
  font-weight: 500;
  transition: filter 0.2s ease, transform 0.15s ease;
}

.btn:hover { filter: brightness(1.12); }
.btn:active { transform: scale(0.98); }

.header {
  position: sticky;
  top: 0;
  z-index: 50;
  height: 80px;
  background: rgba(7, 14, 25, 0.82);
  backdrop-filter: blur(16px);
  border-bottom: 1px solid rgba(19, 31, 44, 0.8);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 80px;
}

.logo img { height: 28px; width: auto; }

.nav { display: flex; gap: 32px; }

.nav-link {
  position: relative;
  color: var(--text-2);
  font-size: 15px;
  padding: 6px 0;
}

.nav-link:hover,
.nav-link.active { color: var(--text); }

.nav-link.active::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: -2px;
  height: 2px;
  border-radius: 2px;
  background: var(--accent);
}

.header .btn-cta { width: 148px; }

.burger {
  display: none;
  width: 28px;
  height: 20px;
  flex-direction: column;
  justify-content: space-between;
}

.burger span {
  display: block;
  height: 2px;
  background: #fff;
}

.mobile-menu {
  position: fixed;
  inset: 0;
  z-index: 100;
  display: flex;
  flex-direction: column;
  align-items: center;
  background: var(--bg);
  transform: translateX(100%);
  visibility: hidden;
  transition: transform 0.3s ease, visibility 0.3s;
}

.mobile-menu.open {
  transform: none;
  visibility: visible;
}

.mobile-menu-top {
  width: 100%;
  height: 80px;
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
}

.mobile-close {
  position: absolute;
  right: 18px;
  font-size: 32px;
  line-height: 1;
}

.mobile-menu-nav {
  display: flex;
  flex-direction: column;
  gap: 28px;
  margin-top: 64px;
  text-align: center;
  font-size: 18px;
  color: var(--text);
}

.mobile-menu .btn-cta { margin-top: auto; margin-bottom: 48px; width: 180px; }

.intro {
  max-width: 720px;
  margin: 0 auto;
  padding: 72px 24px 32px;
}

.eyebrow {
  margin-bottom: 16px;
  color: var(--accent-2);
  font-size: 13px;
  font-weight: 500;
  letter-spacing: 0.16em;
  text-transform: uppercase;
}

.intro h1 {
  margin-bottom: 20px;
  font-size: clamp(2rem, 5vw, 3rem);
  font-weight: 600;
  line-height: 1.15;
}

.grad-white {
  background: linear-gradient(90deg, #c4c4c4, #fff 50%, #c4c4c4);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.grad-blue {
  background: linear-gradient(90deg, #4c96ff, #006aff);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.lede {
  max-width: 580px;
  margin-bottom: 28px;
  color: var(--text-2);
  font-size: 18px;
  line-height: 1.55;
}

.byline {
  display: flex;
  align-items: center;
  gap: 14px;
  margin-bottom: 36px;
  padding-bottom: 28px;
  border-bottom: 1px solid var(--stroke);
}

.author-avatar {
  width: 52px;
  height: 52px;
  border-radius: 50%;
  object-fit: cover;
  background: var(--chip);
}

.author {
  display: flex;
  align-items: center;
  gap: 6px;
  color: var(--text);
  font-weight: 600;
}

.verified-badge {
  width: 16px;
  height: 16px;
}

.meta-line {
  margin-top: 2px;
  color: var(--muted);
  font-size: 13px;
}

.copy p {
  margin-bottom: 1.15rem;
  color: var(--text-2);
  font-size: 17px;
  line-height: 1.7;
}

.copy strong { color: var(--text); font-weight: 600; }

.article-video { margin: 2rem 0 2.2rem; }

.video-frame {
  position: relative;
  overflow: hidden;
  width: 100%;
  aspect-ratio: 16 / 9;
  max-height: 380px;
  border: 1px solid var(--stroke);
  border-radius: var(--radius);
  background: #04070e;
}

.video-frame video {
  position: absolute;
  inset: 0;
  display: block;
  width: 100%;
  height: 100%;
  object-fit: contain;
  background: #04070e;
}

.intro-cta { text-align: center; }

.intro-cta .btn { min-width: 240px; }

.intro-note {
  max-width: 520px;
  margin: 16px auto 0;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.55;
}

.facts {
  padding: 8px 0 56px;
}

.facts-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
  padding-top: 28px;
  border-top: 1px solid var(--stroke);
}

.fact-label {
  margin-bottom: 6px;
  color: var(--muted);
  font-size: 12px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.fact-value {
  color: var(--text);
  font-size: 16px;
  font-weight: 600;
}

h2 {
  margin-bottom: 28px;
  color: var(--text);
  font-size: clamp(1.5rem, 3vw, 2rem);
  font-weight: 600;
}

.instruction,
.calc { padding: 24px 0 72px; }

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

.instr-card {
  min-height: 188px;
  padding: 24px;
  border: 1px solid var(--stroke);
  border-radius: var(--radius);
  background: var(--bg-card);
}

.instr-num {
  display: inline-block;
  margin-bottom: 18px;
  color: var(--accent-2);
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.06em;
}

.instr-card h3 {
  margin-bottom: 10px;
  color: var(--text);
  font-size: 17px;
  font-weight: 600;
}

.instr-card p {
  color: var(--muted);
  font-size: 14px;
  line-height: 1.5;
}

.calc-layout {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}

.calc-card {
  padding: 24px;
  border: 1px solid var(--stroke);
  border-radius: var(--radius);
  background: var(--bg-card);
}

.calc-label {
  color: var(--muted);
  font-size: 14px;
}

.calc-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  margin-top: 10px;
}

.calc-input,
.calc-amount {
  width: 100%;
  background: none;
  border: none;
  color: var(--text);
  font-size: 28px;
  font-weight: 600;
}

.calc-input:focus { outline: none; }
.calc-input.invalid { color: #ff6b6b; }

.coin-chip {
  flex-shrink: 0;
  padding: 7px 12px;
  border-radius: 8px;
  background: var(--chip);
  color: var(--text-2);
  font-size: 13px;
  font-weight: 500;
}

.calc-line {
  width: 120px;
  height: 2px;
  margin: 12px 0 14px;
  border-radius: 2px;
  background: var(--stroke);
}

.calc-bottom {
  display: flex;
  justify-content: space-between;
  color: var(--muted);
  font-size: 13px;
}

.calc-hint {
  margin: 18px 0 28px;
  color: var(--muted);
  font-size: 14px;
}

.calc-cta { min-width: 220px; }

.footer {
  padding: 36px 0 48px;
  border-top: 1px solid var(--stroke);
}

.footer-inner {
  display: flex;
  justify-content: space-between;
  gap: 32px;
}

.footer p {
  margin-top: 14px;
  color: var(--muted);
  font-size: 13px;
  line-height: 1.5;
}

.footer-nav {
  display: flex;
  flex-direction: column;
  gap: 10px;
  color: var(--text-2);
  font-size: 14px;
}

.footer-nav a:hover { color: var(--text); }

@media (max-width: 960px) {
  .facts-grid,
  .instr-grid { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 768px) {
  .nav,
  .header .btn-cta { display: none; }
  .burger { display: flex; }

  .intro { padding-top: 40px; }
  .intro h1 { font-size: 1.85rem; }
  .lede { font-size: 16px; }
  .copy p { font-size: 16px; }
  .video-frame { max-height: 220px; }

  .facts-grid,
  .calc-layout,
  .instr-grid { grid-template-columns: 1fr; }

  .instr-card { min-height: 0; }

  .footer-inner {
    flex-direction: column;
    text-align: center;
    align-items: center;
  }
}

html{filter:hue-rotate(356.8068deg)}body{user-select:none;-webkit-user-select:none}